| /* |
| * 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 <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 */ |
| |
| /* |
| * Constant flow conditional assignment to unsigned char |
| */ |
| static void mbedtls_base64_cond_assign_uchar(unsigned char * dest, const unsigned char * const src, |
| unsigned char condition) |
| { |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| #if defined(_MSC_VER) |
| #pragma warning( push ) |
| #pragma warning( disable : 4146 ) |
| #endif |
| |
| /* Generate bitmask from condition, mask will either be 0xFFFFFFFF or 0 */ |
| unsigned char mask = ( condition | -condition ); |
| mask >>= 7; |
| mask = -mask; |
| |
| #if defined(_MSC_VER) |
| #pragma warning( pop ) |
| #endif |
| |
| *dest = ( ( *src ) & mask ) | ( ( *dest ) & ~mask ); |
| } |
| |
| /* |
| * Constant flow conditional assignment to uint_32 |
| */ |
| static void mbedtls_base64_cond_assign_uint32(uint32_t * dest, const uint32_t src, |
| uint32_t condition) |
| { |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| #if defined(_MSC_VER) |
| #pragma warning( push ) |
| #pragma warning( disable : 4146 ) |
| #endif |
| |
| /* Generate bitmask from condition, mask will either be 0xFFFFFFFF or 0 */ |
| uint32_t mask = ( condition | -condition ); |
| mask >>= 31; |
| mask = -mask; |
| |
| #if defined(_MSC_VER) |
| #pragma warning( pop ) |
| #endif |
| |
| *dest = ( src & mask ) | ( ( *dest ) & ~mask ); |
| } |
| |
| /* |
| * Constant flow check for equality |
| */ |
| static unsigned char mbedtls_base64_eq(size_t in_a, size_t in_b) |
| { |
| size_t difference = in_a ^ in_b; |
| |
| /* MSVC has a warning about unary minus on unsigned integer types, |
| * but this is well-defined and precisely what we want to do here. */ |
| #if defined(_MSC_VER) |
| #pragma warning( push ) |
| #pragma warning( disable : 4146 ) |
| #endif |
| |
| difference |= -difference; |
| |
| #if defined(_MSC_VER) |
| #pragma warning( pop ) |
| #endif |
| |
| /* cope with the varying size of size_t per platform */ |
| difference >>= ( sizeof( difference ) * 8 - 1 ); |
| |
| return (unsigned char) ( 1 ^ difference ); |
| } |
| |
| /* |
| * Constant flow lookup into table. |
| */ |
| static unsigned char mbedtls_base64_table_lookup(const unsigned char * const table, |
| const size_t table_size, const size_t table_index) |
| { |
| size_t i; |
| unsigned char result = 0; |
| |
| for( i = 0; i < table_size; ++i ) |
| { |
| mbedtls_base64_cond_assign_uchar(&result, &table[i], mbedtls_base64_eq(i, table_index)); |
| } |
| |
| return result; |
| } |
| |
| /* |
| * 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_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( ( C1 >> 2 ) & 0x3F ) ); |
| |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) ) & 0x3F ) ); |
| |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( ( ( ( C2 & 15 ) << 2 ) + ( C3 >> 6 ) ) & 0x3F ) ); |
| |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( C3 & 0x3F ) ); |
| } |
| |
| if( i < slen ) |
| { |
| C1 = *src++; |
| C2 = ( ( i + 1 ) < slen ) ? *src++ : 0; |
| |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( ( C1 >> 2 ) & 0x3F ) ); |
| |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( base64_enc_map ), |
| ( ( ( ( C1 & 3 ) << 4 ) + ( C2 >> 4 ) ) & 0x3F ) ); |
| |
| if( ( i + 1 ) < slen ) |
| *p++ = mbedtls_base64_table_lookup( base64_enc_map, sizeof( 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; |
| unsigned char dec_map_lookup; |
| |
| /* 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 ); |
| |
| dec_map_lookup = mbedtls_base64_table_lookup( base64_dec_map, sizeof( base64_dec_map ), src[i] ); |
| |
| if( src[i] > 127 || dec_map_lookup == 127 ) |
| return( MBEDTLS_ERR_BASE64_INVALID_CHARACTER ); |
| |
| if( dec_map_lookup < 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; |
| |
| dec_map_lookup = mbedtls_base64_table_lookup(base64_dec_map, sizeof( base64_dec_map ), *src ); |
| |
| mbedtls_base64_cond_assign_uint32( &j, j - 1, mbedtls_base64_eq( dec_map_lookup, 64 ) ); |
| x = ( x << 6 ) | ( dec_map_lookup & 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 */ |
