1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
3 * LibTomCrypt is a library that provides various cryptographic
4 * algorithms in a highly modular and flexible manner.
6 * The library is free for all purposes without any express
9 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.com
14 @file der_decode_utf8_string.c
15 ASN.1 DER, encode a UTF8 STRING, Tom St Denis
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
29 int der_decode_utf8_string(const unsigned char *in, unsigned long inlen,
30 wchar_t *out, unsigned long *outlen)
33 unsigned long x, y, z, len;
35 LTC_ARGCHK(in != NULL);
36 LTC_ARGCHK(out != NULL);
37 LTC_ARGCHK(outlen != NULL);
39 /* must have header at least */
41 return CRYPT_INVALID_PACKET;
45 if ((in[0] & 0x1F) != 0x0C) {
46 return CRYPT_INVALID_PACKET;
50 /* decode the length */
52 /* valid # of bytes in length are 1,2,3 */
54 if ((y == 0) || (y > 3) || ((x + y) > inlen)) {
55 return CRYPT_INVALID_PACKET;
58 /* read the length in */
62 len = (len << 8) | in[x++];
68 if (len + x > inlen) {
69 return CRYPT_INVALID_PACKET;
72 /* proceed to decode */
73 for (y = 0; x < inlen; ) {
77 /* count number of bytes */
78 for (z = 0; (tmp & 0x80) && (z <= 4); z++, tmp = (tmp << 1) & 0xFF);
80 if (z > 4 || (x + (z - 1) > inlen)) {
81 return CRYPT_INVALID_PACKET;
84 /* decode, grab upper bits */
87 /* grab remaining bytes */
90 if ((in[x] & 0xC0) != 0x80) {
91 return CRYPT_INVALID_PACKET;
93 tmp = (tmp << 6) | ((wchar_t)in[x++] & 0x3F);
98 return CRYPT_BUFFER_OVERFLOW;
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 $ */