/*

 * Copyright 2005-2018 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the OpenSSL license (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include "e_os.h"

#include <stdio.h>

#include <openssl/objects.h>

#include <openssl/rand.h>

#include "ssl_local.h"

static void get_current_time(struct timeval *t);

static int dtls1_handshake_write(SSL *s);

static size_t dtls1_link_min_mtu(void);

/* XDTLS:  figure out the right values */

static const size_t g_probable_mtu[] = { 1500, 512, 256 };

const 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,

    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_set_handshake_header,

    dtls1_close_construct_packet,

    dtls1_handshake_write

};

const 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,

    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_set_handshake_header,

    dtls1_close_construct_packet,

    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 (!DTLS_RECORD_LAYER_new(&s->rlayer)) {

        return 0;

    }

    if (!ssl3_new(s))

        return 0;

    if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {

        ssl3_free(s);

        return 0;

    }

    d1->buffered_messages = pqueue_new();

    d1->sent_messages = pqueue_new();

    if (s->server) {

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

    }

    d1->link_mtu = 0;

    d1->mtu = 0;

    if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {

        pqueue_free(d1->buffered_messages);

        pqueue_free(d1->sent_messages);

        OPENSSL_free(d1);

        ssl3_free(s);

        return 0;

    }

    s->d1 = d1;

    if (!s->method->ssl_clear(s))

        return 0;

    return 1;

}

static void dtls1_clear_queues(SSL *s)

{

    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)

{

    DTLS_RECORD_LAYER_free(&s->rlayer);

    ssl3_free(s);

    dtls1_clear_queues(s);

    pqueue_free(s->d1->buffered_messages);

    pqueue_free(s->d1->sent_messages);

    OPENSSL_free(s->d1);

    s->d1 = NULL;

}

int dtls1_clear(SSL *s)

{

    pqueue *buffered_messages;

    pqueue *sent_messages;

    size_t mtu;

    size_t link_mtu;

    DTLS_RECORD_LAYER_clear(&s->rlayer);

    if (s->d1) {

        DTLS_timer_cb timer_cb = s->d1->timer_cb;

        buffered_messages = s->d1->buffered_messages;

        sent_messages = s->d1->sent_messages;

        mtu = s->d1->mtu;

        link_mtu = s->d1->link_mtu;

        dtls1_clear_queues(s);

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

        /* Restore the timer callback from previous state */

        s->d1->timer_cb = timer_cb;

        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->buffered_messages = buffered_messages;

        s->d1->sent_messages = sent_messages;

    }

    if (!ssl3_clear(s))

        return 0;

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

        s->version = DTLS_MAX_VERSION;

#ifndef OPENSSL_NO_DTLS1_METHOD

    else if (s->options & SSL_OP_CISCO_ANYCONNECT)

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

#endif

    else

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

    return 1;

}

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_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;

}

void dtls1_start_timer(SSL *s)

{

    unsigned int sec, usec;

#ifndef OPENSSL_NO_SCTP

    /* Disable timer for SCTP */

    if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {

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

        return;

    }

#endif

    /*

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

     * a user-specified value if the timer callback is installed.

     */

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

        if (s->d1->timer_cb != NULL)

            s->d1->timeout_duration_us = s->d1->timer_cb(s, 0);

        else

            s->d1->timeout_duration_us = 1000000;

    }

    /* Set timeout to current time */

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

    /* Add duration to current time */

    sec  = s->d1->timeout_duration_us / 1000000;

    usec = s->d1->timeout_duration_us - (sec * 1000000);

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

    s->d1->next_timeout.tv_usec += usec;

    if (s->d1->next_timeout.tv_usec >= 1000000) {

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

        s->d1->next_timeout.tv_usec -= 1000000;

    }

    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(*timeleft));

        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 divergences with socket timeouts.

     */

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

        memset(timeleft, 0, sizeof(*timeleft));

    }

    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_us *= 2;

    if (s->d1->timeout_duration_us > 60000000)

        s->d1->timeout_duration_us = 60000000;

    dtls1_start_timer(s);

}

void dtls1_stop_timer(SSL *s)

{

    /* Reset everything */

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

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

    s->d1->timeout_duration_us = 1000000;

    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)

{

    size_t 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 */

        SSLfatal(s, SSL_AD_NO_ALERT, 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;

    }

    if (s->d1->timer_cb != NULL)

        s->d1->timeout_duration_us = s->d1->timer_cb(s, s->d1->timeout_duration_us);

    else

        dtls1_double_timeout(s);

    if (dtls1_check_timeout_num(s) < 0) {

        /* SSLfatal() already called */

        return -1;

    }

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

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

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

    }

    dtls1_start_timer(s);

    /* Calls SSLfatal() if required */

    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);

    /* re-bias to 1/1/1970 */

# ifdef  __MINGW32__

    now.ul -= 116444736000000000ULL;

# else

    /* *INDENT-OFF* */

    now.ul -= 116444736000000000UI64;

    /* *INDENT-ON* */

# endif

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

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

#else

    gettimeofday(t, NULL);

#endif

}

#define LISTEN_SUCCESS              2

#define LISTEN_SEND_VERIFY_REQUEST  1

#ifndef OPENSSL_NO_SOCK

int DTLSv1_listen(SSL *s, BIO_ADDR *client)

{

    int next, n, ret = 0;

    unsigned char cookie[DTLS1_COOKIE_LENGTH];

    unsigned char seq[SEQ_NUM_SIZE];

    const unsigned char *data;

    unsigned char *buf, *wbuf;

    size_t fragoff, fraglen, msglen, reclen, align = 0;

    unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;

    BIO *rbio, *wbio;

    BIO_ADDR *tmpclient = NULL;

    PACKET pkt, msgpkt, msgpayload, session, cookiepkt;

    if (s->handshake_func == NULL) {

        /* Not properly initialized yet */

        SSL_set_accept_state(s);

    }

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

    if (!SSL_clear(s))

        return -1;

    ERR_clear_error();

    rbio = SSL_get_rbio(s);

    wbio = SSL_get_wbio(s);

    if (!rbio || !wbio) {

        SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);

        return -1;

    }

    /*

     * Note: This check deliberately excludes DTLS1_BAD_VER because that version

     * requires the MAC to be calculated *including* the first ClientHello

     * (without the cookie). Since DTLSv1_listen is stateless that cannot be

     * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via

     * SSL_accept)

     */

    if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {

        SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);

        return -1;

    }

    if (!ssl3_setup_buffers(s)) {

        /* SSLerr already called */

        return -1;

    }

    buf = RECORD_LAYER_get_rbuf(&s->rlayer)->buf;

    wbuf = RECORD_LAYER_get_wbuf(&s->rlayer)[0].buf;

#if defined(SSL3_ALIGN_PAYLOAD)

# if SSL3_ALIGN_PAYLOAD != 0

    /*

     * Using SSL3_RT_HEADER_LENGTH here instead of DTLS1_RT_HEADER_LENGTH for

     * consistency with ssl3_read_n. In practice it should make no difference

     * for sensible values of SSL3_ALIGN_PAYLOAD because the difference between

     * SSL3_RT_HEADER_LENGTH and DTLS1_RT_HEADER_LENGTH is exactly 8

     */

    align = (size_t)buf + SSL3_RT_HEADER_LENGTH;

    align = SSL3_ALIGN_PAYLOAD - 1 - ((align - 1) % SSL3_ALIGN_PAYLOAD);

# endif

#endif

    buf += align;

    do {

        /* Get a packet */

        clear_sys_error();

        n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH

                                + DTLS1_RT_HEADER_LENGTH);

        if (n <= 0) {

            if (BIO_should_retry(rbio)) {

                /* Non-blocking IO */

                goto end;

            }

            return -1;

        }

        if (!PACKET_buf_init(&pkt, buf, n)) {

            SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);

            return -1;

        }

        /*

         * 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) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);

            goto end;

        }

        if (s->msg_callback)

            s->msg_callback(0, 0, SSL3_RT_HEADER, buf,

                            DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);

        /* Get the record header */

        if (!PACKET_get_1(&pkt, &rectype)

            || !PACKET_get_1(&pkt, &versmajor)) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);

            goto end;

        }

        if (rectype != SSL3_RT_HANDSHAKE) {

            SSLerr(SSL_F_DTLSV1_LISTEN, 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) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);

            goto end;

        }

        if (!PACKET_forward(&pkt, 1)

            /* Save the sequence number: 64 bits, with top 2 bytes = epoch */

            || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)

            || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);

            goto end;

        }

        reclen = PACKET_remaining(&msgpkt);

        /*

         * 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) {

            SSLerr(SSL_F_DTLSV1_LISTEN, 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) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);

            goto end;

        }

        if (msgtype != SSL3_MT_CLIENT_HELLO) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);

            goto end;

        }

        /* Message sequence number can only be 0 or 1 */

        if (msgseq > 2) {

            SSLerr(SSL_F_DTLSV1_LISTEN, 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) */

            SSLerr(SSL_F_DTLSV1_LISTEN, 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, s,

                            s->msg_callback_arg);

        if (!PACKET_get_net_2(&msgpayload, &clientvers)) {

            SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);

            goto end;

        }

        /*

         * Verify client version is supported

         */

        if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&

            s->method->version != DTLS_ANY_VERSION) {

            SSLerr(SSL_F_DTLSV1_LISTEN, 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.

             */

            SSLerr(SSL_F_DTLSV1_LISTEN, 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 (s->ctx->app_verify_cookie_cb == NULL) {

                SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);

                /* This is fatal */

                return -1;

            }

            if (s->ctx->app_verify_cookie_cb(s, 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 (s->ctx->app_gen_cookie_cb == NULL ||

                s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||

                cookielen > 255) {

                SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);

                /* This is fatal */

                return -1;

            }

            /*

             * 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 = (s->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)) {

                SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);

                WPACKET_cleanup(&wpkt);

                /* This is fatal */

                return -1;

            }

            /*

             * 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, s, s->msg_callback_arg);

            if ((tmpclient = BIO_ADDR_new()) == NULL) {

                SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);

                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;

            /* TODO(size_t): convert this call */

            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;

                }

                return -1;

            }

            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;

                }

                return -1;

            }

        }

    } 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;

    DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);

    /*

     * We are doing cookie exchange, so make sure we set that option in the

     * SSL object

     */

    SSL_set_options(s, 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 in the processed_rcds queue */

    if (!dtls_buffer_listen_record(s, reclen, seq, align))

        return -1;

    ret = 1;

 end:

    BIO_ADDR_free(tmpclient);

    return ret;

}

#endif

static int dtls1_handshake_write(SSL *s)

{

    return dtls1_do_write(s, SSL3_RT_HANDSHAKE);

}

int dtls1_shutdown(SSL *s)

{

    int ret;

#ifndef OPENSSL_NO_SCTP

    BIO *wbio;

    wbio = SSL_get_wbio(s);

    if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&

        !(s->shutdown & SSL_SENT_SHUTDOWN)) {

        ret = BIO_dgram_sctp_wait_for_dry(wbio);

        if (ret < 0)

            return -1;

        if (ret == 0)