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 ssl3_finish_mac(s, (unsigned char *)&s->init_buf->data[s->init_off],
46 if (ret == s->init_num) {
48 s->msg_callback(1, s->version, type, s->init_buf->data,
49 (size_t)(s->init_off + s->init_num), s,
58 int tls_construct_finished(SSL *s, const char *sender, int slen)
64 p = ssl_handshake_start(s);
66 i = s->method->ssl3_enc->final_finish_mac(s,
68 s->s3->tmp.finish_md);
71 s->s3->tmp.finish_md_len = i;
72 memcpy(p, s->s3->tmp.finish_md, i);
76 * Copy the finished so we can use it for renegotiation checks
79 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
80 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
81 s->s3->previous_client_finished_len = i;
83 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
84 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
85 s->s3->previous_server_finished_len = i;
88 if (!ssl_set_handshake_header(s, SSL3_MT_FINISHED, l)) {
89 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
96 #ifndef OPENSSL_NO_NEXTPROTONEG
98 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
101 static void ssl3_take_mac(SSL *s)
106 * If no new cipher setup return immediately: other functions will set
107 * the appropriate error.
109 if (s->s3->tmp.new_cipher == NULL)
112 sender = s->method->ssl3_enc->server_finished_label;
113 slen = s->method->ssl3_enc->server_finished_label_len;
115 sender = s->method->ssl3_enc->client_finished_label;
116 slen = s->method->ssl3_enc->client_finished_label_len;
119 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
122 s->s3->tmp.peer_finish_md);
126 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
131 remain = PACKET_remaining(pkt);
133 * 'Change Cipher Spec' is just a single byte, which should already have
134 * been consumed by ssl_get_message() so there should be no bytes left,
135 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
137 if (SSL_IS_DTLS(s)) {
138 if ((s->version == DTLS1_BAD_VER
139 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
140 || (s->version != DTLS1_BAD_VER
141 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
142 al = SSL_AD_ILLEGAL_PARAMETER;
143 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
144 SSL_R_BAD_CHANGE_CIPHER_SPEC);
149 al = SSL_AD_ILLEGAL_PARAMETER;
150 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
151 SSL_R_BAD_CHANGE_CIPHER_SPEC);
156 /* Check we have a cipher to change to */
157 if (s->s3->tmp.new_cipher == NULL) {
158 al = SSL_AD_UNEXPECTED_MESSAGE;
159 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
163 s->s3->change_cipher_spec = 1;
164 if (!ssl3_do_change_cipher_spec(s)) {
165 al = SSL_AD_INTERNAL_ERROR;
166 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
170 if (SSL_IS_DTLS(s)) {
171 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
173 if (s->version == DTLS1_BAD_VER)
174 s->d1->handshake_read_seq++;
176 #ifndef OPENSSL_NO_SCTP
178 * Remember that a CCS has been received, so that an old key of
179 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
182 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
186 return MSG_PROCESS_CONTINUE_READING;
188 ssl3_send_alert(s, SSL3_AL_FATAL, al);
189 ossl_statem_set_error(s);
190 return MSG_PROCESS_ERROR;
193 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
197 /* If this occurs, we have missed a message */
198 if (!s->s3->change_cipher_spec) {
199 al = SSL_AD_UNEXPECTED_MESSAGE;
200 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
203 s->s3->change_cipher_spec = 0;
205 i = s->s3->tmp.peer_finish_md_len;
207 if ((unsigned long)i != PACKET_remaining(pkt)) {
208 al = SSL_AD_DECODE_ERROR;
209 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
213 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) {
214 al = SSL_AD_DECRYPT_ERROR;
215 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
220 * Copy the finished so we can use it for renegotiation checks
223 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
224 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
225 s->s3->previous_client_finished_len = i;
227 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
228 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
229 s->s3->previous_server_finished_len = i;
232 return MSG_PROCESS_FINISHED_READING;
234 ssl3_send_alert(s, SSL3_AL_FATAL, al);
235 ossl_statem_set_error(s);
236 return MSG_PROCESS_ERROR;
239 int tls_construct_change_cipher_spec(SSL *s)
243 p = (unsigned char *)s->init_buf->data;
251 unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk)
254 unsigned long l = 3 + SSL_HM_HEADER_LENGTH(s);
256 if (!ssl_add_cert_chain(s, cpk, &l))
259 l -= 3 + SSL_HM_HEADER_LENGTH(s);
260 p = ssl_handshake_start(s);
264 if (!ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE, l)) {
265 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
268 return l + SSL_HM_HEADER_LENGTH(s);
271 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
273 void (*cb) (const SSL *ssl, int type, int val) = NULL;
275 #ifndef OPENSSL_NO_SCTP
276 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
278 ret = dtls_wait_for_dry(s);
279 if (ret != WORK_FINISHED_CONTINUE)
284 /* clean a few things up */
285 ssl3_cleanup_key_block(s);
287 if (!SSL_IS_DTLS(s)) {
289 * We don't do this in DTLS because we may still need the init_buf
290 * in case there are any unexpected retransmits
292 BUF_MEM_free(s->init_buf);
296 ssl_free_wbio_buffer(s);
300 if (!s->server || s->renegotiate == 2) {
301 /* skipped if we just sent a HelloRequest */
306 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
308 s->ctx->stats.sess_accept_good++;
309 s->handshake_func = ossl_statem_accept;
311 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
313 s->ctx->stats.sess_hit++;
315 s->handshake_func = ossl_statem_connect;
316 s->ctx->stats.sess_connect_good++;
319 if (s->info_callback != NULL)
320 cb = s->info_callback;
321 else if (s->ctx->info_callback != NULL)
322 cb = s->ctx->info_callback;
325 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
327 if (SSL_IS_DTLS(s)) {
328 /* done with handshaking */
329 s->d1->handshake_read_seq = 0;
330 s->d1->handshake_write_seq = 0;
331 s->d1->next_handshake_write_seq = 0;
335 return WORK_FINISHED_STOP;
338 int tls_get_message_header(SSL *s, int *mt)
340 /* s->init_num < SSL3_HM_HEADER_LENGTH */
341 int skip_message, i, recvd_type, al;
345 p = (unsigned char *)s->init_buf->data;
348 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
349 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
350 &p[s->init_num], SSL3_HM_HEADER_LENGTH - s->init_num, 0);
352 s->rwstate = SSL_READING;
355 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
357 * A ChangeCipherSpec must be a single byte and may not occur
358 * in the middle of a handshake message.
360 if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) {
361 al = SSL_AD_UNEXPECTED_MESSAGE;
362 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
363 SSL_R_BAD_CHANGE_CIPHER_SPEC);
366 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
368 s->s3->tmp.message_size = i;
370 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
371 al = SSL_AD_UNEXPECTED_MESSAGE;
372 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
380 if (p[0] == SSL3_MT_HELLO_REQUEST)
382 * The server may always send 'Hello Request' messages --
383 * we are doing a handshake anyway now, so ignore them if
384 * their format is correct. Does not count for 'Finished'
387 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
392 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
393 p, SSL3_HM_HEADER_LENGTH, s,
394 s->msg_callback_arg);
396 } while (skip_message);
397 /* s->init_num == SSL3_HM_HEADER_LENGTH */
400 s->s3->tmp.message_type = *(p++);
402 if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
404 * Only happens with SSLv3+ in an SSLv2 backward compatible
408 * Total message size is the remaining record bytes to read
409 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
411 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
412 + SSL3_HM_HEADER_LENGTH;
413 if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
414 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
417 s->s3->tmp.message_size = l;
419 s->init_msg = s->init_buf->data;
420 s->init_num = SSL3_HM_HEADER_LENGTH;
423 /* BUF_MEM_grow takes an 'int' parameter */
424 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
425 al = SSL_AD_ILLEGAL_PARAMETER;
426 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
429 if (l && !BUF_MEM_grow_clean(s->init_buf,
430 (int)l + SSL3_HM_HEADER_LENGTH)) {
431 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
434 s->s3->tmp.message_size = l;
436 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
442 ssl3_send_alert(s, SSL3_AL_FATAL, al);
447 int tls_get_message_body(SSL *s, unsigned long *len)
453 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
454 /* We've already read everything in */
455 *len = (unsigned long)s->init_num;
460 n = s->s3->tmp.message_size - s->init_num;
462 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
463 &p[s->init_num], n, 0);
465 s->rwstate = SSL_READING;
473 #ifndef OPENSSL_NO_NEXTPROTONEG
475 * If receiving Finished, record MAC of prior handshake messages for
476 * Finished verification.
478 if (*s->init_buf->data == SSL3_MT_FINISHED)
482 /* Feed this message into MAC computation. */
483 if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
484 ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num);
486 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
487 (size_t)s->init_num, s, s->msg_callback_arg);
489 ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
490 s->init_num + SSL3_HM_HEADER_LENGTH);
492 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
493 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
494 s->msg_callback_arg);
498 * init_num should never be negative...should probably be declared
501 if (s->init_num < 0) {
502 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
503 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
507 *len = (unsigned long)s->init_num;
511 int ssl_cert_type(X509 *x, EVP_PKEY *pk)
514 (pk = X509_get0_pubkey(x)) == NULL)
517 switch (EVP_PKEY_id(pk)) {
521 return SSL_PKEY_RSA_ENC;
523 return SSL_PKEY_DSA_SIGN;
524 #ifndef OPENSSL_NO_EC
528 #ifndef OPENSSL_NO_GOST
529 case NID_id_GostR3410_2001:
530 return SSL_PKEY_GOST01;
531 case NID_id_GostR3410_2012_256:
532 return SSL_PKEY_GOST12_256;
533 case NID_id_GostR3410_2012_512:
534 return SSL_PKEY_GOST12_512;
539 int ssl_verify_alarm_type(long type)
544 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
545 case X509_V_ERR_UNABLE_TO_GET_CRL:
546 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
547 al = SSL_AD_UNKNOWN_CA;
549 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
550 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
551 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
552 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
553 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
554 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
555 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
556 case X509_V_ERR_CERT_NOT_YET_VALID:
557 case X509_V_ERR_CRL_NOT_YET_VALID:
558 case X509_V_ERR_CERT_UNTRUSTED:
559 case X509_V_ERR_CERT_REJECTED:
560 case X509_V_ERR_HOSTNAME_MISMATCH:
561 case X509_V_ERR_EMAIL_MISMATCH:
562 case X509_V_ERR_IP_ADDRESS_MISMATCH:
563 case X509_V_ERR_DANE_NO_MATCH:
564 case X509_V_ERR_EE_KEY_TOO_SMALL:
565 case X509_V_ERR_CA_KEY_TOO_SMALL:
566 case X509_V_ERR_CA_MD_TOO_WEAK:
567 al = SSL_AD_BAD_CERTIFICATE;
569 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
570 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
571 al = SSL_AD_DECRYPT_ERROR;
573 case X509_V_ERR_CERT_HAS_EXPIRED:
574 case X509_V_ERR_CRL_HAS_EXPIRED:
575 al = SSL_AD_CERTIFICATE_EXPIRED;
577 case X509_V_ERR_CERT_REVOKED:
578 al = SSL_AD_CERTIFICATE_REVOKED;
580 case X509_V_ERR_UNSPECIFIED:
581 case X509_V_ERR_OUT_OF_MEM:
582 case X509_V_ERR_INVALID_CALL:
583 case X509_V_ERR_STORE_LOOKUP:
584 al = SSL_AD_INTERNAL_ERROR;
586 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
587 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
588 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
589 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
590 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
591 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
592 case X509_V_ERR_INVALID_CA:
593 al = SSL_AD_UNKNOWN_CA;
595 case X509_V_ERR_APPLICATION_VERIFICATION:
596 al = SSL_AD_HANDSHAKE_FAILURE;
598 case X509_V_ERR_INVALID_PURPOSE:
599 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
602 al = SSL_AD_CERTIFICATE_UNKNOWN;
608 int ssl_allow_compression(SSL *s)
610 if (s->options & SSL_OP_NO_COMPRESSION)
612 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
615 static int version_cmp(const SSL *s, int a, int b)
617 int dtls = SSL_IS_DTLS(s);
622 return a < b ? -1 : 1;
623 return DTLS_VERSION_LT(a, b) ? -1 : 1;
628 const SSL_METHOD *(*cmeth)(void);
629 const SSL_METHOD *(*smeth)(void);
632 #if TLS_MAX_VERSION != TLS1_2_VERSION
633 # error Code needs update for TLS_method() support beyond TLS1_2_VERSION.
636 static const version_info tls_version_table[] = {
637 #ifndef OPENSSL_NO_TLS1_2
638 { TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method },
640 { TLS1_2_VERSION, NULL, NULL },
642 #ifndef OPENSSL_NO_TLS1_1
643 { TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method },
645 { TLS1_1_VERSION, NULL, NULL },
647 #ifndef OPENSSL_NO_TLS1
648 { TLS1_VERSION, tlsv1_client_method, tlsv1_server_method },
650 { TLS1_VERSION, NULL, NULL },
652 #ifndef OPENSSL_NO_SSL3
653 { SSL3_VERSION, sslv3_client_method, sslv3_server_method },
655 { SSL3_VERSION, NULL, NULL },
660 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
661 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
664 static const version_info dtls_version_table[] = {
665 #ifndef OPENSSL_NO_DTLS1_2
666 { DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method },
668 { DTLS1_2_VERSION, NULL, NULL },
670 #ifndef OPENSSL_NO_DTLS1
671 { DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method },
673 { DTLS1_VERSION, NULL, NULL },
679 * ssl_method_error - Check whether an SSL_METHOD is enabled.
681 * @s: The SSL handle for the candidate method
682 * @method: the intended method.
684 * Returns 0 on success, or an SSL error reason on failure.
686 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
688 int version = method->version;
690 if ((s->min_proto_version != 0 &&
691 version_cmp(s, version, s->min_proto_version) < 0) ||
692 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
693 return SSL_R_VERSION_TOO_LOW;
695 if (s->max_proto_version != 0 &&
696 version_cmp(s, version, s->max_proto_version) > 0)
697 return SSL_R_VERSION_TOO_HIGH;
699 if ((s->options & method->mask) != 0)
700 return SSL_R_UNSUPPORTED_PROTOCOL;
701 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
702 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
703 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
704 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
710 * ssl_version_supported - Check that the specified `version` is supported by
713 * @s: The SSL handle for the candidate method
714 * @version: Protocol version to test against
716 * Returns 1 when supported, otherwise 0
718 int ssl_version_supported(const SSL *s, int version)
720 const version_info *vent;
721 const version_info *table;
723 switch (s->method->version) {
725 /* Version should match method version for non-ANY method */
726 return version_cmp(s, version, s->version) == 0;
727 case TLS_ANY_VERSION:
728 table = tls_version_table;
730 case DTLS_ANY_VERSION:
731 table = dtls_version_table;
736 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
738 if (vent->cmeth != NULL &&
739 version_cmp(s, version, vent->version) == 0 &&
740 ssl_method_error(s, vent->cmeth()) == 0) {
748 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
749 * fallback indication from a client check whether we're using the highest
750 * supported protocol version.
752 * @s server SSL handle.
754 * Returns 1 when using the highest enabled version, 0 otherwise.
756 int ssl_check_version_downgrade(SSL *s)
758 const version_info *vent;
759 const version_info *table;
762 * Check that the current protocol is the highest enabled version
763 * (according to s->ctx->method, as version negotiation may have changed
766 if (s->version == s->ctx->method->version)
770 * Apparently we're using a version-flexible SSL_METHOD (not at its
771 * highest protocol version).
773 if (s->ctx->method->version == TLS_method()->version)
774 table = tls_version_table;
775 else if (s->ctx->method->version == DTLS_method()->version)
776 table = dtls_version_table;
778 /* Unexpected state; fail closed. */
782 for (vent = table; vent->version != 0; ++vent) {
783 if (vent->smeth != NULL &&
784 ssl_method_error(s, vent->smeth()) == 0)
785 return s->version == vent->version;
791 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
792 * protocols, provided the initial (D)TLS method is version-flexible. This
793 * function sanity-checks the proposed value and makes sure the method is
794 * version-flexible, then sets the limit if all is well.
796 * @method_version: The version of the current SSL_METHOD.
797 * @version: the intended limit.
798 * @bound: pointer to limit to be updated.
800 * Returns 1 on success, 0 on failure.
802 int ssl_set_version_bound(int method_version, int version, int *bound)
810 * Restrict TLS methods to TLS protocol versions.
811 * Restrict DTLS methods to DTLS protocol versions.
812 * Note, DTLS version numbers are decreasing, use comparison macros.
814 * Note that for both lower-bounds we use explicit versions, not
815 * (D)TLS_MIN_VERSION. This is because we don't want to break user
816 * configurations. If the MIN (supported) version ever rises, the user's
817 * "floor" remains valid even if no longer available. We don't expect the
818 * MAX ceiling to ever get lower, so making that variable makes sense.
820 switch (method_version) {
823 * XXX For fixed version methods, should we always fail and not set any
824 * bounds, always succeed and not set any bounds, or set the bounds and
825 * arrange to fail later if they are not met? At present fixed-version
826 * methods are not subject to controls that disable individual protocol
831 case TLS_ANY_VERSION:
832 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
836 case DTLS_ANY_VERSION:
837 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
838 DTLS_VERSION_LT(version, DTLS1_VERSION))
848 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
849 * client HELLO is received to select the final server protocol version and
850 * the version specific method.
852 * @s: server SSL handle.
854 * Returns 0 on success or an SSL error reason number on failure.
856 int ssl_choose_server_version(SSL *s)
859 * With version-flexible methods we have an initial state with:
861 * s->method->version == (D)TLS_ANY_VERSION,
862 * s->version == (D)TLS_MAX_VERSION.
864 * So we detect version-flexible methods via the method version, not the
867 int server_version = s->method->version;
868 int client_version = s->client_version;
869 const version_info *vent;
870 const version_info *table;
873 switch (server_version) {
875 if (version_cmp(s, client_version, s->version) < 0)
876 return SSL_R_WRONG_SSL_VERSION;
878 * If this SSL handle is not from a version flexible method we don't
879 * (and never did) check min/max FIPS or Suite B constraints. Hope
880 * that's OK. It is up to the caller to not choose fixed protocol
881 * versions they don't want. If not, then easy to fix, just return
882 * ssl_method_error(s, s->method)
885 case TLS_ANY_VERSION:
886 table = tls_version_table;
888 case DTLS_ANY_VERSION:
889 table = dtls_version_table;
893 for (vent = table; vent->version != 0; ++vent) {
894 const SSL_METHOD *method;
896 if (vent->smeth == NULL ||
897 version_cmp(s, client_version, vent->version) < 0)
899 method = vent->smeth();
900 if (ssl_method_error(s, method) == 0) {
901 s->version = vent->version;
907 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
911 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
912 * server HELLO is received to select the final client protocol version and
913 * the version specific method.
915 * @s: client SSL handle.
916 * @version: The proposed version from the server's HELLO.
918 * Returns 0 on success or an SSL error reason number on failure.
920 int ssl_choose_client_version(SSL *s, int version)
922 const version_info *vent;
923 const version_info *table;
925 switch (s->method->version) {
927 if (version != s->version)
928 return SSL_R_WRONG_SSL_VERSION;
930 * If this SSL handle is not from a version flexible method we don't
931 * (and never did) check min/max, FIPS or Suite B constraints. Hope
932 * that's OK. It is up to the caller to not choose fixed protocol
933 * versions they don't want. If not, then easy to fix, just return
934 * ssl_method_error(s, s->method)
937 case TLS_ANY_VERSION:
938 table = tls_version_table;
940 case DTLS_ANY_VERSION:
941 table = dtls_version_table;
945 for (vent = table; vent->version != 0; ++vent) {
946 const SSL_METHOD *method;
949 if (version != vent->version)
951 if (vent->cmeth == NULL)
953 method = vent->cmeth();
954 err = ssl_method_error(s, method);
958 s->version = version;
962 return SSL_R_UNSUPPORTED_PROTOCOL;
966 * ssl_get_client_min_max_version - get minimum and maximum client version
967 * @s: The SSL connection
968 * @min_version: The minimum supported version
969 * @max_version: The maximum supported version
971 * Work out what version we should be using for the initial ClientHello if the
972 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
973 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
974 * or FIPS_mode() constraints and any floor imposed by the security level here,
975 * so we don't advertise the wrong protocol version to only reject the outcome later.
977 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
978 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
979 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
981 * Returns 0 on success or an SSL error reason number on failure. On failure
982 * min_version and max_version will also be set to 0.
984 int ssl_get_client_min_max_version(const SSL *s, int *min_version, int *max_version)
988 const SSL_METHOD *single = NULL;
989 const SSL_METHOD *method;
990 const version_info *table;
991 const version_info *vent;
993 switch (s->method->version) {
996 * If this SSL handle is not from a version flexible method we don't
997 * (and never did) check min/max FIPS or Suite B constraints. Hope
998 * that's OK. It is up to the caller to not choose fixed protocol
999 * versions they don't want. If not, then easy to fix, just return
1000 * ssl_method_error(s, s->method)
1002 *min_version = *max_version = s->version;
1004 case TLS_ANY_VERSION:
1005 table = tls_version_table;
1007 case DTLS_ANY_VERSION:
1008 table = dtls_version_table;
1013 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1014 * below X enabled. This is required in order to maintain the "version
1015 * capability" vector contiguous. Any versions with a NULL client method
1016 * (protocol version client is disabled at compile-time) is also a "hole".
1018 * Our initial state is hole == 1, version == 0. That is, versions above
1019 * the first version in the method table are disabled (a "hole" above
1020 * the valid protocol entries) and we don't have a selected version yet.
1022 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1023 * the selected version, and the method becomes a candidate "single"
1024 * method. We're no longer in a hole, so "hole" becomes 0.
1026 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1027 * as we support a contiguous range of at least two methods. If we hit
1028 * a disabled method, then hole becomes true again, but nothing else
1029 * changes yet, because all the remaining methods may be disabled too.
1030 * If we again hit an enabled method after the new hole, it becomes
1031 * selected, as we start from scratch.
1033 *min_version = version = 0;
1035 for (vent = table; vent->version != 0; ++vent) {
1037 * A table entry with a NULL client method is still a hole in the
1038 * "version capability" vector.
1040 if (vent->cmeth == NULL) {
1044 method = vent->cmeth();
1045 if (ssl_method_error(s, method) != 0) {
1049 *min_version = method->version;
1051 version = (single = method)->version;
1052 *min_version = version;
1057 *max_version = version;
1059 /* Fail if everything is disabled */
1061 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1067 * ssl_set_client_hello_version - Work out what version we should be using for
1068 * the initial ClientHello.
1070 * @s: client SSL handle.
1072 * Returns 0 on success or an SSL error reason number on failure.
1074 int ssl_set_client_hello_version(SSL *s)
1076 int ver_min, ver_max, ret;
1078 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1083 s->client_version = s->version = ver_max;