allow 32-bit platforms to encode certs with dates > unix epoch (#4727)
Previously we used unix timestamps, but now we are switching to using
ASN1_TIME_set_string and automatically formatting the string based on
the year. The rule is as follows:
Per RFC 5280 (section 4.1.2.5.), the valid input time
strings should be encoded with the following rules:
1. UTC: YYMMDDHHMMSSZ, if YY < 50 (20YY) --> UTC: YYMMDDHHMMSSZ
2. UTC: YYMMDDHHMMSSZ, if YY >= 50 (19YY) --> UTC: YYMMDDHHMMSSZ
3. G'd: YYYYMMDDHHMMSSZ, if YYYY >= 2050 --> G'd: YYYYMMDDHHMMSSZ
4. G'd: YYYYMMDDHHMMSSZ, if YYYY < 2050 --> UTC: YYMMDDHHMMSSZ
Notably, Dates < 1950 are not valid UTCTime. At the moment we still
reject dates < Jan 1, 1970 in all cases but a followup PR can fix
that.
2 files changed
