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/*
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 * Copyright (c) 2006 Ryan Martell. (rdm4@martellventures.com)
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file base64.c
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 * @brief Base64 encode/decode
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 * @author Ryan Martell <rdm4@martellventures.com> (with lots of Michael)
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 */
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#include "common.h"
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#include "base64.h"
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/* ---------------- private code */
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static const uint8_t map2[] =
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{
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    0x3e, 0xff, 0xff, 0xff, 0x3f, 0x34, 0x35, 0x36,
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    0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0xff,
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    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x01,
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    0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
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    0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11,
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    0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
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    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x1a, 0x1b,
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    0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23,
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    0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b,
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    0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33
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};
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int av_base64_decode(uint8_t * out, const char *in, int out_length)
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{
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    int i, v;
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    uint8_t *dst = out;
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    v = 0;
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    for (i = 0; in[i] && in[i] != '='; i++) {
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        unsigned int index= in[i]-43;
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        if (index>=FF_ARRAY_ELEMS(map2) || map2[index] == 0xff)
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            return -1;
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        v = (v << 6) + map2[index];
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        if (i & 3) {
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            if (dst - out < out_length) {
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                *dst++ = v >> (6 - 2 * (i & 3));
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            }
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        }
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    }
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    return dst - out;
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}
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/*****************************************************************************
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* b64_encode: Stolen from VLC's http.c.
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* Simplified by Michael.
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* Fixed edge cases and made it work from data (vs. strings) by Ryan.
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*****************************************************************************/
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char *av_base64_encode(char * buf, int buf_len, const uint8_t * src, int len)
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{
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    static const char b64[] =
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        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
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    char *ret, *dst;
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    unsigned i_bits = 0;
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    int i_shift = 0;
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    int bytes_remaining = len;
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    if (len >= UINT_MAX / 4 ||
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        buf_len < len * 4 / 3 + 12)
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        return NULL;
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    ret = dst = buf;
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    while (bytes_remaining) {
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        i_bits = (i_bits << 8) + *src++;
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        bytes_remaining--;
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        i_shift += 8;
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        do {
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            *dst++ = b64[(i_bits << 6 >> i_shift) & 0x3f];
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            i_shift -= 6;
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        } while (i_shift > 6 || (bytes_remaining == 0 && i_shift > 0));
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    }
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    while ((dst - ret) & 3)
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        *dst++ = '=';
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    *dst = '\0';
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    return ret;
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}
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#ifdef TEST
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#include "log.h"
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#include "mem.h"
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int main(void)
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{
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    int numerr = 0;
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    int len;
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    int numtest = 1;
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    uint8_t decode[1000];
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    struct test {
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        void *data;
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        int len;
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        const char *result;
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    } *t, tests[] = {
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        {
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        "", 0, ""}, {
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        "1", 1, "MQ=="}, {
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        "22", 2, "MjI="}, {
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        "333", 3, "MzMz"}, {
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        "4444", 4, "NDQ0NA=="}, {
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        "55555", 5, "NTU1NTU="}, {
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        "abc:def", 7, "YWJjOmRlZg=="}, {
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        NULL}
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    };
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    for (t = tests; t->data; t++) {
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        char *str;
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        av_log(NULL, AV_LOG_ERROR, "Encoding %s...\n", (char *) t->data);
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        str = av_base64_encode(t->data, t->len);
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        if (str) {
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            av_log(NULL, AV_LOG_ERROR, "Encoded to %s...\n", str);
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            if (strcmp(str, t->result) != 0) {
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                av_log(NULL, AV_LOG_ERROR, "failed test %d: %s != %s\n",
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                       numtest, str, t->result);
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                numerr++;
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            }
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            av_free(str);
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        }
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        av_log(NULL, AV_LOG_ERROR, "Done encoding, about to decode...\n");
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        len = av_base64_decode(decode, t->result, sizeof(decode));
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        if (len != t->len) {
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            av_log(NULL, AV_LOG_ERROR, "failed test %d: len %d != %d\n",
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                   numtest, len, t->len);
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            numerr++;
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        } else if (memcmp(decode, t->data, t->len) != 0) {
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            av_log(NULL, AV_LOG_ERROR, "failed test %d: data\n", numtest);
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            numerr++;
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        } else {
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            av_log(NULL, AV_LOG_ERROR, "Decoded to %s\n",
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                   (char *) t->data);
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        }
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        numtest++;
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    }
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#undef srand
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#undef rand
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    {
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        int test_count;
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        srand(123141);          // time(NULL));
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        for (test_count = 0; test_count < 100; test_count++) {
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            int size = rand() % 1024;
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            int ii;
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            uint8_t *data;
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            char *encoded_result;
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            av_log(NULL, AV_LOG_ERROR, "Test %d: Size %d bytes...",
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                   test_count, size);
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            data = (uint8_t *) av_malloc(size);
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            for (ii = 0; ii < size; ii++) {
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                data[ii] = rand() % 255;
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            }
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            encoded_result = av_base64_encode(data, size);
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            if (encoded_result) {
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                int decode_buffer_size = size + 10;     // try without 10 as well
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                uint8_t *decode_buffer = av_malloc(decode_buffer_size);
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                if (decode_buffer) {
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                    int decoded_size =
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                        av_base64_decode(decode_buffer, encoded_result,
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                                   decode_buffer_size);
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                    if (decoded_size != size) {
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                        av_log(NULL, AV_LOG_ERROR,
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                               "Decoded/Encoded size mismatch (%d != %d)\n",
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                               decoded_size, size);
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                    } else {
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                        if (memcmp(decode_buffer, data, decoded_size) == 0) {
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                            av_log(NULL, AV_LOG_ERROR, "Passed!\n");
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                        } else {
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                            av_log(NULL, AV_LOG_ERROR,
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                                   "Failed (Data differs)!\n");
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                        }
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                    }
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                    av_free(decode_buffer);
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                }
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                av_free(encoded_result);
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            }
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        }
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    }
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    // these are invalid strings, that it currently decodes (which it probably shouldn't?)
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    {
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        uint8_t str[32];
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        if (av_base64_decode(str, "M=M=", sizeof(str)) != -1) {
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            av_log(NULL, AV_LOG_ERROR,
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                   "failed test %d: successful decode of `M=M='\n",
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                   numtest++);
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            numerr++;
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        }
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        if (av_base64_decode(str, "MQ===", sizeof(str)) != -1) {
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            av_log(NULL, AV_LOG_ERROR,
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                   "failed test %d: successful decode of `MQ==='\n",
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                   numtest++);
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            numerr++;
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        }
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    }
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    return numerr;
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}
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#endif
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