mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-11-26 13:25:42 +01:00
342 lines
9.6 KiB
C
342 lines
9.6 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 "base64_invasive.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 */
|
|
|
|
/* Return 0xff if low <= c <= high, 0 otherwise.
|
|
*
|
|
* Constant flow with respect to c.
|
|
*/
|
|
MBEDTLS_STATIC_TESTABLE
|
|
unsigned char mbedtls_base64_mask_of_range( unsigned char low,
|
|
unsigned char high,
|
|
unsigned char c )
|
|
{
|
|
/* low_mask is: 0 if low <= c, 0x...ff if low > c */
|
|
unsigned low_mask = ( (unsigned) c - low ) >> 8;
|
|
/* high_mask is: 0 if c <= high, 0x...ff if c > high */
|
|
unsigned high_mask = ( (unsigned) high - c ) >> 8;
|
|
return( ~( low_mask | high_mask ) & 0xff );
|
|
}
|
|
|
|
/* Given a value in the range 0..63, return the corresponding Base64 digit.
|
|
* The implementation assumes that letters are consecutive (e.g. ASCII
|
|
* but not EBCDIC).
|
|
*/
|
|
MBEDTLS_STATIC_TESTABLE
|
|
unsigned char mbedtls_base64_enc_char( unsigned char val )
|
|
{
|
|
unsigned char digit = 0;
|
|
/* For each range of values, if val is in that range, mask digit with
|
|
* the corresponding value. Since val can only be in a single range,
|
|
* only at most one masking will change digit. */
|
|
digit |= mbedtls_base64_mask_of_range( 0, 25, val ) & ( 'A' + val );
|
|
digit |= mbedtls_base64_mask_of_range( 26, 51, val ) & ( 'a' + val - 26 );
|
|
digit |= mbedtls_base64_mask_of_range( 52, 61, val ) & ( '0' + val - 52 );
|
|
digit |= mbedtls_base64_mask_of_range( 62, 62, val ) & '+';
|
|
digit |= mbedtls_base64_mask_of_range( 63, 63, val ) & '/';
|
|
return( digit );
|
|
}
|
|
|
|
/*
|
|
* 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_base64_enc_char( ( C1 >> 2 ) & 0x3F );
|
|
*p++ = mbedtls_base64_enc_char( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) )
|
|
& 0x3F );
|
|
*p++ = mbedtls_base64_enc_char( ( ( ( C2 & 15 ) << 2 ) + ( C3 >> 6 ) )
|
|
& 0x3F );
|
|
*p++ = mbedtls_base64_enc_char( C3 & 0x3F );
|
|
}
|
|
|
|
if( i < slen )
|
|
{
|
|
C1 = *src++;
|
|
C2 = ( ( i + 1 ) < slen ) ? *src++ : 0;
|
|
|
|
*p++ = mbedtls_base64_enc_char( ( C1 >> 2 ) & 0x3F );
|
|
*p++ = mbedtls_base64_enc_char( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) )
|
|
& 0x3F );
|
|
|
|
if( ( i + 1 ) < slen )
|
|
*p++ = mbedtls_base64_enc_char( ( ( C2 & 15 ) << 2 ) & 0x3F );
|
|
else *p++ = '=';
|
|
|
|
*p++ = '=';
|
|
}
|
|
|
|
*olen = p - dst;
|
|
*p = 0;
|
|
|
|
return( 0 );
|
|
}
|
|
|
|
/* Given a Base64 digit, return its value.
|
|
* If c is not a Base64 digit ('A'..'Z', 'a'..'z', '0'..'9', '+' or '/'),
|
|
* return -1.
|
|
*
|
|
* The implementation assumes that letters are consecutive (e.g. ASCII
|
|
* but not EBCDIC).
|
|
*
|
|
* The implementation is constant-flow (no branch or memory access depending
|
|
* on the value of c) unless the compiler inlines and optimizes a specific
|
|
* access.
|
|
*/
|
|
MBEDTLS_STATIC_TESTABLE
|
|
signed char mbedtls_base64_dec_value( unsigned char c )
|
|
{
|
|
unsigned char val = 0;
|
|
/* For each range of digits, if c is in that range, mask val with
|
|
* the corresponding value. Since c can only be in a single range,
|
|
* only at most one masking will change val. Set val to one plus
|
|
* the desired value so that it stays 0 if c is in none of the ranges. */
|
|
val |= mbedtls_base64_mask_of_range( 'A', 'Z', c ) & ( c - 'A' + 0 + 1 );
|
|
val |= mbedtls_base64_mask_of_range( 'a', 'z', c ) & ( c - 'a' + 26 + 1 );
|
|
val |= mbedtls_base64_mask_of_range( '0', '9', c ) & ( c - '0' + 52 + 1 );
|
|
val |= mbedtls_base64_mask_of_range( '+', '+', c ) & ( c - '+' + 62 + 1 );
|
|
val |= mbedtls_base64_mask_of_range( '/', '/', c ) & ( c - '/' + 63 + 1 );
|
|
/* At this point, val is 0 if c is an invalid digit and v+1 if c is
|
|
* a digit with the value v. */
|
|
return( val - 1 );
|
|
}
|
|
|
|
/*
|
|
* 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_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_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 */
|