/* Logs password auth attempts. Always replies with SSH_MESSAGE_USERAUTH_FAILURE. */
int handle_auth(ssh_session session) {
struct connection con;
con.session = session;
/* Perform key exchange. */
if (ssh_handle_key_exchange(con.session)) {
fprintf(stderr, "Error exchanging keys: `%s'.\n", ssh_get_error(con.session));
return -1;
}
if (DEBUG) { printf("Successful key exchange.\n"); }
/* Wait for a message, which should be an authentication attempt. Send the default
* reply if it isn't. Log the attempt and quit. */
while (1) {
if ((con.message = ssh_message_get(con.session)) == NULL) {
break;
}
/* Log the authentication request and disconnect. */
if (ssh_message_subtype(con.message) == SSH_AUTH_METHOD_PASSWORD) {
log_attempt(&con);
}
else {
if (DEBUG) { fprintf(stderr, "Not a password authentication attempt.\n"); }
}
/* Send the default message regardless of the request type. */
ssh_message_reply_default(con.message);
ssh_message_free(con.message);
}
if (DEBUG) { printf("Exiting child.\n"); }
return 0;
}
CHANNEL *recv_channel(SSH_SESSION *session){
CHANNEL *chan=NULL;
SSH_MESSAGE *message;
int sftp=0;
do {
message=ssh_message_get(session);
if(message){
switch(ssh_message_type(message)){
case SSH_CHANNEL_REQUEST_OPEN:
if(ssh_message_subtype(message)==SSH_CHANNEL_SESSION){
chan=ssh_message_channel_request_open_reply_accept(message);
break;
}
default:
ssh_message_reply_default(message);
}
ssh_message_free(message);
}
} while(message && !chan);
if(!chan)
return NULL;
do {
message=ssh_message_get(session);
if(message && ssh_message_type(message)==SSH_CHANNEL_REQUEST &&
ssh_message_subtype(message)==SSH_CHANNEL_REQUEST_SUBSYSTEM){
if(!strcmp(ssh_message_channel_request_subsystem(message),"sftp")){
sftp=1;
ssh_message_channel_request_reply_success(message);
break;
}
}
if(!sftp){
ssh_message_reply_default(message);
}
ssh_message_free(message);
} while (message && !sftp);
if(!message)
return NULL;
return chan;
}
static int authenticate(ssh_session session) {
ssh_message message;
do {
message=ssh_message_get(session);
if(!message)
break;
switch(ssh_message_type(message)){
case SSH_REQUEST_AUTH:
switch(ssh_message_subtype(message)){
case SSH_AUTH_METHOD_PASSWORD:
printf("User %s wants to auth with pass %s\n",
ssh_message_auth_user(message),
ssh_message_auth_password(message));
if(auth_password(ssh_message_auth_user(message),
ssh_message_auth_password(message))){
ssh_message_auth_reply_success(message,0);
ssh_message_free(message);
return 1;
}
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
// not authenticated, send default message
ssh_message_reply_default(message);
break;
case SSH_AUTH_METHOD_NONE:
default:
printf("User %s wants to auth with unknown auth %d\n",
ssh_message_auth_user(message),
ssh_message_subtype(message));
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
ssh_message_reply_default(message);
break;
}
break;
default:
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
ssh_message_reply_default(message);
}
ssh_message_free(message);
} while (1);
return 0;
}
// Listen for incoming SSH connections.
// When a connection is established, write all data received to stdout.
void server_pipe(char *host, int port)
{
ssh_bind b = ssh_bind_new();
ssh_session s = ssh_new();
ssh_bind_options_set(b, SSH_BIND_OPTIONS_BINDADDR, host);
ssh_bind_options_set(b, SSH_BIND_OPTIONS_BINDPORT, &port);
ssh_bind_options_set(b, SSH_BIND_OPTIONS_RSAKEY, "test-server-key");
ssh_bind_options_set(b, SSH_BIND_OPTIONS_LOG_VERBOSITY_STR, "5");
if(ssh_bind_listen(b) < 0)
session_error(b, "listen");
if(ssh_bind_accept(b, s) != SSH_OK)
session_error(b, "accept");
if(ssh_accept(s) < 0)
session_error(s, "handshake");
int state = SERVER_CONNECTED;
while(1)
{
ssh_message m = ssh_message_get(s);
if(m)
{
int type = ssh_message_type(m);
int subtype = ssh_message_subtype(m);
ssh_message_auth_set_methods(m, SSH_AUTH_METHOD_PUBLICKEY);
server_handle_message(s, m, type, subtype, &state);
ssh_message_free(m);
if(state == SERVER_CLOSED)
{
ssh_disconnect(s);
ssh_bind_free(b);
ssh_finalize();
return;
}
}
else
{
session_error(s, "session");
}
}
}
int main(int argc, char **argv){
ssh_session session;
ssh_bind sshbind;
ssh_message message;
ssh_channel chan=0;
char buf[2048];
int auth=0;
int sftp=0;
int i;
int r;
sshbind=ssh_bind_new();
session=ssh_new();
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY, KEYS_FOLDER "ssh_host_dsa_key");
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY, KEYS_FOLDER "ssh_host_rsa_key");
#ifdef HAVE_ARGP_H
/*
* Parse our arguments; every option seen by parse_opt will
* be reflected in arguments.
*/
argp_parse (&argp, argc, argv, 0, 0, sshbind);
#else
(void) argc;
(void) argv;
#endif
#ifdef WITH_PCAP
set_pcap(session);
#endif
if(ssh_bind_listen(sshbind)<0){
printf("Error listening to socket: %s\n",ssh_get_error(sshbind));
return 1;
}
r=ssh_bind_accept(sshbind,session);
if(r==SSH_ERROR){
printf("error accepting a connection : %s\n",ssh_get_error(sshbind));
return 1;
}
if (ssh_handle_key_exchange(session)) {
printf("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
return 1;
}
do {
message=ssh_message_get(session);
if(!message)
break;
switch(ssh_message_type(message)){
case SSH_REQUEST_AUTH:
switch(ssh_message_subtype(message)){
case SSH_AUTH_METHOD_PASSWORD:
printf("User %s wants to auth with pass %s\n",
ssh_message_auth_user(message),
ssh_message_auth_password(message));
if(auth_password(ssh_message_auth_user(message),
ssh_message_auth_password(message))){
auth=1;
ssh_message_auth_reply_success(message,0);
break;
}
// not authenticated, send default message
case SSH_AUTH_METHOD_NONE:
default:
ssh_message_auth_set_methods(message,SSH_AUTH_METHOD_PASSWORD);
ssh_message_reply_default(message);
break;
}
break;
default:
ssh_message_reply_default(message);
}
ssh_message_free(message);
} while (!auth);
if(!auth){
printf("auth error: %s\n",ssh_get_error(session));
ssh_disconnect(session);
return 1;
}
do {
message=ssh_message_get(session);
if(message){
switch(ssh_message_type(message)){
case SSH_REQUEST_CHANNEL_OPEN:
if(ssh_message_subtype(message)==SSH_CHANNEL_SESSION){
chan=ssh_message_channel_request_open_reply_accept(message);
break;
}
default:
ssh_message_reply_default(message);
}
ssh_message_free(message);
}
} while(message && !chan);
if(!chan){
printf("error : %s\n",ssh_get_error(session));
ssh_finalize();
return 1;
}
do {
message=ssh_message_get(session);
if(message && ssh_message_type(message)==SSH_REQUEST_CHANNEL &&
ssh_message_subtype(message)==SSH_CHANNEL_REQUEST_SHELL){
// if(!strcmp(ssh_message_channel_request_subsystem(message),"sftp")){
sftp=1;
ssh_message_channel_request_reply_success(message);
break;
// }
}
if(!sftp){
ssh_message_reply_default(message);
}
ssh_message_free(message);
} while (message && !sftp);
if(!sftp){
printf("error : %s\n",ssh_get_error(session));
return 1;
}
printf("it works !\n");
do{
i=ssh_channel_read(chan,buf, 2048, 0);
if(i>0) {
ssh_channel_write(chan, buf, i);
if (write(1,buf,i) < 0) {
printf("error writing to buffer\n");
return 1;
}
}
} while (i>0);
ssh_disconnect(session);
ssh_bind_free(sshbind);
#ifdef WITH_PCAP
cleanup_pcap();
#endif
ssh_finalize();
return 0;
}
int main(int argc, char **argv){
ssh_session session;
ssh_bind sshbind;
ssh_message message;
ssh_channel chan=0;
char buf[2048];
int auth=0;
int shell=0;
int i;
int r;
sshbind=ssh_bind_new();
session=ssh_new();
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_DSAKEY,
KEYS_FOLDER "ssh_host_dsa_key");
ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_RSAKEY,
KEYS_FOLDER "ssh_host_rsa_key");
#ifdef HAVE_ARGP_H
/*
* Parse our arguments; every option seen by parse_opt will
* be reflected in arguments.
*/
argp_parse (&argp, argc, argv, 0, 0, sshbind);
#else
(void) argc;
(void) argv;
#endif
#ifdef WITH_PCAP
set_pcap(session);
#endif
if(ssh_bind_listen(sshbind)<0){
printf("Error listening to socket: %s\n", ssh_get_error(sshbind));
return 1;
}
printf("Started sample libssh sshd on port %d\n", port);
printf("You can login as the user %s with the password %s\n", SSHD_USER,
SSHD_PASSWORD);
r = ssh_bind_accept(sshbind, session);
if(r==SSH_ERROR){
printf("Error accepting a connection: %s\n", ssh_get_error(sshbind));
return 1;
}
if (ssh_handle_key_exchange(session)) {
printf("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
return 1;
}
/* proceed to authentication */
auth = authenticate(session);
if (!auth || !authenticated) {
printf("Authentication error: %s\n", ssh_get_error(session));
ssh_disconnect(session);
return 1;
}
/* wait for a channel session */
do {
message = ssh_message_get(session);
if(message){
if(ssh_message_type(message) == SSH_REQUEST_CHANNEL_OPEN &&
ssh_message_subtype(message) == SSH_CHANNEL_SESSION) {
chan = ssh_message_channel_request_open_reply_accept(message);
ssh_message_free(message);
break;
} else {
ssh_message_reply_default(message);
ssh_message_free(message);
}
} else {
break;
}
} while(!chan);
if(!chan) {
printf("Error: cleint did not ask for a channel session (%s)\n",
ssh_get_error(session));
ssh_finalize();
return 1;
}
/* wait for a shell */
do {
message = ssh_message_get(session);
if(message != NULL) {
if(ssh_message_type(message) == SSH_REQUEST_CHANNEL &&
ssh_message_subtype(message) == SSH_CHANNEL_REQUEST_SHELL) {
shell = 1;
ssh_message_channel_request_reply_success(message);
ssh_message_free(message);
break;
}
ssh_message_reply_default(message);
ssh_message_free(message);
} else {
break;
}
} while(!shell);
if(!shell) {
printf("Error: No shell requested (%s)\n", ssh_get_error(session));
return 1;
}
printf("it works !\n");
do{
i=ssh_channel_read(chan,buf, 2048, 0);
if(i>0) {
if(*buf == '' || *buf == '')
break;
if(i == 1 && *buf == '\r')
ssh_channel_write(chan, "\r\n", 2);
else
ssh_channel_write(chan, buf, i);
if (write(1,buf,i) < 0) {
printf("error writing to buffer\n");
return 1;
}
}
} while (i>0);
ssh_channel_close(chan);
ssh_disconnect(session);
ssh_bind_free(sshbind);
#ifdef WITH_PCAP
cleanup_pcap();
#endif
ssh_finalize();
return 0;
}
static int authenticate(ssh_session session) {
ssh_message message;
name = "\n\nKeyboard-Interactive Fancy Authentication\n";
instruction = "Please enter your real name and your password";
prompts[0] = "Real name: ";
prompts[1] = "Password: "******"User %s wants to auth with pass %s\n",
ssh_message_auth_user(message),
ssh_message_auth_password(message));
if(auth_password(ssh_message_auth_user(message),
ssh_message_auth_password(message))){
ssh_message_auth_reply_success(message,0);
ssh_message_free(message);
return 1;
}
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
// not authenticated, send default message
ssh_message_reply_default(message);
break;
case SSH_AUTH_METHOD_INTERACTIVE:
if(!ssh_message_auth_kbdint_is_response(message)) {
printf("User %s wants to auth with kbdint\n",
ssh_message_auth_user(message));
ssh_message_auth_interactive_request(message, name,
instruction, 2, prompts, echo);
} else {
if(kbdint_check_response(session)) {
ssh_message_auth_reply_success(message,0);
ssh_message_free(message);
return 1;
}
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
ssh_message_reply_default(message);
}
break;
case SSH_AUTH_METHOD_NONE:
default:
printf("User %s wants to auth with unknown auth %d\n",
ssh_message_auth_user(message),
ssh_message_subtype(message));
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
ssh_message_reply_default(message);
break;
}
break;
default:
ssh_message_auth_set_methods(message,
SSH_AUTH_METHOD_PASSWORD |
SSH_AUTH_METHOD_INTERACTIVE);
ssh_message_reply_default(message);
}
ssh_message_free(message);
} while (1);
return 0;
}
