A small perl script that checks a target server whether it is prone to BEAST vulnerability via target preferred cipher. It assumes no workaround (i.e. EMPTY FRAGMENT) applied in target server. Some sources said this workaround was disabled by default for compatibility reasons. This may be the reason why RC4 ciphersuite was widely chosen as highest preferred ciphersuite for the primary workaround.

$ ./beast.pl

===============================================

SSL/TLS BEAST Vulnerability Check
 by YGN Ethical Hacker Group, http://yehg.net/

===============================================

Usage: beast.pl host [port]

port = 443 by default {optional}

$ ./beast.pl www.hotmail.com

===============================================

SSL/TLS BEAST Vulnerability Check
 by YGN Ethical Hacker Group, http://yehg.net/

===============================================

Target: www.hotmail.com:443

## The target is PRONE to BEAST attack. ##

Protocol: TLS v1
Server Preferred Cipher: AES128-SHA
Vulnerable: YES

$ ./beast.pl www.google.com

===============================================

SSL/TLS BEAST Vulnerability Check
 by YGN Ethical Hacker Group, http://yehg.net/

===============================================

Target: www.google.com:443

## The target is NOT vulnerable to BEAST attack. ##

Protocol: TLS v1
Server Preferred Cipher: ECDHE-RSA-RC4-SHA
Vulnerable: NO

SSLsplit is a tool for man-in-the-middle attacks against SSL/TLS encrypted network connections.  Connections are transparently intercepted through a network address translation engine and redirected to SSLsplit.  SSLsplit terminates SSL/TLS and initiates a new SSL/TLS connection to the original destination address, while logging all data transmitted.  SSLsplit is intended to be useful for network forensics and penetration testing.

SSLsplit supports plain TCP, plain SSL, HTTP and HTTPS connections over both IPv4 and IPv6.  For SSL and HTTPS connections, SSLsplit generates and signs forged X509v3 certificates on-the-fly, based on the original server certificate subject DN and subjectAltName extension.  SSLsplit fully supports Server Name Indication (SNI) and is able to work with RSA, DSA and ECDSA keys and DHE and ECDHE cipher suites.  SSLsplit can also use existing certificates of which the private key is available, instead of generating forged ones.  SSLsplit supports NULL-prefix CN certificates and can deny OCSP requests in a generic way.

Requirements

SSLsplit depends on the OpenSSL and libevent 2.x libraries. The build depends on GNU make and a POSIX.2 environment in `PATH`. The (optional) unit tests depend on check.

SSLsplit currently supports the following operating systems and NAT engines:

Installation

    make
    make test       # optional unit tests
    make install    # optional install

Dependencies are autoconfigured using pkg-config.  If dependencies are not
picked up and fixing `PKG_CONFIG_PATH` does not help, you can specify their
respective locations manually by setting `OPENSSL_BASE`, `LIBEVENT_BASE` and/or
`CHECK_BASE` to the respective prefixes.

You can override the default install prefix (`/usr/local`) by setting `PREFIX`.
 

Development

SSLsplit is being developed on Github.  For bug reports, please use the Github
issue tracker.  For patch submissions, please send me pull requests.

Download SSLsplit 0.4.5