1 /* $OpenBSD: tls_server.c,v 1.49 2023/05/14 07:26:25 op Exp $ */
3 * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 #include <sys/socket.h>
22 #include <arpa/inet.h>
26 #include <openssl/asn1.h>
27 #include <openssl/ec.h>
28 #include <openssl/err.h>
29 #include <openssl/ssl.h>
32 #include "tls_internal.h"
42 if ((ctx = tls_new()) == NULL)
45 ctx->flags |= TLS_SERVER;
51 tls_server_conn(struct tls *ctx)
55 if ((conn_ctx = tls_new()) == NULL)
58 conn_ctx->flags |= TLS_SERVER_CONN;
60 ctx->config->refcount++;
62 conn_ctx->config = ctx->config;
63 conn_ctx->keypair = ctx->config->keypair;
69 tls_server_alpn_cb(SSL *ssl, const unsigned char **out, unsigned char *outlen,
70 const unsigned char *in, unsigned int inlen, void *arg)
72 struct tls *ctx = arg;
74 if (SSL_select_next_proto((unsigned char**)out, outlen,
75 ctx->config->alpn, ctx->config->alpn_len, in, inlen) ==
76 OPENSSL_NPN_NEGOTIATED)
77 return (SSL_TLSEXT_ERR_OK);
79 return (SSL_TLSEXT_ERR_NOACK);
83 tls_servername_cb(SSL *ssl, int *al, void *arg)
85 struct tls *ctx = (struct tls *)arg;
86 struct tls_sni_ctx *sni_ctx;
87 union tls_addr addrbuf;
92 if ((conn_ctx = SSL_get_app_data(ssl)) == NULL)
95 if ((name = SSL_get_servername(ssl, TLSEXT_NAMETYPE_host_name)) ==
98 * The servername callback gets called even when there is no
99 * TLS servername extension provided by the client. Sigh!
101 return (SSL_TLSEXT_ERR_NOACK);
105 * Per RFC 6066 section 3: ensure that name is not an IP literal.
107 * While we should treat this as an error, a number of clients
108 * (Python, Ruby and Safari) are not RFC compliant. To avoid handshake
109 * failures, pretend that we did not receive the extension.
111 if (inet_pton(AF_INET, name, &addrbuf) == 1 ||
112 inet_pton(AF_INET6, name, &addrbuf) == 1)
113 return (SSL_TLSEXT_ERR_NOACK);
115 free(conn_ctx->servername);
116 if ((conn_ctx->servername = strdup(name)) == NULL)
119 /* Find appropriate SSL context for requested servername. */
120 for (sni_ctx = ctx->sni_ctx; sni_ctx != NULL; sni_ctx = sni_ctx->next) {
121 if (tls_check_name(ctx, sni_ctx->ssl_cert, name,
125 conn_ctx->keypair = sni_ctx->keypair;
126 SSL_set_SSL_CTX(conn_ctx->ssl_conn, sni_ctx->ssl_ctx);
127 return (SSL_TLSEXT_ERR_OK);
131 /* No match, use the existing context/certificate. */
132 return (SSL_TLSEXT_ERR_OK);
136 * There is no way to tell libssl that an internal failure occurred.
137 * The only option we have is to return a fatal alert.
139 *al = SSL_AD_INTERNAL_ERROR;
140 return (SSL_TLSEXT_ERR_ALERT_FATAL);
143 static struct tls_ticket_key *
144 tls_server_ticket_key(struct tls_config *config, unsigned char *keyname)
146 struct tls_ticket_key *key = NULL;
151 if (config->ticket_autorekey == 1) {
152 if (now - 3 * (config->session_lifetime / 4) >
153 config->ticket_keys[0].time) {
154 if (tls_config_ticket_autorekey(config) == -1)
158 for (i = 0; i < TLS_NUM_TICKETS; i++) {
159 struct tls_ticket_key *tk = &config->ticket_keys[i];
160 if (now - config->session_lifetime > tk->time)
162 if (keyname == NULL || timingsafe_memcmp(keyname,
163 tk->key_name, sizeof(tk->key_name)) == 0) {
172 tls_server_ticket_cb(SSL *ssl, unsigned char *keyname, unsigned char *iv,
173 EVP_CIPHER_CTX *ctx, HMAC_CTX *hctx, int mode)
175 struct tls_ticket_key *key;
178 if ((tls_ctx = SSL_get_app_data(ssl)) == NULL)
182 /* create new session */
183 key = tls_server_ticket_key(tls_ctx->config, NULL);
185 tls_set_errorx(tls_ctx, "no valid ticket key found");
189 memcpy(keyname, key->key_name, sizeof(key->key_name));
190 arc4random_buf(iv, EVP_MAX_IV_LENGTH);
191 if (!EVP_EncryptInit_ex(ctx, EVP_aes_256_cbc(), NULL,
193 tls_set_errorx(tls_ctx, "failed to init encrypt");
196 if (!HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
197 EVP_sha256(), NULL)) {
198 tls_set_errorx(tls_ctx, "failed to init hmac");
203 /* get key by name */
204 key = tls_server_ticket_key(tls_ctx->config, keyname);
208 if (!EVP_DecryptInit_ex(ctx, EVP_aes_256_cbc(), NULL,
210 tls_set_errorx(tls_ctx, "failed to init decrypt");
213 if (!HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
214 EVP_sha256(), NULL)) {
215 tls_set_errorx(tls_ctx, "failed to init hmac");
219 /* time to renew the ticket? is it the primary key? */
220 if (key != &tls_ctx->config->ticket_keys[0])
227 tls_configure_server_ssl(struct tls *ctx, SSL_CTX **ssl_ctx,
228 struct tls_keypair *keypair)
230 SSL_CTX_free(*ssl_ctx);
232 if ((*ssl_ctx = SSL_CTX_new(SSLv23_server_method())) == NULL) {
233 tls_set_errorx(ctx, "ssl context failure");
237 #ifdef SSL_OP_NO_CLIENT_RENEGOTIATION
238 SSL_CTX_set_options(*ssl_ctx, SSL_OP_NO_CLIENT_RENEGOTIATION);
241 if (SSL_CTX_set_tlsext_servername_callback(*ssl_ctx,
242 tls_servername_cb) != 1) {
243 tls_set_error(ctx, "failed to set servername callback");
246 if (SSL_CTX_set_tlsext_servername_arg(*ssl_ctx, ctx) != 1) {
247 tls_set_error(ctx, "failed to set servername callback arg");
251 if (tls_configure_ssl(ctx, *ssl_ctx) != 0)
253 if (tls_configure_ssl_keypair(ctx, *ssl_ctx, keypair, 1) != 0)
255 if (ctx->config->verify_client != 0) {
256 int verify = SSL_VERIFY_PEER;
257 if (ctx->config->verify_client == 1)
258 verify |= SSL_VERIFY_FAIL_IF_NO_PEER_CERT;
259 if (tls_configure_ssl_verify(ctx, *ssl_ctx, verify) == -1)
263 if (ctx->config->alpn != NULL)
264 SSL_CTX_set_alpn_select_cb(*ssl_ctx, tls_server_alpn_cb,
267 if (ctx->config->dheparams == -1)
268 SSL_CTX_set_dh_auto(*ssl_ctx, 1);
269 else if (ctx->config->dheparams == 1024)
270 SSL_CTX_set_dh_auto(*ssl_ctx, 2);
272 if (ctx->config->ecdhecurves != NULL) {
273 SSL_CTX_set_ecdh_auto(*ssl_ctx, 1);
274 if (SSL_CTX_set1_groups(*ssl_ctx, ctx->config->ecdhecurves,
275 ctx->config->ecdhecurves_len) != 1) {
276 tls_set_errorx(ctx, "failed to set ecdhe curves");
281 if (ctx->config->ciphers_server == 1)
282 SSL_CTX_set_options(*ssl_ctx, SSL_OP_CIPHER_SERVER_PREFERENCE);
284 if (SSL_CTX_set_tlsext_status_cb(*ssl_ctx, tls_ocsp_stapling_cb) != 1) {
285 tls_set_errorx(ctx, "failed to add OCSP stapling callback");
289 if (ctx->config->session_lifetime > 0) {
290 /* set the session lifetime and enable tickets */
291 SSL_CTX_set_timeout(*ssl_ctx, ctx->config->session_lifetime);
292 SSL_CTX_clear_options(*ssl_ctx, SSL_OP_NO_TICKET);
293 if (!SSL_CTX_set_tlsext_ticket_key_cb(*ssl_ctx,
294 tls_server_ticket_cb)) {
296 "failed to set the TLS ticket callback");
301 if (SSL_CTX_set_session_id_context(*ssl_ctx, ctx->config->session_id,
302 sizeof(ctx->config->session_id)) != 1) {
303 tls_set_error(ctx, "failed to set session id context");
310 SSL_CTX_free(*ssl_ctx);
317 tls_configure_server_sni(struct tls *ctx)
319 struct tls_sni_ctx **sni_ctx;
320 struct tls_keypair *kp;
322 if (ctx->config->keypair->next == NULL)
325 /* Set up additional SSL contexts for SNI. */
326 sni_ctx = &ctx->sni_ctx;
327 for (kp = ctx->config->keypair->next; kp != NULL; kp = kp->next) {
328 if ((*sni_ctx = tls_sni_ctx_new()) == NULL) {
329 tls_set_errorx(ctx, "out of memory");
332 (*sni_ctx)->keypair = kp;
333 if (tls_configure_server_ssl(ctx, &(*sni_ctx)->ssl_ctx, kp) == -1)
335 if (tls_keypair_load_cert(kp, &ctx->error,
336 &(*sni_ctx)->ssl_cert) == -1)
338 sni_ctx = &(*sni_ctx)->next;
348 tls_configure_server(struct tls *ctx)
350 if (tls_configure_server_ssl(ctx, &ctx->ssl_ctx,
351 ctx->config->keypair) == -1)
353 if (tls_configure_server_sni(ctx) == -1)
363 tls_accept_common(struct tls *ctx)
365 struct tls *conn_ctx = NULL;
367 if ((ctx->flags & TLS_SERVER) == 0) {
368 tls_set_errorx(ctx, "not a server context");
372 if ((conn_ctx = tls_server_conn(ctx)) == NULL) {
373 tls_set_errorx(ctx, "connection context failure");
377 if ((conn_ctx->ssl_conn = SSL_new(ctx->ssl_ctx)) == NULL) {
378 tls_set_errorx(ctx, "ssl failure");
382 if (SSL_set_app_data(conn_ctx->ssl_conn, conn_ctx) != 1) {
383 tls_set_errorx(ctx, "ssl application data failure");
396 tls_accept_socket(struct tls *ctx, struct tls **cctx, int s)
398 return (tls_accept_fds(ctx, cctx, s, s));
402 tls_accept_fds(struct tls *ctx, struct tls **cctx, int fd_read, int fd_write)
404 struct tls *conn_ctx;
406 if ((conn_ctx = tls_accept_common(ctx)) == NULL)
409 if (SSL_set_rfd(conn_ctx->ssl_conn, fd_read) != 1 ||
410 SSL_set_wfd(conn_ctx->ssl_conn, fd_write) != 1) {
411 tls_set_errorx(ctx, "ssl file descriptor failure");
426 tls_accept_cbs(struct tls *ctx, struct tls **cctx,
427 tls_read_cb read_cb, tls_write_cb write_cb, void *cb_arg)
429 struct tls *conn_ctx;
431 if ((conn_ctx = tls_accept_common(ctx)) == NULL)
434 if (tls_set_cbs(conn_ctx, read_cb, write_cb, cb_arg) != 0)
448 tls_handshake_server(struct tls *ctx)
453 if ((ctx->flags & TLS_SERVER_CONN) == 0) {
454 tls_set_errorx(ctx, "not a server connection context");
458 ctx->state |= TLS_SSL_NEEDS_SHUTDOWN;
461 if ((ssl_ret = SSL_accept(ctx->ssl_conn)) != 1) {
462 rv = tls_ssl_error(ctx, ctx->ssl_conn, ssl_ret, "handshake");
466 ctx->state |= TLS_HANDSHAKE_COMPLETE;