Source code
Revision control
Copy as Markdown
Other Tools
/*
* 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:
*dst++ = v >> 10;
v <<= 2;
out2:
*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;
}