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authorAndreas Schneider <asn@cynapses.org>2010-09-06 14:28:38 +0200
committerAndreas Schneider <asn@cynapses.org>2010-09-06 14:28:38 +0200
commitf7842e3a4b9acea2126ff725f993c299aef0e6db (patch)
tree18239f819a5edbcfc7f2961c48f3f9297314ef22 /src/crypt.c
parent38421403d2dc45636e597f2a909daa6ae31976de (diff)
downloadlibssh-f7842e3a4b9acea2126ff725f993c299aef0e6db.tar.gz
libssh-f7842e3a4b9acea2126ff725f993c299aef0e6db.tar.xz
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misc: Rename libssh/ to src/
Diffstat (limited to 'src/crypt.c')
-rw-r--r--src/crypt.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/src/crypt.c b/src/crypt.c
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--- /dev/null
+++ b/src/crypt.c
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+/*
+ * crypt.c - blowfish-cbc code
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2003 by Aris Adamantiadis
+ *
+ * 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.
+ */
+
+#include "config.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef _WIN32
+#include <arpa/inet.h>
+#endif
+
+#ifdef OPENSSL_CRYPTO
+#include <openssl/blowfish.h>
+#include <openssl/evp.h>
+#include <openssl/hmac.h>
+#endif
+
+#include "libssh/priv.h"
+#include "libssh/session.h"
+#include "libssh/wrapper.h"
+#include "libssh/crypto.h"
+#include "libssh/buffer.h"
+
+uint32_t packet_decrypt_len(ssh_session session, char *crypted){
+ uint32_t decrypted;
+
+ if (session->current_crypto) {
+ if (packet_decrypt(session, crypted,
+ session->current_crypto->in_cipher->blocksize) < 0) {
+ return 0;
+ }
+ }
+
+ memcpy(&decrypted,crypted,sizeof(decrypted));
+ ssh_log(session, SSH_LOG_PACKET,
+ "Packet size decrypted: %lu (0x%lx)",
+ (long unsigned int) ntohl(decrypted),
+ (long unsigned int) ntohl(decrypted));
+ return ntohl(decrypted);
+}
+
+int packet_decrypt(ssh_session session, void *data,uint32_t len) {
+ struct crypto_struct *crypto = session->current_crypto->in_cipher;
+ char *out = NULL;
+ if(len % session->current_crypto->in_cipher->blocksize != 0){
+ ssh_set_error(session, SSH_FATAL, "Cryptographic functions must be set on at least one blocksize (received %d)",len);
+ return SSH_ERROR;
+ }
+ out = malloc(len);
+ if (out == NULL) {
+ return -1;
+ }
+
+ ssh_log(session,SSH_LOG_PACKET, "Decrypting %d bytes", len);
+
+#ifdef HAVE_LIBGCRYPT
+ if (crypto->set_decrypt_key(crypto, session->current_crypto->decryptkey,
+ session->current_crypto->decryptIV) < 0) {
+ SAFE_FREE(out);
+ return -1;
+ }
+ crypto->cbc_decrypt(crypto,data,out,len);
+#elif defined HAVE_LIBCRYPTO
+ if (crypto->set_decrypt_key(crypto, session->current_crypto->decryptkey) < 0) {
+ SAFE_FREE(out);
+ return -1;
+ }
+ crypto->cbc_decrypt(crypto,data,out,len,session->current_crypto->decryptIV);
+#endif
+
+ memcpy(data,out,len);
+ memset(out,0,len);
+
+ SAFE_FREE(out);
+ return 0;
+}
+
+unsigned char *packet_encrypt(ssh_session session, void *data, uint32_t len) {
+ struct crypto_struct *crypto = NULL;
+ HMACCTX ctx = NULL;
+ char *out = NULL;
+ unsigned int finallen;
+ uint32_t seq;
+
+ if (!session->current_crypto) {
+ return NULL; /* nothing to do here */
+ }
+ if(len % session->current_crypto->in_cipher->blocksize != 0){
+ ssh_set_error(session, SSH_FATAL, "Cryptographic functions must be set on at least one blocksize (received %d)",len);
+ return NULL;
+ }
+ out = malloc(len);
+ if (out == NULL) {
+ return NULL;
+ }
+
+ seq = ntohl(session->send_seq);
+ crypto = session->current_crypto->out_cipher;
+
+ ssh_log(session, SSH_LOG_PACKET,
+ "Encrypting packet with seq num: %d, len: %d",
+ session->send_seq,len);
+
+#ifdef HAVE_LIBGCRYPT
+ if (crypto->set_encrypt_key(crypto, session->current_crypto->encryptkey,
+ session->current_crypto->encryptIV) < 0) {
+ SAFE_FREE(out);
+ return NULL;
+ }
+#elif defined HAVE_LIBCRYPTO
+ if (crypto->set_encrypt_key(crypto, session->current_crypto->encryptkey) < 0) {
+ SAFE_FREE(out);
+ return NULL;
+ }
+#endif
+
+ if (session->version == 2) {
+ ctx = hmac_init(session->current_crypto->encryptMAC,20,HMAC_SHA1);
+ if (ctx == NULL) {
+ SAFE_FREE(out);
+ return NULL;
+ }
+ hmac_update(ctx,(unsigned char *)&seq,sizeof(uint32_t));
+ hmac_update(ctx,data,len);
+ hmac_final(ctx,session->current_crypto->hmacbuf,&finallen);
+#ifdef DEBUG_CRYPTO
+ ssh_print_hexa("mac: ",data,len);
+ if (finallen != 20) {
+ printf("Final len is %d\n",finallen);
+ }
+ ssh_print_hexa("Packet hmac", session->current_crypto->hmacbuf, 20);
+#endif
+ }
+
+#ifdef HAVE_LIBGCRYPT
+ crypto->cbc_encrypt(crypto, data, out, len);
+#elif defined HAVE_LIBCRYPTO
+ crypto->cbc_encrypt(crypto, data, out, len,
+ session->current_crypto->encryptIV);
+#endif
+
+ memcpy(data, out, len);
+ memset(out, 0, len);
+ SAFE_FREE(out);
+
+ if (session->version == 2) {
+ return session->current_crypto->hmacbuf;
+ }
+
+ return NULL;
+}
+
+/**
+ * @internal
+ *
+ * @brief Verify the hmac of a packet
+ *
+ * @param session The session to use.
+ * @param buffer The buffer to verify the hmac from.
+ * @param mac The mac to compare with the hmac.
+ *
+ * @return 0 if hmac and mac are equal, < 0 if not or an error
+ * occurred.
+ */
+int packet_hmac_verify(ssh_session session, ssh_buffer buffer,
+ unsigned char *mac) {
+ unsigned char hmacbuf[EVP_MAX_MD_SIZE] = {0};
+ HMACCTX ctx;
+ unsigned int len;
+ uint32_t seq;
+
+ ctx = hmac_init(session->current_crypto->decryptMAC, 20, HMAC_SHA1);
+ if (ctx == NULL) {
+ return -1;
+ }
+
+ seq = htonl(session->recv_seq);
+
+ hmac_update(ctx, (unsigned char *) &seq, sizeof(uint32_t));
+ hmac_update(ctx, ssh_buffer_get_begin(buffer), ssh_buffer_get_len(buffer));
+ hmac_final(ctx, hmacbuf, &len);
+
+#ifdef DEBUG_CRYPTO
+ ssh_print_hexa("received mac",mac,len);
+ ssh_print_hexa("Computed mac",hmacbuf,len);
+ ssh_print_hexa("seq",(unsigned char *)&seq,sizeof(uint32_t));
+#endif
+ if (memcmp(mac, hmacbuf, len) == 0) {
+ return 0;
+ }
+
+ return -1;
+}
+
+/* vim: set ts=2 sw=2 et cindent: */