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O-Saft is an easy to use tool to show information about SSL certificates and tests the SSL connection according to a given list of ciphers and various SSL configurations.

It’s designed to be used by penetration testers, security auditors or server administrators. The idea is to show the important information or the special checks with a simple call of the tool. However, it provides a wide range of options so that it can be used for comprehensive and special checks by experienced people.

Installed size: 2.06 MB
How to install: sudo apt install o-saft

  • libio-socket-ssl-perl
  • libnet-dns-perl
  • libnet-ssleay-perl
  • libreadonly-perl
  • openssl
  • perl
root@kali:~# o-saft --help


        O-Saft - OWASP SSL advanced forensic tool
                 OWASP SSL audit for testers


        This tools lists  information  about remote target's  SSL certificate
        and tests the remote target according given list of ciphers.

        Note:  Throughout this description  `$0'  is used as an alias for the
        program name  ''.

SYNOPSIS [COMMANDS ..] [OPTIONS ..] target [target target ...]

        where  [COMMANDS]  and  [OPTIONS]  are described below  and target is
        a hostname either as full qualified domain name or as IP address.
        Multiple commands and targets may be combined.

        All  commands  and  options  can also be specified in a  rc-file, see
        RC-FILE  below.

        I.g. all commands start with a  '+'  character and options start with
        '-'  or  '--'  characters. Anything else is treated as target name.


        Before going into  a detailed description  of the  purpose and usage,
        here are some examples of the most common use cases:

        * Show supported (enabled) ciphers of target:
 +cipher --enabled example.tld

        * Show supported (enabled) ciphers with their DH parameters:
 +cipher-dh example.tld

        * Test all ciphers, even if not supported by local SSL implementation:
 +cipherall example.tld

        * Show details of certificate and connection of target:
 +info example.tld

        * Check certificate, ciphers and SSL connection of target:
 +check example.tld

        * Check connection to target for vulnerabilities:
 +vulns example.tld

        * Check for all known ciphers (independant of SSL library):
 +cipherraw example.tld --range=full
 example.tld --range=full --v

        * Get the certificate's Common Name for a bunch of servers:
 +cn example.tld some.tld other.tld

        * List more usage examples

        * List all available commands:

        * Get table of contents for complete help

        * Show just one section, for example SECURITY, from help

        * Start the simple GUI

        * Start the simple GUI which uses in a Docker image
          o-saft.tcl --docker

        For more specialised test cases, refer to the sections  COMMANDS  and
        OPTIONS  below. For more examples please refer to  EXAMPLES  section.

        For more details, please see  Requirements  and  INSTALLATION  below.


        Why a new tool for checking SSL security and configuration when there
        are already a dozen or more such good tools in existence (in 2012)?

        Unique features:
          * working in closed environments, i.e. without internet connection
          * checking availability of ciphers independent of installed library
          * checking for all possible ciphers (up to 65535 per SSL protocol)
          * mainly same results on all platforms.

        Currently available tools suffer from some or all of following issues:
          * lack of tests of unusual SSL certificate configurations
          * may return different results for the same checks on given target
          * missing tests for modern SSL/TLS functionality
          * missing tests for specific, known SSL/TLS vulnerabilities
          * no support for newer, advanced, features e.g. CRL, OCSP, EV
          * limited capability to create your own customised tests

        Other  reasons or problems  are that other tools are either binary or
        use additional binaries and hence are not portable to other platforms.

        In contrast to (all?) most other tools, including "openssl(1)", it can
        be used to "ask simple questions" like "does target support STS" just
        by calling:
 +hsts_sts example.tld

        For more, please see  EXAMPLES  section below.
        If it should run on systems with old software (perl or perl modules),
        please see  DEBUG  section below.


        This tool is designed to be used by people doing security or forensic
        analyses. Hence no malicious input is expected.

        There are no special security checks implemented. Some parameters are
        roughly sanatised according unwanted characters.  In particular there
        are no checks according any kind of code injection.

        Care should be taken, when additional tools and modules are installed
        as described in  INSTALLATION  below. In particular it is recommended
        to do these installations into directoies  specially prepared for use
        with . No other tools of your system should use these installations
        i.e. by accident or because your environment variables point to them.

        Note that compilation and installation of additional tools  (openssl,
        Net::SSLeay, etc.) uses known insecure configurations and features!
        This is essential to make able to check for such insecurities.

        It is  highly recommended to do these installations and use the tools
        on a separate testing system.



        The purpose of  O-Saft  is to do the work, not to force the user to
        learn a new tool or to install "newer" software first.
        However, the user "should do something" if necessary depending on the
        reported results.


        Results of checks are marked  'yes'  or 'no'.  This leaves the proper
        interpretation, if the result is "good" or "bad", to the user.
        Background:  it is not always possible to rate a result as  "good" or
        "bad" or "insecure" or whatever. That's why  O-Saft  can not give the
        "the best" or a "proper" recomendation. In practice it depends on the
        context what a recomendation, or countermeasure should be. That's why
        all results are marked  'yes'  or  'no'  if considered "questionable"
        or "not good" (for example according other checks).

        ... more comming soon ...


        It is important to understand, which provided information is based on
        data returned by underlaying (used) libraries and the information
        computed directly.

    OpenSSL, libssl, libcrypto

        In general the tool uses perl's "Net::SSLeay(1)" module  which itself
        is based on libssl and/or libssleay library of the operating system.
        It's possible to use other versions of these libraries, see options:
          * --exe-path=PATH --exe=PATH
          * --lib-path=PATH --lib=PATH
          * --envlibvar=NAME

        The external "openssl(1)" is called to extract  some information from
        its output.  The version of openssl can be controlled  with following
          * --openssl=TOOL
          * --no-openssl
          * --force-openssl
          * --exe-path=PATH --exe=PATH

        Above applies to all commands except  +cipherall and +cipherraw which
        uses no other libraries.

        OpenSSL is recommended to be used for libssl and libcrypto.  Versions
        0.9.8k to 1.0.2e (Jan. 2016) are known to work. However, versions be-
        for 1.0.0 may not provide all informations.
        LibreSSL is not recommended, because  some functionallity  considered
        insecure, has been removed.
        For more details, please see  INSTALLATION  below.

    Certificates and CA

        All checks according the validity of the certificate chain  are based
        on the root CAs installed on the system. NOTE that "Net::SSLeay(1)" and
       "openssl(1)" may have their own rules where to find the root CAs.
        Please refer to the documentation on your system for these tools.
        However, there are folloing options to tweak these rules:
          * --ca-file=FILE
          * --ca-path=DIR
          * --ca-depth=INT

    Commands and options

        All arguments  starting with  '+'  are considered  COMMANDS  for this
        tool. All arguments starting with  '--'  are considered  OPTIONS  for
        this tool.

        Reading any data from STDIN or here-documents is not yet supported.
        It's reserved for future use.

    Environment variables

        Following environment variables are incorporated:
          * LD_LIBRARY_PATH - used and extended with definitions from options
          * OPENSSL         - if set, full path to openssl executable
          * OPENSSL_CONF    - if set, full path to openssl's openssl.cnf or
                              directory where to find openssl.cnf


        For checking all ciphers and all protocols with  +cipherall  command,
        just perl (5.x) without any modules is required.

        For  +info  and  +check  (and all related) commands,  perl (5.x) with
        following modules (minimal version) is recommended:

          * IO               1.25 (2011)
          * IO::Socket::INET 1.37 (2011)
          * IO::Socket::SSL  1.90 (2013)
          * Net::DNS         0.66 (2011)
          * Net::SSLeay      1.49 (2012)

        However, it is recommended to use the most recent version of the mod-
        ules which then gives more accurate results and less warnings. If the
        modules are missing, they can be installed i.e. with:

              cpan Net::SSLeay

        Note: if you want to use advanced features of openssl or Net::SSLeay,
        please see  INSTALLATION section how to compile and install the tools
        fully customized.

        Also an openssl executable should be available, but is not mandatory.

        For checking DH parameters of ciphers, openssl 1.0.2  or newer should
        be available. If an older version of openssl is found, we try hard to
        extract  the DH parameters from the  data returned by the server, see
        +cipher-dh  command.

        If you need to run on systems with older perl or perl module versions
        please refer to the  DEBUG  section for more inofrmation.


        All output is designed to be easily parsed by postprocessors.  Please
        see  OUTPUT  section below for details.

        For the results,  we have to distinguish  those  returned by  +cipher
        command  and those from  all other tests and checks like   +check  or
        +info  command.


          The cipher checks will return  one line for each  tested cipher. It
          contains at least the cipher name,  'yes'  or  'no'  whether  it is
          supported or not, and a security qualification. It may look like:
              AES256-SHA       yes    HIGH
              NULL-SHA         no     weak

          Depending on the used  --legacy=*  option the format may differ and
          also contain more information.  For details see  --legacy=*  option

          The text for security qualifications are (mainly) those returned by
          openssl (version 1.0.1): LOW, MEDIUM, HIGH and WEAK.
          The same texts, but with all lower case characters, are used if the
          qualification was adapted herein. Following rules for adjusting the
          qualification were used:

            * weak:
              ** all *NULL* ciphers
              ** all *RC2* and  *RC4*  ciphers
              ** all *EXPORT*  ciphers
              ** all *anon* (aka ADH aka DHA) ciphers
              ** all *CBC* and *CBC3* (aka 3DES) and DES ciphers
            * low:
            * high:
              ** all *AES(128|256)* ciphers
              ** all *CAMELLIA* ciphers


          These tests return a line with  a label  describing the test  and a
          test result for it. The  idea is to report  'yes'  if the result is
          considered "secure"  otherwise report  'no'  followed by the reason
          why it's considered insecure. Example of a check considered secure:
              Label of the performed check:           yes

          Example of a check considered insecure:
              Label of the performed check:           no (reason why)

          Note  that there are tests where the results  appear confusing when
          first viewed, like for www.wi.ld:
              Certificate is valid according given hostname:  no (*.wi.ld)
              Certificate's wildcard does not match hostname: yes

          This can for example occur with:
              Certificate Common Name:                *.wi.ld
              Certificate Subject's Alternate Names:  DNS:www.wi.ld

          Please check the result with the  +info  command also to  verify if
          the check sounds reasonable.


          The test result contains detailed information. The labels there are
          mainly the same as for the  +check  command.


        There are commands for various tests according the  SSL connection to
        the target, the targets certificate and the used ciphers.

        All commands are preceded by a  '+'  to easily distinguish from other
        arguments and options. However, some --OPTIONS options are treated as
        commands for historical reason or compatibility to other programs.

        The most important commands are (in alphabetical order):
          +check +cipher +info +http +list +quick +sni +sni_check +version

        A list of all available commands will be printed with:

        The description of all other commands will be printed with:
 --header --help=commands

        The summary and internal commands return requested information or the
        results of checks. These are described below.

        Note that some commands may be a combination of other commands, see:
 --header --help=intern

        The following sub-sections only describe the commands,  which do more
        than giving a simple information from the target.  All other commands
        can be listed with:
 --header --help=commands

        The final sub-sections  Notes about commands  describes some notes
        about special commands and related commands.

    Commands for information about this tool

        All these commands will exit after execution (cannot be used together
        with other commands).


          Show ciphers offered by local SSL implementation.

          This commands prints the ciphers in a format like "openssl ciphers"
          does. It also accepts the  -v  and  -V  option. The  --legacy=TYPE
          option can be used as described for  +list  command.
          Use  +list  command for more information according ciphers.


          Show all ciphers supported by this tool. This includes cryptogrphic
          details of the cipher and some internal details about the rating.

          In contrast to the  +ciphers  command,  +list  uses  TAB characters
          instead of spaces to seperate columns.  It also prints table header
          lines by default.

          Different output formats are used for the  --legacy  option:
            * --legacy=simple   tabular output of cipher values
            * --legacy=full     as --legacy=simple but more data
            * --legacy=openssl  output like with +ciphers command
            * --legacy=ssltest  output like "ssltest --list"


          Just show version and exit.


          Show version information for both the program and the  Perl modules
          that it uses, then exit.

          Use  --v  option to show more details.


          Show version of openssl.


          Show internal data and exit, used for testing and debugging only.
          Please see  TESTING  below.

    Commands to check SSL details

        Following (summary and internal) commands are simply a shortcut for a
        list of other commands. For details of the list use:


          Check the SSL connection for security issues. Implies  +cipher .


          Print details about the targets hostname, DNS, etc.
          These details are usually printed only for the  +check  and  +info
          command, but not for any individual command.


          Perform HTTP checks (like STS, redirects etc.).


          Overview of most important details of the SSL connection.

          Use  --v  option to show details also, which span multiple lines.


          Overview of all details of the SSL connection. It is a shortcut for
          all commands listed below but not including  +cipher.

          This command is intended for debugging as it prints some details of
          the used "Net::SSLinfo" module.


          Quick overview of checks. Implies  --enabled  and  --label=short.


          Check if servers offers ciphers with prefect forward secrecy (PFS).


          Check for protocols supported by target.


          Check for various vulnerabilities.


          Various checks according STS HTTP header.
          This option implies  --http,  means that  --no-http is ignored.


          Check for Server Name Indication (SNI) usage.


          Check for Server Name Indication (SNI) usage  and  validity  of all
          names (CN, subjectAltName, FQDN, etc.).


          Various checks according BSI TR-02102-2 and TR-03116-4 compliance.


          Various checks according certificate's extended Validation (EV).

          Hint: use option  --v --v  to get information about failed checks.


          Check length, size and count of some values in the certificate.


          Dump data retrieved from  "openssl s_client ..."  call. This should
          be used for debugging only.
          It can be used just like openssl itself, for example:
              openssl s_client -connect host:443 -no_sslv2


          Dumps internal data for SSL connection and target certificate. This
          is mainly for debugging and  should not be used together with other
          commands (except +cipher).
          Each key-value pair is enclosed in  '#{'  and  '#}' .

          Using  --trace --trace  dumps data of "Net::SSLinfo" too.


          Command used internally when requested to use other libraries.
          This command should not be used directly.

    Commands to test ciphers provided by target

          Beside the description of the commands itself here, please see also
          Notes about commands  below.


          Check target for ciphers,  either all ciphers, or ciphers specified
          with  --cipher=CIPHER  option.

          Note that ciphers not supported by the local SSL implementation are
          not checked by default, use  +cipherall or +cipherraw   command.

          Use  --v  option to see all ciphers being checked.


          Check target for all possible ciphers.
          Does not depend on local SSL implementation.

          In contrast to  +cipher  this command has some options to tweak the
          cipher tests, connection results and some strange behaviours of the
          target. See  Options for  cipherall and cipherraw  command  for


          Same as  +cipherraw  but ouput format similar to  +cipher  command.


          Lists the cipher selected by the server for each protocol sometimes
          referred to as "default cipher".

          For each protocol the two selected ciphers are shown,  one returned
          by the server if the cipher list in the  ClientHello is sorted with
          the strongest cipher first, and one returned  if the cipher list in
          the ClientHello is sorted with strongest cipher last.
          See  Notes about commands  for details.


          Checked target for ciphers. All ciphers supported by the server are
          printed with their DH or ECDH paramaters (if available).


          Check if target accepts NULL ciphers.


          Check if target accepts ciphers with anonymous key exchange.


          Check if target accepts EXPORT ciphers.


          Check if target accepts CBC ciphers.


          Check if target accepts DES ciphers.


          Check if target accepts RC4 ciphers.


          Check if target supports ephemeral ciphers.


          Check if target supports ciphers with PFS.


          Check if target selects strongest cipher.


          Check if target selects weak cipher (oposite of  +cipher-strong).

    Discrete commands to test SSL connection and certificate details

        Discrete commands, please see:

    Notes about commands

      +cipher vs. +cipherall

          +cipher  can only check for ciphers - more precise: cipher suites -
          provided by the local SSL implementation (i.e. libssl).
          +cipherall  can check for any cipher,  as it just uses the cipher's
          integer value in the range 0 .. 65532.

      +cipherall vs. +cipherraw

          These commands are identical, just the output format is different.

      +cipher vs. +cipher-dh

          While  +cipher  prints checked ciphers,  +cipher-dh  prints ciphers
          with their DH or ECDH paramaters (if available)  only for supported

      +cipher vs. +cipher-default

          Both commands show the default cipher foreach protocol.

          +cipher  lists a summary of ciphers selected by the server for each
          protocol requested by the user (for example by using options like:
          --sslv3 --tlsv1 etc.).  When the  --v  option is used, all selected
          ciphers for all known protocols are listed. This summary focuses on
          counts for various ciphers.

          +cipher-default  lists the  cipher selected  by the server for each

      +cipher-selected vs. +cipher-default

          +selected  lists the cipher selected by the server if no particular
          protocol was specified and the system's default cipher list is send
          in the ClientHello to the server.

          +cipher-default  lists the  cipher selected  by the server for each

      +cipher-strong vs. +cipher-default

          +strong-cipher  shows the result of the check if strong ciphers are
          preferred by the server. It is a check command.

          +cipher-default  lists the  cipher selected  by the server for each
          protocol. It is a information command.

          It is not possible to check if a server uses 'SSLHonorCipherOrder'.
          Even if it is used (switched on),  it is not possible to  check the
          specified order of the ciphers.

          I. g. it is expected that the order is according the cipher suite's
          strength, meaning the most strongest first, and the weakest last.
          It does not make sense to use an order where a weak cipher preceeds
          a stronger one. Such a (mis-)configuration should be detected.

          Having this in mind, the algorithm to detect a  proper cipher order
          is as simply as follows:
            1. pass sorted cipher list with strongest cipher first
            2. pass sorted cipher list with strongest cipher last
          if the server returns the same cipher for both checks, it's assumed
          that it prefers to use the most strongest cipher. In this case it's
          obvious that 'SSLHonorCipherOrder' is set (exceptions see below).

          +cipherall  uses a  more accurate algorithm  to detect the server's
          cipher order.

          If either, the server or the client,  uses only one cipher suite in
          the list, SSLHonorCipherOrder cannot be detected at all.
          The same happens, if only one cipher in the client's list matches a
          cipher in the server's list.

      +extensions vs. +tlsextensions

          +extensions  shows the "Certificate extensions" and  +tlsextensions
          will show the TLS protocol extensions.
          Use  +tlsextdebug  to show more informations about the TLS protocol

      +http2 +spdy +spdy3 +spdy31 +spdy4 +prots

          These commands are just an alias for the  +protocols  command.

      +hostname vs. +wildhost vs. +altname vs. +rfc_2818

          The commands  +cn  and  +altname  print the  information stored  in
          the certificate.
          The command  +hostname  checks if the given hostname matches the CN
          value in the certificate.  Note that wildcard names in the CN, only
          allow to contain one '*'.
          The command  +wildcard  checks if the given hostname does not match
          any name specified in the certificate's "subjectAltname". This check
          is usefull  if the certificate and the configuration must comply to
          RFC 6125 or EV certificates.


        All options are written in lowercase. Words written in all capital in
        the description here is text provided by the user.

    Options for help and documentation





          Show available commands; short form.


          Show available commands with short description.


          Show available options; short form.


          Show available options with their description.


          Show available checks.


          Description of tools around O-Saft, when, where and how to use.


          Show additional and user specified commands.


          Show additional and user specified commands.  Output can be use in
          RC-FILE  or as option.


          Show texts used as labels in output for checks (see  +check)  ready
          for use in  RC-FILE  or as option.


          Show available informations.


          Show texts used  as labels in output for  data  (see  +info)  ready
          for use in  RC-FILE  or as option.


          Show texts used in hint messages.


          Show texts used in hint messages ready for use in  RC-FILE  or as


          Show texts used in various messages.


          Show texts used in various messages ready for use in  RC-FILE  or
          as option.


          Show possible legacy formats (used as value in  --legacy=TOOL).


          Show available compliance checks.


          Show internal commands.


          Show alias for commands and options.


          Show list of cipher pattern (used for  --cipher=CIPHER).


          Show list of cipherranges (see  --cipherrange=RANGE).


          Show score value for each check.
          Value is printed in format to be used for  --cfg-score=KEY=SCORE.

          Note that the  sequence  of options  is important.  Use the options
          --trace  and/or  --cfg-score=KEY=SCORE  before  --help=score.


          Show headlines from help text. Useful to get an overview.


          Show  'SECTION'  from documentation, see  --help=toc  for a list.


          Show regular expressions to match our own strings used in output.


          Show regular expressions used internally.


          Print documentation in HTML format.


          Print documentation in POD format.


          Print documentation in mediawiki format.


          Print documentation in format to be used for CGI.


          Show  KNOWN PROBLEMS  section with  description of known  error and
          warning messages.


          Show  KNOWN PROBLEMS  and  LIMITATIONS  section.


          Show common abbreviation used in the world of security.


          Show list of URLs related to SSL/TLS.


          Show list of RFC related to SSL/TLS.


          Show known problems and bugs.


          Show possible  --exit=KEY  options. Used for debugging only.


          For developers.

    Options for all commands (general)


          Do DNS lookups to map given hostname to IP, do a reverse lookup.


          Do not make DNS lookups.
          Note  that the corresponding IP and reverse hostname may be missing
          in some messages then.


          Specify HOST as target to be checked. Legacy option.


          Specify PORT of target to be used. Legacy option.

      --host=HOST --port=PORT HOST:PORT HOST

          When giving more than one HOST argument,  the sequence of the given
          HOST argument and the given  --port=PORT  and the given --host=HOST
          options are important.
          The rule how ports and hosts are mapped is as follows:

            HOST:PORT arguments are used as is (connection to HOST on PORT)
            only HOST is given, then previous specified  --port=PORT  is used

          Note that URLs are treated as HOST:PORT, if they contain a port.
     +cmd host-1 --port 23 host-2 host-3:42 host-4

          will connect to:
            * host-1:443
            * host-2:23
            * host-3:42
            * host-4:23

      --proxyhost=PROXYHOST --proxy=PROXYHOST:PROXYPORT

          Make all connection to target using PROXYHOST.

          Also possible is: --proxy=PROXYUSER:PROXYPASS@PROXYHOST:PROXYPORT


          Make all connection to target using PROXYHOST:PROXYPORT.


          Specify username for proxy authentication.


          Specify password for proxy authentication.


          Use 'STARTTLS' command to start a TLS connection via SMTP.
          This option is a shortcut for  --starttls=SMTP .


          Use 'STARTTLS' command to start a TLS connection via protocol.
          'PROT' may be any of:  'SMTP', 'IMAP', 'IMAP2', 'POP3', 'FTPS',
          'RDP', 'LDAP' or 'XMPP' .

          For  --starttls=SMTP  see  --dns-mx  also to use MX records instead
          of host


          Number of seconds to wait before sending a packet, to slow down the
          'STARTTLS' requests. Default is 0.
          This may prevent blocking of requests by the target due to too much
          or too fast connections.
          Note:  In this case there is an automatic suspension and retry with
          a longer delay.


          Internal use for CGI mode only.

    Options for SSL tool


          Read  RC-FILE  if exists, from directory where program was found.


          Do not read  RC-FILE.


          The exit status code will be greater 0, if any of following applies:
          * any check returns  'no'
          * insecure protocols are available
          * insecure ciphers are supported
          * ciphers without PFS are supported (disable with --exitcode-cipher)

          In particular, the status code will be the total count of all these

          Parts of these checks can be diasabled,  see  --exitcode-*  options

          Functionality implemented experimental, may change in future.


          Do not count checks with result 'no' for  --exitcode .

      --exitcode-no-low  --exitcode-no-weak  --exitcode-no-medium

          Do not count LOW, WEAK or MEDIUM security ciphers for  --exitcode .


          Do not count any ciphers for  --exitcode .


          Do not count any ciphers for  --exitcode .


          Do not count ciphers without PFS for  --exitcode .

      --openssl-s_client --s_client

          Use  "openssl s_slient ..."  call to retrieve more information from
          the SSL connection.  This is disabled by default on Windows because
          of performance problems. Without this option (default on Windows !)
          following informations are missing:
              compression, expansion, renegotiation, resumption,
              selfsigned, verify, chain, protocols, DH parameters

          See "Net::SSLinfo" for details.

          If used together with  --trace, s_client  data will also be printed
          in debug output of "Net::SSLinfo".


          Do not use external "openssl"  tool to retrieve information. Use of
          "openssl" is disabled by default on Windows.
          Note that this results in some missing informations, see above.


          'TOOL'        can be a path to openssl executable; default: openssl

      --openssl-cnf=FILE --openssl-conf=FILE

          'FILE'        path of directory or full path of openssl.cnf

          If set, environment variable OPENSSL_CONF will be set to given path
          (or file) when "openssl(1)" is started. Please see openssl's man page
          for details about specifying alternate  openssl.cnf  files.

      --openssl-ciphers --force-openssl

          Use openssl to check for supported ciphers;  default: "IO::Socket(1)"

          This option forces to use  "openssl s_slient -connect CIPHER .." to
          check if a cipher is supported by the remote target. This is useful
          if the  --lib=PATH  option doesn't work (for example due to changes
          of the API or other incompatibilities).


          'PATH'        is a full path where to find openssl.


          'PATH'        is a full path where to find,

          See HACKER's INFO below for a detailed description how it works.


          'NAME'  is the name of a environment variable containing additional
          paths for searching dynamic shared libraries.
          Default is LD_LIBRARY_PATH.

          Check your system for the proper name, i.e.:


          The connection to  a target may fail, or even block, due to various
          reasons for example lost network at all, blocking at firewall, etc.
          In particular when checking ciphers with  +cipher , this may result
          in long delays until results are printed.
          Using this option stops trying to do more connections to the target
          when  --ssl-error-max=CNT  consecutive errors occoured, or when the
          total amount of errors increases  --ssl-error-total=CNT.

          Note that this may result in loss of information and/or checks.


          Max. amount of consecutive errors (default: 5).


          Timeout in seconds when a failed connection is treated as error and
          then counted (default: 1).


          Max. total amount of errors (default: 10).


          I.g. this tools tries to identify available functionality according
          SSL versions from the underlaying libraries.  Unsupported  versions
          are then disables and a warning is shown.
          Unfortunately some libraries have  not implemented all functions to
          check availability of a specific SSL version, which then results in
          a compile error.

          This option disables the strict check of availability.
          If the underlaying library doesn't support the required SSL version
          at all, following error may occour:
              Can't locate auto/Net/SSLeay/ in @INC ...

          See Note on SSL versions  for a general note about SSL versions.
          A more detailled description of the problem and how Net::SSLeay be-
          haves, can be found in the source of ,
          see section starting at
              #| check for supported SSL versions


          Timeout in seconds when connecting to the target (default: 2).


          'METHOD'      method to be used for specific functionality

          Available methods:
          * info-socket         use internal socket to retrieve information
          * info-openssl        use external openssl to retrieve information
          * info-user           use usr_getinfo() to retrieve information
          * cipher-socket       use internal socket to ckeck for ciphers
          * cipher-openssl      use external openssl to ckeck for ciphers
          * cipher-user         use usr_getciphers() to ckeck for ciphers

          Method names starting with:
          * info-
            are responsible to retrieve information  about the SSL connection
            and the target certificate (i.e. what the +info command provides)
          * cipher-
            are responsible to connect to the target  and test if it supports
            the specified ciphers  (i.e. what the  +cipher  command provides)
          * check-
            are responsible for performing the checks (i.e. what's shown with
            the  +check  command)
          * score-
            are responsible to compute  the score based on check results

          The second part of the name denotes which kind of method to call:
          * socket      the internal functionality with sockets is used
          * openssl     the exteranl openssl executable is used
          * user        the external special function, as specified in user's
              ,  is used.


          will use the external "openssl(1)" executable to check the target for
          supported ciphers.

          Default settings are:
              --call=info-socket --call=cipher-socket --call=check-socket

          Just for curiosity, instead of using:
     --call=info-user --call=cipher-user --call=check-user --call=score-user ...

          consider to use your own script like:
              #!/usr/bin/env perl



          Print list of ciphers in style like: "openssl ciphers -v".
          Option used with  +ciphers  command only.


          Print list of ciphers in style like: "openssl ciphers -V".
          Option used with  +ciphers  command only.

    Options for SSL connection to target


          * 'CIPHER'    can be any string accepeted by openssl or following:
          * 'yeast'     use all ciphers from list defined herein, see  +list

          Beside the cipher names accepted by openssl, CIPHER can be the name
          of the constant or the (hex) value as defined in openssl's files.
          Currently supported are the names and constants of openssl 1.0.1k.
            * --cipher=DHE_DSS_WITH_RC4_128_SHA
            * --cipher=0x03000066
            * --cipher=66

          will be mapped to   'DHE-DSS-RC4-SHA'

          Note: if more than one cipher matches, just one will be selected.

          Default is 'ALL:NULL:eNULL:aNULL:LOW' as specified in "Net::SSLinfo".


          TCP socket will be reused for  next connection attempt  even if SSL
          connection failed.


          Close TCP socket and then reopen for next connection attempt if SSL
          connection failed.

          This is useful for some servers which may return an "TLS alert"  if
          the connection fails and then fail again on the same socket.


          A simple check if the target can be connected  will be performed by
          default.  If this check fails, the target will be ignored, means no
          more requested checks will be done.  As this connection check some-
          times fails due to various reasons, the check can be disabled using
          this option.


          Do not use *-MD5 ciphers for other protocols than SSLv2.
          This option is only effective with  +cipher  command.

          The purpose is to avoid warnings from "IO::Socket::SSL(1)" like:
              Use of uninitialized value in subroutine entry at lib/IO/Socket/ line 430.

          which occours with some versions of "IO::Socket::SSL(1)" when a *-MD5
          ciphers will be used with other protocols than SSLv2.

          Note that these ciphers will be checked for SSLv2 only.

      --SSL, -protocol SSL


          * 'SSL'       can be any of:
            ssl, ssl2, ssl3, sslv2, sslv3, tls1, tls1, tls11, tls1.1, tls1-1,
            tlsv1, tlsv11, tlsv1.1, tlsv1-1 (and similar variants for tlsv1.2).
          For example:  --tls1  --tlsv1  --tlsv1_1  are all the same.

          (--SSL variants):    Test ciphers for this SSL/TLS version.
          (--no-SSL variants): Don't test ciphers for this SSL/TLS version.


          Shortcut for:
          --no-sslv2 --no-sslv3 --no-tlsv1 --no-tlsv11 --no-tlsv12 --no-tlsv13


          Shortcut for:  --sslv2 --sslv3 --tlsv1 --tlsv11 --tlsv12 --tlsv13


          Shortcut for:
          --no-dtlsv09 --no-dtlsv1 --no-dtlsv11 --no-dtlsv12 --no-dtlsv13


          Shortcut for:  --dtlsv09 --dtlsv1 --dtlsv11 --dtlsv12 --dtlsv13


          This option  forces  to assume that  SSLv2  is enabled  even if the
          target does not accept any ciphers.

          The target server may accept connections with  SSLv2  but not allow
          any cipher. Some checks verify if  SSLv2  is enabled at all,  which
          then would result in a failed test.
          The default behaviour is to assume that  SSLv2 is not enabled if no
          ciphers are accepted.


          Make a HTTP request if cipher is supported.

          If used twice debugging will be enabled using  environment variable


          Do not make HTTP request.


          Make SSL connection in SNI mode.


          Do not make SSL connection in SNI mode (default: SNI mode).


          Test with and witout SNI mode (+cipherall  only).


          Do not check if SNI seems to be supported by "Net::SSLeay(1)".
          Older versions of openssl and its libries do not support SNI or the
          SNI support is implemented buggy. By default it's checked if SNI is
          properly supported. With this option this check can be disabled.

          Be warned that this may result in improper results.


          If SNI mode is active, see  --sni  above, 'NAME' is used instead of
          hostname for connections to the target.  If SNI mode is not active,
          see  --no-sni  above, 'NAME' is not used. The default is undefined,
          which forces to use the given FQDN.

          This is useful, for example when an IP instead of a FQDN was given,
          where a correct hostname (i.g. a FQDN) needs to be specified.

          Note: i.g. there is no need to use this option,  as a correct value
          for the SNI name will be choosen automatically (except for IPs).
          However, it is kind of fuzzing ... even setting to an  empty string
          is possible.

          Limitation:  the same 'NAME' is used for all targets,  if more than
          one target was specified.


          Do not get data from target's certificate, return empty string.

      --no-cert --no-cert

          Do not get data from  target's certificate,  return  default string
          of "Net::SSLinfo" (see  --no-cert-text=TEXT  option).


          Set 'TEXT' to be returned from "Net::SSLinfo" if no certificate data
          is collected due to use of  --no-cert.


          Check certificate chain to depth 'INT' (like openssl's -verify).


          Use 'FILE' with bundle of CAs to verify target's certificate chain.


          Use 'DIR' where to find CA certificates in PEM format.


          I. g. openssl uses default settings where to find certificate files.
          When  --ca-file=FILE  and/or  --ca-path=DIR  was used,  this default
          will be overwritten by appropriate options passed to openssl. If the
          default does not work as expected,  --force-ca  can be used to force
          setting of proper values according well known common defaults. See:
     +version --force-ca

          to see the used settings.


          Use  -alpn  option for openssl.


          Do not use  -alpn  option for openssl.


          Do not use  -nextprotoneg  option for openssl.


          Name of protocol to be added to list of  applcation layer protocols
          (ALPN), which is used for any connection to the targets.
          See  --cipher-alpn=NAME  also.


          Name of protocol to be added to list of  next protocol negotiations
          (NPN), which is used for any connection to the targets.
          See  --cipher-npn=NAME  also.

      --ssl-compression --compression

          Use SSL option "compression" for connection.

      --no-ssl-compression --no-compression

          Use SSL option "no compression" for connection (default: don't use)


          Do not use  -reconnect  option for openssl.


          Do not use  -tlsextdebug  option for openssl.


          Argument or option passed to openssl's  s_client  command.

    Options for  +cipher  command


          Additional delay in seconds  after each connect for a cipher check.
          This is useful when connecting to servers which have IPS in place,
          or are slow in accepting new connections or requests.


          Name of protocol to be added to list of  applcation layer protocols
          (ALPN), which is used for cipher checks.

          --cipher-alpn=,   sets empty list.
          --cipher-alpn=,,  sets list to empty element "".


          Name of protocol to be added to list of  next protocol negotiations
          (NPN), which is used for cipher checks.

          --cipher-npn=,   sets empty list.
          --cipher-npn=,,  sets list to empty element "".

          Note:  setting empty list or element most likely does not work with
          openssl executable (i.e.  --force-openssl).


          Name of ecliptic curve to be added to list of ecliptic curves (EC),
          which is used for cipher checks.

          --cipher-curve=,   sets empty list.
          --cipher-curve=,,  sets list to empty element "".

          Note:  setting empty list or element most likely does not work with
          openssl executable (i.e.  --force-openssl).

    Options for  cipherall and cipherraw  command


          Specify range of cipher constants to be tested by  +cipherall.
          Following RANGEs are supported:
          * 'rfc'               all ciphers defined in various RFCs
          * 'shifted'           'rfc', shifted by 64 bytes to the right
          * 'long'              like 'rfc' but more lazy list of constants
          * 'huge'              all constants  0x03000000 .. 0x0300FFFF
          * 'safe'              all constants  0x03000000 .. 0x032FFFFF
          * 'full'              all constants  0x03000000 .. 0x03FFFFFF
          * 'SSLv2'             all ciphers according RFC for SSLv2
          * 'SSLv2_long'        more lazy list of constants for SSLv2 ciphers

          Note: 'SSLv2' is the internal list used for testing SSLv2 ciphers.
          It does not make sense to use it for other protocols; however ...


          Additional delay in seconds  after the server is connected  using a
          proxy or before starting 'STARTTLS'.
          This is useful when connecting via  slow proxy chains or connecting
          to slow servers before sending the 'STARTTLS' sequence.


          Maximal number of ciphers sent in a sslhello (default: 32).


          Send SSL extension  'reneg_info'  even if list of ciphers includes
          'TLS_EMPTY_RENEGOTIATION_INFO_SCSV' (default: do not include)


          Some servers do not answer  (i.g. they disconnect) if  none of  the
          offered ciphers is supported by the server.

          Continue testing with next ciphers  when the target  disconnects or
          does not send data within specified timeout (see --timeout).
          Useful for TLS intolerant servers.


          Abort testing with next ciphers when the target disconnects.


          Use supported elliptic curves.  Default on.


          Use TLS 'ec_point_formats' extension.  Default on.


          Test for ciphers with "secure renegotiation" flag set.
          Default: don't set "secure renegotiation" flag.


          Number of retries when connection timed-out (default: 2).


          Number of seconds to wait until connection is qualified as timeout.


          Get DNS MX records for given target and check the returned targets.
          (only useful with  --starttls=SMTP).

    Options for checks and results

        Options used for  +check  command:


          Only print result for ciphers accepted by target.


          Only print result for ciphers not accepted by target.


          Checks are done case insensitive.


          Checks are done case sensitive. Default: case insensitive.
          Currently only checks according CN, alternate names in the target's
          certificate compared to the given hostname are effected.


          When checking for the TLS "heartbeat" extension, the server may not
          respond at all, which would result in a  "no reply"  message.  This
          marks the check for  +heartbleed  as 'no'.
          I.g.  a server is  not vulnerable to the  heartbleed attack  if the
          TLS "heartbeat" extension is disabled. Hence the check result  'no'
          may be mis-leading.  This option  treats the  "no reply"  result as
          "not vulnerable" and returns  'yes'  then.

          Note: if the server does not respond for this check,  does not mean
          that the "heartbeat" extension is switched off.  If unsure, disable
          this lazy check with  --no-ignore-no-reply .

    Options for output format


          Defines the format of the descriptive text (label) for  +check  and
          +info  command.
          Following 'TYPE's are supported:


          Prints full text for labels:

              Certificate Common Name:  some.tld


          Prints short less descriptive text for labels:

              Common Name:              some.tld


          Internal format: print name of key instead of text as label. Key is
          Prints name of key instead of text as label. The key is that of the
          internal data structure(s).

              [cn]                      some.tld

          For ciphers and protocols, the corresponding  hex value  is used as
          key. Note that these values are unique.


          For compatibility with other tools,  the output format used for the
          result of the  +cipher  command can be adjusted to mimic the format
          of other SSL testing tools.

          The argument to the  --legacy=TOOL  option  is the name of the tool
          to be simulated.

          Following TOOLs are supported:
          * 'sslaudit'          format of output similar to  sslaudit
          * 'sslcipher'         format of output similar to  ssl-cipher-check
          * 'ssldiagnos'        format of output similar to  ssldiagnos
          * 'sslscan'           format of output similar to  sslscan
          * 'ssltest'           format of output similar to  ssltest
          * 'ssltestg'          format of output similar to  ssltest -g
          * 'ssltest-g'         format of output similar to  ssltest -g
          * 'sslyze'            format of output similar to  sslyze
          * 'ssl-cipher-check'  same as sslcipher
          * 'ssl-cert-check'    format of output similar to  ssl-cert-check
          * 'testsslserver'     format of output similar to  TestSSLServer.jar
          * 'thcsslcHeck'       format of output similar to  THCSSLCheck

          Note that these legacy formats only apply to  output of the checked
          ciphers. Other texts like headers and footers are adapted slightly.

          Please do not expect identical output as the TOOL  when using these
          options, it's a best guess and should be parsable in a very similar


          Internal format: mainly avoid tabs and spaces format is as follows:
                Some Label:<-- anything right of colon is data


          Internal format: pretty print each label in its own line,  followed
          by data prepended by tab character (useful for  +info  only).


          Results for cipher checks use rating from OWASP Cipher Cheat Sheet.


          Internal format: use tab as separator; ciphers are printed with bit
          length (implies --tab).


          Internal default format.


          This option is used to specify the format of the result lines. This
          covers the value of the result line only.

          * 'raw'       Print raw data as passed from "Net::SSLinfo".
            Note:  all data will be printed as is,  without  additional label
            or formatting. It's recommended to use the  option in conjunction
            with exactly one command.  Otherwise the user needs  to know  how
            to "read"  the printed data.

          * 'hex'       Convert some data to hex: 2 bytes separated by ':'.
          * '0x'        Convert some data with hex values:
                           2 bytes preceded by '0x' and separated by a space.
          * '/x'        Same as  --format=\x
          * '\x'        Convert some data with hex values:
                           2 bytes preceded by '\x' and no separating char.


          Print formatting header.  Default for  +check,  +info,  +quick  and
          and  +cipher  only.


          Do not print formatting header.
          Usefull if raw output should be passed to other programs.

          Note: must be used on command line to inhibit all header lines.


          Do not print output (data or check result) for command 'CMD'. 'CMD'
          is any valid command, see  COMMANDS ,  without leading '+'.
          Option can be used multiple times.


          Print scoring results. Default for  +check.


          Do not print scoring results.


          'CHAR'    will be used as separator between  label and value of the
                    printed results. Default is  ':'.


          'TAB' character (0x09, \t)  will be used as separator between label
          and value of the printed results.
          As label and value are already separated by a  TAB  character, this
          options is only useful in conjunction with the  --legacy=compact


          Prefix each printed line with the given hostname (target).
          The hostname will be followed by the separator character.


          This option is used to specify the general output format for STDOUT
          and STDERR. All results are written to STDOUT,  errors and warnings
          may also be written to STDERR .  The default is ':unix:utf8', which
          is the perlish definition used internally.

          Following values are supported:

          * 'raw'
          * 'unix'      Print raw data, binary in bytes without conversion.
            Note:  binary here just means characters (as all output is text).

          * 'utf8'      Convert all characters to UTF-8.
          * 'crlf'      Use CR LF as end of line.

          * 'CHARSET'   'CHARSET' can be any of the local installed character
                        sets, like UTF-8, UTF-16LE, CP1252, iso-8859-7, etc..
                        This conversion may print its own warnings.

          The option can be used multiple times with different values.
          To reset the  default behaviour, either  'raw'  or  'unix'  must be
          used. Obviously, they must be used first. All other values are used
          Note:  'utf8' just defines the format of the characters, it does no
          further checks on the converted characters. In contrast, 'UTF-8' is
          used as real encoding and does some checks.

          For more details, please see  "perldoc -f binmode" .

          Currently (Jan. 2018), these options must be used before any --help


          Obsolete, please use  --std-format=crlf .

    Options for compatibility with other programs

        Please see other programs for detailed description (if not obvious:).
        Note that often only the long form options are accepted as most short
        form options are ambiguous.
        If other programs use the same option,but with a different behaviour,
        then thes other options are not supported.
        For a list of supported options, please see:


        Following list contains only those options not shown with:


                Tool's Option       (Tool) Option
              * --checks CMD        (  same as  +CMD
              * -h, -h=HOST         (various tools) same as  --host HOST
              * -p, -p=PORT         (various tools) same as  --port PORT
              * -t HOST             (ssldiagnos)    same as  --host HOST
              * --UDP               (ssldiagnos)    same as  --udp
              * --timeout, --grep   (    ignored
              * -r,  -s,  -t,  -x   (    ignored
              * --insecure          (      ignored
              * --nopct --nocolor   (ssldiagnos)    ignored
              * -connect, -H, -u, -url, -U          ignored
              * -noSSL                              same as  --no-SSL
              * -no_SSL                             same as  --no-SSL

        For definition of  'SSL'  see  --SSL  and  --no-SSL  above.

    Options for customization

          For general descriptions please see  CUSTOMIZATION  section below.


          Redefine list of commands. Sets  %cfg{cmd-CMD}  to  LIST.  Commands
          can be written without the leading  '+'.
          If  CMD  is any of the known internal commands, it will be redifned.
          If  CMD  is a unknown command, it will be created.

              --cfg-cmd=sni="sni hostname"
          An example  +preload  can be found in  '' .

          To get a list of commands and their settings, use:

          Main purpose is to reduce list of commands or to print them sorted.


          Redefine value for scoring. Sets  %checks{KEY}{score}  to  'SCORE'.
          Most score values are set to 10 by default. Values '0' .. '100' are

          To get a list of current score settings, use:

          For deatils how scoring works, please see  SCORING  section.

          Use the  --trace-key  option for the  +info  and/or  +check command
          to get the values for  'KEY'.


          Redefine texts used for labels in output. Sets  %data{KEY}{txt}  or
          %checks{KEY}{txt}  to  'TEXT'.

          To get a list of preconfigured labels, use:


          Redefine the security value (i.e. HIGH) in the cipher description.


          Redefine general texts used in output. Sets  %text{KEY}  to  'TEXT'.

          To get a list of preconfigured texts, use:

          Note that \n, \r and \t are replaced by the corresponding character
          when read from RC-FILE.


          Read definitions for  %text{KEY}="my text" from file  'FILE'.


          Redefine texts used for hints. Sets  %cfg{hints}{KEY}  to  'TEXT'.

          To get a list of preconfigured texts, use:


          Set the internal  %cfg  hash.  This options is intended for testing
          and debugging only. Please see  TESTING  below.


          See  Options for SSL tool.


          Execute functions defined in "".


          Options ignored, but stored as is internal in  $cfg{usr-args} .
          These options can be used in "" or "".


          Use experimental functionality.
          Some functionality of this tool is  under development and only used
          when this option is given.

    Options for tracing and debugging


          Do not execute, just show commands (only useful in conjunction with
          using openssl).

      Difference --trace vs. --v

          While  --v  is used to print more data,  --trace  is used to  print
          more information about internal data such as procedure names and/or
          variable names and program flow.



          Print more information about checks.

          Note that this option should be first otherwise some debug messages
          are missing.

          Note that  --v  is different from  -v  (see above).

      --v --v

          Print remotely checked ciphers.

      --v-cipher --cipher-v

          Print remotely checked ciphers.
          In contrast to  --v --v  above,  this just prints the ciphers while
          while being checked, but no other verbose messages.


          Print debugging messages.

      --trace --trace

          Print more debugging messages and pass 'trace=2' to Net::SSLeay and

      --trace --trace --trace

          Print more debugging messages and pass 'trace=3' to Net::SSLeay and

      --trace --trace --trace --trace

          Print processing of all command line arguments.


          Print complete command line first. Used for internal testing.


          Print command line argument processing.


          Trace execution of command processing (those given as  +*).


          Print some internal variable names in output texts (labels).
          Variable names are prefixed to printed line and enclosed in  # .
          Example without --trace-key :
              Certificate Serial Number:          deadbeef

          Example with    --trace-key :
              #serial#          Certificate Serial Number:          deadbeef


          Prints trace output with timestamps. More timestamps are printed if
          used together with  --trace-cmd.


          Alias for  --trace-VALUE  options (see above).

            Trace Option        Alias Option
          * --trace=1           same as  --trace
          * --trace=2           same as  --trace --trace
          * --trace=arg         same as  --trace-arg
          * --trace=cmd         same as  --trace-cmd
          * --trace=key         same as  --trace-key
          * --trace=time        same as  --trace-time


          Use FILE instead of the default  RC-FILE, i.e. ''.


          Print debugging messages for  only, but not any modules.


          Print debugging messages for modules only, but not itself.


          Print formatted list of internal functions with their description.
          Not to be intended in conjunction with any target check.


          Print hint messages (!!Hint:).


          Do not print hint messages (!!Hint:).


          Print warning messages (**WARNING:).


          Do not print warning messages (**WARNING:).


          Terminate  at specified 'KEY'. Please see  TESTING  below.

    Options vs. Commands

        For compatibility with other programs and lazy users,  some arguments
        looking like options are silently taken as commands.  This means that
        --THIS  becomes  +THIS  then. These options are:
          * --help
          * --abbr
          * --todo
          * --chain
          * --default
          * --fingerprint
          * --list
          * --version

        Take care that this behaviour may be removed in future versions as it
        conflicts with those options and commands which actually exist, like:

        --sni  vs.  +sni



        Following strings are treated as a command instead of target names:
          * ciphers
          * s_client
          * version

        A warning will be printed.


        We support following options, which are all identical, for lazy users
        and for compatibility with other programs.

      Option Variants

          * --port PORT
          * --port=PORT

        This applies to most such options,  --port  is just an example.  When
        used in the  RC-FILE, the  --OPTION=VALUE  variant must be used.

      Option Names

        Dash '-', dot '.' and/or underscore '_' in option names are optional,
        all following are the same:
          * --no.dns
          * --no-dns
          * --no_dns
          * --nodns

        This applies to all such options,  --no-dns  is just an example.


        Following syntax is supported also:
     http://some.tld other.tld:3889/some/path?a=b

        Note that only the hostname and the port are used from an URL.

    Options vs. Commands

        See  Options vs. Commands  in  OPTIONS  section above


        All SSL related check performed by the tool will be described here.

    General Checks

        Lookup the IP of the given hostname (FQDN), and then tries to reverse
        resolve the FQDN again.

    SSL Ciphers

        Check which ciphers are supported by target. Please see  RESULTS  for
        details of this check.

    SSL Connection


        Check if "heartbeat" extension is supported by target.


        Check if target is vulnerable to POODLE attack (SSLv3 enabled).


        Check if target is vulnerable to ROBOT attack (server offers ciphers
        with RSA encryption).


        Check if target is vulnerable to SLOTH attack  (server offers RSA-MD5
        or ECDSA-MD5 ciphers).


        Check if target is vulnerable to Sweet32 attack (server offers CBC or
        CBC3 or DES or 3DES ciphers).

        Note that FIPS-140 compliance requires 3DES ciphers, hence compliant
        systems are then vulnerable to Sweet32 attacks.


        Check if target supports ALPN. Following messages are evaluated:
              ALPN protocol: h2-14
              No ALPN negotiated

        Please see also  CHECKS  ALPN and NPN  below.

    SSL Vulnerabilities


        Check if ciphers for anonymous key exchange are supported: ADH|DHA.
        Such key exchanges can be sniffed.


        Check if ephemeral ciphers are supported: DHE|EDH.
        They are necessary to support Perfect Forward Secrecy (PFS).


        Check if ciphers with CBC for protocol SSLv1, SSLv3 or TLSv1 are used.
        TLSv1.2 checks are not yet implemented.


        Connection is vulnerable if target supports SSL-level compression, or
        supports SPDY/3 (because SPDY/3 uses compression).

        Note: SPDY/3 is only possible if the client explicitely asks for this
        alternate protocol (for example  "openssl ... -nextprotoneg spdy/3").


        Connection is vulnerable if target supports SSLv2.


        Attack against SSL/TLS to downgrade to EXPORT ciphers.
        Currently (2018) a simple check is used:   SSLv3 enabled and EXPORT
        ciphers supported by server.
        See CVE-2015-0204 and .


        Check if target is vulnerable to heartbleed attack, see CVE-2014-0160
        and .


        Not implemented.

        There are no checks for the HEIST attack implemented, because this is
        an attack on TCP/IP rather than SSL/TLS on top of TCP/IP.


        To perform a MiTM attack with Key Compromise Impersonation, the atta-
        cker needs to engage the victim to install and use a client certificate.
        This is considered a low risk and hence not tested here.


        Check if target is vulenerable to Logjam attack.
        Check if target suports  EXPORT ciphers  and/or  DH Parameter is less
        than 2048 bits. ECDH must be greater to 511 bits.


        Check if CBC ciphers are offered.
        NOTE the recommendation  to be safe against  Lucky13  was to use  RC4
        ciphers. But they are also subject to attacks (see below).  Hence the
        check is only for CBC ciphers.


        Check if RC4 ciphers are supported.
        They are assumed to be broken.
        Note that  +rc4  reports the vulnerabilitiy to the  RC4 Attack, while
        +cipher-rc4  simply reports if  RC4 ciphers are offered.  However the
        check, and hence the result, is the same.


        Check if DHE ciphers are used.  Checks also if the TLS session ticket
        is random or not used at all.
        TLSv1.2 checks are not yet implemented.


        Check if target is vulnerable to  POODLE attack (just check if  SSLv3
        is enabled).

      Practical Invalid Curve Attack

        This attack allows an attacker to read the servers private key if the
        server does not check properly the passed points for a ecliptic curve
        when EDH ciphers are used.

        This check will not send multiple invalid points,  but only checks if
        the server closes the connection or responds with no matching cipher.


        Bleichebacher's Oracle attack against SSL/TLS ciphers.

        Not implemented.


        Currently (2016) we check for ciphers with  ECDSA, RSA-MD5.
        Checking the TLS extension 'tls-unique' is not yet implemented.


        Currently (2016) we check for ciphers with CBC or CBC3 or DES or 3DES.


        Check if target is vulnerable to ticketbleed, means that it returns
        up to 31 random bytes from memory as Session Ticket, see CVE-2016-9244
        and .

    Target (server) Configuration and Support

      SLOTH, Sweet32

        See above.


        Check if the server allows client-side initiated renegotiation.

      Version rollback attacks

        Check if the server allows changing the protocol.

      DH Parameter

        Check if target's DH Parameter is less 512 or 2048 bits.

    Target (server) Certificate

      Certificate Hashes

        Check that fingerprint is not MD5.
        Check that certificate private key signature is SHA2 or better.

      Root CA

        Provided certificate by target should not be a Root CA.

      Self-signed Certificate

        Certificate should not be self-signed.

      FQDN is listed in subjectAltname (RFC2818)

        The FQDN must be listed in the certificates subjectAltname.
        The check command  +rfc_2818_names  is based on the info command
        +verify_hostname . The check was added in 05/2017 because browsers
        started to complain if the FQDN is not part of the subjectAltname.

      IP in CommonName or subjectAltname (RFC6125)


      Basic Constraints

        Certificate extension Basic Constraints should be CA:FALSE.

      OCSP, CRL, CPS

        Certificate should contain URL for OCSP and CRL.

      Private Key encyption

        Certificates signature key supports encryption.

      Private Key encyption well known

        Certificates signature key encryption algorithm is well known.

      Public Key encyption

        Certificates public key supports encryption.

      Public Key encyption well known

        Certificates public key encryption algorithm is well known.

      Public Key Modulus size

        Some (historic) SSL implementations are subject to buffer overflow if

      Public Key Modulus Exponent size

        The modulus exponent should be = 65537 as it is a prime number and an
        easy to calculate exponent.
        If the exponent is less than 65537, "Boradcast" attacks are possible.

        However, some (mainly historic) SSL implementations may have problems
        to connect because they are not able to do the crypt mathematics with
        exponenents larger than 65536.

        If ecliptive curves are used, the result for these checks is always
        'no (<<N/A ...)'.

      Sizes and Lengths of Certificate Settings

        Serial Number <= 20 octets (RFC5280,  Serial Number)


      DV-SSL - Domain Validation Certificate

        The Certificate must provide:
          * Common Name '/CN=' field
          * Common Name '/CN=' in 'subject' or 'subjectAltname' field
          * Domain name in 'commonName' or 'altname' field

      EV-SSL - Extended Validation Certificate

        This check is performed according the requirements defined by the CA/
        Browser Forum .
        The certificate must provide:
          * DV - Domain Validation Certificate (see above)
          * Organization name '/O=' or 'subject' field
          * Organization name must be less to 64 characters
          * Business Category '/businessCategory=' in 'subject' field
          * Registration Number '/serialNumber=' in 'subject' field
          * Address of Place of Business in 'subject' field

        Required are: '/C=', '/ST=', '/L='

        Optional are: '/street=', '/postalCode='

          * Validation period does not exceed 27 month

        See  LIMITATIONS  also.

    Target (server) HTTP(S) Support

      STS header (see RFC 6797)

        Using STS is no perfect security.  While the very first request using
        http: is always prone to a MiTM attack, MiTM is possible to following
        requests again, if STS is not well implemented on the server.
          * Request with http: should be redirected to https:
          * Redirects should use status code 301 (even others will work)
          * Redirect's Location header must contain schema https:
          * Redirect's Location header must redirect to same FQDN
          * Redirect may use Refresh instead of Location header (not RFC6797)
          * Redirects from HTTP must not contain STS header
          * Answer from redirected page (HTTPS) must contain STS header
          * Answer from redirected page for IP must not contain STS header
          * STS header must contain includeSubDirectoy directive
          * STS header max-age should be less than 1 month
          * STS must not be set in http-equiv attribute of a meta TAG

      STS header preload attribute (+preload)

        To satisfy the requirements on  the
        HSTS header must:
          * have the max-age with at least 18 weeks (10886400 seconds)
          * have the includeSubDomains attribute
          * have the preload attribute
          * redirect to https first, then to sub-domains (if redirected)
          * have an HSTS header in each redirect to https.

        Additionally, the site must have:
          * a valid certificate
          * serve all subdomains over https.

        Except the last requirement,  +preload  will do the checks.
        Note that  +preload  is defined in  ''  only.

      Public Key Pins header
        TBD - to be described ...


        Mainly in the certificate various counts, lengths and sizes of values
        are checked and reported. All commands for these checks start with
        '+cnt_'  or  '+len_'.  Up to now, there is no  'yes'  or  'no'  value
        for these checks.

        Following commands will check the value to be in  a specific range to
        become  'yes'  or  'no':
          * +sts_maxage1d       - yes if HSTS maxage < 1 day
          * +sts_maxage1m       - yes if HSTS maxage < 1 month
          * +sts_maxage1y       - yes if HSTS maxage < 1 year
          * +sts_maxage18       - yes if HSTS maxage < 18 weeks (5 months)
          * +sts_maxagexy       - yes if HSTS maxage > 1 year
          * +modulus_exp_1      - Public Key Modulus Exponent <>1
          * +modulus_exp_65537  - Public Key Modulus Exponent =65537
          * +modulus_exp_oldssl - Public Key Modulus Exponent <65537
          * +modulus_size_oldssl - Public Key Modulus <16385 bits

        For some details of these cjecks, please see the description above at
          Public Key Modulus Exponent size

        The recommendations for  DH parameters (RSA and ecliptice curve)  are
        are checked as follows:
          * +dh_512             - DH Parameter >= 512 bits
          * +dh_2048            - DH Parameter >= 2048 bits
          * +ecdh_256           - DH Parameter >= 256 bits (ECDH)
          * +ecdh_512           - DH Parameter >= 512 bits (ECDH)
        Note that only one of the checks  '+dh_*'  and  '+ecdh_*'  can return

    ALPN and NPN

        The commands for the checks to report  'yes'  or  'no', are  +hasalpn
        and  +hasnpn.

        Both, the Application Layer Protocol Negotiation (ALPN) and the  Next
        Protocol Negotiation (NPN) will be tested. The commands for that are:
          * +alpns
          * +npns

        Each, ALPN and NPN, is tested separately with all known protocols.
        The test sets only one protocol,  tries to make a connection and then
        checks if the protocol was accepted by the server. The collected list
        of protocols will be printed with the aforementioned commands, or the
        +info  command. Note the difference for the commands  +next_protocols
        and  +alpns, where  +next_protocols  simply reports  what  the server
        itself advertises, while  +alpns  reports what the server supports if
        asked for.


        Note that it is not possible to satisfy all following compliances.
        Best match is: 'PSF' and 'ISM' and 'PCI' and 'lazy BSI TR-02102-2'.
        In general it is difficult to satisfy all conditions of a compliance,
        and it is also difficult to check  all these conditions.  That is why
        some compliance checks are not completely implemented.
        For details see below please.

        Also note that in the  RC-FILE  the output of results for some checks
        is disabled by default. A  '!!Hint:'  message will be printed, if any
        of these checks are used.

          * FIPS-140
          * ISM
          * PCI
          * BSI TR-02102-2 (2016-01)
          * BSI TR-03116-4
          * RFC 2818
          * RFC 6125
          * RFC 6797
          * RFC 7525

      BSI TR-02102-2 (+tr-02102+ +tr-02102- +bsi)
        Checks if connection and ciphers are compliant according TR-02102-2,

        (following headlines are taken from TR-02102-2 Version 2016-01)

        3.1.3 Schlüssellängen bei EC-Verfahren
die EC-Verfahren ...  und weitere Erläuterungen siehe Bemerkung 4 in Kapitel 3 in [TR-02102-1] .

        3.2   SSL/TLS_Versionen

          Only TLSv1.2 allowed (except for +tr-02102-  which also allows

        3.3.1 Empfohlene Cipher Suites

          Allows only *DHE-*-SHA256, *DHE-*-SHA384, *DH-*-SHA256 and
          *DH-*-SHA384 ciphers and PSK ciphers with ephermeral keys.
          For  +tr-02102+  they must be AES-GCM,  +tr02102- also allows

        3.3.2 Übergangsregelungen

          SHA1 temporary allowed. SHA256 and SHA384 recommended.
          RC4 not reocmmended.
          Use of SHA1 will only be checked for  +tr-02102+

        3.4.1 Session Renegotation

          Only server-side (secure) renegotiation allowed (see RFC 5746).

        3.4.2 Verkürzung der HMAC-Ausgabe

          Truncated HMAC according RFC 6066 not recommended.

        3.4.3 TLS-Kompression und der CRIME-Angriff

          No TLS compression.

        3.4.4 Der Lucky13-Angriff
        3.4.5 Die "Encrypt-then-MAC"-Erweiterung

          Use of AES-GCM ciphers only.
          Use of Encrypt-then-MAC according RFC 7366 cannot be checked.

        3.4.6 Die Heartbeat-Erweiterung

          Target must not support the heartbeat extension.

        3.4.7 Die Extended Master Secret Extension

          Use of Extended Master Secret Extension according RFC 7627 cannot
          be checked.

        3.5 Authentisierung der Kommunikationspartner

          Not checked as only applicable for VPN connections.

        3.6 Domainparameter und Schlüssellängen

          Check if signature key is > 2048 bits.

        3.6.1 Verwendung von elliptischen Kurven


          Use only following curves according RFC 5639 and RFC 7027:
          brainpoolP256r1, brainpoolP384r1, brainpoolP512r1

          Use of secp256r1 and secp384r1  temporary allowed.

        4.1 Schlüsselspeicherung

          This requirement is not testable from remote.

        4.2 Umgang mit Ephemeralschlüsseln

          This requirement is not testable from remote.

        4.3 Zufallszahlen

          This requirement is not testable from remote.

      BSI TR-03116-4 (+tr-03116+ +tr-03116- +bsi)
        Checks if connection and ciphers are compliant according TR-03116-4,

        (following headlines are taken from there)

        2.1.1 TLS-Versionen und Sessions

          Allows only TLS 1.2.

        2.1.2 Cipher Suites

          Cipher suites must be ECDHE-ECDSA or -RSA with AES128 and SHA265.
          For curiosity, stronger cipher suites with AES256 and/or SHA384 are
          not not allowed. To follow this curiosity the  +tr-03116-  (lazy)
          check allows the stronger cipher suites ;-)

        2.1.1 TLS-Versionen und Sessions

          The TLS session lifetime must not exceed 2 days. Encrypt-then-MAC-Extension OCSP-Stapling

          MUST have 'OCSP Stapling URL'.

        4.1.1 Zertifizierungsstellen/Vertrauensanker

          Certificate must provide all root CAs. (NOT YET IMPLEMENTED).

          Should use a small certificate trust chain.

        4.1.2 Zertifikate

          Must have 'CRLDistributionPoint' or 'AuthorityInfoAccess'.

          End-user certificate must not be valid longer than 3 years.
          Root-CA certificate must not be valid longer than 5 years.

          Certificate extension 'pathLenConstraint' must exist, and should be
          a small value ("small" is not defined).

          All certificates must contain the extension 'KeyUsage'.

          Wildcards for 'CN' or 'Subject' or 'SubjectAltName' are not allowed
          in any certificate.

          EV certificates are recommended (NOT YET checked properly).

        4.1.3 Zertifikatsverifikation

          Must verify all certificates in the chain down to their root-CA.

          Certificate must be valid according issue and expire date.

          All Checks must be doen for all certificates in the chain.

        4.1.4 Domainparameter und Schlüssellängen

          This requirement is not testable from remote.

        4 5.2 Zufallszahlen

          This requirement is not testable from remote.

      RFC 2818 (+rfc2818)
        Check if the FQDN is listed in the certificates 'subjectAltname'.

      RFC 6125 (+rfc6125)
        Checks values 'CommonName', 'Subject' and 'SubjectAltname'  of the
        certificate for:
           * must all be valid characters for DNS
           * must not contain more than one wildcard
           * must not contain invalid wildcards
           * must not contain invalid IDN characters

      RFC 6797 (+rfc6797)
        Same as STS header  +hsts .

      RFC 7525 (+rfc7525)
        Checks if connection and ciphers are compliant according RFC 7525.
        (following headlines are taken from there)

        3.1.1.  SSL/TLS Protocol Versions

          SSLv2 and SSLv3 must not be supportetd.
          TLSv1 should only be supported if there is no TLSv1.1 or TLSv1.2.
          Either TLSv1.1 or TLSv1.2 must be supported, prefered is TLSv1.2.

        3.1.2.  DTLS Protocol Versions

          DTLSv1 and DTLSv1.1 must not be supported.

        3.1.3.  Fallback to Lower Versions

          (check implecitely done by 3.1.1, see above)

        3.2.  Strict TLS

          Check if server provides Strict Transport Security.

        3.3.  Compression

          Compression on TLS must not be supported.

        3.4.  TLS Session Resumption

          Server must support resumtion and random session tickets.
          (Randomnes of session tickets implemented YET experimental.)

          Check if ticket is authenticated and encrypted NOT YET IMPLEMENTED.

        3.5.  TLS Renegotiation

          Server must support renegotiation.

        3.6.  Server Name Indication

          (Check for SNI support implemented experimental.)

        4.  Recommendations: Cipher Suites

        4.1.  General Guidelines
        4.2.  Recommended Cipher Suites

          Check for recommended ciphers.

        4.3.  Public Key Length

          DH parameter must be at least 256 bits or 2048 bits with EC.
          (Check currently, 4/2016, based on openssl which may not provide DH
           parameters for all ciphers.)

        4.5.  Truncated HMAC

          TLS extension "truncated hmac" must not be used.

        6.  Security Considerations
        6.1.  Host Name Validation

          Given hostname must matches hostname in certificate's subject.

        6.2.  AES-GCM
        6.3.  Forward Secrecy
        6.4.  Diffie-Hellman Exponent Reuse

        6.5.  Certificate Revocation

          OCSP and CRL Distrbution Point in cetificate must be defined.


        All output is designed to make it  easily parsable by postprocessors.
        Following rules are used:
          * Lines for formatting or header lines start with  '='.
          * Lines for verbosity or tracing start with  '#'.
          * Errors and warnings start with  '**'.
          * Empty lines are comments ;-)
          * Label texts end with a separation character; default is  ':'.
          * Label and value for all checks are separated by at least one  TAB
          * Texts for additional information are enclosed in '<<'  and  '>>'.
          * 'N/A'  is used when no proper informations was found or provided.
            Replace  'N/A'  by whatever you think is adequate:  "No answer",
            "Not available",  "Not applicable",  ...

        Lines not described above, will have the form (by default):
              Label for information or check:  TABresult

        For more details on these lines, please refer to  RESULTS  above.

        When used in  --legacy=full  or --legacy=simple  mode, the output may
        contain formatting lines for better (human) readability.

    Postprocessing Output

        It is recommended to use the   --legacy=quick   option, if the output
        should be postprocessed, as it omits the default separation character
        (':' , see above) and just uses on single tab character (0x09, \t  or
        TAB) to separate the label text from the text of the result. Example:
              Label of the performed checkTABresult

        More examples for postprocessing the output can be found here:


        This tools can be customized as follows:

        * Using command line options

            This is a simple way to redefine  specific settings.  Please  see
            CONFIGURATION OPTIONS  below.

        * Using Configuration file

            A configuration file can contain multiple configuration settings.
            Syntax is simply  KEY=VALUE. Please see CONFIGURATION FILE below.

        * Using resource files

            A resource file can contain multiple command line options. Syntax
            is the same as for command line options iteself.  Each  directory
            may contain its own resource file. Please see  RC-FILE  below.

        * Using debugging files

            These files are - nomen est omen - used for debugging purposes.
            However, they can be (mis-)used to redefine all settings too.
            Please see  DEBUG-FILE  below.

        * Using user specified code

            This file contains  user specified  program code.  It can also be
            (mis-)used to redefine all settings. Please see USER-FILE  below.

        Customization is done by redefining values in internal data structure
        which are:  %cfg,  %data,  %checks,  %text,  %scores.

        Unless used in  DEBUG-FILE  or  USER-FILE,  there is  no need to know
        these internal data structures or the names of variables; the options
        will set the  proper values.  The key names being part of the option,
        are printed in output with the  --trace-key  option.

        I.g. texts (values) of keys in  %data are those used in output of the
        "Information" section. Texts of keys in  %checks  are used for output
        in "Performed Checks" section.  And texts of keys in  %text  are used
        for additional information lines or texts (mainly beginning with '=').

     Configuration File vs. RC-FILE vs. DEBUG-FILE


            Configuration files must be specified with one of the  --cfg-*
            options. The specified file can be a valid path. Please note that
            only the characters:  a-zA-Z_0-9,.\/()-  are allowed as pathname.
            Syntax in configuration file is:  'KEY=VALUE'  where 'KEY' is any
            key as used in internal data structure.

        * RC-FILE

            Resource files are searched for and used automatically.
            For details see  RC-FILE  below.

        * DEBUG-FILE

            Debug files are searched for and used automatically.
            For details see  DEBUG-FILE  below.

        * USER-FILE

            The user program file is included only  if the  --usr  option was
            used. For details see  USER-FILE  below.


        Configuration options are used to redefine  texts and labels or score
        settings used in output. The options are:
          * --cfg-cmd=CMD=LIST
          * --cfg-checks=KEY=TEXT
          * --cfg-data=KEY=TEXT
          * --cfg-hint=KEY=TEXT
          * --cfg-text=KEY=TEXT
          * --cfg-cipher=CIPHER=TEXT

        'KEY'  is the key used in the internal data structure, and  'TEXT' is
        the value to be set for this key.  Note that unknown keys are ignored

        If KEY=TEXT is an exiting filename, all lines from that file are read
        and set. For details see  CONFIGURATION FILE  below.

        CIPHER  must be a valid cipher suite name as shown with:


        NOTE that such configuration options should be used before any --help
        or  --help=*  option, otherwise the changed setting is not visible.


        Note that the file can contain 'KEY=TEXT' pairs for any kind of the
        configuration as given by the  --cfg-CFG  option.

        For example  when used with  --cfg-text=FILE  only values for  %text
        will be set, when used with  --cfg-data=FILE  only values for  %data
        will be set, and so on. 'KEY' will not be used when 'KEY=TEXT' is an
        existing filename. It i recommended to use a non-existing key, i.e.:
        --cfg-text=my_file=some/path/to/private/file .


        The rc-file will be searched for in the working directory only.

        The name of the rc-file is the name of the program file prefixed by a
        '.'  (dot),  for example:  ''.

        A  rc-file  can contain any of the commands and options valid for the
        tool itself. The syntax for them is the same as on command line. Each
        command or option must be in a single line. Any empty or comment line
        will be ignored. Comment lines start with  '#'  or  '='.

        Note that options with arguments must be used as  'KEY=VALUE' instead
        of  'KEY VALUE'.

        Configurations options must be written like '--cfg-CFG=KEY=VALUE'.
        Where 'CFG' is any of:  'cmd', 'check', 'data', 'text'  and  'KEY' is
        any key from internal data structure (see above).

        All commands and options given on command line will  overwrite  those
        found in the rc-file.


        All debugging functionality is defined in "" , which will
        be searched for using paths available in  '@INC'  variable.

        Syntax in this file is perl code.  For details see  DEBUG  below.


        All user functionality is defined in  "" ,  which will be
        searched for using paths available in  '@INC'  variable.

        Syntax in this file is perl code.

        All functions defined in  ""  are called when the option
        --usr  was given.  The functions are defined as empty stub,  any code
        can be inserted as need.  Please see   perldoc ""  to see
        when and how these functions are called.


        Configuring the shell environment where the tool is startet,  must be
        done before the tools starts.  It is  not really  a task for the tool
        itself, but it can simplify your life, somehow.

        There exist customizations for some commonly used shells,  please see
        the files in the ./contrib/ directory.


        The option  --cfg-cmd=CMD=LIST  can be used to define own commands.
        When configuring own commands,  CMD  must not be  one of the commands
        listed with  --help=intern  and CMD  must constist only of digits and

        Examples in  ''  are  +preload  and  +ciphercheck .


        While the SSL/TLS protocol uses integer numbers to identify  ciphers,
        almost all tools use some kind of  "human readable"  texts for cipher

        These numbers (which are most likely written  as hex values in source
        code and documentations) are the only true identifier, and we have to
        rely on the tools that they use the proper integers.

        As such integer or hex numbers are difficult to handle by humans,  we
        decided to use human readable texts. Unfortunately no common standard
        exists how to construct the names and map them to the correct number.
        Some, but by far not all, oddities are described in  Name Rodeo.

        The rules for specifying cipher names are:
          1) textual names as defined by IANA (see [IANA])
          2) mapping of names and numbers as defined by IANA (see [IANA])
          3) '-'  and  '_'  are treated the same
          4) abbreviations are allowed, as long as they are unique
          5) beside IANA, openssl's cipher names are preferred
          6) name variants are supported, as long as they are unique
          7) hex numbers can be used

        [IANA] September 2013

        [openssl] ... openssl 1.0.1

        If in any doubt, use  +list --v  to get an idea about the mapping.
        Use  --help=regex  to see which regex are used to handle all variants

        Mind the traps and dragons with cipher names and what number they are
        actually mapped to. In particular when  --lib,  --exe  or  --openssl
        options are in use. Always use these options with  +list command too.

    Name Rodeo

        As said above, the  SSL/TLS protocol uses integer numbers to identify
        ciphers, but almost all tools use some kind of  human readable  texts
        for cipher names.

        For example the cipher commonly known as 'DES-CBC3-SHA' is identified
        by '0x020701c0' (in openssl) and has 'SSL2_DES_192_EDE3_CBC_WITH_SHA'
        as constant name. A definition is missing in IANA, but there is
        'TLS_RSA_WITH_3DES_EDE_CBC_SHA'.  Thers is also '0x000A' for the same
        cipher 'DES-CBC3-SHA'.  Both are valid, first one if used with SSLv2,
        and second one when used with SSLv3.
        It's the responsibility of each tool to map the human readable cipher
        name to the correct (hex, integer) identifier.

        For example Firefox uses  'dhe_dss_des_ede3_sha',  which is what?

        Furthermore, there are different acronyms for the same thing in use.
        For example  'DHE'  and  'EDH'  both mean "Ephemeral Diffie-Hellman".
        Comments in the "openssl(1)" sources mention this.  And for curiosity
        these sources use both in cypher names, but allow  'EDH'  as shortcut
        only in openssl's "ciphers"  command. Wonder about (up to 1.0.1h):
              openssl ciphers -V EDH
              openssl ciphers -V DHE
              openssl ciphers -V EECDH
              openssl ciphers -V ECDHE

        Next example is  'ADH'  which is also known as  'DH_anon' or 'DHAnon'
        or  'DHA'  or  'ANON_DH'.

        You think this is enough? Then have a look how many acronyms are used
        for  "Tripple DES".

        Compared to above, the interchangeable use of  '-'  vs.  '_' in human
        readable cipher names is just a very simple one. However, see openssl
        again what following means (returns):
              openssl ciphers -v RC4-MD5
              openssl ciphers -v RC4+MD5
              openssl ciphers -v RC4:-MD5
              openssl ciphers -v RC4:!MD5
              openssl ciphers -v RC4!MD5

        Looking at all these oddities, it would be nice to have a common unique
        naming scheme for cipher names. We have not.  As the SSL/TLS protocol
        just uses a number, it would be natural to use the number as uniq key
        for all cipher names, at least as key in our internal sources.

        Unfortunately, the assignment of ciphers to numbers  changed over the
        years, which means that the same number refers to a  different cipher
        depending on the standard, and/or tool, or version of a tool you use.

        As a result, we cannot use human readable cipher names as  identifier
        (aka unique key), as there are  to many aliases  for the same cipher.
        And also the number  cannot be used  as unique key, as a key may have
        multiple ciphers assigned.

        The default behaviour will be to use the cipher names like "openssl(1)"
        does. If a name is ambigous, the first matching will be choosen. This
        -first matching- only applies to names provided by the user by option
        or whatever, internally the latest IANA number will be used,  because
        they have the most less ambiguities.


        This section describes knwon problems, and known error messages which
        may occour when using This sections can be used as FAQ too
        as it gives hints and workarounds.

    Segmentation fault

        Sometimes  the program terminates with a  'Segmentation fault'.  This
        mainly happens if the target does not return certificate information.
        If so, the  --no-cert  option may help.

    **WARNING: empty result from openssl; ignored at ...

        This most likely occurs when the  provided cipher is  not accepted by
        the server, or the server expects client certificates.

    **WARNING: unknown result from openssl; ignored at ...

        This most likely occurs when the "openssl(1)" executable is used with a
        very slow connection. Typically the reason is a connection timeout.
        Try to use  --timeout=SEC  option.
        To get more information, use  --v --v  and/or  --trace  also.

    **WARNING: undefined cipher description

        May occour if ciphers are checked, but no description is available for
        them herein. This results in printed cipher checks like:
              EXP-KRB5-RC4-MD5                no       <<undef>>

        instead of:
              EXP-KRB5-RC4-MD5                no       weak

    **WARNING: Can't make a connection to your.tld:443; no initial data
    **WARNING: Can't make a connection to your.tld:443; target ignored

        This message occours if the underlaying  SSL library (i.e. libssl.a)
        was not able to connect to the target. Known observed reasons are:
          * target does not support SSL protocol on specified port
          * target expects a client certificate in ClientHello message

        More details why the connection failed can be seen using  --trace=2 .

        If the targets supports SSL, it should be at least possible to check
        for supported ciphers using  +cipherall  instead of  +cipher .

    Use of uninitialized value $headers in split ...

        The warning message (like follows or similar):

              Use of uninitialized value $headers in split at blib/lib/Net/
              (autosplit into blib/lib/auto/Net/SSLeay/ line 1290.

        occurs if the target refused a connection on port 80.
        This is considered a bug in "Net::SSLeay(1)".
        Workaround to get rid of this message: use  --no-http  option.

    invalid SSL_version specified at ... IO/Socket/

        This error may occur on systems where a specific  SSL version is not
        supported. Subject are mainly  SSLv2, SSLv3 TLSv1.3 and DTLSv1.
        For DTLSv1 the full message looks like:
              invalid SSL_version specified at C:/programs/perl/perl/vendor/lib/IO/Socket/SSL.

        See also  Note on SSL versions .

        Workaround: use option: --no-sslv2 --no-sslv3 --no-tlsv13 --no-dtlsv1

    Use of uninitialized value $_[0] in length at (eval 4) line 1.

        This warning occours with IO::Socket::SSL 1.967, reason is unknown.
        It seems not to harm functionality, hence no workaround, just ignore.

    Use of uninitialized value in subroutine entry at lib/IO/Socket/ line 430.

        Some versions of  IO::Socket::SSL return this error message if  *-MD5
        ciphers are used with other protocols than SSLv2.

        Workaround: use  --no-md5-cipher  option.

    Can't locate auto/Net/SSLeay/ in @INC ...

        Underlaying library doesn't support the required SSL version.
        See also  Note on SSL versions .

        Workaround: use  --ssl-lazy option, or corresponding --no-SSL option.

    Read error: Connection reset by peer (,199725) at blib/lib/Net/\
    (autosplit into blib/lib/auto/Net/SSLeay/ line 535.

        Error reported by some Net::SSLeay versions. Reason may be a timeout.
        This error cannot be omitted or handled properly.

        Workaround: try to use same call again (no guarantee, unfortunatelly)

    Odd number of elements in anonymous hash at Net/ line 1613.

        This warning from perl have been observed  when the connection to the
        target to check for supported ciphers cannot be established.

        This message can be ignored.

    openssl: ...some/path.../ no version information available (required by openssl)

        Mismatch of  openssl executable  and loaded underlaying library. This
        most likely happens when options  --lib=PATH  and/or  --exe=PATH  are
        used.  See also  Note on SSL versions .

        Hint: use following commands to get information about used libraries:
     --v --v +version

    Integer overflow in hexadecimal number at ...

        This error message may occour on  32-bit systems if perl was not com-
        piled with proper options. I.g. perl automatically converts the value
        to a floating pont number.
        Please report a bug with output of following command:
     +s_client +dump your.tld

    openssl did not return DH Paramter>>

        Text may be part of a value. This means that all checks according  DH
        parameters and logkam attack cannot be done.

        Workaround: try to use  --openssl=TOOL  option.

        This text may appears in any of the compliance checks (like +rfc7525)
        which may be a false positive.  For these checks openssl is also used
        to get the DH Parameter.

        Workaround: not available yet

    No output with  +help  and/or  --help=todo

        On some (mainly Windows-based) systems using

        does not print anything.

        Workaround: use  --v  option.
     +help --v

     +help | more

    Character set (like UTF-8) not recognized in some tools

        Some tools do not diplay all characters properly,  i.e. some versions
        of podviewer. It is not the obligation of this tool to fix well known
        bugs in other tools. However, we can offer workarounds.

        Workaround: generate the affected output using --std-format=* options
        For example:
     --no-rc --std-format=raw --help=gen-pod

    **WARNING: on MSWin32 additional option  --v  required, sometimes ...

        On some (mainly Windows-based) systems  this may happen  when calling
        for example:

        which then may produce:
              **WARNING: on MSWin32 additional option  --v  required, sometimes ...
              === reading: ./ (RC-FILE done) ===
              === reading: Net/ (O-Saft module done) ===
              **USAGE: no command given
              # most common usage:
       +info   your.tld
       +check  your.tld
       +cipher your.tld
              # for more help use:

        Workaround: use full path to perl.exe, for example
              C:\Programs\perl\bin\perl.exe --help=FAQ

    Performance Problems

        There are various reasons when the program responds slow, or seems to
        hang. Performance issues are most likely a target-side problem.  Most
        common reasons are (no specific order):

          a) DNS resolver problems
             Try with  --no-dns

          b) target does not accept connections for https
             Try with  --no-http

          c) target's certificate is not valid
             Try with  --no-cert

          d) target expects that the client provides a client certificate
             No option provided yet ...

          e) target does not handle Server Name Indication (SNI)
             Try with  --no-sni

          f) use of external "openssl(1)" executable
             Use  --no-openssl

          g) target does not respond at all and/or blocks
             Use  --ssl-error
             For a detailed description, please see Connection Problems.

        Other options which may help to get closer to the problem's cause:
        --trace-time,  --timeout=SEC,  --trace,  --trace-cmd

        Using  --trace-time   should show following times:
          * DNS:             1 -  10 sec
          * need_default:    <5 sec
          * need_cipher:     1 - 299 sec (+cipher with socket)
          * need_cipher:     1 -  20 sec (+cipherraw)
          * no SNI:          1 -  10 sec
          * connection test: 1 -   5 sec
          * prepare checks:  2 -  20 sec
          *   checkalpn.     1 -  15 sec
          *   checkprot.     1 -  15 sec
          * cipher:          <1 sec
          * info:            <1 sec
          * check:           <1 sec



        Some commands cannot be used together with others, for example:
        +cipher,  +ciphers,  +list,  +libversion,  +version,  +check,  +help,
        +protocols .

        +quick  should not be used together with other commands, it returns
        strange output then. It is the only command which allows  +cipher
        together with other commands.

        +protocols  requires "openssl(1)" with support for  '-nextprotoneg'
        option. Otherwise the value will be empty.


        The option  --port=PORT  must preceed  --host=HOST  for a target like
        HOST:PORT  .

        The characters  '+' and '='  cannot be used for  --separator=CHAR

        Following strings should not be used in any value for options:
          '+check', '+info', '+quick', '--header'
        as they my trigger the  --header   option unintentional.

        The used "timeout(1)" command cannot be defined with a full path like
       "openssl(1)" can with the  --openssl=path/to/openssl .

        --cfg-text=FILE  cannot be used to redefine the texts  'yes' and 'no'
        as used in the output for  +cipher  command.

    Checks (general)


          This check is only done for the certificate provided by the target.
          All other certificate in the chain are not checked.

          This is currently (2018) a limitation in

    Broken pipe

        This error message most likely means that the connection to specified
        target was not possible (firewall or whatever reason).

    Target Certificate Chain Verification

        The systems default capabilities i.e., openssl, are used to
        verify the target's certificate chain.  Unfortunately various systems
        have implemented different  approaches and rules how identify and how
        to report a successful verification.  As a consequence  this tool can
        only return the  same information about the chain verification as the
        used underlying tools.  If that information is trustworthy depends on
        how trustworthy the tools are.

        These limitations apply to following commands:
          * +verify
          * +selfsigned

        Following commands and options are useful to get more information:
          * +chain_verify,  +verify,  +error_verify,  +chain,  +s_client
          * --ca-file,  --ca-path,  --ca-depth

    User Provided Files

        Please note that there cannot be any guarantee that the code provided
        in the  DEBUG-FILE "" or  USER-FILE "" will
        work flawless. Obviously this is the user's responsibility.

    Problems and Errors

        Checking the target for supported ciphers may return that a cipher is
        not supported by the server  misleadingly.  Reason is most likely  an
        improper timeout for the connection. See  --timeout=SEC  option.

        If the specified targets accepts connections but does not speak  SSL,
        the connection will be closed after the system's TCP/IP-timeout. This
        script will hang (about 2-3 minutes).

        If reverse DNS lookup fails, an error message is returned as hostname,
        like:  '<<gethostbyaddr() failed>>'.
        Workaround to get rid of this message: use  --no-dns  option.

        All checks for EV are solely based on the information provided by the

        Some versions of openssl (< 1.x) may not support all required options
        which results in various error messages,  or  more worse,  may not be
        visibale at all. Available functionalitity of openssl will be checked
        for right at the beginning. Proper warnings and hints are printed.
        Following table shows the openssl option and how to disable it within
          * -nextprotoneg       --no-nextprotoneg
          * -reconnect          --no-reconnect
          * -tlsextdebug        --no-tlsextdebug
          * -alpn               --no-alpn

    Connection Problems

        Sometimes the connection cannot be established. This may have various
        reasons.  Unfortunaly this script seems to hang then.  In  particular
        when checking for ciphers with  +cipher  or  +cipherall  . The reason
        is most likely that the server does not respond to the TCP/IP request
        and hence the script closes the connection after the configured time-
        out (see  --timeout=SEC  option).

        Continous connection attempts  can be inhibited with the  --ssl-error
        option, which is set by default. Avoiding further connections results
        in a loss of information and consequentely, leads to wrong checks.

        It is a trade-off to wait for all information done accurately,  or to
        get the results quickly. The logic to stop connecting for --ssl-error
        can be controlled with following additional options:
          * --ssl-error-max=CNT     - max. continous errors
          * --ssl-error-timeout=SEC - treat a failure as error after timeout
          * --ssl-error-total=CNT   - max. amount of errors

        This means that no more connections are made when more than
          * --ssl-error-max errors occour sequentialy
          * --ssl-error-total errors occoured

          * --ssl-error-max=3
          * --ssl-error-timeout=6
          * --ssl-error-total=6

        no more connections are made if for example  any sequence of timeouts
              0 5 2 2                   - --ssl-error-max matches
              0 1 3 0 0 0 4 1 2 2 2     - --ssl-error-max matches
              0 5 0 2 0 2 2 0 2 0 2     - --ssl-error-total matches

        This allows to fine-tune the condition when to stop connecting to the
        target. For example, continous but not consecutive timeouts may indi-
        cate a bad or instable network connection, but not that the target to
        be connected blocks. In such a case sequence of timeouts like follows
        may be observed (assuming --ssl-error-max=3):
              0 5 1 2 2 2 4 2 3 2 3 3 3 2
              . . . ^                 ^____ stop for --ssl-error-timeout=3
              . . . |______________________ stop for --ssl-error-timeout=2

        On normal (even slow) network connections  dozens of  connections per
        second are usual, hence the timeout is always  0 or 1.  Based on that
        experience  --ssl-error  is enabled and set with defaults as follows:
          * --ssl-error-max=5
          * --ssl-error-timeout=1
          * --ssl-error-total=10

    Poor Systems

        Use of "openssl(1)" is disabled by default on  Windows due to various
        performance problems. It needs to be enabled with  --openssl  option.

        On Windows the usage of  "openssl s_client" needs to be enabled using
        --s_client  option.

        On Windows it's a pain to specify a correct path for  --openssl=TOOL
        option. Variants are:
          * --openssl=/path/to/openssl.exe
          * --openssl=X:/path/to/openssl.exe
          * --openssl=\path\to\openssl.exe
          * --openssl=X:\path\to\openssl.exe
          * --openssl=\\path\\to\\openssl.exe
          * --openssl=X:\\path\\to\\openssl.exe

        You have to fiddle around to find the proper one.

    Debug and Trace Output

        When both  --trace-key  and  --trace-cmd  options are used, output is
        mixed, obviously. Hint: output for --trace-cmd always contains "CMD".

        Any  --trace*  option implies  --trace-time .


        All perl modules and all  private moduels and files  will be searched
        for using paths  available in the  '@INC'  variable.  '@INC'  will be
        prepended by following paths:

          * .
          * ./lib
          * INSTALL_PATH
          * INSTALL_PATH/lib

        Where  'INSTALL_PATH'  is the path where the tool is installed.
        To see which files have been included use:
     +version --v --user

    Perl Modules

        * "IO::Socket::SSL(1)"
        * "IO::Socket::INET(1)"
        * "Net::SSLeay(1)"
        * "Net::SSLinfo"
        * "Net::SSLhello"

    Additional files used if requested

        * ""
        * ""
        * ""
        * "o-saft-README"
        * o-saft-docker


        The tool can be installed in any path. It just requres the modules as
        described in  DEPENDENCIES  above. However, it's recommended that the
        modules "Net::SSLhello" and "Net::SSLinfo" are found in the directory
        './Net/'  where  ''  is installed.

        For security reasons, most modern libraries  disabled or even removed
        insecure or "dirty" functionality.  As the purpose of this tool is to
        detect such insecure settings, functions, etc.,  it needs these dirty
        things enabled. It needs (incomplete list):

          * insecure protocols like SSLv2, SSLv3
          * more ciphers enabled, like NULL-MD5, AECDH-NULL-SHA, etc.
          * some SSL extensions and options

        Therefore we recommend to compile and install at least following:

          * OpenSSL  with SSLv2, SSLv3 and more ciphers enabled
          * Net::SSLeay  compiled with openssl version as described before.

        Please read the  SECURITY  section first before following the install
        instructions below.


        Currently (since 18.06.18) it is recommend to build openssl using

        Other possibilities are:
          * compiling openssl using following sources
            see  Example: Compile OpenSSL,
          * use any of the precomiled versions provided by
          * use Docker owasp/o-saft (which contains a special openssl)

        The sources are available at
        A precomiled static versions are available at
          * (see bin directory there)

        For all following installation examples we assume:
          * or openssl-1.0.2d.tar.gz
          * /usr/local as base installation directory
          * a bourne shell (sh) compatible shell

    Example: Precompiled OpenSSL

        Simply download the tarball or zip file for your platform, unpack it,
        and install (copy) the binaries into a directory of your choice.

    Example: Compile OpenSSL

        OpenSSL can be used from or, as recommended, from .

        Compiling and installing the later is as simple as:

              cd openssl-1.0.2-chacha
              ./config --shared -Wl,-rpath=/usr/local/lib
              make test
              make install

        which will install openssl,,  and some include
        files as well as the include files in  /usr/local/ .
        The shared version of the libraries are necessary for  Net::SSLeay.
        Building openssl from the offical  sources requires some
        patching before compiling and installing the libraries and binaries.

        Example with openssl-1.0.2d:

              echo == unpack tarball
              tar xf openssl-1.0.2d.tar.gz
              cd openssl-1.0.2d

              echo == backup files to be modified
              cp ssl/s2_lib.c{,.bak}
              cp ssl/s3_lib.c{,.bak}
              cp ssl/ssl3.h{,.bak}
              cp ssl/tls1.h{,.bak}

              echo == patch files
              vi ssl/tls1.h         +/TLS1_ALLOW_EXPERIMENTAL_CIPHERSUITES/
                  # define TLS1_ALLOW_EXPERIMENTAL_CIPHERSUITES  1
              vi ssl/ssl3.h ssl/s{2,3}_lib.c   +"/# *if 0/"
                  #==> remove all   # if 0  and corresponding  #endif
                  #    except if lines contain:
                  #        _FZA
                  #        /* Fortezza ciphersuite from SSL 3.0
                  #        /* Do not set the compare functions,
                  #        if (s->shutdown  SSL_SEND_SHUTDOWN)&

              echo == configure with static libraries
              echo omitt the zlib options if zlib-1g-dev is not installed
              echo omitt the krb5 options if no kerberos libraries available
              LDFLAGS="-rpath=$LD_RUN_PATH" & export LDFLAGS&
              ./config --prefix=/usr/local --openssldir=/usr/local/ssl \
                  enable-zlib zlib zlib-dynamic enable-ssl2 \
                  enable-krb5 --with-krb5-flavor=MIT \
                  enable-mdc2 enable-md2 enable-rc5  enable-rc2 \
                  enable-cms  enable-ec  enable-ec2m enable-ecdh enable-ecdsa \
                  enable-gost enable-seed enable-idea enable-camellia \
                  enable-rfc3779 enable-ec_nistp_64_gcc_128 \
                  experimental-jpake -fPIC \

              echo == make binaries and libraries
              make depend
              make test
              make install

              echo == if you want static binaries and libraries
              make clean
              echo same ./config as before but without shared option
              ./config --prefix=/usr/local --openssldir=/usr/local/ssl \
                  enable-zlib zlib zlib-dynamic enable-ssl2 \
                  enable-krb5 --with-krb5-flavor=MIT \
                  enable-mdc2 enable-md2 enable-rc5  enable-rc2 \
                  enable-cms  enable-ec  enable-ec2m enable-ecdh enable-ecdsa \
                  enable-gost enable-seed enable-idea enable-camellia \
                  enable-rfc3779 enable-ec_nistp_64_gcc_128 \
                  experimental-jpake -fPIC  -static \
              make depend
              make test
              echo next make will overwrite the previously installed dynamic
              echo shared openssl binary with the static openssl binary
              make install

    Example: Compile Net::SSLeay

        To enable support for ancient protocol versions,  Net::SSLeay must be
        compiled manually after patching 'SSLeay.xs' (see below).
        Reason is, that  Net::SSLeay  enables some functionality for  SSL/TLS
        according the identified openssl version. There is, currently (2015),
        no possibility to enable this functionality  by passing options on to
        the configuration script 'perl Makefile.PL'.

        Building our own library and module (with openssl from '/usr/local'):

              echo == unpack tarball
              tar xf Net-SSLeay-1.72.tar.gz
              cd Net-SSLeay-1.72

              echo == patch files
              echo "edit SSLeay.xs and change some #if as described below"
              LDFLAGS="-rpath=$LD_RUN_PATH" & export LDFLAGS&
              env OPENSSL_PREFIX=/usr/local perl Makefile.PL PREFIX=/usr/local \
                  INC=-I/usr/local/include  DEFINE=-DOPENSSL_BUILD_UNSAFE=1
              make install
              cd /tmp & +version&

        SSLeay.xs needs to be changed as follows:
          * search for
              #ifndef OPENSSL_NO_SSL2
              #if OPENSSL_VERSION_NUMBER < 0x10000000L

              const SSL_METHOD *


              #ifndef OPENSSL_NO_SSL3
              #if OPENSSL_VERSION_NUMBER < 0x10002000L

              const SSL_METHOD *


          * and replace by
              const SSL_METHOD *

              const SSL_METHOD *

        Note that  Net::SSLeay  will be installed in '/usr/local/' then. This
        can be adapted to your needs by passing another path to the  'PREFIX'
        and  'DESTDIR'  parameter.

        Following command can be used to check  which methods are avilable in
        Net::SSLeay, hence above patches can be verified:

              perl -MNet::SSLinfo -le 'print Net::SSLinfo::ssleay_test();'

    Testing OpenSSL

        After installation as descibed above finished, openssl may be tested:

              echo already installed openssl (found with PATH environment)
              openssl ciphers -v
              openssl ciphers -V -ssl2
              openssl ciphers -V -ssl3
              openssl ciphers -V ALL
              openssl ciphers -V ALL:COMPLEMENTOFALL
              openssl ciphers -V ALL:eNULL:EXP

              echo own compiled and installed openssl
              /usr/local/openssl ciphers -v
              /usr/local/openssl ciphers -V -ssl2
              /usr/local/openssl ciphers -V -ssl3
              /usr/local/openssl ciphers -V ALL
              /usr/local/openssl ciphers -V ALL:COMPLEMENTOFALL
              /usr/local/openssl ciphers -V ALL:eNULL:EXP

        The difference should be obvious.
        Note, the commands using  'ALL:COMPLEMENTOFALL'  and  'ALL:eNULL:EXP'
        should return the same result.

    Testing Net::SSLeay

        As we want to test the separately installed  Net::SSLeay,  it is best
        to do it with  itself:


        we should see a line similar to follwong at the end of the output:
              Net::SSLeay   1.72  /usr/local/lib/x86_64-linux-gnu/perl/5.20.2/Net/

        Now check for supported (known) ciphers:

     ciphers -V

        we should see lines similar to those of the last '/usr/local/openssl'
        call. However, it should contain more cipher lines.

    Stand-alone Executable

        Some people asked for a stand-alone executable (mainly for Windows).
        Even perl is a scripting language there are situations where a stand-
        alone executable would be nice, for example if the installed perl and
        its libraries are outdated, or if perl is missing at all.

        Currently (2016) there are following possibilities to generate such a
        stand-alone executable:

          * perl with PAR::Packer module
              pp -C -c
              pp -C -c -M Net::DNS -M Net::SSLeay -M IO::Socket \
                          -M Net::SSLinfo -M Net::SSLhello -M osaft
              pp -C -c
              pp -C -c -M Net::DNS

          * ActiveState perl with its perlapp
              perlapp --clean
              perlapp --clean -M Net::DNS -M Net::SSLeay -M IO::Socket \
                          -M Net::SSLinfo -M Net::SSLhello -M osaft
              perlapp --clean
              perlapp --clean -M Net::DNS -M osaft

          * perl2exe from IndigoSTar

        For details  on building the executable,  for example  how to include
        all required modules, please refer to the documentation of the tool.

        Note that  pre-build executables (build by perlapp, perl2exe)  cannot
        be provided due to licence problems.
        Also note that using  stand-alone executable have not been tested the
        same way as the  itself. Use them at your own risk.


        The tool can be used inside a Docker image. To start  inside
        the Docker image, use following:

              o-saft-docker +info some.tld
              docker run --rm -it owasp/o-saft +info some.tld

        For more details, please refer to:

              o-saft-docker usage
              o-saft-docker -help


        The Docker image can be installed as follows:

              docker pull owasp/o-saft

        The image can also easily be build from the Dockerfile (which is part
        of the distribution) as follows:

              o-saft-docker build

        To build the image from the Dockerfile with docker commands, see:

              o-saft-docker -n build

        For more details, please refer to:

              o-saft-docker -help


        * "openssl(1)", "Net::SSLeay(1)", "Net::SSLhello", "Net::SSLinfo", "timeout(1)"
        * "IO::Socket::SSL(1)", "IO::Socket::INET(1)"
        * o-saft, o-saft-docker, o-saft-docker-dev, Dockerfile, docker


    Note on SSL versions

        Automatically detecting the supported SSL versions of the underlaying
        system is a hard job and not always possible. Reasons could be:

        * used perl modules (Socket::SSL, Net::SSLeay) does not handle errors
          properly. Erros may be:
              invalid SSL_version specified at ... IO/Socket/
              Use of uninitialized value in subroutine entry at lib/IO/Socket/

          There're some workarounds implemented since version 15.11.15 .

        * the underlaying libssl does not support the version, which then may
          result in segmentation fault

        * the underlaying libssl is newer than the perl module and the module
          has not been reinstalled. This most often happens with  Net::SSLeay
          This can be detected with (see version numbers for Net::SSLeay):

        * perl (in particular a used module, see above)  may bail out  with a
          compile error, like
              Can't locate auto/Net/SSLeay/ in @INC ...

          There're some workarounds implemented since version 15.11.15 .

        We try to detect unsupported versions and disable them automatically,
        a warning like follwoing is shown then:
              **WARNING: SSL version 'SSLv2': not supported by openssl

        All such warnings look like:
              **WARNING: SSL version 'SSLv2': ...

        If problems occour with  SSL versions, following commands and options
        may help to get closer to the reason or can be used as workaround:
     +version --v
     +version | grep versions
     +version | grep 0x
     +protocols your.tld
     +protocols your.tld --no-rc

        Checking for SSL version is done at one place in the code, search for
              supported SSL versions

        However, there are some dirty hacks where  SSLv2 and SSLv3 is checked

    Using private and

        For all  cryptographic functionality  the libraries  installed on the
        system will be used. In particular perl's "Net::SSLeay(1)" module, the
        system's and  and the "openssl(1)" executable.

        It is possible to provide your own libraries, if the  perl module and
        the executable are  linked using  dynamic shared objects  (aka shared
        library, position independent code).
        The appropriate option is  --lib=PATH.

        On most systems these libraries are loaded at startup of the program.
        The runtime loader uses a preconfigured list of directories  where to
        find these libraries. Also most systems provide a special environment
        variable to specify  additional paths  to directories where to search
        for libraries, for example the  LD_LIBRARY_PATH environment variable.
        This is the default environment variable used herein.  If your system
        uses  another name it must be specified with the  --envlibvar=NAME
        option, where  NAME  is the name of the environment variable.

    Understanding  --exe=PATH, --lib=PATH, --openssl=TOOL

        If any of  --exe=PATH  or  --lib=PATH  is provided, the pragram calls
        ('exec') itself recursively with all given options, except the option
        itself. The environment variables  'LD_LIBRARY_PATH'  and 'PATH'  are
        set before executing as follows:
          * prepend  'PATH'  with all values given with  --exe=PATH
          * prepend  'LD_LIBRARY_PATH'  with all values given with --lib=PATH

        This is exactly, what Cumbersome Approach below describes. So these
        option simply provide a shortcut for that.

        Note that  --openssl=TOOL  is a full path to the  openssl  executable
        and will not be changed.  However, if it is a relative path, it might
        be searched for using the previously set  'PATH'  (see above).

        Note that  'LD_LIBRARY_PATH'  is the default.  It can be changed with
        the  --envlibvar=NAME  option.

        While  --exe  mainly impacts the "openssl(1)" executable,  --lib  also
        impacts itself, as it loads other shared libraries if found.

        Bear in mind that  all these options  can affect the behaviour of the
        openssl subsystem,  influencing both  which executable is called  and
        which shared libraries will be used.

        NOTE that no checks are done if the options are set proper. To verify
        the settings, following commands may be used:
 --lib=YOUR-PATH --exe=YOUR-EXE +version
 --lib=YOUR-PATH --exe=YOUR-EXE --v +version
 --lib=YOUR-PATH --exe=YOUR-EXE --v --v +version

        Why so many options?  Exactly as described above, these options allow
        the users to tune the behaviour of the tool to their needs.  A common
        use case is to enable the use of a separate openssl build independent
        of the openssl package used by the operating system.  This allows the
        user fine grained control over openssl's encryption suites  which are
        compiled/available, without affecting the core system.


        Depending on your system and the used modules and executables, it can
        be tricky to replace the configured shared libraries with own ones.
        Reasons are:
          a) the linked library name contains a version number,
          b) the linked library uses a fixed path,
          c) the linked library is searched at a predefined path,
          d) the executable checks the library version when loaded.

        Only the first one a) can be circumvented.  The last one d) can often
        be ignored as it only prints a warning or error message.

        To circumvent the "name with version number" problem try following:

        1) use "ldd(1)" (or a similar tool) to get the names used by openssl:

              ldd /usr/bin/openssl

        which returns something like:

     => /lib/ (0x00007f940cb6d000)
     => /lib/ (0x00007f940c7de000)
     => /lib/x86_64-linux-gnu/ (0x00007f940c5d9000)
     => /lib/x86_64-linux-gnu/ (0x00007f940c3c1000)
     => /lib/x86_64-linux-gnu/ (0x00007f940c02c000)
              /lib64/ (0x00007f940cdea000)

        Here only the first two libraries are important.  Both,
        and  need to be version "0.9.8" (in this example).

        2) create a directory for your libraries, i.e.:

              mkdir /tmp/dada

        3) place your libraries there, assuming they are:


        4) create symbolic links in that directory:

              ln -s
              ln -s

        5) test program with following option:

     +libversion --lib=/tmp/dada
     +list --v   --lib=/tmp/dada


     +libversion --lib=/tmp/dada -exe=/path/to-openssl
     +list --v   --lib=/tmp/dada -exe=/path/to-openssl

        6) start program with your options, i.e.:

     --lib=/tmp/dada +ciphers

        This works if "openssl(1)" uses the same shared libraries as
       "Net::SSLeay(1)",  which most likely is the case.

        It's tested with Unix/Linux only. It may work on other platforms also
        if they support such an environment variable and the installed
       "Net::SSLeay(1)" and "openssl(1)" are linked using dynamic shared

        Depending on  compile time settings  and/or  the location of the used
        tool or lib, a warning like following may occur:

              WARNING: can't open config file: /path/to/openssl/ssl/openssl.cnf

        This warning can be ignored, usually as  req  or  ca  sub commands of
        openssl is not used here.
        To fix the problem, either use  --openssl-cnf=FILE  option or set the
        the environment variable OPENSSL_CONF properly.

      Cumbersome Approach

        A more cumbersome approach to call  this program is to set  following
        environment variables in your shell:


      Windows Caveats

        I.g. the used libraries on Windows are libeay32.dll and ssleay32.dll.

        Windows also supports the LD_LIBRARY_PATH environment variable. If it
        does not work as expected with that variable, it might be possible to
        place the libs in the same directory as the  corresponding executable
        (which is found by the PATH environment variable).

    Using CGI mode

        This script can be used as  CGI application. Output is the same as in
        common CLI mode, using  'Content-Type:text/plain'.  Keep in mind that
        the used modules like "Net::SSLeay(1)" will write some debug messages
        on  STDERR instead  STDOUT.  Therefore multiple  --v  and/or  --trace
        options behave slightly different.

        No additional external files like  RC-FILE  or  DEBUG-FILE  are read
        in CGI mode; they are silently ignored.
        Some options are disabled in CGI mode  because they are dangerous  or
        don't make any sense.


          There are  no  input data validation checks implemented herein. All
          input data is url-decoded once and then used verbatim.
          More advanced checks must be done outside before calling this tool.

        It is not recommended to run this tool in CGI mode.
        You have been warned!

    Using user specified code

        There are some functions called within the program flow, which can be
        filled with any perl code.  Empty stubs of the functions are prepared
        in "".  See also  USER-FILE .


    Debugging, Tracing

        Following  options and commands  are useful for hunting problems with
        SSL connections and/or this tool. Note that some options can be given
        multiple times to increase amount of listed information. Also keep in
        mind that it's best to specify  --v  as very first argument.

        Note that the file "" is required,  if any  --trace*  or
        --v   option is used.


        * +dump
        * +libversion
        * +s_client
        * +todo
        * +version


        * --v
        * --v--
        * --trace
        * --trace-arg
        * --trace-cmd
        * --trace-key

        Empty or undefined strings are written as  '<<undefined>>'  in texts.
        Some parameters, in particular those of  HTTP responses,  are written
        as  '<<response>>'.  Long parameter lists are abbreviated with '...'.


        When using  --v  and/or  --trace  options,  additional output will be
        prefixed with a  '#'  (mainly as first, left-most character.
        Following formats are used:

             Additional text for verbosity (--v options).

           #[variable name][TAB]
             Internal variable name (--trace-key options).

             Trace information for --trace  options.

             Trace information from  NET::SSLinfo  for  --trace  options.
             These are data lines in the format:
              #{ variable name : value #}

             Note that 'value'  here can span multiple lines and ends with:

    Using outdated modules

        The tools was designed to work with old perl modules too.  When using
        old modules, a proper  '**WARNING:'  will be printed. These warinings
        cannot be switched of using  --no-warning  .
        The warning also informs about the missing functionality or check.

        I.g. it is best to install newer versions of the module if possible.
        A good practice to check if modules are available in a proper version
        is to call:

 +version --v --v

        Following example shows the result without warnings:

              === reading: ./ (RC-FILE done) ===
              === reading: Net/ (O-Saft module done) ===
              === reading: Net/ (O-Saft module done) ===
              === ./ 16.09.09 ===
                  ::OPENSSL_VERSION_NUMBER()       0x268443744
                  ::SSLeay()                       0x268443744
                  Net::SSLeay::SSLeay_version()    OpenSSL 1.0.2-chacha (1.0.2f-dev)
              = openssl =
                  version of external executable   OpenSSL 1.0.2-chacha (1.0.2f-dev)
                  external executable              /opt/openssl-chacha/bin/openssl
                  used environment variable (name) LD_LIBRARY_PATH
                  environment variable (content)   <<undef>>
                  path to shared libraries
                  full path to openssl.cnf file    <<undef>>
                  common openssl.cnf files         /usr/lib/ssl/openssl.cnf \
                  .                                /etc/ssl/openssl.cnf \
                  .                                /System//Library/OpenSSL/openssl.cnf \
                  .                                /usr/ssl/openssl.cnf
                  URL where to find CRL file       <<undef>>
                  directory with PEM files for CAs /opt/tools/openssl-chacha/ssl/certs
                  PEM format file with CAs         /etc/ssl/certs/ca-certificates.crt
                  common paths to PEM files for CAs /etc/ssl/certs /usr/lib/certs \
                  .                                 /System/Library/OpenSSL
                  common PEM filenames for CAs     ca-certificates.crt certificates.crt certs.pem
                  number of supported ciphers      177
                  openssl supported SSL versions   SSLv3 TLSv1 TLSv11 TLSv12
         known SSL versions     SSLv2 SSLv3 TLSv1 TLSv11 TLSv12 TLSv13 \
                  .                                DTLSv09 DTLSv1 DTLSv11 DTLSv12 DTLSv13
              = +cipherall =
                  default list of ciphers          0x03000000 .. 0x030000FF, 0x0300C000 .. 0x0300C0FF,
                  .                                0x0300CC00 .. 0x0300CCFF, 0x0300FE00 .. 0x0300FFFF,
              = Required (and used) Modules =
                  @INC                 ./ ./lib . /bin /usr/share/perl5 \
                  .                    /usr/lib/x86_64-linux-gnu/perl5/5.20 \
                  .                    /usr/lib/x86_64-linux-gnu/perl/5.20 \
                  .                    /usr/share/perl/5.20 /usr/local/lib/site_perl .
              =   module name            VERSION  found in
              =   ----------------------+--------+------------------------------------------
                  IO::Socket::INET       1.35     /usr/lib/x86_64-linux-gnu/perl/5.20/IO/Socket/
                  IO::Socket::SSL        2.002    /usr/share/perl5/IO/Socket/
                  Net::DNS               0.81     /usr/lib/x86_64-linux-gnu/perl5/5.20/Net/
                  Net::SSLeay            1.72     /usr/lib/x86_64-linux-gnu/perl5/5.20/Net/
                  Net::SSLinfo           16.06.01 Net/
                  Net::SSLhello          16.05.16 Net/
                  osaft                  16.05.10

        Following example shows the result with warnings (line nr. may vary):

              === reading: ./ (RC-FILE done) ===
              === reading: ./Net/ (O-Saft module done) ===
              **WARNING: ancient Net::SSLeay 1.35 < 1.49; cannot use ::initialize at /Net/ line 481.
              === reading: ./Net/ (O-Saft module done) ===
              **WARNING: ancient perl has no 'version' module; version checks may not be accurate; at line 1662.
              **WARNING: ancient Net::SSLeay 1.35 < 1.49 detected; at line 1687.
              **WARNING: ancient IO::Socket::SSL 1.22 < 1.37 detected; at line 1687.
              **WARNING: ancient version IO::Socket::SSL 1.22 < 1.90 does not support SNI or is known to be buggy; SNI disabled; at line 5905.
              !!Hint: --force-openssl can be used to disables this check
              **WARNING: ancient version Net::SSLeay 1.35 < 1.49  may throw warnings and/or results may be missing; at line 5934.
              **WARNING: SSL version 'TLSv11': not supported by Net::SSLeay; not checked
              **WARNING: SSL version 'TLSv12': not supported by Net::SSLeay; not checked
              **WARNING: SSL version 'TLSv13': not supported by Net::SSLeay; not checked
              === 16.09.09 ===
                  ::OPENSSL_VERSION_NUMBER()       0x9470143
              **WARNING: ancient version Net::SSLeay 1.35 < 1.49; cannot compare SSLeay with openssl version at line 4778.
                  ::SSLeay()                       0x1.35
              **WARNING: ancient version Net::SSLeay 1.35 < 1.49; detailed version not available at line 4806.
              = openssl =
                  version of external executable   OpenSSL 0.9.8y 5 Feb 2013
                  external executable              /usr/bin/openssl
                  used environment variable (name) LD_LIBRARY_PATH
                  environment variable (content)   <<undef>>
                  path to shared libraries
                  full path to openssl.cnf file    <<undef>>
                  common openssl.cnf files         /usr/lib/ssl/openssl.cnf \
                  .                                /etc/ssl/openssl.cnf \
                  .                                /System//Library/OpenSSL/openssl.cnf \
                  .                                /usr/ssl/openssl.cnf
                  URL where to find CRL file       <<undef>>
                  directory with PEM files for CAs /System/Library/OpenSSL/certs
                  PEM format file with CAs         <<undef>>
                  common paths to PEM files for CAs /etc/ssl/certs /usr/lib/certs /System/Library/OpenSSL
                  common PEM filenames for CAs     ca-certificates.crt certificates.crt certs.pem
                  number of supported ciphers      43
                  openssl supported SSL versions   SSLv2 SSLv3 TLSv1
         known SSL versions     SSLv2 SSLv3 TLSv1 TLSv11 TLSv12 TLSv13 \
                  .                                DTLSv09 DTLSv1 DTLSv11 DTLSv12 DTLSv13
              **WARNING: ancient version Net::SSLeay 1.35 < 1.49; cannot compare SSLeay with openssl version at line 4778.
              **WARNING: used openssl version '9470143' differs from compiled Net:SSLeay '1.35'; ignored
              = +cipherall =
                  default list of ciphers          0x03000000 .. 0x030000FF, 0x0300C000 .. 0x0300C0FF,
                  .                                0x0300CC00 .. 0x0300CCFF, 0x0300FE00 .. 0x0300FFFF,
              = Required (and used) Modules =
                  @INC                 ./ ./lib /bin /Library/Perl/Updates/5.10.0 \
                  .                    /System/Library/Perl/5.10.0/darwin-thread-multi-2level \
                  .                    /System/Library/Perl/5.10.0 \
                  .                    /Library/Perl/5.10.0/darwin-thread-multi-2level \
                  .                    /Library/Perl/5.10.0 \
                  .                    /Network/Library/Perl/5.10.0/darwin-thread-multi-2level \
                  .                    /Network/Library/Perl/5.10.0 \
                  .                    /Network/Library/Perl \
                  .                    /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level \
                  .                    /System/Library/Perl/Extras/5.10.0 .
              =   module name            VERSION  found in
              =   ----------------------+--------+------------------------------------------
                  IO::Socket::INET       1.31     /System/Library/Perl/5.10.0/darwin-thread-multi-2level/IO/Socket/
                  IO::Socket::SSL        1.22     /System/Library/Perl/Extras/5.10.0/IO/Socket/
                  Net::DNS               0.65     /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level/Net/
                  Net::SSLeay            1.35     /System/Library/Perl/Extras/5.10.0/darwin-thread-multi-2level/Net/
                  Net::SSLinfo           16.06.01 ./Net/
                  Net::SSLhello          16.05.16 ./Net/
                  osaft                  16.05.10 /

        Please keep in mind that the shown version numbers and the shown line
        numbers are examples and may differ on your system.

        When starting with outdated modules, more '**WARNING:' will
        be shown. The warnings depend on the installed version of the module.  is known to work with at least:
              IO::Socket::INET 1.31, IO::Socket::SSL 1.22, Net::DNS 0.65
              Net::SSLeay 1.30


        When talking about "testing the tool", functional tests are meant. So
        this section describes "developer" rather that "user" options.

        Testing the tool is a challenging task. Beside the oddities described
        elsewhere, for example  Name Rodeo,  there are a bunch of problems
        and errors which may occour during runtime.

        Following options and commands are available to improve testing. They
        mainly can simulate error conditions or stop execution properly (they
        are not intended for other use cases):


          Stop execution after processing all arguments and before precessing
          any target. The runtime configuration is complete at this point.


          Terminate tool at specified 'KEY'. For available 'KEY', please see:
              grep exit=


          With this option values in the internal  %cfg  hash can be set:

              $cfg{KEY} = VALUE
          Only (perl) scalars or arrays can be set. The type will be detected

          Example,  this option can be used to change the text used as prefix
          in each output line triggerd by the  --v  option:
     --cfg-init=prefix_verbose="#VERBOSE: "

          or the text used as prefix triggerd by the  --trace  option:
     --cfg-init=prefix_trace="#TRACE: "


        ( in all following examples is the name of the tool)


 +cipher some.tld
 +info   some.tld
 +check  some.tld
 +quick  some.tld
 +certificate  some.tld
 +fingerprint  some.tld 444
 +after +dates some.tld
 +version --v
 +list    --v

    Some specials

        * Get an idea how messages look like
 +check --cipher=RC4 some.tld

        * Check for Server Name Indication (SNI) usage only
 +sni some.tld

        * Check for SNI and print certificate's subject and altname
 +sni +cn +altname some.tld

        * Check for all SNI, certificate's subject and altname issues
 +sni_check some.tld

        * Only print supported ciphers
 +cipher --enabled some.tld

        * Only print unsupported ciphers
 +cipher --disabled some.tld

        * Test for a specific ciphers
 +cipher --cipher=ADH-AES256-SHA some.tld

        * Test all ciphers, even if not supported by local SSL implementation
 +cipherraw some.tld
 +cipherall some.tld
 +cipherall some.tld --range=full
 example.tld --range=full --v

        * Show supported (enabled) ciphers with their DH parameters:
 +cipher-dh some.tld

        * Test using a private, and openssl
 +cipher --lib=/foo/bar-1.42 --exe=/foo/bar-1.42/apps some.tld

        * Test using a private openssl
 +cipher --openssl=/foo/bar-1.42/openssl some.tld

        * Test using a private openssl also for testing supported ciphers
 +cipher --openssl=/foo/bar-1.42/openssl --force-openssl some.tld

        * Use your private texts in output
 +check some.tld --cfg-text=desc="my special description"

        * Use your private texts from RC-FILE
 --help=cfg-text >>
            edit as needed:
 +check some.tld

        * Use your private hint texts in output
 +check some.tld --cfg-hint=renegotiation="my special hint text"

        * Get the certificate's Common Name for a bunch of servers:
 +cn example.tld some.tld other.tld
 +cn example.tld some.tld other.tld --showhost --no-header

        * Generate simple parsable output
 --legacy=quick --no-header +info  some.tld
 --legacy=quick --no-header +check some.tld
 --legacy=quick --no-header --trace-key +info  some.tld
 --legacy=quick --no-header --trace-key +check some.tld

        * Generate simple parsable output for multiple hosts
 --legacy=quick --no-header --trace-key --showhost +check some.tld other.tld

        * Just for curiosity
 some.tld +fingerprint --format=raw
 some.tld +certificate --format=raw | openssl x509 -noout -fingerprint

    Specials for hunting problems with connections etc.

        * Do not read RC-FILE
 +info some.tld --no-rc

        * Show command line argument processing
 +info some.tld --trace-arg

        * Simple tracing
 +cn   some.tld --trace
 +info some.tld --trace

        * A bit more tracing
 +cn   some.tld --trace --trace

        * Show internal variable names in output
 +info some.tld --trace-key

        * Show internal argument processeing
 +info --trace-arg some.tld

        * Show internal control flow
 +info some.tld --trace-cmd

        * Show internal timing
 +info some.tld --trace-time

        * Show checking ciphers
 +cipher some.tld --v --v

        * Show values retrieved from target certificate directly
 +info some.tld --no-cert --no-cert --no-cert-text=Value-from-Certificate

        * Show certificate CA verifications
 some.tld +chain_verify +verify +error_verify +chain

        * Avoid most performance and timeout problems (don't use  --v)
 +info some.tld --no-dns --no-sni --ignore-no-conn
 +info some.tld --no-dns --no-sni --no-cert --no-http --no-openssl

        * Identify timeout problems
 +info some.tld --trace-cmd

          this will show lines containing:
          #O-Saft  CMD: test ...


        Based on ideas (in alphabetical order) of:

        *, sslscan,,,

        * O-Saft - OWASP SSL advanced forensic tool
            Thanks to Gregor Kuznik for this title.

        * +cipherraw and some proxy functionality implemented by Torsten Gigler.

        * For re-writing some docs in proper English, thanks to Robb Watson.

        * Code to check heartbleed vulnerability adapted from
            Steffen Ullrich (08. April 2014):

        * Colouration inspired by .


        @(#) 19.01.19


        31. July 2012 Achim Hoffmann (at) sicsec de

        Project Home:

Updated on: 2021-Nov-26