1 /* 	$OpenBSD: test_kex.c,v 1.7 2024/01/11 01:45:58 djm Exp $ */
2 /*
3  * Regress test KEX
4  *
5  * Placed in the public domain
6  */
7 
8 #include "includes.h"
9 
10 #include <sys/types.h>
11 #include <stdio.h>
12 #ifdef HAVE_STDINT_H
13 #include <stdint.h>
14 #endif
15 #include <stdlib.h>
16 #include <string.h>
17 
18 #include "../test_helper/test_helper.h"
19 
20 #include "ssherr.h"
21 #include "ssh_api.h"
22 #include "sshbuf.h"
23 #include "packet.h"
24 #include "myproposal.h"
25 
26 void kex_tests(void);
27 static int do_debug = 0;
28 
29 static int
do_send_and_receive(struct ssh * from,struct ssh * to)30 do_send_and_receive(struct ssh *from, struct ssh *to)
31 {
32 	u_char type;
33 	size_t len;
34 	const u_char *buf;
35 	int r;
36 
37 	for (;;) {
38 		if ((r = ssh_packet_next(from, &type)) != 0) {
39 			fprintf(stderr, "ssh_packet_next: %s\n", ssh_err(r));
40 			return r;
41 		}
42 		if (type != 0)
43 			return 0;
44 		buf = ssh_output_ptr(from, &len);
45 		if (do_debug)
46 			printf("%zu", len);
47 		if (len == 0)
48 			return 0;
49 		if ((r = ssh_output_consume(from, len)) != 0 ||
50 		    (r = ssh_input_append(to, buf, len)) != 0)
51 			return r;
52 	}
53 }
54 
55 static void
run_kex(struct ssh * client,struct ssh * server)56 run_kex(struct ssh *client, struct ssh *server)
57 {
58 	int r = 0;
59 
60 	while (!server->kex->done || !client->kex->done) {
61 		if (do_debug)
62 			printf(" S:");
63 		if ((r = do_send_and_receive(server, client)))
64 			break;
65 		if (do_debug)
66 			printf(" C:");
67 		if ((r = do_send_and_receive(client, server)))
68 			break;
69 	}
70 	if (do_debug)
71 		printf("done: %s\n", ssh_err(r));
72 	ASSERT_INT_EQ(r, 0);
73 	ASSERT_INT_EQ(server->kex->done, 1);
74 	ASSERT_INT_EQ(client->kex->done, 1);
75 }
76 
77 static void
do_kex_with_key(char * kex,int keytype,int bits)78 do_kex_with_key(char *kex, int keytype, int bits)
79 {
80 	struct ssh *client = NULL, *server = NULL, *server2 = NULL;
81 	struct sshkey *private, *public;
82 	struct sshbuf *state;
83 	struct kex_params kex_params;
84 	char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
85 	char *keyname = NULL;
86 
87 	TEST_START("sshkey_generate");
88 	ASSERT_INT_EQ(sshkey_generate(keytype, bits, &private), 0);
89 	TEST_DONE();
90 
91 	TEST_START("sshkey_from_private");
92 	ASSERT_INT_EQ(sshkey_from_private(private, &public), 0);
93 	TEST_DONE();
94 
95 	TEST_START("ssh_init");
96 	memcpy(kex_params.proposal, myproposal, sizeof(myproposal));
97 	if (kex != NULL)
98 		kex_params.proposal[PROPOSAL_KEX_ALGS] = kex;
99 	keyname = strdup(sshkey_ssh_name(private));
100 	ASSERT_PTR_NE(keyname, NULL);
101 	kex_params.proposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = keyname;
102 	ASSERT_INT_EQ(ssh_init(&client, 0, &kex_params), 0);
103 	ASSERT_INT_EQ(ssh_init(&server, 1, &kex_params), 0);
104 	ASSERT_PTR_NE(client, NULL);
105 	ASSERT_PTR_NE(server, NULL);
106 	TEST_DONE();
107 
108 	TEST_START("ssh_add_hostkey");
109 	ASSERT_INT_EQ(ssh_add_hostkey(server, private), 0);
110 	ASSERT_INT_EQ(ssh_add_hostkey(client, public), 0);
111 	TEST_DONE();
112 
113 	TEST_START("kex");
114 	run_kex(client, server);
115 	TEST_DONE();
116 
117 	TEST_START("rekeying client");
118 	ASSERT_INT_EQ(kex_send_kexinit(client), 0);
119 	run_kex(client, server);
120 	TEST_DONE();
121 
122 	TEST_START("rekeying server");
123 	ASSERT_INT_EQ(kex_send_kexinit(server), 0);
124 	run_kex(client, server);
125 	TEST_DONE();
126 
127 	TEST_START("ssh_packet_get_state");
128 	state = sshbuf_new();
129 	ASSERT_PTR_NE(state, NULL);
130 	ASSERT_INT_EQ(ssh_packet_get_state(server, state), 0);
131 	ASSERT_INT_GE(sshbuf_len(state), 1);
132 	TEST_DONE();
133 
134 	TEST_START("ssh_packet_set_state");
135 	server2 = NULL;
136 	ASSERT_INT_EQ(ssh_init(&server2, 1, NULL), 0);
137 	ASSERT_PTR_NE(server2, NULL);
138 	ASSERT_INT_EQ(ssh_add_hostkey(server2, private), 0);
139 	ASSERT_INT_EQ(ssh_packet_set_state(server2, state), 0);
140 	ASSERT_INT_EQ(sshbuf_len(state), 0);
141 	sshbuf_free(state);
142 	ASSERT_PTR_NE(server2->kex, NULL);
143 	/* XXX we need to set the callbacks */
144 #ifdef WITH_OPENSSL
145 	server2->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
146 	server2->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
147 	server2->kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
148 	server2->kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
149 #ifdef OPENSSL_HAS_ECC
150 	server2->kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
151 #endif /* OPENSSL_HAS_ECC */
152 #endif /* WITH_OPENSSL */
153 	server2->kex->kex[KEX_C25519_SHA256] = kex_gen_server;
154 	server2->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
155 	server2->kex->load_host_public_key = server->kex->load_host_public_key;
156 	server2->kex->load_host_private_key = server->kex->load_host_private_key;
157 	server2->kex->sign = server->kex->sign;
158 	TEST_DONE();
159 
160 	TEST_START("rekeying server2");
161 	ASSERT_INT_EQ(kex_send_kexinit(server2), 0);
162 	run_kex(client, server2);
163 	ASSERT_INT_EQ(kex_send_kexinit(client), 0);
164 	run_kex(client, server2);
165 	TEST_DONE();
166 
167 	TEST_START("cleanup");
168 	sshkey_free(private);
169 	sshkey_free(public);
170 	ssh_free(client);
171 	ssh_free(server);
172 	ssh_free(server2);
173 	free(keyname);
174 	TEST_DONE();
175 }
176 
177 static void
do_kex(char * kex)178 do_kex(char *kex)
179 {
180 #ifdef WITH_OPENSSL
181 	do_kex_with_key(kex, KEY_RSA, 2048);
182 #ifdef WITH_DSA
183 	do_kex_with_key(kex, KEY_DSA, 1024);
184 #endif
185 #ifdef OPENSSL_HAS_ECC
186 	do_kex_with_key(kex, KEY_ECDSA, 256);
187 #endif /* OPENSSL_HAS_ECC */
188 #endif /* WITH_OPENSSL */
189 	do_kex_with_key(kex, KEY_ED25519, 256);
190 }
191 
192 void
kex_tests(void)193 kex_tests(void)
194 {
195 	do_kex("curve25519-sha256@libssh.org");
196 #ifdef WITH_OPENSSL
197 #ifdef OPENSSL_HAS_ECC
198 	do_kex("ecdh-sha2-nistp256");
199 	do_kex("ecdh-sha2-nistp384");
200 	do_kex("ecdh-sha2-nistp521");
201 #endif /* OPENSSL_HAS_ECC */
202 	do_kex("diffie-hellman-group-exchange-sha256");
203 	do_kex("diffie-hellman-group-exchange-sha1");
204 	do_kex("diffie-hellman-group14-sha1");
205 	do_kex("diffie-hellman-group1-sha1");
206 # ifdef USE_SNTRUP761X25519
207 	do_kex("sntrup761x25519-sha512@openssh.com");
208 # endif /* USE_SNTRUP761X25519 */
209 #endif /* WITH_OPENSSL */
210 }
211