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/rand.h>
23 #include <openssl/objects.h>
24 #include <openssl/evp.h>
25 #include <openssl/x509.h>
28 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
29 * SSL3_RT_CHANGE_CIPHER_SPEC)
31 int ssl3_do_write(SSL *s, int type)
35 ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
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 ssl3_finish_mac(s, (unsigned char *)&s->init_buf->data[s->init_off],
47 if (ret == s->init_num) {
49 s->msg_callback(1, s->version, type, s->init_buf->data,
50 (size_t)(s->init_off + s->init_num), s,
59 int tls_construct_finished(SSL *s, const char *sender, int slen)
65 p = ssl_handshake_start(s);
67 i = s->method->ssl3_enc->final_finish_mac(s,
69 s->s3->tmp.finish_md);
72 s->s3->tmp.finish_md_len = i;
73 memcpy(p, s->s3->tmp.finish_md, i);
77 * Copy the finished so we can use it for renegotiation checks
80 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
81 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
82 s->s3->previous_client_finished_len = i;
84 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
85 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
86 s->s3->previous_server_finished_len = i;
89 if (!ssl_set_handshake_header(s, SSL3_MT_FINISHED, l)) {
90 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
97 #ifndef OPENSSL_NO_NEXTPROTONEG
99 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
102 static void ssl3_take_mac(SSL *s)
107 * If no new cipher setup return immediately: other functions will set
108 * the appropriate error.
110 if (s->s3->tmp.new_cipher == NULL)
113 sender = s->method->ssl3_enc->server_finished_label;
114 slen = s->method->ssl3_enc->server_finished_label_len;
116 sender = s->method->ssl3_enc->client_finished_label;
117 slen = s->method->ssl3_enc->client_finished_label_len;
120 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
123 s->s3->tmp.peer_finish_md);
127 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
132 remain = PACKET_remaining(pkt);
134 * 'Change Cipher Spec' is just a single byte, which should already have
135 * been consumed by ssl_get_message() so there should be no bytes left,
136 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
138 if (SSL_IS_DTLS(s)) {
139 if ((s->version == DTLS1_BAD_VER
140 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
141 || (s->version != DTLS1_BAD_VER
142 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
143 al = SSL_AD_ILLEGAL_PARAMETER;
144 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
145 SSL_R_BAD_CHANGE_CIPHER_SPEC);
150 al = SSL_AD_ILLEGAL_PARAMETER;
151 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
152 SSL_R_BAD_CHANGE_CIPHER_SPEC);
157 /* Check we have a cipher to change to */
158 if (s->s3->tmp.new_cipher == NULL) {
159 al = SSL_AD_UNEXPECTED_MESSAGE;
160 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
164 s->s3->change_cipher_spec = 1;
165 if (!ssl3_do_change_cipher_spec(s)) {
166 al = SSL_AD_INTERNAL_ERROR;
167 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
171 if (SSL_IS_DTLS(s)) {
172 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
174 if (s->version == DTLS1_BAD_VER)
175 s->d1->handshake_read_seq++;
177 #ifndef OPENSSL_NO_SCTP
179 * Remember that a CCS has been received, so that an old key of
180 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
183 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
187 return MSG_PROCESS_CONTINUE_READING;
189 ssl3_send_alert(s, SSL3_AL_FATAL, al);
190 ossl_statem_set_error(s);
191 return MSG_PROCESS_ERROR;
194 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
198 /* If this occurs, we have missed a message */
199 if (!s->s3->change_cipher_spec) {
200 al = SSL_AD_UNEXPECTED_MESSAGE;
201 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
204 s->s3->change_cipher_spec = 0;
206 i = s->s3->tmp.peer_finish_md_len;
208 if ((unsigned long)i != PACKET_remaining(pkt)) {
209 al = SSL_AD_DECODE_ERROR;
210 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
214 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) {
215 al = SSL_AD_DECRYPT_ERROR;
216 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
221 * Copy the finished so we can use it for renegotiation checks
224 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
225 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
226 s->s3->previous_client_finished_len = i;
228 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
229 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
230 s->s3->previous_server_finished_len = i;
233 return MSG_PROCESS_FINISHED_READING;
235 ssl3_send_alert(s, SSL3_AL_FATAL, al);
236 ossl_statem_set_error(s);
237 return MSG_PROCESS_ERROR;
240 int tls_construct_change_cipher_spec(SSL *s)
244 p = (unsigned char *)s->init_buf->data;
252 unsigned long ssl3_output_cert_chain(SSL *s, CERT_PKEY *cpk)
255 unsigned long l = 3 + SSL_HM_HEADER_LENGTH(s);
257 if (!ssl_add_cert_chain(s, cpk, &l))
260 l -= 3 + SSL_HM_HEADER_LENGTH(s);
261 p = ssl_handshake_start(s);
265 if (!ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE, l)) {
266 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
269 return l + SSL_HM_HEADER_LENGTH(s);
272 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
274 void (*cb) (const SSL *ssl, int type, int val) = NULL;
276 #ifndef OPENSSL_NO_SCTP
277 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
279 ret = dtls_wait_for_dry(s);
280 if (ret != WORK_FINISHED_CONTINUE)
285 /* clean a few things up */
286 ssl3_cleanup_key_block(s);
288 if (!SSL_IS_DTLS(s)) {
290 * We don't do this in DTLS because we may still need the init_buf
291 * in case there are any unexpected retransmits
293 BUF_MEM_free(s->init_buf);
297 ssl_free_wbio_buffer(s);
301 if (!s->server || s->renegotiate == 2) {
302 /* skipped if we just sent a HelloRequest */
307 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
309 s->ctx->stats.sess_accept_good++;
310 s->handshake_func = ossl_statem_accept;
312 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
314 s->ctx->stats.sess_hit++;
316 s->handshake_func = ossl_statem_connect;
317 s->ctx->stats.sess_connect_good++;
320 if (s->info_callback != NULL)
321 cb = s->info_callback;
322 else if (s->ctx->info_callback != NULL)
323 cb = s->ctx->info_callback;
326 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
328 if (SSL_IS_DTLS(s)) {
329 /* done with handshaking */
330 s->d1->handshake_read_seq = 0;
331 s->d1->handshake_write_seq = 0;
332 s->d1->next_handshake_write_seq = 0;
336 return WORK_FINISHED_STOP;
339 int tls_get_message_header(SSL *s, int *mt)
341 /* s->init_num < SSL3_HM_HEADER_LENGTH */
342 int skip_message, i, recvd_type, al;
346 p = (unsigned char *)s->init_buf->data;
349 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
350 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
351 &p[s->init_num], SSL3_HM_HEADER_LENGTH - s->init_num, 0);
353 s->rwstate = SSL_READING;
356 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
357 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
359 s->s3->tmp.message_size = i;
361 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
362 al = SSL_AD_UNEXPECTED_MESSAGE;
363 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
371 if (p[0] == SSL3_MT_HELLO_REQUEST)
373 * The server may always send 'Hello Request' messages --
374 * we are doing a handshake anyway now, so ignore them if
375 * their format is correct. Does not count for 'Finished'
378 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
383 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
384 p, SSL3_HM_HEADER_LENGTH, s,
385 s->msg_callback_arg);
387 } while (skip_message);
388 /* s->init_num == SSL3_HM_HEADER_LENGTH */
391 s->s3->tmp.message_type = *(p++);
393 if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
395 * Only happens with SSLv3+ in an SSLv2 backward compatible
399 * Total message size is the remaining record bytes to read
400 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
402 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
403 + SSL3_HM_HEADER_LENGTH;
404 if (l && !BUF_MEM_grow_clean(s->init_buf, (int)l)) {
405 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
408 s->s3->tmp.message_size = l;
410 s->init_msg = s->init_buf->data;
411 s->init_num = SSL3_HM_HEADER_LENGTH;
414 /* BUF_MEM_grow takes an 'int' parameter */
415 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
416 al = SSL_AD_ILLEGAL_PARAMETER;
417 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
420 if (l && !BUF_MEM_grow_clean(s->init_buf,
421 (int)l + SSL3_HM_HEADER_LENGTH)) {
422 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, ERR_R_BUF_LIB);
425 s->s3->tmp.message_size = l;
427 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
433 ssl3_send_alert(s, SSL3_AL_FATAL, al);
438 int tls_get_message_body(SSL *s, unsigned long *len)
444 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
445 /* We've already read everything in */
446 *len = (unsigned long)s->init_num;
451 n = s->s3->tmp.message_size - s->init_num;
453 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
454 &p[s->init_num], n, 0);
456 s->rwstate = SSL_READING;
464 #ifndef OPENSSL_NO_NEXTPROTONEG
466 * If receiving Finished, record MAC of prior handshake messages for
467 * Finished verification.
469 if (*s->init_buf->data == SSL3_MT_FINISHED)
473 /* Feed this message into MAC computation. */
474 if(RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
475 ssl3_finish_mac(s, (unsigned char *)s->init_buf->data, s->init_num);
477 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
478 (size_t)s->init_num, s, s->msg_callback_arg);
480 ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
481 s->init_num + SSL3_HM_HEADER_LENGTH);
483 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
484 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
485 s->msg_callback_arg);
489 * init_num should never be negative...should probably be declared
492 if (s->init_num < 0) {
493 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
494 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
498 *len = (unsigned long)s->init_num;
502 int ssl_cert_type(X509 *x, EVP_PKEY *pk)
505 (pk = X509_get0_pubkey(x)) == NULL)
508 switch (EVP_PKEY_id(pk)) {
512 return SSL_PKEY_RSA_ENC;
514 return SSL_PKEY_DSA_SIGN;
515 #ifndef OPENSSL_NO_EC
519 #ifndef OPENSSL_NO_GOST
520 case NID_id_GostR3410_2001:
521 return SSL_PKEY_GOST01;
522 case NID_id_GostR3410_2012_256:
523 return SSL_PKEY_GOST12_256;
524 case NID_id_GostR3410_2012_512:
525 return SSL_PKEY_GOST12_512;
530 int ssl_verify_alarm_type(long type)
535 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
536 case X509_V_ERR_UNABLE_TO_GET_CRL:
537 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
538 al = SSL_AD_UNKNOWN_CA;
540 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
541 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
542 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
543 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
544 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
545 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
546 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
547 case X509_V_ERR_CERT_NOT_YET_VALID:
548 case X509_V_ERR_CRL_NOT_YET_VALID:
549 case X509_V_ERR_CERT_UNTRUSTED:
550 case X509_V_ERR_CERT_REJECTED:
551 al = SSL_AD_BAD_CERTIFICATE;
553 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
554 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
555 al = SSL_AD_DECRYPT_ERROR;
557 case X509_V_ERR_CERT_HAS_EXPIRED:
558 case X509_V_ERR_CRL_HAS_EXPIRED:
559 al = SSL_AD_CERTIFICATE_EXPIRED;
561 case X509_V_ERR_CERT_REVOKED:
562 al = SSL_AD_CERTIFICATE_REVOKED;
564 case X509_V_ERR_OUT_OF_MEM:
565 al = SSL_AD_INTERNAL_ERROR;
567 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
568 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
569 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
570 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
571 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
572 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
573 case X509_V_ERR_INVALID_CA:
574 al = SSL_AD_UNKNOWN_CA;
576 case X509_V_ERR_APPLICATION_VERIFICATION:
577 al = SSL_AD_HANDSHAKE_FAILURE;
579 case X509_V_ERR_INVALID_PURPOSE:
580 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
583 al = SSL_AD_CERTIFICATE_UNKNOWN;
589 int ssl_allow_compression(SSL *s)
591 if (s->options & SSL_OP_NO_COMPRESSION)
593 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
596 static int version_cmp(const SSL *s, int a, int b)
598 int dtls = SSL_IS_DTLS(s);
603 return a < b ? -1 : 1;
604 return DTLS_VERSION_LT(a, b) ? -1 : 1;
609 const SSL_METHOD *(*cmeth)(void);
610 const SSL_METHOD *(*smeth)(void);
613 #if TLS_MAX_VERSION != TLS1_2_VERSION
614 # error Code needs update for TLS_method() support beyond TLS1_2_VERSION.
617 static const version_info tls_version_table[] = {
618 #ifndef OPENSSL_NO_TLS1_2
619 { TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method },
621 { TLS1_2_VERSION, NULL, NULL },
623 #ifndef OPENSSL_NO_TLS1_1
624 { TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method },
626 { TLS1_1_VERSION, NULL, NULL },
628 #ifndef OPENSSL_NO_TLS1
629 { TLS1_VERSION, tlsv1_client_method, tlsv1_server_method },
631 { TLS1_VERSION, NULL, NULL },
633 #ifndef OPENSSL_NO_SSL3
634 { SSL3_VERSION, sslv3_client_method, sslv3_server_method },
636 { SSL3_VERSION, NULL, NULL },
641 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
642 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
645 static const version_info dtls_version_table[] = {
646 #ifndef OPENSSL_NO_DTLS1_2
647 { DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method },
649 { DTLS1_2_VERSION, NULL, NULL },
651 #ifndef OPENSSL_NO_DTLS1
652 { DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method },
654 { DTLS1_VERSION, NULL, NULL },
660 * ssl_method_error - Check whether an SSL_METHOD is enabled.
662 * @s: The SSL handle for the candidate method
663 * @method: the intended method.
665 * Returns 0 on success, or an SSL error reason on failure.
667 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
669 int version = method->version;
671 if ((s->min_proto_version != 0 &&
672 version_cmp(s, version, s->min_proto_version) < 0) ||
673 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
674 return SSL_R_VERSION_TOO_LOW;
676 if (s->max_proto_version != 0 &&
677 version_cmp(s, version, s->max_proto_version) > 0)
678 return SSL_R_VERSION_TOO_HIGH;
680 if ((s->options & method->mask) != 0)
681 return SSL_R_UNSUPPORTED_PROTOCOL;
682 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
683 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
684 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
685 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
691 * ssl_version_supported - Check that the specified `version` is supported by
694 * @s: The SSL handle for the candidate method
695 * @version: Protocol version to test against
697 * Returns 1 when supported, otherwise 0
699 int ssl_version_supported(const SSL *s, int version)
701 const version_info *vent;
702 const version_info *table;
704 switch (s->method->version) {
706 /* Version should match method version for non-ANY method */
707 return version_cmp(s, version, s->version) == 0;
708 case TLS_ANY_VERSION:
709 table = tls_version_table;
711 case DTLS_ANY_VERSION:
712 table = dtls_version_table;
717 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
719 if (vent->cmeth != NULL &&
720 version_cmp(s, version, vent->version) == 0 &&
721 ssl_method_error(s, vent->cmeth()) == 0) {
729 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
730 * fallback indication from a client check whether we're using the highest
731 * supported protocol version.
733 * @s server SSL handle.
735 * Returns 1 when using the highest enabled version, 0 otherwise.
737 int ssl_check_version_downgrade(SSL *s)
739 const version_info *vent;
740 const version_info *table;
743 * Check that the current protocol is the highest enabled version
744 * (according to s->ctx->method, as version negotiation may have changed
747 if (s->version == s->ctx->method->version)
751 * Apparently we're using a version-flexible SSL_METHOD (not at its
752 * highest protocol version).
754 if (s->ctx->method->version == TLS_method()->version)
755 table = tls_version_table;
756 else if (s->ctx->method->version == DTLS_method()->version)
757 table = dtls_version_table;
759 /* Unexpected state; fail closed. */
763 for (vent = table; vent->version != 0; ++vent) {
764 if (vent->smeth != NULL &&
765 ssl_method_error(s, vent->smeth()) == 0)
766 return s->version == vent->version;
772 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
773 * protocols, provided the initial (D)TLS method is version-flexible. This
774 * function sanity-checks the proposed value and makes sure the method is
775 * version-flexible, then sets the limit if all is well.
777 * @method_version: The version of the current SSL_METHOD.
778 * @version: the intended limit.
779 * @bound: pointer to limit to be updated.
781 * Returns 1 on success, 0 on failure.
783 int ssl_set_version_bound(int method_version, int version, int *bound)
791 * Restrict TLS methods to TLS protocol versions.
792 * Restrict DTLS methods to DTLS protocol versions.
793 * Note, DTLS version numbers are decreasing, use comparison macros.
795 * Note that for both lower-bounds we use explicit versions, not
796 * (D)TLS_MIN_VERSION. This is because we don't want to break user
797 * configurations. If the MIN (supported) version ever rises, the user's
798 * "floor" remains valid even if no longer available. We don't expect the
799 * MAX ceiling to ever get lower, so making that variable makes sense.
801 switch (method_version) {
804 * XXX For fixed version methods, should we always fail and not set any
805 * bounds, always succeed and not set any bounds, or set the bounds and
806 * arrange to fail later if they are not met? At present fixed-version
807 * methods are not subject to controls that disable individual protocol
812 case TLS_ANY_VERSION:
813 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
817 case DTLS_ANY_VERSION:
818 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
819 DTLS_VERSION_LT(version, DTLS1_VERSION))
829 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
830 * client HELLO is received to select the final server protocol version and
831 * the version specific method.
833 * @s: server SSL handle.
835 * Returns 0 on success or an SSL error reason number on failure.
837 int ssl_choose_server_version(SSL *s)
840 * With version-flexible methods we have an initial state with:
842 * s->method->version == (D)TLS_ANY_VERSION,
843 * s->version == (D)TLS_MAX_VERSION.
845 * So we detect version-flexible methods via the method version, not the
848 int server_version = s->method->version;
849 int client_version = s->client_version;
850 const version_info *vent;
851 const version_info *table;
854 switch (server_version) {
856 if (version_cmp(s, client_version, s->version) < 0)
857 return SSL_R_WRONG_SSL_VERSION;
859 * If this SSL handle is not from a version flexible method we don't
860 * (and never did) check min/max FIPS or Suite B constraints. Hope
861 * that's OK. It is up to the caller to not choose fixed protocol
862 * versions they don't want. If not, then easy to fix, just return
863 * ssl_method_error(s, s->method)
866 case TLS_ANY_VERSION:
867 table = tls_version_table;
869 case DTLS_ANY_VERSION:
870 table = dtls_version_table;
874 for (vent = table; vent->version != 0; ++vent) {
875 const SSL_METHOD *method;
877 if (vent->smeth == NULL ||
878 version_cmp(s, client_version, vent->version) < 0)
880 method = vent->smeth();
881 if (ssl_method_error(s, method) == 0) {
882 s->version = vent->version;
888 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
892 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
893 * server HELLO is received to select the final client protocol version and
894 * the version specific method.
896 * @s: client SSL handle.
897 * @version: The proposed version from the server's HELLO.
899 * Returns 0 on success or an SSL error reason number on failure.
901 int ssl_choose_client_version(SSL *s, int version)
903 const version_info *vent;
904 const version_info *table;
906 switch (s->method->version) {
908 if (version != s->version)
909 return SSL_R_WRONG_SSL_VERSION;
911 * If this SSL handle is not from a version flexible method we don't
912 * (and never did) check min/max, FIPS or Suite B constraints. Hope
913 * that's OK. It is up to the caller to not choose fixed protocol
914 * versions they don't want. If not, then easy to fix, just return
915 * ssl_method_error(s, s->method)
918 case TLS_ANY_VERSION:
919 table = tls_version_table;
921 case DTLS_ANY_VERSION:
922 table = dtls_version_table;
926 for (vent = table; vent->version != 0; ++vent) {
927 const SSL_METHOD *method;
930 if (version != vent->version)
932 if (vent->cmeth == NULL)
934 method = vent->cmeth();
935 err = ssl_method_error(s, method);
939 s->version = version;
943 return SSL_R_UNSUPPORTED_PROTOCOL;
947 * ssl_get_client_min_max_version - get minimum and maximum client version
948 * @s: The SSL connection
949 * @min_version: The minimum supported version
950 * @max_version: The maximum supported version
952 * Work out what version we should be using for the initial ClientHello if the
953 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
954 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
955 * or FIPS_mode() constraints and any floor imposed by the security level here,
956 * so we don't advertise the wrong protocol version to only reject the outcome later.
958 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
959 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
960 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
962 * Returns 0 on success or an SSL error reason number on failure. On failure
963 * min_version and max_version will also be set to 0.
965 int ssl_get_client_min_max_version(const SSL *s, int *min_version, int *max_version)
969 const SSL_METHOD *single = NULL;
970 const SSL_METHOD *method;
971 const version_info *table;
972 const version_info *vent;
974 switch (s->method->version) {
977 * If this SSL handle is not from a version flexible method we don't
978 * (and never did) check min/max FIPS or Suite B constraints. Hope
979 * that's OK. It is up to the caller to not choose fixed protocol
980 * versions they don't want. If not, then easy to fix, just return
981 * ssl_method_error(s, s->method)
983 *min_version = *max_version = s->version;
985 case TLS_ANY_VERSION:
986 table = tls_version_table;
988 case DTLS_ANY_VERSION:
989 table = dtls_version_table;
994 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
995 * below X enabled. This is required in order to maintain the "version
996 * capability" vector contiguous. Any versions with a NULL client method
997 * (protocol version client is disabled at compile-time) is also a "hole".
999 * Our initial state is hole == 1, version == 0. That is, versions above
1000 * the first version in the method table are disabled (a "hole" above
1001 * the valid protocol entries) and we don't have a selected version yet.
1003 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1004 * the selected version, and the method becomes a candidate "single"
1005 * method. We're no longer in a hole, so "hole" becomes 0.
1007 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1008 * as we support a contiguous range of at least two methods. If we hit
1009 * a disabled method, then hole becomes true again, but nothing else
1010 * changes yet, because all the remaining methods may be disabled too.
1011 * If we again hit an enabled method after the new hole, it becomes
1012 * selected, as we start from scratch.
1014 *min_version = version = 0;
1016 for (vent = table; vent->version != 0; ++vent) {
1018 * A table entry with a NULL client method is still a hole in the
1019 * "version capability" vector.
1021 if (vent->cmeth == NULL) {
1025 method = vent->cmeth();
1026 if (ssl_method_error(s, method) != 0) {
1030 *min_version = method->version;
1032 version = (single = method)->version;
1033 *min_version = version;
1038 *max_version = version;
1040 /* Fail if everything is disabled */
1042 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1048 * ssl_set_client_hello_version - Work out what version we should be using for
1049 * the initial ClientHello.
1051 * @s: client SSL handle.
1053 * Returns 0 on success or an SSL error reason number on failure.
1055 int ssl_set_client_hello_version(SSL *s)
1057 int ver_min, ver_max, ret;
1059 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1064 s->client_version = s->version = ver_max;