1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
/* 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_decode_utf8_string.c
ASN.1 DER, encode a UTF8 STRING, Tom St Denis
*/
#ifdef LTC_DER
/**
Store a UTF8 STRING
@param in The DER encoded UTF8 STRING
@param inlen The size of the DER UTF8 STRING
@param out [out] The array of utf8s stored (one per char)
@param outlen [in/out] The number of utf8s stored
@return CRYPT_OK if successful
*/
int der_decode_utf8_string(const unsigned char *in, unsigned long inlen,
wchar_t *out, unsigned long *outlen)
{
wchar_t tmp;
unsigned long x, y, z, len;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(out != NULL);
LTC_ARGCHK(outlen != NULL);
/* must have header at least */
if (inlen < 2) {
return CRYPT_INVALID_PACKET;
}
/* check for 0x0C */
if ((in[0] & 0x1F) != 0x0C) {
return CRYPT_INVALID_PACKET;
}
x = 1;
/* decode the length */
if (in[x] & 0x80) {
/* valid # of bytes in length are 1,2,3 */
y = in[x] & 0x7F;
if ((y == 0) || (y > 3) || ((x + y) > inlen)) {
return CRYPT_INVALID_PACKET;
}
/* read the length in */
len = 0;
++x;
while (y--) {
len = (len << 8) | in[x++];
}
} else {
len = in[x++] & 0x7F;
}
if (len + x > inlen) {
return CRYPT_INVALID_PACKET;
}
/* proceed to decode */
for (y = 0; x < inlen; ) {
/* get first byte */
tmp = in[x++];
/* count number of bytes */
for (z = 0; (tmp & 0x80) && (z <= 4); z++, tmp = (tmp << 1) & 0xFF);
if (z > 4 || (x + (z - 1) > inlen)) {
return CRYPT_INVALID_PACKET;
}
/* decode, grab upper bits */
tmp >>= z;
/* grab remaining bytes */
if (z > 1) { --z; }
while (z-- != 0) {
if ((in[x] & 0xC0) != 0x80) {
return CRYPT_INVALID_PACKET;
}
tmp = (tmp << 6) | ((wchar_t)in[x++] & 0x3F);
}
if (y > *outlen) {
*outlen = y;
return CRYPT_BUFFER_OVERFLOW;
}
out[y++] = tmp;
}
*outlen = y;
return CRYPT_OK;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/utf8/der_decode_utf8_string.c,v $ */
/* $Revision: 1.7 $ */
/* $Date: 2006/11/26 02:27:37 $ */
|