1 /* LibTomCrypt, modular cryptographic library -- Tom St Denis */
2 /* SPDX-License-Identifier: Unlicense */
3 #include "tomcrypt_private.h"
4
5 /**
6 @file der_encode_utf8_string.c
7 ASN.1 DER, encode a UTF8 STRING, Tom St Denis
8 */
9
10
11 #ifdef LTC_DER
12
13 /**
14 Store an UTF8 STRING
15 @param in The array of UTF8 to store (one per wchar_t)
16 @param inlen The number of UTF8 to store
17 @param out [out] The destination for the DER encoded UTF8 STRING
18 @param outlen [in/out] The max size and resulting size of the DER UTF8 STRING
19 @return CRYPT_OK if successful
20 */
der_encode_utf8_string(const wchar_t * in,unsigned long inlen,unsigned char * out,unsigned long * outlen)21 int der_encode_utf8_string(const wchar_t *in, unsigned long inlen,
22 unsigned char *out, unsigned long *outlen)
23 {
24 unsigned long x, y, len;
25 int err;
26
27 LTC_ARGCHK(in != NULL);
28 LTC_ARGCHK(out != NULL);
29 LTC_ARGCHK(outlen != NULL);
30
31 /* get the size */
32 for (x = len = 0; x < inlen; x++) {
33 if (!der_utf8_valid_char(in[x])) return CRYPT_INVALID_ARG;
34 len += der_utf8_charsize(in[x]);
35 }
36 if ((err = der_length_asn1_length(len, &x)) != CRYPT_OK) {
37 return err;
38 }
39 x += len + 1;
40
41 /* too big? */
42 if (x > *outlen) {
43 *outlen = x;
44 return CRYPT_BUFFER_OVERFLOW;
45 }
46
47 /* encode the header+len */
48 x = 0;
49 out[x++] = 0x0C;
50
51 y = *outlen - x;
52 if ((err = der_encode_asn1_length(len, out + x, &y)) != CRYPT_OK) {
53 return err;
54 }
55 x += y;
56
57 /* store UTF8 */
58 for (y = 0; y < inlen; y++) {
59 switch (der_utf8_charsize(in[y])) {
60 case 1: out[x++] = (unsigned char)in[y]; break;
61 case 2: out[x++] = 0xC0 | ((in[y] >> 6) & 0x1F); out[x++] = 0x80 | (in[y] & 0x3F); break;
62 case 3: out[x++] = 0xE0 | ((in[y] >> 12) & 0x0F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break;
63 #if !defined(LTC_WCHAR_MAX) || LTC_WCHAR_MAX > 0xFFFF
64 case 4: out[x++] = 0xF0 | ((in[y] >> 18) & 0x07); out[x++] = 0x80 | ((in[y] >> 12) & 0x3F); out[x++] = 0x80 | ((in[y] >> 6) & 0x3F); out[x++] = 0x80 | (in[y] & 0x3F); break;
65 #endif
66 default: break;
67 }
68 }
69
70 /* return length */
71 *outlen = x;
72
73 return CRYPT_OK;
74 }
75
76 #endif
77