diff src/pk/asn1/der/octet/der_length_octet_string.c @ 209:39d5d58461d6 libtomcrypt-orig LTC_1.05

Import of libtomcrypt 1.05
author Matt Johnston <matt@ucc.asn.au>
date Wed, 06 Jul 2005 03:53:40 +0000
parents
children d5faf4814ddb
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pk/asn1/der/octet/der_length_octet_string.c	Wed Jul 06 03:53:40 2005 +0000
@@ -0,0 +1,53 @@
+/* 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.
+ *
+ * Tom St Denis, [email protected], http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file der_length_octet_string.c
+  ASN.1 DER, get length of OCTET STRING, Tom St Denis
+*/
+
+#ifdef LTC_DER
+/**
+  Gets length of DER encoding of OCTET STRING 
+  @param noctets  The number of octets in the string to encode
+  @param outlen   [out] The length of the DER encoding for the given string
+  @return CRYPT_OK if successful
+*/
+int der_length_octet_string(unsigned long noctets, unsigned long *outlen)
+{
+   LTC_ARGCHK(outlen != NULL);
+
+   if (noctets < 128) {
+      /* 04 LL DD DD DD ... */
+      *outlen = 2 + noctets;
+   } else if (noctets < 256) {
+      /* 04 81 LL DD DD DD ... */
+      *outlen = 3 + noctets;
+   } else if (noctets < 65536UL) {
+      /* 04 82 LL LL DD DD DD ... */
+      *outlen = 4 + noctets;
+   } else if (noctets < 16777216UL) {
+      /* 04 83 LL LL LL DD DD DD ... */
+      *outlen = 5 + noctets;
+   } else {
+      return CRYPT_INVALID_ARG;
+   }
+
+   return CRYPT_OK;
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c,v $ */
+/* $Revision: 1.1 $ */
+/* $Date: 2005/05/16 15:08:11 $ */