mbedtls/programs/pkey/ecdh_curve25519.c
Thomas Daubney 64042b8d3d Fix typo
Fix typo that was caught during review.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
2022-05-18 09:59:55 +01:00

222 lines
6.3 KiB
C

/*
* Example ECDHE with Curve25519 program
*
* 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 "mbedtls/build_info.h"
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#include <stdlib.h>
#define mbedtls_printf printf
#define mbedtls_exit exit
#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
#endif /* MBEDTLS_PLATFORM_C */
#if !defined(MBEDTLS_ECDH_C) || \
!defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) || \
!defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C)
int main( void )
{
mbedtls_printf( "MBEDTLS_ECDH_C and/or "
"MBEDTLS_ECP_DP_CURVE25519_ENABLED and/or "
"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
"not defined\n" );
mbedtls_exit( 0 );
}
#else
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/ecdh.h"
#include <string.h>
int main( int argc, char *argv[] )
{
int ret = 1;
int exit_code = MBEDTLS_EXIT_FAILURE;
mbedtls_ecdh_context ctx_cli, ctx_srv;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
unsigned char cli_to_srv[36], srv_to_cli[33];
const char pers[] = "ecdh";
size_t olen;
unsigned char secret_cli[32], secret_srv[32];
const unsigned char *p_cli_to_srv = cli_to_srv;
((void) argc);
((void) argv);
mbedtls_ecdh_init( &ctx_cli );
mbedtls_ecdh_init( &ctx_srv );
mbedtls_ctr_drbg_init( &ctr_drbg );
/*
* Initialize random number generation
*/
mbedtls_printf( " . Seed 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,
sizeof pers ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Client: initialize context and generate keypair
*/
mbedtls_printf( " . Set up client context, generate EC key pair..." );
fflush( stdout );
ret = mbedtls_ecdh_setup( &ctx_cli, MBEDTLS_ECP_DP_CURVE25519 );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_setup returned %d\n", ret );
goto exit;
}
ret = mbedtls_ecdh_make_params( &ctx_cli, &olen, cli_to_srv,
sizeof( cli_to_srv ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_make_params returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Server: initialize context and generate keypair
*/
mbedtls_printf( " . Server: read params, generate public key..." );
fflush( stdout );
ret = mbedtls_ecdh_read_params( &ctx_srv, &p_cli_to_srv,
p_cli_to_srv + sizeof( cli_to_srv ) );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_read_params returned %d\n",
ret );
goto exit;
}
ret = mbedtls_ecdh_make_public( &ctx_srv, &olen, srv_to_cli,
sizeof( srv_to_cli ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_make_public returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Client: read public key
*/
mbedtls_printf( " . Client: read public key..." );
fflush( stdout );
ret = mbedtls_ecdh_read_public( &ctx_cli, srv_to_cli,
sizeof( srv_to_cli ) );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_read_public returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Calculate secrets
*/
mbedtls_printf( " . Calculate secrets..." );
fflush( stdout );
ret = mbedtls_ecdh_calc_secret( &ctx_cli, &olen, secret_cli,
sizeof( secret_cli ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_calc_secret returned %d\n",
ret );
goto exit;
}
ret = mbedtls_ecdh_calc_secret( &ctx_srv, &olen, secret_srv,
sizeof( secret_srv ),
mbedtls_ctr_drbg_random, &ctr_drbg );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ecdh_calc_secret returned %d\n",
ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* Verification: are the computed secrets equal?
*/
mbedtls_printf( " . Check if both calculated secrets are equal..." );
fflush( stdout );
ret = memcmp( secret_srv, secret_cli, sizeof( secret_srv ) );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! Shared secrets not equal.\n" );
goto exit;
}
mbedtls_printf( " ok\n" );
exit_code = MBEDTLS_EXIT_SUCCESS;
exit:
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
mbedtls_ecdh_free( &ctx_srv );
mbedtls_ecdh_free( &ctx_cli );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
mbedtls_exit( exit_code );
}
#endif /* MBEDTLS_ECDH_C && MBEDTLS_ECP_DP_CURVE25519_ENABLED &&
MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C */