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)
68 s->init_num = (int)msglen;
74 int tls_construct_finished(SSL *s, WPACKET *pkt, const char *sender, int slen)
78 if (!ssl_set_handshake_header(s, pkt, SSL3_MT_FINISHED)) {
79 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
83 i = s->method->ssl3_enc->final_finish_mac(s,
85 s->s3->tmp.finish_md);
87 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
91 s->s3->tmp.finish_md_len = i;
93 if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, i)) {
94 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
99 * Copy the finished so we can use it for renegotiation checks
102 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
103 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
104 s->s3->previous_client_finished_len = i;
106 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
107 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
108 s->s3->previous_server_finished_len = i;
111 if (!ssl_close_construct_packet(s, pkt)) {
112 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
118 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
122 #ifndef OPENSSL_NO_NEXTPROTONEG
124 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
127 static void ssl3_take_mac(SSL *s)
132 * If no new cipher setup return immediately: other functions will set
133 * the appropriate error.
135 if (s->s3->tmp.new_cipher == NULL)
138 sender = s->method->ssl3_enc->server_finished_label;
139 slen = s->method->ssl3_enc->server_finished_label_len;
141 sender = s->method->ssl3_enc->client_finished_label;
142 slen = s->method->ssl3_enc->client_finished_label_len;
145 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
148 s->s3->tmp.peer_finish_md);
152 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
157 remain = PACKET_remaining(pkt);
159 * 'Change Cipher Spec' is just a single byte, which should already have
160 * been consumed by ssl_get_message() so there should be no bytes left,
161 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
163 if (SSL_IS_DTLS(s)) {
164 if ((s->version == DTLS1_BAD_VER
165 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
166 || (s->version != DTLS1_BAD_VER
167 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
168 al = SSL_AD_ILLEGAL_PARAMETER;
169 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
170 SSL_R_BAD_CHANGE_CIPHER_SPEC);
175 al = SSL_AD_ILLEGAL_PARAMETER;
176 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
177 SSL_R_BAD_CHANGE_CIPHER_SPEC);
182 /* Check we have a cipher to change to */
183 if (s->s3->tmp.new_cipher == NULL) {
184 al = SSL_AD_UNEXPECTED_MESSAGE;
185 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
189 s->s3->change_cipher_spec = 1;
190 if (!ssl3_do_change_cipher_spec(s)) {
191 al = SSL_AD_INTERNAL_ERROR;
192 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
196 if (SSL_IS_DTLS(s)) {
197 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
199 if (s->version == DTLS1_BAD_VER)
200 s->d1->handshake_read_seq++;
202 #ifndef OPENSSL_NO_SCTP
204 * Remember that a CCS has been received, so that an old key of
205 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
208 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
212 return MSG_PROCESS_CONTINUE_READING;
214 ssl3_send_alert(s, SSL3_AL_FATAL, al);
215 ossl_statem_set_error(s);
216 return MSG_PROCESS_ERROR;
219 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
223 /* If this occurs, we have missed a message */
224 if (!s->s3->change_cipher_spec) {
225 al = SSL_AD_UNEXPECTED_MESSAGE;
226 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
229 s->s3->change_cipher_spec = 0;
231 i = s->s3->tmp.peer_finish_md_len;
233 if ((unsigned long)i != PACKET_remaining(pkt)) {
234 al = SSL_AD_DECODE_ERROR;
235 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
239 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) {
240 al = SSL_AD_DECRYPT_ERROR;
241 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
246 * Copy the finished so we can use it for renegotiation checks
249 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
250 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
251 s->s3->previous_client_finished_len = i;
253 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
254 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
255 s->s3->previous_server_finished_len = i;
258 return MSG_PROCESS_FINISHED_READING;
260 ssl3_send_alert(s, SSL3_AL_FATAL, al);
261 ossl_statem_set_error(s);
262 return MSG_PROCESS_ERROR;
265 int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
267 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) {
268 SSLerr(SSL_F_TLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
269 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
279 unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk)
281 if (!ssl_set_handshake_header(s, pkt, SSL3_MT_CERTIFICATE)
282 || !WPACKET_start_sub_packet_u24(pkt)
283 || !ssl_add_cert_chain(s, pkt, cpk)
284 || !WPACKET_close(pkt)
285 || !ssl_close_construct_packet(s, pkt)) {
286 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
292 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
294 void (*cb) (const SSL *ssl, int type, int val) = NULL;
296 #ifndef OPENSSL_NO_SCTP
297 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
299 ret = dtls_wait_for_dry(s);
300 if (ret != WORK_FINISHED_CONTINUE)
305 /* clean a few things up */
306 ssl3_cleanup_key_block(s);
308 if (!SSL_IS_DTLS(s)) {
310 * We don't do this in DTLS because we may still need the init_buf
311 * in case there are any unexpected retransmits
313 BUF_MEM_free(s->init_buf);
317 ssl_free_wbio_buffer(s);
321 if (!s->server || s->renegotiate == 2) {
322 /* skipped if we just sent a HelloRequest */
327 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
329 s->ctx->stats.sess_accept_good++;
330 s->handshake_func = ossl_statem_accept;
332 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
334 s->ctx->stats.sess_hit++;
336 s->handshake_func = ossl_statem_connect;
337 s->ctx->stats.sess_connect_good++;
340 if (s->info_callback != NULL)
341 cb = s->info_callback;
342 else if (s->ctx->info_callback != NULL)
343 cb = s->ctx->info_callback;
346 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
348 if (SSL_IS_DTLS(s)) {
349 /* done with handshaking */
350 s->d1->handshake_read_seq = 0;
351 s->d1->handshake_write_seq = 0;
352 s->d1->next_handshake_write_seq = 0;
353 dtls1_clear_received_buffer(s);
357 return WORK_FINISHED_STOP;
360 int tls_get_message_header(SSL *s, int *mt)
362 /* s->init_num < SSL3_HM_HEADER_LENGTH */
363 int skip_message, i, recvd_type, al;
367 p = (unsigned char *)s->init_buf->data;
370 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
371 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
373 SSL3_HM_HEADER_LENGTH - s->init_num,
376 s->rwstate = SSL_READING;
379 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
381 * A ChangeCipherSpec must be a single byte and may not occur
382 * in the middle of a handshake message.
384 if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) {
385 al = SSL_AD_UNEXPECTED_MESSAGE;
386 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
387 SSL_R_BAD_CHANGE_CIPHER_SPEC);
390 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
392 s->s3->tmp.message_size = i;
394 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
395 al = SSL_AD_UNEXPECTED_MESSAGE;
396 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
404 if (p[0] == SSL3_MT_HELLO_REQUEST)
406 * The server may always send 'Hello Request' messages --
407 * we are doing a handshake anyway now, so ignore them if
408 * their format is correct. Does not count for 'Finished'
411 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
416 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
417 p, SSL3_HM_HEADER_LENGTH, s,
418 s->msg_callback_arg);
420 } while (skip_message);
421 /* s->init_num == SSL3_HM_HEADER_LENGTH */
424 s->s3->tmp.message_type = *(p++);
426 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
428 * Only happens with SSLv3+ in an SSLv2 backward compatible
431 * Total message size is the remaining record bytes to read
432 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
434 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
435 + SSL3_HM_HEADER_LENGTH;
436 s->s3->tmp.message_size = l;
438 s->init_msg = s->init_buf->data;
439 s->init_num = SSL3_HM_HEADER_LENGTH;
442 /* BUF_MEM_grow takes an 'int' parameter */
443 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
444 al = SSL_AD_ILLEGAL_PARAMETER;
445 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
448 s->s3->tmp.message_size = l;
450 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
456 ssl3_send_alert(s, SSL3_AL_FATAL, al);
460 int tls_get_message_body(SSL *s, unsigned long *len)
466 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
467 /* We've already read everything in */
468 *len = (unsigned long)s->init_num;
473 n = s->s3->tmp.message_size - s->init_num;
475 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
476 &p[s->init_num], n, 0);
478 s->rwstate = SSL_READING;
486 #ifndef OPENSSL_NO_NEXTPROTONEG
488 * If receiving Finished, record MAC of prior handshake messages for
489 * Finished verification.
491 if (*s->init_buf->data == SSL3_MT_FINISHED)
495 /* Feed this message into MAC computation. */
496 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
497 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
499 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
500 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
505 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
506 (size_t)s->init_num, s, s->msg_callback_arg);
508 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
509 s->init_num + SSL3_HM_HEADER_LENGTH)) {
510 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
511 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
516 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
517 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
518 s->msg_callback_arg);
522 * init_num should never be negative...should probably be declared
525 if (s->init_num < 0) {
526 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
527 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
531 *len = (unsigned long)s->init_num;
535 int ssl_cert_type(const X509 *x, const EVP_PKEY *pk)
537 if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL)
540 switch (EVP_PKEY_id(pk)) {
544 return SSL_PKEY_RSA_ENC;
546 return SSL_PKEY_DSA_SIGN;
547 #ifndef OPENSSL_NO_EC
551 #ifndef OPENSSL_NO_GOST
552 case NID_id_GostR3410_2001:
553 return SSL_PKEY_GOST01;
554 case NID_id_GostR3410_2012_256:
555 return SSL_PKEY_GOST12_256;
556 case NID_id_GostR3410_2012_512:
557 return SSL_PKEY_GOST12_512;
562 int ssl_verify_alarm_type(long type)
567 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
568 case X509_V_ERR_UNABLE_TO_GET_CRL:
569 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
570 al = SSL_AD_UNKNOWN_CA;
572 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
573 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
574 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
575 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
576 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
577 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
578 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
579 case X509_V_ERR_CERT_NOT_YET_VALID:
580 case X509_V_ERR_CRL_NOT_YET_VALID:
581 case X509_V_ERR_CERT_UNTRUSTED:
582 case X509_V_ERR_CERT_REJECTED:
583 case X509_V_ERR_HOSTNAME_MISMATCH:
584 case X509_V_ERR_EMAIL_MISMATCH:
585 case X509_V_ERR_IP_ADDRESS_MISMATCH:
586 case X509_V_ERR_DANE_NO_MATCH:
587 case X509_V_ERR_EE_KEY_TOO_SMALL:
588 case X509_V_ERR_CA_KEY_TOO_SMALL:
589 case X509_V_ERR_CA_MD_TOO_WEAK:
590 al = SSL_AD_BAD_CERTIFICATE;
592 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
593 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
594 al = SSL_AD_DECRYPT_ERROR;
596 case X509_V_ERR_CERT_HAS_EXPIRED:
597 case X509_V_ERR_CRL_HAS_EXPIRED:
598 al = SSL_AD_CERTIFICATE_EXPIRED;
600 case X509_V_ERR_CERT_REVOKED:
601 al = SSL_AD_CERTIFICATE_REVOKED;
603 case X509_V_ERR_UNSPECIFIED:
604 case X509_V_ERR_OUT_OF_MEM:
605 case X509_V_ERR_INVALID_CALL:
606 case X509_V_ERR_STORE_LOOKUP:
607 al = SSL_AD_INTERNAL_ERROR;
609 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
610 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
611 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
612 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
613 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
614 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
615 case X509_V_ERR_INVALID_CA:
616 al = SSL_AD_UNKNOWN_CA;
618 case X509_V_ERR_APPLICATION_VERIFICATION:
619 al = SSL_AD_HANDSHAKE_FAILURE;
621 case X509_V_ERR_INVALID_PURPOSE:
622 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
625 al = SSL_AD_CERTIFICATE_UNKNOWN;
631 int ssl_allow_compression(SSL *s)
633 if (s->options & SSL_OP_NO_COMPRESSION)
635 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
638 static int version_cmp(const SSL *s, int a, int b)
640 int dtls = SSL_IS_DTLS(s);
645 return a < b ? -1 : 1;
646 return DTLS_VERSION_LT(a, b) ? -1 : 1;
651 const SSL_METHOD *(*cmeth) (void);
652 const SSL_METHOD *(*smeth) (void);
655 #if TLS_MAX_VERSION != TLS1_2_VERSION
656 # error Code needs update for TLS_method() support beyond TLS1_2_VERSION.
659 static const version_info tls_version_table[] = {
660 #ifndef OPENSSL_NO_TLS1_2
661 {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
663 {TLS1_2_VERSION, NULL, NULL},
665 #ifndef OPENSSL_NO_TLS1_1
666 {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
668 {TLS1_1_VERSION, NULL, NULL},
670 #ifndef OPENSSL_NO_TLS1
671 {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
673 {TLS1_VERSION, NULL, NULL},
675 #ifndef OPENSSL_NO_SSL3
676 {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
678 {SSL3_VERSION, NULL, NULL},
683 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
684 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
687 static const version_info dtls_version_table[] = {
688 #ifndef OPENSSL_NO_DTLS1_2
689 {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
691 {DTLS1_2_VERSION, NULL, NULL},
693 #ifndef OPENSSL_NO_DTLS1
694 {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
695 {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
697 {DTLS1_VERSION, NULL, NULL},
698 {DTLS1_BAD_VER, NULL, NULL},
704 * ssl_method_error - Check whether an SSL_METHOD is enabled.
706 * @s: The SSL handle for the candidate method
707 * @method: the intended method.
709 * Returns 0 on success, or an SSL error reason on failure.
711 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
713 int version = method->version;
715 if ((s->min_proto_version != 0 &&
716 version_cmp(s, version, s->min_proto_version) < 0) ||
717 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
718 return SSL_R_VERSION_TOO_LOW;
720 if (s->max_proto_version != 0 &&
721 version_cmp(s, version, s->max_proto_version) > 0)
722 return SSL_R_VERSION_TOO_HIGH;
724 if ((s->options & method->mask) != 0)
725 return SSL_R_UNSUPPORTED_PROTOCOL;
726 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
727 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
728 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
729 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
735 * ssl_version_supported - Check that the specified `version` is supported by
738 * @s: The SSL handle for the candidate method
739 * @version: Protocol version to test against
741 * Returns 1 when supported, otherwise 0
743 int ssl_version_supported(const SSL *s, int version)
745 const version_info *vent;
746 const version_info *table;
748 switch (s->method->version) {
750 /* Version should match method version for non-ANY method */
751 return version_cmp(s, version, s->version) == 0;
752 case TLS_ANY_VERSION:
753 table = tls_version_table;
755 case DTLS_ANY_VERSION:
756 table = dtls_version_table;
761 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
763 if (vent->cmeth != NULL &&
764 version_cmp(s, version, vent->version) == 0 &&
765 ssl_method_error(s, vent->cmeth()) == 0) {
773 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
774 * fallback indication from a client check whether we're using the highest
775 * supported protocol version.
777 * @s server SSL handle.
779 * Returns 1 when using the highest enabled version, 0 otherwise.
781 int ssl_check_version_downgrade(SSL *s)
783 const version_info *vent;
784 const version_info *table;
787 * Check that the current protocol is the highest enabled version
788 * (according to s->ctx->method, as version negotiation may have changed
791 if (s->version == s->ctx->method->version)
795 * Apparently we're using a version-flexible SSL_METHOD (not at its
796 * highest protocol version).
798 if (s->ctx->method->version == TLS_method()->version)
799 table = tls_version_table;
800 else if (s->ctx->method->version == DTLS_method()->version)
801 table = dtls_version_table;
803 /* Unexpected state; fail closed. */
807 for (vent = table; vent->version != 0; ++vent) {
808 if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
809 return s->version == vent->version;
815 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
816 * protocols, provided the initial (D)TLS method is version-flexible. This
817 * function sanity-checks the proposed value and makes sure the method is
818 * version-flexible, then sets the limit if all is well.
820 * @method_version: The version of the current SSL_METHOD.
821 * @version: the intended limit.
822 * @bound: pointer to limit to be updated.
824 * Returns 1 on success, 0 on failure.
826 int ssl_set_version_bound(int method_version, int version, int *bound)
834 * Restrict TLS methods to TLS protocol versions.
835 * Restrict DTLS methods to DTLS protocol versions.
836 * Note, DTLS version numbers are decreasing, use comparison macros.
838 * Note that for both lower-bounds we use explicit versions, not
839 * (D)TLS_MIN_VERSION. This is because we don't want to break user
840 * configurations. If the MIN (supported) version ever rises, the user's
841 * "floor" remains valid even if no longer available. We don't expect the
842 * MAX ceiling to ever get lower, so making that variable makes sense.
844 switch (method_version) {
847 * XXX For fixed version methods, should we always fail and not set any
848 * bounds, always succeed and not set any bounds, or set the bounds and
849 * arrange to fail later if they are not met? At present fixed-version
850 * methods are not subject to controls that disable individual protocol
855 case TLS_ANY_VERSION:
856 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
860 case DTLS_ANY_VERSION:
861 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
862 DTLS_VERSION_LT(version, DTLS1_BAD_VER))
872 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
873 * client HELLO is received to select the final server protocol version and
874 * the version specific method.
876 * @s: server SSL handle.
878 * Returns 0 on success or an SSL error reason number on failure.
880 int ssl_choose_server_version(SSL *s)
883 * With version-flexible methods we have an initial state with:
885 * s->method->version == (D)TLS_ANY_VERSION,
886 * s->version == (D)TLS_MAX_VERSION.
888 * So we detect version-flexible methods via the method version, not the
891 int server_version = s->method->version;
892 int client_version = s->client_version;
893 const version_info *vent;
894 const version_info *table;
897 switch (server_version) {
899 if (version_cmp(s, client_version, s->version) < 0)
900 return SSL_R_WRONG_SSL_VERSION;
902 * If this SSL handle is not from a version flexible method we don't
903 * (and never did) check min/max FIPS or Suite B constraints. Hope
904 * that's OK. It is up to the caller to not choose fixed protocol
905 * versions they don't want. If not, then easy to fix, just return
906 * ssl_method_error(s, s->method)
909 case TLS_ANY_VERSION:
910 table = tls_version_table;
912 case DTLS_ANY_VERSION:
913 table = dtls_version_table;
917 for (vent = table; vent->version != 0; ++vent) {
918 const SSL_METHOD *method;
920 if (vent->smeth == NULL ||
921 version_cmp(s, client_version, vent->version) < 0)
923 method = vent->smeth();
924 if (ssl_method_error(s, method) == 0) {
925 s->version = vent->version;
931 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
935 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
936 * server HELLO is received to select the final client protocol version and
937 * the version specific method.
939 * @s: client SSL handle.
940 * @version: The proposed version from the server's HELLO.
942 * Returns 0 on success or an SSL error reason number on failure.
944 int ssl_choose_client_version(SSL *s, int version)
946 const version_info *vent;
947 const version_info *table;
949 switch (s->method->version) {
951 if (version != s->version)
952 return SSL_R_WRONG_SSL_VERSION;
954 * If this SSL handle is not from a version flexible method we don't
955 * (and never did) check min/max, FIPS or Suite B constraints. Hope
956 * that's OK. It is up to the caller to not choose fixed protocol
957 * versions they don't want. If not, then easy to fix, just return
958 * ssl_method_error(s, s->method)
961 case TLS_ANY_VERSION:
962 table = tls_version_table;
964 case DTLS_ANY_VERSION:
965 table = dtls_version_table;
969 for (vent = table; vent->version != 0; ++vent) {
970 const SSL_METHOD *method;
973 if (version != vent->version)
975 if (vent->cmeth == NULL)
977 method = vent->cmeth();
978 err = ssl_method_error(s, method);
982 s->version = version;
986 return SSL_R_UNSUPPORTED_PROTOCOL;
990 * ssl_get_client_min_max_version - get minimum and maximum client version
991 * @s: The SSL connection
992 * @min_version: The minimum supported version
993 * @max_version: The maximum supported version
995 * Work out what version we should be using for the initial ClientHello if the
996 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
997 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
998 * or FIPS_mode() constraints and any floor imposed by the security level here,
999 * so we don't advertise the wrong protocol version to only reject the outcome later.
1001 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
1002 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
1003 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
1005 * Returns 0 on success or an SSL error reason number on failure. On failure
1006 * min_version and max_version will also be set to 0.
1008 int ssl_get_client_min_max_version(const SSL *s, int *min_version,
1013 const SSL_METHOD *single = NULL;
1014 const SSL_METHOD *method;
1015 const version_info *table;
1016 const version_info *vent;
1018 switch (s->method->version) {
1021 * If this SSL handle is not from a version flexible method we don't
1022 * (and never did) check min/max FIPS or Suite B constraints. Hope
1023 * that's OK. It is up to the caller to not choose fixed protocol
1024 * versions they don't want. If not, then easy to fix, just return
1025 * ssl_method_error(s, s->method)
1027 *min_version = *max_version = s->version;
1029 case TLS_ANY_VERSION:
1030 table = tls_version_table;
1032 case DTLS_ANY_VERSION:
1033 table = dtls_version_table;
1038 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1039 * below X enabled. This is required in order to maintain the "version
1040 * capability" vector contiguous. Any versions with a NULL client method
1041 * (protocol version client is disabled at compile-time) is also a "hole".
1043 * Our initial state is hole == 1, version == 0. That is, versions above
1044 * the first version in the method table are disabled (a "hole" above
1045 * the valid protocol entries) and we don't have a selected version yet.
1047 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1048 * the selected version, and the method becomes a candidate "single"
1049 * method. We're no longer in a hole, so "hole" becomes 0.
1051 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1052 * as we support a contiguous range of at least two methods. If we hit
1053 * a disabled method, then hole becomes true again, but nothing else
1054 * changes yet, because all the remaining methods may be disabled too.
1055 * If we again hit an enabled method after the new hole, it becomes
1056 * selected, as we start from scratch.
1058 *min_version = version = 0;
1060 for (vent = table; vent->version != 0; ++vent) {
1062 * A table entry with a NULL client method is still a hole in the
1063 * "version capability" vector.
1065 if (vent->cmeth == NULL) {
1069 method = vent->cmeth();
1070 if (ssl_method_error(s, method) != 0) {
1074 *min_version = method->version;
1076 version = (single = method)->version;
1077 *min_version = version;
1082 *max_version = version;
1084 /* Fail if everything is disabled */
1086 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1092 * ssl_set_client_hello_version - Work out what version we should be using for
1093 * the initial ClientHello.
1095 * @s: client SSL handle.
1097 * Returns 0 on success or an SSL error reason number on failure.
1099 int ssl_set_client_hello_version(SSL *s)
1101 int ver_min, ver_max, ret;
1103 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1108 s->client_version = s->version = ver_max;