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This is O-Saft's documentation as you get with: --help

On Windows following must be used --help --v

NAME - 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): example.tld --range=full example.tld 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 --help=examples
  • List all available commands: --help=commands
  • Get table of contents for complete help --help=toc
  • Show just one section, for example SECURITY, from help --help=SECURITY
  • 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 COMMANDS and OPTIONS
sections below. For more examples please refer to EXAMPLES section.
For more details, please see 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 a 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 not portable to other platforms.
In contrast to (all?) most other tools, including openssl, 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 recommend
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.


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 how and 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:
  • 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
  • LD_LIBRARY_PATH - used and extended with definitions from options
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 required:
  • 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 make 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's
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 below.
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 *RC4* ciphers
    • all *EXPORT* ciphers
    • all *anon* (aka ADH aka DHA) ciphers
    • all *CBC* and *CBC3* (aka 3DES) 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" and report the reason why it is considered
insecure otherwise. 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 --OPT 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 --help=cmd
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:
   $0 --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 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 known by this tool. This includes cryptogrphic
details of the cipher and some internal details about the rating.
In contrast to +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 +cipher 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, internal) commands are simply a shortcut for
a list of other commands. For details of the list use: --help=intern
Check the SSL connection for security issues. Implies +cipher .
+host +target
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. This is a shortcut
for all commands listed below but not including +cipher.
This command is intended for debugging as it prints some details
from the used Net::SSLinfo module.
Quick overview of checks. Implies --enabled and --short.
Check if servers offers ciphers with prefect forward secrecy (PFS)
Check for protocols supported by target.
Check for various vulnerabilities.
+sts +hsts
Various checks according STS HTTP header.
This option implies --http, means that --no-http is ignored.
Check for Server Name Indication (SNI) usage.
+sni_check +check_sni
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. 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=* option.
Note that ciphers not supported by the local SSL implementation
are not checked by default, use +cipherall or +cipherraw command for that.
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 details.

Same as +cipherraw but ouput format similat 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).
+cipher-null +null
Check if target accepts NULL ciphers.
+cipher-adh +adh
Check if target accepts ciphers with anonymous key exchange.
+cipher-exp +export
Check if target accepts EXPORT ciphers.
+cipher-cbc +cbc
Check if target accepts CBC ciphers.
+cipher-des +des
Check if target accepts DES ciphers.
Check if target accepts RC4 ciphers.
+cipher-edh +edh
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).
Commands to test SSL connection to target
Please see: --help=commands
Commands to show certificate details of the target
Please see: --help=commands
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-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 selected cipher by the server for each
+cipher-selected vs. +cipher-default
+cipher-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 selected cipher by the server for each
+cipher-strong vs. +cipher-default
+cipher-strong 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 options to show descriptions (this Options section).
Show available commands.
Show available commands with short description.
Show available options; short form.
Show available options with their description.
Show available checks.
--help=check-cfg --help=cfg-check
Show texts used as labels in output for checks (see +check) ready
for use in RC-FILE or as option.
Show available informations.
--help=data-cfg --help=cfg-data --help=cfg-info
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.
--help=hint-cfg --help=cfg-hint
Show texts used in hint messages ready for use in RC-FILE or as
Show texts used in various messages.
--help=text-cfg --help=cfg-text
Show texts used in various messages ready for use in RC-FILE or
as option.
Show possible legacy formats (used as value in --legacy=KEY).
Show available compliance checks.
Show internal commands.
Show list of cipherranges (see --cipherrange=RANG).
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.
--help=toc --help=content
Show headlines from help textsUseful to get an overview.
Show SECTION from documentation, see --help=toc for a list.
Example: --help=EXAMPLES
Show regular expressions used internally.
Show help text in HTML format.
Show help text in POD format.
Show help text in mediawiki format.
Generate HTML page with o-saft.cgi as form action..
--help=error --help=warning --help=problem
Show KNOWN PROBLEMS section with description of known error and
warning messages.
Show common abbreviation used in the world of security.
Show known problems and bugs.
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 target's PORT to be used. Legacy option.
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.
Example: +cmd host-1 --port 23 host-2 host-3:42 host-4
will connect to:
Make all connection to target using PROXYHOST.
Also possible is: --proxy=PROXYUSER:[email protected]:PROXYPORT
Make all connection to target using PROXYHOST:PROXYPORT.
Specify username for proxy authentication.
Specify password for proxy authentication.
--proxy=PROXYUSER:[email protected]:PROXYPORT is also possible.
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.
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.
--cgi, --cgi-exec
Internal use for CGI mode only.
Options for SSL tool
Do not read RC-FILE .
Read RC-FILE if exists, from directory where program was found.
Read RC-FILE path/to/FILE if exists.
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
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 informations 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 informations. 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
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).
--exe-path=PATH --exe=PATH
PATH is a full path where to find openssl.
--lib-path=PATH --lib=PATH
PATH is a full path where to find and
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 if the total
amount of errors increases --ssl-error-total=CNT.
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 ...
Timeout in seconds when connecting to the target (default: 2).
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 reuqested 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 like:
        Use of uninitialized value in subroutine entry at lib/IO/Socket/ line 430.
which occours with some versions of IO::Socket::SSL 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).
--sni-toggle --toggle-sni
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 in 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 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.
Do not use -nextprotoneg option for openssl.
Do not use -reconnect option for openssl.
Do not use -tlsextdebug option for openssl.
Argument or option passed to openssl s_client command.
Options for +cipher command
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.
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-lpn=, sets empty list.
  • --cipher-lpn=,, 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 (see also --cipherrange=RANGE):
  • rfc all ciphers defined in various RFCs
  • shifted rfc, shifted by 64 bytes to the right
  • long like rfc but more lazy list of
  • huge all constants 0x03000000 .. 0x0300FFFF
  • safe all constants 0x03000000 .. 0x032FFFFF
  • full all constants 0x03000000 .. 0x0300FFFF
  • SSLv2 all ciphers according RFC for SSLv2
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)
Do not abort testing for next cipher when the target responds with
"NoData" times out. Useful for TLS intolerant servers.
By default testing for ciphers is aborted when the target responds
with "noData message.
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.
--dns-mx, --mx
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
Use short less descriptive text labels for +check and +info
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).
Internal format: use tab as separator; ciphers are printed with bit
length (implies --tab).
Internal default format.
Internal format: print name of key instead of text as label. Key is
that of the internal data structure(s). For ciphers and protocols,
the corresponding hex value is used as key. Note that these values
are unique.
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 +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.
  • crnl 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.
Currently (Jan. 2018), these options must be used before any --help
Obsolete, please use --std-format=crnl .
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: --help=alias
Following list contains only those options not shown with: --help=alias
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
 --protocol SSL      (ssldiagnos)    same as --SSL
 --UDP               (ssldiagnos)    same as --udp
 --insecure          (      ignored
 --nopct --nocolor   (ssldiagnos)    ignored
 --timeout, --grep   (    ignored
 -r,  -s,  -t,  -x   (    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
To get a list of commands and their settings, use: --help=intern
Main purpose is to reduce list of commands or to print them sorted.
An example +preload can be found in .
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: --help=score
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.
--cfg_checks=KEY=TEXT --cfg_data=KEY=TEXT
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: --help=cfg_checks --help=cfg_data
Redefine the security value (i.e. HIGH) in the cipher description.
Example: --cfg-cipher=NULL-MD5=no-security-at-all ...
Redefine general texts used in output. Sets  %text{KEY} to TEXT.
To get a list of preconfigured texts, use: --help=cfg_text
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: --help=cfg-hint
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 +*).
[email protected]
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
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
Prints timestamp in trace output. More timestamps are printed if
used together with --trace-cmd.
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 istself.
--trace-sub +traceSUB
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
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:
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 "heartbead" 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 offeres 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.
Connection is vulnerable if target supports SSLv2 (with at least one cipher).
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.
Not implemented.
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.
Lucky 13
Check if CBC ciphers are offered.
NOTE the recommendation to be safe againts Lucky 13 was to use RC4
ciphers. But they are also subjetc 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
+rc4_cipher simply reports if RC4 ciphers are offered. However the
the check, and hence the result, is the same.
Check if DHE ciphers are used. Also check if the TLS session ticket
is random or not used at all.
Currently (2018) only a simple check is used: only DHE ciphers used.
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.
Target (server) Configuration and Support
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.
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
the key exceeds 16384 or 32768 bits. The check is against 16384 bits.
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= Cn 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
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
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 compliances,
and it is also difficult to check all these conditions. That's why some
of the compliances checks are not completely implemented, for details
please see blow.
Note that output of results of some checks is disabled in the RC-FILE
by default. A "**Hint:" message will be printed, if any of these checks
are used.
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
  • 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 RFC5280).
  • 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 Lucky 13-Angriff
  • 3.4.5 Die "Encrypt-thn-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 > 2000 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.
  • 4.1 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 +bsi-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 wildcards
  • 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 its 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 :character.
  • 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 (be 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
  • 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
Informations 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.
the keys in output).
Resource files are searched for and used automatically.
For details see RC-FILE below.
Debug files are searched for and used automatically.
For details see DEBUG-FILE below.
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 will be 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: ciphers
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--cfg_data=FILE only values for %data
will be set, and so on. KEY is not used when KEY=TEXT is an existing
filename. Though, it's 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
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 perl's @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 perl's @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 to get an idea about the mapping.
Use --help=regex to see which regex are used to handle all these
variants herein.
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 when 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.


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 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.
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 options like: --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: +version --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 +help --help
does not print anything.
Workaround: use --v option. +help --v
or +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: --help=FAQ
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: --help 
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
  • no SNI: 1 - 10 sec
  • connection test: 1 - 5 sec
  • need_default: <5 sec
  • need_cipher: 1 - 60 sec (+cipher with socket)
  • need_cipher: 1 - 20 sec (+cipherraw)
  • prepare checks: 2 - 20 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.
+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
The characters + and = cannot be used for --separator==CHAR option.
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
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 disbale 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 leading 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 - timeout when to treat a failure as error
  • --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 the path for --openssl=.. 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".


All perl modules and all private moduels and files will be searched
for using paths available in perl's @INC variable. @INC will
be prepended by following paths:
  • .
  • ./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(1)
  • Net::SSLhello(1)
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 this tool's purpose is to find
such insecure settings, functions, etc., it needs these dirty things
enabled. What we need is (incomplete list):
  • insecure protocols like SSLv2, SSLv3
  • more 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 it is recommend to use either the openssl version from which requires compilation,
see Example: Compile OpenSSL, or use any of the precomiled versions
which are available for several platforms at .
The sources are available at
The precomiled static versions are available at
For all following installation examples we assume:
  • or openssl-1.0.2d.tar.gz
  • /usr/local as bae 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/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
  ./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 \
  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.
   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"
   env OPENSSL_PREFIX=/usr/local perl Makefile.PL PREFIX=/usr/local \
         INC=/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 -MLNet::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: +version
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. With o-saft-docker and a
Dockerfile (both are part of the distribution), a proper Docker image
will be build easily. o-saft-docker can also be used to run commands
with inside the Docker image, example:
  o-saft-docker +info some.tld
For more details, please refer to:
  o-saft-docker -help
  o-saft-docker usage



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/
  • 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): +version
  • perl (in particular a used module, see above) may bail out with a
compile error, like
   Can't locate auto/Net/SSLeay/ in @INC ...
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
If problems occour with SSL versions, following commands and options
may help to to get closer to the reason or can be used as workaround: +version +version | grep versions +version | grep 0x +protocols your.tld +protocols your.tld --no-rc
If problems occour with SSL versions, following commands and options
Checking for SSL version is done at one place in the code, search for
    supported SSL versions
Using private and
For all cryptographic functionality the libraries installed on the
system will be used. This is in particular perl's Net:SSLeay module,
the system's and and the openssl 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_ 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=FILE
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=FILE 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 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=YOU-PATH --exe=YOUE-EXE +version --lib=YOU-PATH --exe=YOUE-EXE --v +version --lib=YOU-PATH --exe=YOUE-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 (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
or: +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 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's 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:
  • #<space>
Addition text for verbosity (--v options).
  • #[variable name]<TAB>
Internal variable name (--trace-key options).
  • #Net::SSLinfo::
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 +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 \
         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 \
         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:
     === 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 \
         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 0.66, Net::SSLeay 1.30


When talking about "testing the tool", functionl 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 error 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 at specified KEY. For available KEY please see: --help=exit
   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


($0 in all following examples is the name of the tool)
General +cipher some.tld +info   some.tld +check  some.tld +quick  some.tld +help=commands +list +list --v +certificate  some.tld +fingerprint  some.tld 444 +after +dates some.tld
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
  • Show current score settings --help=score
  • Change a single score setting --cfg_score=http_https=42   +check some.tld 
  • Use your private score settings from a file --help=score > magic.score
# edit as needed: magic.score --cfg_score    magic.score  +check 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.
  • 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 most 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 .


Achim Hoffmann


@(#) 16.09.16

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