/* * 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 <limits.h>#include <stddef.h> #include "base64.h"#include "error.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;    // no sign extension    const uint8_t *in = in_str;    unsigned bits = 0xff;    unsigned v;     if (!out)        goto validity_check;     end = out + out_size;    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;    }validity_check:    while (1) {        BASE64_DEC_STEP(0);        in++;        BASE64_DEC_STEP(0);        in++;        BASE64_DEC_STEP(0);        in++;        BASE64_DEC_STEP(0);        in++;    } out3:    if (end - dst)        *dst++ = v >> 10;    v <<= 2;out2:    if (end - dst)        *dst++ = v >> 4;out1:out0:    return bits & 1 ? AVERROR_INVALIDDATA : out ? dst - out : 0;} /****************************************************************************** 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;}