1/*
2 * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
3 *
4 * This file is part of Libav.
5 *
6 * Libav 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 * Libav 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 Libav; 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
30/* ---------------- private code */
31static const uint8_t map2[] =
32{
33    0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
34    0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
35    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01,
36    0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
37    0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
38    0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
39    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
40    0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
41    0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
42    0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33
43};
44
45int av_base64_decode(uint8_t *out, const char *in, int out_size)
46{
47    int i, v;
48    uint8_t *dst = out;
49
50    v = 0;
51    for (i = 0; in[i] && in[i] != '='; i++) {
52        unsigned int index= in[i]-43;
53        if (index>=FF_ARRAY_ELEMS(map2) || map2[index] == 0xff)
54            return -1;
55        v = (v << 6) + map2[index];
56        if (i & 3) {
57            if (dst - out < out_size) {
58                *dst++ = v >> (6 - 2 * (i & 3));
59            }
60        }
61    }
62
63    return dst - out;
64}
65
66/*****************************************************************************
67* b64_encode: Stolen from VLC's http.c.
68* Simplified by Michael.
69* Fixed edge cases and made it work from data (vs. strings) by Ryan.
70*****************************************************************************/
71
72char *av_base64_encode(char *out, int out_size, const uint8_t *in, int in_size)
73{
74    static const char b64[] =
75        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
76    char *ret, *dst;
77    unsigned i_bits = 0;
78    int i_shift = 0;
79    int bytes_remaining = in_size;
80
81    if (in_size >= UINT_MAX / 4 ||
82        out_size < AV_BASE64_SIZE(in_size))
83        return NULL;
84    ret = dst = out;
85    while (bytes_remaining) {
86        i_bits = (i_bits << 8) + *in++;
87        bytes_remaining--;
88        i_shift += 8;
89
90        do {
91            *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
92            i_shift -= 6;
93        } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
94    }
95    while ((dst - ret) & 3)
96        *dst++ = '=';
97    *dst = '\0';
98
99    return ret;
100}
101
102#ifdef TEST
103
104#undef printf
105
106#define MAX_DATA_SIZE    1024
107#define MAX_ENCODED_SIZE 2048
108
109static int test_encode_decode(const uint8_t *data, unsigned int data_size,
110                              const char *encoded_ref)
111{
112    char  encoded[MAX_ENCODED_SIZE];
113    uint8_t data2[MAX_DATA_SIZE];
114    int data2_size, max_data2_size = MAX_DATA_SIZE;
115
116    if (!av_base64_encode(encoded, MAX_ENCODED_SIZE, data, data_size)) {
117        printf("Failed: cannot encode the input data\n");
118        return 1;
119    }
120    if (encoded_ref && strcmp(encoded, encoded_ref)) {
121        printf("Failed: encoded string differs from reference\n"
122               "Encoded:\n%s\nReference:\n%s\n", encoded, encoded_ref);
123        return 1;
124    }
125
126    if ((data2_size = av_base64_decode(data2, encoded, max_data2_size)) < 0) {
127        printf("Failed: cannot decode the encoded string\n"
128               "Encoded:\n%s\n", encoded);
129        return 1;
130    }
131    if (memcmp(data2, data, data_size)) {
132        printf("Failed: encoded/decoded data differs from original data\n");
133        return 1;
134    }
135
136    printf("Passed!\n");
137    return 0;
138}
139
140int main(void)
141{
142    int i, error_count = 0;
143    struct test {
144        const uint8_t *data;
145        const char *encoded_ref;
146    } tests[] = {
147        { "",        ""},
148        { "1",       "MQ=="},
149        { "22",      "MjI="},
150        { "333",     "MzMz"},
151        { "4444",    "NDQ0NA=="},
152        { "55555",   "NTU1NTU="},
153        { "666666",  "NjY2NjY2"},
154        { "abc:def", "YWJjOmRlZg=="},
155    };
156
157    printf("Encoding/decoding tests\n");
158    for (i = 0; i < FF_ARRAY_ELEMS(tests); i++)
159        error_count += test_encode_decode(tests[i].data, strlen(tests[i].data), tests[i].encoded_ref);
160
161    return error_count;
162}
163
164#endif
165