1 /* $OpenBSD: tls_conninfo.c,v 1.22 2021/01/05 15:57:38 tb Exp $ */
2 /*
3  * Copyright (c) 2015 Joel Sing <jsing@openbsd.org>
4  * Copyright (c) 2015 Bob Beck <beck@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <stdio.h>
20 
21 #include <openssl/x509.h>
22 
23 #include <tls.h>
24 #include "tls_internal.h"
25 
26 int ASN1_time_tm_clamp_notafter(struct tm *tm);
27 
28 int
29 tls_hex_string(const unsigned char *in, size_t inlen, char **out,
30     size_t *outlen)
31 {
32 	static const char hex[] = "0123456789abcdef";
33 	size_t i, len;
34 	char *p;
35 
36 	if (outlen != NULL)
37 		*outlen = 0;
38 
39 	if (inlen >= SIZE_MAX)
40 		return (-1);
41 	if ((*out = reallocarray(NULL, inlen + 1, 2)) == NULL)
42 		return (-1);
43 
44 	p = *out;
45 	len = 0;
46 	for (i = 0; i < inlen; i++) {
47 		p[len++] = hex[(in[i] >> 4) & 0x0f];
48 		p[len++] = hex[in[i] & 0x0f];
49 	}
50 	p[len++] = 0;
51 
52 	if (outlen != NULL)
53 		*outlen = len;
54 
55 	return (0);
56 }
57 
58 static int
59 tls_get_peer_cert_hash(struct tls *ctx, char **hash)
60 {
61 	*hash = NULL;
62 	if (ctx->ssl_peer_cert == NULL)
63 		return (0);
64 
65 	if (tls_cert_hash(ctx->ssl_peer_cert, hash) == -1) {
66 		tls_set_errorx(ctx, "unable to compute peer certificate hash - out of memory");
67 		*hash = NULL;
68 		return -1;
69 	}
70 	return 0;
71 }
72 
73 static int
74 tls_get_peer_cert_issuer(struct tls *ctx,  char **issuer)
75 {
76 	X509_NAME *name = NULL;
77 
78 	*issuer = NULL;
79 	if (ctx->ssl_peer_cert == NULL)
80 		return (-1);
81 	if ((name = X509_get_issuer_name(ctx->ssl_peer_cert)) == NULL)
82 		return (-1);
83 	*issuer = X509_NAME_oneline(name, 0, 0);
84 	if (*issuer == NULL)
85 		return (-1);
86 	return (0);
87 }
88 
89 static int
90 tls_get_peer_cert_subject(struct tls *ctx, char **subject)
91 {
92 	X509_NAME *name = NULL;
93 
94 	*subject = NULL;
95 	if (ctx->ssl_peer_cert == NULL)
96 		return (-1);
97 	if ((name = X509_get_subject_name(ctx->ssl_peer_cert)) == NULL)
98 		return (-1);
99 	*subject = X509_NAME_oneline(name, 0, 0);
100 	if (*subject == NULL)
101 		return (-1);
102 	return (0);
103 }
104 
105 static int
106 tls_get_peer_cert_times(struct tls *ctx, time_t *notbefore,
107     time_t *notafter)
108 {
109 	struct tm before_tm, after_tm;
110 	ASN1_TIME *before, *after;
111 
112 	if (ctx->ssl_peer_cert == NULL)
113 		return (-1);
114 
115 	if ((before = X509_get_notBefore(ctx->ssl_peer_cert)) == NULL)
116 		goto err;
117 	if ((after = X509_get_notAfter(ctx->ssl_peer_cert)) == NULL)
118 		goto err;
119 	if (ASN1_time_parse(before->data, before->length, &before_tm, 0) == -1)
120 		goto err;
121 	if (ASN1_time_parse(after->data, after->length, &after_tm, 0) == -1)
122 		goto err;
123 	if (!ASN1_time_tm_clamp_notafter(&after_tm))
124 		goto err;
125 	if ((*notbefore = timegm(&before_tm)) == -1)
126 		goto err;
127 	if ((*notafter = timegm(&after_tm)) == -1)
128 		goto err;
129 
130 	return (0);
131 
132  err:
133 	return (-1);
134 }
135 
136 static int
137 tls_get_peer_cert_info(struct tls *ctx)
138 {
139 	if (ctx->ssl_peer_cert == NULL)
140 		return (0);
141 
142 	if (tls_get_peer_cert_hash(ctx, &ctx->conninfo->hash) == -1)
143 		goto err;
144 	if (tls_get_peer_cert_subject(ctx, &ctx->conninfo->subject) == -1)
145 		goto err;
146 	if (tls_get_peer_cert_issuer(ctx, &ctx->conninfo->issuer) == -1)
147 		goto err;
148 	if (tls_get_peer_cert_times(ctx, &ctx->conninfo->notbefore,
149 	    &ctx->conninfo->notafter) == -1)
150 		goto err;
151 
152 	return (0);
153 
154  err:
155 	return (-1);
156 }
157 
158 static int
159 tls_conninfo_alpn_proto(struct tls *ctx)
160 {
161 	const unsigned char *p;
162 	unsigned int len;
163 
164 	free(ctx->conninfo->alpn);
165 	ctx->conninfo->alpn = NULL;
166 
167 	SSL_get0_alpn_selected(ctx->ssl_conn, &p, &len);
168 	if (len > 0) {
169 		if ((ctx->conninfo->alpn = malloc(len + 1)) == NULL)
170 			return (-1);
171 		memcpy(ctx->conninfo->alpn, p, len);
172 		ctx->conninfo->alpn[len] = '\0';
173 	}
174 
175 	return (0);
176 }
177 
178 static int
179 tls_conninfo_cert_pem(struct tls *ctx)
180 {
181 	int i, rv = -1;
182 	BIO *membio = NULL;
183 	BUF_MEM *bptr = NULL;
184 
185 	if (ctx->ssl_peer_cert == NULL)
186 		return 0;
187 	if ((membio = BIO_new(BIO_s_mem()))== NULL)
188 		goto err;
189 
190 	/*
191 	 * We have to write the peer cert out separately, because
192 	 * the certificate chain may or may not contain it.
193 	 */
194 	if (!PEM_write_bio_X509(membio, ctx->ssl_peer_cert))
195 		goto err;
196 	for (i = 0; i < sk_X509_num(ctx->ssl_peer_chain); i++) {
197 		X509 *chaincert = sk_X509_value(ctx->ssl_peer_chain, i);
198 		if (chaincert != ctx->ssl_peer_cert &&
199 		    !PEM_write_bio_X509(membio, chaincert))
200 			goto err;
201 	}
202 
203 	BIO_get_mem_ptr(membio, &bptr);
204 	free(ctx->conninfo->peer_cert);
205 	ctx->conninfo->peer_cert_len = 0;
206 	if ((ctx->conninfo->peer_cert = malloc(bptr->length)) == NULL)
207 		goto err;
208 	ctx->conninfo->peer_cert_len = bptr->length;
209 	memcpy(ctx->conninfo->peer_cert, bptr->data,
210 	    ctx->conninfo->peer_cert_len);
211 
212 	/* BIO_free() will kill BUF_MEM - because we have not set BIO_NOCLOSE */
213 	rv = 0;
214  err:
215 	BIO_free(membio);
216 	return rv;
217 }
218 
219 static int
220 tls_conninfo_session(struct tls *ctx)
221 {
222 	ctx->conninfo->session_resumed = SSL_session_reused(ctx->ssl_conn);
223 
224 	return 0;
225 }
226 
227 int
228 tls_conninfo_populate(struct tls *ctx)
229 {
230 	const char *tmp;
231 
232 	tls_conninfo_free(ctx->conninfo);
233 
234 	if ((ctx->conninfo = calloc(1, sizeof(struct tls_conninfo))) == NULL) {
235 		tls_set_errorx(ctx, "out of memory");
236 		goto err;
237 	}
238 
239 	if (tls_conninfo_alpn_proto(ctx) == -1)
240 		goto err;
241 
242 	if ((tmp = SSL_get_cipher(ctx->ssl_conn)) == NULL)
243 		goto err;
244 	if ((ctx->conninfo->cipher = strdup(tmp)) == NULL)
245 		goto err;
246 	ctx->conninfo->cipher_strength = SSL_get_cipher_bits(ctx->ssl_conn, NULL);
247 
248 	if (ctx->servername != NULL) {
249 		if ((ctx->conninfo->servername =
250 		    strdup(ctx->servername)) == NULL)
251 			goto err;
252 	}
253 
254 	if ((tmp = SSL_get_version(ctx->ssl_conn)) == NULL)
255 		goto err;
256 	if ((ctx->conninfo->version = strdup(tmp)) == NULL)
257 		goto err;
258 
259 	if (tls_get_peer_cert_info(ctx) == -1)
260 		goto err;
261 
262 	if (tls_conninfo_cert_pem(ctx) == -1)
263 		goto err;
264 
265 	if (tls_conninfo_session(ctx) == -1)
266 		goto err;
267 
268 	return (0);
269 
270  err:
271 	tls_conninfo_free(ctx->conninfo);
272 	ctx->conninfo = NULL;
273 
274 	return (-1);
275 }
276 
277 void
278 tls_conninfo_free(struct tls_conninfo *conninfo)
279 {
280 	if (conninfo == NULL)
281 		return;
282 
283 	free(conninfo->alpn);
284 	free(conninfo->cipher);
285 	free(conninfo->servername);
286 	free(conninfo->version);
287 
288 	free(conninfo->hash);
289 	free(conninfo->issuer);
290 	free(conninfo->subject);
291 
292 	free(conninfo->peer_cert);
293 
294 	free(conninfo);
295 }
296 
297 const char *
298 tls_conn_alpn_selected(struct tls *ctx)
299 {
300 	if (ctx->conninfo == NULL)
301 		return (NULL);
302 	return (ctx->conninfo->alpn);
303 }
304 
305 const char *
306 tls_conn_cipher(struct tls *ctx)
307 {
308 	if (ctx->conninfo == NULL)
309 		return (NULL);
310 	return (ctx->conninfo->cipher);
311 }
312 
313 int
314 tls_conn_cipher_strength(struct tls *ctx)
315 {
316 	if (ctx->conninfo == NULL)
317 		return (0);
318 	return (ctx->conninfo->cipher_strength);
319 }
320 
321 const char *
322 tls_conn_servername(struct tls *ctx)
323 {
324 	if (ctx->conninfo == NULL)
325 		return (NULL);
326 	return (ctx->conninfo->servername);
327 }
328 
329 int
330 tls_conn_session_resumed(struct tls *ctx)
331 {
332 	if (ctx->conninfo == NULL)
333 		return (0);
334 	return (ctx->conninfo->session_resumed);
335 }
336 
337 const char *
338 tls_conn_version(struct tls *ctx)
339 {
340 	if (ctx->conninfo == NULL)
341 		return (NULL);
342 	return (ctx->conninfo->version);
343 }
344