1/*
2 * TLSv1 common routines
3 * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Alternatively, this software may be distributed under the terms of BSD
10 * license.
11 *
12 * See README and COPYING for more details.
13 */
14
15#include "includes.h"
16
17#include "common.h"
18#include "x509v3.h"
19#include "tlsv1_common.h"
20
21
22/*
23 * TODO:
24 * RFC 2246 Section 9: Mandatory to implement TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA
25 * Add support for commonly used cipher suites; don't bother with exportable
26 * suites.
27 */
28
29static const struct tls_cipher_suite tls_cipher_suites[] = {
30	{ TLS_NULL_WITH_NULL_NULL, TLS_KEY_X_NULL, TLS_CIPHER_NULL,
31	  TLS_HASH_NULL },
32	{ TLS_RSA_WITH_RC4_128_MD5, TLS_KEY_X_RSA, TLS_CIPHER_RC4_128,
33	  TLS_HASH_MD5 },
34	{ TLS_RSA_WITH_RC4_128_SHA, TLS_KEY_X_RSA, TLS_CIPHER_RC4_128,
35	  TLS_HASH_SHA },
36	{ TLS_RSA_WITH_DES_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_DES_CBC,
37	  TLS_HASH_SHA },
38	{ TLS_RSA_WITH_3DES_EDE_CBC_SHA, TLS_KEY_X_RSA,
39	  TLS_CIPHER_3DES_EDE_CBC, TLS_HASH_SHA },
40 	{ TLS_DH_anon_WITH_RC4_128_MD5, TLS_KEY_X_DH_anon,
41	  TLS_CIPHER_RC4_128, TLS_HASH_MD5 },
42 	{ TLS_DH_anon_WITH_DES_CBC_SHA, TLS_KEY_X_DH_anon,
43	  TLS_CIPHER_DES_CBC, TLS_HASH_SHA },
44 	{ TLS_DH_anon_WITH_3DES_EDE_CBC_SHA, TLS_KEY_X_DH_anon,
45	  TLS_CIPHER_3DES_EDE_CBC, TLS_HASH_SHA },
46	{ TLS_RSA_WITH_AES_128_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_AES_128_CBC,
47	  TLS_HASH_SHA },
48	{ TLS_DH_anon_WITH_AES_128_CBC_SHA, TLS_KEY_X_DH_anon,
49	  TLS_CIPHER_AES_128_CBC, TLS_HASH_SHA },
50	{ TLS_RSA_WITH_AES_256_CBC_SHA, TLS_KEY_X_RSA, TLS_CIPHER_AES_256_CBC,
51	  TLS_HASH_SHA },
52	{ TLS_DH_anon_WITH_AES_256_CBC_SHA, TLS_KEY_X_DH_anon,
53	  TLS_CIPHER_AES_256_CBC, TLS_HASH_SHA }
54};
55
56#define NUM_ELEMS(a) (sizeof(a) / sizeof((a)[0]))
57#define NUM_TLS_CIPHER_SUITES NUM_ELEMS(tls_cipher_suites)
58
59
60static const struct tls_cipher_data tls_ciphers[] = {
61	{ TLS_CIPHER_NULL,         TLS_CIPHER_STREAM,  0,  0,  0,
62	  CRYPTO_CIPHER_NULL },
63	{ TLS_CIPHER_IDEA_CBC,     TLS_CIPHER_BLOCK,  16, 16,  8,
64	  CRYPTO_CIPHER_NULL },
65	{ TLS_CIPHER_RC2_CBC_40,   TLS_CIPHER_BLOCK,   5, 16,  0,
66	  CRYPTO_CIPHER_ALG_RC2 },
67	{ TLS_CIPHER_RC4_40,       TLS_CIPHER_STREAM,  5, 16,  0,
68	  CRYPTO_CIPHER_ALG_RC4 },
69	{ TLS_CIPHER_RC4_128,      TLS_CIPHER_STREAM, 16, 16,  0,
70	  CRYPTO_CIPHER_ALG_RC4 },
71	{ TLS_CIPHER_DES40_CBC,    TLS_CIPHER_BLOCK,   5,  8,  8,
72	  CRYPTO_CIPHER_ALG_DES },
73	{ TLS_CIPHER_DES_CBC,      TLS_CIPHER_BLOCK,   8,  8,  8,
74	  CRYPTO_CIPHER_ALG_DES },
75	{ TLS_CIPHER_3DES_EDE_CBC, TLS_CIPHER_BLOCK,  24, 24,  8,
76	  CRYPTO_CIPHER_ALG_3DES },
77	{ TLS_CIPHER_AES_128_CBC,  TLS_CIPHER_BLOCK,  16, 16, 16,
78	  CRYPTO_CIPHER_ALG_AES },
79	{ TLS_CIPHER_AES_256_CBC,  TLS_CIPHER_BLOCK,  32, 32, 16,
80	  CRYPTO_CIPHER_ALG_AES }
81};
82
83#define NUM_TLS_CIPHER_DATA NUM_ELEMS(tls_ciphers)
84
85
86/**
87 * tls_get_cipher_suite - Get TLS cipher suite
88 * @suite: Cipher suite identifier
89 * Returns: Pointer to the cipher data or %NULL if not found
90 */
91const struct tls_cipher_suite * tls_get_cipher_suite(u16 suite)
92{
93	size_t i;
94	for (i = 0; i < NUM_TLS_CIPHER_SUITES; i++)
95		if (tls_cipher_suites[i].suite == suite)
96			return &tls_cipher_suites[i];
97	return NULL;
98}
99
100
101const struct tls_cipher_data * tls_get_cipher_data(tls_cipher cipher)
102{
103	size_t i;
104	for (i = 0; i < NUM_TLS_CIPHER_DATA; i++)
105		if (tls_ciphers[i].cipher == cipher)
106			return &tls_ciphers[i];
107	return NULL;
108}
109
110
111int tls_server_key_exchange_allowed(tls_cipher cipher)
112{
113	const struct tls_cipher_suite *suite;
114
115	/* RFC 2246, Section 7.4.3 */
116	suite = tls_get_cipher_suite(cipher);
117	if (suite == NULL)
118		return 0;
119
120	switch (suite->key_exchange) {
121	case TLS_KEY_X_DHE_DSS:
122	case TLS_KEY_X_DHE_DSS_EXPORT:
123	case TLS_KEY_X_DHE_RSA:
124	case TLS_KEY_X_DHE_RSA_EXPORT:
125	case TLS_KEY_X_DH_anon_EXPORT:
126	case TLS_KEY_X_DH_anon:
127		return 1;
128	case TLS_KEY_X_RSA_EXPORT:
129		return 1 /* FIX: public key len > 512 bits */;
130	default:
131		return 0;
132	}
133}
134
135
136/**
137 * tls_parse_cert - Parse DER encoded X.509 certificate and get public key
138 * @buf: ASN.1 DER encoded certificate
139 * @len: Length of the buffer
140 * @pk: Buffer for returning the allocated public key
141 * Returns: 0 on success, -1 on failure
142 *
143 * This functions parses an ASN.1 DER encoded X.509 certificate and retrieves
144 * the public key from it. The caller is responsible for freeing the public key
145 * by calling crypto_public_key_free().
146 */
147int tls_parse_cert(const u8 *buf, size_t len, struct crypto_public_key **pk)
148{
149	struct x509_certificate *cert;
150
151	wpa_hexdump(MSG_MSGDUMP, "TLSv1: Parse ASN.1 DER certificate",
152		    buf, len);
153
154	*pk = crypto_public_key_from_cert(buf, len);
155	if (*pk)
156		return 0;
157
158	cert = x509_certificate_parse(buf, len);
159	if (cert == NULL) {
160		wpa_printf(MSG_DEBUG, "TLSv1: Failed to parse X.509 "
161			   "certificate");
162		return -1;
163	}
164
165	/* TODO
166	 * verify key usage (must allow encryption)
167	 *
168	 * All certificate profiles, key and cryptographic formats are
169	 * defined by the IETF PKIX working group [PKIX]. When a key
170	 * usage extension is present, the digitalSignature bit must be
171	 * set for the key to be eligible for signing, as described
172	 * above, and the keyEncipherment bit must be present to allow
173	 * encryption, as described above. The keyAgreement bit must be
174	 * set on Diffie-Hellman certificates. (PKIX: RFC 3280)
175	 */
176
177	*pk = crypto_public_key_import(cert->public_key, cert->public_key_len);
178	x509_certificate_free(cert);
179
180	if (*pk == NULL) {
181		wpa_printf(MSG_ERROR, "TLSv1: Failed to import "
182			   "server public key");
183		return -1;
184	}
185
186	return 0;
187}
188
189
190int tls_verify_hash_init(struct tls_verify_hash *verify)
191{
192	tls_verify_hash_free(verify);
193	verify->md5_client = crypto_hash_init(CRYPTO_HASH_ALG_MD5, NULL, 0);
194	verify->md5_server = crypto_hash_init(CRYPTO_HASH_ALG_MD5, NULL, 0);
195	verify->md5_cert = crypto_hash_init(CRYPTO_HASH_ALG_MD5, NULL, 0);
196	verify->sha1_client = crypto_hash_init(CRYPTO_HASH_ALG_SHA1, NULL, 0);
197	verify->sha1_server = crypto_hash_init(CRYPTO_HASH_ALG_SHA1, NULL, 0);
198	verify->sha1_cert = crypto_hash_init(CRYPTO_HASH_ALG_SHA1, NULL, 0);
199	if (verify->md5_client == NULL || verify->md5_server == NULL ||
200	    verify->md5_cert == NULL || verify->sha1_client == NULL ||
201	    verify->sha1_server == NULL || verify->sha1_cert == NULL) {
202		tls_verify_hash_free(verify);
203		return -1;
204	}
205	return 0;
206}
207
208
209void tls_verify_hash_add(struct tls_verify_hash *verify, const u8 *buf,
210			 size_t len)
211{
212	if (verify->md5_client && verify->sha1_client) {
213		crypto_hash_update(verify->md5_client, buf, len);
214		crypto_hash_update(verify->sha1_client, buf, len);
215	}
216	if (verify->md5_server && verify->sha1_server) {
217		crypto_hash_update(verify->md5_server, buf, len);
218		crypto_hash_update(verify->sha1_server, buf, len);
219	}
220	if (verify->md5_cert && verify->sha1_cert) {
221		crypto_hash_update(verify->md5_cert, buf, len);
222		crypto_hash_update(verify->sha1_cert, buf, len);
223	}
224}
225
226
227void tls_verify_hash_free(struct tls_verify_hash *verify)
228{
229	crypto_hash_finish(verify->md5_client, NULL, NULL);
230	crypto_hash_finish(verify->md5_server, NULL, NULL);
231	crypto_hash_finish(verify->md5_cert, NULL, NULL);
232	crypto_hash_finish(verify->sha1_client, NULL, NULL);
233	crypto_hash_finish(verify->sha1_server, NULL, NULL);
234	crypto_hash_finish(verify->sha1_cert, NULL, NULL);
235	verify->md5_client = NULL;
236	verify->md5_server = NULL;
237	verify->md5_cert = NULL;
238	verify->sha1_client = NULL;
239	verify->sha1_server = NULL;
240	verify->sha1_cert = NULL;
241}
242