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
176#ifdef TEST
177// LCOV_EXCL_START
178
179#define MAX_DATA_SIZE    1024
180#define MAX_ENCODED_SIZE 2048
181
182static int test_encode_decode(const uint8_t *data, unsigned int data_size,
183                              const char *encoded_ref)
184{
185    char  encoded[MAX_ENCODED_SIZE];
186    uint8_t data2[MAX_DATA_SIZE];
187    int data2_size, max_data2_size = MAX_DATA_SIZE;
188
189    if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
190        printf("Failed: cannot encode the input data\n");
191        return 1;
192    }
193    if (encoded_ref && strcmp(encoded, encoded_ref)) {
194        printf("Failed: encoded string differs from reference\n"
195               "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
196        return 1;
197    }
198
199    if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) != data_size) {
200        printf("Failed: cannot decode the encoded string\n"
201               "Encoded:\n%s\n", encoded);
202        return 1;
203    }
204    if ((data2_size = av_base64_decode(data2, encoded, data_size)) != data_size) {
205        printf("Failed: cannot decode with minimal buffer\n"
206               "Encoded:\n%s\n", encoded);
207        return 1;
208    }
209    if (memcmp(data2, data, data_size)) {
210        printf("Failed: encoded/decoded data differs from original data\n");
211        return 1;
212    }
213    if (av_base64_decode(NULL, encoded, 0) != 0) {
214        printf("Failed: decode to NULL buffer\n");
215        return 1;
216    }
217    if (strlen(encoded)) {
218        char *end = strchr(encoded, '=');
219        if (!end)
220            end = encoded + strlen(encoded) - 1;
221        *end = '%';
222        if (av_base64_decode(NULL, encoded, 0) >= 0) {
223            printf("Failed: error detection\n");
224            return 1;
225        }
226    }
227
228    printf("Passed!\n");
229    return 0;
230}
231
232int main(int argc, char ** argv)
233{
234    int i, error_count = 0;
235    struct test {
236        const uint8_t *data;
237        const char *encoded_ref;
238    } tests[] = {
239        { "",        ""},
240        { "1",       "MQ=="},
241        { "22",      "MjI="},
242        { "333",     "MzMz"},
243        { "4444",    "NDQ0NA=="},
244        { "55555",   "NTU1NTU="},
245        { "666666",  "NjY2NjY2"},
246        { "abc:def", "YWJjOmRlZg=="},
247    };
248    char in[1024], out[2048];
249
250    printf("Encoding/decoding tests\n");
251    for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
252        error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);
253
254    if (argc>1 && !strcmp(argv[1], "-t")) {
255        memset(in, 123, sizeof(in));
256        for(i=0; i<10000; i++){
257            START_TIMER
258            av_base64_encode(out, sizeof(out), in, sizeof(in));
259            STOP_TIMER("encode")
260        }
261        for(i=0; i<10000; i++){
262            START_TIMER
263            av_base64_decode(in, out, sizeof(in));
264            STOP_TIMER("decode")
265        }
266
267        for(i=0; i<10000; i++){
268            START_TIMER
269            av_base64_decode(NULL, out, 0);
270            STOP_TIMER("syntax check")
271        }
272    }
273
274    if (error_count)
275        printf("Error Count: %d.\n", error_count);
276
277    return !!error_count;
278}
279
280// LCOV_EXCL_STOP
281#endif
282