--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/pk/asn1/der/generalizedtime/der_length_generalizedtime.c	Fri Feb 09 21:44:05 2018 +0800
@@ -0,0 +1,58 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_length_utctime.c
+  ASN.1 DER, get length of GeneralizedTime, Steffen Jaeckel
+  Based on der_length_utctime.c
+*/
+
+#ifdef LTC_DER
+
+/**
+  Gets length of DER encoding of GeneralizedTime
+  @param gtime        The GeneralizedTime structure to get the size of
+  @param outlen [out] The length of the DER encoding
+  @return CRYPT_OK if successful
+*/
+int der_length_generalizedtime(ltc_generalizedtime *gtime, unsigned long *outlen)
+{
+   LTC_ARGCHK(outlen  != NULL);
+   LTC_ARGCHK(gtime != NULL);
+
+   if (gtime->fs == 0) {
+      /* we encode as YYYYMMDDhhmmssZ */
+      *outlen = 2 + 14 + 1;
+   } else {
+      unsigned long len = 2 + 14 + 1;
+      unsigned fs = gtime->fs;
+      do {
+         fs /= 10;
+         len++;
+      } while(fs != 0);
+      if (gtime->off_hh == 0 && gtime->off_mm == 0) {
+         /* we encode as YYYYMMDDhhmmss.fsZ */
+         len += 1;
+      }
+      else {
+         /* we encode as YYYYMMDDhhmmss.fs{+|-}hh'mm' */
+         len += 5;
+      }
+      *outlen = len;
+   }
+
+   return CRYPT_OK;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */