Provided by: openvpn-blacklist_0.3_all bug


     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.


     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


     openvpn(8) openssl-vulnkey(1)


     Jamie Strandboge 〈〉

     Much of this manpage is based on Colin Watson’s ssh-vulnkey(1)