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libssh/libssh/auth1.c
2009-09-23 23:51:04 +02:00

260 строки
7.4 KiB
C

/*
* auth1.c - authentication with SSH-1 protocol
*
* This file is part of the SSH Library
*
* Copyright (c) 2005-2008 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 <string.h>
#include <stdlib.h>
#include "libssh/priv.h"
#include "libssh/ssh1.h"
#include "libssh/buffer.h"
#include "libssh/packet.h"
#include "libssh/session.h"
#include "libssh/string.h"
#ifdef WITH_SSH1
static int wait_auth1_status(ssh_session session) {
/* wait for a packet */
if (packet_read(session) != SSH_OK) {
return SSH_AUTH_ERROR;
}
if(packet_translate(session) != SSH_OK) {
return SSH_AUTH_ERROR;
}
switch(session->in_packet.type) {
case SSH_SMSG_SUCCESS:
return SSH_AUTH_SUCCESS;
case SSH_SMSG_FAILURE:
return SSH_AUTH_DENIED;
}
ssh_set_error(session, SSH_FATAL, "Was waiting for a SUCCESS or "
"FAILURE, got %d", session->in_packet.type);
return SSH_AUTH_ERROR;
}
static int send_username(ssh_session session, const char *username) {
ssh_string user = NULL;
/* returns SSH_AUTH_SUCCESS or SSH_AUTH_DENIED */
if(session->auth_service_asked) {
return session->auth_service_asked;
}
if (!username) {
if(!(username = session->options->username)) {
if (ssh_options_set(session->options, SSH_OPTIONS_USER, NULL) < 0) {
return session->auth_service_asked = SSH_AUTH_ERROR;
} else {
username = session->options->username;
}
}
}
user = string_from_char(username);
if (user == NULL) {
return SSH_AUTH_ERROR;
}
if (buffer_add_u8(session->out_buffer, SSH_CMSG_USER) < 0) {
string_free(user);
return SSH_AUTH_ERROR;
}
if (buffer_add_ssh_string(session->out_buffer, user) < 0) {
string_free(user);
return SSH_AUTH_ERROR;
}
string_free(user);
if (packet_send(session) != SSH_OK) {
return SSH_AUTH_ERROR;
}
session->auth_service_asked = wait_auth1_status(session);
return session->auth_service_asked;
}
/* use the "none" authentication question */
int ssh_userauth1_none(ssh_session session, const char *username){
return send_username(session, username);
}
/*
int ssh_userauth_offer_pubkey(ssh_session session, char *username,int type, ssh_string publickey){
ssh_string user;
ssh_string service;
ssh_string method;
ssh_string algo;
int err=SSH_AUTH_ERROR;
if(!username)
if(!(username=session->options->username)){
if(options_default_username(session->options))
return SSH_AUTH_ERROR;
else
username=session->options->username;
}
if(ask_userauth(session))
return SSH_AUTH_ERROR;
user=string_from_char(username);
service=string_from_char("ssh-connection");
method=string_from_char("publickey");
algo=string_from_char(ssh_type_to_char(type));
packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_USERAUTH_REQUEST);
buffer_add_ssh_string(session->out_buffer,user);
buffer_add_ssh_string(session->out_buffer,service);
buffer_add_ssh_string(session->out_buffer,method);
buffer_add_u8(session->out_buffer,0);
buffer_add_ssh_string(session->out_buffer,algo);
buffer_add_ssh_string(session->out_buffer,publickey);
packet_send(session);
err=wait_auth_status(session,0);
free(user);
free(method);
free(service);
free(algo);
return err;
}
*/
/** \internal
* \todo implement ssh1 public key
*/
int ssh_userauth1_offer_pubkey(ssh_session session, const char *username,
int type, ssh_string pubkey) {
(void) session;
(void) username;
(void) type;
(void) pubkey;
return SSH_AUTH_DENIED;
}
/*
int ssh_userauth_pubkey(ssh_session session, char *username, ssh_string publickey, ssh_private_key privatekey){
ssh_string user;
ssh_string service;
ssh_string method;
ssh_string algo;
ssh_string sign;
int err=SSH_AUTH_ERROR;
if(!username)
if(!(username=session->options->username)){
if(options_default_username(session->options))
return err;
else
username=session->options->username;
}
if(ask_userauth(session))
return err;
user=string_from_char(username);
service=string_from_char("ssh-connection");
method=string_from_char("publickey");
algo=string_from_char(ssh_type_to_char(privatekey->type));
*/ /* we said previously the public key was accepted */
/* packet_clear_out(session);
buffer_add_u8(session->out_buffer,SSH2_MSG_USERAUTH_REQUEST);
buffer_add_ssh_string(session->out_buffer,user);
buffer_add_ssh_string(session->out_buffer,service);
buffer_add_ssh_string(session->out_buffer,method);
buffer_add_u8(session->out_buffer,1);
buffer_add_ssh_string(session->out_buffer,algo);
buffer_add_ssh_string(session->out_buffer,publickey);
sign=ssh_do_sign(session,session->out_buffer,privatekey);
if(sign){
buffer_add_ssh_string(session->out_buffer,sign);
free(sign);
packet_send(session);
err=wait_auth_status(session,0);
}
free(user);
free(service);
free(method);
free(algo);
return err;
}
*/
int ssh_userauth1_password(ssh_session session, const char *username,
const char *password) {
ssh_string pwd = NULL;
int rc;
rc = send_username(session, username);
if (rc != SSH_AUTH_DENIED) {
return rc;
}
/* we trick a bit here. A known flaw in SSH1 protocol is that it's
* easy to guess password sizes.
* not that sure ...
*/
/* XXX fix me here ! */
/* cisco IOS doesn't like when a password is followed by zeroes and random pad. */
if(1 || strlen(password) >= 128) {
/* not risky to disclose the size of such a big password .. */
pwd = string_from_char(password);
if (pwd == NULL) {
return SSH_AUTH_ERROR;
}
} else {
/* fill the password string from random things. the strcpy
* ensure there is at least a nul byte after the password.
* most implementation won't see the garbage at end.
* why garbage ? because nul bytes will be compressed by
* gzip and disclose password len.
*/
pwd = string_new(128);
if (pwd == NULL) {
return SSH_AUTH_ERROR;
}
ssh_get_random( pwd->string, 128, 0);
strcpy((char *) pwd->string, password);
}
if (buffer_add_u8(session->out_buffer, SSH_CMSG_AUTH_PASSWORD) < 0) {
string_burn(pwd);
string_free(pwd);
return SSH_AUTH_ERROR;
}
if (buffer_add_ssh_string(session->out_buffer, pwd) < 0) {
string_burn(pwd);
string_free(pwd);
return SSH_AUTH_ERROR;
}
string_burn(pwd);
string_free(pwd);
if (packet_send(session) != SSH_OK) {
return SSH_AUTH_ERROR;
}
return wait_auth1_status(session);
}
#endif /* WITH_SSH1 */
/* vim: set ts=2 sw=2 et cindent: */