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)
35 ret = ssl3_write_bytes(s, type, &s->init_buf->data[s->init_off],
36 s->init_num, &written);
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 if (!ssl3_finish_mac(s,
45 (unsigned char *)&s->init_buf->data[s->init_off],
49 if (written == s->init_num) {
51 s->msg_callback(1, s->version, type, s->init_buf->data,
52 (size_t)(s->init_off + s->init_num), s,
56 s->init_off += written;
57 s->init_num -= written;
61 int tls_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
65 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
66 || !WPACKET_get_length(pkt, &msglen)
69 s->init_num = (int)msglen;
75 int tls_construct_cert_verify(SSL *s, WPACKET *pkt)
78 const EVP_MD *md = s->s3->tmp.md[s->cert->key - s->cert->pkeys];
79 EVP_MD_CTX *mctx = NULL;
83 unsigned char *sig = NULL;
85 mctx = EVP_MD_CTX_new();
87 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
90 pkey = s->cert->key->privatekey;
92 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
94 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
98 if (SSL_USE_SIGALGS(s)&& !tls12_get_sigandhash(pkt, pkey, md)) {
99 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
103 fprintf(stderr, "Using client alg %s\n", EVP_MD_name(md));
105 sig = OPENSSL_malloc(EVP_PKEY_size(pkey));
107 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
110 if (!EVP_SignInit_ex(mctx, md, NULL)
111 || !EVP_SignUpdate(mctx, hdata, hdatalen)
112 || (s->version == SSL3_VERSION
113 && !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
114 (int)s->session->master_key_length,
115 s->session->master_key))
116 || !EVP_SignFinal(mctx, sig, &u, pkey)) {
117 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_EVP_LIB);
120 #ifndef OPENSSL_NO_GOST
122 int pktype = EVP_PKEY_id(pkey);
123 if (pktype == NID_id_GostR3410_2001
124 || pktype == NID_id_GostR3410_2012_256
125 || pktype == NID_id_GostR3410_2012_512)
126 BUF_reverse(sig, NULL, u);
130 if (!WPACKET_sub_memcpy_u16(pkt, sig, u)) {
131 SSLerr(SSL_F_TLS_CONSTRUCT_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
135 /* Digest cached records and discard handshake buffer */
136 if (!ssl3_digest_cached_records(s, 0))
140 EVP_MD_CTX_free(mctx);
144 EVP_MD_CTX_free(mctx);
145 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
149 MSG_PROCESS_RETURN tls_process_cert_verify(SSL *s, PACKET *pkt)
151 EVP_PKEY *pkey = NULL;
152 const unsigned char *sig, *data;
153 #ifndef OPENSSL_NO_GOST
154 unsigned char *gost_data = NULL;
156 int al, ret = MSG_PROCESS_ERROR;
160 const EVP_MD *md = NULL;
164 EVP_MD_CTX *mctx = EVP_MD_CTX_new();
167 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
168 al = SSL_AD_INTERNAL_ERROR;
172 peer = s->session->peer;
173 pkey = X509_get0_pubkey(peer);
174 type = X509_certificate_type(peer, pkey);
176 if (!(type & EVP_PKT_SIGN)) {
177 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY,
178 SSL_R_SIGNATURE_FOR_NON_SIGNING_CERTIFICATE);
179 al = SSL_AD_ILLEGAL_PARAMETER;
183 /* Check for broken implementations of GOST ciphersuites */
185 * If key is GOST and n is exactly 64, it is bare signature without
186 * length field (CryptoPro implementations at least till CSP 4.0)
188 #ifndef OPENSSL_NO_GOST
189 if (PACKET_remaining(pkt) == 64
190 && EVP_PKEY_id(pkey) == NID_id_GostR3410_2001) {
195 if (SSL_USE_SIGALGS(s)) {
198 if (!PACKET_get_bytes(pkt, &sig, 2)) {
199 al = SSL_AD_DECODE_ERROR;
202 rv = tls12_check_peer_sigalg(&md, s, sig, pkey);
204 al = SSL_AD_INTERNAL_ERROR;
206 } else if (rv == 0) {
207 al = SSL_AD_DECODE_ERROR;
211 fprintf(stderr, "USING TLSv1.2 HASH %s\n", EVP_MD_name(md));
214 /* Use default digest for this key type */
215 int idx = ssl_cert_type(NULL, pkey);
217 md = s->s3->tmp.md[idx];
219 al = SSL_AD_INTERNAL_ERROR;
224 if (!PACKET_get_net_2(pkt, &len)) {
225 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
226 al = SSL_AD_DECODE_ERROR;
230 j = EVP_PKEY_size(pkey);
231 if (((int)len > j) || ((int)PACKET_remaining(pkt) > j)
232 || (PACKET_remaining(pkt) == 0)) {
233 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_WRONG_SIGNATURE_SIZE);
234 al = SSL_AD_DECODE_ERROR;
237 if (!PACKET_get_bytes(pkt, &data, len)) {
238 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_LENGTH_MISMATCH);
239 al = SSL_AD_DECODE_ERROR;
243 hdatalen = BIO_get_mem_data(s->s3->handshake_buffer, &hdata);
245 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_INTERNAL_ERROR);
246 al = SSL_AD_INTERNAL_ERROR;
251 fprintf(stderr, "Using client verify alg %s\n", EVP_MD_name(md));
253 if (!EVP_VerifyInit_ex(mctx, md, NULL)
254 || !EVP_VerifyUpdate(mctx, hdata, hdatalen)) {
255 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
256 al = SSL_AD_INTERNAL_ERROR;
259 #ifndef OPENSSL_NO_GOST
261 int pktype = EVP_PKEY_id(pkey);
262 if (pktype == NID_id_GostR3410_2001
263 || pktype == NID_id_GostR3410_2012_256
264 || pktype == NID_id_GostR3410_2012_512) {
265 if ((gost_data = OPENSSL_malloc(len)) == NULL) {
266 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_MALLOC_FAILURE);
267 al = SSL_AD_INTERNAL_ERROR;
270 BUF_reverse(gost_data, data, len);
276 if (s->version == SSL3_VERSION
277 && !EVP_MD_CTX_ctrl(mctx, EVP_CTRL_SSL3_MASTER_SECRET,
278 (int)s->session->master_key_length,
279 s->session->master_key)) {
280 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, ERR_R_EVP_LIB);
281 al = SSL_AD_INTERNAL_ERROR;
285 if (EVP_VerifyFinal(mctx, data, len, pkey) <= 0) {
286 al = SSL_AD_DECRYPT_ERROR;
287 SSLerr(SSL_F_TLS_PROCESS_CERT_VERIFY, SSL_R_BAD_SIGNATURE);
291 ret = MSG_PROCESS_CONTINUE_PROCESSING;
294 ssl3_send_alert(s, SSL3_AL_FATAL, al);
295 ossl_statem_set_error(s);
297 BIO_free(s->s3->handshake_buffer);
298 s->s3->handshake_buffer = NULL;
299 EVP_MD_CTX_free(mctx);
300 #ifndef OPENSSL_NO_GOST
301 OPENSSL_free(gost_data);
306 int tls_construct_finished(SSL *s, WPACKET *pkt)
308 size_t finish_md_len;
313 sender = s->method->ssl3_enc->server_finished_label;
314 slen = s->method->ssl3_enc->server_finished_label_len;
316 sender = s->method->ssl3_enc->client_finished_label;
317 slen = s->method->ssl3_enc->client_finished_label_len;
320 finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
322 s->s3->tmp.finish_md);
323 if (finish_md_len == 0) {
324 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
328 s->s3->tmp.finish_md_len = finish_md_len;
330 if (!WPACKET_memcpy(pkt, s->s3->tmp.finish_md, finish_md_len)) {
331 SSLerr(SSL_F_TLS_CONSTRUCT_FINISHED, ERR_R_INTERNAL_ERROR);
336 * Copy the finished so we can use it for renegotiation checks
339 OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
340 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md,
342 s->s3->previous_client_finished_len = finish_md_len;
344 OPENSSL_assert(finish_md_len <= EVP_MAX_MD_SIZE);
345 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md,
347 s->s3->previous_server_finished_len = finish_md_len;
352 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
356 #ifndef OPENSSL_NO_NEXTPROTONEG
358 * ssl3_take_mac calculates the Finished MAC for the handshakes messages seen
361 static void ssl3_take_mac(SSL *s)
366 * If no new cipher setup return immediately: other functions will set
367 * the appropriate error.
369 if (s->s3->tmp.new_cipher == NULL)
372 sender = s->method->ssl3_enc->server_finished_label;
373 slen = s->method->ssl3_enc->server_finished_label_len;
375 sender = s->method->ssl3_enc->client_finished_label;
376 slen = s->method->ssl3_enc->client_finished_label_len;
379 s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
382 s->s3->tmp.peer_finish_md);
386 MSG_PROCESS_RETURN tls_process_change_cipher_spec(SSL *s, PACKET *pkt)
391 remain = PACKET_remaining(pkt);
393 * 'Change Cipher Spec' is just a single byte, which should already have
394 * been consumed by ssl_get_message() so there should be no bytes left,
395 * unless we're using DTLS1_BAD_VER, which has an extra 2 bytes
397 if (SSL_IS_DTLS(s)) {
398 if ((s->version == DTLS1_BAD_VER
399 && remain != DTLS1_CCS_HEADER_LENGTH + 1)
400 || (s->version != DTLS1_BAD_VER
401 && remain != DTLS1_CCS_HEADER_LENGTH - 1)) {
402 al = SSL_AD_ILLEGAL_PARAMETER;
403 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
404 SSL_R_BAD_CHANGE_CIPHER_SPEC);
409 al = SSL_AD_ILLEGAL_PARAMETER;
410 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC,
411 SSL_R_BAD_CHANGE_CIPHER_SPEC);
416 /* Check we have a cipher to change to */
417 if (s->s3->tmp.new_cipher == NULL) {
418 al = SSL_AD_UNEXPECTED_MESSAGE;
419 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, SSL_R_CCS_RECEIVED_EARLY);
423 s->s3->change_cipher_spec = 1;
424 if (!ssl3_do_change_cipher_spec(s)) {
425 al = SSL_AD_INTERNAL_ERROR;
426 SSLerr(SSL_F_TLS_PROCESS_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
430 if (SSL_IS_DTLS(s)) {
431 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
433 if (s->version == DTLS1_BAD_VER)
434 s->d1->handshake_read_seq++;
436 #ifndef OPENSSL_NO_SCTP
438 * Remember that a CCS has been received, so that an old key of
439 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
442 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
446 return MSG_PROCESS_CONTINUE_READING;
448 ssl3_send_alert(s, SSL3_AL_FATAL, al);
449 ossl_statem_set_error(s);
450 return MSG_PROCESS_ERROR;
453 MSG_PROCESS_RETURN tls_process_finished(SSL *s, PACKET *pkt)
455 int al = SSL_AD_INTERNAL_ERROR;
458 /* If this occurs, we have missed a message */
459 if (!SSL_IS_TLS13(s) && !s->s3->change_cipher_spec) {
460 al = SSL_AD_UNEXPECTED_MESSAGE;
461 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_GOT_A_FIN_BEFORE_A_CCS);
464 s->s3->change_cipher_spec = 0;
466 md_len = s->s3->tmp.peer_finish_md_len;
468 if (md_len != PACKET_remaining(pkt)) {
469 al = SSL_AD_DECODE_ERROR;
470 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_BAD_DIGEST_LENGTH);
474 if (CRYPTO_memcmp(PACKET_data(pkt), s->s3->tmp.peer_finish_md,
476 al = SSL_AD_DECRYPT_ERROR;
477 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_DIGEST_CHECK_FAILED);
482 * Copy the finished so we can use it for renegotiation checks
485 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
486 memcpy(s->s3->previous_client_finished, s->s3->tmp.peer_finish_md,
488 s->s3->previous_client_finished_len = md_len;
490 OPENSSL_assert(md_len <= EVP_MAX_MD_SIZE);
491 memcpy(s->s3->previous_server_finished, s->s3->tmp.peer_finish_md,
493 s->s3->previous_server_finished_len = md_len;
497 * In TLS1.3 we also have to change cipher state and do any final processing
498 * of the initial server flight (if we are a client)
500 if (SSL_IS_TLS13(s)) {
502 if (!s->method->ssl3_enc->change_cipher_state(s,
503 SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_SERVER_READ)) {
504 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
508 if (!s->method->ssl3_enc->generate_master_secret(s,
509 s->session->master_key, s->handshake_secret, 0,
510 &s->session->master_key_length)) {
511 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
514 if (!s->method->ssl3_enc->change_cipher_state(s,
515 SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_READ)) {
516 SSLerr(SSL_F_TLS_PROCESS_FINISHED, SSL_R_CANNOT_CHANGE_CIPHER);
519 if (!tls_process_initial_server_flight(s, &al))
524 return MSG_PROCESS_FINISHED_READING;
526 ssl3_send_alert(s, SSL3_AL_FATAL, al);
527 ossl_statem_set_error(s);
528 return MSG_PROCESS_ERROR;
531 int tls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
533 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS)) {
534 SSLerr(SSL_F_TLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
535 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
542 /* Add a certificate to the WPACKET */
543 static int ssl_add_cert_to_wpacket(SSL *s, WPACKET *pkt, X509 *x, int chain,
547 unsigned char *outbytes;
549 len = i2d_X509(x, NULL);
551 SSLerr(SSL_F_SSL_ADD_CERT_TO_WPACKET, ERR_R_BUF_LIB);
552 *al = SSL_AD_INTERNAL_ERROR;
555 if (!WPACKET_sub_allocate_bytes_u24(pkt, len, &outbytes)
556 || i2d_X509(x, &outbytes) != len) {
557 SSLerr(SSL_F_SSL_ADD_CERT_TO_WPACKET, ERR_R_INTERNAL_ERROR);
558 *al = SSL_AD_INTERNAL_ERROR;
563 && !tls_construct_extensions(s, pkt, EXT_TLS1_3_CERTIFICATE, x,
570 /* Add certificate chain to provided WPACKET */
571 static int ssl_add_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk, int *al)
575 STACK_OF(X509) *extra_certs;
576 STACK_OF(X509) *chain = NULL;
577 X509_STORE *chain_store;
578 int tmpal = SSL_AD_INTERNAL_ERROR;
580 if (cpk == NULL || cpk->x509 == NULL)
586 * If we have a certificate specific chain use it, else use parent ctx.
588 if (cpk->chain != NULL)
589 extra_certs = cpk->chain;
591 extra_certs = s->ctx->extra_certs;
593 if ((s->mode & SSL_MODE_NO_AUTO_CHAIN) || extra_certs)
595 else if (s->cert->chain_store)
596 chain_store = s->cert->chain_store;
598 chain_store = s->ctx->cert_store;
600 if (chain_store != NULL) {
601 X509_STORE_CTX *xs_ctx = X509_STORE_CTX_new();
603 if (xs_ctx == NULL) {
604 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, ERR_R_MALLOC_FAILURE);
607 if (!X509_STORE_CTX_init(xs_ctx, chain_store, x, NULL)) {
608 X509_STORE_CTX_free(xs_ctx);
609 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, ERR_R_X509_LIB);
613 * It is valid for the chain not to be complete (because normally we
614 * don't include the root cert in the chain). Therefore we deliberately
615 * ignore the error return from this call. We're not actually verifying
616 * the cert - we're just building as much of the chain as we can
618 (void)X509_verify_cert(xs_ctx);
619 /* Don't leave errors in the queue */
621 chain = X509_STORE_CTX_get0_chain(xs_ctx);
622 i = ssl_security_cert_chain(s, chain, NULL, 0);
625 /* Dummy error calls so mkerr generates them */
626 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_EE_KEY_TOO_SMALL);
627 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_CA_KEY_TOO_SMALL);
628 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, SSL_R_CA_MD_TOO_WEAK);
630 X509_STORE_CTX_free(xs_ctx);
631 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, i);
634 chain_count = sk_X509_num(chain);
635 for (i = 0; i < chain_count; i++) {
636 x = sk_X509_value(chain, i);
638 if (!ssl_add_cert_to_wpacket(s, pkt, x, i, &tmpal)) {
639 X509_STORE_CTX_free(xs_ctx);
643 X509_STORE_CTX_free(xs_ctx);
645 i = ssl_security_cert_chain(s, extra_certs, x, 0);
647 SSLerr(SSL_F_SSL_ADD_CERT_CHAIN, i);
650 if (!ssl_add_cert_to_wpacket(s, pkt, x, 0, &tmpal))
652 for (i = 0; i < sk_X509_num(extra_certs); i++) {
653 x = sk_X509_value(extra_certs, i);
654 if (!ssl_add_cert_to_wpacket(s, pkt, x, i + 1, &tmpal))
665 unsigned long ssl3_output_cert_chain(SSL *s, WPACKET *pkt, CERT_PKEY *cpk,
668 int tmpal = SSL_AD_INTERNAL_ERROR;
670 if (!WPACKET_start_sub_packet_u24(pkt)
671 || !ssl_add_cert_chain(s, pkt, cpk, &tmpal)
672 || !WPACKET_close(pkt)) {
673 SSLerr(SSL_F_SSL3_OUTPUT_CERT_CHAIN, ERR_R_INTERNAL_ERROR);
680 WORK_STATE tls_finish_handshake(SSL *s, WORK_STATE wst)
682 void (*cb) (const SSL *ssl, int type, int val) = NULL;
684 #ifndef OPENSSL_NO_SCTP
685 if (SSL_IS_DTLS(s) && BIO_dgram_is_sctp(SSL_get_wbio(s))) {
687 ret = dtls_wait_for_dry(s);
688 if (ret != WORK_FINISHED_CONTINUE)
693 /* clean a few things up */
694 ssl3_cleanup_key_block(s);
696 if (!SSL_IS_DTLS(s)) {
698 * We don't do this in DTLS because we may still need the init_buf
699 * in case there are any unexpected retransmits
701 BUF_MEM_free(s->init_buf);
705 ssl_free_wbio_buffer(s);
709 if (!s->server || s->renegotiate == 2) {
710 /* skipped if we just sent a HelloRequest */
715 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
717 s->ctx->stats.sess_accept_good++;
718 s->handshake_func = ossl_statem_accept;
720 ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
722 s->ctx->stats.sess_hit++;
724 s->handshake_func = ossl_statem_connect;
725 s->ctx->stats.sess_connect_good++;
728 if (s->info_callback != NULL)
729 cb = s->info_callback;
730 else if (s->ctx->info_callback != NULL)
731 cb = s->ctx->info_callback;
734 cb(s, SSL_CB_HANDSHAKE_DONE, 1);
736 if (SSL_IS_DTLS(s)) {
737 /* done with handshaking */
738 s->d1->handshake_read_seq = 0;
739 s->d1->handshake_write_seq = 0;
740 s->d1->next_handshake_write_seq = 0;
741 dtls1_clear_received_buffer(s);
745 return WORK_FINISHED_STOP;
748 int tls_get_message_header(SSL *s, int *mt)
750 /* s->init_num < SSL3_HM_HEADER_LENGTH */
751 int skip_message, i, recvd_type, al;
755 p = (unsigned char *)s->init_buf->data;
758 while (s->init_num < SSL3_HM_HEADER_LENGTH) {
759 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type,
761 SSL3_HM_HEADER_LENGTH - s->init_num,
764 s->rwstate = SSL_READING;
767 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
769 * A ChangeCipherSpec must be a single byte and may not occur
770 * in the middle of a handshake message.
772 if (s->init_num != 0 || readbytes != 1 || p[0] != SSL3_MT_CCS) {
773 al = SSL_AD_UNEXPECTED_MESSAGE;
774 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER,
775 SSL_R_BAD_CHANGE_CIPHER_SPEC);
778 s->s3->tmp.message_type = *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
779 s->init_num = readbytes - 1;
780 s->init_msg = s->init_buf->data;
781 s->s3->tmp.message_size = readbytes;
783 } else if (recvd_type != SSL3_RT_HANDSHAKE) {
784 al = SSL_AD_UNEXPECTED_MESSAGE;
785 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_CCS_RECEIVED_EARLY);
788 s->init_num += readbytes;
793 if (p[0] == SSL3_MT_HELLO_REQUEST)
795 * The server may always send 'Hello Request' messages --
796 * we are doing a handshake anyway now, so ignore them if
797 * their format is correct. Does not count for 'Finished'
800 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
805 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
806 p, SSL3_HM_HEADER_LENGTH, s,
807 s->msg_callback_arg);
809 } while (skip_message);
810 /* s->init_num == SSL3_HM_HEADER_LENGTH */
813 s->s3->tmp.message_type = *(p++);
815 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
817 * Only happens with SSLv3+ in an SSLv2 backward compatible
820 * Total message size is the remaining record bytes to read
821 * plus the SSL3_HM_HEADER_LENGTH bytes that we already read
823 l = RECORD_LAYER_get_rrec_length(&s->rlayer)
824 + SSL3_HM_HEADER_LENGTH;
825 s->s3->tmp.message_size = l;
827 s->init_msg = s->init_buf->data;
828 s->init_num = SSL3_HM_HEADER_LENGTH;
831 /* BUF_MEM_grow takes an 'int' parameter */
832 if (l > (INT_MAX - SSL3_HM_HEADER_LENGTH)) {
833 al = SSL_AD_ILLEGAL_PARAMETER;
834 SSLerr(SSL_F_TLS_GET_MESSAGE_HEADER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
837 s->s3->tmp.message_size = l;
839 s->init_msg = s->init_buf->data + SSL3_HM_HEADER_LENGTH;
845 ssl3_send_alert(s, SSL3_AL_FATAL, al);
849 int tls_get_message_body(SSL *s, size_t *len)
855 if (s->s3->tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
856 /* We've already read everything in */
857 *len = (unsigned long)s->init_num;
862 n = s->s3->tmp.message_size - s->init_num;
864 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
865 &p[s->init_num], n, 0, &readbytes);
867 s->rwstate = SSL_READING;
871 s->init_num += readbytes;
875 #ifndef OPENSSL_NO_NEXTPROTONEG
877 * If receiving Finished, record MAC of prior handshake messages for
878 * Finished verification.
880 if (*s->init_buf->data == SSL3_MT_FINISHED)
884 /* Feed this message into MAC computation. */
885 if (RECORD_LAYER_is_sslv2_record(&s->rlayer)) {
886 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
888 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
889 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
894 s->msg_callback(0, SSL2_VERSION, 0, s->init_buf->data,
895 (size_t)s->init_num, s, s->msg_callback_arg);
897 if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
898 s->init_num + SSL3_HM_HEADER_LENGTH)) {
899 SSLerr(SSL_F_TLS_GET_MESSAGE_BODY, ERR_R_EVP_LIB);
900 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
905 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
906 (size_t)s->init_num + SSL3_HM_HEADER_LENGTH, s,
907 s->msg_callback_arg);
914 int ssl_cert_type(const X509 *x, const EVP_PKEY *pk)
916 if (pk == NULL && (pk = X509_get0_pubkey(x)) == NULL)
919 switch (EVP_PKEY_id(pk)) {
923 return SSL_PKEY_RSA_ENC;
925 return SSL_PKEY_DSA_SIGN;
926 #ifndef OPENSSL_NO_EC
930 #ifndef OPENSSL_NO_GOST
931 case NID_id_GostR3410_2001:
932 return SSL_PKEY_GOST01;
933 case NID_id_GostR3410_2012_256:
934 return SSL_PKEY_GOST12_256;
935 case NID_id_GostR3410_2012_512:
936 return SSL_PKEY_GOST12_512;
941 int ssl_verify_alarm_type(long type)
946 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
947 case X509_V_ERR_UNABLE_TO_GET_CRL:
948 case X509_V_ERR_UNABLE_TO_GET_CRL_ISSUER:
949 al = SSL_AD_UNKNOWN_CA;
951 case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
952 case X509_V_ERR_UNABLE_TO_DECRYPT_CRL_SIGNATURE:
953 case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
954 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
955 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
956 case X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD:
957 case X509_V_ERR_ERROR_IN_CRL_NEXT_UPDATE_FIELD:
958 case X509_V_ERR_CERT_NOT_YET_VALID:
959 case X509_V_ERR_CRL_NOT_YET_VALID:
960 case X509_V_ERR_CERT_UNTRUSTED:
961 case X509_V_ERR_CERT_REJECTED:
962 case X509_V_ERR_HOSTNAME_MISMATCH:
963 case X509_V_ERR_EMAIL_MISMATCH:
964 case X509_V_ERR_IP_ADDRESS_MISMATCH:
965 case X509_V_ERR_DANE_NO_MATCH:
966 case X509_V_ERR_EE_KEY_TOO_SMALL:
967 case X509_V_ERR_CA_KEY_TOO_SMALL:
968 case X509_V_ERR_CA_MD_TOO_WEAK:
969 al = SSL_AD_BAD_CERTIFICATE;
971 case X509_V_ERR_CERT_SIGNATURE_FAILURE:
972 case X509_V_ERR_CRL_SIGNATURE_FAILURE:
973 al = SSL_AD_DECRYPT_ERROR;
975 case X509_V_ERR_CERT_HAS_EXPIRED:
976 case X509_V_ERR_CRL_HAS_EXPIRED:
977 al = SSL_AD_CERTIFICATE_EXPIRED;
979 case X509_V_ERR_CERT_REVOKED:
980 al = SSL_AD_CERTIFICATE_REVOKED;
982 case X509_V_ERR_UNSPECIFIED:
983 case X509_V_ERR_OUT_OF_MEM:
984 case X509_V_ERR_INVALID_CALL:
985 case X509_V_ERR_STORE_LOOKUP:
986 al = SSL_AD_INTERNAL_ERROR;
988 case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
989 case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
990 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
991 case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
992 case X509_V_ERR_CERT_CHAIN_TOO_LONG:
993 case X509_V_ERR_PATH_LENGTH_EXCEEDED:
994 case X509_V_ERR_INVALID_CA:
995 al = SSL_AD_UNKNOWN_CA;
997 case X509_V_ERR_APPLICATION_VERIFICATION:
998 al = SSL_AD_HANDSHAKE_FAILURE;
1000 case X509_V_ERR_INVALID_PURPOSE:
1001 al = SSL_AD_UNSUPPORTED_CERTIFICATE;
1004 al = SSL_AD_CERTIFICATE_UNKNOWN;
1010 int ssl_allow_compression(SSL *s)
1012 if (s->options & SSL_OP_NO_COMPRESSION)
1014 return ssl_security(s, SSL_SECOP_COMPRESSION, 0, 0, NULL);
1017 static int version_cmp(const SSL *s, int a, int b)
1019 int dtls = SSL_IS_DTLS(s);
1024 return a < b ? -1 : 1;
1025 return DTLS_VERSION_LT(a, b) ? -1 : 1;
1030 const SSL_METHOD *(*cmeth) (void);
1031 const SSL_METHOD *(*smeth) (void);
1034 #if TLS_MAX_VERSION != TLS1_3_VERSION
1035 # error Code needs update for TLS_method() support beyond TLS1_3_VERSION.
1038 static const version_info tls_version_table[] = {
1039 #ifndef OPENSSL_NO_TLS1_3
1040 {TLS1_3_VERSION, tlsv1_3_client_method, tlsv1_3_server_method},
1042 {TLS1_3_VERSION, NULL, NULL},
1044 #ifndef OPENSSL_NO_TLS1_2
1045 {TLS1_2_VERSION, tlsv1_2_client_method, tlsv1_2_server_method},
1047 {TLS1_2_VERSION, NULL, NULL},
1049 #ifndef OPENSSL_NO_TLS1_1
1050 {TLS1_1_VERSION, tlsv1_1_client_method, tlsv1_1_server_method},
1052 {TLS1_1_VERSION, NULL, NULL},
1054 #ifndef OPENSSL_NO_TLS1
1055 {TLS1_VERSION, tlsv1_client_method, tlsv1_server_method},
1057 {TLS1_VERSION, NULL, NULL},
1059 #ifndef OPENSSL_NO_SSL3
1060 {SSL3_VERSION, sslv3_client_method, sslv3_server_method},
1062 {SSL3_VERSION, NULL, NULL},
1067 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
1068 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
1071 static const version_info dtls_version_table[] = {
1072 #ifndef OPENSSL_NO_DTLS1_2
1073 {DTLS1_2_VERSION, dtlsv1_2_client_method, dtlsv1_2_server_method},
1075 {DTLS1_2_VERSION, NULL, NULL},
1077 #ifndef OPENSSL_NO_DTLS1
1078 {DTLS1_VERSION, dtlsv1_client_method, dtlsv1_server_method},
1079 {DTLS1_BAD_VER, dtls_bad_ver_client_method, NULL},
1081 {DTLS1_VERSION, NULL, NULL},
1082 {DTLS1_BAD_VER, NULL, NULL},
1088 * ssl_method_error - Check whether an SSL_METHOD is enabled.
1090 * @s: The SSL handle for the candidate method
1091 * @method: the intended method.
1093 * Returns 0 on success, or an SSL error reason on failure.
1095 static int ssl_method_error(const SSL *s, const SSL_METHOD *method)
1097 int version = method->version;
1099 if ((s->min_proto_version != 0 &&
1100 version_cmp(s, version, s->min_proto_version) < 0) ||
1101 ssl_security(s, SSL_SECOP_VERSION, 0, version, NULL) == 0)
1102 return SSL_R_VERSION_TOO_LOW;
1104 if (s->max_proto_version != 0 &&
1105 version_cmp(s, version, s->max_proto_version) > 0)
1106 return SSL_R_VERSION_TOO_HIGH;
1108 if ((s->options & method->mask) != 0)
1109 return SSL_R_UNSUPPORTED_PROTOCOL;
1110 if ((method->flags & SSL_METHOD_NO_SUITEB) != 0 && tls1_suiteb(s))
1111 return SSL_R_AT_LEAST_TLS_1_2_NEEDED_IN_SUITEB_MODE;
1112 else if ((method->flags & SSL_METHOD_NO_FIPS) != 0 && FIPS_mode())
1113 return SSL_R_AT_LEAST_TLS_1_0_NEEDED_IN_FIPS_MODE;
1119 * ssl_version_supported - Check that the specified `version` is supported by
1122 * @s: The SSL handle for the candidate method
1123 * @version: Protocol version to test against
1125 * Returns 1 when supported, otherwise 0
1127 int ssl_version_supported(const SSL *s, int version)
1129 const version_info *vent;
1130 const version_info *table;
1132 switch (s->method->version) {
1134 /* Version should match method version for non-ANY method */
1135 return version_cmp(s, version, s->version) == 0;
1136 case TLS_ANY_VERSION:
1137 table = tls_version_table;
1139 case DTLS_ANY_VERSION:
1140 table = dtls_version_table;
1145 vent->version != 0 && version_cmp(s, version, vent->version) <= 0;
1147 if (vent->cmeth != NULL &&
1148 version_cmp(s, version, vent->version) == 0 &&
1149 ssl_method_error(s, vent->cmeth()) == 0) {
1157 * ssl_check_version_downgrade - In response to RFC7507 SCSV version
1158 * fallback indication from a client check whether we're using the highest
1159 * supported protocol version.
1161 * @s server SSL handle.
1163 * Returns 1 when using the highest enabled version, 0 otherwise.
1165 int ssl_check_version_downgrade(SSL *s)
1167 const version_info *vent;
1168 const version_info *table;
1171 * Check that the current protocol is the highest enabled version
1172 * (according to s->ctx->method, as version negotiation may have changed
1175 if (s->version == s->ctx->method->version)
1179 * Apparently we're using a version-flexible SSL_METHOD (not at its
1180 * highest protocol version).
1182 if (s->ctx->method->version == TLS_method()->version)
1183 table = tls_version_table;
1184 else if (s->ctx->method->version == DTLS_method()->version)
1185 table = dtls_version_table;
1187 /* Unexpected state; fail closed. */
1191 for (vent = table; vent->version != 0; ++vent) {
1192 if (vent->smeth != NULL && ssl_method_error(s, vent->smeth()) == 0)
1193 return s->version == vent->version;
1199 * ssl_set_version_bound - set an upper or lower bound on the supported (D)TLS
1200 * protocols, provided the initial (D)TLS method is version-flexible. This
1201 * function sanity-checks the proposed value and makes sure the method is
1202 * version-flexible, then sets the limit if all is well.
1204 * @method_version: The version of the current SSL_METHOD.
1205 * @version: the intended limit.
1206 * @bound: pointer to limit to be updated.
1208 * Returns 1 on success, 0 on failure.
1210 int ssl_set_version_bound(int method_version, int version, int *bound)
1218 * Restrict TLS methods to TLS protocol versions.
1219 * Restrict DTLS methods to DTLS protocol versions.
1220 * Note, DTLS version numbers are decreasing, use comparison macros.
1222 * Note that for both lower-bounds we use explicit versions, not
1223 * (D)TLS_MIN_VERSION. This is because we don't want to break user
1224 * configurations. If the MIN (supported) version ever rises, the user's
1225 * "floor" remains valid even if no longer available. We don't expect the
1226 * MAX ceiling to ever get lower, so making that variable makes sense.
1228 switch (method_version) {
1231 * XXX For fixed version methods, should we always fail and not set any
1232 * bounds, always succeed and not set any bounds, or set the bounds and
1233 * arrange to fail later if they are not met? At present fixed-version
1234 * methods are not subject to controls that disable individual protocol
1239 case TLS_ANY_VERSION:
1240 if (version < SSL3_VERSION || version > TLS_MAX_VERSION)
1244 case DTLS_ANY_VERSION:
1245 if (DTLS_VERSION_GT(version, DTLS_MAX_VERSION) ||
1246 DTLS_VERSION_LT(version, DTLS1_BAD_VER))
1256 * ssl_choose_server_version - Choose server (D)TLS version. Called when the
1257 * client HELLO is received to select the final server protocol version and
1258 * the version specific method.
1260 * @s: server SSL handle.
1262 * Returns 0 on success or an SSL error reason number on failure.
1264 int ssl_choose_server_version(SSL *s, CLIENTHELLO_MSG *hello)
1267 * With version-flexible methods we have an initial state with:
1269 * s->method->version == (D)TLS_ANY_VERSION,
1270 * s->version == (D)TLS_MAX_VERSION.
1272 * So we detect version-flexible methods via the method version, not the
1275 int server_version = s->method->version;
1276 int client_version = hello->legacy_version;
1277 const version_info *vent;
1278 const version_info *table;
1280 RAW_EXTENSION *suppversions;
1282 s->client_version = client_version;
1284 switch (server_version) {
1287 * TODO(TLS1.3): This check will fail if someone attempts to do
1288 * renegotiation in TLS1.3 at the moment. We need to ensure we disable
1289 * renegotiation for TLS1.3
1291 if (version_cmp(s, client_version, s->version) < 0)
1292 return SSL_R_WRONG_SSL_VERSION;
1294 * If this SSL handle is not from a version flexible method we don't
1295 * (and never did) check min/max FIPS or Suite B constraints. Hope
1296 * that's OK. It is up to the caller to not choose fixed protocol
1297 * versions they don't want. If not, then easy to fix, just return
1298 * ssl_method_error(s, s->method)
1301 case TLS_ANY_VERSION:
1302 table = tls_version_table;
1304 case DTLS_ANY_VERSION:
1305 table = dtls_version_table;
1309 suppversions = &hello->pre_proc_exts[TLSEXT_IDX_supported_versions];
1311 if (suppversions->present && !SSL_IS_DTLS(s)) {
1312 unsigned int candidate_vers = 0;
1313 unsigned int best_vers = 0;
1314 const SSL_METHOD *best_method = NULL;
1315 PACKET versionslist;
1317 suppversions->parsed = 1;
1319 if (!PACKET_as_length_prefixed_1(&suppversions->data, &versionslist)) {
1320 /* Trailing or invalid data? */
1321 return SSL_R_LENGTH_MISMATCH;
1324 while (PACKET_get_net_2(&versionslist, &candidate_vers)) {
1325 /* TODO(TLS1.3): Remove this before release */
1326 if (candidate_vers == TLS1_3_VERSION_DRAFT)
1327 candidate_vers = TLS1_3_VERSION;
1329 * TODO(TLS1.3): There is some discussion on the TLS list about
1330 * wheter to ignore versions <TLS1.2 in supported_versions. At the
1331 * moment we honour them if present. To be reviewed later
1333 if (version_cmp(s, candidate_vers, best_vers) <= 0)
1336 vent->version != 0 && vent->version != (int)candidate_vers;
1339 if (vent->version != 0 && vent->smeth != NULL) {
1340 const SSL_METHOD *method;
1342 method = vent->smeth();
1343 if (ssl_method_error(s, method) == 0) {
1344 best_vers = candidate_vers;
1345 best_method = method;
1349 if (PACKET_remaining(&versionslist) != 0) {
1350 /* Trailing data? */
1351 return SSL_R_LENGTH_MISMATCH;
1354 if (best_vers > 0) {
1355 s->version = best_vers;
1356 s->method = best_method;
1359 return SSL_R_UNSUPPORTED_PROTOCOL;
1363 * If the supported versions extension isn't present, then the highest
1364 * version we can negotiate is TLSv1.2
1366 if (version_cmp(s, client_version, TLS1_3_VERSION) >= 0)
1367 client_version = TLS1_2_VERSION;
1370 * No supported versions extension, so we just use the version supplied in
1373 for (vent = table; vent->version != 0; ++vent) {
1374 const SSL_METHOD *method;
1376 if (vent->smeth == NULL ||
1377 version_cmp(s, client_version, vent->version) < 0)
1379 method = vent->smeth();
1380 if (ssl_method_error(s, method) == 0) {
1381 s->version = vent->version;
1387 return disabled ? SSL_R_UNSUPPORTED_PROTOCOL : SSL_R_VERSION_TOO_LOW;
1391 * ssl_choose_client_version - Choose client (D)TLS version. Called when the
1392 * server HELLO is received to select the final client protocol version and
1393 * the version specific method.
1395 * @s: client SSL handle.
1396 * @version: The proposed version from the server's HELLO.
1398 * Returns 0 on success or an SSL error reason number on failure.
1400 int ssl_choose_client_version(SSL *s, int version)
1402 const version_info *vent;
1403 const version_info *table;
1405 /* TODO(TLS1.3): Remove this before release */
1406 if (version == TLS1_3_VERSION_DRAFT)
1407 version = TLS1_3_VERSION;
1409 switch (s->method->version) {
1411 if (version != s->version)
1412 return SSL_R_WRONG_SSL_VERSION;
1414 * If this SSL handle is not from a version flexible method we don't
1415 * (and never did) check min/max, FIPS or Suite B constraints. Hope
1416 * that's OK. It is up to the caller to not choose fixed protocol
1417 * versions they don't want. If not, then easy to fix, just return
1418 * ssl_method_error(s, s->method)
1421 case TLS_ANY_VERSION:
1422 table = tls_version_table;
1424 case DTLS_ANY_VERSION:
1425 table = dtls_version_table;
1429 for (vent = table; vent->version != 0; ++vent) {
1430 const SSL_METHOD *method;
1433 if (version != vent->version)
1435 if (vent->cmeth == NULL)
1437 method = vent->cmeth();
1438 err = ssl_method_error(s, method);
1442 s->version = version;
1446 return SSL_R_UNSUPPORTED_PROTOCOL;
1450 * ssl_get_client_min_max_version - get minimum and maximum client version
1451 * @s: The SSL connection
1452 * @min_version: The minimum supported version
1453 * @max_version: The maximum supported version
1455 * Work out what version we should be using for the initial ClientHello if the
1456 * version is initially (D)TLS_ANY_VERSION. We apply any explicit SSL_OP_NO_xxx
1457 * options, the MinProtocol and MaxProtocol configuration commands, any Suite B
1458 * or FIPS_mode() constraints and any floor imposed by the security level here,
1459 * so we don't advertise the wrong protocol version to only reject the outcome later.
1461 * Computing the right floor matters. If, e.g., TLS 1.0 and 1.2 are enabled,
1462 * TLS 1.1 is disabled, but the security level, Suite-B and/or MinProtocol
1463 * only allow TLS 1.2, we want to advertise TLS1.2, *not* TLS1.
1465 * Returns 0 on success or an SSL error reason number on failure. On failure
1466 * min_version and max_version will also be set to 0.
1468 int ssl_get_client_min_max_version(const SSL *s, int *min_version,
1473 const SSL_METHOD *single = NULL;
1474 const SSL_METHOD *method;
1475 const version_info *table;
1476 const version_info *vent;
1478 switch (s->method->version) {
1481 * If this SSL handle is not from a version flexible method we don't
1482 * (and never did) check min/max FIPS or Suite B constraints. Hope
1483 * that's OK. It is up to the caller to not choose fixed protocol
1484 * versions they don't want. If not, then easy to fix, just return
1485 * ssl_method_error(s, s->method)
1487 *min_version = *max_version = s->version;
1489 case TLS_ANY_VERSION:
1490 table = tls_version_table;
1492 case DTLS_ANY_VERSION:
1493 table = dtls_version_table;
1498 * SSL_OP_NO_X disables all protocols above X *if* there are some protocols
1499 * below X enabled. This is required in order to maintain the "version
1500 * capability" vector contiguous. Any versions with a NULL client method
1501 * (protocol version client is disabled at compile-time) is also a "hole".
1503 * Our initial state is hole == 1, version == 0. That is, versions above
1504 * the first version in the method table are disabled (a "hole" above
1505 * the valid protocol entries) and we don't have a selected version yet.
1507 * Whenever "hole == 1", and we hit an enabled method, its version becomes
1508 * the selected version, and the method becomes a candidate "single"
1509 * method. We're no longer in a hole, so "hole" becomes 0.
1511 * If "hole == 0" and we hit an enabled method, then "single" is cleared,
1512 * as we support a contiguous range of at least two methods. If we hit
1513 * a disabled method, then hole becomes true again, but nothing else
1514 * changes yet, because all the remaining methods may be disabled too.
1515 * If we again hit an enabled method after the new hole, it becomes
1516 * selected, as we start from scratch.
1518 *min_version = version = 0;
1520 for (vent = table; vent->version != 0; ++vent) {
1522 * A table entry with a NULL client method is still a hole in the
1523 * "version capability" vector.
1525 if (vent->cmeth == NULL) {
1529 method = vent->cmeth();
1530 if (ssl_method_error(s, method) != 0) {
1534 *min_version = method->version;
1536 version = (single = method)->version;
1537 *min_version = version;
1542 *max_version = version;
1544 /* Fail if everything is disabled */
1546 return SSL_R_NO_PROTOCOLS_AVAILABLE;
1552 * ssl_set_client_hello_version - Work out what version we should be using for
1553 * the initial ClientHello.legacy_version field.
1555 * @s: client SSL handle.
1557 * Returns 0 on success or an SSL error reason number on failure.
1559 int ssl_set_client_hello_version(SSL *s)
1561 int ver_min, ver_max, ret;
1563 ret = ssl_get_client_min_max_version(s, &ver_min, &ver_max);
1568 s->version = ver_max;
1570 /* TLS1.3 always uses TLS1.2 in the legacy_version field */
1571 if (!SSL_IS_DTLS(s) && ver_max > TLS1_2_VERSION)
1572 ver_max = TLS1_2_VERSION;
1574 s->client_version = ver_max;