/* ssl/d1_lib.c */

/*

 * DTLS implementation written by Nagendra Modadugu

 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.

 */

/* ====================================================================

 * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stdio.h>

#define USE_SOCKETS

#include <openssl/objects.h>

#include "ssl_locl.h"

#if defined(OPENSSL_SYS_VMS)

# include <sys/timeb.h>

#endif

static void get_current_time(struct timeval *t);

static void dtls1_set_handshake_header(SSL *s, int type, unsigned long len);

static int dtls1_handshake_write(SSL *s);

const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;

int dtls1_listen(SSL *s, struct sockaddr *client);

SSL3_ENC_METHOD DTLSv1_enc_data = {

    tls1_enc,

    tls1_mac,

    tls1_setup_key_block,

    tls1_generate_master_secret,

    tls1_change_cipher_state,

    tls1_final_finish_mac,

    TLS1_FINISH_MAC_LENGTH,

    tls1_cert_verify_mac,

    TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,

    TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,

    tls1_alert_code,

    tls1_export_keying_material,

    SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,

    DTLS1_HM_HEADER_LENGTH,

    dtls1_set_handshake_header,

    dtls1_handshake_write

};

SSL3_ENC_METHOD DTLSv1_2_enc_data = {

    tls1_enc,

    tls1_mac,

    tls1_setup_key_block,

    tls1_generate_master_secret,

    tls1_change_cipher_state,

    tls1_final_finish_mac,

    TLS1_FINISH_MAC_LENGTH,

    tls1_cert_verify_mac,

    TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,

    TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,

    tls1_alert_code,

    tls1_export_keying_material,

    SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS

        | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,

    DTLS1_HM_HEADER_LENGTH,

    dtls1_set_handshake_header,

    dtls1_handshake_write

};

long dtls1_default_timeout(void)

{

    /*

     * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for

     * http, the cache would over fill

     */

    return (60 * 60 * 2);

}

int dtls1_new(SSL *s)

{

    DTLS1_STATE *d1;

    if (!ssl3_new(s))

        return (0);

    if ((d1 = OPENSSL_malloc(sizeof *d1)) == NULL)

        return (0);

    memset(d1, 0, sizeof *d1);

    /* d1->handshake_epoch=0; */

    d1->unprocessed_rcds.q = pqueue_new();

    d1->processed_rcds.q = pqueue_new();

    d1->buffered_messages = pqueue_new();

    d1->sent_messages = pqueue_new();

    d1->buffered_app_data.q = pqueue_new();

    if (s->server) {

        d1->cookie_len = sizeof(s->d1->cookie);

    }

    d1->link_mtu = 0;

    d1->mtu = 0;

    if (!d1->unprocessed_rcds.q || !d1->processed_rcds.q

        || !d1->buffered_messages || !d1->sent_messages

        || !d1->buffered_app_data.q) {

        if (d1->unprocessed_rcds.q)

            pqueue_free(d1->unprocessed_rcds.q);

        if (d1->processed_rcds.q)

            pqueue_free(d1->processed_rcds.q);

        if (d1->buffered_messages)

            pqueue_free(d1->buffered_messages);

        if (d1->sent_messages)

            pqueue_free(d1->sent_messages);

        if (d1->buffered_app_data.q)

            pqueue_free(d1->buffered_app_data.q);

        OPENSSL_free(d1);

        return (0);

    }

    s->d1 = d1;

    s->method->ssl_clear(s);

    return (1);

}

static void dtls1_clear_queues(SSL *s)

{

    pitem *item = NULL;

    DTLS1_RECORD_DATA *rdata;

    while ((item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL) {

        rdata = (DTLS1_RECORD_DATA *)item->data;

        if (rdata->rbuf.buf) {

            OPENSSL_free(rdata->rbuf.buf);

        }

        OPENSSL_free(item->data);

        pitem_free(item);

    }

    while ((item = pqueue_pop(s->d1->processed_rcds.q)) != NULL) {

        rdata = (DTLS1_RECORD_DATA *)item->data;

        if (rdata->rbuf.buf) {

            OPENSSL_free(rdata->rbuf.buf);

        }

        OPENSSL_free(item->data);

        pitem_free(item);

    }

    while ((item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL) {

        rdata = (DTLS1_RECORD_DATA *)item->data;

        if (rdata->rbuf.buf) {

            OPENSSL_free(rdata->rbuf.buf);

        }

        OPENSSL_free(item->data);

        pitem_free(item);

    }

    dtls1_clear_received_buffer(s);

    dtls1_clear_sent_buffer(s);

}

void dtls1_clear_received_buffer(SSL *s)

{

    pitem *item = NULL;

    hm_fragment *frag = NULL;

    while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {

        frag = (hm_fragment *)item->data;

        dtls1_hm_fragment_free(frag);

        pitem_free(item);

    }

}

void dtls1_clear_sent_buffer(SSL *s)

{

    pitem *item = NULL;

    hm_fragment *frag = NULL;

    while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {

        frag = (hm_fragment *)item->data;

        dtls1_hm_fragment_free(frag);

        pitem_free(item);

    }

}

void dtls1_free(SSL *s)

{

    ssl3_free(s);

    dtls1_clear_queues(s);

    pqueue_free(s->d1->unprocessed_rcds.q);

    pqueue_free(s->d1->processed_rcds.q);

    pqueue_free(s->d1->buffered_messages);

    pqueue_free(s->d1->sent_messages);

    pqueue_free(s->d1->buffered_app_data.q);

    OPENSSL_free(s->d1);

    s->d1 = NULL;

}

void dtls1_clear(SSL *s)

{

    pqueue unprocessed_rcds;

    pqueue processed_rcds;

    pqueue buffered_messages;

    pqueue sent_messages;

    pqueue buffered_app_data;

    unsigned int mtu;

    unsigned int link_mtu;

    if (s->d1) {

        unprocessed_rcds = s->d1->unprocessed_rcds.q;

        processed_rcds = s->d1->processed_rcds.q;

        buffered_messages = s->d1->buffered_messages;

        sent_messages = s->d1->sent_messages;

        buffered_app_data = s->d1->buffered_app_data.q;

        mtu = s->d1->mtu;

        link_mtu = s->d1->link_mtu;

        dtls1_clear_queues(s);

        memset(s->d1, 0, sizeof(*(s->d1)));

        if (s->server) {

            s->d1->cookie_len = sizeof(s->d1->cookie);

        }

        if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {

            s->d1->mtu = mtu;

            s->d1->link_mtu = link_mtu;

        }

        s->d1->unprocessed_rcds.q = unprocessed_rcds;

        s->d1->processed_rcds.q = processed_rcds;

        s->d1->buffered_messages = buffered_messages;

        s->d1->sent_messages = sent_messages;

        s->d1->buffered_app_data.q = buffered_app_data;

    }

    ssl3_clear(s);

    if (s->options & SSL_OP_CISCO_ANYCONNECT)

        s->client_version = s->version = DTLS1_BAD_VER;

    else if (s->method->version == DTLS_ANY_VERSION)

        s->version = DTLS1_2_VERSION;

    else

        s->version = s->method->version;

}

long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)

{

    int ret = 0;

    switch (cmd) {

    case DTLS_CTRL_GET_TIMEOUT:

        if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {

            ret = 1;

        }

        break;

    case DTLS_CTRL_HANDLE_TIMEOUT:

        ret = dtls1_handle_timeout(s);

        break;

    case DTLS_CTRL_LISTEN:

        ret = dtls1_listen(s, parg);

        break;

    case SSL_CTRL_CHECK_PROTO_VERSION:

        /*

         * For library-internal use; checks that the current protocol is the

         * highest enabled version (according to s->ctx->method, as version

         * negotiation may have changed s->method).

         */

        if (s->version == s->ctx->method->version)

            return 1;

        /*

         * Apparently we're using a version-flexible SSL_METHOD (not at its

         * highest protocol version).

         */

        if (s->ctx->method->version == DTLS_method()->version) {

#if DTLS_MAX_VERSION != DTLS1_2_VERSION

# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.

#endif

            if (!(s->options & SSL_OP_NO_DTLSv1_2))

                return s->version == DTLS1_2_VERSION;

            if (!(s->options & SSL_OP_NO_DTLSv1))

                return s->version == DTLS1_VERSION;

        }

        return 0;               /* Unexpected state; fail closed. */

    case DTLS_CTRL_SET_LINK_MTU:

        if (larg < (long)dtls1_link_min_mtu())

            return 0;

        s->d1->link_mtu = larg;

        return 1;

    case DTLS_CTRL_GET_LINK_MIN_MTU:

        return (long)dtls1_link_min_mtu();

    case SSL_CTRL_SET_MTU:

        /*

         *  We may not have a BIO set yet so can't call dtls1_min_mtu()

         *  We'll have to make do with dtls1_link_min_mtu() and max overhead

         */

        if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)

            return 0;

        s->d1->mtu = larg;

        return larg;

    default:

        ret = ssl3_ctrl(s, cmd, larg, parg);

        break;

    }

    return (ret);

}

/*

 * As it's impossible to use stream ciphers in "datagram" mode, this

 * simple filter is designed to disengage them in DTLS. Unfortunately

 * there is no universal way to identify stream SSL_CIPHER, so we have

 * to explicitly list their SSL_* codes. Currently RC4 is the only one

 * available, but if new ones emerge, they will have to be added...

 */

const SSL_CIPHER *dtls1_get_cipher(unsigned int u)

{

    const SSL_CIPHER *ciph = ssl3_get_cipher(u);

    if (ciph != NULL) {

        if (ciph->algorithm_enc == SSL_RC4)

            return NULL;

    }

    return ciph;

}

void dtls1_start_timer(SSL *s)

{

#ifndef OPENSSL_NO_SCTP

    /* Disable timer for SCTP */

    if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {

        memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));

        return;

    }

#endif

    /* If timer is not set, initialize duration with 1 second */

    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {

        s->d1->timeout_duration = 1;

    }

    /* Set timeout to current time */

    get_current_time(&(s->d1->next_timeout));

    /* Add duration to current time */

    s->d1->next_timeout.tv_sec += s->d1->timeout_duration;

    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,

             &(s->d1->next_timeout));

}

struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)

{

    struct timeval timenow;

    /* If no timeout is set, just return NULL */

    if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {

        return NULL;

    }

    /* Get current time */

    get_current_time(&timenow);

    /* If timer already expired, set remaining time to 0 */

    if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||

        (s->d1->next_timeout.tv_sec == timenow.tv_sec &&

         s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {

        memset(timeleft, 0, sizeof(struct timeval));

        return timeleft;

    }

    /* Calculate time left until timer expires */

    memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));

    timeleft->tv_sec -= timenow.tv_sec;

    timeleft->tv_usec -= timenow.tv_usec;

    if (timeleft->tv_usec < 0) {

        timeleft->tv_sec--;

        timeleft->tv_usec += 1000000;

    }

    /*

     * If remaining time is less than 15 ms, set it to 0 to prevent issues

     * because of small devergences with socket timeouts.

     */

    if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {

        memset(timeleft, 0, sizeof(struct timeval));

    }

    return timeleft;

}

int dtls1_is_timer_expired(SSL *s)

{

    struct timeval timeleft;

    /* Get time left until timeout, return false if no timer running */

    if (dtls1_get_timeout(s, &timeleft) == NULL) {

        return 0;

    }

    /* Return false if timer is not expired yet */

    if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {

        return 0;

    }

    /* Timer expired, so return true */

    return 1;

}

void dtls1_double_timeout(SSL *s)

{

    s->d1->timeout_duration *= 2;

    if (s->d1->timeout_duration > 60)

        s->d1->timeout_duration = 60;

    dtls1_start_timer(s);

}

void dtls1_stop_timer(SSL *s)

{

    /* Reset everything */

    memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));

    memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));

    s->d1->timeout_duration = 1;

    BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,

             &(s->d1->next_timeout));

    /* Clear retransmission buffer */

    dtls1_clear_sent_buffer(s);

}

int dtls1_check_timeout_num(SSL *s)

{

    unsigned int mtu;

    s->d1->timeout.num_alerts++;

    /* Reduce MTU after 2 unsuccessful retransmissions */

    if (s->d1->timeout.num_alerts > 2

        && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {

        mtu =

            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,

                     NULL);

        if (mtu < s->d1->mtu)

            s->d1->mtu = mtu;

    }

    if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {

        /* fail the connection, enough alerts have been sent */

        SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);

        return -1;

    }

    return 0;

}

int dtls1_handle_timeout(SSL *s)

{

    /* if no timer is expired, don't do anything */

    if (!dtls1_is_timer_expired(s)) {

        return 0;

    }

    dtls1_double_timeout(s);

    if (dtls1_check_timeout_num(s) < 0)

        return -1;

    s->d1->timeout.read_timeouts++;

    if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {

        s->d1->timeout.read_timeouts = 1;

    }

#ifndef OPENSSL_NO_HEARTBEATS

    if (s->tlsext_hb_pending) {

        s->tlsext_hb_pending = 0;

        return dtls1_heartbeat(s);

    }

#endif

    dtls1_start_timer(s);

    return dtls1_retransmit_buffered_messages(s);

}

static void get_current_time(struct timeval *t)

{

#if defined(_WIN32)

    SYSTEMTIME st;

    union {

        unsigned __int64 ul;

        FILETIME ft;

    } now;

    GetSystemTime(&st);

    SystemTimeToFileTime(&st, &now.ft);

# ifdef  __MINGW32__

    now.ul -= 116444736000000000ULL;

# else

    now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */

# endif

    t->tv_sec = (long)(now.ul / 10000000);

    t->tv_usec = ((int)(now.ul % 10000000)) / 10;

#elif defined(OPENSSL_SYS_VMS)

    struct timeb tb;

    ftime(&tb);

    t->tv_sec = (long)tb.time;

    t->tv_usec = (long)tb.millitm * 1000;

#else

    gettimeofday(t, NULL);

#endif

}

int dtls1_listen(SSL *s, struct sockaddr *client)

{

    int ret;

    /* Ensure there is no state left over from a previous invocation */

    SSL_clear(s);

    SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);

    s->d1->listen = 1;

    ret = SSL_accept(s);

    if (ret <= 0)

        return ret;

    (void)BIO_dgram_get_peer(SSL_get_rbio(s), client);

    return 1;

}

static void dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)

{

    unsigned char *p = (unsigned char *)s->init_buf->data;

    dtls1_set_message_header(s, p, htype, len, 0, len);

    s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;

    s->init_off = 0;

    /* Buffer the message to handle re-xmits */

    dtls1_buffer_message(s, 0);

}

static int dtls1_handshake_write(SSL *s)

{

    return dtls1_do_write(s, SSL3_RT_HANDSHAKE);

}