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path: root/libavutil/base64.c (plain)
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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 "common.h"
28#include "base64.h"
29#include "intreadwrite.h"
30#include "timer.h"
31
32/* ---------------- private code */
33static const uint8_t map2[256] =
34{
35 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
36 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
37 0xff, 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,
41
42 0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
43 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
44 0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x01,
45 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
46 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
47 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
48 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
49 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
50 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
51 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,
52
53 0xff, 0xff, 0xff, 0xff, 0xff,
54 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
55 0xff, 0xff, 0xff, 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};
71
72#define BASE64_DEC_STEP(i) do { \
73 bits = map2[in[i]]; \
74 if (bits & 0x80) \
75 goto out ## i; \
76 v = i ? (v << 6) + bits : bits; \
77} while(0)
78
79int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
80{
81 uint8_t *dst = out;
82 uint8_t *end = out + out_size;
83 // no sign extension
84 const uint8_t *in = in_str;
85 unsigned bits = 0xff;
86 unsigned v;
87
88 while (end - dst > 3) {
89 BASE64_DEC_STEP(0);
90 BASE64_DEC_STEP(1);
91 BASE64_DEC_STEP(2);
92 BASE64_DEC_STEP(3);
93 // Using AV_WB32 directly confuses compiler
94 v = av_be2ne32(v << 8);
95 AV_WN32(dst, v);
96 dst += 3;
97 in += 4;
98 }
99 if (end - dst) {
100 BASE64_DEC_STEP(0);
101 BASE64_DEC_STEP(1);
102 BASE64_DEC_STEP(2);
103 BASE64_DEC_STEP(3);
104 *dst++ = v >> 16;
105 if (end - dst)
106 *dst++ = v >> 8;
107 if (end - dst)
108 *dst++ = v;
109 in += 4;
110 }
111 while (1) {
112 BASE64_DEC_STEP(0);
113 in++;
114 BASE64_DEC_STEP(0);
115 in++;
116 BASE64_DEC_STEP(0);
117 in++;
118 BASE64_DEC_STEP(0);
119 in++;
120 }
121
122out3:
123 *dst++ = v >> 10;
124 v <<= 2;
125out2:
126 *dst++ = v >> 4;
127out1:
128out0:
129 return bits & 1 ? AVERROR_INVALIDDATA : dst - out;
130}
131
132/*****************************************************************************
133* b64_encode: Stolen from VLC's http.c.
134* Simplified by Michael.
135* Fixed edge cases and made it work from data (vs. strings) by Ryan.
136*****************************************************************************/
137
138char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
139{
140 static const char b64[] =
141 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
142 char *ret, *dst;
143 unsigned i_bits = 0;
144 int i_shift = 0;
145 int bytes_remaining = in_size;
146
147 if (in_size >= UINT_MAX / 4 ||
148 out_size < AV_BASE64_SIZE(in_size))
149 return NULL;
150 ret = dst = out;
151 while (bytes_remaining > 3) {
152 i_bits = AV_RB32(in);
153 in += 3; bytes_remaining -= 3;
154 *dst++ = b64[ i_bits>>26 ];
155 *dst++ = b64[(i_bits>>20) & 0x3F];
156 *dst++ = b64[(i_bits>>14) & 0x3F];
157 *dst++ = b64[(i_bits>>8 ) & 0x3F];
158 }
159 i_bits = 0;
160 while (bytes_remaining) {
161 i_bits = (i_bits << 8) + *in++;
162 bytes_remaining--;
163 i_shift += 8;
164 }
165 while (i_shift > 0) {
166 *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
167 i_shift -= 6;
168 }
169 while ((dst - ret) & 3)
170 *dst++ = '=';
171 *dst = '\0';
172
173 return ret;
174}
175
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