1 /*
2 * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 /**
22 * @file
23 * @brief Base64 encode/decode
24 * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
25 */
26
27 #include <limits.h>
28 #include <stddef.h>
29
30 #include "base64.h"
31 #include "error.h"
32 #include "intreadwrite.h"
33
34 /* ---------------- private code */
35 static const uint8_t map2[256] =
36 {
37 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
38 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
39 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
40 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
41 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
42 0xff, 0xff, 0xff,
43
44 0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
45 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
46 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x01,
47 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
48 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
49 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
50 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
51 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
52 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
53 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,
54
55 0xff, 0xff, 0xff, 0xff, 0xff,
56 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
57 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
58 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
59 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
60 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
61 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
62 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
63 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
64 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
65 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
66 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
67 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
68 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
69 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
70 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
71 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
72 };
73
74 #define BASE64_DEC_STEP(i) do { \
75 bits = map2[in[i]]; \
76 if (bits & 0x80) \
77 goto out ## i; \
78 v = i ? (v << 6) + bits : bits; \
79 } while(0)
80
av_base64_decode(uint8_t * out,const char * in_str,int out_size)81 int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
82 {
83 uint8_t *dst = out;
84 uint8_t *end;
85 // no sign extension
86 const uint8_t *in = in_str;
87 unsigned bits = 0xff;
88 unsigned v;
89
90 if (!out)
91 goto validity_check;
92
93 end = out + out_size;
94 while (end - dst > 3) {
95 BASE64_DEC_STEP(0);
96 BASE64_DEC_STEP(1);
97 BASE64_DEC_STEP(2);
98 BASE64_DEC_STEP(3);
99 // Using AV_WB32 directly confuses compiler
100 v = av_be2ne32(v << 8);
101 AV_WN32(dst, v);
102 dst += 3;
103 in += 4;
104 }
105 if (end - dst) {
106 BASE64_DEC_STEP(0);
107 BASE64_DEC_STEP(1);
108 BASE64_DEC_STEP(2);
109 BASE64_DEC_STEP(3);
110 *dst++ = v >> 16;
111 if (end - dst)
112 *dst++ = v >> 8;
113 if (end - dst)
114 *dst++ = v;
115 in += 4;
116 }
117 validity_check:
118 while (1) {
119 BASE64_DEC_STEP(0);
120 in++;
121 BASE64_DEC_STEP(0);
122 in++;
123 BASE64_DEC_STEP(0);
124 in++;
125 BASE64_DEC_STEP(0);
126 in++;
127 }
128
129 out3:
130 *dst++ = v >> 10;
131 v <<= 2;
132 out2:
133 *dst++ = v >> 4;
134 out1:
135 out0:
136 return bits & 1 ? AVERROR_INVALIDDATA : out ? dst - out : 0;
137 }
138
139 /*****************************************************************************
140 * b64_encode: Stolen from VLC's http.c.
141 * Simplified by Michael.
142 * Fixed edge cases and made it work from data (vs. strings) by Ryan.
143 *****************************************************************************/
144
av_base64_encode(char * out,int out_size,const uint8_t * in,int in_size)145 char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
146 {
147 static const char b64[] =
148 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
149 char *ret, *dst;
150 unsigned i_bits = 0;
151 int i_shift = 0;
152 int bytes_remaining = in_size;
153
154 if (in_size >= UINT_MAX / 4 ||
155 out_size < AV_BASE64_SIZE(in_size))
156 return NULL;
157 ret = dst = out;
158 while (bytes_remaining > 3) {
159 i_bits = AV_RB32(in);
160 in += 3; bytes_remaining -= 3;
161 *dst++ = b64[ i_bits>>26 ];
162 *dst++ = b64[(i_bits>>20) & 0x3F];
163 *dst++ = b64[(i_bits>>14) & 0x3F];
164 *dst++ = b64[(i_bits>>8 ) & 0x3F];
165 }
166 i_bits = 0;
167 while (bytes_remaining) {
168 i_bits = (i_bits << 8) + *in++;
169 bytes_remaining--;
170 i_shift += 8;
171 }
172 while (i_shift > 0) {
173 *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
174 i_shift -= 6;
175 }
176 while ((dst - ret) & 3)
177 *dst++ = '=';
178 *dst = '\0';
179
180 return ret;
181 }
182