5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 2002 - 2006 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; version 2 of the License.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
22 #include "silcstrutil.h"
24 static unsigned char pem_enc[64] =
25 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
27 /* Encodes data into PEM encoding. Returns NULL terminated PEM encoded
30 char *silc_pem_encode(unsigned char *data, SilcUInt32 len)
33 SilcUInt32 bits, c, char_count;
40 pem = silc_calloc(((len * 8 + 5) / 6) + 5, sizeof(*pem));
42 for (i = 0; i < len; i++) {
47 if (char_count == 3) {
48 pem[j++] = pem_enc[bits >> 18];
49 pem[j++] = pem_enc[(bits >> 12) & 0x3f];
50 pem[j++] = pem_enc[(bits >> 6) & 0x3f];
51 pem[j++] = pem_enc[bits & 0x3f];
59 if (char_count != 0) {
60 bits <<= 16 - (8 * char_count);
61 pem[j++] = pem_enc[bits >> 18];
62 pem[j++] = pem_enc[(bits >> 12) & 0x3f];
64 if (char_count == 1) {
68 pem[j++] = pem_enc[(bits >> 6) & 0x3f];
76 /* Same as above but puts newline ('\n') every 72 characters. */
78 char *silc_pem_encode_file(unsigned char *data, SilcUInt32 data_len)
84 pem = silc_pem_encode(data, data_len);
87 pem2 = silc_calloc(len + (len / 72) + 1, sizeof(*pem2));
89 for (i = 0, j = 0, cols = 1; i < len; i++, cols++) {
104 /* Decodes PEM into data. Returns the decoded data. */
106 unsigned char *silc_pem_decode(unsigned char *pem, SilcUInt32 pem_len,
110 SilcUInt32 len, c, char_count, bits;
112 static char ialpha[256], decoder[256];
114 for (i = 64 - 1; i >= 0; i--) {
115 ialpha[pem_enc[i]] = 1;
116 decoder[pem_enc[i]] = i;
128 data = silc_calloc(((len * 6) / 8), sizeof(*data));
130 for (i = 0; i < len; i++) {
136 if (c > 127 || !ialpha[c])
142 if (char_count == 4) {
143 data[j++] = bits >> 16;
144 data[j++] = (bits >> 8) & 0xff;
145 data[j++] = bits & 0xff;
159 data[j++] = bits >> 10;
162 data[j++] = bits >> 16;
163 data[j++] = (bits >> 8) & 0xff;
173 /* Concatenates the `src' into `dest'. If `src_len' is more than the
174 size of the `dest' (minus NULL at the end) the `src' will be
177 char *silc_strncat(char *dest, SilcUInt32 dest_size,
178 const char *src, SilcUInt32 src_len)
182 dest[dest_size - 1] = '\0';
184 len = dest_size - 1 - strlen(dest);
187 strncat(dest, src, len);
189 strncat(dest, src, src_len);