mirror of
https://github.com/openssl/openssl.git
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125719ba11
Reviewed-by: Matt Caswell <matt@openssl.org> Reviewed-by: Tomas Mraz <tomas@openssl.org> (Merged from https://github.com/openssl/openssl/pull/24036)
982 lines
30 KiB
C
982 lines
30 KiB
C
/*
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* Copyright 2005-2023 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include "internal/e_os.h"
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#include <stdio.h>
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#include <openssl/objects.h>
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#include <openssl/rand.h>
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#include "ssl_local.h"
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#include "internal/time.h"
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static int dtls1_handshake_write(SSL_CONNECTION *s);
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static size_t dtls1_link_min_mtu(void);
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/* XDTLS: figure out the right values */
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static const size_t g_probable_mtu[] = { 1500, 512, 256 };
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const SSL3_ENC_METHOD DTLSv1_enc_data = {
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tls1_setup_key_block,
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tls1_generate_master_secret,
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tls1_change_cipher_state,
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tls1_final_finish_mac,
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TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
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TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
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tls1_alert_code,
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tls1_export_keying_material,
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SSL_ENC_FLAG_DTLS,
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dtls1_set_handshake_header,
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dtls1_close_construct_packet,
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dtls1_handshake_write
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};
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const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
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tls1_setup_key_block,
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tls1_generate_master_secret,
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tls1_change_cipher_state,
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tls1_final_finish_mac,
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TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
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TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
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tls1_alert_code,
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tls1_export_keying_material,
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SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_SIGALGS
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| SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
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dtls1_set_handshake_header,
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dtls1_close_construct_packet,
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dtls1_handshake_write
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};
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OSSL_TIME dtls1_default_timeout(void)
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{
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/*
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* 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
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* http, the cache would over fill
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*/
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return ossl_seconds2time(60 * 60 * 2);
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}
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int dtls1_new(SSL *ssl)
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{
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DTLS1_STATE *d1;
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SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
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if (s == NULL)
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return 0;
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if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
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return 0;
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}
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if (!ssl3_new(ssl))
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return 0;
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if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
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ssl3_free(ssl);
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return 0;
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}
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d1->buffered_messages = pqueue_new();
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d1->sent_messages = pqueue_new();
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if (s->server) {
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d1->cookie_len = sizeof(s->d1->cookie);
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}
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d1->link_mtu = 0;
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d1->mtu = 0;
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if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
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pqueue_free(d1->buffered_messages);
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pqueue_free(d1->sent_messages);
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OPENSSL_free(d1);
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ssl3_free(ssl);
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return 0;
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}
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s->d1 = d1;
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if (!ssl->method->ssl_clear(ssl))
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return 0;
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return 1;
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}
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static void dtls1_clear_queues(SSL_CONNECTION *s)
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{
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dtls1_clear_received_buffer(s);
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dtls1_clear_sent_buffer(s);
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}
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void dtls1_clear_received_buffer(SSL_CONNECTION *s)
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{
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pitem *item = NULL;
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hm_fragment *frag = NULL;
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while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
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frag = (hm_fragment *)item->data;
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dtls1_hm_fragment_free(frag);
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pitem_free(item);
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}
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}
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void dtls1_clear_sent_buffer(SSL_CONNECTION *s)
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{
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pitem *item = NULL;
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hm_fragment *frag = NULL;
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while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
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frag = (hm_fragment *)item->data;
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if (frag->msg_header.is_ccs
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&& frag->msg_header.saved_retransmit_state.wrlmethod != NULL
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&& s->rlayer.wrl != frag->msg_header.saved_retransmit_state.wrl) {
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/*
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* If we're freeing the CCS then we're done with the old wrl and it
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* can bee freed
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*/
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frag->msg_header.saved_retransmit_state.wrlmethod->free(frag->msg_header.saved_retransmit_state.wrl);
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}
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dtls1_hm_fragment_free(frag);
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pitem_free(item);
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}
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}
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void dtls1_free(SSL *ssl)
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{
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SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
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if (s == NULL)
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return;
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if (s->d1 != NULL) {
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dtls1_clear_queues(s);
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pqueue_free(s->d1->buffered_messages);
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pqueue_free(s->d1->sent_messages);
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}
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DTLS_RECORD_LAYER_free(&s->rlayer);
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ssl3_free(ssl);
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OPENSSL_free(s->d1);
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s->d1 = NULL;
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}
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int dtls1_clear(SSL *ssl)
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{
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pqueue *buffered_messages;
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pqueue *sent_messages;
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size_t mtu;
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size_t link_mtu;
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SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
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if (s == NULL)
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return 0;
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DTLS_RECORD_LAYER_clear(&s->rlayer);
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if (s->d1) {
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DTLS_timer_cb timer_cb = s->d1->timer_cb;
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buffered_messages = s->d1->buffered_messages;
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sent_messages = s->d1->sent_messages;
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mtu = s->d1->mtu;
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link_mtu = s->d1->link_mtu;
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dtls1_clear_queues(s);
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memset(s->d1, 0, sizeof(*s->d1));
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/* Restore the timer callback from previous state */
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s->d1->timer_cb = timer_cb;
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if (s->server) {
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s->d1->cookie_len = sizeof(s->d1->cookie);
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}
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if (SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU) {
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s->d1->mtu = mtu;
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s->d1->link_mtu = link_mtu;
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}
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s->d1->buffered_messages = buffered_messages;
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s->d1->sent_messages = sent_messages;
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}
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if (!ssl3_clear(ssl))
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return 0;
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if (ssl->method->version == DTLS_ANY_VERSION)
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s->version = DTLS_MAX_VERSION_INTERNAL;
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#ifndef OPENSSL_NO_DTLS1_METHOD
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else if (s->options & SSL_OP_CISCO_ANYCONNECT)
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s->client_version = s->version = DTLS1_BAD_VER;
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#endif
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else
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s->version = ssl->method->version;
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return 1;
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}
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long dtls1_ctrl(SSL *ssl, int cmd, long larg, void *parg)
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{
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int ret = 0;
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OSSL_TIME t;
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SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
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if (s == NULL)
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return 0;
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switch (cmd) {
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case DTLS_CTRL_GET_TIMEOUT:
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if (dtls1_get_timeout(s, &t)) {
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*(struct timeval *)parg = ossl_time_to_timeval(t);
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ret = 1;
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}
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break;
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case DTLS_CTRL_HANDLE_TIMEOUT:
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ret = dtls1_handle_timeout(s);
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break;
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case DTLS_CTRL_SET_LINK_MTU:
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if (larg < (long)dtls1_link_min_mtu())
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return 0;
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s->d1->link_mtu = larg;
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return 1;
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case DTLS_CTRL_GET_LINK_MIN_MTU:
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return (long)dtls1_link_min_mtu();
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case SSL_CTRL_SET_MTU:
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/*
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* We may not have a BIO set yet so can't call dtls1_min_mtu()
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* We'll have to make do with dtls1_link_min_mtu() and max overhead
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*/
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if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
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return 0;
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s->d1->mtu = larg;
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return larg;
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default:
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ret = ssl3_ctrl(ssl, cmd, larg, parg);
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break;
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}
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return ret;
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}
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static void dtls1_bio_set_next_timeout(BIO *bio, const DTLS1_STATE *d1)
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{
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struct timeval tv = ossl_time_to_timeval(d1->next_timeout);
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BIO_ctrl(bio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &tv);
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}
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void dtls1_start_timer(SSL_CONNECTION *s)
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{
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OSSL_TIME duration;
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SSL *ssl = SSL_CONNECTION_GET_SSL(s);
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#ifndef OPENSSL_NO_SCTP
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/* Disable timer for SCTP */
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if (BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
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s->d1->next_timeout = ossl_time_zero();
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return;
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}
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#endif
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/*
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* If timer is not set, initialize duration with 1 second or
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* a user-specified value if the timer callback is installed.
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*/
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if (ossl_time_is_zero(s->d1->next_timeout)) {
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if (s->d1->timer_cb != NULL)
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s->d1->timeout_duration_us = s->d1->timer_cb(ssl, 0);
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else
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s->d1->timeout_duration_us = 1000000;
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}
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/* Set timeout to current time plus duration */
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duration = ossl_us2time(s->d1->timeout_duration_us);
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s->d1->next_timeout = ossl_time_add(ossl_time_now(), duration);
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/* set s->d1->next_timeout into ssl->rbio interface */
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dtls1_bio_set_next_timeout(SSL_get_rbio(ssl), s->d1);
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}
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int dtls1_get_timeout(const SSL_CONNECTION *s, OSSL_TIME *timeleft)
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{
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OSSL_TIME timenow;
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/* If no timeout is set, just return NULL */
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if (ossl_time_is_zero(s->d1->next_timeout))
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return 0;
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/* Get current time */
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timenow = ossl_time_now();
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/*
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* If timer already expired or if remaining time is less than 15 ms,
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* set it to 0 to prevent issues because of small divergences with
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* socket timeouts.
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*/
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*timeleft = ossl_time_subtract(s->d1->next_timeout, timenow);
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if (ossl_time_compare(*timeleft, ossl_ms2time(15)) <= 0)
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*timeleft = ossl_time_zero();
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return 1;
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}
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int dtls1_is_timer_expired(SSL_CONNECTION *s)
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{
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OSSL_TIME timeleft;
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/* Get time left until timeout, return false if no timer running */
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if (!dtls1_get_timeout(s, &timeleft))
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return 0;
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/* Return false if timer is not expired yet */
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if (!ossl_time_is_zero(timeleft))
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return 0;
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/* Timer expired, so return true */
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return 1;
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}
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static void dtls1_double_timeout(SSL_CONNECTION *s)
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{
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s->d1->timeout_duration_us *= 2;
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if (s->d1->timeout_duration_us > 60000000)
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s->d1->timeout_duration_us = 60000000;
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}
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void dtls1_stop_timer(SSL_CONNECTION *s)
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{
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/* Reset everything */
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s->d1->timeout_num_alerts = 0;
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s->d1->next_timeout = ossl_time_zero();
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s->d1->timeout_duration_us = 1000000;
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dtls1_bio_set_next_timeout(s->rbio, s->d1);
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/* Clear retransmission buffer */
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dtls1_clear_sent_buffer(s);
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}
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int dtls1_check_timeout_num(SSL_CONNECTION *s)
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{
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size_t mtu;
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SSL *ssl = SSL_CONNECTION_GET_SSL(s);
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s->d1->timeout_num_alerts++;
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/* Reduce MTU after 2 unsuccessful retransmissions */
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if (s->d1->timeout_num_alerts > 2
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&& !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
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mtu =
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BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
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if (mtu < s->d1->mtu)
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s->d1->mtu = mtu;
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}
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if (s->d1->timeout_num_alerts > DTLS1_TMO_ALERT_COUNT) {
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/* fail the connection, enough alerts have been sent */
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SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_READ_TIMEOUT_EXPIRED);
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return -1;
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}
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return 0;
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}
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int dtls1_handle_timeout(SSL_CONNECTION *s)
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{
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/* if no timer is expired, don't do anything */
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if (!dtls1_is_timer_expired(s)) {
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return 0;
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}
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if (s->d1->timer_cb != NULL)
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s->d1->timeout_duration_us = s->d1->timer_cb(SSL_CONNECTION_GET_SSL(s),
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s->d1->timeout_duration_us);
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else
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dtls1_double_timeout(s);
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if (dtls1_check_timeout_num(s) < 0) {
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/* SSLfatal() already called */
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return -1;
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}
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dtls1_start_timer(s);
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/* Calls SSLfatal() if required */
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return dtls1_retransmit_buffered_messages(s);
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}
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#define LISTEN_SUCCESS 2
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#define LISTEN_SEND_VERIFY_REQUEST 1
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#ifndef OPENSSL_NO_SOCK
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int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
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{
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int next, n, ret = 0;
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unsigned char cookie[DTLS1_COOKIE_LENGTH];
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unsigned char seq[SEQ_NUM_SIZE];
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const unsigned char *data;
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unsigned char *buf = NULL, *wbuf;
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size_t fragoff, fraglen, msglen;
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unsigned int rectype, versmajor, versminor, msgseq, msgtype, clientvers, cookielen;
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BIO *rbio, *wbio;
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BIO_ADDR *tmpclient = NULL;
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PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
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SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
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|
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if (s == NULL)
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return -1;
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|
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if (s->handshake_func == NULL) {
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/* Not properly initialized yet */
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SSL_set_accept_state(ssl);
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}
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|
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/* Ensure there is no state left over from a previous invocation */
|
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if (!SSL_clear(ssl))
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return -1;
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|
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ERR_clear_error();
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|
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rbio = SSL_get_rbio(ssl);
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wbio = SSL_get_wbio(ssl);
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|
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if (!rbio || !wbio) {
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ERR_raise(ERR_LIB_SSL, SSL_R_BIO_NOT_SET);
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return -1;
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}
|
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|
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/*
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* Note: This check deliberately excludes DTLS1_BAD_VER because that version
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* requires the MAC to be calculated *including* the first ClientHello
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* (without the cookie). Since DTLSv1_listen is stateless that cannot be
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* supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
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* SSL_accept)
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*/
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if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
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ERR_raise(ERR_LIB_SSL, SSL_R_UNSUPPORTED_SSL_VERSION);
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return -1;
|
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}
|
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|
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buf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
|
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if (buf == NULL)
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return -1;
|
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wbuf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
|
|
if (wbuf == NULL) {
|
|
OPENSSL_free(buf);
|
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return -1;
|
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}
|
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|
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do {
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/* Get a packet */
|
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|
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clear_sys_error();
|
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n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH
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+ DTLS1_RT_HEADER_LENGTH);
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if (n <= 0) {
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if (BIO_should_retry(rbio)) {
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/* Non-blocking IO */
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goto end;
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}
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ret = -1;
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goto end;
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}
|
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|
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if (!PACKET_buf_init(&pkt, buf, n)) {
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ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
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ret = -1;
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goto end;
|
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}
|
|
|
|
/*
|
|
* Parse the received record. If there are any problems with it we just
|
|
* dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
|
|
* resilient in the face of invalid records (e.g., invalid formatting,
|
|
* length, MAC, etc.). In general, invalid records SHOULD be silently
|
|
* discarded, thus preserving the association; however, an error MAY be
|
|
* logged for diagnostic purposes."
|
|
*/
|
|
|
|
/* this packet contained a partial record, dump it */
|
|
if (n < DTLS1_RT_HEADER_LENGTH) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_RECORD_TOO_SMALL);
|
|
goto end;
|
|
}
|
|
|
|
/* Get the record header */
|
|
if (!PACKET_get_1(&pkt, &rectype)
|
|
|| !PACKET_get_1(&pkt, &versmajor)
|
|
|| !PACKET_get_1(&pkt, &versminor)) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
|
|
goto end;
|
|
}
|
|
|
|
if (s->msg_callback)
|
|
s->msg_callback(0, (versmajor << 8) | versminor, SSL3_RT_HEADER, buf,
|
|
DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg);
|
|
|
|
if (rectype != SSL3_RT_HANDSHAKE) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Check record version number. We only check that the major version is
|
|
* the same.
|
|
*/
|
|
if (versmajor != DTLS1_VERSION_MAJOR) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
|
|
goto end;
|
|
}
|
|
|
|
/* Save the sequence number: 64 bits, with top 2 bytes = epoch */
|
|
if (!PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
|
|
|| !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
|
|
goto end;
|
|
}
|
|
/*
|
|
* We allow data remaining at the end of the packet because there could
|
|
* be a second record (but we ignore it)
|
|
*/
|
|
|
|
/* This is an initial ClientHello so the epoch has to be 0 */
|
|
if (seq[0] != 0 || seq[1] != 0) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
|
|
goto end;
|
|
}
|
|
|
|
/* Get a pointer to the raw message for the later callback */
|
|
data = PACKET_data(&msgpkt);
|
|
|
|
/* Finished processing the record header, now process the message */
|
|
if (!PACKET_get_1(&msgpkt, &msgtype)
|
|
|| !PACKET_get_net_3_len(&msgpkt, &msglen)
|
|
|| !PACKET_get_net_2(&msgpkt, &msgseq)
|
|
|| !PACKET_get_net_3_len(&msgpkt, &fragoff)
|
|
|| !PACKET_get_net_3_len(&msgpkt, &fraglen)
|
|
|| !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
|
|
|| PACKET_remaining(&msgpkt) != 0) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
|
|
goto end;
|
|
}
|
|
|
|
if (msgtype != SSL3_MT_CLIENT_HELLO) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
|
|
goto end;
|
|
}
|
|
|
|
/* Message sequence number can only be 0 or 1 */
|
|
if (msgseq > 2) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_INVALID_SEQUENCE_NUMBER);
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* We don't support fragment reassembly for ClientHellos whilst
|
|
* listening because that would require server side state (which is
|
|
* against the whole point of the ClientHello/HelloVerifyRequest
|
|
* mechanism). Instead we only look at the first ClientHello fragment
|
|
* and require that the cookie must be contained within it.
|
|
*/
|
|
if (fragoff != 0 || fraglen > msglen) {
|
|
/* Non initial ClientHello fragment (or bad fragment) */
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_FRAGMENTED_CLIENT_HELLO);
|
|
goto end;
|
|
}
|
|
|
|
if (s->msg_callback)
|
|
s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
|
|
fraglen + DTLS1_HM_HEADER_LENGTH, ssl,
|
|
s->msg_callback_arg);
|
|
|
|
if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Verify client version is supported
|
|
*/
|
|
if (DTLS_VERSION_LT(clientvers, (unsigned int)ssl->method->version) &&
|
|
ssl->method->version != DTLS_ANY_VERSION) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_WRONG_VERSION_NUMBER);
|
|
goto end;
|
|
}
|
|
|
|
if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
|
|
|| !PACKET_get_length_prefixed_1(&msgpayload, &session)
|
|
|| !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
|
|
/*
|
|
* Could be malformed or the cookie does not fit within the initial
|
|
* ClientHello fragment. Either way we can't handle it.
|
|
*/
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Check if we have a cookie or not. If not we need to send a
|
|
* HelloVerifyRequest.
|
|
*/
|
|
if (PACKET_remaining(&cookiepkt) == 0) {
|
|
next = LISTEN_SEND_VERIFY_REQUEST;
|
|
} else {
|
|
/*
|
|
* We have a cookie, so lets check it.
|
|
*/
|
|
if (ssl->ctx->app_verify_cookie_cb == NULL) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
|
|
/* This is fatal */
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
if (ssl->ctx->app_verify_cookie_cb(ssl, PACKET_data(&cookiepkt),
|
|
(unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
|
|
/*
|
|
* We treat invalid cookies in the same was as no cookie as
|
|
* per RFC6347
|
|
*/
|
|
next = LISTEN_SEND_VERIFY_REQUEST;
|
|
} else {
|
|
/* Cookie verification succeeded */
|
|
next = LISTEN_SUCCESS;
|
|
}
|
|
}
|
|
|
|
if (next == LISTEN_SEND_VERIFY_REQUEST) {
|
|
WPACKET wpkt;
|
|
unsigned int version;
|
|
size_t wreclen;
|
|
|
|
/*
|
|
* There was no cookie in the ClientHello so we need to send a
|
|
* HelloVerifyRequest. If this fails we do not worry about trying
|
|
* to resend, we just drop it.
|
|
*/
|
|
|
|
/* Generate the cookie */
|
|
if (ssl->ctx->app_gen_cookie_cb == NULL ||
|
|
ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0 ||
|
|
cookielen > 255) {
|
|
ERR_raise(ERR_LIB_SSL, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
|
|
/* This is fatal */
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Special case: for hello verify request, client version 1.0 and we
|
|
* haven't decided which version to use yet send back using version
|
|
* 1.0 header: otherwise some clients will ignore it.
|
|
*/
|
|
version = (ssl->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
|
|
: s->version;
|
|
|
|
/* Construct the record and message headers */
|
|
if (!WPACKET_init_static_len(&wpkt,
|
|
wbuf,
|
|
ssl_get_max_send_fragment(s)
|
|
+ DTLS1_RT_HEADER_LENGTH,
|
|
0)
|
|
|| !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
|
|
|| !WPACKET_put_bytes_u16(&wpkt, version)
|
|
/*
|
|
* Record sequence number is always the same as in the
|
|
* received ClientHello
|
|
*/
|
|
|| !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
|
|
/* End of record, start sub packet for message */
|
|
|| !WPACKET_start_sub_packet_u16(&wpkt)
|
|
/* Message type */
|
|
|| !WPACKET_put_bytes_u8(&wpkt,
|
|
DTLS1_MT_HELLO_VERIFY_REQUEST)
|
|
/*
|
|
* Message length - doesn't follow normal TLS convention:
|
|
* the length isn't the last thing in the message header.
|
|
* We'll need to fill this in later when we know the
|
|
* length. Set it to zero for now
|
|
*/
|
|
|| !WPACKET_put_bytes_u24(&wpkt, 0)
|
|
/*
|
|
* Message sequence number is always 0 for a
|
|
* HelloVerifyRequest
|
|
*/
|
|
|| !WPACKET_put_bytes_u16(&wpkt, 0)
|
|
/*
|
|
* We never fragment a HelloVerifyRequest, so fragment
|
|
* offset is 0
|
|
*/
|
|
|| !WPACKET_put_bytes_u24(&wpkt, 0)
|
|
/*
|
|
* Fragment length is the same as message length, but
|
|
* this *is* the last thing in the message header so we
|
|
* can just start a sub-packet. No need to come back
|
|
* later for this one.
|
|
*/
|
|
|| !WPACKET_start_sub_packet_u24(&wpkt)
|
|
/* Create the actual HelloVerifyRequest body */
|
|
|| !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
|
|
/* Close message body */
|
|
|| !WPACKET_close(&wpkt)
|
|
/* Close record body */
|
|
|| !WPACKET_close(&wpkt)
|
|
|| !WPACKET_get_total_written(&wpkt, &wreclen)
|
|
|| !WPACKET_finish(&wpkt)) {
|
|
ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
|
|
WPACKET_cleanup(&wpkt);
|
|
/* This is fatal */
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Fix up the message len in the message header. Its the same as the
|
|
* fragment len which has been filled in by WPACKET, so just copy
|
|
* that. Destination for the message len is after the record header
|
|
* plus one byte for the message content type. The source is the
|
|
* last 3 bytes of the message header
|
|
*/
|
|
memcpy(&wbuf[DTLS1_RT_HEADER_LENGTH + 1],
|
|
&wbuf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
|
|
3);
|
|
|
|
if (s->msg_callback)
|
|
s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
|
|
DTLS1_RT_HEADER_LENGTH, ssl,
|
|
s->msg_callback_arg);
|
|
|
|
if ((tmpclient = BIO_ADDR_new()) == NULL) {
|
|
ERR_raise(ERR_LIB_SSL, ERR_R_BIO_LIB);
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* This is unnecessary if rbio and wbio are one and the same - but
|
|
* maybe they're not. We ignore errors here - some BIOs do not
|
|
* support this.
|
|
*/
|
|
if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
|
|
(void)BIO_dgram_set_peer(wbio, tmpclient);
|
|
}
|
|
BIO_ADDR_free(tmpclient);
|
|
tmpclient = NULL;
|
|
|
|
if (BIO_write(wbio, wbuf, wreclen) < (int)wreclen) {
|
|
if (BIO_should_retry(wbio)) {
|
|
/*
|
|
* Non-blocking IO...but we're stateless, so we're just
|
|
* going to drop this packet.
|
|
*/
|
|
goto end;
|
|
}
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
|
|
if (BIO_flush(wbio) <= 0) {
|
|
if (BIO_should_retry(wbio)) {
|
|
/*
|
|
* Non-blocking IO...but we're stateless, so we're just
|
|
* going to drop this packet.
|
|
*/
|
|
goto end;
|
|
}
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
}
|
|
} while (next != LISTEN_SUCCESS);
|
|
|
|
/*
|
|
* Set expected sequence numbers to continue the handshake.
|
|
*/
|
|
s->d1->handshake_read_seq = 1;
|
|
s->d1->handshake_write_seq = 1;
|
|
s->d1->next_handshake_write_seq = 1;
|
|
s->rlayer.wrlmethod->increment_sequence_ctr(s->rlayer.wrl);
|
|
|
|
/*
|
|
* We are doing cookie exchange, so make sure we set that option in the
|
|
* SSL object
|
|
*/
|
|
SSL_set_options(ssl, SSL_OP_COOKIE_EXCHANGE);
|
|
|
|
/*
|
|
* Tell the state machine that we've done the initial hello verify
|
|
* exchange
|
|
*/
|
|
ossl_statem_set_hello_verify_done(s);
|
|
|
|
/*
|
|
* Some BIOs may not support this. If we fail we clear the client address
|
|
*/
|
|
if (BIO_dgram_get_peer(rbio, client) <= 0)
|
|
BIO_ADDR_clear(client);
|
|
|
|
/* Buffer the record for use by the record layer */
|
|
if (BIO_write(s->rlayer.rrlnext, buf, n) != n) {
|
|
ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
|
|
/*
|
|
* Reset the record layer - but this time we can use the record we just
|
|
* buffered in s->rlayer.rrlnext
|
|
*/
|
|
if (!ssl_set_new_record_layer(s,
|
|
DTLS_ANY_VERSION,
|
|
OSSL_RECORD_DIRECTION_READ,
|
|
OSSL_RECORD_PROTECTION_LEVEL_NONE, NULL, 0,
|
|
NULL, 0, NULL, 0, NULL, 0, NULL, 0,
|
|
NID_undef, NULL, NULL, NULL)) {
|
|
/* SSLfatal already called */
|
|
ret = -1;
|
|
goto end;
|
|
}
|
|
|
|
ret = 1;
|
|
end:
|
|
BIO_ADDR_free(tmpclient);
|
|
OPENSSL_free(buf);
|
|
OPENSSL_free(wbuf);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static int dtls1_handshake_write(SSL_CONNECTION *s)
|
|
{
|
|
return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
|
|
}
|
|
|
|
int dtls1_shutdown(SSL *s)
|
|
{
|
|
int ret;
|
|
#ifndef OPENSSL_NO_SCTP
|
|
BIO *wbio;
|
|
SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL_ONLY(s);
|
|
|
|
if (s == NULL)
|
|
return -1;
|
|
|
|
wbio = SSL_get_wbio(s);
|
|
if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
|
|
!(sc->shutdown & SSL_SENT_SHUTDOWN)) {
|
|
ret = BIO_dgram_sctp_wait_for_dry(wbio);
|
|
if (ret < 0)
|
|
return -1;
|
|
|
|
if (ret == 0)
|
|
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
|
|
NULL);
|
|
}
|
|
#endif
|
|
ret = ssl3_shutdown(s);
|
|
#ifndef OPENSSL_NO_SCTP
|
|
BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
int dtls1_query_mtu(SSL_CONNECTION *s)
|
|
{
|
|
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
|
|
|
|
if (s->d1->link_mtu) {
|
|
s->d1->mtu =
|
|
s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
|
|
s->d1->link_mtu = 0;
|
|
}
|
|
|
|
/* AHA! Figure out the MTU, and stick to the right size */
|
|
if (s->d1->mtu < dtls1_min_mtu(s)) {
|
|
if (!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
|
|
s->d1->mtu =
|
|
BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
|
|
|
|
/*
|
|
* I've seen the kernel return bogus numbers when it doesn't know
|
|
* (initial write), so just make sure we have a reasonable number
|
|
*/
|
|
if (s->d1->mtu < dtls1_min_mtu(s)) {
|
|
/* Set to min mtu */
|
|
s->d1->mtu = dtls1_min_mtu(s);
|
|
BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SET_MTU,
|
|
(long)s->d1->mtu, NULL);
|
|
}
|
|
} else
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static size_t dtls1_link_min_mtu(void)
|
|
{
|
|
return (g_probable_mtu[(sizeof(g_probable_mtu) /
|
|
sizeof(g_probable_mtu[0])) - 1]);
|
|
}
|
|
|
|
size_t dtls1_min_mtu(SSL_CONNECTION *s)
|
|
{
|
|
SSL *ssl = SSL_CONNECTION_GET_SSL(s);
|
|
|
|
return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
|
|
}
|
|
|
|
size_t DTLS_get_data_mtu(const SSL *ssl)
|
|
{
|
|
size_t mac_overhead, int_overhead, blocksize, ext_overhead;
|
|
const SSL_CIPHER *ciph = SSL_get_current_cipher(ssl);
|
|
size_t mtu;
|
|
const SSL_CONNECTION *s = SSL_CONNECTION_FROM_CONST_SSL_ONLY(ssl);
|
|
|
|
if (s == NULL)
|
|
return 0;
|
|
|
|
mtu = s->d1->mtu;
|
|
|
|
if (ciph == NULL)
|
|
return 0;
|
|
|
|
if (!ssl_cipher_get_overhead(ciph, &mac_overhead, &int_overhead,
|
|
&blocksize, &ext_overhead))
|
|
return 0;
|
|
|
|
if (SSL_READ_ETM(s))
|
|
ext_overhead += mac_overhead;
|
|
else
|
|
int_overhead += mac_overhead;
|
|
|
|
/* Subtract external overhead (e.g. IV/nonce, separate MAC) */
|
|
if (ext_overhead + DTLS1_RT_HEADER_LENGTH >= mtu)
|
|
return 0;
|
|
mtu -= ext_overhead + DTLS1_RT_HEADER_LENGTH;
|
|
|
|
/* Round encrypted payload down to cipher block size (for CBC etc.)
|
|
* No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
|
|
if (blocksize)
|
|
mtu -= (mtu % blocksize);
|
|
|
|
/* Subtract internal overhead (e.g. CBC padding len byte) */
|
|
if (int_overhead >= mtu)
|
|
return 0;
|
|
mtu -= int_overhead;
|
|
|
|
return mtu;
|
|
}
|
|
|
|
void DTLS_set_timer_cb(SSL *ssl, DTLS_timer_cb cb)
|
|
{
|
|
SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
|
|
|
|
if (s == NULL)
|
|
return;
|
|
|
|
s->d1->timer_cb = cb;
|
|
}
|