FFmpeg
base64.c
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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 <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 
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 
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 }
out
FILE * out
Definition: movenc.c:54
out_size
int out_size
Definition: movenc.c:55
intreadwrite.h
bits
uint8_t bits
Definition: vp3data.h:141
limits.h
av_be2ne32
#define av_be2ne32(x)
Definition: bswap.h:95
NULL
#define NULL
Definition: coverity.c:32
map2
static const uint8_t map2[256]
Definition: base64.c:35
av_base64_decode
int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
Decode a base64-encoded string.
Definition: base64.c:81
base64.h
error.h
AV_WN32
#define AV_WN32(p, v)
Definition: intreadwrite.h:376
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
AV_BASE64_SIZE
#define AV_BASE64_SIZE(x)
Calculate the output size needed to base64-encode x bytes to a null-terminated string.
Definition: base64.h:66
ret
ret
Definition: filter_design.txt:187
av_base64_encode
char * av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
Encode data to base64 and null-terminate.
Definition: base64.c:145
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
BASE64_DEC_STEP
#define BASE64_DEC_STEP(i)
Definition: base64.c:74