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authorAris Adamantiadis <aris@0xbadc0de.be>2005-07-05 01:21:44 +0000
committerAris Adamantiadis <aris@0xbadc0de.be>2005-07-05 01:21:44 +0000
commitc65f56aefa50a2e2a78a0e45564526ecc921d74f (patch)
tree11bd53cf92869ccbab30f29253ce30f7078a4a26 /libssh/crypt.c
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first import
git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@1 7dcaeef0-15fb-0310-b436-a5af3365683c
Diffstat (limited to 'libssh/crypt.c')
-rw-r--r--libssh/crypt.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/libssh/crypt.c b/libssh/crypt.c
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+++ b/libssh/crypt.c
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+/* crypt.c */
+/* it just contains the shit necessary to make blowfish-cbc work ... */
+/*
+Copyright 2003 Aris Adamantiadis
+
+This file is part of the SSH Library
+
+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 <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <openssl/blowfish.h>
+#include <openssl/evp.h>
+#include <openssl/hmac.h>
+
+#include <netdb.h>
+#include "libssh/priv.h"
+#include "libssh/crypto.h"
+
+u32 packet_decrypt_len(SSH_SESSION *session, char *crypted){
+ u32 *decrypted;
+ if(session->current_crypto)
+ packet_decrypt(session,crypted,session->current_crypto->in_cipher->blocksize);
+ decrypted=(u32 *)crypted;
+ ssh_say(3,"size decrypted : %lx\n",ntohl(*decrypted));
+ return ntohl(*decrypted);
+}
+
+int packet_decrypt(SSH_SESSION *session, void *data,u32 len){
+ struct crypto_struct *crypto=session->current_crypto->in_cipher;
+ char *out=malloc(len);
+ ssh_say(3,"Decrypting %d bytes data\n",len);
+ crypto->set_decrypt_key(crypto,session->current_crypto->decryptkey);
+ crypto->cbc_decrypt(crypto,data,out,len,session->current_crypto->decryptIV);
+ memcpy(data,out,len);
+ memset(out,0,len);
+ free(out);
+ return 0;
+}
+
+char * packet_encrypt(SSH_SESSION *session,void *data,u32 len){
+ struct crypto_struct *crypto;
+ HMAC_CTX *ctx;
+ char *out;
+ int finallen;
+ u32 seq=ntohl(session->send_seq);
+ if(!session->current_crypto)
+ return NULL; /* nothing to do here */
+ crypto= session->current_crypto->out_cipher;
+ ssh_say(3,"seq num = %d, len = %d\n",session->send_seq,len);
+ crypto->set_encrypt_key(crypto,session->current_crypto->encryptkey);
+ out=malloc(len);
+ if(session->version==2){
+ ctx=hmac_init(session->current_crypto->encryptMAC,20,HMAC_SHA1);
+ hmac_update(ctx,(unsigned char *)&seq,sizeof(u32));
+ 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
+ }
+ crypto->cbc_encrypt(crypto,data,out,len,session->current_crypto->encryptIV);
+ memcpy(data,out,len);
+ memset(out,0,len);
+ free(out);
+ if(session->version==2)
+ return session->current_crypto->hmacbuf;
+ else
+ return NULL;
+}
+
+int packet_hmac_verify(SSH_SESSION *session,BUFFER *buffer,char *mac){
+ HMAC_CTX *ctx;
+ unsigned char hmacbuf[EVP_MAX_MD_SIZE];
+ int len;
+ u32 seq=htonl(session->recv_seq);
+ ctx=hmac_init(session->current_crypto->decryptMAC,20,HMAC_SHA1);
+ hmac_update(ctx,(unsigned char *)&seq,sizeof(u32));
+ hmac_update(ctx,buffer_get(buffer),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(u32));
+#endif
+ return memcmp(mac,hmacbuf,len);
+}