lbbs/src/test_ssh_server.c

/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * test_ssh_server
 *   - tester for network server with SSH support
 *
 * Copyright (C) 2004-2025  Leaflet <leaflet@leafok.com>
 */

// This test was written based on libssh example/proxy.c

#include "log.h"
#include <stdio.h>
#include <libssh/callbacks.h>
#include <libssh/libssh.h>
#include <libssh/server.h>

enum test_ssh_server_constant_t
{
        BUF_SIZE = 2048,
};

static const char SSH_HOST_RSA_KEYFILE[] = "../conf/ssh_host_rsa_key";

static const char USER[] = "test";
static const char PASSWORD[] = "123456";

static ssh_channel SSH_channel;
static int authenticated = 0;
static int tries = 0;
static int error = 0;

static int auth_password(ssh_session session, const char *user,
                                                 const char *password, void *userdata)
{
        (void)userdata;

        log_common("Authenticating user %s pwd %s\n", user, password);
        if (strcmp(user, USER) == 0 && strcmp(password, PASSWORD) == 0)
        {
                authenticated = 1;
                log_common("Authenticated\n");
                return SSH_AUTH_SUCCESS;
        }
        if (tries >= 3)
        {
                log_error("Too many authentication tries\n");
                ssh_disconnect(session);
                error = 1;
                return SSH_AUTH_DENIED;
        }
        tries++;
        return SSH_AUTH_DENIED;
}

static int pty_request(ssh_session session, ssh_channel channel, const char *term,
                                           int x, int y, int px, int py, void *userdata)
{
        (void)session;
        (void)channel;
        (void)term;
        (void)x;
        (void)y;
        (void)px;
        (void)py;
        (void)userdata;
        log_common("Allocated terminal\n");
        return 0;
}

static int shell_request(ssh_session session, ssh_channel channel, void *userdata)
{
        (void)session;
        (void)channel;
        (void)userdata;
        log_common("Allocated shell\n");
        return 0;
}

struct ssh_channel_callbacks_struct channel_cb = {
        .channel_pty_request_function = pty_request,
        .channel_shell_request_function = shell_request};

static ssh_channel channel_open(ssh_session session, void *userdata)
{
        (void)session;
        (void)userdata;

        if (SSH_channel != NULL)
                return NULL;

        log_common("Allocated session channel\n");
        SSH_channel = ssh_channel_new(session);
        ssh_callbacks_init(&channel_cb);
        ssh_set_channel_callbacks(SSH_channel, &channel_cb);

        return SSH_channel;
}

int ssh_server(const char *hostaddr, unsigned int port)
{
        ssh_bind sshbind;
        ssh_session session;
        ssh_event event;

        struct ssh_server_callbacks_struct cb = {
                .userdata = NULL,
                .auth_password_function = auth_password,
                .channel_open_request_session_function = channel_open};

        long int ssh_timeout = 0;

        char buf[BUF_SIZE];
        char host[128] = "";
        int i, r;

        int ssh_log_level = SSH_LOG_PROTOCOL;

        ssh_init();

        sshbind = ssh_bind_new();

        if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, hostaddr) < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT, &port) < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, SSH_HOST_RSA_KEYFILE) < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY_ALGORITHMS, "ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_PUBKEY_ACCEPTED_KEY_TYPES, "ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_KEY_EXCHANGE, "curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HMAC_C_S, "umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HMAC_S_C, "umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_CIPHERS_C_S, "chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_CIPHERS_S_C, "chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com") < 0 ||
                ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY, &ssh_log_level) < 0)
        {
                log_error("Error setting SSH bind options: %s\n", ssh_get_error(sshbind));
                ssh_bind_free(sshbind);
                return -1;
        }

        if (ssh_bind_listen(sshbind) < 0)
        {
                log_error("Error listening at SSH server port: %s\n", ssh_get_error(sshbind));
                ssh_bind_free(sshbind);
                return -1;
        }

        while (1)
        {
                session = ssh_new();

                if (ssh_bind_accept(sshbind, session) == SSH_OK)
                {
                        pid_t pid = fork();
                        switch (pid)
                        {
                        case 0:
                                ssh_bind_free(sshbind);

                                ssh_callbacks_init(&cb);
                                ssh_set_server_callbacks(session, &cb);

                                ssh_timeout = 60; // second
                                if (ssh_options_set(session, SSH_OPTIONS_TIMEOUT, &ssh_timeout) < 0)
                                {
                                        log_error("Error setting SSH options: %s\n", ssh_get_error(session));
                                        ssh_disconnect(session);
                                        _exit(1);
                                }

                                if (ssh_handle_key_exchange(session))
                                {
                                        log_error("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
                                        ssh_disconnect(session);
                                        _exit(1);
                                }
                                ssh_set_auth_methods(session, SSH_AUTH_METHOD_PASSWORD | SSH_AUTH_METHOD_GSSAPI_MIC);

                                event = ssh_event_new();
                                ssh_event_add_session(event, session);

                                while (!(authenticated && SSH_channel != NULL))
                                {
                                        if (error)
                                                break;
                                        r = ssh_event_dopoll(event, -1);
                                        if (r == SSH_ERROR)
                                        {
                                                log_error("Error : %s\n", ssh_get_error(session));
                                                ssh_disconnect(session);
                                                _exit(1);
                                        }
                                }

                                if (error)
                                {
                                        log_error("Error, exiting loop\n");
                                        _exit(1);
                                }
                                else
                                {
                                        log_common("Authenticated and got a channel\n");
                                }

                                ssh_timeout = 0;
                                if (ssh_options_set(session, SSH_OPTIONS_TIMEOUT, &ssh_timeout) < 0)
                                {
                                        log_error("Error setting SSH options: %s\n", ssh_get_error(session));
                                        ssh_disconnect(session);
                                        _exit(1);
                                }

                                snprintf(buf, sizeof(buf), "Hello, welcome to the Sample SSH proxy.\r\nPlease select your destination: ");
                                ssh_channel_write(SSH_channel, buf, (uint32_t)strlen(buf));
                                do
                                {
                                        i = ssh_channel_read(SSH_channel, buf, sizeof(buf), 0);
                                        if (i > 0)
                                        {
                                                ssh_channel_write(SSH_channel, buf, (uint32_t)i);
                                                if (strlen(host) + (size_t)i < sizeof(host))
                                                {
                                                        strncat(host, buf, (size_t)i);
                                                }
                                                if (strchr(host, '\x0d'))
                                                {
                                                        *strchr(host, '\x0d') = '\0';
                                                        ssh_channel_write(SSH_channel, "\n", 1);
                                                        break;
                                                }
                                        }
                                        else
                                        {
                                                log_error("Error: %s\n", ssh_get_error(session));
                                                _exit(1);
                                        }
                                } while (i > 0);
                                snprintf(buf, sizeof(buf), "Trying to connect to \"%s\"\r\n", host);
                                ssh_channel_write(SSH_channel, buf, (uint32_t)strlen(buf));
                                log_common("%s", buf);

                                ssh_disconnect(session);
                                ssh_free(session);

                                _exit(0);
                        case -1:
                                log_error("Failed to fork\n");
                                break;
                        }
                }
                else
                {
                        log_error("%s\n", ssh_get_error(sshbind));
                }

                /* Since the session has been passed to a child fork, do some cleaning
                 * up at the parent process. */
                ssh_disconnect(session);
                ssh_free(session);
        }

        ssh_bind_free(sshbind);
        ssh_finalize();

        return 0;
}

int main(int argc, char *argv[])
{
        if (log_begin("../log/bbsd.log", "../log/error.log") < 0)
        {
                printf("Open log error\n");
                return -1;
        }

        log_common_redir(STDOUT_FILENO);
        log_error_redir(STDERR_FILENO);

        ssh_server("0.0.0.0", 2322);

        log_end();

        return 0;
}
1	sysadm	1.12	/* SPDX-License-Identifier: GPL-3.0-or-later */
2			/*
3			* test_ssh_server
4			* - tester for network server with SSH support
5			*
6	sysadm	1.13	* Copyright (C) 2004-2025 Leaflet <leaflet@leafok.com>
7	sysadm	1.12	*/
8	sysadm	1.8
9			// This test was written based on libssh example/proxy.c
10	sysadm	1.7
11	sysadm	1.1	#include "log.h"
12			#include <stdio.h>
13	sysadm	1.9	#include <libssh/callbacks.h>
14	sysadm	1.1	#include <libssh/libssh.h>
15			#include <libssh/server.h>
16
17	sysadm	1.14	enum test_ssh_server_constant_t
18			{
19			BUF_SIZE = 2048,
20			};
21	sysadm	1.2
22	sysadm	1.14	static const char SSH_HOST_RSA_KEYFILE[] = "../conf/ssh_host_rsa_key";
23	sysadm	1.2
24	sysadm	1.14	static const char USER[] = "test";
25			static const char PASSWORD[] = "123456";
26	sysadm	1.2
27	sysadm	1.4	static ssh_channel SSH_channel;
28	sysadm	1.2	static int authenticated = 0;
29			static int tries = 0;
30			static int error = 0;
31
32			static int auth_password(ssh_session session, const char *user,
33			const char password, void userdata)
34	sysadm	1.1	{
35	sysadm	1.2	(void)userdata;
36
37	sysadm	1.3	log_common("Authenticating user %s pwd %s\n", user, password);
38	sysadm	1.2	if (strcmp(user, USER) == 0 && strcmp(password, PASSWORD) == 0)
39	sysadm	1.1	{
40	sysadm	1.2	authenticated = 1;
41	sysadm	1.3	log_common("Authenticated\n");
42	sysadm	1.1	return SSH_AUTH_SUCCESS;
43			}
44	sysadm	1.2	if (tries >= 3)
45			{
46			log_error("Too many authentication tries\n");
47			ssh_disconnect(session);
48			error = 1;
49			return SSH_AUTH_DENIED;
50			}
51			tries++;
52			return SSH_AUTH_DENIED;
53			}
54
55			static int pty_request(ssh_session session, ssh_channel channel, const char *term,
56			int x, int y, int px, int py, void *userdata)
57			{
58			(void)session;
59			(void)channel;
60			(void)term;
61			(void)x;
62			(void)y;
63			(void)px;
64			(void)py;
65			(void)userdata;
66	sysadm	1.3	log_common("Allocated terminal\n");
67	sysadm	1.2	return 0;
68			}
69
70			static int shell_request(ssh_session session, ssh_channel channel, void *userdata)
71			{
72			(void)session;
73			(void)channel;
74			(void)userdata;
75	sysadm	1.3	log_common("Allocated shell\n");
76	sysadm	1.2	return 0;
77			}
78	sysadm	1.4
79	sysadm	1.2	struct ssh_channel_callbacks_struct channel_cb = {
80			.channel_pty_request_function = pty_request,
81			.channel_shell_request_function = shell_request};
82
83	sysadm	1.11	static ssh_channel channel_open(ssh_session session, void *userdata)
84	sysadm	1.2	{
85			(void)session;
86			(void)userdata;
87	sysadm	1.1
88	sysadm	1.4	if (SSH_channel != NULL)
89	sysadm	1.2	return NULL;
90
91	sysadm	1.3	log_common("Allocated session channel\n");
92	sysadm	1.4	SSH_channel = ssh_channel_new(session);
93	sysadm	1.2	ssh_callbacks_init(&channel_cb);
94	sysadm	1.4	ssh_set_channel_callbacks(SSH_channel, &channel_cb);
95	sysadm	1.2
96	sysadm	1.4	return SSH_channel;
97	sysadm	1.1	}
98
99			int ssh_server(const char *hostaddr, unsigned int port)
100			{
101	sysadm	1.4	ssh_bind sshbind;
102	sysadm	1.2	ssh_session session;
103			ssh_event event;
104
105	sysadm	1.1	struct ssh_server_callbacks_struct cb = {
106			.userdata = NULL,
107	sysadm	1.2	.auth_password_function = auth_password,
108	sysadm	1.11	.channel_open_request_session_function = channel_open};
109	sysadm	1.2
110	sysadm	1.10	long int ssh_timeout = 0;
111
112	sysadm	1.2	char buf[BUF_SIZE];
113			char host[128] = "";
114			int i, r;
115
116	sysadm	1.6	int ssh_log_level = SSH_LOG_PROTOCOL;
117	sysadm	1.1
118			ssh_init();
119
120			sshbind = ssh_bind_new();
121
122			if (ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDADDR, hostaddr) < 0 \|\|
123			ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_BINDPORT, &port) < 0 \|\|
124	sysadm	1.6	ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY, SSH_HOST_RSA_KEYFILE) < 0 \|\|
125	sysadm	1.5	ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HOSTKEY_ALGORITHMS, "ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256") < 0 \|\|
126	sysadm	1.6	ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_PUBKEY_ACCEPTED_KEY_TYPES, "ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256") < 0 \|\|
127	sysadm	1.5	ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_KEY_EXCHANGE, "curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1") < 0 \|\|
128			ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HMAC_C_S, "umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1") < 0 \|\|
129			ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_HMAC_S_C, "umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1") < 0 \|\|
130			ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_CIPHERS_C_S, "chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com") < 0 \|\|
131			ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_CIPHERS_S_C, "chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com") < 0 \|\|
132	sysadm	1.1	ssh_bind_options_set(sshbind, SSH_BIND_OPTIONS_LOG_VERBOSITY, &ssh_log_level) < 0)
133			{
134			log_error("Error setting SSH bind options: %s\n", ssh_get_error(sshbind));
135	sysadm	1.2	ssh_bind_free(sshbind);
136	sysadm	1.1	return -1;
137			}
138
139			if (ssh_bind_listen(sshbind) < 0)
140			{
141			log_error("Error listening at SSH server port: %s\n", ssh_get_error(sshbind));
142	sysadm	1.2	ssh_bind_free(sshbind);
143	sysadm	1.1	return -1;
144			}
145
146			while (1)
147			{
148			session = ssh_new();
149
150	sysadm	1.2	if (ssh_bind_accept(sshbind, session) == SSH_OK)
151	sysadm	1.1	{
152	sysadm	1.2	pid_t pid = fork();
153			switch (pid)
154			{
155			case 0:
156			ssh_bind_free(sshbind);
157
158			ssh_callbacks_init(&cb);
159			ssh_set_server_callbacks(session, &cb);
160
161	sysadm	1.10	ssh_timeout = 60; // second
162			if (ssh_options_set(session, SSH_OPTIONS_TIMEOUT, &ssh_timeout) < 0)
163			{
164			log_error("Error setting SSH options: %s\n", ssh_get_error(session));
165			ssh_disconnect(session);
166			_exit(1);
167			}
168
169	sysadm	1.2	if (ssh_handle_key_exchange(session))
170			{
171			log_error("ssh_handle_key_exchange: %s\n", ssh_get_error(session));
172	sysadm	1.10	ssh_disconnect(session);
173			_exit(1);
174	sysadm	1.2	}
175			ssh_set_auth_methods(session, SSH_AUTH_METHOD_PASSWORD \| SSH_AUTH_METHOD_GSSAPI_MIC);
176
177			event = ssh_event_new();
178			ssh_event_add_session(event, session);
179
180	sysadm	1.4	while (!(authenticated && SSH_channel != NULL))
181	sysadm	1.2	{
182			if (error)
183			break;
184			r = ssh_event_dopoll(event, -1);
185			if (r == SSH_ERROR)
186			{
187			log_error("Error : %s\n", ssh_get_error(session));
188			ssh_disconnect(session);
189			_exit(1);
190			}
191			}
192
193			if (error)
194			{
195			log_error("Error, exiting loop\n");
196			_exit(1);
197			}
198			else
199			{
200	sysadm	1.3	log_common("Authenticated and got a channel\n");
201	sysadm	1.2	}
202
203	sysadm	1.10	ssh_timeout = 0;
204			if (ssh_options_set(session, SSH_OPTIONS_TIMEOUT, &ssh_timeout) < 0)
205			{
206			log_error("Error setting SSH options: %s\n", ssh_get_error(session));
207			ssh_disconnect(session);
208			_exit(1);
209			}
210
211	sysadm	1.2	snprintf(buf, sizeof(buf), "Hello, welcome to the Sample SSH proxy.\r\nPlease select your destination: ");
212	sysadm	1.4	ssh_channel_write(SSH_channel, buf, (uint32_t)strlen(buf));
213	sysadm	1.2	do
214			{
215	sysadm	1.4	i = ssh_channel_read(SSH_channel, buf, sizeof(buf), 0);
216	sysadm	1.2	if (i > 0)
217			{
218	sysadm	1.4	ssh_channel_write(SSH_channel, buf, (uint32_t)i);
219	sysadm	1.2	if (strlen(host) + (size_t)i < sizeof(host))
220			{
221			strncat(host, buf, (size_t)i);
222			}
223			if (strchr(host, '\x0d'))
224			{
225			*strchr(host, '\x0d') = '\0';
226	sysadm	1.4	ssh_channel_write(SSH_channel, "\n", 1);
227	sysadm	1.2	break;
228			}
229			}
230			else
231			{
232			log_error("Error: %s\n", ssh_get_error(session));
233			_exit(1);
234			}
235			} while (i > 0);
236			snprintf(buf, sizeof(buf), "Trying to connect to \"%s\"\r\n", host);
237	sysadm	1.4	ssh_channel_write(SSH_channel, buf, (uint32_t)strlen(buf));
238	sysadm	1.3	log_common("%s", buf);
239	sysadm	1.2
240			ssh_disconnect(session);
241			ssh_free(session);
242
243			_exit(0);
244			case -1:
245			log_error("Failed to fork\n");
246			break;
247			}
248	sysadm	1.1	}
249	sysadm	1.2	else
250	sysadm	1.1	{
251	sysadm	1.2	log_error("%s\n", ssh_get_error(sshbind));
252	sysadm	1.1	}
253
254	sysadm	1.2	/* Since the session has been passed to a child fork, do some cleaning
255			* up at the parent process. */
256	sysadm	1.1	ssh_disconnect(session);
257			ssh_free(session);
258			}
259
260			ssh_bind_free(sshbind);
261			ssh_finalize();
262
263			return 0;
264			}
265
266			int main(int argc, char *argv[])
267			{
268			if (log_begin("../log/bbsd.log", "../log/error.log") < 0)
269			{
270			printf("Open log error\n");
271			return -1;
272			}
273
274	sysadm	1.3	log_common_redir(STDOUT_FILENO);
275			log_error_redir(STDERR_FILENO);
276	sysadm	1.1
277			ssh_server("0.0.0.0", 2322);
278
279			log_end();
280
281			return 0;
282			}
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