Provide method for returning certificate expiration time stamp.
We convert ASN1 time via std::tm to int64_t representing milliseconds-since-epoch. We do not use time_t since that cannot store milliseconds, and expires for 32-bit platforms in 2038 also for seconds.
Conversion via std::tm might might seem silly, but actually doesn't add any complexity.
One would expect tm -> seconds-since-epoch to already exist on the standard library. There is mktime, but it uses localtime (and sets an environment variable, and has the 2038 problem).
The ASN1 TIME parsing is limited to what is required by RFC 5280.
BUG=webrtc:5150
R=hbos@webrtc.org, nisse@webrtc.org, tommi@webrtc.org
Review URL: https://codereview.webrtc.org/1468273004 .
Cr-Commit-Position: refs/heads/master@{#10854}
diff --git a/webrtc/base/timeutils.cc b/webrtc/base/timeutils.cc
index fac5b66..05e9ad8 100644
--- a/webrtc/base/timeutils.cc
+++ b/webrtc/base/timeutils.cc
@@ -204,4 +204,48 @@
return unwrapped_ts;
}
+int64_t TmToSeconds(const std::tm& tm) {
+ static short int mdays[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+ static short int cumul_mdays[12] = {0, 31, 59, 90, 120, 151,
+ 181, 212, 243, 273, 304, 334};
+ int year = tm.tm_year + 1900;
+ int month = tm.tm_mon;
+ int day = tm.tm_mday - 1; // Make 0-based like the rest.
+ int hour = tm.tm_hour;
+ int min = tm.tm_min;
+ int sec = tm.tm_sec;
+
+ bool expiry_in_leap_year = (year % 4 == 0 &&
+ (year % 100 != 0 || year % 400 == 0));
+
+ if (year < 1970)
+ return -1;
+ if (month < 0 || month > 11)
+ return -1;
+ if (day < 0 || day >= mdays[month] + (expiry_in_leap_year && month == 2 - 1))
+ return -1;
+ if (hour < 0 || hour > 23)
+ return -1;
+ if (min < 0 || min > 59)
+ return -1;
+ if (sec < 0 || sec > 59)
+ return -1;
+
+ day += cumul_mdays[month];
+
+ // Add number of leap days between 1970 and the expiration year, inclusive.
+ day += ((year / 4 - 1970 / 4) - (year / 100 - 1970 / 100) +
+ (year / 400 - 1970 / 400));
+
+ // We will have added one day too much above if expiration is during a leap
+ // year, and expiration is in January or February.
+ if (expiry_in_leap_year && month <= 2 - 1) // |month| is zero based.
+ day -= 1;
+
+ // Combine all variables into seconds from 1970-01-01 00:00 (except |month|
+ // which was accumulated into |day| above).
+ return (((static_cast<int64_t>
+ (year - 1970) * 365 + day) * 24 + hour) * 60 + min) * 60 + sec;
+}
+
} // namespace rtc