Mercurial > dropbear

comparison libtomcrypt/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c @ 302:973fccb59ea4 ucc-axis-hack

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propagate from branch 'au.asn.ucc.matt.dropbear' (head 11034278bd1917bebcbdc69cf53b1891ce9db121) to branch 'au.asn.ucc.matt.dropbear.ucc-axis-hack' (head 10a1f614fec73d0820c3f61160d9db409b9beb46)
author Matt Johnston <matt@ucc.asn.au>
date Sat, 25 Mar 2006 12:59:58 +0000
parents 1b9e69c058d2
children 0cbe8f6dbf9e
comparison
equal deleted inserted replaced
299:740e782679be 302:973fccb59ea4
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_decode_object_identifier.c
15 ASN.1 DER, Decode Object Identifier, Tom St Denis
16 */
17
18 #ifdef LTC_DER
19 /**
20 Decode OID data and store the array of integers in words
21 @param in The OID DER encoded data
22 @param inlen The length of the OID data
23 @param words [out] The destination of the OID words
24 @param outlen [in/out] The number of OID words
25 @return CRYPT_OK if successful
26 */
27 int der_decode_object_identifier(const unsigned char *in, unsigned long inlen,
28 unsigned long *words, unsigned long *outlen)
29 {
30 unsigned long x, y, t, len;
31
32 LTC_ARGCHK(in != NULL);
33 LTC_ARGCHK(words != NULL);
34 LTC_ARGCHK(outlen != NULL);
35
36 /* header is at least 3 bytes */
37 if (inlen < 3) {
38 return CRYPT_INVALID_PACKET;
39 }
40
41 /* must be room for at least two words */
42 if (*outlen < 2) {
43 return CRYPT_BUFFER_OVERFLOW;
44 }
45
46 /* decode the packet header */
47 x = 0;
48 if ((in[x++] & 0x1F) != 0x06) {
49 return CRYPT_INVALID_PACKET;
50 }
51
52 /* get the length */
53 if (in[x] < 128) {
54 len = in[x++];
55 } else {
56 if (in[x] < 0x81 || in[x] > 0x82) {
57 return CRYPT_INVALID_PACKET;
58 }
59 y = in[x++] & 0x7F;
60 len = 0;
61 while (y--) {
62 len = (len << 8) | (unsigned long)in[x++];
63 }
64 }
65
66 if (len < 1 || (len + x) > inlen) {
67 return CRYPT_INVALID_PACKET;
68 }
69
70 /* decode word1 and word2 */
71 --len;
72 t = in[x++];
73 words[0] = t/40;
74 words[1] = t%40;
75
76 /* decode rest */
77 y = 2;
78 t = 0;
79 while (len--) {
80 t = (t << 7) | (in[x] & 0x7F);
81 if (!(in[x++] & 0x80)) {
82 /* store t */
83 if (y >= *outlen) {
84 return CRYPT_BUFFER_OVERFLOW;
85 }
86 words[y++] = t;
87 t = 0;
88 }
89 }
90
91 *outlen = y;
92 return CRYPT_OK;
93 }
94
95 #endif
96
97 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/object_identifier/der_decode_object_identifier.c,v $ */
98 /* $Revision: 1.1 $ */
99 /* $Date: 2005/05/16 15:08:11 $ */