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)
34 ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
38 if (type == SSL3_RT_HANDSHAKE)
40 * should not be done for 'Hello Request's, but in that case we'll
41 * ignore the result anyway
43 if (!ssl3_finish_mac(s,
44 (unsigned char *)&s->init_buf->data[s->init_off],
48 if (ret == s->init_num) {
50 s->msg_callback(1, s->version, type, s->init_buf->data,
51 (size_t)(s->init_off + s->init_num), s,
60 int tls_close_construct_packet(SSL *s, WPACKET *pkt)
64 if (!WPACKET_close(pkt)
65 || !WPACKET_get_length(pkt, &msglen)
67 || !WPACKET_finish(pkt))
69 s->init_num = (int)msglen;
75 int tls_construct_finished(SSL *s, const char *sender, int slen)
81 p = ssl_handshake_start(s);
83 i = s->method->ssl3_enc->final_finish_mac(s,
85 s->s3->tmp.finish_md);
88 s->s3->tmp.finish_md_len = i;
89 memcpy(p, s->s3->tmp.finish_md, i);
93 * Copy the finished so we can use it for renegotiation checks
96 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
97 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
98 s->s3->previous_client_finished_len = i;
100 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
101 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
102 s->s3->previous_server_finished_len = i;
105 if (!ssl_set_handshake_header(s, SSL3_MT_FINISHED, l)) {
106 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
113 #ifndef OPENSSL_NO_NEXTPROTONEG
115 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
118 static void ssl3_take_mac(SSL *s)
123 * If no new cipher setup return immediately: other functions will set
124 * the appropriate error.
126 if (s->s3->tmp.new_cipher == NULL)
129 sender = s->method->ssl3_enc->server_finished_label;
130 slen = s->method->ssl3_enc->server_finished_label_len;
132 sender = s->method->ssl3_enc->client_finished_label;
133 slen = s->method->ssl3_enc->client_finished_label_len;
136 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
139 s->s3->tmp.peer_finish_md);
143 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
148 remain = PACKET_remaining(pkt);
150 * 'Change Cipher Spec' is just a single byte, which should already have
151 * been consumed by ssl_get_message() so there should be no bytes left,
152 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
154 if (SSL_IS_DTLS(s)) {
155 if ((s->version == DTLS1_BAD_VER
156 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
157 || (s->version != DTLS1_BAD_VER
158 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
159 al = SSL_AD_ILLEGAL_PARAMETER;
160 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
161 SSL_R_BAD_CHANGE_CIPHER_SPEC);
166 al = SSL_AD_ILLEGAL_PARAMETER;
167 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
168 SSL_R_BAD_CHANGE_CIPHER_SPEC);
173 /* Check we have a cipher to change to */
174 if (s->s3->tmp.new_cipher == NULL) {
175 al = SSL_AD_UNEXPECTED_MESSAGE;
176 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
180 s->s3->change_cipher_spec = 1;
181 if (!ssl3_do_change_cipher_spec(s)) {
182 al = SSL_AD_INTERNAL_ERROR;
183 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
187 if (SSL_IS_DTLS(s)) {
188 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
190 if (s->version == DTLS1_BAD_VER)
191 s->d1->handshake_read_seq++;
193 #ifndef OPENSSL_NO_SCTP
195 * Remember that a CCS has been received, so that an old key of
196 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
199 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
203 return MSG_PROCESS_CONTINUE_READING;
205 ssl3_send_alert(s, SSL3_AL_FATAL, al);
206 ossl_statem_set_error(s);
207 return MSG_PROCESS_ERROR;
210 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
214 /* If this occurs, we have missed a message */
215 if (!s->s3->change_cipher_spec) {
216 al = SSL_AD_UNEXPECTED_MESSAGE;
217 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
220 s->s3->change_cipher_spec = 0;
222 i = s->s3->tmp.peer_finish_md_len;
224 if ((unsigned long)i != PACKET_remaining(pkt)) {
225 al = SSL_AD_DECODE_ERROR;
226 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
230 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) {
231 al = SSL_AD_DECRYPT_ERROR;
232 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
237 * Copy the finished so we can use it for renegotiation checks
240 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
241 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
242 s->s3->previous_client_finished_len = i;
244 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
245 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
246 s->s3->previous_server_finished_len = i;
249 return MSG_PROCESS_FINISHED_READING;
251 ssl3_send_alert(s, SSL3_AL_FATAL, al);
252 ossl_statem_set_error(s);
253 return MSG_PROCESS_ERROR;
256 int tls_construct_change_cipher_spec(SSL *s)
260 p = (unsigned char *)s->init_buf->data;
268 unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk)
272 if (!WPACKET_init(&pkt, s->init_buf)) {
273 /* Should not happen */
274 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
278 if (!ssl_set_handshake_header2(s, &pkt, SSL3_MT_CERTIFICATE)
279 || !WPACKET_start_sub_packet_u24(&pkt)) {
280 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
284 if (!ssl_add_cert_chain(s, &pkt, cpk))
287 if (!WPACKET_close(&pkt) || !ssl_close_construct_packet(s, &pkt)) {
288 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
293 WPACKET_cleanup(&pkt);
297 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
299 void (*cb) (const SSL *ssl, int type, int val) = NULL;
301 #ifndef OPENSSL_NO_SCTP
302 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
304 ret = dtls_wait_for_dry(s);
305 if (ret != WORK_FINISHED_CONTINUE)
310 /* clean a few things up */
311 ssl3_cleanup_key_block(s);
313 if (!SSL_IS_DTLS(s)) {
315 * We don't do this in DTLS because we may still need the init_buf
316 * in case there are any unexpected retransmits
318 BUF_MEM_free(s->init_buf);
322 ssl_free_wbio_buffer(s);
326 if (!s->server || s->renegotiate == 2) {
327 /* skipped if we just sent a HelloRequest */
332 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
334 s->ctx->stats.sess_accept_good++;
335 s->handshake_func = ossl_statem_accept;
337 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
339 s->ctx->stats.sess_hit++;
341 s->handshake_func = ossl_statem_connect;
342 s->ctx->stats.sess_connect_good++;
345 if (s->info_callback != NULL)
346 cb = s->info_callback;
347 else if (s->ctx->info_callback != NULL)
348 cb = s->ctx->info_callback;
351 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
353 if (SSL_IS_DTLS(s)) {
354 /* done with handshaking */
355 s->d1->handshake_read_seq = 0;
356 s->d1->handshake_write_seq = 0;
357 s->d1->next_handshake_write_seq = 0;
358 dtls1_clear_received_buffer(s);
362 return WORK_FINISHED_STOP;
365 int tls_get_message_header(SSL *s, int *mt)
367 /* s->init_num < SSL3_HM_HEADER_LENGTH */
368 int skip_message, i, recvd_type, al;
372 p = (unsigned char *)s->init_buf->data;
375 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
376 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
378 SSL3_HM_HEADER_LENGTH - s->init_num,
381 s->rwstate = SSL_READING;
384 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
386 * A ChangeCipherSpec must be a single byte and may not occur
387 * in the middle of a handshake message.
389 if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) {
390 al = SSL_AD_UNEXPECTED_MESSAGE;
391 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
392 SSL_R_BAD_CHANGE_CIPHER_SPEC);
395 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
397 s->s3->tmp.message_size = i;
399 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
400 al = SSL_AD_UNEXPECTED_MESSAGE;
401 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
409 if (p[0] == SSL3_MT_HELLO_REQUEST)
411 * The server may always send 'Hello Request' messages --
412 * we are doing a handshake anyway now, so ignore them if
413 * their format is correct. Does not count for 'Finished'
416 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
421 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
422 p, SSL3_HM_HEADER_LENGTH, s,
423 s->msg_callback_arg);
425 } while (skip_message);
426 /* s->init_num == SSL3_HM_HEADER_LENGTH */
429 s->s3->tmp.message_type = *(p++);
431 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
433 * Only happens with SSLv3+ in an SSLv2 backward compatible
436 * Total message size is the remaining record bytes to read
437 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
439 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
440 + SSL3_HM_HEADER_LENGTH;
441 if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
442 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
445 s->s3->tmp.message_size = l;
447 s->init_msg = s->init_buf->data;
448 s->init_num = SSL3_HM_HEADER_LENGTH;
451 /* BUF_MEM_grow takes an 'int' parameter */
452 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
453 al = SSL_AD_ILLEGAL_PARAMETER;
454 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
457 if (l && !BUF_MEM_grow_clean(s->init_buf,
458 (int)l + SSL3_HM_HEADER_LENGTH)) {
459 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
462 s->s3->tmp.message_size = l;
464 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
470 ssl3_send_alert(s, SSL3_AL_FATAL, al);
475 int tls_get_message_body(SSL *s, unsigned long *len)
481 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
482 /* We've already read everything in */
483 *len = (unsigned long)s->init_num;
488 n = s->s3->tmp.message_size - s->init_num;
490 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
491 &p[s->init_num], n, 0);
493 s->rwstate = SSL_READING;
501 #ifndef OPENSSL_NO_NEXTPROTONEG
503 * If receiving Finished, record MAC of prior handshake messages for
504 * Finished verification.
506 if (*s->init_buf->data == SSL3_MT_FINISHED)
510 /* Feed this message into MAC computation. */
511 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
512 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
514 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
515 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
520 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
521 (size_t)s->init_num, s, s->msg_callback_arg);
523 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
524 s->init_num + SSL3_HM_HEADER_LENGTH)) {
525 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
526 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
531 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
532 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
533 s->msg_callback_arg);
537 * init_num should never be negative...should probably be declared
540 if (s->init_num < 0) {
541 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
542 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
546 *len = (unsigned long)s->init_num;
550 int ssl_cert_type(const X509 *x, const EVP_PKEY *pk)
552 if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL)
555 switch (EVP_PKEY_id(pk)) {
559 return SSL_PKEY_RSA_ENC;
561 return SSL_PKEY_DSA_SIGN;
562 #ifndef OPENSSL_NO_EC
566 #ifndef OPENSSL_NO_GOST
567 case NID_id_GostR3410_2001:
568 return SSL_PKEY_GOST01;
569 case NID_id_GostR3410_2012_256:
570 return SSL_PKEY_GOST12_256;
571 case NID_id_GostR3410_2012_512:
572 return SSL_PKEY_GOST12_512;
577 int ssl_verify_alarm_type(long type)
582 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
583 case X509_V_ERR_UNABLE_TO_GET_CRL:
584 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
585 al = SSL_AD_UNKNOWN_CA;
587 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
588 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
589 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
590 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
591 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
592 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
593 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
594 case X509_V_ERR_CERT_NOT_YET_VALID:
595 case X509_V_ERR_CRL_NOT_YET_VALID:
596 case X509_V_ERR_CERT_UNTRUSTED:
597 case X509_V_ERR_CERT_REJECTED:
598 case X509_V_ERR_HOSTNAME_MISMATCH:
599 case X509_V_ERR_EMAIL_MISMATCH:
600 case X509_V_ERR_IP_ADDRESS_MISMATCH:
601 case X509_V_ERR_DANE_NO_MATCH:
602 case X509_V_ERR_EE_KEY_TOO_SMALL:
603 case X509_V_ERR_CA_KEY_TOO_SMALL:
604 case X509_V_ERR_CA_MD_TOO_WEAK:
605 al = SSL_AD_BAD_CERTIFICATE;
607 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
608 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
609 al = SSL_AD_DECRYPT_ERROR;
611 case X509_V_ERR_CERT_HAS_EXPIRED:
612 case X509_V_ERR_CRL_HAS_EXPIRED:
613 al = SSL_AD_CERTIFICATE_EXPIRED;
615 case X509_V_ERR_CERT_REVOKED:
616 al = SSL_AD_CERTIFICATE_REVOKED;
618 case X509_V_ERR_UNSPECIFIED:
619 case X509_V_ERR_OUT_OF_MEM:
620 case X509_V_ERR_INVALID_CALL:
621 case X509_V_ERR_STORE_LOOKUP:
622 al = SSL_AD_INTERNAL_ERROR;
624 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
625 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
626 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
627 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
628 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
629 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
630 case X509_V_ERR_INVALID_CA:
631 al = SSL_AD_UNKNOWN_CA;
633 case X509_V_ERR_APPLICATION_VERIFICATION:
634 al = SSL_AD_HANDSHAKE_FAILURE;
636 case X509_V_ERR_INVALID_PURPOSE:
637 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
640 al = SSL_AD_CERTIFICATE_UNKNOWN;
646 int ssl_allow_compression(SSL *s)
648 if (s->options & SSL_OP_NO_COMPRESSION)
650 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
653 static int version_cmp(const SSL *s, int a, int b)
655 int dtls = SSL_IS_DTLS(s);
660 return a < b ? -1 : 1;
661 return DTLS_VERSION_LT(a, b) ? -1 : 1;
666 const SSL_METHOD *(*cmeth) (void);
667 const SSL_METHOD *(*smeth) (void);
670 #if TLS_MAX_VERSION != TLS1_2_VERSION
671 # error Code needs update for TLS_method() support beyond TLS1_2_VERSION.
674 static const version_info tls_version_table[] = {
675 #ifndef OPENSSL_NO_TLS1_2
676 {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
678 {TLS1_2_VERSION, NULL, NULL},
680 #ifndef OPENSSL_NO_TLS1_1
681 {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
683 {TLS1_1_VERSION, NULL, NULL},
685 #ifndef OPENSSL_NO_TLS1
686 {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
688 {TLS1_VERSION, NULL, NULL},
690 #ifndef OPENSSL_NO_SSL3
691 {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
693 {SSL3_VERSION, NULL, NULL},
698 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
699 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
702 static const version_info dtls_version_table[] = {
703 #ifndef OPENSSL_NO_DTLS1_2
704 {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
706 {DTLS1_2_VERSION, NULL, NULL},
708 #ifndef OPENSSL_NO_DTLS1
709 {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
710 {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
712 {DTLS1_VERSION, NULL, NULL},
713 {DTLS1_BAD_VER, NULL, NULL},
719 * ssl_method_error - Check whether an SSL_METHOD is enabled.
721 * @s: The SSL handle for the candidate method
722 * @method: the intended method.
724 * Returns 0 on success, or an SSL error reason on failure.
726 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
728 int version = method->version;
730 if ((s->min_proto_version != 0 &&
731 version_cmp(s, version, s->min_proto_version) < 0) ||
732 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
733 return SSL_R_VERSION_TOO_LOW;
735 if (s->max_proto_version != 0 &&
736 version_cmp(s, version, s->max_proto_version) > 0)
737 return SSL_R_VERSION_TOO_HIGH;
739 if ((s->options & method->mask) != 0)
740 return SSL_R_UNSUPPORTED_PROTOCOL;
741 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
742 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
743 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
744 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
750 * ssl_version_supported - Check that the specified `version` is supported by
753 * @s: The SSL handle for the candidate method
754 * @version: Protocol version to test against
756 * Returns 1 when supported, otherwise 0
758 int ssl_version_supported(const SSL *s, int version)
760 const version_info *vent;
761 const version_info *table;
763 switch (s->method->version) {
765 /* Version should match method version for non-ANY method */
766 return version_cmp(s, version, s->version) == 0;
767 case TLS_ANY_VERSION:
768 table = tls_version_table;
770 case DTLS_ANY_VERSION:
771 table = dtls_version_table;
776 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
778 if (vent->cmeth != NULL &&
779 version_cmp(s, version, vent->version) == 0 &&
780 ssl_method_error(s, vent->cmeth()) == 0) {
788 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
789 * fallback indication from a client check whether we're using the highest
790 * supported protocol version.
792 * @s server SSL handle.
794 * Returns 1 when using the highest enabled version, 0 otherwise.
796 int ssl_check_version_downgrade(SSL *s)
798 const version_info *vent;
799 const version_info *table;
802 * Check that the current protocol is the highest enabled version
803 * (according to s->ctx->method, as version negotiation may have changed
806 if (s->version == s->ctx->method->version)
810 * Apparently we're using a version-flexible SSL_METHOD (not at its
811 * highest protocol version).
813 if (s->ctx->method->version == TLS_method()->version)
814 table = tls_version_table;
815 else if (s->ctx->method->version == DTLS_method()->version)
816 table = dtls_version_table;
818 /* Unexpected state; fail closed. */
822 for (vent = table; vent->version != 0; ++vent) {
823 if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
824 return s->version == vent->version;
830 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
831 * protocols, provided the initial (D)TLS method is version-flexible. This
832 * function sanity-checks the proposed value and makes sure the method is
833 * version-flexible, then sets the limit if all is well.
835 * @method_version: The version of the current SSL_METHOD.
836 * @version: the intended limit.
837 * @bound: pointer to limit to be updated.
839 * Returns 1 on success, 0 on failure.
841 int ssl_set_version_bound(int method_version, int version, int *bound)
849 * Restrict TLS methods to TLS protocol versions.
850 * Restrict DTLS methods to DTLS protocol versions.
851 * Note, DTLS version numbers are decreasing, use comparison macros.
853 * Note that for both lower-bounds we use explicit versions, not
854 * (D)TLS_MIN_VERSION. This is because we don't want to break user
855 * configurations. If the MIN (supported) version ever rises, the user's
856 * "floor" remains valid even if no longer available. We don't expect the
857 * MAX ceiling to ever get lower, so making that variable makes sense.
859 switch (method_version) {
862 * XXX For fixed version methods, should we always fail and not set any
863 * bounds, always succeed and not set any bounds, or set the bounds and
864 * arrange to fail later if they are not met? At present fixed-version
865 * methods are not subject to controls that disable individual protocol
870 case TLS_ANY_VERSION:
871 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
875 case DTLS_ANY_VERSION:
876 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
877 DTLS_VERSION_LT(version, DTLS1_BAD_VER))
887 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
888 * client HELLO is received to select the final server protocol version and
889 * the version specific method.
891 * @s: server SSL handle.
893 * Returns 0 on success or an SSL error reason number on failure.
895 int ssl_choose_server_version(SSL *s)
898 * With version-flexible methods we have an initial state with:
900 * s->method->version == (D)TLS_ANY_VERSION,
901 * s->version == (D)TLS_MAX_VERSION.
903 * So we detect version-flexible methods via the method version, not the
906 int server_version = s->method->version;
907 int client_version = s->client_version;
908 const version_info *vent;
909 const version_info *table;
912 switch (server_version) {
914 if (version_cmp(s, client_version, s->version) < 0)
915 return SSL_R_WRONG_SSL_VERSION;
917 * If this SSL handle is not from a version flexible method we don't
918 * (and never did) check min/max FIPS or Suite B constraints. Hope
919 * that's OK. It is up to the caller to not choose fixed protocol
920 * versions they don't want. If not, then easy to fix, just return
921 * ssl_method_error(s, s->method)
924 case TLS_ANY_VERSION:
925 table = tls_version_table;
927 case DTLS_ANY_VERSION:
928 table = dtls_version_table;
932 for (vent = table; vent->version != 0; ++vent) {
933 const SSL_METHOD *method;
935 if (vent->smeth == NULL ||
936 version_cmp(s, client_version, vent->version) < 0)
938 method = vent->smeth();
939 if (ssl_method_error(s, method) == 0) {
940 s->version = vent->version;
946 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
950 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
951 * server HELLO is received to select the final client protocol version and
952 * the version specific method.
954 * @s: client SSL handle.
955 * @version: The proposed version from the server's HELLO.
957 * Returns 0 on success or an SSL error reason number on failure.
959 int ssl_choose_client_version(SSL *s, int version)
961 const version_info *vent;
962 const version_info *table;
964 switch (s->method->version) {
966 if (version != s->version)
967 return SSL_R_WRONG_SSL_VERSION;
969 * If this SSL handle is not from a version flexible method we don't
970 * (and never did) check min/max, FIPS or Suite B constraints. Hope
971 * that's OK. It is up to the caller to not choose fixed protocol
972 * versions they don't want. If not, then easy to fix, just return
973 * ssl_method_error(s, s->method)
976 case TLS_ANY_VERSION:
977 table = tls_version_table;
979 case DTLS_ANY_VERSION:
980 table = dtls_version_table;
984 for (vent = table; vent->version != 0; ++vent) {
985 const SSL_METHOD *method;
988 if (version != vent->version)
990 if (vent->cmeth == NULL)
992 method = vent->cmeth();
993 err = ssl_method_error(s, method);
997 s->version = version;
1001 return SSL_R_UNSUPPORTED_PROTOCOL;
1005 * ssl_get_client_min_max_version - get minimum and maximum client version
1006 * @s: The SSL connection
1007 * @min_version: The minimum supported version
1008 * @max_version: The maximum supported version
1010 * Work out what version we should be using for the initial ClientHello if the
1011 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
1012 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
1013 * or FIPS_mode() constraints and any floor imposed by the security level here,
1014 * so we don't advertise the wrong protocol version to only reject the outcome later.
1016 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
1017 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
1018 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
1020 * Returns 0 on success or an SSL error reason number on failure. On failure
1021 * min_version and max_version will also be set to 0.
1023 int ssl_get_client_min_max_version(const SSL *s, int *min_version,
1028 const SSL_METHOD *single = NULL;
1029 const SSL_METHOD *method;
1030 const version_info *table;
1031 const version_info *vent;
1033 switch (s->method->version) {
1036 * If this SSL handle is not from a version flexible method we don't
1037 * (and never did) check min/max FIPS or Suite B constraints. Hope
1038 * that's OK. It is up to the caller to not choose fixed protocol
1039 * versions they don't want. If not, then easy to fix, just return
1040 * ssl_method_error(s, s->method)
1042 *min_version = *max_version = s->version;
1044 case TLS_ANY_VERSION:
1045 table = tls_version_table;
1047 case DTLS_ANY_VERSION:
1048 table = dtls_version_table;
1053 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1054 * below X enabled. This is required in order to maintain the "version
1055 * capability" vector contiguous. Any versions with a NULL client method
1056 * (protocol version client is disabled at compile-time) is also a "hole".
1058 * Our initial state is hole == 1, version == 0. That is, versions above
1059 * the first version in the method table are disabled (a "hole" above
1060 * the valid protocol entries) and we don't have a selected version yet.
1062 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1063 * the selected version, and the method becomes a candidate "single"
1064 * method. We're no longer in a hole, so "hole" becomes 0.
1066 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1067 * as we support a contiguous range of at least two methods. If we hit
1068 * a disabled method, then hole becomes true again, but nothing else
1069 * changes yet, because all the remaining methods may be disabled too.
1070 * If we again hit an enabled method after the new hole, it becomes
1071 * selected, as we start from scratch.
1073 *min_version = version = 0;
1075 for (vent = table; vent->version != 0; ++vent) {
1077 * A table entry with a NULL client method is still a hole in the
1078 * "version capability" vector.
1080 if (vent->cmeth == NULL) {
1084 method = vent->cmeth();
1085 if (ssl_method_error(s, method) != 0) {
1089 *min_version = method->version;
1091 version = (single = method)->version;
1092 *min_version = version;
1097 *max_version = version;
1099 /* Fail if everything is disabled */
1101 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1107 * ssl_set_client_hello_version - Work out what version we should be using for
1108 * the initial ClientHello.
1110 * @s: client SSL handle.
1112 * Returns 0 on success or an SSL error reason number on failure.
1114 int ssl_set_client_hello_version(SSL *s)
1116 int ver_min, ver_max, ret;
1118 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1123 s->client_version = s->version = ver_max;