Allow callers to force ASN.1 date encoding as GENERALIZEDTIME.

src/libstrongswan/asn1/asn1.c

@@ -426,9 +426,8 @@ time_t asn1_to_time(const chunk_t *utctime, asn1_t type)
 /**
  *  Convert a date into ASN.1 UTCTIME or GENERALIZEDTIME format
  */
-chunk_t asn1_from_time(const time_t *time)
+chunk_t asn1_from_time(const time_t *time, asn1_t type)
 {
-	asn1_t type;
 	int offset;
 	const char *format;
 	char buf[BUF_LEN];
@@ -437,8 +436,10 @@ chunk_t asn1_from_time(const time_t *time)
 
 	gmtime_r(time, &t);
 	/* RFC 5280 says that dates through the year 2049 MUST be encoded as UTCTIME
-	 * and dates in 2050 or later MUST be encoded as GENERALIZEDTIME */
-	type = (t.tm_year < 150) ? ASN1_UTCTIME : ASN1_GENERALIZEDTIME;
+	 * and dates in 2050 or later MUST be encoded as GENERALIZEDTIME. We only
+	 * enforce the latter to avoid overflows but allow callers to force the
+	 * encoding to GENERALIZEDTIME */
+	type = (t.tm_year >= 150) ? ASN1_GENERALIZEDTIME : type;
 	if (type == ASN1_GENERALIZEDTIME)
 	{
 		format = "%04d%02d%02d%02d%02d%02dZ";

src/libstrongswan/asn1/asn1.h

@@ -191,12 +191,13 @@ time_t asn1_to_time(const chunk_t *utctime, asn1_t type);
 /**
  * Converts time_t to an ASN.1 UTCTIME or GENERALIZEDTIME string
  *
- * The type is automatically chosen based on the encoded year.
+ * @note The type is automatically changed to GENERALIZEDTIME if needed
  *
  * @param time		time_t in UTC
+ * @param type		ASN1_UTCTIME or ASN1_GENERALIZEDTIME
  * @return			body of an ASN.1 code time object
  */
-chunk_t asn1_from_time(const time_t *time);
+chunk_t asn1_from_time(const time_t *time, asn1_t type);
 
 /**
  * Parse an ASN.1 UTCTIME or GENERALIZEDTIME object