version 0.3.33

[fms.git] / libs / libtomcrypt / pk / asn1 / der / octet / der_length_octet_string.c

diff --git a/libs/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c b/libs/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c
new file mode 100644 (file)
index 0000000..3caf352
--- /dev/null
+++ b/libs/libtomcrypt/pk/asn1/der/octet/der_length_octet_string.c
@@ -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, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+#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: 1.2 $ */
+/* $Date: 2006/03/31 14:15:35 $ */