mbedtls/programs/pkey/pk_decrypt.c
2013-09-29 15:01:42 +02:00

155 lines
4 KiB
C

/*
* Public key-based simple decryption program
*
* Copyright (C) 2006-2013, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* 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.
*/
#include "polarssl/config.h"
#include <string.h>
#include <stdio.h>
#include "polarssl/error.h"
#include "polarssl/pk.h"
#include "polarssl/entropy.h"
#include "polarssl/ctr_drbg.h"
#if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_PK_PARSE_C) || \
!defined(POLARSSL_FS_IO) || !defined(POLARSSL_ENTROPY_C) || \
!defined(POLARSSL_CTR_DRBG_C)
int main( int argc, char *argv[] )
{
((void) argc);
((void) argv);
printf("POLARSSL_BIGNUM_C and/or POLARSSL_PK_PARSE_C and/or "
"POLARSSL_FS_IO and/or POLARSSL_ENTROPY_C and/or "
"POLARSSL_CTR_DRBG_C not defined.\n");
return( 0 );
}
#else
int main( int argc, char *argv[] )
{
FILE *f;
int ret, c;
size_t i, olen = 0;
pk_context pk;
entropy_context entropy;
ctr_drbg_context ctr_drbg;
unsigned char result[1024];
unsigned char buf[512];
const char *pers = "pk_decrypt";
((void) argv);
memset(result, 0, sizeof( result ) );
ret = 1;
if( argc != 2 )
{
printf( "usage: pk_decrypt <key_file>\n" );
#if defined(_WIN32)
printf( "\n" );
#endif
goto exit;
}
printf( "\n . Seeding the random number generator..." );
fflush( stdout );
entropy_init( &entropy );
if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
printf( " failed\n ! ctr_drbg_init returned %d\n", ret );
goto exit;
}
printf( "\n . Reading private key from '%s'", argv[1] );
fflush( stdout );
pk_init( &pk );
if( ( ret = pk_parse_keyfile( &pk, argv[1], "" ) ) != 0 )
{
printf( " failed\n ! pk_parse_keyfile returned -0x%04x\n", -ret );
goto exit;
}
/*
* Extract the RSA encrypted value from the text file
*/
ret = 1;
if( ( f = fopen( "result-enc.txt", "rb" ) ) == NULL )
{
printf( "\n ! Could not open %s\n\n", "result-enc.txt" );
goto exit;
}
i = 0;
while( fscanf( f, "%02X", &c ) > 0 &&
i < (int) sizeof( buf ) )
buf[i++] = (unsigned char) c;
fclose( f );
/*
* Decrypt the encrypted RSA data and print the result.
*/
printf( "\n . Decrypting the encrypted data" );
fflush( stdout );
if( ( ret = pk_decrypt( &pk, buf, i, result, &olen, sizeof(result),
ctr_drbg_random, &ctr_drbg ) ) != 0 )
{
printf( " failed\n ! pk_decrypt returned -0x%04x\n", -ret );
goto exit;
}
printf( "\n . OK\n\n" );
printf( "The decrypted result is: '%s'\n\n", result );
ret = 0;
exit:
entropy_free( &entropy );
#if defined(POLARSSL_ERROR_C)
polarssl_strerror( ret, (char *) buf, sizeof(buf) );
printf( " ! Last error was: %s\n", buf );
#endif
#if defined(_WIN32)
printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
return( ret );
}
#endif /* POLARSSL_BIGNUM_C && POLARSSL_PK_PARSE_C && POLARSSL_FS_IO &&
POLARSSL_ENTROPY_C && POLARSSL_CTR_DRBG_C */