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-rw-r--r--libssh/dh.c1049
1 files changed, 0 insertions, 1049 deletions
diff --git a/libssh/dh.c b/libssh/dh.c
deleted file mode 100644
index 74d799e6..00000000
--- a/libssh/dh.c
+++ /dev/null
@@ -1,1049 +0,0 @@
-/*
- * dh.c - Diffie-Helman algorithm code against SSH 2
- *
- * This file is part of the SSH Library
- *
- * Copyright (c) 2003-2008 by Aris Adamantiadis
- * Copyright (c) 2009 by Andreas Schneider <mail@cynapses.org>
- *
- * The SSH Library is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or (at your
- * option) any later version.
- *
- * The SSH Library is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
- * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
- * License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with the SSH Library; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
- * MA 02111-1307, USA.
- */
-
-/*
- * Let us resume the dh protocol.
- * Each side computes a private prime number, x at client side, y at server
- * side.
- * g and n are two numbers common to every ssh software.
- * client's public key (e) is calculated by doing:
- * e = g^x mod p
- * client sends e to the server.
- * the server computes his own public key, f
- * f = g^y mod p
- * it sends it to the client
- * the common key K is calculated by the client by doing
- * k = f^x mod p
- * the server does the same with the client public key e
- * k' = e^y mod p
- * if everything went correctly, k and k' are equal
- */
-
-#include "config.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#ifndef _WIN32
-#include <arpa/inet.h>
-#endif
-
-#include "libssh/priv.h"
-#include "libssh/crypto.h"
-#include "libssh/buffer.h"
-#include "libssh/session.h"
-#include "libssh/keys.h"
-#include "libssh/dh.h"
-
-/* todo: remove it */
-#include "libssh/string.h"
-#ifdef HAVE_LIBCRYPTO
-#include <openssl/rand.h>
-#include <openssl/evp.h>
-#include <openssl/err.h>
-#endif
-
-static unsigned char p_value[] = {
- 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xC9, 0x0F, 0xDA, 0xA2,
- 0x21, 0x68, 0xC2, 0x34, 0xC4, 0xC6, 0x62, 0x8B, 0x80, 0xDC, 0x1C, 0xD1,
- 0x29, 0x02, 0x4E, 0x08, 0x8A, 0x67, 0xCC, 0x74, 0x02, 0x0B, 0xBE, 0xA6,
- 0x3B, 0x13, 0x9B, 0x22, 0x51, 0x4A, 0x08, 0x79, 0x8E, 0x34, 0x04, 0xDD,
- 0xEF, 0x95, 0x19, 0xB3, 0xCD, 0x3A, 0x43, 0x1B, 0x30, 0x2B, 0x0A, 0x6D,
- 0xF2, 0x5F, 0x14, 0x37, 0x4F, 0xE1, 0x35, 0x6D, 0x6D, 0x51, 0xC2, 0x45,
- 0xE4, 0x85, 0xB5, 0x76, 0x62, 0x5E, 0x7E, 0xC6, 0xF4, 0x4C, 0x42, 0xE9,
- 0xA6, 0x37, 0xED, 0x6B, 0x0B, 0xFF, 0x5C, 0xB6, 0xF4, 0x06, 0xB7, 0xED,
- 0xEE, 0x38, 0x6B, 0xFB, 0x5A, 0x89, 0x9F, 0xA5, 0xAE, 0x9F, 0x24, 0x11,
- 0x7C, 0x4B, 0x1F, 0xE6, 0x49, 0x28, 0x66, 0x51, 0xEC, 0xE6, 0x53, 0x81,
- 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
-#define P_LEN 128 /* Size in bytes of the p number */
-
-static unsigned long g_int = 2 ; /* G is defined as 2 by the ssh2 standards */
-static bignum g;
-static bignum p;
-static int ssh_crypto_initialized;
-
-int ssh_get_random(void *where, int len, int strong){
-
-#ifdef HAVE_LIBGCRYPT
- /* variable not used in gcrypt */
- (void) strong;
- /* not using GCRY_VERY_STRONG_RANDOM which is a bit overkill */
- gcry_randomize(where,len,GCRY_STRONG_RANDOM);
-
- return 1;
-#elif defined HAVE_LIBCRYPTO
- if (strong) {
- return RAND_bytes(where,len);
- } else {
- return RAND_pseudo_bytes(where,len);
- }
-#endif
-
- /* never reached */
- return 1;
-}
-
-/*
- * This inits the values g and p which are used for DH key agreement
- * FIXME: Make the function thread safe by adding a semaphore or mutex.
- */
-int ssh_crypto_init(void) {
- if (ssh_crypto_initialized == 0) {
-#ifdef HAVE_LIBGCRYPT
- gcry_check_version(NULL);
- if (!gcry_control(GCRYCTL_INITIALIZATION_FINISHED_P,0)) {
- gcry_control(GCRYCTL_INIT_SECMEM, 4096);
- gcry_control(GCRYCTL_INITIALIZATION_FINISHED,0);
- }
-#endif
-
- g = bignum_new();
- if (g == NULL) {
- return -1;
- }
- bignum_set_word(g,g_int);
-
-#ifdef HAVE_LIBGCRYPT
- bignum_bin2bn(p_value, P_LEN, &p);
- if (p == NULL) {
- bignum_free(g);
- g = NULL;
- return -1;
- }
-#elif defined HAVE_LIBCRYPTO
- p = bignum_new();
- if (p == NULL) {
- bignum_free(g);
- g = NULL;
- return -1;
- }
- bignum_bin2bn(p_value, P_LEN, p);
- OpenSSL_add_all_algorithms();
-#endif
-
- ssh_crypto_initialized = 1;
- }
-
- return 0;
-}
-
-void ssh_crypto_finalize(void) {
- if (ssh_crypto_initialized) {
- bignum_free(g);
- g = NULL;
- bignum_free(p);
- p = NULL;
- ssh_crypto_initialized=0;
-
- }
-}
-
-/* prints the bignum on stderr */
-void ssh_print_bignum(const char *which, bignum num) {
-#ifdef HAVE_LIBGCRYPT
- unsigned char *hex = NULL;
- bignum_bn2hex(num, &hex);
-#elif defined HAVE_LIBCRYPTO
- char *hex = NULL;
- hex = bignum_bn2hex(num);
-#endif
- fprintf(stderr, "%s value: ", which);
- fprintf(stderr, "%s\n", (hex == NULL) ? "(null)" : (char *) hex);
- SAFE_FREE(hex);
-}
-
-/**
- * @brief Convert a buffer into a colon separated hex string.
- * The caller has to free the memory.
- *
- * @param what What should be converted to a hex string.
- *
- * @param len Length of the buffer to convert.
- *
- * @return The hex string or NULL on error.
- */
-char *ssh_get_hexa(const unsigned char *what, size_t len) {
- char *hexa = NULL;
- size_t i;
-
- hexa = malloc(len * 3 + 1);
- if (hexa == NULL) {
- return NULL;
- }
-
- ZERO_STRUCTP(hexa);
-
- for (i = 0; i < len; i++) {
- char hex[4];
- snprintf(hex, sizeof(hex), "%02x:", what[i]);
- strcat(hexa, hex);
- }
-
- hexa[(len * 3) - 1] = '\0';
-
- return hexa;
-}
-
-/**
- * @brief Print a buffer as colon separated hex string.
- *
- * @param descr Description printed in front of the hex string.
- *
- * @param what What should be converted to a hex string.
- *
- * @param len Length of the buffer to convert.
- */
-void ssh_print_hexa(const char *descr, const unsigned char *what, size_t len) {
- char *hexa = ssh_get_hexa(what, len);
-
- if (hexa == NULL) {
- return;
- }
- printf("%s: %s\n", descr, hexa);
-}
-
-int dh_generate_x(ssh_session session) {
- session->next_crypto->x = bignum_new();
- if (session->next_crypto->x == NULL) {
- return -1;
- }
-
-#ifdef HAVE_LIBGCRYPT
- bignum_rand(session->next_crypto->x, 128);
-#elif defined HAVE_LIBCRYPTO
- bignum_rand(session->next_crypto->x, 128, 0, -1);
-#endif
-
- /* not harder than this */
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("x", session->next_crypto->x);
-#endif
-
- return 0;
-}
-
-/* used by server */
-int dh_generate_y(ssh_session session) {
- session->next_crypto->y = bignum_new();
- if (session->next_crypto->y == NULL) {
- return -1;
- }
-
-#ifdef HAVE_LIBGCRYPT
- bignum_rand(session->next_crypto->y, 128);
-#elif defined HAVE_LIBCRYPTO
- bignum_rand(session->next_crypto->y, 128, 0, -1);
-#endif
-
- /* not harder than this */
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("y", session->next_crypto->y);
-#endif
-
- return 0;
-}
-
-/* used by server */
-int dh_generate_e(ssh_session session) {
-#ifdef HAVE_LIBCRYPTO
- bignum_CTX ctx = bignum_ctx_new();
- if (ctx == NULL) {
- return -1;
- }
-#endif
-
- session->next_crypto->e = bignum_new();
- if (session->next_crypto->e == NULL) {
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
- return -1;
- }
-
-#ifdef HAVE_LIBGCRYPT
- bignum_mod_exp(session->next_crypto->e, g, session->next_crypto->x, p);
-#elif defined HAVE_LIBCRYPTO
- bignum_mod_exp(session->next_crypto->e, g, session->next_crypto->x, p, ctx);
-#endif
-
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("e", session->next_crypto->e);
-#endif
-
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
-
- return 0;
-}
-
-int dh_generate_f(ssh_session session) {
-#ifdef HAVE_LIBCRYPTO
- bignum_CTX ctx = bignum_ctx_new();
- if (ctx == NULL) {
- return -1;
- }
-#endif
-
- session->next_crypto->f = bignum_new();
- if (session->next_crypto->f == NULL) {
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
- return -1;
- }
-
-#ifdef HAVE_LIBGCRYPT
- bignum_mod_exp(session->next_crypto->f, g, session->next_crypto->y, p);
-#elif defined HAVE_LIBCRYPTO
- bignum_mod_exp(session->next_crypto->f, g, session->next_crypto->y, p, ctx);
-#endif
-
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("f", session->next_crypto->f);
-#endif
-
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
-
- return 0;
-}
-
-ssh_string make_bignum_string(bignum num) {
- ssh_string ptr = NULL;
- int pad = 0;
- unsigned int len = bignum_num_bytes(num);
- unsigned int bits = bignum_num_bits(num);
-
- /* Remember if the fist bit is set, it is considered as a
- * negative number. So 0's must be appended */
- if (!(bits % 8) && bignum_is_bit_set(num, bits - 1)) {
- pad++;
- }
-
-#ifdef DEBUG_CRYPTO
- fprintf(stderr, "%d bits, %d bytes, %d padding\n", bits, len, pad);
-#endif /* DEBUG_CRYPTO */
-/* TODO: fix that crap !! */
- ptr = malloc(4 + len + pad);
- if (ptr == NULL) {
- return NULL;
- }
- ptr->size = htonl(len + pad);
- if (pad) {
- ptr->string[0] = 0;
- }
-
-#ifdef HAVE_LIBGCRYPT
- bignum_bn2bin(num, len, ptr->string + pad);
-#elif HAVE_LIBCRYPTO
- bignum_bn2bin(num, ptr->string + pad);
-#endif
-
- return ptr;
-}
-
-bignum make_string_bn(ssh_string string){
- bignum bn = NULL;
- unsigned int len = ssh_string_len(string);
-
-#ifdef DEBUG_CRYPTO
- fprintf(stderr, "Importing a %d bits, %d bytes object ...\n",
- len * 8, len);
-#endif /* DEBUG_CRYPTO */
-
-#ifdef HAVE_LIBGCRYPT
- bignum_bin2bn(string->string, len, &bn);
-#elif defined HAVE_LIBCRYPTO
- bn = bignum_bin2bn(string->string, len, NULL);
-#endif
-
- return bn;
-}
-
-ssh_string dh_get_e(ssh_session session) {
- return make_bignum_string(session->next_crypto->e);
-}
-
-/* used by server */
-ssh_string dh_get_f(ssh_session session) {
- return make_bignum_string(session->next_crypto->f);
-}
-
-void dh_import_pubkey(ssh_session session, ssh_string pubkey_string) {
- session->next_crypto->server_pubkey = pubkey_string;
-}
-
-int dh_import_f(ssh_session session, ssh_string f_string) {
- session->next_crypto->f = make_string_bn(f_string);
- if (session->next_crypto->f == NULL) {
- return -1;
- }
-
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("f",session->next_crypto->f);
-#endif
-
- return 0;
-}
-
-/* used by the server implementation */
-int dh_import_e(ssh_session session, ssh_string e_string) {
- session->next_crypto->e = make_string_bn(e_string);
- if (session->next_crypto->e == NULL) {
- return -1;
- }
-
-#ifdef DEBUG_CRYPTO
- ssh_print_bignum("e",session->next_crypto->e);
-#endif
-
- return 0;
-}
-
-int dh_build_k(ssh_session session) {
-#ifdef HAVE_LIBCRYPTO
- bignum_CTX ctx = bignum_ctx_new();
- if (ctx == NULL) {
- return -1;
- }
-#endif
-
- session->next_crypto->k = bignum_new();
- if (session->next_crypto->k == NULL) {
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
- return -1;
- }
-
- /* the server and clients don't use the same numbers */
-#ifdef HAVE_LIBGCRYPT
- if(session->client) {
- bignum_mod_exp(session->next_crypto->k, session->next_crypto->f,
- session->next_crypto->x, p);
- } else {
- bignum_mod_exp(session->next_crypto->k, session->next_crypto->e,
- session->next_crypto->y, p);
- }
-#elif defined HAVE_LIBCRYPTO
- if (session->client) {
- bignum_mod_exp(session->next_crypto->k, session->next_crypto->f,
- session->next_crypto->x, p, ctx);
- } else {
- bignum_mod_exp(session->next_crypto->k, session->next_crypto->e,
- session->next_crypto->y, p, ctx);
- }
-#endif
-
-#ifdef DEBUG_CRYPTO
- ssh_print_hexa("Session server cookie", session->server_kex.cookie, 16);
- ssh_print_hexa("Session client cookie", session->client_kex.cookie, 16);
- ssh_print_bignum("Shared secret key", session->next_crypto->k);
-#endif
-
-#ifdef HAVE_LIBCRYPTO
- bignum_ctx_free(ctx);
-#endif
-
- return 0;
-}
-
-/*
-static void sha_add(ssh_string str,SHACTX ctx){
- sha1_update(ctx,str,string_len(str)+4);
-#ifdef DEBUG_CRYPTO
- ssh_print_hexa("partial hashed sessionid",str,string_len(str)+4);
-#endif
-}
-*/
-
-int make_sessionid(ssh_session session) {
- SHACTX ctx;
- ssh_string num = NULL;
- ssh_string str = NULL;
- ssh_buffer server_hash = NULL;
- ssh_buffer client_hash = NULL;
- ssh_buffer buf = NULL;
- uint32_t len;
- int rc = SSH_ERROR;
-
- enter_function();
-
- ctx = sha1_init();
- if (ctx == NULL) {
- return rc;
- }
-
- buf = ssh_buffer_new();
- if (buf == NULL) {
- return rc;
- }
-
- str = ssh_string_from_char(session->clientbanner);
- if (str == NULL) {
- goto error;
- }
-
- if (buffer_add_ssh_string(buf, str) < 0) {
- goto error;
- }
- ssh_string_free(str);
-
- str = ssh_string_from_char(session->serverbanner);
- if (str == NULL) {
- goto error;
- }
-
- if (buffer_add_ssh_string(buf, str) < 0) {
- goto error;
- }
-
- if (session->client) {
- server_hash = session->in_hashbuf;
- client_hash = session->out_hashbuf;
- } else {
- server_hash = session->out_hashbuf;
- client_hash = session->in_hashbuf;
- }
-
- if (buffer_add_u32(server_hash, 0) < 0) {
- goto error;
- }
- if (buffer_add_u8(server_hash, 0) < 0) {
- goto error;
- }
- if (buffer_add_u32(client_hash, 0) < 0) {
- goto error;
- }
- if (buffer_add_u8(client_hash, 0) < 0) {
- goto error;
- }
-
- len = ntohl(ssh_buffer_get_len(client_hash));
- if (buffer_add_u32(buf,len) < 0) {
- goto error;
- }
- if (buffer_add_data(buf, ssh_buffer_get_begin(client_hash),
- ssh_buffer_get_len(client_hash)) < 0) {
- goto error;
- }
-
- len = ntohl(ssh_buffer_get_len(server_hash));
- if (buffer_add_u32(buf, len) < 0) {
- goto error;
- }
- if (buffer_add_data(buf, ssh_buffer_get_begin(server_hash),
- ssh_buffer_get_len(server_hash)) < 0) {
- goto error;
- }
-
- len = ssh_string_len(session->next_crypto->server_pubkey) + 4;
- if (buffer_add_data(buf, session->next_crypto->server_pubkey, len) < 0) {
- goto error;
- }
-
- num = make_bignum_string(session->next_crypto->e);
- if (num == NULL) {
- goto error;
- }
-
- len = ssh_string_len(num) + 4;
- if (buffer_add_data(buf, num, len) < 0) {
- goto error;
- }
-
- ssh_string_free(num);
- num = make_bignum_string(session->next_crypto->f);
- if (num == NULL) {
- goto error;
- }
-
- len = ssh_string_len(num) + 4;
- if (buffer_add_data(buf, num, len) < 0) {
- goto error;
- }
-
- ssh_string_free(num);
- num = make_bignum_string(session->next_crypto->k);
- if (num == NULL) {
- goto error;
- }
-
- len = ssh_string_len(num) + 4;
- if (buffer_add_data(buf, num, len) < 0) {
- goto error;
- }
-
-#ifdef DEBUG_CRYPTO
- ssh_print_hexa("hash buffer", ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
-#endif
-
- sha1_update(ctx, ssh_buffer_get_begin(buf), ssh_buffer_get_len(buf));
- sha1_final(session->next_crypto->session_id, ctx);
-
-#ifdef DEBUG_CRYPTO
- printf("Session hash: ");
- ssh_print_hexa("session id", session->next_crypto->session_id, SHA_DIGEST_LEN);
-#endif
-
- rc = SSH_OK;
-error:
- ssh_buffer_free(buf);
- ssh_buffer_free(client_hash);
- ssh_buffer_free(server_hash);
-
- session->in_hashbuf = NULL;
- session->out_hashbuf = NULL;
-
- ssh_string_free(str);
- ssh_string_free(num);
-
- leave_function();
-
- return rc;
-}
-
-int hashbufout_add_cookie(ssh_session session) {
- session->out_hashbuf = ssh_buffer_new();
- if (session->out_hashbuf == NULL) {
- return -1;
- }
-
- if (buffer_add_u8(session->out_hashbuf, 20) < 0) {
- buffer_reinit(session->out_hashbuf);
- return -1;
- }
-
- if (session->server) {
- if (buffer_add_data(session->out_hashbuf,
- session->server_kex.cookie, 16) < 0) {
- buffer_reinit(session->out_hashbuf);
- return -1;
- }
- } else {
- if (buffer_add_data(session->out_hashbuf,
- session->client_kex.cookie, 16) < 0) {
- buffer_reinit(session->out_hashbuf);
- return -1;
- }
- }
-
- return 0;
-}
-
-int hashbufin_add_cookie(ssh_session session, unsigned char *cookie) {
- session->in_hashbuf = ssh_buffer_new();
- if (session->in_hashbuf == NULL) {
- return -1;
- }
-
- if (buffer_add_u8(session->in_hashbuf, 20) < 0) {
- buffer_reinit(session->in_hashbuf);
- return -1;
- }
- if (buffer_add_data(session->in_hashbuf,cookie, 16) < 0) {
- buffer_reinit(session->in_hashbuf);
- return -1;
- }
-
- return 0;
-}
-
-static int generate_one_key(ssh_string k,
- unsigned char session_id[SHA_DIGEST_LEN],
- unsigned char output[SHA_DIGEST_LEN],
- char letter) {
- SHACTX ctx = NULL;
-
- ctx = sha1_init();
- if (ctx == NULL) {
- return -1;
- }
-
- sha1_update(ctx, k, ssh_string_len(k) + 4);
- sha1_update(ctx, session_id, SHA_DIGEST_LEN);
- sha1_update(ctx, &letter, 1);
- sha1_update(ctx, session_id, SHA_DIGEST_LEN);
- sha1_final(output, ctx);
-
- return 0;
-}
-
-int generate_session_keys(ssh_session session) {
- ssh_string k_string = NULL;
- SHACTX ctx = NULL;
- int rc = -1;
-
- enter_function();
-
- k_string = make_bignum_string(session->next_crypto->k);
- if (k_string == NULL) {
- goto error;
- }
-
- /* IV */
- if (session->client) {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptIV, 'A') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptIV, 'B') < 0) {
- goto error;
- }
- } else {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptIV, 'A') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptIV, 'B') < 0) {
- goto error;
- }
- }
- if (session->client) {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptkey, 'C') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptkey, 'D') < 0) {
- goto error;
- }
- } else {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptkey, 'C') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptkey, 'D') < 0) {
- goto error;
- }
- }
-
- /* some ciphers need more than 20 bytes of input key */
- /* XXX verify it's ok for server implementation */
- if (session->next_crypto->out_cipher->keysize > SHA_DIGEST_LEN * 8) {
- ctx = sha1_init();
- if (ctx == NULL) {
- goto error;
- }
- sha1_update(ctx, k_string, ssh_string_len(k_string) + 4);
- sha1_update(ctx, session->next_crypto->session_id, SHA_DIGEST_LEN);
- sha1_update(ctx, session->next_crypto->encryptkey, SHA_DIGEST_LEN);
- sha1_final(session->next_crypto->encryptkey + SHA_DIGEST_LEN, ctx);
- }
-
- if (session->next_crypto->in_cipher->keysize > SHA_DIGEST_LEN * 8) {
- ctx = sha1_init();
- sha1_update(ctx, k_string, ssh_string_len(k_string) + 4);
- sha1_update(ctx, session->next_crypto->session_id, SHA_DIGEST_LEN);
- sha1_update(ctx, session->next_crypto->decryptkey, SHA_DIGEST_LEN);
- sha1_final(session->next_crypto->decryptkey + SHA_DIGEST_LEN, ctx);
- }
- if(session->client) {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptMAC, 'E') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptMAC, 'F') < 0) {
- goto error;
- }
- } else {
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->decryptMAC, 'E') < 0) {
- goto error;
- }
- if (generate_one_key(k_string, session->next_crypto->session_id,
- session->next_crypto->encryptMAC, 'F') < 0) {
- goto error;
- }
- }
-
-#ifdef DEBUG_CRYPTO
- ssh_print_hexa("Encrypt IV", session->next_crypto->encryptIV, SHA_DIGEST_LEN);
- ssh_print_hexa("Decrypt IV", session->next_crypto->decryptIV, SHA_DIGEST_LEN);
- ssh_print_hexa("Encryption key", session->next_crypto->encryptkey,
- session->next_crypto->out_cipher->keysize);
- ssh_print_hexa("Decryption key", session->next_crypto->decryptkey,
- session->next_crypto->in_cipher->keysize);
- ssh_print_hexa("Encryption MAC", session->next_crypto->encryptMAC, SHA_DIGEST_LEN);
- ssh_print_hexa("Decryption MAC", session->next_crypto->decryptMAC, 20);
-#endif
-
- rc = 0;
-error:
- ssh_string_free(k_string);
- leave_function();
-
- return rc;
-}
-
-/**
- * @addtogroup libssh_session
- *
- * @{
- */
-
-/**
- * @brief Allocates a buffer with the MD5 hash of the server public key.
- *
- * @param[in] session The SSH session to use.
- *
- * @param[in] hash The buffer to allocate.
- *
- * @return The bytes allocated or < 0 on error.
- *
- * @warning It is very important that you verify at some moment that the hash
- * matches a known server. If you don't do it, cryptography wont help
- * you at making things secure
- *
- * @see ssh_is_server_known()
- * @see ssh_get_hexa()
- * @see ssh_print_hexa()
- */
-int ssh_get_pubkey_hash(ssh_session session, unsigned char **hash) {
- ssh_string pubkey;
- MD5CTX ctx;
- unsigned char *h;
-
- if (session == NULL || hash == NULL) {
- return -1;
- }
- *hash = NULL;
- if (session->current_crypto == NULL ||
- session->current_crypto->server_pubkey == NULL){
- ssh_set_error(session,SSH_FATAL,"No current cryptographic context");
- }
-
- h = malloc(sizeof(unsigned char *) * MD5_DIGEST_LEN);
- if (h == NULL) {
- return -1;
- }
-
- ctx = md5_init();
- if (ctx == NULL) {
- SAFE_FREE(h);
- return -1;
- }
-
- pubkey = session->current_crypto->server_pubkey;
-
- md5_update(ctx, pubkey->string, ssh_string_len(pubkey));
- md5_final(h, ctx);
-
- *hash = h;
-
- return MD5_DIGEST_LEN;
-}
-
-/**
- * @brief Deallocate the hash obtained by ssh_get_pubkey_hash.
- *
- * This is required under Microsoft platform as this library might use a
- * different C library than your software, hence a different heap.
- *
- * @param[in] hash The buffer to deallocate.
- *
- * @see ssh_get_pubkey_hash()
- */
-void ssh_clean_pubkey_hash(unsigned char **hash) {
- SAFE_FREE(*hash);
- *hash = NULL;
-}
-
-ssh_string ssh_get_pubkey(ssh_session session){
- return ssh_string_copy(session->current_crypto->server_pubkey);
-}
-
-static int match(const char *group, const char *object){
- const char *a;
- const char *z;
-
- z = group;
- do {
- a = strchr(z, ',');
- if (a == NULL) {
- if (strcmp(z, object) == 0) {
- return 1;
- }
- return 0;
- } else {
- if (strncmp(z, object, a - z) == 0) {
- return 1;
- }
- }
- z = a + 1;
- } while(1);
-
- /* not reached */
- return 0;
-}
-
-int sig_verify(ssh_session session, ssh_public_key pubkey,
- SIGNATURE *signature, unsigned char *digest, int size) {
-#ifdef HAVE_LIBGCRYPT
- gcry_error_t valid = 0;
- gcry_sexp_t gcryhash;
-#elif defined HAVE_LIBCRYPTO
- int valid = 0;
-#endif
- unsigned char hash[SHA_DIGEST_LEN + 1] = {0};
-
- sha1(digest, size, hash + 1);
-
-#ifdef DEBUG_CRYPTO
- ssh_print_hexa("Hash to be verified with dsa", hash + 1, SHA_DIGEST_LEN);
-#endif
-
- switch(pubkey->type) {
- case SSH_KEYTYPE_DSS:
-#ifdef HAVE_LIBGCRYPT
- valid = gcry_sexp_build(&gcryhash, NULL, "%b", SHA_DIGEST_LEN + 1, hash);
- if (valid != 0) {
- ssh_set_error(session, SSH_FATAL,
- "RSA error: %s", gcry_strerror(valid));
- return -1;
- }
- valid = gcry_pk_verify(signature->dsa_sign, gcryhash, pubkey->dsa_pub);
- gcry_sexp_release(gcryhash);
- if (valid == 0) {
- return 0;
- }
-
- if (gcry_err_code(valid) != GPG_ERR_BAD_SIGNATURE) {
- ssh_set_error(session, SSH_FATAL,
- "DSA error: %s", gcry_strerror(valid));
- return -1;
- }
-#elif defined HAVE_LIBCRYPTO
- valid = DSA_do_verify(hash + 1, SHA_DIGEST_LEN, signature->dsa_sign,
- pubkey->dsa_pub);
- if (valid == 1) {
- return 0;
- }
-
- if (valid == -1) {
- ssh_set_error(session, SSH_FATAL,
- "DSA error: %s", ERR_error_string(ERR_get_error(), NULL));
- return -1;
- }
-#endif
- ssh_set_error(session, SSH_FATAL, "Invalid DSA signature");
- return -1;
-
- case SSH_KEYTYPE_RSA:
- case SSH_KEYTYPE_RSA1:
-#ifdef HAVE_LIBGCRYPT
- valid = gcry_sexp_build(&gcryhash, NULL,
- "(data(flags pkcs1)(hash sha1 %b))", SHA_DIGEST_LEN, hash + 1);
- if (valid != 0) {
- ssh_set_error(session, SSH_FATAL,
- "RSA error: %s", gcry_strerror(valid));
- return -1;
- }
- valid = gcry_pk_verify(signature->rsa_sign,gcryhash,pubkey->rsa_pub);
- gcry_sexp_release(gcryhash);
- if (valid == 0) {
- return 0;
- }
- if (gcry_err_code(valid) != GPG_ERR_BAD_SIGNATURE) {
- ssh_set_error(session, SSH_FATAL,
- "RSA error: %s", gcry_strerror(valid));
- return -1;
- }
-#elif defined HAVE_LIBCRYPTO
- valid = RSA_verify(NID_sha1, hash + 1, SHA_DIGEST_LEN,
- signature->rsa_sign->string, ssh_string_len(signature->rsa_sign),
- pubkey->rsa_pub);
- if (valid == 1) {
- return 0;
- }
- if (valid == -1) {
- ssh_set_error(session, SSH_FATAL,
- "RSA error: %s", ERR_error_string(ERR_get_error(), NULL));
- return -1;
- }
-#endif
- ssh_set_error(session, SSH_FATAL, "Invalid RSA signature");
- return -1;
- default:
- ssh_set_error(session, SSH_FATAL, "Unknown public key type");
- return -1;
- }
-
- return -1;
-}
-
-int signature_verify(ssh_session session, ssh_string signature) {
- ssh_public_key pubkey = NULL;
- SIGNATURE *sign = NULL;
- int err;
-
- enter_function();
-
- pubkey = publickey_from_string(session,session->next_crypto->server_pubkey);
- if(pubkey == NULL) {
- leave_function();
- return -1;
- }
-
- if (session->wanted_methods[SSH_HOSTKEYS]) {
- if(!match(session->wanted_methods[SSH_HOSTKEYS],pubkey->type_c)) {
- ssh_set_error(session, SSH_FATAL,
- "Public key from server (%s) doesn't match user preference (%s)",
- pubkey->type_c, session->wanted_methods[SSH_HOSTKEYS]);
- publickey_free(pubkey);
- leave_function();
- return -1;
- }
- }
-
- sign = signature_from_string(session, signature, pubkey, pubkey->type);
- if (sign == NULL) {
- ssh_set_error(session, SSH_FATAL, "Invalid signature blob");
- publickey_free(pubkey);
- leave_function();
- return -1;
- }
-
- ssh_log(session, SSH_LOG_FUNCTIONS,
- "Going to verify a %s type signature", pubkey->type_c);
-
- err = sig_verify(session,pubkey,sign,
- session->next_crypto->session_id,SHA_DIGEST_LEN);
- signature_free(sign);
- session->next_crypto->server_pubkey_type = pubkey->type_c;
- publickey_free(pubkey);
-
- leave_function();
- return err;
-}
-
-/** @} */
-
-/* vim: set ts=4 sw=4 et cindent: */