1# Debugging SSL on Linux
2
3To help anyone looking at the SSL code, here are a few tips I've found handy.
4
5[TOC]
6
7## Logging
8
9There are several flavors of logging you can turn on.
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11*   `SSLClientSocketImpl` can log its state transitions and function calls
12     using `base/logging.cc`.  To enable this, edit
13     `net/socket/ssl_client_socket_impl.cc` and change `#if 1` to `#if 0`. See
14     `base/logging.cc` for where the output goes (on Linux, usually stderr).
15
16*   `HttpNetworkTransaction` and friends can log its state transitions using
17    `base/trace_event.cc`. To enable this, arrange for your app to call
18    `base::TraceLog::StartTracing()`. The output goes to a file named
19    `trace...pid.log` in the same directory as the executable (e.g.
20    `Hammer/trace_15323.log`).
21
22## Network Traces
23
24http://wiki.wireshark.org/SSL describes how to decode SSL traffic. Chromium SSL
25unit tests that use `net/base/ssl_test_util.cc` to set up their servers always
26use port 9443 with `net/data/ssl/certificates/ok_cert.pem`, and port 9666 with
27`net/data/ssl/certificates/expired_cert.pem` This makes it easy to configure
28Wireshark to decode the traffic: do
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30Edit / Preferences / Protocols / SSL, and in the "RSA Keys List" box, enter
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32    127.0.0.1,9443,http,<path to ok_cert.pem>;127.0.0.1,9666,http,<path to expired_cert.pem>
33
34e.g.
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36    127.0.0.1,9443,http,/home/dank/chromium/src/net/data/ssl/certificates/ok_cert.pem;127.0.0.1,9666,http,/home/dank/chromium/src/net/data/ssl/certificates/expired_cert.pem
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38Then capture all tcp traffic on interface lo, and run your test.
39