diff options
Diffstat (limited to 'programs/pkey/dh_server.c')
| -rw-r--r-- | programs/pkey/dh_server.c | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/programs/pkey/dh_server.c b/programs/pkey/dh_server.c new file mode 100644 index 00000000000..1ae5651ba9a --- /dev/null +++ b/programs/pkey/dh_server.c @@ -0,0 +1,306 @@ +/* + * Diffie-Hellman-Merkle key exchange (server side) + * + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#include "mbedtls/build_info.h" + +#include "mbedtls/platform.h" +/* md.h is included this early since MD_CAN_XXX macros are defined there. */ +#include "mbedtls/md.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) +#include "mbedtls/net_sockets.h" +#include "mbedtls/aes.h" +#include "mbedtls/dhm.h" +#include "mbedtls/rsa.h" +#include "mbedtls/sha256.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) +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_MD_CAN_SHA256 and/or MBEDTLS_FS_IO and/or " + "MBEDTLS_CTR_DRBG_C and/or MBEDTLS_SHA1_C not defined.\n"); + mbedtls_exit(0); +} +#else + + +int main(void) +{ + FILE *f; + + int ret = 1; + int exit_code = MBEDTLS_EXIT_FAILURE; + unsigned int mdlen; + size_t n, buflen; + mbedtls_net_context listen_fd, client_fd; + + unsigned char buf[2048]; + unsigned char hash[MBEDTLS_MD_MAX_SIZE]; + 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, dhm_P, dhm_G; + + mbedtls_net_init(&listen_fd); + mbedtls_net_init(&client_fd); + 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); mbedtls_mpi_init(&dhm_P); + mbedtls_mpi_init(&dhm_G); + /* + * 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); + + 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 ((ret = mbedtls_mpi_read_file(&dhm_P, 16, f)) != 0 || + (ret = mbedtls_mpi_read_file(&dhm_G, 16, f)) != 0 || + (ret = mbedtls_dhm_set_group(&dhm, &dhm_P, &dhm_G) != 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_dhm_get_len(&dhm), 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 + */ + + mdlen = (unsigned int) mbedtls_md_get_size(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256)); + if (mdlen == 0) { + mbedtls_printf(" failed\n ! Invalid digest type\n\n"); + goto exit; + } + + if ((ret = mbedtls_sha256(buf, n, hash, 0)) != 0) { + mbedtls_printf(" failed\n ! mbedtls_sha256 returned %d\n\n", ret); + goto exit; + } + + const size_t rsa_key_len = mbedtls_rsa_get_len(&rsa); + buf[n] = (unsigned char) (rsa_key_len >> 8); + buf[n + 1] = (unsigned char) (rsa_key_len); + + if ((ret = mbedtls_rsa_pkcs1_sign(&rsa, mbedtls_ctr_drbg_random, &ctr_drbg, + MBEDTLS_MD_SHA256, mdlen, + hash, buf + n + 2)) != 0) { + mbedtls_printf(" failed\n ! mbedtls_rsa_pkcs1_sign returned %d\n\n", ret); + goto exit; + } + + buflen = n + 2 + rsa_key_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 = mbedtls_dhm_get_len(&dhm); + 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, n)) != 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); + + ret = mbedtls_aes_setkey_enc(&aes, buf, 256); + if (ret != 0) { + goto exit; + } + memcpy(buf, PLAINTEXT, 16); + ret = mbedtls_aes_crypt_ecb(&aes, MBEDTLS_AES_ENCRYPT, buf, buf); + if (ret != 0) { + goto exit; + } + + 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_mpi_free(&dhm_P); + mbedtls_mpi_free(&dhm_G); + + 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); + + mbedtls_exit(exit_code); +} +#endif /* MBEDTLS_AES_C && MBEDTLS_DHM_C && MBEDTLS_ENTROPY_C && + MBEDTLS_NET_C && MBEDTLS_RSA_C && MBEDTLS_MD_CAN_SHA256 && + MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */ |