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246bec30bc
tmate/libssh/src/server.c
Nicolas Viennot 246bec30bc Updated libssh
2013-08-16 13:32:26 -04:00

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/*
* server.c - functions for creating a SSH server
*
* This file is part of the SSH Library
*
* Copyright (c) 2004-2005 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 <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#ifdef _WIN32
# include <winsock2.h>
# include <ws2tcpip.h>
/*
* <wspiapi.h> is necessary for getaddrinfo before Windows XP, but it isn't
* available on some platforms like MinGW.
*/
# ifdef HAVE_WSPIAPI_H
# include <wspiapi.h>
# endif
#else
# include <netinet/in.h>
#endif
#include "libssh/priv.h"
#include "libssh/libssh.h"
#include "libssh/server.h"
#include "libssh/ssh2.h"
#include "libssh/buffer.h"
#include "libssh/packet.h"
#include "libssh/socket.h"
#include "libssh/session.h"
#include "libssh/kex.h"
#include "libssh/misc.h"
#include "libssh/pki.h"
#include "libssh/dh.h"
#include "libssh/messages.h"
#include "libssh/options.h"
#define set_status(session, status) do {\
if (session->common.callbacks && session->common.callbacks->connect_status_function) \
session->common.callbacks->connect_status_function(session->common.callbacks->userdata, status); \
} while (0)
static int dh_handshake_server(ssh_session session);
/**
* @addtogroup libssh_server
*
* @{
*/
/** @internal
* This functions sets the Key Exchange protocols to be accepted
* by the server. They depend on
* -What the user asked (via options)
* -What is available (keys)
* It should then accept the intersection of what the user asked
* and what is available, and return an error if nothing matches
*/
static int server_set_kex(ssh_session session) {
struct ssh_kex_struct *server = &session->next_crypto->server_kex;
int i, j, rc;
const char *wanted;
char hostkeys[64] = {0};
enum ssh_keytypes_e keytype;
size_t len;
ZERO_STRUCTP(server);
ssh_get_random(server->cookie, 16, 0);
#ifdef HAVE_ECC
if (session->srv.ecdsa_key != NULL) {
snprintf(hostkeys, sizeof(hostkeys),
"%s", session->srv.ecdsa_key->type_c);
}
#endif
if (session->srv.dsa_key != NULL) {
len = strlen(hostkeys);
keytype = ssh_key_type(session->srv.dsa_key);
snprintf(hostkeys + len, sizeof(hostkeys) - len,
",%s", ssh_key_type_to_char(keytype));
}
if (session->srv.rsa_key != NULL) {
len = strlen(hostkeys);
keytype = ssh_key_type(session->srv.rsa_key);
snprintf(hostkeys + len, sizeof(hostkeys) - len,
",%s", ssh_key_type_to_char(keytype));
}
if (strlen(hostkeys) == 0) {
return -1;
}
rc = ssh_options_set_algo(session,
SSH_HOSTKEYS,
hostkeys[0] == ',' ? hostkeys + 1 : hostkeys);
if (rc < 0) {
return -1;
}
for (i = 0; i < 10; i++) {
if ((wanted = session->opts.wanted_methods[i]) == NULL) {
wanted = ssh_kex_get_supported_method(i);
}
server->methods[i] = strdup(wanted);
if (server->methods[i] == NULL) {
for (j = 0; j < i; j++) {
SAFE_FREE(server->methods[j]);
}
return -1;
}
}
return 0;
}
/** @internal
* @brief parse an incoming SSH_MSG_KEXDH_INIT packet and complete
* key exchange
**/
static int ssh_server_kexdh_init(ssh_session session, ssh_buffer packet){
ssh_string e;
e = buffer_get_ssh_string(packet);
if (e == NULL) {
ssh_set_error(session, SSH_FATAL, "No e number in client request");
return -1;
}
if (dh_import_e(session, e) < 0) {
ssh_set_error(session, SSH_FATAL, "Cannot import e number");
session->session_state=SSH_SESSION_STATE_ERROR;
} else {
session->dh_handshake_state=DH_STATE_INIT_SENT;
dh_handshake_server(session);
}
ssh_string_free(e);
return SSH_OK;
}
SSH_PACKET_CALLBACK(ssh_packet_kexdh_init){
int rc;
(void)type;
(void)user;
SSH_LOG(SSH_LOG_PACKET,"Received SSH_MSG_KEXDH_INIT");
if(session->dh_handshake_state != DH_STATE_INIT){
SSH_LOG(SSH_LOG_RARE,"Invalid state for SSH_MSG_KEXDH_INIT");
goto error;
}
switch(session->next_crypto->kex_type){
case SSH_KEX_DH_GROUP1_SHA1:
case SSH_KEX_DH_GROUP14_SHA1:
rc=ssh_server_kexdh_init(session, packet);
break;
#ifdef HAVE_ECDH
case SSH_KEX_ECDH_SHA2_NISTP256:
rc = ssh_server_ecdh_init(session, packet);
break;
#endif
default:
ssh_set_error(session,SSH_FATAL,"Wrong kex type in ssh_packet_kexdh_init");
rc = SSH_ERROR;
}
if (rc == SSH_ERROR)
session->session_state = SSH_SESSION_STATE_ERROR;
error:
return SSH_PACKET_USED;
}
int ssh_get_key_params(ssh_session session, ssh_key *privkey){
ssh_key pubkey;
ssh_string pubkey_blob;
int rc;
switch(session->srv.hostkey) {
case SSH_KEYTYPE_DSS:
*privkey = session->srv.dsa_key;
break;
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
*privkey = session->srv.rsa_key;
break;
case SSH_KEYTYPE_ECDSA:
*privkey = session->srv.ecdsa_key;
break;
case SSH_KEYTYPE_UNKNOWN:
*privkey = NULL;
}
rc = ssh_pki_export_privkey_to_pubkey(*privkey, &pubkey);
if (rc < 0) {
ssh_set_error(session, SSH_FATAL,
"Could not get the public key from the private key");
return -1;
}
rc = ssh_pki_export_pubkey_blob(pubkey, &pubkey_blob);
ssh_key_free(pubkey);
if (rc < 0) {
ssh_set_error_oom(session);
return -1;
}
dh_import_pubkey(session, pubkey_blob);
return SSH_OK;
}
static int dh_handshake_server(ssh_session session) {
ssh_key privkey;
//ssh_string pubkey_blob = NULL;
ssh_string sig_blob;
ssh_string f;
if (dh_generate_y(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not create y number");
return -1;
}
if (dh_generate_f(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not create f number");
return -1;
}
f = dh_get_f(session);
if (f == NULL) {
ssh_set_error(session, SSH_FATAL, "Could not get the f number");
return -1;
}
if (ssh_get_key_params(session,&privkey) != SSH_OK){
ssh_string_free(f);
return -1;
}
if (dh_build_k(session) < 0) {
ssh_set_error(session, SSH_FATAL, "Could not import the public key");
ssh_string_free(f);
return -1;
}
if (make_sessionid(session) != SSH_OK) {
ssh_set_error(session, SSH_FATAL, "Could not create a session id");
ssh_string_free(f);
return -1;
}
sig_blob = ssh_srv_pki_do_sign_sessionid(session, privkey);
if (sig_blob == NULL) {
ssh_set_error(session, SSH_FATAL, "Could not sign the session id");
ssh_string_free(f);
return -1;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_KEXDH_REPLY) < 0 ||
buffer_add_ssh_string(session->out_buffer,
session->next_crypto->server_pubkey) < 0 ||
buffer_add_ssh_string(session->out_buffer, f) < 0 ||
buffer_add_ssh_string(session->out_buffer, sig_blob) < 0) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
buffer_reinit(session->out_buffer);
ssh_string_free(f);
ssh_string_free(sig_blob);
return -1;
}
ssh_string_free(f);
ssh_string_free(sig_blob);
if (packet_send(session) == SSH_ERROR) {
return -1;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_NEWKEYS) < 0) {
buffer_reinit(session->out_buffer);
return -1;
}
if (packet_send(session) == SSH_ERROR) {
return -1;
}
SSH_LOG(SSH_LOG_PACKET, "SSH_MSG_NEWKEYS sent");
session->dh_handshake_state=DH_STATE_NEWKEYS_SENT;
return 0;
}
/**
* @internal
*
* @brief A function to be called each time a step has been done in the
* connection.
*/
static void ssh_server_connection_callback(ssh_session session){
int ssh1,ssh2;
switch(session->session_state){
case SSH_SESSION_STATE_NONE:
case SSH_SESSION_STATE_CONNECTING:
case SSH_SESSION_STATE_SOCKET_CONNECTED:
break;
case SSH_SESSION_STATE_BANNER_RECEIVED:
if (session->clientbanner == NULL) {
goto error;
}
set_status(session, 0.4f);
SSH_LOG(SSH_LOG_RARE,
"SSH client banner: %s", session->clientbanner);
/* Here we analyze the different protocols the server allows. */
if (ssh_analyze_banner(session, 1, &ssh1, &ssh2) < 0) {
goto error;
}
/* Here we decide which version of the protocol to use. */
if (ssh2 && session->opts.ssh2) {
session->version = 2;
} else if (ssh1 && session->opts.ssh1) {
session->version = 1;
} else if (ssh1 && !session->opts.ssh1) {
#ifdef WITH_SSH1
ssh_set_error(session, SSH_FATAL,
"SSH-1 protocol not available (configure session to allow SSH-1)");
goto error;
#else
ssh_set_error(session, SSH_FATAL,
"SSH-1 protocol not available (libssh compiled without SSH-1 support)");
goto error;
#endif
} else {
ssh_set_error(session, SSH_FATAL,
"No version of SSH protocol usable (banner: %s)",
session->clientbanner);
goto error;
}
/* from now, the packet layer is handling incoming packets */
if(session->version==2)
session->socket_callbacks.data=ssh_packet_socket_callback;
#ifdef WITH_SSH1
else
session->socket_callbacks.data=ssh_packet_socket_callback1;
#endif
ssh_packet_set_default_callbacks(session);
set_status(session, 0.5f);
session->session_state=SSH_SESSION_STATE_INITIAL_KEX;
if (ssh_send_kex(session, 1) < 0) {
goto error;
}
break;
case SSH_SESSION_STATE_INITIAL_KEX:
/* TODO: This state should disappear in favor of get_key handle */
#ifdef WITH_SSH1
if(session->version==1){
if (ssh_get_kex1(session) < 0)
goto error;
set_status(session,0.6f);
session->connected = 1;
break;
}
#endif
break;
case SSH_SESSION_STATE_KEXINIT_RECEIVED:
set_status(session,0.6f);
if(session->next_crypto->server_kex.methods[0]==NULL){
if(server_set_kex(session) == SSH_ERROR)
goto error;
/* We are in a rekeying, so we need to send the server kex */
if(ssh_send_kex(session, 1) < 0)
goto error;
}
ssh_list_kex(&session->next_crypto->client_kex); // log client kex
if (ssh_kex_select_methods(session) < 0) {
goto error;
}
if (crypt_set_algorithms_server(session) == SSH_ERROR)
goto error;
set_status(session,0.8f);
session->session_state=SSH_SESSION_STATE_DH;
break;
case SSH_SESSION_STATE_DH:
if(session->dh_handshake_state==DH_STATE_FINISHED){
if (generate_session_keys(session) < 0) {
goto error;
}
/*
* Once we got SSH2_MSG_NEWKEYS we can switch next_crypto and
* current_crypto
*/
if (session->current_crypto) {
crypto_free(session->current_crypto);
}
/* FIXME TODO later, include a function to change keys */
session->current_crypto = session->next_crypto;
session->next_crypto = crypto_new();
if (session->next_crypto == NULL) {
goto error;
}
session->next_crypto->session_id = malloc(session->current_crypto->digest_len);
if (session->next_crypto->session_id == NULL) {
ssh_set_error_oom(session);
goto error;
}
memcpy(session->next_crypto->session_id, session->current_crypto->session_id,
session->current_crypto->digest_len);
set_status(session,1.0f);
session->connected = 1;
session->session_state=SSH_SESSION_STATE_AUTHENTICATING;
if (session->flags & SSH_SESSION_FLAG_AUTHENTICATED)
session->session_state = SSH_SESSION_STATE_AUTHENTICATED;
}
break;
case SSH_SESSION_STATE_AUTHENTICATING:
break;
case SSH_SESSION_STATE_ERROR:
goto error;
default:
ssh_set_error(session,SSH_FATAL,"Invalid state %d",session->session_state);
}
return;
error:
ssh_socket_close(session->socket);
session->alive = 0;
session->session_state=SSH_SESSION_STATE_ERROR;
}
/**
* @internal
*
* @brief Gets the banner from socket and saves it in session.
* Updates the session state
*
* @param data pointer to the beginning of header
* @param len size of the banner
* @param user is a pointer to session
* @returns Number of bytes processed, or zero if the banner is not complete.
*/
static int callback_receive_banner(const void *data, size_t len, void *user) {
char *buffer = (char *) data;
ssh_session session = (ssh_session) user;
char *str = NULL;
size_t i;
int ret=0;
for (i = 0; i < len; i++) {
#ifdef WITH_PCAP
if(session->pcap_ctx && buffer[i] == '\n') {
ssh_pcap_context_write(session->pcap_ctx,
SSH_PCAP_DIR_IN,
buffer,
i + 1,
i + 1);
}
#endif
if (buffer[i] == '\r') {
buffer[i]='\0';
}
if (buffer[i] == '\n') {
buffer[i]='\0';
str = strdup(buffer);
/* number of bytes read */
ret = i + 1;
session->clientbanner = str;
session->session_state = SSH_SESSION_STATE_BANNER_RECEIVED;
SSH_LOG(SSH_LOG_PACKET, "Received banner: %s", str);
session->ssh_connection_callback(session);
return ret;
}
if(i > 127) {
/* Too big banner */
session->session_state = SSH_SESSION_STATE_ERROR;
ssh_set_error(session, SSH_FATAL, "Receiving banner: too large banner");
return 0;
}
}
return ret;
}
/* returns 0 until the key exchange is not finished */
static int ssh_server_kex_termination(void *s){
ssh_session session = s;
if (session->session_state != SSH_SESSION_STATE_ERROR &&
session->session_state != SSH_SESSION_STATE_AUTHENTICATING &&
session->session_state != SSH_SESSION_STATE_DISCONNECTED)
return 0;
else
return 1;
}
/** Set the acceptable authentication methods to be sent to
* client.
* @param[in] session the SSH server session
* @param[in] auth_methods Bitfield of authentication methods
* to be accepted, e.g. SSH_AUTH_METHOD_PUBLICKEY
*/
void ssh_set_auth_methods(ssh_session session, int auth_methods){
/* accept only methods in range */
session->auth_methods = auth_methods & 0x3f;
}
/* Do the banner and key exchange */
int ssh_handle_key_exchange(ssh_session session) {
int rc;
if (session->session_state != SSH_SESSION_STATE_NONE)
goto pending;
rc = ssh_send_banner(session, 1);
if (rc < 0) {
return SSH_ERROR;
}
session->alive = 1;
session->ssh_connection_callback = ssh_server_connection_callback;
session->session_state = SSH_SESSION_STATE_SOCKET_CONNECTED;
ssh_socket_set_callbacks(session->socket,&session->socket_callbacks);
session->socket_callbacks.data=callback_receive_banner;
session->socket_callbacks.exception=ssh_socket_exception_callback;
session->socket_callbacks.userdata=session;
rc = server_set_kex(session);
if (rc < 0) {
return SSH_ERROR;
}
pending:
rc = ssh_handle_packets_termination(session, SSH_TIMEOUT_USER,
ssh_server_kex_termination,session);
SSH_LOG(SSH_LOG_PACKET, "ssh_handle_key_exchange: current state : %d",
session->session_state);
if (rc != SSH_OK)
return rc;
if (session->session_state == SSH_SESSION_STATE_ERROR ||
session->session_state == SSH_SESSION_STATE_DISCONNECTED) {
return SSH_ERROR;
}
return SSH_OK;
}
/* messages */
/** @internal
* replies to an SSH_AUTH packet with a default (denied) response.
*/
int ssh_auth_reply_default(ssh_session session,int partial) {
char methods_c[128] = {0};
ssh_string methods = NULL;
int rc = SSH_ERROR;
if (buffer_add_u8(session->out_buffer, SSH2_MSG_USERAUTH_FAILURE) < 0) {
return rc;
}
if (session->auth_methods == 0) {
session->auth_methods = SSH_AUTH_METHOD_PUBLICKEY | SSH_AUTH_METHOD_PASSWORD;
}
if (session->auth_methods & SSH_AUTH_METHOD_PUBLICKEY) {
strncat(methods_c, "publickey,",
sizeof(methods_c) - strlen(methods_c) - 1);
}
if (session->auth_methods & SSH_AUTH_METHOD_GSSAPI_MIC){
strncat(methods_c,"gssapi-with-mic,",
sizeof(methods_c) - strlen(methods_c) - 1);
}
if (session->auth_methods & SSH_AUTH_METHOD_INTERACTIVE) {
strncat(methods_c, "keyboard-interactive,",
sizeof(methods_c) - strlen(methods_c) - 1);
}
if (session->auth_methods & SSH_AUTH_METHOD_PASSWORD) {
strncat(methods_c, "password,",
sizeof(methods_c) - strlen(methods_c) - 1);
}
if (session->auth_methods & SSH_AUTH_METHOD_HOSTBASED) {
strncat(methods_c, "hostbased,",
sizeof(methods_c) - strlen(methods_c) - 1);
}
if (methods_c[0] == '\0' || methods_c[strlen(methods_c)-1] != ',') {
return SSH_ERROR;
}
/* Strip the comma. */
methods_c[strlen(methods_c) - 1] = '\0'; // strip the comma. We are sure there is at
SSH_LOG(SSH_LOG_PACKET,
"Sending a auth failure. methods that can continue: %s", methods_c);
methods = ssh_string_from_char(methods_c);
if (methods == NULL) {
goto error;
}
if (buffer_add_ssh_string(session->out_buffer, methods) < 0) {
goto error;
}
if (partial) {
if (buffer_add_u8(session->out_buffer, 1) < 0) {
goto error;
}
} else {
if (buffer_add_u8(session->out_buffer, 0) < 0) {
goto error;
}
}
rc = packet_send(session);
error:
ssh_string_free(methods);
return rc;
}
static int ssh_message_channel_request_open_reply_default(ssh_message msg) {
SSH_LOG(SSH_LOG_FUNCTIONS, "Refusing a channel");
if (buffer_add_u8(msg->session->out_buffer
, SSH2_MSG_CHANNEL_OPEN_FAILURE) < 0) {
goto error;
}
if (buffer_add_u32(msg->session->out_buffer,
htonl(msg->channel_request_open.sender)) < 0) {
goto error;
}
if (buffer_add_u32(msg->session->out_buffer,
htonl(SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED)) < 0) {
goto error;
}
/* reason is an empty string */
if (buffer_add_u32(msg->session->out_buffer, 0) < 0) {
goto error;
}
/* language too */
if (buffer_add_u32(msg->session->out_buffer, 0) < 0) {
goto error;
}
return packet_send(msg->session);
error:
return SSH_ERROR;
}
static int ssh_message_channel_request_reply_default(ssh_message msg) {
uint32_t channel;
if (msg->channel_request.want_reply) {
channel = msg->channel_request.channel->remote_channel;
SSH_LOG(SSH_LOG_PACKET,
"Sending a default channel_request denied to channel %d", channel);
if (buffer_add_u8(msg->session->out_buffer, SSH2_MSG_CHANNEL_FAILURE) < 0) {
return SSH_ERROR;
}
if (buffer_add_u32(msg->session->out_buffer, htonl(channel)) < 0) {
return SSH_ERROR;
}
return packet_send(msg->session);
}
SSH_LOG(SSH_LOG_PACKET,
"The client doesn't want to know the request failed!");
return SSH_OK;
}
static int ssh_message_service_request_reply_default(ssh_message msg) {
/* The only return code accepted by specifications are success or disconnect */
return ssh_message_service_reply_success(msg);
}
int ssh_message_service_reply_success(ssh_message msg) {
struct ssh_string_struct *service;
ssh_session session;
if (msg == NULL) {
return SSH_ERROR;
}
session = msg->session;
SSH_LOG(SSH_LOG_PACKET,
"Sending a SERVICE_ACCEPT for service %s", msg->service_request.service);
if (buffer_add_u8(session->out_buffer, SSH2_MSG_SERVICE_ACCEPT) < 0) {
return -1;
}
service=ssh_string_from_char(msg->service_request.service);
if (service == NULL) {
return -1;
}
if (buffer_add_ssh_string(session->out_buffer, service) < 0) {
ssh_string_free(service);
return -1;
}
ssh_string_free(service);
return packet_send(msg->session);
}
int ssh_message_global_request_reply_success(ssh_message msg, uint16_t bound_port) {
SSH_LOG(SSH_LOG_FUNCTIONS, "Accepting a global request");
if (msg->global_request.want_reply) {
if (buffer_add_u8(msg->session->out_buffer
, SSH2_MSG_REQUEST_SUCCESS) < 0) {
goto error;
}
if(msg->global_request.type == SSH_GLOBAL_REQUEST_TCPIP_FORWARD
&& msg->global_request.bind_port == 0) {
if (buffer_add_u32(msg->session->out_buffer, htonl(bound_port)) < 0) {
goto error;
}
}
return packet_send(msg->session);
}
if(msg->global_request.type == SSH_GLOBAL_REQUEST_TCPIP_FORWARD
&& msg->global_request.bind_port == 0) {
SSH_LOG(SSH_LOG_PACKET,
"The client doesn't want to know the remote port!");
}
return SSH_OK;
error:
return SSH_ERROR;
}
static int ssh_message_global_request_reply_default(ssh_message msg) {
SSH_LOG(SSH_LOG_FUNCTIONS, "Refusing a global request");
if (msg->global_request.want_reply) {
if (buffer_add_u8(msg->session->out_buffer
, SSH2_MSG_REQUEST_FAILURE) < 0) {
goto error;
}
return packet_send(msg->session);
}
SSH_LOG(SSH_LOG_PACKET,
"The client doesn't want to know the request failed!");
return SSH_OK;
error:
return SSH_ERROR;
}
int ssh_message_reply_default(ssh_message msg) {
if (msg == NULL) {
return -1;
}
switch(msg->type) {
case SSH_REQUEST_AUTH:
return ssh_auth_reply_default(msg->session, 0);
case SSH_REQUEST_CHANNEL_OPEN:
return ssh_message_channel_request_open_reply_default(msg);
case SSH_REQUEST_CHANNEL:
return ssh_message_channel_request_reply_default(msg);
case SSH_REQUEST_SERVICE:
return ssh_message_service_request_reply_default(msg);
case SSH_REQUEST_GLOBAL:
return ssh_message_global_request_reply_default(msg);
default:
SSH_LOG(SSH_LOG_PACKET,
"Don't know what to default reply to %d type",
msg->type);
break;
}
return -1;
}
const char *ssh_message_service_service(ssh_message msg){
if (msg == NULL) {
return NULL;
}
return msg->service_request.service;
}
const char *ssh_message_auth_user(ssh_message msg) {
if (msg == NULL) {
return NULL;
}
return msg->auth_request.username;
}
const char *ssh_message_auth_password(ssh_message msg){
if (msg == NULL) {
return NULL;
}
return msg->auth_request.password;
}
ssh_key ssh_message_auth_pubkey(ssh_message msg) {
if (msg == NULL) {
return NULL;
}
return msg->auth_request.pubkey;
}
/* Get the publickey of an auth request */
ssh_public_key ssh_message_auth_publickey(ssh_message msg){
if (msg == NULL) {
return NULL;
}
return ssh_pki_convert_key_to_publickey(msg->auth_request.pubkey);
}
enum ssh_publickey_state_e ssh_message_auth_publickey_state(ssh_message msg){
if (msg == NULL) {
return -1;
}
return msg->auth_request.signature_state;
}
int ssh_message_auth_kbdint_is_response(ssh_message msg) {
if (msg == NULL) {
return -1;
}
return msg->auth_request.kbdint_response != 0;
}
int ssh_message_auth_set_methods(ssh_message msg, int methods) {
if (msg == NULL || msg->session == NULL) {
return -1;
}
msg->session->auth_methods = methods;
return 0;
}
int ssh_message_auth_interactive_request(ssh_message msg, const char *name,
const char *instruction, unsigned int num_prompts,
const char **prompts, char *echo) {
int r;
unsigned int i = 0;
ssh_string tmp = NULL;
if(name == NULL || instruction == NULL) {
return SSH_ERROR;
}
if(num_prompts > 0 && (prompts == NULL || echo == NULL)) {
return SSH_ERROR;
}
if (buffer_add_u8(msg->session->out_buffer, SSH2_MSG_USERAUTH_INFO_REQUEST) < 0) {
return SSH_ERROR;
}
/* name */
tmp = ssh_string_from_char(name);
if (tmp == NULL) {
return SSH_ERROR;
}
r = buffer_add_ssh_string(msg->session->out_buffer, tmp);
ssh_string_free(tmp);
if (r < 0) {
return SSH_ERROR;
}
/* instruction */
tmp = ssh_string_from_char(instruction);
if (tmp == NULL) {
return SSH_ERROR;
}
r = buffer_add_ssh_string(msg->session->out_buffer, tmp);
ssh_string_free(tmp);
if (r < 0) {
return SSH_ERROR;
}
/* language tag */
tmp = ssh_string_from_char("");
if (tmp == NULL) {
return SSH_ERROR;
}
r = buffer_add_ssh_string(msg->session->out_buffer, tmp);
ssh_string_free(tmp);
if (r < 0) {
return SSH_ERROR;
}
/* num prompts */
if (buffer_add_u32(msg->session->out_buffer, ntohl(num_prompts)) < 0) {
return SSH_ERROR;
}
for(i = 0; i < num_prompts; i++) {
/* prompt[i] */
tmp = ssh_string_from_char(prompts[i]);
if (tmp == NULL) {
return SSH_ERROR;
}
r = buffer_add_ssh_string(msg->session->out_buffer, tmp);
ssh_string_free(tmp);
if (r < 0) {
return SSH_ERROR;
}
/* echo[i] */
if (buffer_add_u8(msg->session->out_buffer, echo[i]) < 0) {
return SSH_ERROR;
}
}
r = packet_send(msg->session);
/* fill in the kbdint structure */
if (msg->session->kbdint == NULL) {
SSH_LOG(SSH_LOG_PROTOCOL, "Warning: Got a "
"keyboard-interactive response but it "
"seems we didn't send the request.");
msg->session->kbdint = ssh_kbdint_new();
if (msg->session->kbdint == NULL) {
ssh_set_error_oom(msg->session);
return SSH_ERROR;
}
} else {
ssh_kbdint_clean(msg->session->kbdint);
}
msg->session->kbdint->name = strdup(name);
if(msg->session->kbdint->name == NULL) {
ssh_set_error_oom(msg->session);
ssh_kbdint_free(msg->session->kbdint);
msg->session->kbdint = NULL;
return SSH_PACKET_USED;
}
msg->session->kbdint->instruction = strdup(instruction);
if(msg->session->kbdint->instruction == NULL) {
ssh_set_error_oom(msg->session);
ssh_kbdint_free(msg->session->kbdint);
msg->session->kbdint = NULL;
return SSH_PACKET_USED;
}
msg->session->kbdint->nprompts = num_prompts;
if(num_prompts > 0) {
msg->session->kbdint->prompts = malloc(num_prompts * sizeof(char *));
if (msg->session->kbdint->prompts == NULL) {
msg->session->kbdint->nprompts = 0;
ssh_set_error_oom(msg->session);
ssh_kbdint_free(msg->session->kbdint);
msg->session->kbdint = NULL;
return SSH_ERROR;
}
msg->session->kbdint->echo = malloc(num_prompts * sizeof(char));
if (msg->session->kbdint->echo == NULL) {
ssh_set_error_oom(msg->session);
ssh_kbdint_free(msg->session->kbdint);
msg->session->kbdint = NULL;
return SSH_ERROR;
}
for (i = 0; i < num_prompts; i++) {
msg->session->kbdint->echo[i] = echo[i];
msg->session->kbdint->prompts[i] = strdup(prompts[i]);
if (msg->session->kbdint->prompts[i] == NULL) {
ssh_set_error_oom(msg->session);
msg->session->kbdint->nprompts = i;
ssh_kbdint_free(msg->session->kbdint);
msg->session->kbdint = NULL;
return SSH_PACKET_USED;
}
}
} else {
msg->session->kbdint->prompts = NULL;
msg->session->kbdint->echo = NULL;
}
return r;
}
int ssh_auth_reply_success(ssh_session session, int partial) {
int r;
if (session == NULL) {
return SSH_ERROR;
}
if (partial) {
return ssh_auth_reply_default(session, partial);
}
session->session_state = SSH_SESSION_STATE_AUTHENTICATED;
session->flags |= SSH_SESSION_FLAG_AUTHENTICATED;
if (buffer_add_u8(session->out_buffer,SSH2_MSG_USERAUTH_SUCCESS) < 0) {
return SSH_ERROR;
}
r = packet_send(session);
if(session->current_crypto && session->current_crypto->delayed_compress_out){
SSH_LOG(SSH_LOG_PROTOCOL,"Enabling delayed compression OUT");
session->current_crypto->do_compress_out=1;
}
if(session->current_crypto && session->current_crypto->delayed_compress_in){
SSH_LOG(SSH_LOG_PROTOCOL,"Enabling delayed compression IN");
session->current_crypto->do_compress_in=1;
}
return r;
}
int ssh_message_auth_reply_success(ssh_message msg, int partial) {
if(msg == NULL)
return SSH_ERROR;
return ssh_auth_reply_success(msg->session, partial);
}
/* Answer OK to a pubkey auth request */
int ssh_message_auth_reply_pk_ok(ssh_message msg, ssh_string algo, ssh_string pubkey) {
if (msg == NULL) {
return SSH_ERROR;
}
if (buffer_add_u8(msg->session->out_buffer, SSH2_MSG_USERAUTH_PK_OK) < 0 ||
buffer_add_ssh_string(msg->session->out_buffer, algo) < 0 ||
buffer_add_ssh_string(msg->session->out_buffer, pubkey) < 0) {
return SSH_ERROR;
}
return packet_send(msg->session);
}
int ssh_message_auth_reply_pk_ok_simple(ssh_message msg) {
ssh_string algo;
ssh_string pubkey_blob = NULL;
int ret;
algo = ssh_string_from_char(msg->auth_request.pubkey->type_c);
if (algo == NULL) {
return SSH_ERROR;
}
ret = ssh_pki_export_pubkey_blob(msg->auth_request.pubkey, &pubkey_blob);
if (ret < 0) {
ssh_string_free(algo);
return SSH_ERROR;
}
ret = ssh_message_auth_reply_pk_ok(msg, algo, pubkey_blob);
ssh_string_free(algo);
ssh_string_free(pubkey_blob);
return ret;
}
const char *ssh_message_channel_request_open_originator(ssh_message msg){
return msg->channel_request_open.originator;
}
int ssh_message_channel_request_open_originator_port(ssh_message msg){
return msg->channel_request_open.originator_port;
}
const char *ssh_message_channel_request_open_destination(ssh_message msg){
return msg->channel_request_open.destination;
}
int ssh_message_channel_request_open_destination_port(ssh_message msg){
return msg->channel_request_open.destination_port;
}
ssh_channel ssh_message_channel_request_channel(ssh_message msg){
return msg->channel_request.channel;
}
const char *ssh_message_channel_request_pty_term(ssh_message msg){
return msg->channel_request.TERM;
}
int ssh_message_channel_request_pty_width(ssh_message msg){
return msg->channel_request.width;
}
int ssh_message_channel_request_pty_height(ssh_message msg){
return msg->channel_request.height;
}
int ssh_message_channel_request_pty_pxwidth(ssh_message msg){
return msg->channel_request.pxwidth;
}
int ssh_message_channel_request_pty_pxheight(ssh_message msg){
return msg->channel_request.pxheight;
}
const char *ssh_message_channel_request_env_name(ssh_message msg){
return msg->channel_request.var_name;
}
const char *ssh_message_channel_request_env_value(ssh_message msg){
return msg->channel_request.var_value;
}
const char *ssh_message_channel_request_command(ssh_message msg){
return msg->channel_request.command;
}
const char *ssh_message_channel_request_subsystem(ssh_message msg){
return msg->channel_request.subsystem;
}
int ssh_message_channel_request_x11_single_connection(ssh_message msg){
return msg->channel_request.x11_single_connection ? 1 : 0;
}
const char *ssh_message_channel_request_x11_auth_protocol(ssh_message msg){
return msg->channel_request.x11_auth_protocol;
}
const char *ssh_message_channel_request_x11_auth_cookie(ssh_message msg){
return msg->channel_request.x11_auth_cookie;
}
int ssh_message_channel_request_x11_screen_number(ssh_message msg){
return msg->channel_request.x11_screen_number;
}
const char *ssh_message_global_request_address(ssh_message msg){
return msg->global_request.bind_address;
}
int ssh_message_global_request_port(ssh_message msg){
return msg->global_request.bind_port;
}
/** @brief defines the ssh_message callback
* @param session the current ssh session
* @param[in] ssh_bind_message_callback a function pointer to a callback taking the
* current ssh session and received message as parameters. the function returns
* 0 if the message has been parsed and treated successfully, 1 otherwise (libssh
* must take care of the response).
* @param[in] data void pointer to be passed to callback functions
*/
void ssh_set_message_callback(ssh_session session,
int(*ssh_bind_message_callback)(ssh_session session, ssh_message msg, void *data),
void *data) {
session->ssh_message_callback = ssh_bind_message_callback;
session->ssh_message_callback_data = data;
}
int ssh_execute_message_callbacks(ssh_session session){
ssh_message msg=NULL;
int ret;
ssh_handle_packets(session, SSH_TIMEOUT_NONBLOCKING);
if(!session->ssh_message_list)
return SSH_OK;
if(session->ssh_message_callback){
while((msg=ssh_message_pop_head(session)) != NULL) {
ret=session->ssh_message_callback(session,msg,
session->ssh_message_callback_data);
if(ret==1){
ret = ssh_message_reply_default(msg);
ssh_message_free(msg);
if(ret != SSH_OK)
return ret;
} else {
ssh_message_free(msg);
}
}
} else {
while((msg=ssh_message_pop_head(session)) != NULL) {
ret = ssh_message_reply_default(msg);
ssh_message_free(msg);
if(ret != SSH_OK)
return ret;
}
}
return SSH_OK;
}
int ssh_send_keepalive(ssh_session session)
{
/* TODO check the reply and all that */
struct ssh_string_struct *req;
int reply = 1;
int rc = SSH_ERROR;
req = ssh_string_from_char("keepalive@openssh.com");
if (req == NULL) {
ssh_set_error_oom(session);
goto out;
}
if (buffer_add_u8(session->out_buffer, SSH2_MSG_GLOBAL_REQUEST) < 0 ||
buffer_add_ssh_string(session->out_buffer, req) < 0 ||
buffer_add_u8(session->out_buffer, reply == 0 ? 0 : 1) < 0) {
ssh_set_error_oom(session);
goto out;
}
if (packet_send(session) == SSH_ERROR)
goto out;
ssh_handle_packets(session, 0);
SSH_LOG(SSH_LOG_PACKET, "Sent a keepalive");
rc = SSH_OK;
out:
ssh_string_free(req);
return rc;
}
/** @} */
/* vim: set ts=4 sw=4 et cindent: */
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