Provided by: openvpn-blacklist_0.3_all
openvpn-vulnkey - check blacklist of compromised keys
openvpn-vulnkey [-q] file ...
openvpn-vulnkey checks a key against a blacklist of compromised keys.
A substantial number of keys are known to have been generated using a
broken version of OpenSSL distributed by Debian which failed to seed its
random number generator correctly. Keys generated using these OpenSSL
versions should be assumed to be compromised. This tool may be useful in
checking for such OpenVPN shared static keys. See openssl-vulnkey(1) for
details on checking SSL/TLS certificates.
Keys that are compromised cannot be repaired; replacements must be
generated using openvpn(8). Shared keys can be regenerated with:
$ openvpn --genkey --secret file
Quiet mode. openvpn-vulnkey(1). Normally, openvpn-vulnkey outputs the
fingerprint of each key scanned, with a description of its status. This
option suppresses that output.
BLACKLIST MD5SUM FORMAT
The blacklist file may start with comments, on lines starting with “#”.
After these initial comments, it must follow a strict format:
· Each line must consist of the lower-case hexadecimal MD5 key
fingerprint, and with the first 12 characters removed (that is,
the least significant 80 bits of the fingerprint).
The key fingerprint may be generated using
$ cat file.pem | sed ’/^[^0-9a-f]/d’ | md5sum | cut -d ’ ’ -f 1
This strict format is necessary to allow the blacklist file to be checked
Jamie Strandboge 〈email@example.com〉
Much of this manpage is based on Colin Watson’s ssh-vulnkey(1)