comparison 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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191:1c15b283127b 209:39d5d58461d6
1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
2 *
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
5 *
6 * The library is free for all purposes without any express
7 * guarantee it works.
8 *
9 * Tom St Denis, [email protected], http://libtomcrypt.org
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file der_length_octet_string.c
15 ASN.1 DER, get length of OCTET STRING, Tom St Denis
16 */
17
18 #ifdef LTC_DER
19 /**
20 Gets length of DER encoding of OCTET STRING
21 @param noctets The number of octets in the string to encode
22 @param outlen [out] The length of the DER encoding for the given string
23 @return CRYPT_OK if successful
24 */
25 int der_length_octet_string(unsigned long noctets, unsigned long *outlen)
26 {
27 LTC_ARGCHK(outlen != NULL);
28
29 if (noctets < 128) {
30 /* 04 LL DD DD DD ... */
31 *outlen = 2 + noctets;
32 } else if (noctets < 256) {
33 /* 04 81 LL DD DD DD ... */
34 *outlen = 3 + noctets;
35 } else if (noctets < 65536UL) {
36 /* 04 82 LL LL DD DD DD ... */
37 *outlen = 4 + noctets;
38 } else if (noctets < 16777216UL) {
39 /* 04 83 LL LL LL DD DD DD ... */
40 *outlen = 5 + noctets;
41 } else {
42 return CRYPT_INVALID_ARG;
43 }
44
45 return CRYPT_OK;
46 }
47
48 #endif
49
50
51 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/octet/der_length_octet_string.c,v $ */
52 /* $Revision: 1.1 $ */
53 /* $Date: 2005/05/16 15:08:11 $ */