testssl.sh: Testing TLS/SSL encryption
testssl.sh is a free command line tool which checks a server's service
on any port for the support of TLS/SSL ciphers, protocols as well as some flaws.
It's designed to provide a clear output for a "is this good or bad" decision. It works for Linux and BSD out of the box –
no gems, CPAN, pip or the like.
As for security reasons some distributors
outphase the buggy stuff – and this is exactly you want to check for – it's recommended to compile OpenSSL by
yourself or check out the OpenSSL binaries below (Linux) – they come with a whopping 191 ciphers, ~80 more than on an average Linux distro. In any case: Except the ciphers, you will get a warning if your OpenSSL client
cannot perform a specific check, see below.
testssl.sh is pretty much portable. It is working on every recent Linux and BSD distribution.
It is supposed also to work on any other unixoid systems —
MacOSX and MSYS2. A newer OpenSSL version (1.0) is needed though.
Suggested is to have GNU tools installed (specifically /bin/bash and
New features (for development version 2.3dev see github (branch master):
- 2.2: Features (Dec 2014)
- works fully under BSD (openssl >=1.0)
- cipher check (-x) with pattern of hexcode/cipher
- check for POODLE SSL
- HPKP check
- OCSP stapling
- GOST and CHACHA20 POLY1305 cipher support
- service detection (HTTP, IMAP, POP, SMTP)
- runs now with all colors, b/w screen, no escape codes at all
- protocol check better
- job control removes stalling
- RFC <---> OpenSSL name space mapping of ciphers everywhere
- 2.0: Features (June 2014)
- server preferences for protocols and ciphers
- checks for: RC4, PFS, SPDY
- web and app server banner, HSTS
- server key size
- TLS session tickets
- TLS server extensions
- heartbleed check from bash-heartbleed.sh with shell only SSL handshake!
- CCS check from ccs-injection.sh with shell only SSL handshake!
- somewhat smart check for BREACH vulnerability
- check for CRIME
- prelease of cipher suites name space mapping OpenSSL <--> RFC
- aaand: neat output
- 1.40: cleanups, path of URL supplied on the command line (is ignored for now)
- 1.30: can test now for cipher suites / protocols only, tests for tls v1.1/v1.2 , -a/--all renamed
- 1.21: CRIME support, see http://threatpost.com/en_us/blogs/new-attack-uses-ssltls-information-leak-hijack-https-sessions-090512.
- 1.18: Rearragement of arguments: URI comes now always last. NOPARANOID flag tells whether medium grade ciphers are ok.
- 1.17: tests now for renegotiation vulnerabity, see (CVE-2009-3555)
- 1.16: Invoking options changed with this release. Port and hostname / URL will be accepted only as one argument. major code cleanups. Also
checks now whether SSL is listening on the server side at all. -a/--all tests cipher by cipher now.
- More see CHANGELOG.
The normal use case is probably just testssl.sh <hostname> , see first picture above.
The second picture with the
dark background shows a run from a FreeBSD 10 machine against a completey broken and not patched Ubuntu 12.04 machine. The features
not available locally on FreeBSD are in magenta, the dangerous ciphers, protocols and vulnerabilities
are in red.
Starting testssl.sh with no params will give you a general idea how to use it:
userid@somehost:~ % testssl.sh
where <options> is one of
<-h|--help> what you're looking at
<-b|--banner> displays banner + version
<-v|--version> same as above
<-V|--local> pretty print all local ciphers
<-V|--local> <hexcode> what cipher is <pattern hexcode>?
testssl.sh <options> URI
<-e|--each-cipher> check each local ciphers remotely
<-E|-ee|--cipher-per-proto> check those per protocol
<-f|--ciphers> check cipher suites
<-p|--protocols> check TLS/SSL protocols only
<-P|--preference> displays the servers picks: protocol+cipher
<-y|--spdy> checks for SPDY/NPN
<-x|--single-ciphers-test> <pattern> tests matched <pattern> of cipher
<-B|--heartbleed> tests only for heartbleed vulnerability
<-I|--ccs|--ccs_injection> tests only for CCS injection vulnerability
<-R|--renegotiation> tests only for renegotiation vulnerability
<-C|--compression|--crime> tests only for CRIME vulnerability
<-T|--breach> tests only for BREACH vulnerability
<-0|--poodleh> tests only for POODLE vulnerability
<-s|--pfs|--fs|--nsa> checks (perfect) forward secrecy settings
<-4|--rc4|--appelbaum> which RC4 ciphers are being offered?
<-H|--header|--headers> check for HSTS and server banner string
<t|--starttls> protocol does a default run against a STARTTLS enabled service
partly mandatory parameters:
URI host|host:port|URL|URL:port (port 443 is assumed unless otherwise specified)
pattern an ignore case word pattern of cipher hexcode or any other string in the name, kx or bits
protocol is one of ftp,smtp,pop3,imap,xmpp,telnet (for the latter you need e.g. the supplied openssl)
A STARTTLS check (see third picture on the lower left hand side, invoked with
testssl.sh -t pop3 pop.o2online.de:110) would be achieved with e.g.
testssl.sh --starttls smtp <smtphostname>.<tld>:587
testssl.sh -t xmpp <jabberhostname>.<tld>:5222
testssl.sh --starttls pop3 <pophostname>.<tld>:110
As the help says: Currently only one option at a time works. Note that the calling order has changed in 2.2. The second argument now is the protocol!
A neat feature: If you want to find out what local ciphers you have and
print them pretty, use testssl.sh -V. Ever wondered what hexcode a cipher is?
testssl.sh -V 9f lets you search for the hexcode 9f. You can also supply an ignore case
pattern in the output of a single cipher line, e.g. testssl.sh -V CBC puts out
every locally available cipher having the Cipher Block Chaining mode in its name.
If you have the file mapping-rfc.txt in the same directory testssl.sh -V displays the matching RFC style cipher
suite name. Also during every cipher suite test the corresponding RFC style name is
displayed. It's a broad output. If you don't want this, you need to move mapping-rfc.txt
A similar test can be performed with testssl.sh -x <pattern> URL .
Example: testssl.sh -x ECDH google.com checks google.com
for ECDH ciphers (and lists also not available ones at the target),
testssl.sh -x DHE smtp.posteo.de:465 does
a similar thing for the TLS enabled SMTP service – see picture on the lower right hand side.
Got it so far? Good.
Hint regarding OpenSSL binary
As mentioned above, a prerequisite for thoroughly checking SSL/TLS enabled servers is: all you want to check for has to be
available on your client. Transport encryption is not only depending on the server but also on your crypto provider on the client side –
especially if you want to use it for testing.
So there are drawbacks out of the Linux distributions boxes -- so to speak:
The worst test scenario is using libressl -- as it has lots of stuff disabled.A
- one cannot check 56 Bit ciphers as they are disabled during compile time.
- some ciphers are disabled for security reasons,
- support maybe not included (to disable CRIME)
- SSLv2 is often disabled
- and last but not least: SSLv3 seems to be outphased too
The signed tarball provides
specially compiled statically linked (except glibc and the loader)
OpenSSL binaries as a courtesy.
The newer version version also has ChaCha+Poly
ciphers on board. There are also Kerberos binaries included -- the latter ones require a bunch of
libraries (no static binaries). In the end those binaries will give you 191 ciphers as opposed to ~110 from standard Linux
You'll need to unpack my binaries, dump those you need either in
the same location as testssl.sh , named just openssl
or openssl.`uname -m` . You can also tell testssl.sh
via environment variable where your openssl binary is:
OPENSSL=<path_to_myopenssl> before you use testssl. Or issue
OPENSSL=<path_to_myopenssl> testssl.sh <hostname>
Don't try outdated OpenSSL versions before 1.0! Those versions are deprecated, you likely will not get very far.
testssl.sh is not locking those out but things might not work as expected. Support will be retired soon.
If you insist on using crippled binaries, you'll get a warning in magenta, see picture on the right hand side.
Feedback, bugs and contributions are welcome!
Currently there are two git repos @ github and @ nginx goodies on bitbucket (thx Markus setting the latter up). Here @ https://testssl.sh you will always find the stable version. At the github repo is the latest-greatest devel version.
Mailing list, bug tracker etc. will come soon.
me via github or send me an e-mail to dirk aet testssl dot sh.
I post all significant updates on Twitter (@drwetter).