1 /* 	$OpenBSD: test_kex.c,v 1.5 2020/12/29 01:02:15 djm Exp $ */
2 /*
3  * Regress test KEX
4  *
5  * Placed in the public domain
6  */
7 
8 #include <sys/types.h>
9 #include <sys/param.h>
10 #include <stdio.h>
11 #include <stdint.h>
12 #include <stdlib.h>
13 #include <string.h>
14 
15 #include "test_helper.h"
16 
17 #include "ssherr.h"
18 #include "ssh_api.h"
19 #include "sshbuf.h"
20 #include "packet.h"
21 #include "myproposal.h"
22 
23 void kex_tests(void);
24 static int do_debug = 0;
25 
26 static int
27 do_send_and_receive(struct ssh *from, struct ssh *to)
28 {
29 	u_char type;
30 	size_t len;
31 	const u_char *buf;
32 	int r;
33 
34 	for (;;) {
35 		if ((r = ssh_packet_next(from, &type)) != 0) {
36 			fprintf(stderr, "ssh_packet_next: %s\n", ssh_err(r));
37 			return r;
38 		}
39 		if (type != 0)
40 			return 0;
41 		buf = ssh_output_ptr(from, &len);
42 		if (do_debug)
43 			printf("%zu", len);
44 		if (len == 0)
45 			return 0;
46 		if ((r = ssh_output_consume(from, len)) != 0 ||
47 		    (r = ssh_input_append(to, buf, len)) != 0)
48 			return r;
49 	}
50 }
51 
52 static void
53 run_kex(struct ssh *client, struct ssh *server)
54 {
55 	int r = 0;
56 
57 	while (!server->kex->done || !client->kex->done) {
58 		if (do_debug)
59 			printf(" S:");
60 		if ((r = do_send_and_receive(server, client)))
61 			break;
62 		if (do_debug)
63 			printf(" C:");
64 		if ((r = do_send_and_receive(client, server)))
65 			break;
66 	}
67 	if (do_debug)
68 		printf("done: %s\n", ssh_err(r));
69 	ASSERT_INT_EQ(r, 0);
70 	ASSERT_INT_EQ(server->kex->done, 1);
71 	ASSERT_INT_EQ(client->kex->done, 1);
72 }
73 
74 static void
75 do_kex_with_key(char *kex, int keytype, int bits)
76 {
77 	struct ssh *client = NULL, *server = NULL, *server2 = NULL;
78 	struct sshkey *private, *public;
79 	struct sshbuf *state;
80 	struct kex_params kex_params;
81 	char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
82 	char *keyname = NULL;
83 
84 	TEST_START("sshkey_generate");
85 	ASSERT_INT_EQ(sshkey_generate(keytype, bits, &private), 0);
86 	TEST_DONE();
87 
88 	TEST_START("sshkey_from_private");
89 	ASSERT_INT_EQ(sshkey_from_private(private, &public), 0);
90 	TEST_DONE();
91 
92 	TEST_START("ssh_init");
93 	memcpy(kex_params.proposal, myproposal, sizeof(myproposal));
94 	if (kex != NULL)
95 		kex_params.proposal[PROPOSAL_KEX_ALGS] = kex;
96 	keyname = strdup(sshkey_ssh_name(private));
97 	ASSERT_PTR_NE(keyname, NULL);
98 	kex_params.proposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = keyname;
99 	ASSERT_INT_EQ(ssh_init(&client, 0, &kex_params), 0);
100 	ASSERT_INT_EQ(ssh_init(&server, 1, &kex_params), 0);
101 	ASSERT_PTR_NE(client, NULL);
102 	ASSERT_PTR_NE(server, NULL);
103 	TEST_DONE();
104 
105 	TEST_START("ssh_add_hostkey");
106 	ASSERT_INT_EQ(ssh_add_hostkey(server, private), 0);
107 	ASSERT_INT_EQ(ssh_add_hostkey(client, public), 0);
108 	TEST_DONE();
109 
110 	TEST_START("kex");
111 	run_kex(client, server);
112 	TEST_DONE();
113 
114 	TEST_START("rekeying client");
115 	ASSERT_INT_EQ(kex_send_kexinit(client), 0);
116 	run_kex(client, server);
117 	TEST_DONE();
118 
119 	TEST_START("rekeying server");
120 	ASSERT_INT_EQ(kex_send_kexinit(server), 0);
121 	run_kex(client, server);
122 	TEST_DONE();
123 
124 	TEST_START("ssh_packet_get_state");
125 	state = sshbuf_new();
126 	ASSERT_PTR_NE(state, NULL);
127 	ASSERT_INT_EQ(ssh_packet_get_state(server, state), 0);
128 	ASSERT_INT_GE(sshbuf_len(state), 1);
129 	TEST_DONE();
130 
131 	TEST_START("ssh_packet_set_state");
132 	server2 = NULL;
133 	ASSERT_INT_EQ(ssh_init(&server2, 1, NULL), 0);
134 	ASSERT_PTR_NE(server2, NULL);
135 	ASSERT_INT_EQ(ssh_add_hostkey(server2, private), 0);
136 	ASSERT_INT_EQ(ssh_packet_set_state(server2, state), 0);
137 	ASSERT_INT_EQ(sshbuf_len(state), 0);
138 	sshbuf_free(state);
139 	ASSERT_PTR_NE(server2->kex, NULL);
140 	/* XXX we need to set the callbacks */
141 	server2->kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
142 	server2->kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
143 	server2->kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
144 	server2->kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
145 	server2->kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
146 	server2->kex->kex[KEX_C25519_SHA256] = kex_gen_server;
147 	server2->kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
148 	server2->kex->load_host_public_key = server->kex->load_host_public_key;
149 	server2->kex->load_host_private_key = server->kex->load_host_private_key;
150 	server2->kex->sign = server->kex->sign;
151 	TEST_DONE();
152 
153 	TEST_START("rekeying server2");
154 	ASSERT_INT_EQ(kex_send_kexinit(server2), 0);
155 	run_kex(client, server2);
156 	ASSERT_INT_EQ(kex_send_kexinit(client), 0);
157 	run_kex(client, server2);
158 	TEST_DONE();
159 
160 	TEST_START("cleanup");
161 	sshkey_free(private);
162 	sshkey_free(public);
163 	ssh_free(client);
164 	ssh_free(server);
165 	ssh_free(server2);
166 	free(keyname);
167 	TEST_DONE();
168 }
169 
170 static void
171 do_kex(char *kex)
172 {
173 	do_kex_with_key(kex, KEY_RSA, 2048);
174 	do_kex_with_key(kex, KEY_DSA, 1024);
175 	do_kex_with_key(kex, KEY_ECDSA, 256);
176 	do_kex_with_key(kex, KEY_ED25519, 256);
177 }
178 
179 void
180 kex_tests(void)
181 {
182 	do_kex("curve25519-sha256@libssh.org");
183 	do_kex("ecdh-sha2-nistp256");
184 	do_kex("ecdh-sha2-nistp384");
185 	do_kex("ecdh-sha2-nistp521");
186 	do_kex("diffie-hellman-group-exchange-sha256");
187 	do_kex("diffie-hellman-group-exchange-sha1");
188 	do_kex("diffie-hellman-group14-sha1");
189 	do_kex("diffie-hellman-group1-sha1");
190 	do_kex("sntrup761x25519-sha512@openssh.com");
191 }
192