openssl: Move to a module and split thirdparty lib

Same rationale as the previous commits.

1 files changed, 1921 insertions, 0 deletions

diff --git a/thirdparty/openssl/ssl/d1_pkt.c b/thirdparty/openssl/ssl/d1_pkt.c
new file mode 100644
index 0000000000..fe30ec7d00
--- /dev/null
+++ b/thirdparty/openssl/ssl/d1_pkt.c
@@ -0,0 +1,1921 @@
+/* ssl/d1_pkt.c */
+/*
+ * DTLS implementation written by Nagendra Modadugu
+ * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
+ */
+/* ====================================================================
+ * Copyright (c) 1998-2005 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).
+ *
+ */
+/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
+ * All rights reserved.
+ *
+ * This package is an SSL implementation written
+ * by Eric Young (eay@cryptsoft.com).
+ * The implementation was written so as to conform with Netscapes SSL.
+ *
+ * This library is free for commercial and non-commercial use as long as
+ * the following conditions are aheared to.  The following conditions
+ * apply to all code found in this distribution, be it the RC4, RSA,
+ * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
+ * included with this distribution is covered by the same copyright terms
+ * except that the holder is Tim Hudson (tjh@cryptsoft.com).
+ *
+ * Copyright remains Eric Young's, and as such any Copyright notices in
+ * the code are not to be removed.
+ * If this package is used in a product, Eric Young should be given attribution
+ * as the author of the parts of the library used.
+ * This can be in the form of a textual message at program startup or
+ * in documentation (online or textual) provided with the package.
+ *
+ * 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 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 acknowledgement:
+ *    "This product includes cryptographic software written by
+ *     Eric Young (eay@cryptsoft.com)"
+ *    The word 'cryptographic' can be left out if the rouines from the library
+ *    being used are not cryptographic related :-).
+ * 4. If you include any Windows specific code (or a derivative thereof) from
+ *    the apps directory (application code) you must include an acknowledgement:
+ *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
+ * ANY EXPRESS 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 AUTHOR OR 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.
+ *
+ * The licence and distribution terms for any publically available version or
+ * derivative of this code cannot be changed.  i.e. this code cannot simply be
+ * copied and put under another distribution licence
+ * [including the GNU Public Licence.]
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#define USE_SOCKETS
+#include "ssl_locl.h"
+#include <openssl/evp.h>
+#include <openssl/buffer.h>
+#include <openssl/pqueue.h>
+#include <openssl/rand.h>
+
+/* mod 128 saturating subtract of two 64-bit values in big-endian order */
+static int satsub64be(const unsigned char *v1, const unsigned char *v2)
+{
+    int ret, sat, brw, i;
+
+    if (sizeof(long) == 8)
+        do {
+            const union {
+                long one;
+                char little;
+            } is_endian = {
+                1
+            };
+            long l;
+
+            if (is_endian.little)
+                break;
+            /* not reached on little-endians */
+            /*
+             * following test is redundant, because input is always aligned,
+             * but I take no chances...
+             */
+            if (((size_t)v1 | (size_t)v2) & 0x7)
+                break;
+
+            l = *((long *)v1);
+            l -= *((long *)v2);
+            if (l > 128)
+                return 128;
+            else if (l < -128)
+                return -128;
+            else
+                return (int)l;
+        } while (0);
+
+    ret = (int)v1[7] - (int)v2[7];
+    sat = 0;
+    brw = ret >> 8;             /* brw is either 0 or -1 */
+    if (ret & 0x80) {
+        for (i = 6; i >= 0; i--) {
+            brw += (int)v1[i] - (int)v2[i];
+            sat |= ~brw;
+            brw >>= 8;
+        }
+    } else {
+        for (i = 6; i >= 0; i--) {
+            brw += (int)v1[i] - (int)v2[i];
+            sat |= brw;
+            brw >>= 8;
+        }
+    }
+    brw <<= 8;                  /* brw is either 0 or -256 */
+
+    if (sat & 0xff)
+        return brw | 0x80;
+    else
+        return brw + (ret & 0xFF);
+}
+
+static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
+                                   int len, int peek);
+static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
+static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
+static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
+                                      unsigned int *is_next_epoch);
+#if 0
+static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
+                                        unsigned short *priority,
+                                        unsigned long *offset);
+#endif
+static int dtls1_buffer_record(SSL *s, record_pqueue *q,
+                               unsigned char *priority);
+static int dtls1_process_record(SSL *s);
+
+/* copy buffered record into SSL structure */
+static int dtls1_copy_record(SSL *s, pitem *item)
+{
+    DTLS1_RECORD_DATA *rdata;
+
+    rdata = (DTLS1_RECORD_DATA *)item->data;
+
+    if (s->s3->rbuf.buf != NULL)
+        OPENSSL_free(s->s3->rbuf.buf);
+
+    s->packet = rdata->packet;
+    s->packet_length = rdata->packet_length;
+    memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
+    memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
+
+    /* Set proper sequence number for mac calculation */
+    memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
+
+    return (1);
+}
+
+static int
+dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
+{
+    DTLS1_RECORD_DATA *rdata;
+    pitem *item;
+
+    /* Limit the size of the queue to prevent DOS attacks */
+    if (pqueue_size(queue->q) >= 100)
+        return 0;
+
+    rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
+    item = pitem_new(priority, rdata);
+    if (rdata == NULL || item == NULL) {
+        if (rdata != NULL)
+            OPENSSL_free(rdata);
+        if (item != NULL)
+            pitem_free(item);
+
+        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+        return -1;
+    }
+
+    rdata->packet = s->packet;
+    rdata->packet_length = s->packet_length;
+    memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
+    memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
+
+    item->data = rdata;
+
+#ifndef OPENSSL_NO_SCTP
+    /* Store bio_dgram_sctp_rcvinfo struct */
+    if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+        (s->state == SSL3_ST_SR_FINISHED_A
+         || s->state == SSL3_ST_CR_FINISHED_A)) {
+        BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
+                 sizeof(rdata->recordinfo), &rdata->recordinfo);
+    }
+#endif
+
+    s->packet = NULL;
+    s->packet_length = 0;
+    memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
+    memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
+
+    if (!ssl3_setup_buffers(s)) {
+        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+        if (rdata->rbuf.buf != NULL)
+            OPENSSL_free(rdata->rbuf.buf);
+        OPENSSL_free(rdata);
+        pitem_free(item);
+        return (-1);
+    }
+
+    /* insert should not fail, since duplicates are dropped */
+    if (pqueue_insert(queue->q, item) == NULL) {
+        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
+        if (rdata->rbuf.buf != NULL)
+            OPENSSL_free(rdata->rbuf.buf);
+        OPENSSL_free(rdata);
+        pitem_free(item);
+        return (-1);
+    }
+
+    return (1);
+}
+
+static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
+{
+    pitem *item;
+
+    item = pqueue_pop(queue->q);
+    if (item) {
+        dtls1_copy_record(s, item);
+
+        OPENSSL_free(item->data);
+        pitem_free(item);
+
+        return (1);
+    }
+
+    return (0);
+}
+
+/*
+ * retrieve a buffered record that belongs to the new epoch, i.e., not
+ * processed yet
+ */
+#define dtls1_get_unprocessed_record(s) \
+                   dtls1_retrieve_buffered_record((s), \
+                   &((s)->d1->unprocessed_rcds))
+
+/*
+ * retrieve a buffered record that belongs to the current epoch, ie,
+ * processed
+ */
+#define dtls1_get_processed_record(s) \
+                   dtls1_retrieve_buffered_record((s), \
+                   &((s)->d1->processed_rcds))
+
+static int dtls1_process_buffered_records(SSL *s)
+{
+    pitem *item;
+
+    item = pqueue_peek(s->d1->unprocessed_rcds.q);
+    if (item) {
+        /* Check if epoch is current. */
+        if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
+            return (1);         /* Nothing to do. */
+
+        /* Process all the records. */
+        while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
+            dtls1_get_unprocessed_record(s);
+            if (!dtls1_process_record(s))
+                return (0);
+            if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
+                                    s->s3->rrec.seq_num) < 0)
+                return -1;
+        }
+    }
+
+    /*
+     * sync epoch numbers once all the unprocessed records have been
+     * processed
+     */
+    s->d1->processed_rcds.epoch = s->d1->r_epoch;
+    s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
+
+    return (1);
+}
+
+#if 0
+
+static int dtls1_get_buffered_record(SSL *s)
+{
+    pitem *item;
+    PQ_64BIT priority =
+        (((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
+        ((PQ_64BIT) s->d1->r_msg_hdr.frag_off);
+
+    /* if we're not (re)negotiating, nothing buffered */
+    if (!SSL_in_init(s))
+        return 0;
+
+    item = pqueue_peek(s->d1->rcvd_records);
+    if (item && item->priority == priority) {
+        /*
+         * Check if we've received the record of interest.  It must be a
+         * handshake record, since data records as passed up without
+         * buffering
+         */
+        DTLS1_RECORD_DATA *rdata;
+        item = pqueue_pop(s->d1->rcvd_records);
+        rdata = (DTLS1_RECORD_DATA *)item->data;
+
+        if (s->s3->rbuf.buf != NULL)
+            OPENSSL_free(s->s3->rbuf.buf);
+
+        s->packet = rdata->packet;
+        s->packet_length = rdata->packet_length;
+        memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
+        memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
+
+        OPENSSL_free(item->data);
+        pitem_free(item);
+
+        /* s->d1->next_expected_seq_num++; */
+        return (1);
+    }
+
+    return 0;
+}
+
+#endif
+
+static int dtls1_process_record(SSL *s)
+{
+    int i, al;
+    int enc_err;
+    SSL_SESSION *sess;
+    SSL3_RECORD *rr;
+    unsigned int mac_size, orig_len;
+    unsigned char md[EVP_MAX_MD_SIZE];
+
+    rr = &(s->s3->rrec);
+    sess = s->session;
+
+    /*
+     * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
+     * and we have that many bytes in s->packet
+     */
+    rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);
+
+    /*
+     * ok, we can now read from 's->packet' data into 'rr' rr->input points
+     * at rr->length bytes, which need to be copied into rr->data by either
+     * the decryption or by the decompression When the data is 'copied' into
+     * the rr->data buffer, rr->input will be pointed at the new buffer
+     */
+
+    /*
+     * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
+     * bytes of encrypted compressed stuff.
+     */
+
+    /* check is not needed I believe */
+    if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
+        al = SSL_AD_RECORD_OVERFLOW;
+        SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
+        goto f_err;
+    }
+
+    /* decrypt in place in 'rr->input' */
+    rr->data = rr->input;
+
+    enc_err = s->method->ssl3_enc->enc(s, 0);
+    /*-
+     * enc_err is:
+     *    0: (in non-constant time) if the record is publically invalid.
+     *    1: if the padding is valid
+     *   -1: if the padding is invalid
+     */
+    if (enc_err == 0) {
+        /* For DTLS we simply ignore bad packets. */
+        rr->length = 0;
+        s->packet_length = 0;
+        goto err;
+    }
+#ifdef TLS_DEBUG
+    printf("dec %d\n", rr->length);
+    {
+        unsigned int z;
+        for (z = 0; z < rr->length; z++)
+            printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
+    }
+    printf("\n");
+#endif
+
+    /* r->length is now the compressed data plus mac */
+    if ((sess != NULL) &&
+        (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
+        /* s->read_hash != NULL => mac_size != -1 */
+        unsigned char *mac = NULL;
+        unsigned char mac_tmp[EVP_MAX_MD_SIZE];
+        mac_size = EVP_MD_CTX_size(s->read_hash);
+        OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
+
+        /*
+         * kludge: *_cbc_remove_padding passes padding length in rr->type
+         */
+        orig_len = rr->length + ((unsigned int)rr->type >> 8);
+
+        /*
+         * orig_len is the length of the record before any padding was
+         * removed. This is public information, as is the MAC in use,
+         * therefore we can safely process the record in a different amount
+         * of time if it's too short to possibly contain a MAC.
+         */
+        if (orig_len < mac_size ||
+            /* CBC records must have a padding length byte too. */
+            (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+             orig_len < mac_size + 1)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
+            goto f_err;
+        }
+
+        if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
+            /*
+             * We update the length so that the TLS header bytes can be
+             * constructed correctly but we need to extract the MAC in
+             * constant time from within the record, without leaking the
+             * contents of the padding bytes.
+             */
+            mac = mac_tmp;
+            ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
+            rr->length -= mac_size;
+        } else {
+            /*
+             * In this case there's no padding, so |orig_len| equals
+             * |rec->length| and we checked that there's enough bytes for
+             * |mac_size| above.
+             */
+            rr->length -= mac_size;
+            mac = &rr->data[rr->length];
+        }
+
+        i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
+        if (i < 0 || mac == NULL
+            || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
+            enc_err = -1;
+        if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
+            enc_err = -1;
+    }
+
+    if (enc_err < 0) {
+        /* decryption failed, silently discard message */
+        rr->length = 0;
+        s->packet_length = 0;
+        goto err;
+    }
+
+    /* r->length is now just compressed */
+    if (s->expand != NULL) {
+        if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
+            al = SSL_AD_RECORD_OVERFLOW;
+            SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
+                   SSL_R_COMPRESSED_LENGTH_TOO_LONG);
+            goto f_err;
+        }
+        if (!ssl3_do_uncompress(s)) {
+            al = SSL_AD_DECOMPRESSION_FAILURE;
+            SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
+            goto f_err;
+        }
+    }
+
+    if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
+        al = SSL_AD_RECORD_OVERFLOW;
+        SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
+        goto f_err;
+    }
+
+    rr->off = 0;
+    /*-
+     * So at this point the following is true
+     * ssl->s3->rrec.type   is the type of record
+     * ssl->s3->rrec.length == number of bytes in record
+     * ssl->s3->rrec.off    == offset to first valid byte
+     * ssl->s3->rrec.data   == where to take bytes from, increment
+     *                         after use :-).
+     */
+
+    /* we have pulled in a full packet so zero things */
+    s->packet_length = 0;
+    return (1);
+
+ f_err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ err:
+    return (0);
+}
+
+/*-
+ * Call this to get a new input record.
+ * It will return <= 0 if more data is needed, normally due to an error
+ * or non-blocking IO.
+ * When it finishes, one packet has been decoded and can be found in
+ * ssl->s3->rrec.type    - is the type of record
+ * ssl->s3->rrec.data,   - data
+ * ssl->s3->rrec.length, - number of bytes
+ */
+/* used only by dtls1_read_bytes */
+int dtls1_get_record(SSL *s)
+{
+    int ssl_major, ssl_minor;
+    int i, n;
+    SSL3_RECORD *rr;
+    unsigned char *p = NULL;
+    unsigned short version;
+    DTLS1_BITMAP *bitmap;
+    unsigned int is_next_epoch;
+
+    rr = &(s->s3->rrec);
+
+    /*
+     * The epoch may have changed.  If so, process all the pending records.
+     * This is a non-blocking operation.
+     */
+    if (dtls1_process_buffered_records(s) < 0)
+        return -1;
+
+    /* if we're renegotiating, then there may be buffered records */
+    if (dtls1_get_processed_record(s))
+        return 1;
+
+    /* get something from the wire */
+ again:
+    /* check if we have the header */
+    if ((s->rstate != SSL_ST_READ_BODY) ||
+        (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
+        n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
+        /* read timeout is handled by dtls1_read_bytes */
+        if (n <= 0)
+            return (n);         /* error or non-blocking */
+
+        /* this packet contained a partial record, dump it */
+        if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
+            s->packet_length = 0;
+            goto again;
+        }
+
+        s->rstate = SSL_ST_READ_BODY;
+
+        p = s->packet;
+
+        if (s->msg_callback)
+            s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
+                            s, s->msg_callback_arg);
+
+        /* Pull apart the header into the DTLS1_RECORD */
+        rr->type = *(p++);
+        ssl_major = *(p++);
+        ssl_minor = *(p++);
+        version = (ssl_major << 8) | ssl_minor;
+
+        /* sequence number is 64 bits, with top 2 bytes = epoch */
+        n2s(p, rr->epoch);
+
+        memcpy(&(s->s3->read_sequence[2]), p, 6);
+        p += 6;
+
+        n2s(p, rr->length);
+
+        /* Lets check version */
+        if (!s->first_packet) {
+            if (version != s->version) {
+                /* unexpected version, silently discard */
+                rr->length = 0;
+                s->packet_length = 0;
+                goto again;
+            }
+        }
+
+        if ((version & 0xff00) != (s->version & 0xff00)) {
+            /* wrong version, silently discard record */
+            rr->length = 0;
+            s->packet_length = 0;
+            goto again;
+        }
+
+        if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
+            /* record too long, silently discard it */
+            rr->length = 0;
+            s->packet_length = 0;
+            goto again;
+        }
+
+        /* now s->rstate == SSL_ST_READ_BODY */
+    }
+
+    /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
+
+    if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
+        /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
+        i = rr->length;
+        n = ssl3_read_n(s, i, i, 1);
+        /* this packet contained a partial record, dump it */
+        if (n != i) {
+            rr->length = 0;
+            s->packet_length = 0;
+            goto again;
+        }
+
+        /*
+         * now n == rr->length, and s->packet_length ==
+         * DTLS1_RT_HEADER_LENGTH + rr->length
+         */
+    }
+    s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
+
+    /* match epochs.  NULL means the packet is dropped on the floor */
+    bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
+    if (bitmap == NULL) {
+        rr->length = 0;
+        s->packet_length = 0;   /* dump this record */
+        goto again;             /* get another record */
+    }
+#ifndef OPENSSL_NO_SCTP
+    /* Only do replay check if no SCTP bio */
+    if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
+#endif
+        /*
+         * Check whether this is a repeat, or aged record. Don't check if
+         * we're listening and this message is a ClientHello. They can look
+         * as if they're replayed, since they arrive from different
+         * connections and would be dropped unnecessarily.
+         */
+        if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
+              s->packet_length > DTLS1_RT_HEADER_LENGTH &&
+              s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
+            !dtls1_record_replay_check(s, bitmap)) {
+            rr->length = 0;
+            s->packet_length = 0; /* dump this record */
+            goto again;         /* get another record */
+        }
+#ifndef OPENSSL_NO_SCTP
+    }
+#endif
+
+    /* just read a 0 length packet */
+    if (rr->length == 0)
+        goto again;
+
+    /*
+     * If this record is from the next epoch (either HM or ALERT), and a
+     * handshake is currently in progress, buffer it since it cannot be
+     * processed at this time. However, do not buffer anything while
+     * listening.
+     */
+    if (is_next_epoch) {
+        if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
+            if (dtls1_buffer_record
+                (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
+                return -1;
+            /* Mark receipt of record. */
+            dtls1_record_bitmap_update(s, bitmap);
+        }
+        rr->length = 0;
+        s->packet_length = 0;
+        goto again;
+    }
+
+    if (!dtls1_process_record(s)) {
+        rr->length = 0;
+        s->packet_length = 0;   /* dump this record */
+        goto again;             /* get another record */
+    }
+    dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */
+
+    return (1);
+
+}
+
+/*-
+ * Return up to 'len' payload bytes received in 'type' records.
+ * 'type' is one of the following:
+ *
+ *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
+ *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
+ *   -  0 (during a shutdown, no data has to be returned)
+ *
+ * If we don't have stored data to work from, read a SSL/TLS record first
+ * (possibly multiple records if we still don't have anything to return).
+ *
+ * This function must handle any surprises the peer may have for us, such as
+ * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
+ * a surprise, but handled as if it were), or renegotiation requests.
+ * Also if record payloads contain fragments too small to process, we store
+ * them until there is enough for the respective protocol (the record protocol
+ * may use arbitrary fragmentation and even interleaving):
+ *     Change cipher spec protocol
+ *             just 1 byte needed, no need for keeping anything stored
+ *     Alert protocol
+ *             2 bytes needed (AlertLevel, AlertDescription)
+ *     Handshake protocol
+ *             4 bytes needed (HandshakeType, uint24 length) -- we just have
+ *             to detect unexpected Client Hello and Hello Request messages
+ *             here, anything else is handled by higher layers
+ *     Application data protocol
+ *             none of our business
+ */
+int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
+{
+    int al, i, j, ret;
+    unsigned int n;
+    SSL3_RECORD *rr;
+    void (*cb) (const SSL *ssl, int type2, int val) = NULL;
+
+    if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
+        if (!ssl3_setup_buffers(s))
+            return (-1);
+
+    /* XXX: check what the second '&& type' is about */
+    if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
+         (type != SSL3_RT_HANDSHAKE) && type) ||
+        (peek && (type != SSL3_RT_APPLICATION_DATA))) {
+        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
+        return -1;
+    }
+
+    /*
+     * check whether there's a handshake message (client hello?) waiting
+     */
+    if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
+        return ret;
+
+    /*
+     * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
+     */
+
+#ifndef OPENSSL_NO_SCTP
+    /*
+     * Continue handshake if it had to be interrupted to read app data with
+     * SCTP.
+     */
+    if ((!s->in_handshake && SSL_in_init(s)) ||
+        (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+         (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
+          || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
+         && s->s3->in_read_app_data != 2))
+#else
+    if (!s->in_handshake && SSL_in_init(s))
+#endif
+    {
+        /* type == SSL3_RT_APPLICATION_DATA */
+        i = s->handshake_func(s);
+        if (i < 0)
+            return (i);
+        if (i == 0) {
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
+            return (-1);
+        }
+    }
+
+ start:
+    s->rwstate = SSL_NOTHING;
+
+    /*-
+     * s->s3->rrec.type         - is the type of record
+     * s->s3->rrec.data,    - data
+     * s->s3->rrec.off,     - offset into 'data' for next read
+     * s->s3->rrec.length,  - number of bytes.
+     */
+    rr = &(s->s3->rrec);
+
+    /*
+     * We are not handshaking and have no data yet, so process data buffered
+     * during the last handshake in advance, if any.
+     */
+    if (s->state == SSL_ST_OK && rr->length == 0) {
+        pitem *item;
+        item = pqueue_pop(s->d1->buffered_app_data.q);
+        if (item) {
+#ifndef OPENSSL_NO_SCTP
+            /* Restore bio_dgram_sctp_rcvinfo struct */
+            if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
+                DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
+                BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
+                         sizeof(rdata->recordinfo), &rdata->recordinfo);
+            }
+#endif
+
+            dtls1_copy_record(s, item);
+
+            OPENSSL_free(item->data);
+            pitem_free(item);
+        }
+    }
+
+    /* Check for timeout */
+    if (dtls1_handle_timeout(s) > 0)
+        goto start;
+
+    /* get new packet if necessary */
+    if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
+        ret = dtls1_get_record(s);
+        if (ret <= 0) {
+            ret = dtls1_read_failed(s, ret);
+            /* anything other than a timeout is an error */
+            if (ret <= 0)
+                return (ret);
+            else
+                goto start;
+        }
+    }
+
+    if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
+        rr->length = 0;
+        goto start;
+    }
+
+    /* we now have a packet which can be read and processed */
+
+    if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
+                                   * reset by ssl3_get_finished */
+        && (rr->type != SSL3_RT_HANDSHAKE)) {
+        /*
+         * We now have application data between CCS and Finished. Most likely
+         * the packets were reordered on their way, so buffer the application
+         * data for later processing rather than dropping the connection.
+         */
+        if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
+            0) {
+            SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
+            return -1;
+        }
+        rr->length = 0;
+        goto start;
+    }
+
+    /*
+     * If the other end has shut down, throw anything we read away (even in
+     * 'peek' mode)
+     */
+    if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
+        rr->length = 0;
+        s->rwstate = SSL_NOTHING;
+        return (0);
+    }
+
+    if (type == rr->type) {     /* SSL3_RT_APPLICATION_DATA or
+                                 * SSL3_RT_HANDSHAKE */
+        /*
+         * make sure that we are not getting application data when we are
+         * doing a handshake for the first time
+         */
+        if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
+            (s->enc_read_ctx == NULL)) {
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
+            goto f_err;
+        }
+
+        if (len <= 0)
+            return (len);
+
+        if ((unsigned int)len > rr->length)
+            n = rr->length;
+        else
+            n = (unsigned int)len;
+
+        memcpy(buf, &(rr->data[rr->off]), n);
+        if (!peek) {
+            rr->length -= n;
+            rr->off += n;
+            if (rr->length == 0) {
+                s->rstate = SSL_ST_READ_HEADER;
+                rr->off = 0;
+            }
+        }
+#ifndef OPENSSL_NO_SCTP
+        /*
+         * We were about to renegotiate but had to read belated application
+         * data first, so retry.
+         */
+        if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+            rr->type == SSL3_RT_APPLICATION_DATA &&
+            (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
+             || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
+            s->rwstate = SSL_READING;
+            BIO_clear_retry_flags(SSL_get_rbio(s));
+            BIO_set_retry_read(SSL_get_rbio(s));
+        }
+
+        /*
+         * We might had to delay a close_notify alert because of reordered
+         * app data. If there was an alert and there is no message to read
+         * anymore, finally set shutdown.
+         */
+        if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+            s->d1->shutdown_received
+            && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
+            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
+            return (0);
+        }
+#endif
+        return (n);
+    }
+
+    /*
+     * If we get here, then type != rr->type; if we have a handshake message,
+     * then it was unexpected (Hello Request or Client Hello).
+     */
+
+    /*
+     * In case of record types for which we have 'fragment' storage, fill
+     * that so that we can process the data at a fixed place.
+     */
+    {
+        unsigned int k, dest_maxlen = 0;
+        unsigned char *dest = NULL;
+        unsigned int *dest_len = NULL;
+
+        if (rr->type == SSL3_RT_HANDSHAKE) {
+            dest_maxlen = sizeof s->d1->handshake_fragment;
+            dest = s->d1->handshake_fragment;
+            dest_len = &s->d1->handshake_fragment_len;
+        } else if (rr->type == SSL3_RT_ALERT) {
+            dest_maxlen = sizeof(s->d1->alert_fragment);
+            dest = s->d1->alert_fragment;
+            dest_len = &s->d1->alert_fragment_len;
+        }
+#ifndef OPENSSL_NO_HEARTBEATS
+        else if (rr->type == TLS1_RT_HEARTBEAT) {
+            dtls1_process_heartbeat(s);
+
+            /* Exit and notify application to read again */
+            rr->length = 0;
+            s->rwstate = SSL_READING;
+            BIO_clear_retry_flags(SSL_get_rbio(s));
+            BIO_set_retry_read(SSL_get_rbio(s));
+            return (-1);
+        }
+#endif
+        /* else it's a CCS message, or application data or wrong */
+        else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
+            /*
+             * Application data while renegotiating is allowed. Try again
+             * reading.
+             */
+            if (rr->type == SSL3_RT_APPLICATION_DATA) {
+                BIO *bio;
+                s->s3->in_read_app_data = 2;
+                bio = SSL_get_rbio(s);
+                s->rwstate = SSL_READING;
+                BIO_clear_retry_flags(bio);
+                BIO_set_retry_read(bio);
+                return (-1);
+            }
+
+            /* Not certain if this is the right error handling */
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
+            goto f_err;
+        }
+
+        if (dest_maxlen > 0) {
+            /*
+             * XDTLS: In a pathalogical case, the Client Hello may be
+             * fragmented--don't always expect dest_maxlen bytes
+             */
+            if (rr->length < dest_maxlen) {
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+                /*
+                 * for normal alerts rr->length is 2, while
+                 * dest_maxlen is 7 if we were to handle this
+                 * non-existing alert...
+                 */
+                FIX ME
+#endif
+                 s->rstate = SSL_ST_READ_HEADER;
+                rr->length = 0;
+                goto start;
+            }
+
+            /* now move 'n' bytes: */
+            for (k = 0; k < dest_maxlen; k++) {
+                dest[k] = rr->data[rr->off++];
+                rr->length--;
+            }
+            *dest_len = dest_maxlen;
+        }
+    }
+
+    /*-
+     * s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
+     * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
+     * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
+     */
+
+    /* If we are a client, check for an incoming 'Hello Request': */
+    if ((!s->server) &&
+        (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
+        (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
+        (s->session != NULL) && (s->session->cipher != NULL)) {
+        s->d1->handshake_fragment_len = 0;
+
+        if ((s->d1->handshake_fragment[1] != 0) ||
+            (s->d1->handshake_fragment[2] != 0) ||
+            (s->d1->handshake_fragment[3] != 0)) {
+            al = SSL_AD_DECODE_ERROR;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
+            goto f_err;
+        }
+
+        /*
+         * no need to check sequence number on HELLO REQUEST messages
+         */
+
+        if (s->msg_callback)
+            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+                            s->d1->handshake_fragment, 4, s,
+                            s->msg_callback_arg);
+
+        if (SSL_is_init_finished(s) &&
+            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
+            !s->s3->renegotiate) {
+            s->d1->handshake_read_seq++;
+            s->new_session = 1;
+            ssl3_renegotiate(s);
+            if (ssl3_renegotiate_check(s)) {
+                i = s->handshake_func(s);
+                if (i < 0)
+                    return (i);
+                if (i == 0) {
+                    SSLerr(SSL_F_DTLS1_READ_BYTES,
+                           SSL_R_SSL_HANDSHAKE_FAILURE);
+                    return (-1);
+                }
+
+                if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
+                    if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
+                        BIO *bio;
+                        /*
+                         * In the case where we try to read application data,
+                         * but we trigger an SSL handshake, we return -1 with
+                         * the retry option set.  Otherwise renegotiation may
+                         * cause nasty problems in the blocking world
+                         */
+                        s->rwstate = SSL_READING;
+                        bio = SSL_get_rbio(s);
+                        BIO_clear_retry_flags(bio);
+                        BIO_set_retry_read(bio);
+                        return (-1);
+                    }
+                }
+            }
+        }
+        /*
+         * we either finished a handshake or ignored the request, now try
+         * again to obtain the (application) data we were asked for
+         */
+        goto start;
+    }
+
+    if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
+        int alert_level = s->d1->alert_fragment[0];
+        int alert_descr = s->d1->alert_fragment[1];
+
+        s->d1->alert_fragment_len = 0;
+
+        if (s->msg_callback)
+            s->msg_callback(0, s->version, SSL3_RT_ALERT,
+                            s->d1->alert_fragment, 2, s, s->msg_callback_arg);
+
+        if (s->info_callback != NULL)
+            cb = s->info_callback;
+        else if (s->ctx->info_callback != NULL)
+            cb = s->ctx->info_callback;
+
+        if (cb != NULL) {
+            j = (alert_level << 8) | alert_descr;
+            cb(s, SSL_CB_READ_ALERT, j);
+        }
+
+        if (alert_level == SSL3_AL_WARNING) {
+            s->s3->warn_alert = alert_descr;
+            if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
+#ifndef OPENSSL_NO_SCTP
+                /*
+                 * With SCTP and streams the socket may deliver app data
+                 * after a close_notify alert. We have to check this first so
+                 * that nothing gets discarded.
+                 */
+                if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+                    BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
+                    s->d1->shutdown_received = 1;
+                    s->rwstate = SSL_READING;
+                    BIO_clear_retry_flags(SSL_get_rbio(s));
+                    BIO_set_retry_read(SSL_get_rbio(s));
+                    return -1;
+                }
+#endif
+                s->shutdown |= SSL_RECEIVED_SHUTDOWN;
+                return (0);
+            }
+#if 0
+            /* XXX: this is a possible improvement in the future */
+            /* now check if it's a missing record */
+            if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
+                unsigned short seq;
+                unsigned int frag_off;
+                unsigned char *p = &(s->d1->alert_fragment[2]);
+
+                n2s(p, seq);
+                n2l3(p, frag_off);
+
+                dtls1_retransmit_message(s,
+                                         dtls1_get_queue_priority
+                                         (frag->msg_header.seq, 0), frag_off,
+                                         &found);
+                if (!found && SSL_in_init(s)) {
+                    /*
+                     * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
+                     */
+                    /*
+                     * requested a message not yet sent, send an alert
+                     * ourselves
+                     */
+                    ssl3_send_alert(s, SSL3_AL_WARNING,
+                                    DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
+                }
+            }
+#endif
+        } else if (alert_level == SSL3_AL_FATAL) {
+            char tmp[16];
+
+            s->rwstate = SSL_NOTHING;
+            s->s3->fatal_alert = alert_descr;
+            SSLerr(SSL_F_DTLS1_READ_BYTES,
+                   SSL_AD_REASON_OFFSET + alert_descr);
+            BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
+            ERR_add_error_data(2, "SSL alert number ", tmp);
+            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
+            SSL_CTX_remove_session(s->ctx, s->session);
+            return (0);
+        } else {
+            al = SSL_AD_ILLEGAL_PARAMETER;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
+            goto f_err;
+        }
+
+        goto start;
+    }
+
+    if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
+                                            * shutdown */
+        s->rwstate = SSL_NOTHING;
+        rr->length = 0;
+        return (0);
+    }
+
+    if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
+        struct ccs_header_st ccs_hdr;
+        unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
+
+        dtls1_get_ccs_header(rr->data, &ccs_hdr);
+
+        if (s->version == DTLS1_BAD_VER)
+            ccs_hdr_len = 3;
+
+        /*
+         * 'Change Cipher Spec' is just a single byte, so we know exactly
+         * what the record payload has to look like
+         */
+        /* XDTLS: check that epoch is consistent */
+        if ((rr->length != ccs_hdr_len) ||
+            (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
+            i = SSL_AD_ILLEGAL_PARAMETER;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
+            goto err;
+        }
+
+        rr->length = 0;
+
+        if (s->msg_callback)
+            s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
+                            rr->data, 1, s, s->msg_callback_arg);
+
+        /*
+         * We can't process a CCS now, because previous handshake messages
+         * are still missing, so just drop it.
+         */
+        if (!s->d1->change_cipher_spec_ok) {
+            goto start;
+        }
+
+        s->d1->change_cipher_spec_ok = 0;
+
+        s->s3->change_cipher_spec = 1;
+        if (!ssl3_do_change_cipher_spec(s))
+            goto err;
+
+        /* do this whenever CCS is processed */
+        dtls1_reset_seq_numbers(s, SSL3_CC_READ);
+
+        if (s->version == DTLS1_BAD_VER)
+            s->d1->handshake_read_seq++;
+
+#ifndef OPENSSL_NO_SCTP
+        /*
+         * Remember that a CCS has been received, so that an old key of
+         * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
+         * SCTP is used
+         */
+        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
+#endif
+
+        goto start;
+    }
+
+    /*
+     * Unexpected handshake message (Client Hello, or protocol violation)
+     */
+    if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
+        !s->in_handshake) {
+        struct hm_header_st msg_hdr;
+
+        /* this may just be a stale retransmit */
+        dtls1_get_message_header(rr->data, &msg_hdr);
+        if (rr->epoch != s->d1->r_epoch) {
+            rr->length = 0;
+            goto start;
+        }
+
+        /*
+         * If we are server, we may have a repeated FINISHED of the client
+         * here, then retransmit our CCS and FINISHED.
+         */
+        if (msg_hdr.type == SSL3_MT_FINISHED) {
+            if (dtls1_check_timeout_num(s) < 0)
+                return -1;
+
+            dtls1_retransmit_buffered_messages(s);
+            rr->length = 0;
+            goto start;
+        }
+
+        if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
+            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
+#if 0                           /* worked only because C operator preferences
+                                 * are not as expected (and because this is
+                                 * not really needed for clients except for
+                                 * detecting protocol violations): */
+            s->state = SSL_ST_BEFORE | (s->server)
+                ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
+#else
+            s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
+#endif
+            s->renegotiate = 1;
+            s->new_session = 1;
+        }
+        i = s->handshake_func(s);
+        if (i < 0)
+            return (i);
+        if (i == 0) {
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
+            return (-1);
+        }
+
+        if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
+            if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
+                BIO *bio;
+                /*
+                 * In the case where we try to read application data, but we
+                 * trigger an SSL handshake, we return -1 with the retry
+                 * option set.  Otherwise renegotiation may cause nasty
+                 * problems in the blocking world
+                 */
+                s->rwstate = SSL_READING;
+                bio = SSL_get_rbio(s);
+                BIO_clear_retry_flags(bio);
+                BIO_set_retry_read(bio);
+                return (-1);
+            }
+        }
+        goto start;
+    }
+
+    switch (rr->type) {
+    default:
+#ifndef OPENSSL_NO_TLS
+        /* TLS just ignores unknown message types */
+        if (s->version == TLS1_VERSION) {
+            rr->length = 0;
+            goto start;
+        }
+#endif
+        al = SSL_AD_UNEXPECTED_MESSAGE;
+        SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
+        goto f_err;
+    case SSL3_RT_CHANGE_CIPHER_SPEC:
+    case SSL3_RT_ALERT:
+    case SSL3_RT_HANDSHAKE:
+        /*
+         * we already handled all of these, with the possible exception of
+         * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
+         * happen when type != rr->type
+         */
+        al = SSL_AD_UNEXPECTED_MESSAGE;
+        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
+        goto f_err;
+    case SSL3_RT_APPLICATION_DATA:
+        /*
+         * At this point, we were expecting handshake data, but have
+         * application data.  If the library was running inside ssl3_read()
+         * (i.e. in_read_app_data is set) and it makes sense to read
+         * application data at this point (session renegotiation not yet
+         * started), we will indulge it.
+         */
+        if (s->s3->in_read_app_data &&
+            (s->s3->total_renegotiations != 0) &&
+            (((s->state & SSL_ST_CONNECT) &&
+              (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
+              (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
+             ) || ((s->state & SSL_ST_ACCEPT) &&
+                   (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
+                   (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
+             )
+            )) {
+            s->s3->in_read_app_data = 2;
+            return (-1);
+        } else {
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
+            goto f_err;
+        }
+    }
+    /* not reached */
+
+ f_err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+ err:
+    return (-1);
+}
+
+int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
+{
+    int i;
+
+#ifndef OPENSSL_NO_SCTP
+    /*
+     * Check if we have to continue an interrupted handshake for reading
+     * belated app data with SCTP.
+     */
+    if ((SSL_in_init(s) && !s->in_handshake) ||
+        (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+         (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
+          || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
+#else
+    if (SSL_in_init(s) && !s->in_handshake)
+#endif
+    {
+        i = s->handshake_func(s);
+        if (i < 0)
+            return (i);
+        if (i == 0) {
+            SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
+                   SSL_R_SSL_HANDSHAKE_FAILURE);
+            return -1;
+        }
+    }
+
+    if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
+        SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
+        return -1;
+    }
+
+    i = dtls1_write_bytes(s, type, buf_, len);
+    return i;
+}
+
+        /*
+         * this only happens when a client hello is received and a handshake
+         * is started.
+         */
+static int
+have_handshake_fragment(SSL *s, int type, unsigned char *buf,
+                        int len, int peek)
+{
+
+    if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
+        /* (partially) satisfy request from storage */
+    {
+        unsigned char *src = s->d1->handshake_fragment;
+        unsigned char *dst = buf;
+        unsigned int k, n;
+
+        /* peek == 0 */
+        n = 0;
+        while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
+            *dst++ = *src++;
+            len--;
+            s->d1->handshake_fragment_len--;
+            n++;
+        }
+        /* move any remaining fragment bytes: */
+        for (k = 0; k < s->d1->handshake_fragment_len; k++)
+            s->d1->handshake_fragment[k] = *src++;
+        return n;
+    }
+
+    return 0;
+}
+
+/*
+ * Call this to write data in records of type 'type' It will return <= 0 if
+ * not all data has been sent or non-blocking IO.
+ */
+int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
+{
+    int i;
+
+    OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
+    s->rwstate = SSL_NOTHING;
+    i = do_dtls1_write(s, type, buf, len, 0);
+    return i;
+}
+
+int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
+                   unsigned int len, int create_empty_fragment)
+{
+    unsigned char *p, *pseq;
+    int i, mac_size, clear = 0;
+    int prefix_len = 0;
+    int eivlen;
+    SSL3_RECORD *wr;
+    SSL3_BUFFER *wb;
+    SSL_SESSION *sess;
+
+    /*
+     * first check if there is a SSL3_BUFFER still being written out.  This
+     * will happen with non blocking IO
+     */
+    if (s->s3->wbuf.left != 0) {
+        OPENSSL_assert(0);      /* XDTLS: want to see if we ever get here */
+        return (ssl3_write_pending(s, type, buf, len));
+    }
+
+    /* If we have an alert to send, lets send it */
+    if (s->s3->alert_dispatch) {
+        i = s->method->ssl_dispatch_alert(s);
+        if (i <= 0)
+            return (i);
+        /* if it went, fall through and send more stuff */
+    }
+
+    if (len == 0 && !create_empty_fragment)
+        return 0;
+
+    wr = &(s->s3->wrec);
+    wb = &(s->s3->wbuf);
+    sess = s->session;
+
+    if ((sess == NULL) ||
+        (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
+        clear = 1;
+
+    if (clear)
+        mac_size = 0;
+    else {
+        mac_size = EVP_MD_CTX_size(s->write_hash);
+        if (mac_size < 0)
+            goto err;
+    }
+
+    /* DTLS implements explicit IV, so no need for empty fragments */
+#if 0
+    /*
+     * 'create_empty_fragment' is true only when this function calls itself
+     */
+    if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
+        && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
+    {
+        /*
+         * countermeasure against known-IV weakness in CBC ciphersuites (see
+         * http://www.openssl.org/~bodo/tls-cbc.txt)
+         */
+
+        if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) {
+            /*
+             * recursive function call with 'create_empty_fragment' set; this
+             * prepares and buffers the data for an empty fragment (these
+             * 'prefix_len' bytes are sent out later together with the actual
+             * payload)
+             */
+            prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
+            if (prefix_len <= 0)
+                goto err;
+
+            if (s->s3->wbuf.len <
+                (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) {
+                /* insufficient space */
+                SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
+                goto err;
+            }
+        }
+
+        s->s3->empty_fragment_done = 1;
+    }
+#endif
+    p = wb->buf + prefix_len;
+
+    /* write the header */
+
+    *(p++) = type & 0xff;
+    wr->type = type;
+    /*
+     * 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.
+     */
+    if (s->method->version == DTLS_ANY_VERSION) {
+        *(p++) = DTLS1_VERSION >> 8;
+        *(p++) = DTLS1_VERSION & 0xff;
+    } else {
+        *(p++) = s->version >> 8;
+        *(p++) = s->version & 0xff;
+    }
+
+    /* field where we are to write out packet epoch, seq num and len */
+    pseq = p;
+    p += 10;
+
+    /* Explicit IV length, block ciphers appropriate version flag */
+    if (s->enc_write_ctx) {
+        int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
+        if (mode == EVP_CIPH_CBC_MODE) {
+            eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
+            if (eivlen <= 1)
+                eivlen = 0;
+        }
+        /* Need explicit part of IV for GCM mode */
+        else if (mode == EVP_CIPH_GCM_MODE)
+            eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
+        else
+            eivlen = 0;
+    } else
+        eivlen = 0;
+
+    /* lets setup the record stuff. */
+    wr->data = p + eivlen;      /* make room for IV in case of CBC */
+    wr->length = (int)len;
+    wr->input = (unsigned char *)buf;
+
+    /*
+     * we now 'read' from wr->input, wr->length bytes into wr->data
+     */
+
+    /* first we compress */
+    if (s->compress != NULL) {
+        if (!ssl3_do_compress(s)) {
+            SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
+            goto err;
+        }
+    } else {
+        memcpy(wr->data, wr->input, wr->length);
+        wr->input = wr->data;
+    }
+
+    /*
+     * we should still have the output to wr->data and the input from
+     * wr->input.  Length should be wr->length. wr->data still points in the
+     * wb->buf
+     */
+
+    if (mac_size != 0) {
+        if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
+            goto err;
+        wr->length += mac_size;
+    }
+
+    /* this is true regardless of mac size */
+    wr->input = p;
+    wr->data = p;
+
+    if (eivlen)
+        wr->length += eivlen;
+
+    if (s->method->ssl3_enc->enc(s, 1) < 1)
+        goto err;
+
+    /* record length after mac and block padding */
+    /*
+     * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
+     * SSL_in_init(s)))
+     */
+
+    /* there's only one epoch between handshake and app data */
+
+    s2n(s->d1->w_epoch, pseq);
+
+    /* XDTLS: ?? */
+    /*
+     * else s2n(s->d1->handshake_epoch, pseq);
+     */
+
+    memcpy(pseq, &(s->s3->write_sequence[2]), 6);
+    pseq += 6;
+    s2n(wr->length, pseq);
+
+    if (s->msg_callback)
+        s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
+                        DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
+
+    /*
+     * we should now have wr->data pointing to the encrypted data, which is
+     * wr->length long
+     */
+    wr->type = type;            /* not needed but helps for debugging */
+    wr->length += DTLS1_RT_HEADER_LENGTH;
+
+#if 0                           /* this is now done at the message layer */
+    /* buffer the record, making it easy to handle retransmits */
+    if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
+        dtls1_buffer_record(s, wr->data, wr->length,
+                            *((PQ_64BIT *) & (s->s3->write_sequence[0])));
+#endif
+
+    ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
+
+    if (create_empty_fragment) {
+        /*
+         * we are in a recursive call; just return the length, don't write
+         * out anything here
+         */
+        return wr->length;
+    }
+
+    /* now let's set up wb */
+    wb->left = prefix_len + wr->length;
+    wb->offset = 0;
+
+    /*
+     * memorize arguments so that ssl3_write_pending can detect bad write
+     * retries later
+     */
+    s->s3->wpend_tot = len;
+    s->s3->wpend_buf = buf;
+    s->s3->wpend_type = type;
+    s->s3->wpend_ret = len;
+
+    /* we now just need to write the buffer */
+    return ssl3_write_pending(s, type, buf, len);
+ err:
+    return -1;
+}
+
+static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
+{
+    int cmp;
+    unsigned int shift;
+    const unsigned char *seq = s->s3->read_sequence;
+
+    cmp = satsub64be(seq, bitmap->max_seq_num);
+    if (cmp > 0) {
+        memcpy(s->s3->rrec.seq_num, seq, 8);
+        return 1;               /* this record in new */
+    }
+    shift = -cmp;
+    if (shift >= sizeof(bitmap->map) * 8)
+        return 0;               /* stale, outside the window */
+    else if (bitmap->map & (1UL << shift))
+        return 0;               /* record previously received */
+
+    memcpy(s->s3->rrec.seq_num, seq, 8);
+    return 1;
+}
+
+static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
+{
+    int cmp;
+    unsigned int shift;
+    const unsigned char *seq = s->s3->read_sequence;
+
+    cmp = satsub64be(seq, bitmap->max_seq_num);
+    if (cmp > 0) {
+        shift = cmp;
+        if (shift < sizeof(bitmap->map) * 8)
+            bitmap->map <<= shift, bitmap->map |= 1UL;
+        else
+            bitmap->map = 1UL;
+        memcpy(bitmap->max_seq_num, seq, 8);
+    } else {
+        shift = -cmp;
+        if (shift < sizeof(bitmap->map) * 8)
+            bitmap->map |= 1UL << shift;
+    }
+}
+
+int dtls1_dispatch_alert(SSL *s)
+{
+    int i, j;
+    void (*cb) (const SSL *ssl, int type, int val) = NULL;
+    unsigned char buf[DTLS1_AL_HEADER_LENGTH];
+    unsigned char *ptr = &buf[0];
+
+    s->s3->alert_dispatch = 0;
+
+    memset(buf, 0x00, sizeof(buf));
+    *ptr++ = s->s3->send_alert[0];
+    *ptr++ = s->s3->send_alert[1];
+
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+    if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
+        s2n(s->d1->handshake_read_seq, ptr);
+# if 0
+        if (s->d1->r_msg_hdr.frag_off == 0)
+            /*
+             * waiting for a new msg
+             */
+            else
+            s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
+# endif
+
+# if 0
+        fprintf(stderr,
+                "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",
+                s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq);
+# endif
+        l2n3(s->d1->r_msg_hdr.frag_off, ptr);
+    }
+#endif
+
+    i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
+    if (i <= 0) {
+        s->s3->alert_dispatch = 1;
+        /* fprintf( stderr, "not done with alert\n" ); */
+    } else {
+        if (s->s3->send_alert[0] == SSL3_AL_FATAL
+#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+            || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
+#endif
+            )
+            (void)BIO_flush(s->wbio);
+
+        if (s->msg_callback)
+            s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
+                            2, s, s->msg_callback_arg);
+
+        if (s->info_callback != NULL)
+            cb = s->info_callback;
+        else if (s->ctx->info_callback != NULL)
+            cb = s->ctx->info_callback;
+
+        if (cb != NULL) {
+            j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
+            cb(s, SSL_CB_WRITE_ALERT, j);
+        }
+    }
+    return (i);
+}
+
+static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
+                                      unsigned int *is_next_epoch)
+{
+
+    *is_next_epoch = 0;
+
+    /* In current epoch, accept HM, CCS, DATA, & ALERT */
+    if (rr->epoch == s->d1->r_epoch)
+        return &s->d1->bitmap;
+
+    /* Only HM and ALERT messages can be from the next epoch */
+    else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
+             (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
+        *is_next_epoch = 1;
+        return &s->d1->next_bitmap;
+    }
+
+    return NULL;
+}
+
+#if 0
+static int
+dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
+                             unsigned short *priority, unsigned long *offset)
+{
+
+    /* alerts are passed up immediately */
+    if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT)
+        return 0;
+
+    /*
+     * Only need to buffer if a handshake is underway. (this implies that
+     * Hello Request and Client Hello are passed up immediately)
+     */
+    if (SSL_in_init(s)) {
+        unsigned char *data = rr->data;
+        /* need to extract the HM/CCS sequence number here */
+        if (rr->type == SSL3_RT_HANDSHAKE ||
+            rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
+            unsigned short seq_num;
+            struct hm_header_st msg_hdr;
+            struct ccs_header_st ccs_hdr;
+
+            if (rr->type == SSL3_RT_HANDSHAKE) {
+                dtls1_get_message_header(data, &msg_hdr);
+                seq_num = msg_hdr.seq;
+                *offset = msg_hdr.frag_off;
+            } else {
+                dtls1_get_ccs_header(data, &ccs_hdr);
+                seq_num = ccs_hdr.seq;
+                *offset = 0;
+            }
+
+            /*
+             * this is either a record we're waiting for, or a retransmit of
+             * something we happened to previously receive (higher layers
+             * will drop the repeat silently
+             */
+            if (seq_num < s->d1->handshake_read_seq)
+                return 0;
+            if (rr->type == SSL3_RT_HANDSHAKE &&
+                seq_num == s->d1->handshake_read_seq &&
+                msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
+                return 0;
+            else if (seq_num == s->d1->handshake_read_seq &&
+                     (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
+                      msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
+                return 0;
+            else {
+                *priority = seq_num;
+                return 1;
+            }
+        } else                  /* unknown record type */
+            return 0;
+    }
+
+    return 0;
+}
+#endif
+
+void dtls1_reset_seq_numbers(SSL *s, int rw)
+{
+    unsigned char *seq;
+    unsigned int seq_bytes = sizeof(s->s3->read_sequence);
+
+    if (rw & SSL3_CC_READ) {
+        seq = s->s3->read_sequence;
+        s->d1->r_epoch++;
+        memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
+        memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
+    } else {
+        seq = s->s3->write_sequence;
+        memcpy(s->d1->last_write_sequence, seq,
+               sizeof(s->s3->write_sequence));
+        s->d1->w_epoch++;
+    }
+
+    memset(seq, 0x00, seq_bytes);
+}