virtualx-engine/thirdparty/mbedtls/library/base64.c
Fabio Alessandrelli d76a26e086
Bump mbedTLS version to 2.28.0 (new LTS).
Keep applying the windows entropy patch (UWP support).
Remove no longer needed padlock patch.
Update thirdparty README to reflect changes, and new source inclusion
criteria.

(cherry picked from commit e375cbd094)
2022-01-19 14:03:03 +01:00

277 lines
6.9 KiB
C

/*
* RFC 1521 base64 encoding/decoding
*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-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.
*/
#include "common.h"
#if defined(MBEDTLS_BASE64_C)
#include "mbedtls/base64.h"
#include "constant_time_internal.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 */
#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++ = mbedtls_ct_base64_enc_char( ( C1 >> 2 ) & 0x3F );
*p++ = mbedtls_ct_base64_enc_char( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) )
& 0x3F );
*p++ = mbedtls_ct_base64_enc_char( ( ( ( C2 & 15 ) << 2 ) + ( C3 >> 6 ) )
& 0x3F );
*p++ = mbedtls_ct_base64_enc_char( C3 & 0x3F );
}
if( i < slen )
{
C1 = *src++;
C2 = ( ( i + 1 ) < slen ) ? *src++ : 0;
*p++ = mbedtls_ct_base64_enc_char( ( C1 >> 2 ) & 0x3F );
*p++ = mbedtls_ct_base64_enc_char( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) )
& 0x3F );
if( ( i + 1 ) < slen )
*p++ = mbedtls_ct_base64_enc_char( ( ( 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; /* index in source */
size_t n; /* number of digits or trailing = in source */
uint32_t x; /* value accumulator */
unsigned accumulated_digits = 0;
unsigned equals = 0;
int spaces_present = 0;
unsigned char *p;
/* First pass: check for validity and get output length */
for( i = n = 0; i < slen; i++ )
{
/* Skip spaces before checking for EOL */
spaces_present = 0;
while( i < slen && src[i] == ' ' )
{
++i;
spaces_present = 1;
}
/* 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( spaces_present )
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
if( src[i] > 127 )
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
if( src[i] == '=' )
{
if( ++equals > 2 )
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
}
else
{
if( equals != 0 )
return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER );
if( mbedtls_ct_base64_dec_value( src[i] ) < 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 -= equals;
if( dst == NULL || dlen < n )
{
*olen = n;
return( MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL );
}
equals = 0;
for( x = 0, p = dst; i > 0; i--, src++ )
{
if( *src == '\r' || *src == '\n' || *src == ' ' )
continue;
x = x << 6;
if( *src == '=' )
++equals;
else
x |= mbedtls_ct_base64_dec_value( *src );
if( ++accumulated_digits == 4 )
{
accumulated_digits = 0;
*p++ = MBEDTLS_BYTE_2( x );
if( equals <= 1 ) *p++ = MBEDTLS_BYTE_1( x );
if( equals <= 0 ) *p++ = MBEDTLS_BYTE_0( 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 */