Import openssl from FreeBSD.

1 files changed, 1587 insertions, 0 deletions

diff --git a/freebsd/crypto/openssl/ssl/d1_both.c b/freebsd/crypto/openssl/ssl/d1_both.c
new file mode 100644
index 00000000..caa5feaa
--- /dev/null
+++ b/freebsd/crypto/openssl/ssl/d1_both.c
@@ -0,0 +1,1587 @@
+#include <machine/rtems-bsd-user-space.h>
+
+/* ssl/d1_both.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 <limits.h>
+#include <string.h>
+#include <stdio.h>
+#include "ssl_locl.h"
+#include <openssl/buffer.h>
+#include <openssl/rand.h>
+#include <openssl/objects.h>
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+
+#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
+
+#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
+                        if ((end) - (start) <= 8) { \
+                                long ii; \
+                                for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
+                        } else { \
+                                long ii; \
+                                bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
+                                for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
+                                bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
+                        } }
+
+#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
+                        long ii; \
+                        OPENSSL_assert((msg_len) > 0); \
+                        is_complete = 1; \
+                        if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
+                        if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
+                                if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
+
+#if 0
+# define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
+                        long ii; \
+                        printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
+                        printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
+                        printf("\n"); }
+#endif
+
+static unsigned char bitmask_start_values[] =
+    { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
+static unsigned char bitmask_end_values[] =
+    { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
+
+/* XDTLS:  figure out the right values */
+static const unsigned int g_probable_mtu[] = { 1500, 512, 256 };
+
+static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
+                                     unsigned long frag_len);
+static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
+static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
+                                         unsigned long len,
+                                         unsigned short seq_num,
+                                         unsigned long frag_off,
+                                         unsigned long frag_len);
+static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max,
+                                       int *ok);
+
+static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
+                                          int reassembly)
+{
+    hm_fragment *frag = NULL;
+    unsigned char *buf = NULL;
+    unsigned char *bitmask = NULL;
+
+    frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
+    if (frag == NULL)
+        return NULL;
+
+    if (frag_len) {
+        buf = (unsigned char *)OPENSSL_malloc(frag_len);
+        if (buf == NULL) {
+            OPENSSL_free(frag);
+            return NULL;
+        }
+    }
+
+    /* zero length fragment gets zero frag->fragment */
+    frag->fragment = buf;
+
+    /* Initialize reassembly bitmask if necessary */
+    if (reassembly) {
+        bitmask =
+            (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
+        if (bitmask == NULL) {
+            if (buf != NULL)
+                OPENSSL_free(buf);
+            OPENSSL_free(frag);
+            return NULL;
+        }
+        memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
+    }
+
+    frag->reassembly = bitmask;
+
+    return frag;
+}
+
+void dtls1_hm_fragment_free(hm_fragment *frag)
+{
+
+    if (frag->msg_header.is_ccs) {
+        EVP_CIPHER_CTX_free(frag->msg_header.
+                            saved_retransmit_state.enc_write_ctx);
+        EVP_MD_CTX_destroy(frag->msg_header.
+                           saved_retransmit_state.write_hash);
+    }
+    if (frag->fragment)
+        OPENSSL_free(frag->fragment);
+    if (frag->reassembly)
+        OPENSSL_free(frag->reassembly);
+    OPENSSL_free(frag);
+}
+
+static int dtls1_query_mtu(SSL *s)
+{
+    if (s->d1->link_mtu) {
+        s->d1->mtu =
+            s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
+        s->d1->link_mtu = 0;
+    }
+
+    /* AHA!  Figure out the MTU, and stick to the right size */
+    if (s->d1->mtu < dtls1_min_mtu(s)) {
+        if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
+            s->d1->mtu =
+                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
+
+            /*
+             * I've seen the kernel return bogus numbers when it doesn't know
+             * (initial write), so just make sure we have a reasonable number
+             */
+            if (s->d1->mtu < dtls1_min_mtu(s)) {
+                /* Set to min mtu */
+                s->d1->mtu = dtls1_min_mtu(s);
+                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
+                         s->d1->mtu, NULL);
+            }
+        } else
+            return 0;
+    }
+    return 1;
+}
+
+/*
+ * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
+ * SSL3_RT_CHANGE_CIPHER_SPEC)
+ */
+int dtls1_do_write(SSL *s, int type)
+{
+    int ret;
+    unsigned int curr_mtu;
+    int retry = 1;
+    unsigned int len, frag_off, mac_size, blocksize, used_len;
+
+    if (!dtls1_query_mtu(s))
+        return -1;
+
+    OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something
+                                                     * reasonable now */
+
+    if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
+        OPENSSL_assert(s->init_num ==
+                       (int)s->d1->w_msg_hdr.msg_len +
+                       DTLS1_HM_HEADER_LENGTH);
+
+    if (s->write_hash) {
+        if (s->enc_write_ctx
+            && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
+            mac_size = 0;
+        else
+            mac_size = EVP_MD_CTX_size(s->write_hash);
+    } else
+        mac_size = 0;
+
+    if (s->enc_write_ctx &&
+        (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
+        blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
+    else
+        blocksize = 0;
+
+    frag_off = 0;
+    s->rwstate = SSL_NOTHING;
+
+    /* s->init_num shouldn't ever be < 0...but just in case */
+    while (s->init_num > 0) {
+        if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
+            /* We must be writing a fragment other than the first one */
+
+            if (frag_off > 0) {
+                /* This is the first attempt at writing out this fragment */
+
+                if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
+                    /*
+                     * Each fragment that was already sent must at least have
+                     * contained the message header plus one other byte.
+                     * Therefore |init_off| must have progressed by at least
+                     * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
+                     * wrong.
+                     */
+                    return -1;
+                }
+
+                /*
+                 * Adjust |init_off| and |init_num| to allow room for a new
+                 * message header for this fragment.
+                 */
+                s->init_off -= DTLS1_HM_HEADER_LENGTH;
+                s->init_num += DTLS1_HM_HEADER_LENGTH;
+            } else {
+                /*
+                 * We must have been called again after a retry so use the
+                 * fragment offset from our last attempt. We do not need
+                 * to adjust |init_off| and |init_num| as above, because
+                 * that should already have been done before the retry.
+                 */
+                frag_off = s->d1->w_msg_hdr.frag_off;
+            }
+        }
+
+        used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
+            + mac_size + blocksize;
+        if (s->d1->mtu > used_len)
+            curr_mtu = s->d1->mtu - used_len;
+        else
+            curr_mtu = 0;
+
+        if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
+            /*
+             * grr.. we could get an error if MTU picked was wrong
+             */
+            ret = BIO_flush(SSL_get_wbio(s));
+            if (ret <= 0) {
+                s->rwstate = SSL_WRITING;
+                return ret;
+            }
+            used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
+            if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
+                curr_mtu = s->d1->mtu - used_len;
+            } else {
+                /* Shouldn't happen */
+                return -1;
+            }
+        }
+
+        /*
+         * We just checked that s->init_num > 0 so this cast should be safe
+         */
+        if (((unsigned int)s->init_num) > curr_mtu)
+            len = curr_mtu;
+        else
+            len = s->init_num;
+
+        /* Shouldn't ever happen */
+        if (len > INT_MAX)
+            len = INT_MAX;
+
+        /*
+         * XDTLS: this function is too long.  split out the CCS part
+         */
+        if (type == SSL3_RT_HANDSHAKE) {
+            if (len < DTLS1_HM_HEADER_LENGTH) {
+                /*
+                 * len is so small that we really can't do anything sensible
+                 * so fail
+                 */
+                return -1;
+            }
+            dtls1_fix_message_header(s, frag_off,
+                                     len - DTLS1_HM_HEADER_LENGTH);
+
+            dtls1_write_message_header(s,
+                                       (unsigned char *)&s->init_buf->
+                                       data[s->init_off]);
+        }
+
+        ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
+                                len);
+        if (ret < 0) {
+            /*
+             * might need to update MTU here, but we don't know which
+             * previous packet caused the failure -- so can't really
+             * retransmit anything.  continue as if everything is fine and
+             * wait for an alert to handle the retransmit
+             */
+            if (retry && BIO_ctrl(SSL_get_wbio(s),
+                                  BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
+                if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
+                    if (!dtls1_query_mtu(s))
+                        return -1;
+                    /* Have one more go */
+                    retry = 0;
+                } else
+                    return -1;
+            } else {
+                return (-1);
+            }
+        } else {
+
+            /*
+             * bad if this assert fails, only part of the handshake message
+             * got sent.  but why would this happen?
+             */
+            OPENSSL_assert(len == (unsigned int)ret);
+
+            if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
+                /*
+                 * should not be done for 'Hello Request's, but in that case
+                 * we'll ignore the result anyway
+                 */
+                unsigned char *p =
+                    (unsigned char *)&s->init_buf->data[s->init_off];
+                const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+                int xlen;
+
+                if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
+                    /*
+                     * reconstruct message header is if it is being sent in
+                     * single fragment
+                     */
+                    *p++ = msg_hdr->type;
+                    l2n3(msg_hdr->msg_len, p);
+                    s2n(msg_hdr->seq, p);
+                    l2n3(0, p);
+                    l2n3(msg_hdr->msg_len, p);
+                    p -= DTLS1_HM_HEADER_LENGTH;
+                    xlen = ret;
+                } else {
+                    p += DTLS1_HM_HEADER_LENGTH;
+                    xlen = ret - DTLS1_HM_HEADER_LENGTH;
+                }
+
+                ssl3_finish_mac(s, p, xlen);
+            }
+
+            if (ret == s->init_num) {
+                if (s->msg_callback)
+                    s->msg_callback(1, s->version, type, s->init_buf->data,
+                                    (size_t)(s->init_off + s->init_num), s,
+                                    s->msg_callback_arg);
+
+                s->init_off = 0; /* done writing this message */
+                s->init_num = 0;
+
+                return (1);
+            }
+            s->init_off += ret;
+            s->init_num -= ret;
+            ret -= DTLS1_HM_HEADER_LENGTH;
+            frag_off += ret;
+
+            /*
+             * We save the fragment offset for the next fragment so we have it
+             * available in case of an IO retry. We don't know the length of the
+             * next fragment yet so just set that to 0 for now. It will be
+             * updated again later.
+             */
+            dtls1_fix_message_header(s, frag_off, 0);
+        }
+    }
+    return (0);
+}
+
+/*
+ * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
+ * acceptable body length 'max'. Read an entire handshake message.  Handshake
+ * messages arrive in fragments.
+ */
+long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
+{
+    int i, al;
+    struct hm_header_st *msg_hdr;
+    unsigned char *p;
+    unsigned long msg_len;
+
+    /*
+     * s3->tmp is used to store messages that are unexpected, caused by the
+     * absence of an optional handshake message
+     */
+    if (s->s3->tmp.reuse_message) {
+        s->s3->tmp.reuse_message = 0;
+        if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
+            goto f_err;
+        }
+        *ok = 1;
+        s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+        s->init_num = (int)s->s3->tmp.message_size;
+        return s->init_num;
+    }
+
+    msg_hdr = &s->d1->r_msg_hdr;
+    memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
+
+ again:
+    i = dtls1_get_message_fragment(s, st1, stn, max, ok);
+    if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) {
+        /* bad fragment received */
+        goto again;
+    } else if (i <= 0 && !*ok) {
+        return i;
+    }
+
+    if (mt >= 0 && s->s3->tmp.message_type != mt) {
+        al = SSL_AD_UNEXPECTED_MESSAGE;
+        SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
+        goto f_err;
+    }
+
+    p = (unsigned char *)s->init_buf->data;
+    msg_len = msg_hdr->msg_len;
+
+    /* reconstruct message header */
+    *(p++) = msg_hdr->type;
+    l2n3(msg_len, p);
+    s2n(msg_hdr->seq, p);
+    l2n3(0, p);
+    l2n3(msg_len, p);
+    if (s->version != DTLS1_BAD_VER) {
+        p -= DTLS1_HM_HEADER_LENGTH;
+        msg_len += DTLS1_HM_HEADER_LENGTH;
+    }
+
+    ssl3_finish_mac(s, p, msg_len);
+    if (s->msg_callback)
+        s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+                        p, msg_len, s, s->msg_callback_arg);
+
+    memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
+
+    /* Don't change sequence numbers while listening */
+    if (!s->d1->listen)
+        s->d1->handshake_read_seq++;
+
+    s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+    return s->init_num;
+
+ f_err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+    *ok = 0;
+    return -1;
+}
+
+static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
+                                     int max)
+{
+    size_t frag_off, frag_len, msg_len;
+
+    msg_len = msg_hdr->msg_len;
+    frag_off = msg_hdr->frag_off;
+    frag_len = msg_hdr->frag_len;
+
+    /* sanity checking */
+    if ((frag_off + frag_len) > msg_len) {
+        SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
+        return SSL_AD_ILLEGAL_PARAMETER;
+    }
+
+    if ((frag_off + frag_len) > (unsigned long)max) {
+        SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
+        return SSL_AD_ILLEGAL_PARAMETER;
+    }
+
+    if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
+        /*
+         * msg_len is limited to 2^24, but is effectively checked against max
+         * above
+         *
+         * Make buffer slightly larger than message length as a precaution
+         * against small OOB reads e.g. CVE-2016-6306
+         */
+        if (!BUF_MEM_grow_clean
+            (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) {
+            SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
+            return SSL_AD_INTERNAL_ERROR;
+        }
+
+        s->s3->tmp.message_size = msg_len;
+        s->d1->r_msg_hdr.msg_len = msg_len;
+        s->s3->tmp.message_type = msg_hdr->type;
+        s->d1->r_msg_hdr.type = msg_hdr->type;
+        s->d1->r_msg_hdr.seq = msg_hdr->seq;
+    } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
+        /*
+         * They must be playing with us! BTW, failure to enforce upper limit
+         * would open possibility for buffer overrun.
+         */
+        SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
+        return SSL_AD_ILLEGAL_PARAMETER;
+    }
+
+    return 0;                   /* no error */
+}
+
+static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
+{
+    /*-
+     * (0) check whether the desired fragment is available
+     * if so:
+     * (1) copy over the fragment to s->init_buf->data[]
+     * (2) update s->init_num
+     */
+    pitem *item;
+    hm_fragment *frag;
+    int al;
+
+    *ok = 0;
+    do {
+        item = pqueue_peek(s->d1->buffered_messages);
+        if (item == NULL)
+            return 0;
+
+        frag = (hm_fragment *)item->data;
+
+        if (frag->msg_header.seq < s->d1->handshake_read_seq) {
+            /* This is a stale message that has been buffered so clear it */
+            pqueue_pop(s->d1->buffered_messages);
+            dtls1_hm_fragment_free(frag);
+            pitem_free(item);
+            item = NULL;
+            frag = NULL;
+        }
+    } while (item == NULL);
+
+
+    /* Don't return if reassembly still in progress */
+    if (frag->reassembly != NULL)
+        return 0;
+
+    if (s->d1->handshake_read_seq == frag->msg_header.seq) {
+        unsigned long frag_len = frag->msg_header.frag_len;
+        pqueue_pop(s->d1->buffered_messages);
+
+        al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
+
+        if (al == 0) {          /* no alert */
+            unsigned char *p =
+                (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+            memcpy(&p[frag->msg_header.frag_off], frag->fragment,
+                   frag->msg_header.frag_len);
+        }
+
+        dtls1_hm_fragment_free(frag);
+        pitem_free(item);
+
+        if (al == 0) {
+            *ok = 1;
+            return frag_len;
+        }
+
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
+        s->init_num = 0;
+        *ok = 0;
+        return -1;
+    } else
+        return 0;
+}
+
+/*
+ * dtls1_max_handshake_message_len returns the maximum number of bytes
+ * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
+ * may be greater if the maximum certificate list size requires it.
+ */
+static unsigned long dtls1_max_handshake_message_len(const SSL *s)
+{
+    unsigned long max_len =
+        DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
+    if (max_len < (unsigned long)s->max_cert_list)
+        return s->max_cert_list;
+    return max_len;
+}
+
+static int
+dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
+{
+    hm_fragment *frag = NULL;
+    pitem *item = NULL;
+    int i = -1, is_complete;
+    unsigned char seq64be[8];
+    unsigned long frag_len = msg_hdr->frag_len;
+
+    if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
+        msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
+        goto err;
+
+    if (frag_len == 0)
+        return DTLS1_HM_FRAGMENT_RETRY;
+
+    /* Try to find item in queue */
+    memset(seq64be, 0, sizeof(seq64be));
+    seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
+    seq64be[7] = (unsigned char)msg_hdr->seq;
+    item = pqueue_find(s->d1->buffered_messages, seq64be);
+
+    if (item == NULL) {
+        frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
+        if (frag == NULL)
+            goto err;
+        memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
+        frag->msg_header.frag_len = frag->msg_header.msg_len;
+        frag->msg_header.frag_off = 0;
+    } else {
+        frag = (hm_fragment *)item->data;
+        if (frag->msg_header.msg_len != msg_hdr->msg_len) {
+            item = NULL;
+            frag = NULL;
+            goto err;
+        }
+    }
+
+    /*
+     * If message is already reassembled, this must be a retransmit and can
+     * be dropped. In this case item != NULL and so frag does not need to be
+     * freed.
+     */
+    if (frag->reassembly == NULL) {
+        unsigned char devnull[256];
+
+        while (frag_len) {
+            i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
+                                          devnull,
+                                          frag_len >
+                                          sizeof(devnull) ? sizeof(devnull) :
+                                          frag_len, 0);
+            if (i <= 0)
+                goto err;
+            frag_len -= i;
+        }
+        return DTLS1_HM_FRAGMENT_RETRY;
+    }
+
+    /* read the body of the fragment (header has already been read */
+    i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
+                                  frag->fragment + msg_hdr->frag_off,
+                                  frag_len, 0);
+    if ((unsigned long)i != frag_len)
+        i = -1;
+    if (i <= 0)
+        goto err;
+
+    RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
+                        (long)(msg_hdr->frag_off + frag_len));
+
+    RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
+                               is_complete);
+
+    if (is_complete) {
+        OPENSSL_free(frag->reassembly);
+        frag->reassembly = NULL;
+    }
+
+    if (item == NULL) {
+        item = pitem_new(seq64be, frag);
+        if (item == NULL) {
+            i = -1;
+            goto err;
+        }
+
+        item = pqueue_insert(s->d1->buffered_messages, item);
+        /*
+         * pqueue_insert fails iff a duplicate item is inserted. However,
+         * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
+         * would have returned it and control would never have reached this
+         * branch.
+         */
+        OPENSSL_assert(item != NULL);
+    }
+
+    return DTLS1_HM_FRAGMENT_RETRY;
+
+ err:
+    if (frag != NULL && item == NULL)
+        dtls1_hm_fragment_free(frag);
+    *ok = 0;
+    return i;
+}
+
+static int
+dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
+                                 int *ok)
+{
+    int i = -1;
+    hm_fragment *frag = NULL;
+    pitem *item = NULL;
+    unsigned char seq64be[8];
+    unsigned long frag_len = msg_hdr->frag_len;
+
+    if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
+        goto err;
+
+    /* Try to find item in queue, to prevent duplicate entries */
+    memset(seq64be, 0, sizeof(seq64be));
+    seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
+    seq64be[7] = (unsigned char)msg_hdr->seq;
+    item = pqueue_find(s->d1->buffered_messages, seq64be);
+
+    /*
+     * If we already have an entry and this one is a fragment, don't discard
+     * it and rather try to reassemble it.
+     */
+    if (item != NULL && frag_len != msg_hdr->msg_len)
+        item = NULL;
+
+    /*
+     * Discard the message if sequence number was already there, is too far
+     * in the future, already in the queue or if we received a FINISHED
+     * before the SERVER_HELLO, which then must be a stale retransmit.
+     */
+    if (msg_hdr->seq <= s->d1->handshake_read_seq ||
+        msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
+        (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
+    {
+        unsigned char devnull[256];
+
+        while (frag_len) {
+            i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
+                                          devnull,
+                                          frag_len >
+                                          sizeof(devnull) ? sizeof(devnull) :
+                                          frag_len, 0);
+            if (i <= 0)
+                goto err;
+            frag_len -= i;
+        }
+    } else {
+        if (frag_len != msg_hdr->msg_len)
+            return dtls1_reassemble_fragment(s, msg_hdr, ok);
+
+        if (frag_len > dtls1_max_handshake_message_len(s))
+            goto err;
+
+        frag = dtls1_hm_fragment_new(frag_len, 0);
+        if (frag == NULL)
+            goto err;
+
+        memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
+
+        if (frag_len) {
+            /*
+             * read the body of the fragment (header has already been read
+             */
+            i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
+                                          frag->fragment, frag_len, 0);
+            if ((unsigned long)i != frag_len)
+                i = -1;
+            if (i <= 0)
+                goto err;
+        }
+
+        item = pitem_new(seq64be, frag);
+        if (item == NULL)
+            goto err;
+
+        item = pqueue_insert(s->d1->buffered_messages, item);
+        /*
+         * pqueue_insert fails iff a duplicate item is inserted. However,
+         * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
+         * would have returned it. Then, either |frag_len| !=
+         * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
+         * have been processed with |dtls1_reassemble_fragment|, above, or
+         * the record will have been discarded.
+         */
+        OPENSSL_assert(item != NULL);
+    }
+
+    return DTLS1_HM_FRAGMENT_RETRY;
+
+ err:
+    if (frag != NULL && item == NULL)
+        dtls1_hm_fragment_free(frag);
+    *ok = 0;
+    return i;
+}
+
+static long
+dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
+{
+    unsigned char wire[DTLS1_HM_HEADER_LENGTH];
+    unsigned long len, frag_off, frag_len;
+    int i, al;
+    struct hm_header_st msg_hdr;
+
+ redo:
+    /* see if we have the required fragment already */
+    if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
+        if (*ok)
+            s->init_num = frag_len;
+        return frag_len;
+    }
+
+    /* read handshake message header */
+    i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
+                                  DTLS1_HM_HEADER_LENGTH, 0);
+    if (i <= 0) {               /* nbio, or an error */
+        s->rwstate = SSL_READING;
+        *ok = 0;
+        return i;
+    }
+    /* Handshake fails if message header is incomplete */
+    if (i != DTLS1_HM_HEADER_LENGTH) {
+        al = SSL_AD_UNEXPECTED_MESSAGE;
+        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
+        goto f_err;
+    }
+
+    /* parse the message fragment header */
+    dtls1_get_message_header(wire, &msg_hdr);
+
+    len = msg_hdr.msg_len;
+    frag_off = msg_hdr.frag_off;
+    frag_len = msg_hdr.frag_len;
+
+    /*
+     * We must have at least frag_len bytes left in the record to be read.
+     * Fragments must not span records.
+     */
+    if (frag_len > s->s3->rrec.length) {
+        al = SSL3_AD_ILLEGAL_PARAMETER;
+        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
+        goto f_err;
+    }
+
+    /*
+     * if this is a future (or stale) message it gets buffered
+     * (or dropped)--no further processing at this time
+     * While listening, we accept seq 1 (ClientHello with cookie)
+     * although we're still expecting seq 0 (ClientHello)
+     */
+    if (msg_hdr.seq != s->d1->handshake_read_seq
+        && !(s->d1->listen && msg_hdr.seq == 1))
+        return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
+
+    if (frag_len && frag_len < len)
+        return dtls1_reassemble_fragment(s, &msg_hdr, ok);
+
+    if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
+        wire[0] == SSL3_MT_HELLO_REQUEST) {
+        /*
+         * The server may always send 'Hello Request' messages -- we are
+         * doing a handshake anyway now, so ignore them if their format is
+         * correct. Does not count for 'Finished' MAC.
+         */
+        if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
+            if (s->msg_callback)
+                s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
+                                wire, DTLS1_HM_HEADER_LENGTH, s,
+                                s->msg_callback_arg);
+
+            s->init_num = 0;
+            goto redo;
+        } else {                /* Incorrectly formated Hello request */
+
+            al = SSL_AD_UNEXPECTED_MESSAGE;
+            SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
+                   SSL_R_UNEXPECTED_MESSAGE);
+            goto f_err;
+        }
+    }
+
+    if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
+        goto f_err;
+
+    if (frag_len > 0) {
+        unsigned char *p =
+            (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
+
+        i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
+                                      &p[frag_off], frag_len, 0);
+
+        /*
+         * This shouldn't ever fail due to NBIO because we already checked
+         * that we have enough data in the record
+         */
+        if (i <= 0) {
+            s->rwstate = SSL_READING;
+            *ok = 0;
+            return i;
+        }
+    } else
+        i = 0;
+
+    /*
+     * XDTLS: an incorrectly formatted fragment should cause the handshake
+     * to fail
+     */
+    if (i != (int)frag_len) {
+        al = SSL3_AD_ILLEGAL_PARAMETER;
+        SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
+        goto f_err;
+    }
+
+    *ok = 1;
+    s->state = stn;
+
+    /*
+     * Note that s->init_num is *not* used as current offset in
+     * s->init_buf->data, but as a counter summing up fragments' lengths: as
+     * soon as they sum up to handshake packet length, we assume we have got
+     * all the fragments.
+     */
+    s->init_num = frag_len;
+    return frag_len;
+
+ f_err:
+    ssl3_send_alert(s, SSL3_AL_FATAL, al);
+    s->init_num = 0;
+
+    *ok = 0;
+    return (-1);
+}
+
+/*-
+ * for these 2 messages, we need to
+ * ssl->enc_read_ctx                    re-init
+ * ssl->s3->read_sequence               zero
+ * ssl->s3->read_mac_secret             re-init
+ * ssl->session->read_sym_enc           assign
+ * ssl->session->read_compression       assign
+ * ssl->session->read_hash              assign
+ */
+int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
+{
+    unsigned char *p;
+
+    if (s->state == a) {
+        p = (unsigned char *)s->init_buf->data;
+        *p++ = SSL3_MT_CCS;
+        s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
+        s->init_num = DTLS1_CCS_HEADER_LENGTH;
+
+        if (s->version == DTLS1_BAD_VER) {
+            s->d1->next_handshake_write_seq++;
+            s2n(s->d1->handshake_write_seq, p);
+            s->init_num += 2;
+        }
+
+        s->init_off = 0;
+
+        dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
+                                     s->d1->handshake_write_seq, 0, 0);
+
+        /* buffer the message to handle re-xmits */
+        dtls1_buffer_message(s, 1);
+
+        s->state = b;
+    }
+
+    /* SSL3_ST_CW_CHANGE_B */
+    return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
+}
+
+int dtls1_read_failed(SSL *s, int code)
+{
+    if (code > 0) {
+        fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
+        return 1;
+    }
+
+    if (!dtls1_is_timer_expired(s)) {
+        /*
+         * not a timeout, none of our business, let higher layers handle
+         * this.  in fact it's probably an error
+         */
+        return code;
+    }
+#ifndef OPENSSL_NO_HEARTBEATS
+    /* done, no need to send a retransmit */
+    if (!SSL_in_init(s) && !s->tlsext_hb_pending)
+#else
+    /* done, no need to send a retransmit */
+    if (!SSL_in_init(s))
+#endif
+    {
+        BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
+        return code;
+    }
+#if 0                           /* for now, each alert contains only one
+                                 * record number */
+    item = pqueue_peek(state->rcvd_records);
+    if (item) {
+        /* send an alert immediately for all the missing records */
+    } else
+#endif
+
+#if 0                           /* no more alert sending, just retransmit the
+                                 * last set of messages */
+    if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
+        ssl3_send_alert(s, SSL3_AL_WARNING,
+                        DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
+#endif
+
+    return dtls1_handle_timeout(s);
+}
+
+int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
+{
+    /*
+     * The index of the retransmission queue actually is the message sequence
+     * number, since the queue only contains messages of a single handshake.
+     * However, the ChangeCipherSpec has no message sequence number and so
+     * using only the sequence will result in the CCS and Finished having the
+     * same index. To prevent this, the sequence number is multiplied by 2.
+     * In case of a CCS 1 is subtracted. This does not only differ CSS and
+     * Finished, it also maintains the order of the index (important for
+     * priority queues) and fits in the unsigned short variable.
+     */
+    return seq * 2 - is_ccs;
+}
+
+int dtls1_retransmit_buffered_messages(SSL *s)
+{
+    pqueue sent = s->d1->sent_messages;
+    piterator iter;
+    pitem *item;
+    hm_fragment *frag;
+    int found = 0;
+
+    iter = pqueue_iterator(sent);
+
+    for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
+        frag = (hm_fragment *)item->data;
+        if (dtls1_retransmit_message(s, (unsigned short)
+                                     dtls1_get_queue_priority
+                                     (frag->msg_header.seq,
+                                      frag->msg_header.is_ccs), 0,
+                                     &found) <= 0 && found) {
+            fprintf(stderr, "dtls1_retransmit_message() failed\n");
+            return -1;
+        }
+    }
+
+    return 1;
+}
+
+int dtls1_buffer_message(SSL *s, int is_ccs)
+{
+    pitem *item;
+    hm_fragment *frag;
+    unsigned char seq64be[8];
+
+    /*
+     * this function is called immediately after a message has been
+     * serialized
+     */
+    OPENSSL_assert(s->init_off == 0);
+
+    frag = dtls1_hm_fragment_new(s->init_num, 0);
+    if (!frag)
+        return 0;
+
+    memcpy(frag->fragment, s->init_buf->data, s->init_num);
+
+    if (is_ccs) {
+        /* For DTLS1_BAD_VER the header length is non-standard */
+        OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
+                       ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
+                       == (unsigned int)s->init_num);
+    } else {
+        OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
+                       DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
+    }
+
+    frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
+    frag->msg_header.seq = s->d1->w_msg_hdr.seq;
+    frag->msg_header.type = s->d1->w_msg_hdr.type;
+    frag->msg_header.frag_off = 0;
+    frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
+    frag->msg_header.is_ccs = is_ccs;
+
+    /* save current state */
+    frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
+    frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
+    frag->msg_header.saved_retransmit_state.compress = s->compress;
+    frag->msg_header.saved_retransmit_state.session = s->session;
+    frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
+
+    memset(seq64be, 0, sizeof(seq64be));
+    seq64be[6] =
+        (unsigned
+         char)(dtls1_get_queue_priority(frag->msg_header.seq,
+                                        frag->msg_header.is_ccs) >> 8);
+    seq64be[7] =
+        (unsigned
+         char)(dtls1_get_queue_priority(frag->msg_header.seq,
+                                        frag->msg_header.is_ccs));
+
+    item = pitem_new(seq64be, frag);
+    if (item == NULL) {
+        dtls1_hm_fragment_free(frag);
+        return 0;
+    }
+#if 0
+    fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
+    fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
+    fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
+#endif
+
+    pqueue_insert(s->d1->sent_messages, item);
+    return 1;
+}
+
+int
+dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
+                         int *found)
+{
+    int ret;
+    /* XDTLS: for now assuming that read/writes are blocking */
+    pitem *item;
+    hm_fragment *frag;
+    unsigned long header_length;
+    unsigned char seq64be[8];
+    struct dtls1_retransmit_state saved_state;
+    unsigned char save_write_sequence[8] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+    /*-
+      OPENSSL_assert(s->init_num == 0);
+      OPENSSL_assert(s->init_off == 0);
+     */
+
+    /* XDTLS:  the requested message ought to be found, otherwise error */
+    memset(seq64be, 0, sizeof(seq64be));
+    seq64be[6] = (unsigned char)(seq >> 8);
+    seq64be[7] = (unsigned char)seq;
+
+    item = pqueue_find(s->d1->sent_messages, seq64be);
+    if (item == NULL) {
+        fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
+        *found = 0;
+        return 0;
+    }
+
+    *found = 1;
+    frag = (hm_fragment *)item->data;
+
+    if (frag->msg_header.is_ccs)
+        header_length = DTLS1_CCS_HEADER_LENGTH;
+    else
+        header_length = DTLS1_HM_HEADER_LENGTH;
+
+    memcpy(s->init_buf->data, frag->fragment,
+           frag->msg_header.msg_len + header_length);
+    s->init_num = frag->msg_header.msg_len + header_length;
+
+    dtls1_set_message_header_int(s, frag->msg_header.type,
+                                 frag->msg_header.msg_len,
+                                 frag->msg_header.seq, 0,
+                                 frag->msg_header.frag_len);
+
+    /* save current state */
+    saved_state.enc_write_ctx = s->enc_write_ctx;
+    saved_state.write_hash = s->write_hash;
+    saved_state.compress = s->compress;
+    saved_state.session = s->session;
+    saved_state.epoch = s->d1->w_epoch;
+    saved_state.epoch = s->d1->w_epoch;
+
+    s->d1->retransmitting = 1;
+
+    /* restore state in which the message was originally sent */
+    s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
+    s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
+    s->compress = frag->msg_header.saved_retransmit_state.compress;
+    s->session = frag->msg_header.saved_retransmit_state.session;
+    s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
+
+    if (frag->msg_header.saved_retransmit_state.epoch ==
+        saved_state.epoch - 1) {
+        memcpy(save_write_sequence, s->s3->write_sequence,
+               sizeof(s->s3->write_sequence));
+        memcpy(s->s3->write_sequence, s->d1->last_write_sequence,
+               sizeof(s->s3->write_sequence));
+    }
+
+    ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
+                         SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
+
+    /* restore current state */
+    s->enc_write_ctx = saved_state.enc_write_ctx;
+    s->write_hash = saved_state.write_hash;
+    s->compress = saved_state.compress;
+    s->session = saved_state.session;
+    s->d1->w_epoch = saved_state.epoch;
+
+    if (frag->msg_header.saved_retransmit_state.epoch ==
+        saved_state.epoch - 1) {
+        memcpy(s->d1->last_write_sequence, s->s3->write_sequence,
+               sizeof(s->s3->write_sequence));
+        memcpy(s->s3->write_sequence, save_write_sequence,
+               sizeof(s->s3->write_sequence));
+    }
+
+    s->d1->retransmitting = 0;
+
+    (void)BIO_flush(SSL_get_wbio(s));
+    return ret;
+}
+
+unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p,
+                                        unsigned char mt, unsigned long len,
+                                        unsigned long frag_off,
+                                        unsigned long frag_len)
+{
+    /* Don't change sequence numbers while listening */
+    if (frag_off == 0 && !s->d1->listen) {
+        s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
+        s->d1->next_handshake_write_seq++;
+    }
+
+    dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
+                                 frag_off, frag_len);
+
+    return p += DTLS1_HM_HEADER_LENGTH;
+}
+
+/* don't actually do the writing, wait till the MTU has been retrieved */
+static void
+dtls1_set_message_header_int(SSL *s, unsigned char mt,
+                             unsigned long len, unsigned short seq_num,
+                             unsigned long frag_off, unsigned long frag_len)
+{
+    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+    msg_hdr->type = mt;
+    msg_hdr->msg_len = len;
+    msg_hdr->seq = seq_num;
+    msg_hdr->frag_off = frag_off;
+    msg_hdr->frag_len = frag_len;
+}
+
+static void
+dtls1_fix_message_header(SSL *s, unsigned long frag_off,
+                         unsigned long frag_len)
+{
+    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+    msg_hdr->frag_off = frag_off;
+    msg_hdr->frag_len = frag_len;
+}
+
+static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
+{
+    struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
+
+    *p++ = msg_hdr->type;
+    l2n3(msg_hdr->msg_len, p);
+
+    s2n(msg_hdr->seq, p);
+    l2n3(msg_hdr->frag_off, p);
+    l2n3(msg_hdr->frag_len, p);
+
+    return p;
+}
+
+unsigned int dtls1_link_min_mtu(void)
+{
+    return (g_probable_mtu[(sizeof(g_probable_mtu) /
+                            sizeof(g_probable_mtu[0])) - 1]);
+}
+
+unsigned int dtls1_min_mtu(SSL *s)
+{
+    return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
+}
+
+void
+dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
+{
+    memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
+    msg_hdr->type = *(data++);
+    n2l3(data, msg_hdr->msg_len);
+
+    n2s(data, msg_hdr->seq);
+    n2l3(data, msg_hdr->frag_off);
+    n2l3(data, msg_hdr->frag_len);
+}
+
+void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
+{
+    memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
+
+    ccs_hdr->type = *(data++);
+}
+
+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)
+            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
+                     NULL);
+    }
+#endif
+    ret = ssl3_shutdown(s);
+#ifndef OPENSSL_NO_SCTP
+    BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
+#endif
+    return ret;
+}
+
+#ifndef OPENSSL_NO_HEARTBEATS
+int dtls1_process_heartbeat(SSL *s)
+{
+    unsigned char *p = &s->s3->rrec.data[0], *pl;
+    unsigned short hbtype;
+    unsigned int payload;
+    unsigned int padding = 16;  /* Use minimum padding */
+
+    if (s->msg_callback)
+        s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
+                        &s->s3->rrec.data[0], s->s3->rrec.length,
+                        s, s->msg_callback_arg);
+
+    /* Read type and payload length first */
+    if (1 + 2 + 16 > s->s3->rrec.length)
+        return 0;               /* silently discard */
+    if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
+        return 0;               /* silently discard per RFC 6520 sec. 4 */
+
+    hbtype = *p++;
+    n2s(p, payload);
+    if (1 + 2 + payload + 16 > s->s3->rrec.length)
+        return 0;               /* silently discard per RFC 6520 sec. 4 */
+    pl = p;
+
+    if (hbtype == TLS1_HB_REQUEST) {
+        unsigned char *buffer, *bp;
+        unsigned int write_length = 1 /* heartbeat type */  +
+            2 /* heartbeat length */  +
+            payload + padding;
+        int r;
+
+        if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
+            return 0;
+
+        /*
+         * Allocate memory for the response, size is 1 byte message type,
+         * plus 2 bytes payload length, plus payload, plus padding
+         */
+        buffer = OPENSSL_malloc(write_length);
+        if (buffer == NULL)
+            return -1;
+        bp = buffer;
+
+        /* Enter response type, length and copy payload */
+        *bp++ = TLS1_HB_RESPONSE;
+        s2n(payload, bp);
+        memcpy(bp, pl, payload);
+        bp += payload;
+        /* Random padding */
+        if (RAND_bytes(bp, padding) <= 0) {
+            OPENSSL_free(buffer);
+            return -1;
+        }
+
+        r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
+
+        if (r >= 0 && s->msg_callback)
+            s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                            buffer, write_length, s, s->msg_callback_arg);
+
+        OPENSSL_free(buffer);
+
+        if (r < 0)
+            return r;
+    } else if (hbtype == TLS1_HB_RESPONSE) {
+        unsigned int seq;
+
+        /*
+         * We only send sequence numbers (2 bytes unsigned int), and 16
+         * random bytes, so we just try to read the sequence number
+         */
+        n2s(pl, seq);
+
+        if (payload == 18 && seq == s->tlsext_hb_seq) {
+            dtls1_stop_timer(s);
+            s->tlsext_hb_seq++;
+            s->tlsext_hb_pending = 0;
+        }
+    }
+
+    return 0;
+}
+
+int dtls1_heartbeat(SSL *s)
+{
+    unsigned char *buf, *p;
+    int ret = -1;
+    unsigned int payload = 18;  /* Sequence number + random bytes */
+    unsigned int padding = 16;  /* Use minimum padding */
+
+    /* Only send if peer supports and accepts HB requests... */
+    if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
+        s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
+        return -1;
+    }
+
+    /* ...and there is none in flight yet... */
+    if (s->tlsext_hb_pending) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
+        return -1;
+    }
+
+    /* ...and no handshake in progress. */
+    if (SSL_in_init(s) || s->in_handshake) {
+        SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
+        return -1;
+    }
+
+    /*
+     * Check if padding is too long, payload and padding must not exceed 2^14
+     * - 3 = 16381 bytes in total.
+     */
+    OPENSSL_assert(payload + padding <= 16381);
+
+    /*-
+     * Create HeartBeat message, we just use a sequence number
+     * as payload to distuingish different messages and add
+     * some random stuff.
+     *  - Message Type, 1 byte
+     *  - Payload Length, 2 bytes (unsigned int)
+     *  - Payload, the sequence number (2 bytes uint)
+     *  - Payload, random bytes (16 bytes uint)
+     *  - Padding
+     */
+    buf = OPENSSL_malloc(1 + 2 + payload + padding);
+    if (buf == NULL)
+        goto err;
+    p = buf;
+    /* Message Type */
+    *p++ = TLS1_HB_REQUEST;
+    /* Payload length (18 bytes here) */
+    s2n(payload, p);
+    /* Sequence number */
+    s2n(s->tlsext_hb_seq, p);
+    /* 16 random bytes */
+    if (RAND_bytes(p, 16) <= 0)
+        goto err;
+    p += 16;
+    /* Random padding */
+    if (RAND_bytes(p, padding) <= 0)
+        goto err;
+
+    ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
+    if (ret >= 0) {
+        if (s->msg_callback)
+            s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
+                            buf, 3 + payload + padding,
+                            s, s->msg_callback_arg);
+
+        dtls1_start_timer(s);
+        s->tlsext_hb_pending = 1;
+    }
+
+err:
+    OPENSSL_free(buf);
+
+    return ret;
+}
+#endif