318 lines
8.4 KiB
C
318 lines
8.4 KiB
C
/*
|
|
* RFC 1521 base64 encoding/decoding
|
|
*
|
|
* Copyright The Mbed TLS Contributors
|
|
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
|
|
*
|
|
* This file is provided under the Apache License 2.0, or the
|
|
* GNU General Public License v2.0 or later.
|
|
*
|
|
* **********
|
|
* Apache License 2.0:
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
* not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* **********
|
|
*
|
|
* **********
|
|
* GNU General Public License v2.0 or later:
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program 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 General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* **********
|
|
*/
|
|
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_BASE64_C)
|
|
|
|
#include "mbedtls/base64.h"
|
|
|
|
#include <stdint.h>
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
#include <string.h>
|
|
#if defined(MBEDTLS_PLATFORM_C)
|
|
#include "mbedtls/platform.h"
|
|
#else
|
|
#include <stdio.h>
|
|
#define mbedtls_printf printf
|
|
#endif /* MBEDTLS_PLATFORM_C */
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
static const unsigned char base64_enc_map[64] =
|
|
{
|
|
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
|
|
'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
|
|
'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
|
|
'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
|
|
'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
|
|
'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
|
|
'8', '9', '+', '/'
|
|
};
|
|
|
|
static const unsigned char base64_dec_map[128] =
|
|
{
|
|
127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
|
|
127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
|
|
127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
|
|
127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
|
|
127, 127, 127, 62, 127, 127, 127, 63, 52, 53,
|
|
54, 55, 56, 57, 58, 59, 60, 61, 127, 127,
|
|
127, 64, 127, 127, 127, 0, 1, 2, 3, 4,
|
|
5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
|
|
15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
|
|
25, 127, 127, 127, 127, 127, 127, 26, 27, 28,
|
|
29, 30, 31, 32, 33, 34, 35, 36, 37, 38,
|
|
39, 40, 41, 42, 43, 44, 45, 46, 47, 48,
|
|
49, 50, 51, 127, 127, 127, 127, 127
|
|
};
|
|
|
|
#define BASE64_SIZE_T_MAX ( (size_t) -1 ) /* SIZE_T_MAX is not standard */
|
|
|
|
/*
|
|
* Encode a buffer into base64 format
|
|
*/
|
|
int mbedtls_base64_encode( unsigned char *dst, size_t dlen, size_t *olen,
|
|
const unsigned char *src, size_t slen )
|
|
{
|
|
size_t i, n;
|
|
int C1, C2, C3;
|
|
unsigned char *p;
|
|
|
|
if( slen == 0 )
|
|
{
|
|
*olen = 0;
|
|
return( 0 );
|
|
}
|
|
|
|
n = slen / 3 + ( slen % 3 != 0 );
|
|
|
|
if( n > ( BASE64_SIZE_T_MAX - 1 ) / 4 )
|
|
{
|
|
*olen = BASE64_SIZE_T_MAX;
|
|
return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
n *= 4;
|
|
|
|
if( ( dlen < n + 1 ) || ( NULL == dst ) )
|
|
{
|
|
*olen = n + 1;
|
|
return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
n = ( slen / 3 ) * 3;
|
|
|
|
for( i = 0, p = dst; i < n; i += 3 )
|
|
{
|
|
C1 = *src++;
|
|
C2 = *src++;
|
|
C3 = *src++;
|
|
|
|
*p++ = base64_enc_map[(C1 >> 2) & 0x3F];
|
|
*p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
|
|
*p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
|
|
*p++ = base64_enc_map[C3 & 0x3F];
|
|
}
|
|
|
|
if( i < slen )
|
|
{
|
|
C1 = *src++;
|
|
C2 = ( ( i + 1 ) < slen ) ? *src++ : 0;
|
|
|
|
*p++ = base64_enc_map[(C1 >> 2) & 0x3F];
|
|
*p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
|
|
|
|
if( ( i + 1 ) < slen )
|
|
*p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
|
|
else *p++ = '=';
|
|
|
|
*p++ = '=';
|
|
}
|
|
|
|
*olen = p - dst;
|
|
*p = 0;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/*
|
|
* Decode a base64-formatted buffer
|
|
*/
|
|
int mbedtls_base64_decode( unsigned char *dst, size_t dlen, size_t *olen,
|
|
const unsigned char *src, size_t slen )
|
|
{
|
|
size_t i, n;
|
|
uint32_t j, x;
|
|
unsigned char *p;
|
|
|
|
/* First pass: check for validity and get output length */
|
|
for( i = n = j = 0; i < slen; i++ )
|
|
{
|
|
/* Skip spaces before checking for EOL */
|
|
x = 0;
|
|
while( i < slen && src[i] == ' ' )
|
|
{
|
|
++i;
|
|
++x;
|
|
}
|
|
|
|
/* Spaces at end of buffer are OK */
|
|
if( i == slen )
|
|
break;
|
|
|
|
if( ( slen - i ) >= 2 &&
|
|
src[i] == '\r' && src[i + 1] == '\n' )
|
|
continue;
|
|
|
|
if( src[i] == '\n' )
|
|
continue;
|
|
|
|
/* Space inside a line is an error */
|
|
if( x != 0 )
|
|
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
|
|
|
|
if( src[i] == '=' && ++j > 2 )
|
|
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
|
|
|
|
if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
|
|
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
|
|
|
|
if( base64_dec_map[src[i]] < 64 && j != 0 )
|
|
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
|
|
|
|
n++;
|
|
}
|
|
|
|
if( n == 0 )
|
|
{
|
|
*olen = 0;
|
|
return( 0 );
|
|
}
|
|
|
|
/* The following expression is to calculate the following formula without
|
|
* risk of integer overflow in n:
|
|
* n = ( ( n * 6 ) + 7 ) >> 3;
|
|
*/
|
|
n = ( 6 * ( n >> 3 ) ) + ( ( 6 * ( n & 0x7 ) + 7 ) >> 3 );
|
|
n -= j;
|
|
|
|
if( dst == NULL || dlen < n )
|
|
{
|
|
*olen = n;
|
|
return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
|
|
}
|
|
|
|
for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
|
|
{
|
|
if( *src == '\r' || *src == '\n' || *src == ' ' )
|
|
continue;
|
|
|
|
j -= ( base64_dec_map[*src] == 64 );
|
|
x = ( x << 6 ) | ( base64_dec_map[*src] & 0x3F );
|
|
|
|
if( ++n == 4 )
|
|
{
|
|
n = 0;
|
|
if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
|
|
if( j > 1 ) *p++ = (unsigned char)( x >> 8 );
|
|
if( j > 2 ) *p++ = (unsigned char)( x );
|
|
}
|
|
}
|
|
|
|
*olen = p - dst;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#if defined(MBEDTLS_SELF_TEST)
|
|
|
|
static const unsigned char base64_test_dec[64] =
|
|
{
|
|
0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,
|
|
0xBF, 0x17, 0xD9, 0xA2, 0xC4, 0x17, 0x1A, 0x01,
|
|
0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, 0xD7, 0x09,
|
|
0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13,
|
|
0xCA, 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31,
|
|
0x6C, 0x08, 0x34, 0xFF, 0x8D, 0xC2, 0x6C, 0x38,
|
|
0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, 0x4B,
|
|
0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97
|
|
};
|
|
|
|
static const unsigned char base64_test_enc[] =
|
|
"JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK"
|
|
"swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw==";
|
|
|
|
/*
|
|
* Checkup routine
|
|
*/
|
|
int mbedtls_base64_self_test( int verbose )
|
|
{
|
|
size_t len;
|
|
const unsigned char *src;
|
|
unsigned char buffer[128];
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( " Base64 encoding test: " );
|
|
|
|
src = base64_test_dec;
|
|
|
|
if( mbedtls_base64_encode( buffer, sizeof( buffer ), &len, src, 64 ) != 0 ||
|
|
memcmp( base64_test_enc, buffer, 88 ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
return( 1 );
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n Base64 decoding test: " );
|
|
|
|
src = base64_test_enc;
|
|
|
|
if( mbedtls_base64_decode( buffer, sizeof( buffer ), &len, src, 88 ) != 0 ||
|
|
memcmp( base64_test_dec, buffer, 64 ) != 0 )
|
|
{
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "failed\n" );
|
|
|
|
return( 1 );
|
|
}
|
|
|
|
if( verbose != 0 )
|
|
mbedtls_printf( "passed\n\n" );
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
#endif /* MBEDTLS_SELF_TEST */
|
|
|
|
#endif /* MBEDTLS_BASE64_C */
|