aboutsummaryrefslogtreecommitdiffstats
path: root/libavutil/base64.c
blob: 87e2dfd9819b36c0c35ec5705568a0b7df32a727 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
/*
 * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * @brief Base64 encode/decode
 * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
 */

#include "common.h"
#include "base64.h"
#include "intreadwrite.h"

/* ---------------- private code */
static const uint8_t map2[256] =
{
    0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff,

    0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
    0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
    0xff, 0xff, 0xfe, 0xff, 0xff, 0xff, 0x00, 0x01,
    0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
    0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
    0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
    0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
    0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
    0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33,

                      0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
};

#define BASE64_DEC_STEP(i) do { \
    bits = map2[in[i]]; \
    if (bits & 0x80) \
        goto out ## i; \
    v = i ? (v << 6) + bits : bits; \
} while(0)

int av_base64_decode(uint8_t *out, const char *in_str, int out_size)
{
    uint8_t *dst = out;
    uint8_t *end = out + out_size;
    // no sign extension
    const uint8_t *in = in_str;
    unsigned bits = 0xff;
    unsigned v;

    while (end - dst > 3) {
        BASE64_DEC_STEP(0);
        BASE64_DEC_STEP(1);
        BASE64_DEC_STEP(2);
        BASE64_DEC_STEP(3);
        // Using AV_WB32 directly confuses compiler
        v = av_be2ne32(v << 8);
        AV_WN32(dst, v);
        dst += 3;
        in += 4;
    }
    if (end - dst) {
        BASE64_DEC_STEP(0);
        BASE64_DEC_STEP(1);
        BASE64_DEC_STEP(2);
        BASE64_DEC_STEP(3);
        *dst++ = v >> 16;
        if (end - dst)
            *dst++ = v >> 8;
        if (end - dst)
            *dst++ = v;
        in += 4;
    }
    while (1) {
        BASE64_DEC_STEP(0);
        in++;
        BASE64_DEC_STEP(0);
        in++;
        BASE64_DEC_STEP(0);
        in++;
        BASE64_DEC_STEP(0);
        in++;
    }

out3:
    *dst++ = v >> 10;
    v <<= 2;
out2:
    *dst++ = v >> 4;
out1:
out0:
    return bits & 1 ? AVERROR_INVALIDDATA : dst - out;
}

/*****************************************************************************
* b64_encode: Stolen from VLC's http.c.
* Simplified by Michael.
* Fixed edge cases and made it work from data (vs. strings) by Ryan.
*****************************************************************************/

char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
{
    static const char b64[] =
        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
    char *ret, *dst;
    unsigned i_bits = 0;
    int i_shift = 0;
    int bytes_remaining = in_size;

    if (in_size >= UINT_MAX / 4 ||
        out_size < AV_BASE64_SIZE(in_size))
        return NULL;
    ret = dst = out;
    while (bytes_remaining > 3) {
        i_bits = AV_RB32(in);
        in += 3; bytes_remaining -= 3;
        *dst++ = b64[ i_bits>>26        ];
        *dst++ = b64[(i_bits>>20) & 0x3F];
        *dst++ = b64[(i_bits>>14) & 0x3F];
        *dst++ = b64[(i_bits>>8 ) & 0x3F];
    }
    i_bits = 0;
    while (bytes_remaining) {
        i_bits = (i_bits << 8) + *in++;
        bytes_remaining--;
        i_shift += 8;
    }
    while (i_shift > 0) {
        *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
        i_shift -= 6;
    }
    while ((dst - ret) & 3)
        *dst++ = '=';
    *dst = '\0';

    return ret;
}

#ifdef TEST
// LCOV_EXCL_START

#define MAX_DATA_SIZE    1024
#define MAX_ENCODED_SIZE 2048

static int test_encode_decode(const uint8_t *data, unsigned int data_size,
                              const char *encoded_ref)
{
    char  encoded[MAX_ENCODED_SIZE];
    uint8_t data2[MAX_DATA_SIZE];
    int data2_size, max_data2_size = MAX_DATA_SIZE;

    if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
        printf("Failed: cannot encode the input data\n");
        return 1;
    }
    if (encoded_ref && strcmp(encoded, encoded_ref)) {
        printf("Failed: encoded string differs from reference\n"
               "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
        return 1;
    }

    if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) != data_size) {
        printf("Failed: cannot decode the encoded string\n"
               "Encoded:\n%s\n", encoded);
        return 1;
    }
    if ((data2_size = av_base64_decode(data2, encoded, data_size)) != data_size) {
        printf("Failed: cannot decode with minimal buffer\n"
               "Encoded:\n%s\n", encoded);
        return 1;
    }
    if (memcmp(data2, data, data_size)) {
        printf("Failed: encoded/decoded data differs from original data\n");
        return 1;
    }
    if (av_base64_decode(NULL, encoded, 0) != 0) {
        printf("Failed: decode to NULL buffer\n");
        return 1;
    }
    if (strlen(encoded)) {
        char *end = strchr(encoded, '=');
        if (!end)
            end = encoded + strlen(encoded) - 1;
        *end = '%';
        if (av_base64_decode(NULL, encoded, 0) >= 0) {
            printf("Failed: error detection\n");
            return 1;
        }
    }

    printf("Passed!\n");
    return 0;
}

int main(int argc, char ** argv)
{
    int i, error_count = 0;
    struct test {
        const uint8_t *data;
        const char *encoded_ref;
    } tests[] = {
        { "",        ""},
        { "1",       "MQ=="},
        { "22",      "MjI="},
        { "333",     "MzMz"},
        { "4444",    "NDQ0NA=="},
        { "55555",   "NTU1NTU="},
        { "666666",  "NjY2NjY2"},
        { "abc:def", "YWJjOmRlZg=="},
    };
    char in[1024], out[2048];

    printf("Encoding/decoding tests\n");
    for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
        error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);

    if (argc>1 && !strcmp(argv[1], "-t")) {
        memset(in, 123, sizeof(in));
        for(i=0; i<10000; i++){
            START_TIMER
            av_base64_encode(out, sizeof(out), in, sizeof(in));
            STOP_TIMER("encode")
        }
        for(i=0; i<10000; i++){
            START_TIMER
            av_base64_decode(in, out, sizeof(in));
            STOP_TIMER("decode")
        }

        for(i=0; i<10000; i++){
            START_TIMER
            av_base64_decode(NULL, out, 0);
            STOP_TIMER("syntax check")
        }
    }

    return error_count;
}

// LCOV_EXCL_STOP
#endif