This Go software takes a pcap network capture as input, analyzes it and outputs some numbers about TLS version and used ciphers, e.g.:
145876 packets analyzed. Here are the results:
=== TLS versions supported by clients ===
TLS 1.2 1846
TLS 1.0 24
=== TLS versions chosen by server ===
TLS 1.2 1936
=== Ciphers supported by clients: ===
TLS_RSA_WITH_AES_128_CBC_SHA 1866
TLS_RSA_WITH_AES_256_CBC_SHA 1866
TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA 1865
TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA 1865
TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA 1865
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA 1865
TLS_RSA_WITH_3DES_EDE_CBC_SHA 1748
[...]
=== Ciphers chosen by server ===
TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 1285
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 418
TLS_DHE_RSA_WITH_AES_256_CBC_SHA 202
TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 26
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 3
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 1
TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 1
=== TLS alerts ===
BAD_RECORD_MAC 46
PROTOCOL_VERSION 25
[UNKNOWN ALERT 0x000A] 4
INTERNAL_ERROR 2
Usage
Download or compile Tool. Downloads for Linux x86_64 available here
Record a network dump using tcpdump
E.g. for information on XMPP client connections (port 5222): tcpdump port 5222 -i eth0 -w tcpdump.pcap
Feed the network dump into the analyzer: ./tlsstats -d tcpdump.pcap
Development
This is not considered a very stable, rock solid tool. If you'd like to improve the code and make it more reliable / robust, go ahead and submit a pull request! :-)