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 i = s->method->ssl3_enc->final_finish_mac(s,
80 s->s3->tmp.finish_md);
82 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
86 s->s3->tmp.finish_md_len = i;
88 if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, i)) {
89 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
94 * Copy the finished so we can use it for renegotiation checks
97 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
98 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
99 s->s3->previous_client_finished_len = i;
101 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
102 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
103 s->s3->previous_server_finished_len = i;
108 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
112 #ifndef OPENSSL_NO_NEXTPROTONEG
114 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
117 static void ssl3_take_mac(SSL *s)
122 * If no new cipher setup return immediately: other functions will set
123 * the appropriate error.
125 if (s->s3->tmp.new_cipher == NULL)
128 sender = s->method->ssl3_enc->server_finished_label;
129 slen = s->method->ssl3_enc->server_finished_label_len;
131 sender = s->method->ssl3_enc->client_finished_label;
132 slen = s->method->ssl3_enc->client_finished_label_len;
135 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
138 s->s3->tmp.peer_finish_md);
142 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
147 remain = PACKET_remaining(pkt);
149 * 'Change Cipher Spec' is just a single byte, which should already have
150 * been consumed by ssl_get_message() so there should be no bytes left,
151 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
153 if (SSL_IS_DTLS(s)) {
154 if ((s->version == DTLS1_BAD_VER
155 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
156 || (s->version != DTLS1_BAD_VER
157 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
158 al = SSL_AD_ILLEGAL_PARAMETER;
159 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
160 SSL_R_BAD_CHANGE_CIPHER_SPEC);
165 al = SSL_AD_ILLEGAL_PARAMETER;
166 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
167 SSL_R_BAD_CHANGE_CIPHER_SPEC);
172 /* Check we have a cipher to change to */
173 if (s->s3->tmp.new_cipher == NULL) {
174 al = SSL_AD_UNEXPECTED_MESSAGE;
175 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
179 s->s3->change_cipher_spec = 1;
180 if (!ssl3_do_change_cipher_spec(s)) {
181 al = SSL_AD_INTERNAL_ERROR;
182 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
186 if (SSL_IS_DTLS(s)) {
187 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
189 if (s->version == DTLS1_BAD_VER)
190 s->d1->handshake_read_seq++;
192 #ifndef OPENSSL_NO_SCTP
194 * Remember that a CCS has been received, so that an old key of
195 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
198 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
202 return MSG_PROCESS_CONTINUE_READING;
204 ssl3_send_alert(s, SSL3_AL_FATAL, al);
205 ossl_statem_set_error(s);
206 return MSG_PROCESS_ERROR;
209 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
213 /* If this occurs, we have missed a message */
214 if (!s->s3->change_cipher_spec) {
215 al = SSL_AD_UNEXPECTED_MESSAGE;
216 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
219 s->s3->change_cipher_spec = 0;
221 i = s->s3->tmp.peer_finish_md_len;
223 if ((unsigned long)i != PACKET_remaining(pkt)) {
224 al = SSL_AD_DECODE_ERROR;
225 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
229 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md, i) != 0) {
230 al = SSL_AD_DECRYPT_ERROR;
231 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
236 * Copy the finished so we can use it for renegotiation checks
239 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
240 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md, i);
241 s->s3->previous_client_finished_len = i;
243 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
244 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md, i);
245 s->s3->previous_server_finished_len = i;
248 return MSG_PROCESS_FINISHED_READING;
250 ssl3_send_alert(s, SSL3_AL_FATAL, al);
251 ossl_statem_set_error(s);
252 return MSG_PROCESS_ERROR;
255 int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
257 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) {
258 SSLerr(SSL_F_TLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
259 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
269 unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk)
271 if (!WPACKET_start_sub_packet_u24(pkt)
272 || !ssl_add_cert_chain(s, pkt, cpk)
273 || !WPACKET_close(pkt)) {
274 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
280 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
282 void (*cb) (const SSL *ssl, int type, int val) = NULL;
284 #ifndef OPENSSL_NO_SCTP
285 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
287 ret = dtls_wait_for_dry(s);
288 if (ret != WORK_FINISHED_CONTINUE)
293 /* clean a few things up */
294 ssl3_cleanup_key_block(s);
296 if (!SSL_IS_DTLS(s)) {
298 * We don't do this in DTLS because we may still need the init_buf
299 * in case there are any unexpected retransmits
301 BUF_MEM_free(s->init_buf);
305 ssl_free_wbio_buffer(s);
309 if (!s->server || s->renegotiate == 2) {
310 /* skipped if we just sent a HelloRequest */
315 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
317 s->ctx->stats.sess_accept_good++;
318 s->handshake_func = ossl_statem_accept;
320 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
322 s->ctx->stats.sess_hit++;
324 s->handshake_func = ossl_statem_connect;
325 s->ctx->stats.sess_connect_good++;
328 if (s->info_callback != NULL)
329 cb = s->info_callback;
330 else if (s->ctx->info_callback != NULL)
331 cb = s->ctx->info_callback;
334 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
336 if (SSL_IS_DTLS(s)) {
337 /* done with handshaking */
338 s->d1->handshake_read_seq = 0;
339 s->d1->handshake_write_seq = 0;
340 s->d1->next_handshake_write_seq = 0;
341 dtls1_clear_received_buffer(s);
345 return WORK_FINISHED_STOP;
348 int tls_get_message_header(SSL *s, int *mt)
350 /* s->init_num < SSL3_HM_HEADER_LENGTH */
351 int skip_message, i, recvd_type, al;
355 p = (unsigned char *)s->init_buf->data;
358 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
359 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
361 SSL3_HM_HEADER_LENGTH - s->init_num,
364 s->rwstate = SSL_READING;
367 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
369 * A ChangeCipherSpec must be a single byte and may not occur
370 * in the middle of a handshake message.
372 if (s->init_num != 0 || i != 1 || p[0] != SSL3_MT_CCS) {
373 al = SSL_AD_UNEXPECTED_MESSAGE;
374 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
375 SSL_R_BAD_CHANGE_CIPHER_SPEC);
378 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
380 s->s3->tmp.message_size = i;
382 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
383 al = SSL_AD_UNEXPECTED_MESSAGE;
384 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
392 if (p[0] == SSL3_MT_HELLO_REQUEST)
394 * The server may always send 'Hello Request' messages --
395 * we are doing a handshake anyway now, so ignore them if
396 * their format is correct. Does not count for 'Finished'
399 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
404 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
405 p, SSL3_HM_HEADER_LENGTH, s,
406 s->msg_callback_arg);
408 } while (skip_message);
409 /* s->init_num == SSL3_HM_HEADER_LENGTH */
412 s->s3->tmp.message_type = *(p++);
414 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
416 * Only happens with SSLv3+ in an SSLv2 backward compatible
419 * Total message size is the remaining record bytes to read
420 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
422 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
423 + SSL3_HM_HEADER_LENGTH;
424 s->s3->tmp.message_size = l;
426 s->init_msg = s->init_buf->data;
427 s->init_num = SSL3_HM_HEADER_LENGTH;
430 /* BUF_MEM_grow takes an 'int' parameter */
431 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
432 al = SSL_AD_ILLEGAL_PARAMETER;
433 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
436 s->s3->tmp.message_size = l;
438 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
444 ssl3_send_alert(s, SSL3_AL_FATAL, al);
448 int tls_get_message_body(SSL *s, unsigned long *len)
454 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
455 /* We've already read everything in */
456 *len = (unsigned long)s->init_num;
461 n = s->s3->tmp.message_size - s->init_num;
463 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
464 &p[s->init_num], n, 0);
466 s->rwstate = SSL_READING;
474 #ifndef OPENSSL_NO_NEXTPROTONEG
476 * If receiving Finished, record MAC of prior handshake messages for
477 * Finished verification.
479 if (*s->init_buf->data == SSL3_MT_FINISHED)
483 /* Feed this message into MAC computation. */
484 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
485 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
487 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
488 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
493 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
494 (size_t)s->init_num, s, s->msg_callback_arg);
496 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
497 s->init_num + SSL3_HM_HEADER_LENGTH)) {
498 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
499 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
504 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
505 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
506 s->msg_callback_arg);
510 * init_num should never be negative...should probably be declared
513 if (s->init_num < 0) {
514 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_INTERNAL_ERROR);
515 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
519 *len = (unsigned long)s->init_num;
523 int ssl_cert_type(const X509 *x, const EVP_PKEY *pk)
525 if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL)
528 switch (EVP_PKEY_id(pk)) {
532 return SSL_PKEY_RSA_ENC;
534 return SSL_PKEY_DSA_SIGN;
535 #ifndef OPENSSL_NO_EC
539 #ifndef OPENSSL_NO_GOST
540 case NID_id_GostR3410_2001:
541 return SSL_PKEY_GOST01;
542 case NID_id_GostR3410_2012_256:
543 return SSL_PKEY_GOST12_256;
544 case NID_id_GostR3410_2012_512:
545 return SSL_PKEY_GOST12_512;
550 int ssl_verify_alarm_type(long type)
555 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
556 case X509_V_ERR_UNABLE_TO_GET_CRL:
557 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
558 al = SSL_AD_UNKNOWN_CA;
560 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
561 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
562 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
563 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
564 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
565 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
566 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
567 case X509_V_ERR_CERT_NOT_YET_VALID:
568 case X509_V_ERR_CRL_NOT_YET_VALID:
569 case X509_V_ERR_CERT_UNTRUSTED:
570 case X509_V_ERR_CERT_REJECTED:
571 case X509_V_ERR_HOSTNAME_MISMATCH:
572 case X509_V_ERR_EMAIL_MISMATCH:
573 case X509_V_ERR_IP_ADDRESS_MISMATCH:
574 case X509_V_ERR_DANE_NO_MATCH:
575 case X509_V_ERR_EE_KEY_TOO_SMALL:
576 case X509_V_ERR_CA_KEY_TOO_SMALL:
577 case X509_V_ERR_CA_MD_TOO_WEAK:
578 al = SSL_AD_BAD_CERTIFICATE;
580 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
581 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
582 al = SSL_AD_DECRYPT_ERROR;
584 case X509_V_ERR_CERT_HAS_EXPIRED:
585 case X509_V_ERR_CRL_HAS_EXPIRED:
586 al = SSL_AD_CERTIFICATE_EXPIRED;
588 case X509_V_ERR_CERT_REVOKED:
589 al = SSL_AD_CERTIFICATE_REVOKED;
591 case X509_V_ERR_UNSPECIFIED:
592 case X509_V_ERR_OUT_OF_MEM:
593 case X509_V_ERR_INVALID_CALL:
594 case X509_V_ERR_STORE_LOOKUP:
595 al = SSL_AD_INTERNAL_ERROR;
597 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
598 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
599 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
600 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
601 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
602 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
603 case X509_V_ERR_INVALID_CA:
604 al = SSL_AD_UNKNOWN_CA;
606 case X509_V_ERR_APPLICATION_VERIFICATION:
607 al = SSL_AD_HANDSHAKE_FAILURE;
609 case X509_V_ERR_INVALID_PURPOSE:
610 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
613 al = SSL_AD_CERTIFICATE_UNKNOWN;
619 int ssl_allow_compression(SSL *s)
621 if (s->options & SSL_OP_NO_COMPRESSION)
623 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
626 static int version_cmp(const SSL *s, int a, int b)
628 int dtls = SSL_IS_DTLS(s);
633 return a < b ? -1 : 1;
634 return DTLS_VERSION_LT(a, b) ? -1 : 1;
639 const SSL_METHOD *(*cmeth) (void);
640 const SSL_METHOD *(*smeth) (void);
643 #if TLS_MAX_VERSION != TLS1_2_VERSION
644 # error Code needs update for TLS_method() support beyond TLS1_2_VERSION.
647 static const version_info tls_version_table[] = {
648 #ifndef OPENSSL_NO_TLS1_2
649 {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
651 {TLS1_2_VERSION, NULL, NULL},
653 #ifndef OPENSSL_NO_TLS1_1
654 {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
656 {TLS1_1_VERSION, NULL, NULL},
658 #ifndef OPENSSL_NO_TLS1
659 {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
661 {TLS1_VERSION, NULL, NULL},
663 #ifndef OPENSSL_NO_SSL3
664 {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
666 {SSL3_VERSION, NULL, NULL},
671 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
672 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
675 static const version_info dtls_version_table[] = {
676 #ifndef OPENSSL_NO_DTLS1_2
677 {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
679 {DTLS1_2_VERSION, NULL, NULL},
681 #ifndef OPENSSL_NO_DTLS1
682 {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
683 {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
685 {DTLS1_VERSION, NULL, NULL},
686 {DTLS1_BAD_VER, NULL, NULL},
692 * ssl_method_error - Check whether an SSL_METHOD is enabled.
694 * @s: The SSL handle for the candidate method
695 * @method: the intended method.
697 * Returns 0 on success, or an SSL error reason on failure.
699 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
701 int version = method->version;
703 if ((s->min_proto_version != 0 &&
704 version_cmp(s, version, s->min_proto_version) < 0) ||
705 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
706 return SSL_R_VERSION_TOO_LOW;
708 if (s->max_proto_version != 0 &&
709 version_cmp(s, version, s->max_proto_version) > 0)
710 return SSL_R_VERSION_TOO_HIGH;
712 if ((s->options & method->mask) != 0)
713 return SSL_R_UNSUPPORTED_PROTOCOL;
714 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
715 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
716 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
717 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
723 * ssl_version_supported - Check that the specified `version` is supported by
726 * @s: The SSL handle for the candidate method
727 * @version: Protocol version to test against
729 * Returns 1 when supported, otherwise 0
731 int ssl_version_supported(const SSL *s, int version)
733 const version_info *vent;
734 const version_info *table;
736 switch (s->method->version) {
738 /* Version should match method version for non-ANY method */
739 return version_cmp(s, version, s->version) == 0;
740 case TLS_ANY_VERSION:
741 table = tls_version_table;
743 case DTLS_ANY_VERSION:
744 table = dtls_version_table;
749 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
751 if (vent->cmeth != NULL &&
752 version_cmp(s, version, vent->version) == 0 &&
753 ssl_method_error(s, vent->cmeth()) == 0) {
761 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
762 * fallback indication from a client check whether we're using the highest
763 * supported protocol version.
765 * @s server SSL handle.
767 * Returns 1 when using the highest enabled version, 0 otherwise.
769 int ssl_check_version_downgrade(SSL *s)
771 const version_info *vent;
772 const version_info *table;
775 * Check that the current protocol is the highest enabled version
776 * (according to s->ctx->method, as version negotiation may have changed
779 if (s->version == s->ctx->method->version)
783 * Apparently we're using a version-flexible SSL_METHOD (not at its
784 * highest protocol version).
786 if (s->ctx->method->version == TLS_method()->version)
787 table = tls_version_table;
788 else if (s->ctx->method->version == DTLS_method()->version)
789 table = dtls_version_table;
791 /* Unexpected state; fail closed. */
795 for (vent = table; vent->version != 0; ++vent) {
796 if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
797 return s->version == vent->version;
803 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
804 * protocols, provided the initial (D)TLS method is version-flexible. This
805 * function sanity-checks the proposed value and makes sure the method is
806 * version-flexible, then sets the limit if all is well.
808 * @method_version: The version of the current SSL_METHOD.
809 * @version: the intended limit.
810 * @bound: pointer to limit to be updated.
812 * Returns 1 on success, 0 on failure.
814 int ssl_set_version_bound(int method_version, int version, int *bound)
822 * Restrict TLS methods to TLS protocol versions.
823 * Restrict DTLS methods to DTLS protocol versions.
824 * Note, DTLS version numbers are decreasing, use comparison macros.
826 * Note that for both lower-bounds we use explicit versions, not
827 * (D)TLS_MIN_VERSION. This is because we don't want to break user
828 * configurations. If the MIN (supported) version ever rises, the user's
829 * "floor" remains valid even if no longer available. We don't expect the
830 * MAX ceiling to ever get lower, so making that variable makes sense.
832 switch (method_version) {
835 * XXX For fixed version methods, should we always fail and not set any
836 * bounds, always succeed and not set any bounds, or set the bounds and
837 * arrange to fail later if they are not met? At present fixed-version
838 * methods are not subject to controls that disable individual protocol
843 case TLS_ANY_VERSION:
844 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
848 case DTLS_ANY_VERSION:
849 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
850 DTLS_VERSION_LT(version, DTLS1_BAD_VER))
860 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
861 * client HELLO is received to select the final server protocol version and
862 * the version specific method.
864 * @s: server SSL handle.
866 * Returns 0 on success or an SSL error reason number on failure.
868 int ssl_choose_server_version(SSL *s)
871 * With version-flexible methods we have an initial state with:
873 * s->method->version == (D)TLS_ANY_VERSION,
874 * s->version == (D)TLS_MAX_VERSION.
876 * So we detect version-flexible methods via the method version, not the
879 int server_version = s->method->version;
880 int client_version = s->client_version;
881 const version_info *vent;
882 const version_info *table;
885 switch (server_version) {
887 if (version_cmp(s, client_version, s->version) < 0)
888 return SSL_R_WRONG_SSL_VERSION;
890 * If this SSL handle is not from a version flexible method we don't
891 * (and never did) check min/max FIPS or Suite B constraints. Hope
892 * that's OK. It is up to the caller to not choose fixed protocol
893 * versions they don't want. If not, then easy to fix, just return
894 * ssl_method_error(s, s->method)
897 case TLS_ANY_VERSION:
898 table = tls_version_table;
900 case DTLS_ANY_VERSION:
901 table = dtls_version_table;
905 for (vent = table; vent->version != 0; ++vent) {
906 const SSL_METHOD *method;
908 if (vent->smeth == NULL ||
909 version_cmp(s, client_version, vent->version) < 0)
911 method = vent->smeth();
912 if (ssl_method_error(s, method) == 0) {
913 s->version = vent->version;
919 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
923 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
924 * server HELLO is received to select the final client protocol version and
925 * the version specific method.
927 * @s: client SSL handle.
928 * @version: The proposed version from the server's HELLO.
930 * Returns 0 on success or an SSL error reason number on failure.
932 int ssl_choose_client_version(SSL *s, int version)
934 const version_info *vent;
935 const version_info *table;
937 switch (s->method->version) {
939 if (version != s->version)
940 return SSL_R_WRONG_SSL_VERSION;
942 * If this SSL handle is not from a version flexible method we don't
943 * (and never did) check min/max, FIPS or Suite B constraints. Hope
944 * that's OK. It is up to the caller to not choose fixed protocol
945 * versions they don't want. If not, then easy to fix, just return
946 * ssl_method_error(s, s->method)
949 case TLS_ANY_VERSION:
950 table = tls_version_table;
952 case DTLS_ANY_VERSION:
953 table = dtls_version_table;
957 for (vent = table; vent->version != 0; ++vent) {
958 const SSL_METHOD *method;
961 if (version != vent->version)
963 if (vent->cmeth == NULL)
965 method = vent->cmeth();
966 err = ssl_method_error(s, method);
970 s->version = version;
974 return SSL_R_UNSUPPORTED_PROTOCOL;
978 * ssl_get_client_min_max_version - get minimum and maximum client version
979 * @s: The SSL connection
980 * @min_version: The minimum supported version
981 * @max_version: The maximum supported version
983 * Work out what version we should be using for the initial ClientHello if the
984 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
985 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
986 * or FIPS_mode() constraints and any floor imposed by the security level here,
987 * so we don't advertise the wrong protocol version to only reject the outcome later.
989 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
990 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
991 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
993 * Returns 0 on success or an SSL error reason number on failure. On failure
994 * min_version and max_version will also be set to 0.
996 int ssl_get_client_min_max_version(const SSL *s, int *min_version,
1001 const SSL_METHOD *single = NULL;
1002 const SSL_METHOD *method;
1003 const version_info *table;
1004 const version_info *vent;
1006 switch (s->method->version) {
1009 * If this SSL handle is not from a version flexible method we don't
1010 * (and never did) check min/max FIPS or Suite B constraints. Hope
1011 * that's OK. It is up to the caller to not choose fixed protocol
1012 * versions they don't want. If not, then easy to fix, just return
1013 * ssl_method_error(s, s->method)
1015 *min_version = *max_version = s->version;
1017 case TLS_ANY_VERSION:
1018 table = tls_version_table;
1020 case DTLS_ANY_VERSION:
1021 table = dtls_version_table;
1026 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1027 * below X enabled. This is required in order to maintain the "version
1028 * capability" vector contiguous. Any versions with a NULL client method
1029 * (protocol version client is disabled at compile-time) is also a "hole".
1031 * Our initial state is hole == 1, version == 0. That is, versions above
1032 * the first version in the method table are disabled (a "hole" above
1033 * the valid protocol entries) and we don't have a selected version yet.
1035 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1036 * the selected version, and the method becomes a candidate "single"
1037 * method. We're no longer in a hole, so "hole" becomes 0.
1039 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1040 * as we support a contiguous range of at least two methods. If we hit
1041 * a disabled method, then hole becomes true again, but nothing else
1042 * changes yet, because all the remaining methods may be disabled too.
1043 * If we again hit an enabled method after the new hole, it becomes
1044 * selected, as we start from scratch.
1046 *min_version = version = 0;
1048 for (vent = table; vent->version != 0; ++vent) {
1050 * A table entry with a NULL client method is still a hole in the
1051 * "version capability" vector.
1053 if (vent->cmeth == NULL) {
1057 method = vent->cmeth();
1058 if (ssl_method_error(s, method) != 0) {
1062 *min_version = method->version;
1064 version = (single = method)->version;
1065 *min_version = version;
1070 *max_version = version;
1072 /* Fail if everything is disabled */
1074 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1080 * ssl_set_client_hello_version - Work out what version we should be using for
1081 * the initial ClientHello.
1083 * @s: client SSL handle.
1085 * Returns 0 on success or an SSL error reason number on failure.
1087 int ssl_set_client_hello_version(SSL *s)
1089 int ver_min, ver_max, ret;
1091 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1096 s->client_version = s->version = ver_max;