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 "common.h"
28 #include "base64.h"
29 #include "intreadwrite.h"
30 #include "timer.h"
31 
32 /* ---------------- private code */
33 static 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 
79 int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
80 {
81  uint8_t *dst = out;
82  uint8_t *end;
83  // no sign extension
84  const uint8_t *in = in_str;
85  unsigned bits = 0xff;
86  unsigned v;
87 
88  if (!out)
89  goto validity_check;
90 
91  end = out + out_size;
92  while (end - dst > 3) {
93  BASE64_DEC_STEP(0);
94  BASE64_DEC_STEP(1);
95  BASE64_DEC_STEP(2);
96  BASE64_DEC_STEP(3);
97  // Using AV_WB32 directly confuses compiler
98  v = av_be2ne32(v << 8);
99  AV_WN32(dst, v);
100  dst += 3;
101  in += 4;
102  }
103  if (end - dst) {
104  BASE64_DEC_STEP(0);
105  BASE64_DEC_STEP(1);
106  BASE64_DEC_STEP(2);
107  BASE64_DEC_STEP(3);
108  *dst++ = v >> 16;
109  if (end - dst)
110  *dst++ = v >> 8;
111  if (end - dst)
112  *dst++ = v;
113  in += 4;
114  }
115 validity_check:
116  while (1) {
117  BASE64_DEC_STEP(0);
118  in++;
119  BASE64_DEC_STEP(0);
120  in++;
121  BASE64_DEC_STEP(0);
122  in++;
123  BASE64_DEC_STEP(0);
124  in++;
125  }
126 
127 out3:
128  *dst++ = v >> 10;
129  v <<= 2;
130 out2:
131  *dst++ = v >> 4;
132 out1:
133 out0:
134  return bits & 1 ? AVERROR_INVALIDDATA : out ? dst - out : 0;
135 }
136 
137 /*****************************************************************************
138 * b64_encode: Stolen from VLC's http.c.
139 * Simplified by Michael.
140 * Fixed edge cases and made it work from data (vs. strings) by Ryan.
141 *****************************************************************************/
142 
143 char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
144 {
145  static const char b64[] =
146  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
147  char *ret, *dst;
148  unsigned i_bits = 0;
149  int i_shift = 0;
150  int bytes_remaining = in_size;
151 
152  if (in_size >= UINT_MAX / 4 ||
153  out_size < AV_BASE64_SIZE(in_size))
154  return NULL;
155  ret = dst = out;
156  while (bytes_remaining > 3) {
157  i_bits = AV_RB32(in);
158  in += 3; bytes_remaining -= 3;
159  *dst++ = b64[ i_bits>>26 ];
160  *dst++ = b64[(i_bits>>20) & 0x3F];
161  *dst++ = b64[(i_bits>>14) & 0x3F];
162  *dst++ = b64[(i_bits>>8 ) & 0x3F];
163  }
164  i_bits = 0;
165  while (bytes_remaining) {
166  i_bits = (i_bits << 8) + *in++;
167  bytes_remaining--;
168  i_shift += 8;
169  }
170  while (i_shift > 0) {
171  *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
172  i_shift -= 6;
173  }
174  while ((dst - ret) & 3)
175  *dst++ = '=';
176  *dst = '\0';
177 
178  return ret;
179 }
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
av_be2ne32
#define av_be2ne32(x)
Definition: bswap.h:93
NULL
#define NULL
Definition: coverity.c:32
map2
static const uint8_t map2[256]
Definition: base64.c:33
timer.h
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:79
base64.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
common.h
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:143
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
BASE64_DEC_STEP
#define BASE64_DEC_STEP(i)
Definition: base64.c:72