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comparison libtomcrypt/src/pk/asn1/der/utf8/der_decode_utf8_string.c @ 478:d4f32c3443ac dbclient-netcat-alike

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propagate from branch 'au.asn.ucc.matt.dropbear' (head f21045c791002d81fc6b8dde6537ea481e513eb2) to branch 'au.asn.ucc.matt.dropbear.dbclient-netcat-alike' (head d1f69334581dc4c35f9ca16aa5355074c9dd315d)
author Matt Johnston <matt@ucc.asn.au>
date Sun, 14 Sep 2008 06:47:51 +0000
parents 0cbe8f6dbf9e
children f849a5ca2efc
comparison
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296:6b41e2cbf071 478:d4f32c3443ac
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.com
10 */
11 #include "tomcrypt.h"
12
13 /**
14 @file der_decode_utf8_string.c
15 ASN.1 DER, encode a UTF8 STRING, Tom St Denis
16 */
17
18
19 #ifdef LTC_DER
20
21 /**
22 Store a UTF8 STRING
23 @param in The DER encoded UTF8 STRING
24 @param inlen The size of the DER UTF8 STRING
25 @param out [out] The array of utf8s stored (one per char)
26 @param outlen [in/out] The number of utf8s stored
27 @return CRYPT_OK if successful
28 */
29 int der_decode_utf8_string(const unsigned char *in, unsigned long inlen,
30 wchar_t *out, unsigned long *outlen)
31 {
32 wchar_t tmp;
33 unsigned long x, y, z, len;
34
35 LTC_ARGCHK(in != NULL);
36 LTC_ARGCHK(out != NULL);
37 LTC_ARGCHK(outlen != NULL);
38
39 /* must have header at least */
40 if (inlen < 2) {
41 return CRYPT_INVALID_PACKET;
42 }
43
44 /* check for 0x0C */
45 if ((in[0] & 0x1F) != 0x0C) {
46 return CRYPT_INVALID_PACKET;
47 }
48 x = 1;
49
50 /* decode the length */
51 if (in[x] & 0x80) {
52 /* valid # of bytes in length are 1,2,3 */
53 y = in[x] & 0x7F;
54 if ((y == 0) || (y > 3) || ((x + y) > inlen)) {
55 return CRYPT_INVALID_PACKET;
56 }
57
58 /* read the length in */
59 len = 0;
60 ++x;
61 while (y--) {
62 len = (len << 8) | in[x++];
63 }
64 } else {
65 len = in[x++] & 0x7F;
66 }
67
68 if (len + x > inlen) {
69 return CRYPT_INVALID_PACKET;
70 }
71
72 /* proceed to decode */
73 for (y = 0; x < inlen; ) {
74 /* get first byte */
75 tmp = in[x++];
76
77 /* count number of bytes */
78 for (z = 0; (tmp & 0x80) && (z <= 4); z++, tmp = (tmp << 1) & 0xFF);
79
80 if (z > 4 || (x + (z - 1) > inlen)) {
81 return CRYPT_INVALID_PACKET;
82 }
83
84 /* decode, grab upper bits */
85 tmp >>= z;
86
87 /* grab remaining bytes */
88 if (z > 1) { --z; }
89 while (z-- != 0) {
90 if ((in[x] & 0xC0) != 0x80) {
91 return CRYPT_INVALID_PACKET;
92 }
93 tmp = (tmp << 6) | ((wchar_t)in[x++] & 0x3F);
94 }
95
96 if (y > *outlen) {
97 *outlen = y;
98 return CRYPT_BUFFER_OVERFLOW;
99 }
100 out[y++] = tmp;
101 }
102 *outlen = y;
103
104 return CRYPT_OK;
105 }
106
107 #endif
108
109 /* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utf8/der_decode_utf8_string.c,v $ */
110 /* $Revision: 1.7 $ */
111 /* $Date: 2006/11/26 02:27:37 $ */