1 /*
2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include "inner.h"
26 
27 static int
28 sr_choose(const br_ssl_server_policy_class **pctx,
29 	const br_ssl_server_context *cc,
30 	br_ssl_server_choices *choices)
31 {
32 	br_ssl_server_policy_rsa_context *pc;
33 	const br_suite_translated *st;
34 	size_t u, st_num;
35 	unsigned hash_id;
36 	int fh;
37 
38 	pc = (br_ssl_server_policy_rsa_context *)pctx;
39 	st = br_ssl_server_get_client_suites(cc, &st_num);
40 	if (cc->eng.session.version < BR_TLS12) {
41 		hash_id = 0;
42 		fh = 1;
43 	} else {
44 		hash_id = br_ssl_choose_hash(
45 			br_ssl_server_get_client_hashes(cc));
46 		fh = (hash_id != 0);
47 	}
48 	choices->chain = pc->chain;
49 	choices->chain_len = pc->chain_len;
50 	for (u = 0; u < st_num; u ++) {
51 		unsigned tt;
52 
53 		tt = st[u][1];
54 		switch (tt >> 12) {
55 		case BR_SSLKEYX_RSA:
56 			if ((pc->allowed_usages & BR_KEYTYPE_KEYX) != 0) {
57 				choices->cipher_suite = st[u][0];
58 				return 1;
59 			}
60 			break;
61 		case BR_SSLKEYX_ECDHE_RSA:
62 			if ((pc->allowed_usages & BR_KEYTYPE_SIGN) != 0 && fh) {
63 				choices->cipher_suite = st[u][0];
64 				choices->algo_id = hash_id + 0xFF00;
65 				return 1;
66 			}
67 			break;
68 		}
69 	}
70 	return 0;
71 }
72 
73 static uint32_t
74 sr_do_keyx(const br_ssl_server_policy_class **pctx,
75 	unsigned char *data, size_t *len)
76 {
77 	br_ssl_server_policy_rsa_context *pc;
78 
79 	pc = (br_ssl_server_policy_rsa_context *)pctx;
80 	return br_rsa_ssl_decrypt(pc->irsacore, pc->sk, data, *len);
81 }
82 
83 /*
84  * OID for hash functions in RSA signatures.
85  */
86 static const unsigned char HASH_OID_SHA1[] = {
87 	0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A
88 };
89 
90 static const unsigned char HASH_OID_SHA224[] = {
91 	0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04
92 };
93 
94 static const unsigned char HASH_OID_SHA256[] = {
95 	0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01
96 };
97 
98 static const unsigned char HASH_OID_SHA384[] = {
99 	0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02
100 };
101 
102 static const unsigned char HASH_OID_SHA512[] = {
103 	0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03
104 };
105 
106 static const unsigned char *HASH_OID[] = {
107 	HASH_OID_SHA1,
108 	HASH_OID_SHA224,
109 	HASH_OID_SHA256,
110 	HASH_OID_SHA384,
111 	HASH_OID_SHA512
112 };
113 
114 static size_t
115 sr_do_sign(const br_ssl_server_policy_class **pctx,
116 	unsigned algo_id, unsigned char *data, size_t hv_len, size_t len)
117 {
118 	br_ssl_server_policy_rsa_context *pc;
119 	unsigned char hv[64];
120 	size_t sig_len;
121 	const unsigned char *hash_oid;
122 
123 	pc = (br_ssl_server_policy_rsa_context *)pctx;
124 	memcpy(hv, data, hv_len);
125 	algo_id &= 0xFF;
126 	if (algo_id == 0) {
127 		hash_oid = NULL;
128 	} else if (algo_id >= 2 && algo_id <= 6) {
129 		hash_oid = HASH_OID[algo_id - 2];
130 	} else {
131 		return 0;
132 	}
133 	sig_len = (pc->sk->n_bitlen + 7) >> 3;
134 	if (len < sig_len) {
135 		return 0;
136 	}
137 	return pc->irsasign(hash_oid, hv, hv_len, pc->sk, data) ? sig_len : 0;
138 }
139 
140 static const br_ssl_server_policy_class sr_policy_vtable = {
141 	sizeof(br_ssl_server_policy_rsa_context),
142 	sr_choose,
143 	sr_do_keyx,
144 	sr_do_sign
145 };
146 
147 /* see bearssl_ssl.h */
148 void
149 br_ssl_server_set_single_rsa(br_ssl_server_context *cc,
150 	const br_x509_certificate *chain, size_t chain_len,
151 	const br_rsa_private_key *sk, unsigned allowed_usages,
152 	br_rsa_private irsacore, br_rsa_pkcs1_sign irsasign)
153 {
154 	cc->chain_handler.single_rsa.vtable = &sr_policy_vtable;
155 	cc->chain_handler.single_rsa.chain = chain;
156 	cc->chain_handler.single_rsa.chain_len = chain_len;
157 	cc->chain_handler.single_rsa.sk = sk;
158 	cc->chain_handler.single_rsa.allowed_usages = allowed_usages;
159 	cc->chain_handler.single_rsa.irsacore = irsacore;
160 	cc->chain_handler.single_rsa.irsasign = irsasign;
161 	cc->policy_vtable = &cc->chain_handler.single_rsa.vtable;
162 }
163