309 lines
9.2 KiB
C
309 lines
9.2 KiB
C
/*
|
|
* Diffie-Hellman-Merkle key exchange (server side)
|
|
*
|
|
* 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)
|
|
*/
|
|
|
|
#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>
|
|
#define mbedtls_printf printf
|
|
#define mbedtls_time_t time_t
|
|
#endif
|
|
|
|
#if defined(MBEDTLS_AES_C) && defined(MBEDTLS_DHM_C) && \
|
|
defined(MBEDTLS_ENTROPY_C) && defined(MBEDTLS_NET_C) && \
|
|
defined(MBEDTLS_RSA_C) && defined(MBEDTLS_SHA256_C) && \
|
|
defined(MBEDTLS_FS_IO) && defined(MBEDTLS_CTR_DRBG_C) && \
|
|
defined(MBEDTLS_SHA1_C)
|
|
#include "mbedtls/net_sockets.h"
|
|
#include "mbedtls/aes.h"
|
|
#include "mbedtls/dhm.h"
|
|
#include "mbedtls/rsa.h"
|
|
#include "mbedtls/sha1.h"
|
|
#include "mbedtls/entropy.h"
|
|
#include "mbedtls/ctr_drbg.h"
|
|
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#endif
|
|
|
|
#define SERVER_PORT "11999"
|
|
#define PLAINTEXT "==Hello there!=="
|
|
|
|
#if !defined(MBEDTLS_AES_C) || !defined(MBEDTLS_DHM_C) || \
|
|
!defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_NET_C) || \
|
|
!defined(MBEDTLS_RSA_C) || !defined(MBEDTLS_SHA256_C) || \
|
|
!defined(MBEDTLS_FS_IO) || !defined(MBEDTLS_CTR_DRBG_C) || \
|
|
!defined(MBEDTLS_SHA1_C)
|
|
int main( void )
|
|
{
|
|
mbedtls_printf("MBEDTLS_AES_C and/or MBEDTLS_DHM_C and/or MBEDTLS_ENTROPY_C "
|
|
"and/or MBEDTLS_NET_C and/or MBEDTLS_RSA_C and/or "
|
|
"MBEDTLS_SHA256_C and/or MBEDTLS_FS_IO and/or "
|
|
"MBEDTLS_CTR_DRBG_C not defined.\n");
|
|
return( 0 );
|
|
}
|
|
#else
|
|
int main( void )
|
|
{
|
|
FILE *f;
|
|
|
|
int ret;
|
|
size_t n, buflen;
|
|
mbedtls_net_context listen_fd, client_fd;
|
|
|
|
unsigned char buf[2048];
|
|
unsigned char hash[32];
|
|
unsigned char buf2[2];
|
|
const char *pers = "dh_server";
|
|
|
|
mbedtls_entropy_context entropy;
|
|
mbedtls_ctr_drbg_context ctr_drbg;
|
|
mbedtls_rsa_context rsa;
|
|
mbedtls_dhm_context dhm;
|
|
mbedtls_aes_context aes;
|
|
|
|
mbedtls_net_init( &listen_fd );
|
|
mbedtls_net_init( &client_fd );
|
|
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, MBEDTLS_MD_SHA256 );
|
|
mbedtls_dhm_init( &dhm );
|
|
mbedtls_aes_init( &aes );
|
|
mbedtls_ctr_drbg_init( &ctr_drbg );
|
|
|
|
/*
|
|
* 1. Setup the RNG
|
|
*/
|
|
mbedtls_printf( "\n . Seeding the random number generator" );
|
|
fflush( stdout );
|
|
|
|
mbedtls_entropy_init( &entropy );
|
|
if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
|
|
(const unsigned char *) pers,
|
|
strlen( pers ) ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* 2a. Read the server's private RSA key
|
|
*/
|
|
mbedtls_printf( "\n . Reading private key from rsa_priv.txt" );
|
|
fflush( stdout );
|
|
|
|
if( ( f = fopen( "rsa_priv.txt", "rb" ) ) == NULL )
|
|
{
|
|
ret = 1;
|
|
mbedtls_printf( " failed\n ! Could not open rsa_priv.txt\n" \
|
|
" ! Please run rsa_genkey first\n\n" );
|
|
goto exit;
|
|
}
|
|
|
|
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, 0 );
|
|
|
|
if( ( ret = mbedtls_mpi_read_file( &rsa.N , 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.E , 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.D , 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.P , 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.Q , 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.DP, 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.DQ, 16, f ) ) != 0 ||
|
|
( ret = mbedtls_mpi_read_file( &rsa.QP, 16, f ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
|
|
fclose( f );
|
|
goto exit;
|
|
}
|
|
|
|
rsa.len = ( mbedtls_mpi_bitlen( &rsa.N ) + 7 ) >> 3;
|
|
|
|
fclose( f );
|
|
|
|
/*
|
|
* 2b. Get the DHM modulus and generator
|
|
*/
|
|
mbedtls_printf( "\n . Reading DH parameters from dh_prime.txt" );
|
|
fflush( stdout );
|
|
|
|
if( ( f = fopen( "dh_prime.txt", "rb" ) ) == NULL )
|
|
{
|
|
ret = 1;
|
|
mbedtls_printf( " failed\n ! Could not open dh_prime.txt\n" \
|
|
" ! Please run dh_genprime first\n\n" );
|
|
goto exit;
|
|
}
|
|
|
|
if( mbedtls_mpi_read_file( &dhm.P, 16, f ) != 0 ||
|
|
mbedtls_mpi_read_file( &dhm.G, 16, f ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! Invalid DH parameter file\n\n" );
|
|
fclose( f );
|
|
goto exit;
|
|
}
|
|
|
|
fclose( f );
|
|
|
|
/*
|
|
* 3. Wait for a client to connect
|
|
*/
|
|
mbedtls_printf( "\n . Waiting for a remote connection" );
|
|
fflush( stdout );
|
|
|
|
if( ( ret = mbedtls_net_bind( &listen_fd, NULL, SERVER_PORT, MBEDTLS_NET_PROTO_TCP ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_net_bind returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
|
|
NULL, 0, NULL ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_net_accept returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* 4. Setup the DH parameters (P,G,Ys)
|
|
*/
|
|
mbedtls_printf( "\n . Sending the server's DH parameters" );
|
|
fflush( stdout );
|
|
|
|
memset( buf, 0, sizeof( buf ) );
|
|
|
|
if( ( ret = mbedtls_dhm_make_params( &dhm, (int) mbedtls_mpi_size( &dhm.P ), buf, &n,
|
|
mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_dhm_make_params returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* 5. Sign the parameters and send them
|
|
*/
|
|
mbedtls_sha1( buf, n, hash );
|
|
|
|
buf[n ] = (unsigned char)( rsa.len >> 8 );
|
|
buf[n + 1] = (unsigned char)( rsa.len );
|
|
|
|
if( ( ret = mbedtls_rsa_pkcs1_sign( &rsa, NULL, NULL, MBEDTLS_RSA_PRIVATE, MBEDTLS_MD_SHA256,
|
|
0, hash, buf + n + 2 ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_sign returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
buflen = n + 2 + rsa.len;
|
|
buf2[0] = (unsigned char)( buflen >> 8 );
|
|
buf2[1] = (unsigned char)( buflen );
|
|
|
|
if( ( ret = mbedtls_net_send( &client_fd, buf2, 2 ) ) != 2 ||
|
|
( ret = mbedtls_net_send( &client_fd, buf, buflen ) ) != (int) buflen )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_net_send returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* 6. Get the client's public value: Yc = G ^ Xc mod P
|
|
*/
|
|
mbedtls_printf( "\n . Receiving the client's public value" );
|
|
fflush( stdout );
|
|
|
|
memset( buf, 0, sizeof( buf ) );
|
|
|
|
if( ( ret = mbedtls_net_recv( &client_fd, buf, n ) ) != (int) n )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
if( ( ret = mbedtls_dhm_read_public( &dhm, buf, dhm.len ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_dhm_read_public returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
/*
|
|
* 7. Derive the shared secret: K = Ys ^ Xc mod P
|
|
*/
|
|
mbedtls_printf( "\n . Shared secret: " );
|
|
fflush( stdout );
|
|
|
|
if( ( ret = mbedtls_dhm_calc_secret( &dhm, buf, sizeof( buf ), &n,
|
|
mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_dhm_calc_secret returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
for( n = 0; n < 16; n++ )
|
|
mbedtls_printf( "%02x", buf[n] );
|
|
|
|
/*
|
|
* 8. Setup the AES-256 encryption key
|
|
*
|
|
* This is an overly simplified example; best practice is
|
|
* to hash the shared secret with a random value to derive
|
|
* the keying material for the encryption/decryption keys
|
|
* and MACs.
|
|
*/
|
|
mbedtls_printf( "...\n . Encrypting and sending the ciphertext" );
|
|
fflush( stdout );
|
|
|
|
mbedtls_aes_setkey_enc( &aes, buf, 256 );
|
|
memcpy( buf, PLAINTEXT, 16 );
|
|
mbedtls_aes_crypt_ecb( &aes, MBEDTLS_AES_ENCRYPT, buf, buf );
|
|
|
|
if( ( ret = mbedtls_net_send( &client_fd, buf, 16 ) ) != 16 )
|
|
{
|
|
mbedtls_printf( " failed\n ! mbedtls_net_send returned %d\n\n", ret );
|
|
goto exit;
|
|
}
|
|
|
|
mbedtls_printf( "\n\n" );
|
|
|
|
exit:
|
|
|
|
mbedtls_net_free( &client_fd );
|
|
mbedtls_net_free( &listen_fd );
|
|
|
|
mbedtls_aes_free( &aes );
|
|
mbedtls_rsa_free( &rsa );
|
|
mbedtls_dhm_free( &dhm );
|
|
mbedtls_ctr_drbg_free( &ctr_drbg );
|
|
mbedtls_entropy_free( &entropy );
|
|
|
|
#if defined(_WIN32)
|
|
mbedtls_printf( " + Press Enter to exit this program.\n" );
|
|
fflush( stdout ); getchar();
|
|
#endif
|
|
|
|
return( ret );
|
|
}
|
|
#endif /* MBEDTLS_AES_C && MBEDTLS_DHM_C && MBEDTLS_ENTROPY_C &&
|
|
MBEDTLS_NET_C && MBEDTLS_RSA_C && MBEDTLS_SHA256_C &&
|
|
MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */
|