| /* |
| * AES-256 file encryption program |
| * |
| * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved |
| * 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. |
| * |
| * This file is part of mbed TLS (https://tls.mbed.org) |
| */ |
| |
| /* Enable definition of fileno() even when compiling with -std=c99. Must be |
| * set before config.h, which pulls in glibc's features.h indirectly. |
| * Harmless on other platforms. */ |
| #define _POSIX_C_SOURCE 1 |
| |
| #if !defined(MBEDTLS_CONFIG_FILE) |
| #include "mbedtls/config.h" |
| #else |
| #include MBEDTLS_CONFIG_FILE |
| #endif |
| |
| #if defined(MBEDTLS_PLATFORM_C) |
| #include "mbedtls/platform.h" |
| #else |
| #include <stdio.h> |
| #include <stdlib.h> |
| #define mbedtls_fprintf fprintf |
| #define mbedtls_printf printf |
| #define mbedtls_exit exit |
| #define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS |
| #define MBEDTLS_EXIT_FAILURE EXIT_FAILURE |
| #endif /* MBEDTLS_PLATFORM_C */ |
| |
| #include "mbedtls/aes.h" |
| #include "mbedtls/md.h" |
| #include "mbedtls/platform_util.h" |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #if defined(_WIN32) |
| #include <windows.h> |
| #if !defined(_WIN32_WCE) |
| #include <io.h> |
| #endif |
| #else |
| #include <sys/types.h> |
| #include <unistd.h> |
| #endif |
| |
| #define MODE_ENCRYPT 0 |
| #define MODE_DECRYPT 1 |
| |
| #define USAGE \ |
| "\n aescrypt2 <mode> <input filename> <output filename> <key>\n" \ |
| "\n <mode>: 0 = encrypt, 1 = decrypt\n" \ |
| "\n example: aescrypt2 0 file file.aes hex:E76B2413958B00E193\n" \ |
| "\n" |
| |
| #if !defined(MBEDTLS_AES_C) || !defined(MBEDTLS_SHA256_C) || \ |
| !defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_MD_C) |
| int main( void ) |
| { |
| mbedtls_printf("MBEDTLS_AES_C and/or MBEDTLS_SHA256_C " |
| "and/or MBEDTLS_FS_IO and/or MBEDTLS_MD_C " |
| "not defined.\n"); |
| return( 0 ); |
| } |
| #else |
| |
| #if defined(MBEDTLS_CHECK_PARAMS) |
| #include "mbedtls/platform_util.h" |
| void mbedtls_param_failed( const char *failure_condition, |
| const char *file, |
| int line ) |
| { |
| mbedtls_printf( "%s:%i: Input param failed - %s\n", |
| file, line, failure_condition ); |
| mbedtls_exit( MBEDTLS_EXIT_FAILURE ); |
| } |
| #endif |
| |
| int main( int argc, char *argv[] ) |
| { |
| int ret = 0; |
| int exit_code = MBEDTLS_EXIT_FAILURE; |
| |
| unsigned int i, n; |
| int mode, lastn; |
| size_t keylen; |
| FILE *fkey, *fin = NULL, *fout = NULL; |
| |
| char *p; |
| |
| unsigned char IV[16]; |
| unsigned char tmp[16]; |
| unsigned char key[512]; |
| unsigned char digest[32]; |
| unsigned char buffer[1024]; |
| unsigned char diff; |
| |
| mbedtls_aes_context aes_ctx; |
| mbedtls_md_context_t sha_ctx; |
| |
| #if defined(_WIN32_WCE) |
| long filesize, offset; |
| #elif defined(_WIN32) |
| LARGE_INTEGER li_size; |
| __int64 filesize, offset; |
| #else |
| off_t filesize, offset; |
| #endif |
| |
| mbedtls_aes_init( &aes_ctx ); |
| mbedtls_md_init( &sha_ctx ); |
| |
| ret = mbedtls_md_setup( &sha_ctx, mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ), 1 ); |
| if( ret != 0 ) |
| { |
| mbedtls_printf( " ! mbedtls_md_setup() returned -0x%04x\n", -ret ); |
| goto exit; |
| } |
| |
| /* |
| * Parse the command-line arguments. |
| */ |
| if( argc != 5 ) |
| { |
| mbedtls_printf( USAGE ); |
| |
| #if defined(_WIN32) |
| mbedtls_printf( "\n Press Enter to exit this program.\n" ); |
| fflush( stdout ); getchar(); |
| #endif |
| |
| goto exit; |
| } |
| |
| mode = atoi( argv[1] ); |
| memset( IV, 0, sizeof( IV ) ); |
| memset( key, 0, sizeof( key ) ); |
| memset( digest, 0, sizeof( digest ) ); |
| memset( buffer, 0, sizeof( buffer ) ); |
| |
| if( mode != MODE_ENCRYPT && mode != MODE_DECRYPT ) |
| { |
| mbedtls_fprintf( stderr, "invalide operation mode\n" ); |
| goto exit; |
| } |
| |
| if( strcmp( argv[2], argv[3] ) == 0 ) |
| { |
| mbedtls_fprintf( stderr, "input and output filenames must differ\n" ); |
| goto exit; |
| } |
| |
| if( ( fin = fopen( argv[2], "rb" ) ) == NULL ) |
| { |
| mbedtls_fprintf( stderr, "fopen(%s,rb) failed\n", argv[2] ); |
| goto exit; |
| } |
| |
| if( ( fout = fopen( argv[3], "wb+" ) ) == NULL ) |
| { |
| mbedtls_fprintf( stderr, "fopen(%s,wb+) failed\n", argv[3] ); |
| goto exit; |
| } |
| |
| /* |
| * Read the secret key from file or command line |
| */ |
| if( ( fkey = fopen( argv[4], "rb" ) ) != NULL ) |
| { |
| keylen = fread( key, 1, sizeof( key ), fkey ); |
| fclose( fkey ); |
| } |
| else |
| { |
| if( memcmp( argv[4], "hex:", 4 ) == 0 ) |
| { |
| p = &argv[4][4]; |
| keylen = 0; |
| |
| while( sscanf( p, "%02X", &n ) > 0 && |
| keylen < (int) sizeof( key ) ) |
| { |
| key[keylen++] = (unsigned char) n; |
| p += 2; |
| } |
| } |
| else |
| { |
| keylen = strlen( argv[4] ); |
| |
| if( keylen > (int) sizeof( key ) ) |
| keylen = (int) sizeof( key ); |
| |
| memcpy( key, argv[4], keylen ); |
| } |
| } |
| |
| #if defined(_WIN32_WCE) |
| filesize = fseek( fin, 0L, SEEK_END ); |
| #else |
| #if defined(_WIN32) |
| /* |
| * Support large files (> 2Gb) on Win32 |
| */ |
| li_size.QuadPart = 0; |
| li_size.LowPart = |
| SetFilePointer( (HANDLE) _get_osfhandle( _fileno( fin ) ), |
| li_size.LowPart, &li_size.HighPart, FILE_END ); |
| |
| if( li_size.LowPart == 0xFFFFFFFF && GetLastError() != NO_ERROR ) |
| { |
| mbedtls_fprintf( stderr, "SetFilePointer(0,FILE_END) failed\n" ); |
| goto exit; |
| } |
| |
| filesize = li_size.QuadPart; |
| #else |
| if( ( filesize = lseek( fileno( fin ), 0, SEEK_END ) ) < 0 ) |
| { |
| perror( "lseek" ); |
| goto exit; |
| } |
| #endif |
| #endif |
| |
| if( fseek( fin, 0, SEEK_SET ) < 0 ) |
| { |
| mbedtls_fprintf( stderr, "fseek(0,SEEK_SET) failed\n" ); |
| goto exit; |
| } |
| |
| if( mode == MODE_ENCRYPT ) |
| { |
| /* |
| * Generate the initialization vector as: |
| * IV = SHA-256( filesize || filename )[0..15] |
| */ |
| for( i = 0; i < 8; i++ ) |
| buffer[i] = (unsigned char)( filesize >> ( i << 3 ) ); |
| |
| p = argv[2]; |
| |
| mbedtls_md_starts( &sha_ctx ); |
| mbedtls_md_update( &sha_ctx, buffer, 8 ); |
| mbedtls_md_update( &sha_ctx, (unsigned char *) p, strlen( p ) ); |
| mbedtls_md_finish( &sha_ctx, digest ); |
| |
| memcpy( IV, digest, 16 ); |
| |
| /* |
| * The last four bits in the IV are actually used |
| * to store the file size modulo the AES block size. |
| */ |
| lastn = (int)( filesize & 0x0F ); |
| |
| IV[15] = (unsigned char) |
| ( ( IV[15] & 0xF0 ) | lastn ); |
| |
| /* |
| * Append the IV at the beginning of the output. |
| */ |
| if( fwrite( IV, 1, 16, fout ) != 16 ) |
| { |
| mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", 16 ); |
| goto exit; |
| } |
| |
| /* |
| * Hash the IV and the secret key together 8192 times |
| * using the result to setup the AES context and HMAC. |
| */ |
| memset( digest, 0, 32 ); |
| memcpy( digest, IV, 16 ); |
| |
| for( i = 0; i < 8192; i++ ) |
| { |
| mbedtls_md_starts( &sha_ctx ); |
| mbedtls_md_update( &sha_ctx, digest, 32 ); |
| mbedtls_md_update( &sha_ctx, key, keylen ); |
| mbedtls_md_finish( &sha_ctx, digest ); |
| } |
| |
| mbedtls_aes_setkey_enc( &aes_ctx, digest, 256 ); |
| mbedtls_md_hmac_starts( &sha_ctx, digest, 32 ); |
| |
| /* |
| * Encrypt and write the ciphertext. |
| */ |
| for( offset = 0; offset < filesize; offset += 16 ) |
| { |
| n = ( filesize - offset > 16 ) ? 16 : (int) |
| ( filesize - offset ); |
| |
| if( fread( buffer, 1, n, fin ) != (size_t) n ) |
| { |
| mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", n ); |
| goto exit; |
| } |
| |
| for( i = 0; i < 16; i++ ) |
| buffer[i] = (unsigned char)( buffer[i] ^ IV[i] ); |
| |
| mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_ENCRYPT, buffer, buffer ); |
| mbedtls_md_hmac_update( &sha_ctx, buffer, 16 ); |
| |
| if( fwrite( buffer, 1, 16, fout ) != 16 ) |
| { |
| mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", 16 ); |
| goto exit; |
| } |
| |
| memcpy( IV, buffer, 16 ); |
| } |
| |
| /* |
| * Finally write the HMAC. |
| */ |
| mbedtls_md_hmac_finish( &sha_ctx, digest ); |
| |
| if( fwrite( digest, 1, 32, fout ) != 32 ) |
| { |
| mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", 16 ); |
| goto exit; |
| } |
| } |
| |
| if( mode == MODE_DECRYPT ) |
| { |
| /* |
| * The encrypted file must be structured as follows: |
| * |
| * 00 .. 15 Initialization Vector |
| * 16 .. 31 AES Encrypted Block #1 |
| * .. |
| * N*16 .. (N+1)*16 - 1 AES Encrypted Block #N |
| * (N+1)*16 .. (N+1)*16 + 32 HMAC-SHA-256(ciphertext) |
| */ |
| if( filesize < 48 ) |
| { |
| mbedtls_fprintf( stderr, "File too short to be encrypted.\n" ); |
| goto exit; |
| } |
| |
| if( ( filesize & 0x0F ) != 0 ) |
| { |
| mbedtls_fprintf( stderr, "File size not a multiple of 16.\n" ); |
| goto exit; |
| } |
| |
| /* |
| * Subtract the IV + HMAC length. |
| */ |
| filesize -= ( 16 + 32 ); |
| |
| /* |
| * Read the IV and original filesize modulo 16. |
| */ |
| if( fread( buffer, 1, 16, fin ) != 16 ) |
| { |
| mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", 16 ); |
| goto exit; |
| } |
| |
| memcpy( IV, buffer, 16 ); |
| lastn = IV[15] & 0x0F; |
| |
| /* |
| * Hash the IV and the secret key together 8192 times |
| * using the result to setup the AES context and HMAC. |
| */ |
| memset( digest, 0, 32 ); |
| memcpy( digest, IV, 16 ); |
| |
| for( i = 0; i < 8192; i++ ) |
| { |
| mbedtls_md_starts( &sha_ctx ); |
| mbedtls_md_update( &sha_ctx, digest, 32 ); |
| mbedtls_md_update( &sha_ctx, key, keylen ); |
| mbedtls_md_finish( &sha_ctx, digest ); |
| } |
| |
| mbedtls_aes_setkey_dec( &aes_ctx, digest, 256 ); |
| mbedtls_md_hmac_starts( &sha_ctx, digest, 32 ); |
| |
| /* |
| * Decrypt and write the plaintext. |
| */ |
| for( offset = 0; offset < filesize; offset += 16 ) |
| { |
| if( fread( buffer, 1, 16, fin ) != 16 ) |
| { |
| mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", 16 ); |
| goto exit; |
| } |
| |
| memcpy( tmp, buffer, 16 ); |
| |
| mbedtls_md_hmac_update( &sha_ctx, buffer, 16 ); |
| mbedtls_aes_crypt_ecb( &aes_ctx, MBEDTLS_AES_DECRYPT, buffer, buffer ); |
| |
| for( i = 0; i < 16; i++ ) |
| buffer[i] = (unsigned char)( buffer[i] ^ IV[i] ); |
| |
| memcpy( IV, tmp, 16 ); |
| |
| n = ( lastn > 0 && offset == filesize - 16 ) |
| ? lastn : 16; |
| |
| if( fwrite( buffer, 1, n, fout ) != (size_t) n ) |
| { |
| mbedtls_fprintf( stderr, "fwrite(%d bytes) failed\n", n ); |
| goto exit; |
| } |
| } |
| |
| /* |
| * Verify the message authentication code. |
| */ |
| mbedtls_md_hmac_finish( &sha_ctx, digest ); |
| |
| if( fread( buffer, 1, 32, fin ) != 32 ) |
| { |
| mbedtls_fprintf( stderr, "fread(%d bytes) failed\n", 32 ); |
| goto exit; |
| } |
| |
| /* Use constant-time buffer comparison */ |
| diff = 0; |
| for( i = 0; i < 32; i++ ) |
| diff |= digest[i] ^ buffer[i]; |
| |
| if( diff != 0 ) |
| { |
| mbedtls_fprintf( stderr, "HMAC check failed: wrong key, " |
| "or file corrupted.\n" ); |
| goto exit; |
| } |
| } |
| |
| exit_code = MBEDTLS_EXIT_SUCCESS; |
| |
| exit: |
| if( fin ) |
| fclose( fin ); |
| if( fout ) |
| fclose( fout ); |
| |
| /* Zeroize all command line arguments to also cover |
| the case when the user has missed or reordered some, |
| in which case the key might not be in argv[4]. */ |
| for( i = 0; i < (unsigned int) argc; i++ ) |
| mbedtls_platform_zeroize( argv[i], strlen( argv[i] ) ); |
| |
| mbedtls_platform_zeroize( IV, sizeof( IV ) ); |
| mbedtls_platform_zeroize( key, sizeof( key ) ); |
| mbedtls_platform_zeroize( tmp, sizeof( tmp ) ); |
| mbedtls_platform_zeroize( buffer, sizeof( buffer ) ); |
| mbedtls_platform_zeroize( digest, sizeof( digest ) ); |
| |
| mbedtls_aes_free( &aes_ctx ); |
| mbedtls_md_free( &sha_ctx ); |
| |
| return( exit_code ); |
| } |
| #endif /* MBEDTLS_AES_C && MBEDTLS_SHA256_C && MBEDTLS_FS_IO */ |