Revert "Remove Diffie-Hellman examples"
This reverts commit bea98b458136029c2585037c74c114ddc5af896e.
Conflicts:
* programs/Makefile:
* APPS: the layout of the definition has changed. re-add dh_client
and dh_server appropriately.
Run scripts/generate_visualc_files.pl to account for the added programs.
diff --git a/programs/pkey/CMakeLists.txt b/programs/pkey/CMakeLists.txt
index 944a100..5a37a42 100644
--- a/programs/pkey/CMakeLists.txt
+++ b/programs/pkey/CMakeLists.txt
@@ -1,6 +1,12 @@
+add_executable(dh_client dh_client.c)
+target_link_libraries(dh_client mbedtls)
+
add_executable(dh_genprime dh_genprime.c)
target_link_libraries(dh_genprime mbedtls)
+add_executable(dh_server dh_server.c)
+target_link_libraries(dh_server mbedtls)
+
add_executable(ecdh_curve25519 ecdh_curve25519.c)
target_link_libraries(ecdh_curve25519 mbedtls)
@@ -52,6 +58,6 @@
add_executable(pk_decrypt pk_decrypt.c)
target_link_libraries(pk_decrypt mbedtls)
-install(TARGETS dh_genprime key_app mpi_demo rsa_genkey rsa_sign rsa_verify rsa_encrypt rsa_decrypt pk_encrypt pk_decrypt pk_sign pk_verify gen_key
+install(TARGETS dh_client dh_genprime dh_server key_app mpi_demo rsa_genkey rsa_sign rsa_verify rsa_encrypt rsa_decrypt pk_encrypt pk_decrypt pk_sign pk_verify gen_key
DESTINATION "bin"
PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
diff --git a/programs/pkey/dh_client.c b/programs/pkey/dh_client.c
new file mode 100644
index 0000000..1dce31a
--- /dev/null
+++ b/programs/pkey/dh_client.c
@@ -0,0 +1,325 @@
+/*
+ * Diffie-Hellman-Merkle key exchange (client 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>
+#include <stdlib.h>
+#define mbedtls_printf printf
+#define mbedtls_time_t time_t
+#define mbedtls_exit exit
+#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#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_NAME "localhost"
+#define SERVER_PORT "11999"
+
+#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
+
+#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( void )
+{
+ FILE *f;
+
+ int ret = 1;
+ int exit_code = MBEDTLS_EXIT_FAILURE;
+ size_t n, buflen;
+ mbedtls_net_context server_fd;
+
+ unsigned char *p, *end;
+ unsigned char buf[2048];
+ unsigned char hash[32];
+ const char *pers = "dh_client";
+
+ 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( &server_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;
+ }
+
+ /*
+ * 2. Read the server's public RSA key
+ */
+ mbedtls_printf( "\n . Reading public key from rsa_pub.txt" );
+ fflush( stdout );
+
+ if( ( f = fopen( "rsa_pub.txt", "rb" ) ) == NULL )
+ {
+ mbedtls_printf( " failed\n ! Could not open rsa_pub.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 )
+ {
+ 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 );
+
+ /*
+ * 3. Initiate the connection
+ */
+ mbedtls_printf( "\n . Connecting to tcp/%s/%s", SERVER_NAME,
+ SERVER_PORT );
+ fflush( stdout );
+
+ if( ( ret = mbedtls_net_connect( &server_fd, SERVER_NAME,
+ SERVER_PORT, MBEDTLS_NET_PROTO_TCP ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_net_connect returned %d\n\n", ret );
+ goto exit;
+ }
+
+ /*
+ * 4a. First get the buffer length
+ */
+ mbedtls_printf( "\n . Receiving the server's DH parameters" );
+ fflush( stdout );
+
+ memset( buf, 0, sizeof( buf ) );
+
+ if( ( ret = mbedtls_net_recv( &server_fd, buf, 2 ) ) != 2 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
+ goto exit;
+ }
+
+ n = buflen = ( buf[0] << 8 ) | buf[1];
+ if( buflen < 1 || buflen > sizeof( buf ) )
+ {
+ mbedtls_printf( " failed\n ! Got an invalid buffer length\n\n" );
+ goto exit;
+ }
+
+ /*
+ * 4b. Get the DHM parameters: P, G and Ys = G^Xs mod P
+ */
+ memset( buf, 0, sizeof( buf ) );
+
+ if( ( ret = mbedtls_net_recv( &server_fd, buf, n ) ) != (int) n )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
+ goto exit;
+ }
+
+ p = buf, end = buf + buflen;
+
+ if( ( ret = mbedtls_dhm_read_params( &dhm, &p, end ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_dhm_read_params returned %d\n\n", ret );
+ goto exit;
+ }
+
+ if( dhm.len < 64 || dhm.len > 512 )
+ {
+ mbedtls_printf( " failed\n ! Invalid DHM modulus size\n\n" );
+ goto exit;
+ }
+
+ /*
+ * 5. Check that the server's RSA signature matches
+ * the SHA-256 hash of (P,G,Ys)
+ */
+ mbedtls_printf( "\n . Verifying the server's RSA signature" );
+ fflush( stdout );
+
+ p += 2;
+
+ if( ( n = (size_t) ( end - p ) ) != rsa.len )
+ {
+ mbedtls_printf( " failed\n ! Invalid RSA signature size\n\n" );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_sha1_ret( buf, (int)( p - 2 - buf ), hash ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_sha1_ret returned %d\n\n", ret );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, NULL, NULL, MBEDTLS_RSA_PUBLIC,
+ MBEDTLS_MD_SHA256, 0, hash, p ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_rsa_pkcs1_verify returned %d\n\n", ret );
+ goto exit;
+ }
+
+ /*
+ * 6. Send our public value: Yc = G ^ Xc mod P
+ */
+ mbedtls_printf( "\n . Sending own public value to server" );
+ fflush( stdout );
+
+ n = dhm.len;
+ if( ( ret = mbedtls_dhm_make_public( &dhm, (int) dhm.len, buf, n,
+ mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_dhm_make_public returned %d\n\n", ret );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_net_send( &server_fd, buf, n ) ) != (int) n )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_net_send 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 decryption 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,
+ * IVs and MACs.
+ */
+ mbedtls_printf( "...\n . Receiving and decrypting the ciphertext" );
+ fflush( stdout );
+
+ mbedtls_aes_setkey_dec( &aes, buf, 256 );
+
+ memset( buf, 0, sizeof( buf ) );
+
+ if( ( ret = mbedtls_net_recv( &server_fd, buf, 16 ) ) != 16 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_net_recv returned %d\n\n", ret );
+ goto exit;
+ }
+
+ mbedtls_aes_crypt_ecb( &aes, MBEDTLS_AES_DECRYPT, buf, buf );
+ buf[16] = '\0';
+ mbedtls_printf( "\n . Plaintext is \"%s\"\n\n", (char *) buf );
+
+ exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+
+ mbedtls_net_free( &server_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( exit_code );
+}
+#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 */
diff --git a/programs/pkey/dh_server.c b/programs/pkey/dh_server.c
new file mode 100644
index 0000000..a797e60
--- /dev/null
+++ b/programs/pkey/dh_server.c
@@ -0,0 +1,348 @@
+/*
+ * 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>
+#include <stdlib.h>
+#define mbedtls_printf printf
+#define mbedtls_time_t time_t
+#define mbedtls_exit exit
+#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#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
+
+#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( void )
+{
+ FILE *f;
+
+ int ret = 1;
+ int exit_code = MBEDTLS_EXIT_FAILURE;
+ 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_mpi N, P, Q, D, E;
+
+ 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 );
+
+ mbedtls_mpi_init( &N ); mbedtls_mpi_init( &P ); mbedtls_mpi_init( &Q );
+ mbedtls_mpi_init( &D ); mbedtls_mpi_init( &E );
+
+ /*
+ * 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 )
+ {
+ 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( &N , 16, f ) ) != 0 ||
+ ( ret = mbedtls_mpi_read_file( &E , 16, f ) ) != 0 ||
+ ( ret = mbedtls_mpi_read_file( &D , 16, f ) ) != 0 ||
+ ( ret = mbedtls_mpi_read_file( &P , 16, f ) ) != 0 ||
+ ( ret = mbedtls_mpi_read_file( &Q , 16, f ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n",
+ ret );
+ fclose( f );
+ goto exit;
+ }
+ fclose( f );
+
+ if( ( ret = mbedtls_rsa_import( &rsa, &N, &P, &Q, &D, &E ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_rsa_import returned %d\n\n",
+ ret );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_rsa_complete( &rsa ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_rsa_complete returned %d\n\n",
+ ret );
+ goto exit;
+ }
+
+ /*
+ * 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 )
+ {
+ 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
+ */
+ if( ( ret = mbedtls_sha1_ret( buf, n, hash ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_sha1_ret returned %d\n\n", ret );
+ goto exit;
+ }
+
+ 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 ) );
+
+ n = dhm.len;
+ 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_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+
+ mbedtls_mpi_free( &N ); mbedtls_mpi_free( &P ); mbedtls_mpi_free( &Q );
+ mbedtls_mpi_free( &D ); mbedtls_mpi_free( &E );
+
+ 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( exit_code );
+}
+#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 */