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-rw-r--r--programs/pkey/dh_client.c297
1 files changed, 297 insertions, 0 deletions
diff --git a/programs/pkey/dh_client.c b/programs/pkey/dh_client.c
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--- /dev/null
+++ b/programs/pkey/dh_client.c
@@ -0,0 +1,297 @@
+/*
+ * Diffie-Hellman-Merkle key exchange (client side)
+ *
+ * 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"
+
+#include "mbedtls/platform.h"
+
+#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");
+ mbedtls_exit( 0 );
+}
+#else
+
+
+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_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 );
+
+ if( ( ret = mbedtls_mpi_read_file( &rsa.MBEDTLS_PRIVATE(N), 16, f ) ) != 0 ||
+ ( ret = mbedtls_mpi_read_file( &rsa.MBEDTLS_PRIVATE(E), 16, f ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_mpi_read_file returned %d\n\n", ret );
+ fclose( f );
+ goto exit;
+ }
+
+ rsa.MBEDTLS_PRIVATE(len) = ( mbedtls_mpi_bitlen( &rsa.MBEDTLS_PRIVATE(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;
+ }
+
+ n = mbedtls_dhm_get_len( &dhm );
+ if( n < 64 || n > 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.MBEDTLS_PRIVATE(len) )
+ {
+ mbedtls_printf( " failed\n ! Invalid RSA signature size\n\n" );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_sha1( buf, (int)( p - 2 - buf ), hash ) ) != 0 )
+ {
+ mbedtls_printf( " failed\n ! mbedtls_sha1 returned %d\n\n", ret );
+ goto exit;
+ }
+
+ if( ( ret = mbedtls_rsa_pkcs1_verify( &rsa, MBEDTLS_MD_SHA256,
+ 32, 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 = mbedtls_dhm_get_len( &dhm );
+ if( ( ret = mbedtls_dhm_make_public( &dhm, (int) n, 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 );
+
+ ret = mbedtls_aes_setkey_dec( &aes, buf, 256 );
+ if( ret != 0 )
+ goto exit;
+
+ 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;
+ }
+
+ ret = mbedtls_aes_crypt_ecb( &aes, MBEDTLS_AES_DECRYPT, buf, buf );
+ if( ret != 0 )
+ goto exit;
+ 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 );
+
+ mbedtls_exit( 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 */
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-13 16:36:21 +0000