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view src/base64/base64.c @ 321:412385b57dc4

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refactoring
author meillo@marmaro.de
date Thu, 28 Apr 2011 16:48:23 +0200
parents 589c365d90b1
children 41958685480d
line source
1 /* base64.c, Copyright 2000 (C) Oliver Kurth,
2 *
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program; if not, write to the Free Software
15 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 */
17
18 /* see also RFC 1341 */
19
20 #include <glib.h>
21 #include <string.h>
22 #include "base64.h"
23
24 gchar*
25 base64_encode(guchar * buf, gint len)
26 {
27 guchar *outbuf, *q;
28 gchar enc[64];
29 gint i = 0, j = 0;
30 guint in0, in1, in2;
31
32 for (; i < 26; i++)
33 enc[i] = (gchar) ('A' + j++);
34 j = 0;
35 for (; i < 52; i++)
36 enc[i] = (gchar) ('a' + j++);
37 j = 0;
38 for (; i < 62; i++)
39 enc[i] = (gchar) ('0' + j++);
40 enc[i++] = '+';
41 enc[i++] = '/';
42
43 outbuf = g_malloc(((len + 3) * 8) / 6 +1);
44 memset(outbuf, 0, ((len + 3) * 8) / 6 +1);
45 q = outbuf;
46
47 i = 0;
48 while (i < len - 2) {
49 in0 = buf[i++];
50 in1 = buf[i++];
51 in2 = buf[i++];
52
53 *(q++) = enc[(in0 >> 2) & 0x3f];
54 *(q++) = enc[((in0 << 4) | (in1 >> 4)) & 0x3f];
55 *(q++) = enc[((in1 << 2) | (in2 >> 6)) & 0x3f];
56 *(q++) = enc[in2 & 0x3f];
57 }
58 if ((len - i) == 1) {
59 in0 = buf[i++];
60 *(q++) = enc[(in0 >> 2) & 0x3f];
61 *(q++) = enc[(in0 << 4) & 0x3f];
62 *(q++) = '=';
63 *(q++) = '=';
64 } else if ((len - i) == 2) {
65 in0 = buf[i++];
66 in1 = buf[i++];
67 *(q++) = enc[(in0 >> 2) & 0x3f];
68 *(q++) = enc[((in0 << 4) | (in1 >> 4)) & 0x3f];
69 *(q++) = enc[(in1 << 2) & 0x3f];
70 *(q++) = '=';
71 }
72 *q = 0;
73
74 return outbuf;
75 }
76
77 gchar *base64_decode(gchar * buf, gint * size)
78 {
79 guchar *p = buf, *q;
80 guint in[4];
81 /* gchar *out = g_malloc(((strlen(buf)+3) * 3) / 4 + 1); */
82 gchar *out = g_malloc((strlen(buf) + 3) + 1 +1);
83 memset(out, 0, (strlen(buf) + 3) + 1 +1);
84
85 q = out;
86 *size = 0;
87
88 *q = 0;
89
90 while (*p) {
91 int i = 0;
92 while (i < 4) {
93 if (!*p)
94 break;
95 if ((*p >= 'A') && (*p <= 'Z'))
96 in[i++] = *p - 'A';
97 else if ((*p >= 'a') && (*p <= 'z'))
98 in[i++] = (*p - 'a') + 26;
99 else if ((*p >= '0') && (*p <= '9'))
100 in[i++] = (*p - '0') + 52;
101 else if (*p == '+')
102 in[i++] = 62;
103 else if (*p == '/')
104 in[i++] = 63;
105 else if (*p == '=') {
106 in[i++] = 0;
107 p++;
108 break;
109 } else if ((*p != '\r') && (*p != '\n')) {
110 p++;
111 break;
112 }
113 p++;
114 }
115 if ((i == 4) || (p[-1] == '=')) {
116 *(q++) = ((in[0] << 2) | (in[1] >> 4));
117 *(q++) = ((in[1] << 4) | (in[2] >> 2));
118 *(q++) = ((in[2] << 6) | in[3]);
119 if (p[-1] == '=') {
120 if (i == 3) {
121 (*size)++;
122 } else if (i == 4) {
123 (*size) += 2;
124 }
125 } else {
126 *size += 3;
127 }
128 }
129 }
130 out[*size] = '\0';
131 return out;
132 }