2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 /* ====================================================================
11 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
12 * ECC cipher suite support in OpenSSL originally developed by
13 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
19 #include "../ssl_locl.h"
20 #include "statem_locl.h"
21 #include <openssl/buffer.h>
22 #include <openssl/objects.h>
23 #include <openssl/evp.h>
24 #include <openssl/x509.h>
27 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
28 * SSL3_RT_CHANGE_CIPHER_SPEC)
30 int ssl3_do_write(SSL *s, int type)
35 ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
36 s->init_num, &written);
39 if (type == SSL3_RT_HANDSHAKE)
41 * should not be done for 'Hello Request's, but in that case we'll
42 * ignore the result anyway
44 if (!ssl3_finish_mac(s,
45 (unsigned char *)&s->init_buf->data[s->init_off],
49 if (written == s->init_num) {
51 s->msg_callback(1, s->version, type, s->init_buf->data,
52 (size_t)(s->init_off + s->init_num), s,
56 s->init_off += written;
57 s->init_num -= written;
61 int tls_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
65 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
66 || !WPACKET_get_length(pkt, &msglen)
69 s->init_num = (int)msglen;
75 int tls_construct_finished(SSL *s, WPACKET *pkt)
82 sender = s->method->ssl3_enc->server_finished_label;
83 slen = s->method->ssl3_enc->server_finished_label_len;
85 sender = s->method->ssl3_enc->client_finished_label;
86 slen = s->method->ssl3_enc->client_finished_label_len;
89 finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
91 s->s3->tmp.finish_md);
92 if (finish_md_len == 0) {
93 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
97 s->s3->tmp.finish_md_len = finish_md_len;
99 if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, finish_md_len)) {
100 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
105 * Copy the finished so we can use it for renegotiation checks
108 OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
109 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md,
111 s->s3->previous_client_finished_len = finish_md_len;
113 OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
114 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md,
116 s->s3->previous_server_finished_len = finish_md_len;
121 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
125 #ifndef OPENSSL_NO_NEXTPROTONEG
127 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
130 static void ssl3_take_mac(SSL *s)
135 * If no new cipher setup return immediately: other functions will set
136 * the appropriate error.
138 if (s->s3->tmp.new_cipher == NULL)
141 sender = s->method->ssl3_enc->server_finished_label;
142 slen = s->method->ssl3_enc->server_finished_label_len;
144 sender = s->method->ssl3_enc->client_finished_label;
145 slen = s->method->ssl3_enc->client_finished_label_len;
148 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
151 s->s3->tmp.peer_finish_md);
155 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
160 remain = PACKET_remaining(pkt);
162 * 'Change Cipher Spec' is just a single byte, which should already have
163 * been consumed by ssl_get_message() so there should be no bytes left,
164 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
166 if (SSL_IS_DTLS(s)) {
167 if ((s->version == DTLS1_BAD_VER
168 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
169 || (s->version != DTLS1_BAD_VER
170 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
171 al = SSL_AD_ILLEGAL_PARAMETER;
172 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
173 SSL_R_BAD_CHANGE_CIPHER_SPEC);
178 al = SSL_AD_ILLEGAL_PARAMETER;
179 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
180 SSL_R_BAD_CHANGE_CIPHER_SPEC);
185 /* Check we have a cipher to change to */
186 if (s->s3->tmp.new_cipher == NULL) {
187 al = SSL_AD_UNEXPECTED_MESSAGE;
188 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
192 s->s3->change_cipher_spec = 1;
193 if (!ssl3_do_change_cipher_spec(s)) {
194 al = SSL_AD_INTERNAL_ERROR;
195 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
199 if (SSL_IS_DTLS(s)) {
200 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
202 if (s->version == DTLS1_BAD_VER)
203 s->d1->handshake_read_seq++;
205 #ifndef OPENSSL_NO_SCTP
207 * Remember that a CCS has been received, so that an old key of
208 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
211 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
215 return MSG_PROCESS_CONTINUE_READING;
217 ssl3_send_alert(s, SSL3_AL_FATAL, al);
218 ossl_statem_set_error(s);
219 return MSG_PROCESS_ERROR;
222 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
224 int al = SSL_AD_INTERNAL_ERROR;
227 /* If this occurs, we have missed a message */
228 if (!SSL_IS_TLS13(s) && !s->s3->change_cipher_spec) {
229 al = SSL_AD_UNEXPECTED_MESSAGE;
230 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
233 s->s3->change_cipher_spec = 0;
235 md_len = s->s3->tmp.peer_finish_md_len;
237 if (md_len != PACKET_remaining(pkt)) {
238 al = SSL_AD_DECODE_ERROR;
239 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
243 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md,
245 al = SSL_AD_DECRYPT_ERROR;
246 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
251 * Copy the finished so we can use it for renegotiation checks
254 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
255 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md,
257 s->s3->previous_client_finished_len = md_len;
259 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
260 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md,
262 s->s3->previous_server_finished_len = md_len;
266 * In TLS1.3 we also have to change cipher state and do any final processing
267 * of the initial server flight (if we are a client)
269 if (SSL_IS_TLS13(s)) {
271 if (!s->method->ssl3_enc->change_cipher_state(s,
272 SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_SERVER_READ)) {
273 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
277 if (!s->method->ssl3_enc->generate_master_secret(s,
278 s->session->master_key, s->handshake_secret, 0,
279 &s->session->master_key_length)) {
280 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
283 if (!s->method->ssl3_enc->change_cipher_state(s,
284 SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_READ)) {
285 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
288 if (!tls_process_initial_server_flight(s, &al))
293 return MSG_PROCESS_FINISHED_READING;
295 ssl3_send_alert(s, SSL3_AL_FATAL, al);
296 ossl_statem_set_error(s);
297 return MSG_PROCESS_ERROR;
300 int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
302 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) {
303 SSLerr(SSL_F_TLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
304 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
311 unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk)
313 if (!WPACKET_start_sub_packet_u24(pkt)
314 || !ssl_add_cert_chain(s, pkt, cpk)
315 || !WPACKET_close(pkt)) {
316 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
322 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
324 void (*cb) (const SSL *ssl, int type, int val) = NULL;
326 #ifndef OPENSSL_NO_SCTP
327 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
329 ret = dtls_wait_for_dry(s);
330 if (ret != WORK_FINISHED_CONTINUE)
335 /* clean a few things up */
336 ssl3_cleanup_key_block(s);
338 if (!SSL_IS_DTLS(s)) {
340 * We don't do this in DTLS because we may still need the init_buf
341 * in case there are any unexpected retransmits
343 BUF_MEM_free(s->init_buf);
347 ssl_free_wbio_buffer(s);
351 if (!s->server || s->renegotiate == 2) {
352 /* skipped if we just sent a HelloRequest */
357 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
359 s->ctx->stats.sess_accept_good++;
360 s->handshake_func = ossl_statem_accept;
362 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
364 s->ctx->stats.sess_hit++;
366 s->handshake_func = ossl_statem_connect;
367 s->ctx->stats.sess_connect_good++;
370 if (s->info_callback != NULL)
371 cb = s->info_callback;
372 else if (s->ctx->info_callback != NULL)
373 cb = s->ctx->info_callback;
376 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
378 if (SSL_IS_DTLS(s)) {
379 /* done with handshaking */
380 s->d1->handshake_read_seq = 0;
381 s->d1->handshake_write_seq = 0;
382 s->d1->next_handshake_write_seq = 0;
383 dtls1_clear_received_buffer(s);
387 return WORK_FINISHED_STOP;
390 int tls_get_message_header(SSL *s, int *mt)
392 /* s->init_num < SSL3_HM_HEADER_LENGTH */
393 int skip_message, i, recvd_type, al;
397 p = (unsigned char *)s->init_buf->data;
400 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
401 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
403 SSL3_HM_HEADER_LENGTH - s->init_num,
406 s->rwstate = SSL_READING;
409 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
411 * A ChangeCipherSpec must be a single byte and may not occur
412 * in the middle of a handshake message.
414 if (s->init_num != 0 || readbytes != 1 || p[0] != SSL3_MT_CCS) {
415 al = SSL_AD_UNEXPECTED_MESSAGE;
416 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
417 SSL_R_BAD_CHANGE_CIPHER_SPEC);
420 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
421 s->init_num = readbytes - 1;
422 s->init_msg = s->init_buf->data;
423 s->s3->tmp.message_size = readbytes;
425 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
426 al = SSL_AD_UNEXPECTED_MESSAGE;
427 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
430 s->init_num += readbytes;
435 if (p[0] == SSL3_MT_HELLO_REQUEST)
437 * The server may always send 'Hello Request' messages --
438 * we are doing a handshake anyway now, so ignore them if
439 * their format is correct. Does not count for 'Finished'
442 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
447 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
448 p, SSL3_HM_HEADER_LENGTH, s,
449 s->msg_callback_arg);
451 } while (skip_message);
452 /* s->init_num == SSL3_HM_HEADER_LENGTH */
455 s->s3->tmp.message_type = *(p++);
457 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
459 * Only happens with SSLv3+ in an SSLv2 backward compatible
462 * Total message size is the remaining record bytes to read
463 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
465 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
466 + SSL3_HM_HEADER_LENGTH;
467 s->s3->tmp.message_size = l;
469 s->init_msg = s->init_buf->data;
470 s->init_num = SSL3_HM_HEADER_LENGTH;
473 /* BUF_MEM_grow takes an 'int' parameter */
474 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
475 al = SSL_AD_ILLEGAL_PARAMETER;
476 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
479 s->s3->tmp.message_size = l;
481 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
487 ssl3_send_alert(s, SSL3_AL_FATAL, al);
491 int tls_get_message_body(SSL *s, size_t *len)
497 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
498 /* We've already read everything in */
499 *len = (unsigned long)s->init_num;
504 n = s->s3->tmp.message_size - s->init_num;
506 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
507 &p[s->init_num], n, 0, &readbytes);
509 s->rwstate = SSL_READING;
513 s->init_num += readbytes;
517 #ifndef OPENSSL_NO_NEXTPROTONEG
519 * If receiving Finished, record MAC of prior handshake messages for
520 * Finished verification.
522 if (*s->init_buf->data == SSL3_MT_FINISHED)
526 /* Feed this message into MAC computation. */
527 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
528 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
530 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
531 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
536 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
537 (size_t)s->init_num, s, s->msg_callback_arg);
539 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
540 s->init_num + SSL3_HM_HEADER_LENGTH)) {
541 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
542 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
547 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
548 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
549 s->msg_callback_arg);
556 int ssl_cert_type(const X509 *x, const EVP_PKEY *pk)
558 if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL)
561 switch (EVP_PKEY_id(pk)) {
565 return SSL_PKEY_RSA_ENC;
567 return SSL_PKEY_DSA_SIGN;
568 #ifndef OPENSSL_NO_EC
572 #ifndef OPENSSL_NO_GOST
573 case NID_id_GostR3410_2001:
574 return SSL_PKEY_GOST01;
575 case NID_id_GostR3410_2012_256:
576 return SSL_PKEY_GOST12_256;
577 case NID_id_GostR3410_2012_512:
578 return SSL_PKEY_GOST12_512;
583 int ssl_verify_alarm_type(long type)
588 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
589 case X509_V_ERR_UNABLE_TO_GET_CRL:
590 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
591 al = SSL_AD_UNKNOWN_CA;
593 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
594 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
595 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
596 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
597 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
598 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
599 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
600 case X509_V_ERR_CERT_NOT_YET_VALID:
601 case X509_V_ERR_CRL_NOT_YET_VALID:
602 case X509_V_ERR_CERT_UNTRUSTED:
603 case X509_V_ERR_CERT_REJECTED:
604 case X509_V_ERR_HOSTNAME_MISMATCH:
605 case X509_V_ERR_EMAIL_MISMATCH:
606 case X509_V_ERR_IP_ADDRESS_MISMATCH:
607 case X509_V_ERR_DANE_NO_MATCH:
608 case X509_V_ERR_EE_KEY_TOO_SMALL:
609 case X509_V_ERR_CA_KEY_TOO_SMALL:
610 case X509_V_ERR_CA_MD_TOO_WEAK:
611 al = SSL_AD_BAD_CERTIFICATE;
613 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
614 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
615 al = SSL_AD_DECRYPT_ERROR;
617 case X509_V_ERR_CERT_HAS_EXPIRED:
618 case X509_V_ERR_CRL_HAS_EXPIRED:
619 al = SSL_AD_CERTIFICATE_EXPIRED;
621 case X509_V_ERR_CERT_REVOKED:
622 al = SSL_AD_CERTIFICATE_REVOKED;
624 case X509_V_ERR_UNSPECIFIED:
625 case X509_V_ERR_OUT_OF_MEM:
626 case X509_V_ERR_INVALID_CALL:
627 case X509_V_ERR_STORE_LOOKUP:
628 al = SSL_AD_INTERNAL_ERROR;
630 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
631 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
632 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
633 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
634 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
635 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
636 case X509_V_ERR_INVALID_CA:
637 al = SSL_AD_UNKNOWN_CA;
639 case X509_V_ERR_APPLICATION_VERIFICATION:
640 al = SSL_AD_HANDSHAKE_FAILURE;
642 case X509_V_ERR_INVALID_PURPOSE:
643 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
646 al = SSL_AD_CERTIFICATE_UNKNOWN;
652 int ssl_allow_compression(SSL *s)
654 if (s->options & SSL_OP_NO_COMPRESSION)
656 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
659 static int version_cmp(const SSL *s, int a, int b)
661 int dtls = SSL_IS_DTLS(s);
666 return a < b ? -1 : 1;
667 return DTLS_VERSION_LT(a, b) ? -1 : 1;
672 const SSL_METHOD *(*cmeth) (void);
673 const SSL_METHOD *(*smeth) (void);
676 #if TLS_MAX_VERSION != TLS1_3_VERSION
677 # error Code needs update for TLS_method() support beyond TLS1_3_VERSION.
680 static const version_info tls_version_table[] = {
681 #ifndef OPENSSL_NO_TLS1_3
682 {TLS1_3_VERSION, tlsv1_3_client_method, tlsv1_3_server_method},
684 {TLS1_3_VERSION, NULL, NULL},
686 #ifndef OPENSSL_NO_TLS1_2
687 {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
689 {TLS1_2_VERSION, NULL, NULL},
691 #ifndef OPENSSL_NO_TLS1_1
692 {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
694 {TLS1_1_VERSION, NULL, NULL},
696 #ifndef OPENSSL_NO_TLS1
697 {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
699 {TLS1_VERSION, NULL, NULL},
701 #ifndef OPENSSL_NO_SSL3
702 {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
704 {SSL3_VERSION, NULL, NULL},
709 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
710 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
713 static const version_info dtls_version_table[] = {
714 #ifndef OPENSSL_NO_DTLS1_2
715 {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
717 {DTLS1_2_VERSION, NULL, NULL},
719 #ifndef OPENSSL_NO_DTLS1
720 {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
721 {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
723 {DTLS1_VERSION, NULL, NULL},
724 {DTLS1_BAD_VER, NULL, NULL},
730 * ssl_method_error - Check whether an SSL_METHOD is enabled.
732 * @s: The SSL handle for the candidate method
733 * @method: the intended method.
735 * Returns 0 on success, or an SSL error reason on failure.
737 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
739 int version = method->version;
741 if ((s->min_proto_version != 0 &&
742 version_cmp(s, version, s->min_proto_version) < 0) ||
743 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
744 return SSL_R_VERSION_TOO_LOW;
746 if (s->max_proto_version != 0 &&
747 version_cmp(s, version, s->max_proto_version) > 0)
748 return SSL_R_VERSION_TOO_HIGH;
750 if ((s->options & method->mask) != 0)
751 return SSL_R_UNSUPPORTED_PROTOCOL;
752 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
753 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
754 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
755 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
761 * ssl_version_supported - Check that the specified `version` is supported by
764 * @s: The SSL handle for the candidate method
765 * @version: Protocol version to test against
767 * Returns 1 when supported, otherwise 0
769 int ssl_version_supported(const SSL *s, int version)
771 const version_info *vent;
772 const version_info *table;
774 switch (s->method->version) {
776 /* Version should match method version for non-ANY method */
777 return version_cmp(s, version, s->version) == 0;
778 case TLS_ANY_VERSION:
779 table = tls_version_table;
781 case DTLS_ANY_VERSION:
782 table = dtls_version_table;
787 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
789 if (vent->cmeth != NULL &&
790 version_cmp(s, version, vent->version) == 0 &&
791 ssl_method_error(s, vent->cmeth()) == 0) {
799 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
800 * fallback indication from a client check whether we're using the highest
801 * supported protocol version.
803 * @s server SSL handle.
805 * Returns 1 when using the highest enabled version, 0 otherwise.
807 int ssl_check_version_downgrade(SSL *s)
809 const version_info *vent;
810 const version_info *table;
813 * Check that the current protocol is the highest enabled version
814 * (according to s->ctx->method, as version negotiation may have changed
817 if (s->version == s->ctx->method->version)
821 * Apparently we're using a version-flexible SSL_METHOD (not at its
822 * highest protocol version).
824 if (s->ctx->method->version == TLS_method()->version)
825 table = tls_version_table;
826 else if (s->ctx->method->version == DTLS_method()->version)
827 table = dtls_version_table;
829 /* Unexpected state; fail closed. */
833 for (vent = table; vent->version != 0; ++vent) {
834 if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
835 return s->version == vent->version;
841 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
842 * protocols, provided the initial (D)TLS method is version-flexible. This
843 * function sanity-checks the proposed value and makes sure the method is
844 * version-flexible, then sets the limit if all is well.
846 * @method_version: The version of the current SSL_METHOD.
847 * @version: the intended limit.
848 * @bound: pointer to limit to be updated.
850 * Returns 1 on success, 0 on failure.
852 int ssl_set_version_bound(int method_version, int version, int *bound)
860 * Restrict TLS methods to TLS protocol versions.
861 * Restrict DTLS methods to DTLS protocol versions.
862 * Note, DTLS version numbers are decreasing, use comparison macros.
864 * Note that for both lower-bounds we use explicit versions, not
865 * (D)TLS_MIN_VERSION. This is because we don't want to break user
866 * configurations. If the MIN (supported) version ever rises, the user's
867 * "floor" remains valid even if no longer available. We don't expect the
868 * MAX ceiling to ever get lower, so making that variable makes sense.
870 switch (method_version) {
873 * XXX For fixed version methods, should we always fail and not set any
874 * bounds, always succeed and not set any bounds, or set the bounds and
875 * arrange to fail later if they are not met? At present fixed-version
876 * methods are not subject to controls that disable individual protocol
881 case TLS_ANY_VERSION:
882 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
886 case DTLS_ANY_VERSION:
887 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
888 DTLS_VERSION_LT(version, DTLS1_BAD_VER))
898 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
899 * client HELLO is received to select the final server protocol version and
900 * the version specific method.
902 * @s: server SSL handle.
904 * Returns 0 on success or an SSL error reason number on failure.
906 int ssl_choose_server_version(SSL *s, CLIENTHELLO_MSG *hello)
909 * With version-flexible methods we have an initial state with:
911 * s->method->version == (D)TLS_ANY_VERSION,
912 * s->version == (D)TLS_MAX_VERSION.
914 * So we detect version-flexible methods via the method version, not the
917 int server_version = s->method->version;
918 int client_version = hello->legacy_version;
919 const version_info *vent;
920 const version_info *table;
922 RAW_EXTENSION *suppversions;
924 s->client_version = client_version;
926 switch (server_version) {
929 * TODO(TLS1.3): This check will fail if someone attempts to do
930 * renegotiation in TLS1.3 at the moment. We need to ensure we disable
931 * renegotiation for TLS1.3
933 if (version_cmp(s, client_version, s->version) < 0)
934 return SSL_R_WRONG_SSL_VERSION;
936 * If this SSL handle is not from a version flexible method we don't
937 * (and never did) check min/max FIPS or Suite B constraints. Hope
938 * that's OK. It is up to the caller to not choose fixed protocol
939 * versions they don't want. If not, then easy to fix, just return
940 * ssl_method_error(s, s->method)
943 case TLS_ANY_VERSION:
944 table = tls_version_table;
946 case DTLS_ANY_VERSION:
947 table = dtls_version_table;
951 suppversions = &hello->pre_proc_exts[TLSEXT_IDX_supported_versions];
953 if (suppversions->present && !SSL_IS_DTLS(s)) {
954 unsigned int candidate_vers = 0;
955 unsigned int best_vers = 0;
956 const SSL_METHOD *best_method = NULL;
959 suppversions->parsed = 1;
961 if (!PACKET_as_length_prefixed_1(&suppversions->data, &versionslist)) {
962 /* Trailing or invalid data? */
963 return SSL_R_LENGTH_MISMATCH;
966 while (PACKET_get_net_2(&versionslist, &candidate_vers)) {
967 /* TODO(TLS1.3): Remove this before release */
968 if (candidate_vers == TLS1_3_VERSION_DRAFT)
969 candidate_vers = TLS1_3_VERSION;
971 * TODO(TLS1.3): There is some discussion on the TLS list about
972 * wheter to ignore versions <TLS1.2 in supported_versions. At the
973 * moment we honour them if present. To be reviewed later
975 if (version_cmp(s, candidate_vers, best_vers) <= 0)
978 vent->version != 0 && vent->version != (int)candidate_vers;
981 if (vent->version != 0 && vent->smeth != NULL) {
982 const SSL_METHOD *method;
984 method = vent->smeth();
985 if (ssl_method_error(s, method) == 0) {
986 best_vers = candidate_vers;
987 best_method = method;
991 if (PACKET_remaining(&versionslist) != 0) {
993 return SSL_R_LENGTH_MISMATCH;
997 s->version = best_vers;
998 s->method = best_method;
1001 return SSL_R_UNSUPPORTED_PROTOCOL;
1005 * If the supported versions extension isn't present, then the highest
1006 * version we can negotiate is TLSv1.2
1008 if (version_cmp(s, client_version, TLS1_3_VERSION) >= 0)
1009 client_version = TLS1_2_VERSION;
1012 * No supported versions extension, so we just use the version supplied in
1015 for (vent = table; vent->version != 0; ++vent) {
1016 const SSL_METHOD *method;
1018 if (vent->smeth == NULL ||
1019 version_cmp(s, client_version, vent->version) < 0)
1021 method = vent->smeth();
1022 if (ssl_method_error(s, method) == 0) {
1023 s->version = vent->version;
1029 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
1033 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
1034 * server HELLO is received to select the final client protocol version and
1035 * the version specific method.
1037 * @s: client SSL handle.
1038 * @version: The proposed version from the server's HELLO.
1040 * Returns 0 on success or an SSL error reason number on failure.
1042 int ssl_choose_client_version(SSL *s, int version)
1044 const version_info *vent;
1045 const version_info *table;
1047 /* TODO(TLS1.3): Remove this before release */
1048 if (version == TLS1_3_VERSION_DRAFT)
1049 version = TLS1_3_VERSION;
1051 switch (s->method->version) {
1053 if (version != s->version)
1054 return SSL_R_WRONG_SSL_VERSION;
1056 * If this SSL handle is not from a version flexible method we don't
1057 * (and never did) check min/max, FIPS or Suite B constraints. Hope
1058 * that's OK. It is up to the caller to not choose fixed protocol
1059 * versions they don't want. If not, then easy to fix, just return
1060 * ssl_method_error(s, s->method)
1063 case TLS_ANY_VERSION:
1064 table = tls_version_table;
1066 case DTLS_ANY_VERSION:
1067 table = dtls_version_table;
1071 for (vent = table; vent->version != 0; ++vent) {
1072 const SSL_METHOD *method;
1075 if (version != vent->version)
1077 if (vent->cmeth == NULL)
1079 method = vent->cmeth();
1080 err = ssl_method_error(s, method);
1084 s->version = version;
1088 return SSL_R_UNSUPPORTED_PROTOCOL;
1092 * ssl_get_client_min_max_version - get minimum and maximum client version
1093 * @s: The SSL connection
1094 * @min_version: The minimum supported version
1095 * @max_version: The maximum supported version
1097 * Work out what version we should be using for the initial ClientHello if the
1098 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
1099 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
1100 * or FIPS_mode() constraints and any floor imposed by the security level here,
1101 * so we don't advertise the wrong protocol version to only reject the outcome later.
1103 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
1104 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
1105 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
1107 * Returns 0 on success or an SSL error reason number on failure. On failure
1108 * min_version and max_version will also be set to 0.
1110 int ssl_get_client_min_max_version(const SSL *s, int *min_version,
1115 const SSL_METHOD *single = NULL;
1116 const SSL_METHOD *method;
1117 const version_info *table;
1118 const version_info *vent;
1120 switch (s->method->version) {
1123 * If this SSL handle is not from a version flexible method we don't
1124 * (and never did) check min/max FIPS or Suite B constraints. Hope
1125 * that's OK. It is up to the caller to not choose fixed protocol
1126 * versions they don't want. If not, then easy to fix, just return
1127 * ssl_method_error(s, s->method)
1129 *min_version = *max_version = s->version;
1131 case TLS_ANY_VERSION:
1132 table = tls_version_table;
1134 case DTLS_ANY_VERSION:
1135 table = dtls_version_table;
1140 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1141 * below X enabled. This is required in order to maintain the "version
1142 * capability" vector contiguous. Any versions with a NULL client method
1143 * (protocol version client is disabled at compile-time) is also a "hole".
1145 * Our initial state is hole == 1, version == 0. That is, versions above
1146 * the first version in the method table are disabled (a "hole" above
1147 * the valid protocol entries) and we don't have a selected version yet.
1149 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1150 * the selected version, and the method becomes a candidate "single"
1151 * method. We're no longer in a hole, so "hole" becomes 0.
1153 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1154 * as we support a contiguous range of at least two methods. If we hit
1155 * a disabled method, then hole becomes true again, but nothing else
1156 * changes yet, because all the remaining methods may be disabled too.
1157 * If we again hit an enabled method after the new hole, it becomes
1158 * selected, as we start from scratch.
1160 *min_version = version = 0;
1162 for (vent = table; vent->version != 0; ++vent) {
1164 * A table entry with a NULL client method is still a hole in the
1165 * "version capability" vector.
1167 if (vent->cmeth == NULL) {
1171 method = vent->cmeth();
1172 if (ssl_method_error(s, method) != 0) {
1176 *min_version = method->version;
1178 version = (single = method)->version;
1179 *min_version = version;
1184 *max_version = version;
1186 /* Fail if everything is disabled */
1188 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1194 * ssl_set_client_hello_version - Work out what version we should be using for
1195 * the initial ClientHello.legacy_version field.
1197 * @s: client SSL handle.
1199 * Returns 0 on success or an SSL error reason number on failure.
1201 int ssl_set_client_hello_version(SSL *s)
1203 int ver_min, ver_max, ret;
1205 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1210 s->version = ver_max;
1212 /* TLS1.3 always uses TLS1.2 in the legacy_version field */
1213 if (!SSL_IS_DTLS(s) && ver_max > TLS1_2_VERSION)
1214 ver_max = TLS1_2_VERSION;
1216 s->client_version = ver_max;