NAME¶

sslsnoop.bt - Show SSL/TLS handshake events. Uses bpftrace/eBPF.

SYNOPSIS¶

sslsnoop.bt

DESCRIPTION¶

sslsnoop traces OpenSSL handshake functions, and shows latency and return value. This can be used to analyze SSL/TLS performance.

This tool works by dynamic tracing the uprobes in OpenSSL and related crypto libs, and may need updating to match future changes to these functions.

Since this uses BPF, only the root user can use this tool.

REQUIREMENTS¶

CONFIG_BPF and bpftrace.

EXAMPLES¶

Trace SSL/TLS handshake events, printing per-line summaries:

# sslsnoop.bt

FIELDS¶

TIME(us)

Time of the call completion, in microseconds since program start.

TID

Thread ID.

COMM

Process name.

LAT(us)

Latency of the call, in microseconds.

RET

Return value of the call.

FUNC

Function name.

OVERHEAD¶

SSL/TLS handshake usually contains network latency and the traced crypto functions are CPU intensive tasks, so call frequency should be low and the overhead of this tool is expected to be negligible.

SOURCE¶

This is from bpftrace.

https://github.com/bpftrace/bpftrace

Also look in the bpftrace distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

There is a bcc tool sslsniff that can show SSL/TLS handshake event latency before sniffing the plaintext in SSL_read/write. This tool provides more detailed crypto latency distribution during the handshake event.

https://github.com/iovisor/bcc

OS¶

Linux

STABILITY¶

Unstable - in development.

AUTHOR¶

Tao Xu

SEE ALSO¶

biosnoop.bt(8)