ssh-1 small modulus server keys patch

acl bases in mercurius


git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@37 7dcaeef0-15fb-0310-b436-a5af3365683c

libssh/kex.c

@@ -300,8 +300,19 @@ static void build_session_id1(SSH_SESSION *session, STRING *servern,
 #endif
 }
 
+/* returns 1 if the modulus of k1 is < than the one of k2 */
+static int modulus_smaller(PUBLIC_KEY *k1, PUBLIC_KEY *k2){
+    RSA *r1=k1->rsa_pub;
+    RSA *r2=k2->rsa_pub;
+    if(BN_cmp(r1->n,r2->n)<0)
+        return 1;
+    else
+        return 0;
+}
+
+#define ABS(A) ( (A)<0 ? -(A):(A) )
 STRING *encrypt_session_key(SSH_SESSION *session, PUBLIC_KEY *svrkey,
-        PUBLIC_KEY *hostkey){
+        PUBLIC_KEY *hostkey,int slen, int hlen ){
     char buffer[32];
     int i;
     STRING *data1,*data2;
@@ -319,9 +330,19 @@ STRING *encrypt_session_key(SSH_SESSION *session, PUBLIC_KEY *svrkey,
         buffer[i]^=session->next_crypto->session_id[i];
     data1=string_new(32);
     string_fill(data1,buffer,32);
-    data2=ssh_encrypt_rsa1(session,data1,svrkey);
-    free(data1);
-    data1=ssh_encrypt_rsa1(session,data2,hostkey);
+    if(ABS(hlen-slen)<128){
+        ssh_say(1,"Difference between server modulus and host modulus is only %d. It's illegal and may not work\n",
+                ABS(hlen-slen));
+    }
+    if(modulus_smaller(svrkey,hostkey)){
+        data2=ssh_encrypt_rsa1(session,data1,svrkey);
+        free(data1);
+        data1=ssh_encrypt_rsa1(session,data2,hostkey);
+    } else {
+        data2=ssh_encrypt_rsa1(session,data1,hostkey);
+        free(data1);
+        data1=ssh_encrypt_rsa1(session,data2,svrkey);
+    }
     return data1;
 }
 
@@ -417,7 +438,7 @@ int ssh_get_kex1(SSH_SESSION *session){
     buffer_add_u8(session->out_buffer,SSH_CIPHER_3DES);
     buffer_add_data(session->out_buffer,session->server_kex.cookie,8);
     
-    enc_session=encrypt_session_key(session,svr,host);
+    enc_session=encrypt_session_key(session,svr,host,server_bits, host_bits);
     bits=string_len(enc_session)*8 - 7;
     ssh_say(2,"%d bits,%d bytes encrypted session\n",bits,string_len(enc_session));
     bits=htons(bits);
@@ -435,7 +456,9 @@ int ssh_get_kex1(SSH_SESSION *session){
     session->current_crypto=session->next_crypto;
     session->next_crypto=NULL;
     if(packet_wait(session,SSH_SMSG_SUCCESS,1)){
-        ssh_set_error(session,SSH_FATAL,"Key exchange failed : %s\n",ssh_get_error(session));
+        char buffer[1024];
+        snprintf(buffer,sizeof(buffer),"Key exchange failed : %s",ssh_get_error(session));
+        ssh_set_error(session,SSH_FATAL,"%s",buffer);
         return -1;
     }
     ssh_say(1,"received SSH_SMSG_SUCCESS\n");

sftp_server/Makefile

@@ -1,4 +1,4 @@
-OBJECTS= main.o config.o list.o protocol.o userauth.o \
+OBJECTS= main.o config.o list.o protocol.o userauth.o file.o acl.o \
 		libconfig/libconfig.a ../libssh/libssh.a
 SHELL = /bin/sh
 

sftp_server/Makefile.in

@@ -1,4 +1,4 @@
-OBJECTS= main.o config.o list.o protocol.o userauth.o \
+OBJECTS= main.o config.o list.o protocol.o userauth.o file.o acl.o \
 		libconfig/libconfig.a ../libssh/libssh.a
 SHELL = /bin/sh
 VPATH = @srcdir@

sftp_server/acl.c

@@ -0,0 +1,31 @@
+/* Access control lists*/
+/*
+Copyright 2005 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 "server.h"
+
+int acl_open(char *file, int mode);
+int acl_opendir(char *dir);
+int acl_stat(char *file);
+int acl_rm(char *file);
+int acl_rmdir(char *dir);
+int acl_mv(char *from, char *to);
+int acl_mkdir(char *dir);
+int acl_symlink(char *from, char *to);
+int acl_setstat(char *file);

sftp_server/server.h

@@ -44,3 +44,46 @@ struct dir {
     list *Write;
 };
 
+/* acl_* functions returns this : */
+/* 1 : operation allowed */
+/* 0 : operation denied */
+int acl_open(char *file, int mode);
+int acl_opendir(char *dir);
+int acl_stat(char *file);
+int acl_rm(char *file);
+int acl_rmdir(char *dir);
+int acl_mv(char *from, char *to);
+int acl_mkdir(char *dir);
+int acl_symlink(char *from, char *to);
+int acl_setstat(char *file);
+
+/* still experimental */
+
+#define BLOCKLEN 65536
+
+/* here is how it works : */
+/* the buffer is BLOCKLEN long. */
+/* Bytes is the number of valid bytes into the buffer. these valid bytes */
+/* begin at &buffer[0]  */
+/* buffer+start is mapped at offset. */
+/* thus, there are (bytes-start) bytes ready to be read. */
+
+struct file {
+    int fd;
+    u64 offset;
+    unsigned char buffer[BLOCKLEN];
+    int bytes;
+    int start; // number of the first byte pointed by offset
+    int mode;
+    int eof;
+    int delayed_write; /* there are data into the buffer to be read */
+    int write_end; /* end of data, relative to buffer[0] */
+    int write_start; /* begining of data */
+};
+
+
+struct file *file_open(char *filename, int mode);
+int file_sync(struct file *file);
+int file_close(struct file *file);
+
+