Description:
------------
In asn1_time_to_time_t [ext/openssl/openssl.c], the Y2K bug makes a cameo 
appearance:
[...]
*thestr = '\0';
thestr -= 2;
thetime.tm_year = atoi(thestr);

if (thetime.tm_year < 68) {
  thetime.tm_year += 100;
}

This piece of code is the part of a backwards UTCTime parser. It moves 2 
positions to the left, and converts those two characters to an int.

However, certs with a validity past 2050 contain GeneralizedTime formatted 
timestamps allowing 4 characters in the year field instead of the UTCTime this 
function parses (badly). [rfc5280, 4.1.2.5]

Test script:
---------------
An example script that demonstrates the problem with a cert expiring 2101:
http://pastebin.com/Yij0q1qn

Expected result:
----------------
Actual time string of validity:  21010828070405Z
parsed with strtotime:           4154655845 [2101-08-28]
parsed with asn1_time_to_time_t: 4154655845  [2101-08-28]

Actual result:
--------------
Actual time string of validity:  21010828070405Z
parsed with strtotime:           4154655845 [2101-08-28]
parsed with asn1_time_to_time_t: 998982245  [2001-08-28]