update libressl to 2.8.2

[unleashed.git] / lib / libssl / ssl_pkt.c

/* $OpenBSD: ssl_pkt.c,v 1.13 2018/09/08 14:39:41 jsing Exp $ */
/* 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.]
 */
/* ====================================================================
 * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <errno.h>
#include <stdio.h>

#include "ssl_locl.h"

#include <openssl/buffer.h>
#include <openssl/evp.h>

#include "bytestring.h"

static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
    unsigned int len, int create_empty_fragment);
static int ssl3_get_record(SSL *s);

/*
 * Force a WANT_READ return for certain error conditions where
 * we don't want to spin internally.
 */
static void
ssl_force_want_read(SSL *s)
{
        BIO * bio;

        bio = SSL_get_rbio(s);
        BIO_clear_retry_flags(bio);
        BIO_set_retry_read(bio);
        s->internal->rwstate = SSL_READING;
}

/*
 * If extend == 0, obtain new n-byte packet; if extend == 1, increase
 * packet by another n bytes.
 * The packet will be in the sub-array of s->s3->rbuf.buf specified
 * by s->internal->packet and s->internal->packet_length.
 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf
 * [plus s->internal->packet_length bytes if extend == 1].)
 */
static int
ssl3_read_n(SSL *s, int n, int max, int extend)
{
        int i, len, left;
        size_t align;
        unsigned char *pkt;
        SSL3_BUFFER *rb;

        if (n <= 0)
                return n;

        rb = &(s->s3->rbuf);
        if (rb->buf == NULL)
                if (!ssl3_setup_read_buffer(s))
                        return -1;

        left = rb->left;
        align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH;
        align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);

        if (!extend) {
                /* start with empty packet ... */
                if (left == 0)
                        rb->offset = align;
                else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) {
                        /* check if next packet length is large
                         * enough to justify payload alignment... */
                        pkt = rb->buf + rb->offset;
                        if (pkt[0] == SSL3_RT_APPLICATION_DATA &&
                            (pkt[3]<<8|pkt[4]) >= 128) {
                                /* Note that even if packet is corrupted
                                 * and its length field is insane, we can
                                 * only be led to wrong decision about
                                 * whether memmove will occur or not.
                                 * Header values has no effect on memmove
                                 * arguments and therefore no buffer
                                 * overrun can be triggered. */
                                memmove(rb->buf + align, pkt, left);
                                rb->offset = align;
                        }
                }
                s->internal->packet = rb->buf + rb->offset;
                s->internal->packet_length = 0;
                /* ... now we can act as if 'extend' was set */
        }

        /* For DTLS/UDP reads should not span multiple packets
         * because the read operation returns the whole packet
         * at once (as long as it fits into the buffer). */
        if (SSL_IS_DTLS(s)) {
                if (left > 0 && n > left)
                        n = left;
        }

        /* if there is enough in the buffer from a previous read, take some */
        if (left >= n) {
                s->internal->packet_length += n;
                rb->left = left - n;
                rb->offset += n;
                return (n);
        }

        /* else we need to read more data */

        len = s->internal->packet_length;
        pkt = rb->buf + align;
        /* Move any available bytes to front of buffer:
         * 'len' bytes already pointed to by 'packet',
         * 'left' extra ones at the end */
        if (s->internal->packet != pkt)  {
                /* len > 0 */
                memmove(pkt, s->internal->packet, len + left);
                s->internal->packet = pkt;
                rb->offset = len + align;
        }

        if (n > (int)(rb->len - rb->offset)) {
                /* does not happen */
                SSLerror(s, ERR_R_INTERNAL_ERROR);
                return -1;
        }

        if (!s->internal->read_ahead) {
                /* ignore max parameter */
                max = n;
        } else {
                if (max < n)
                        max = n;
                if (max > (int)(rb->len - rb->offset))
                        max = rb->len - rb->offset;
        }

        while (left < n) {
                /* Now we have len+left bytes at the front of s->s3->rbuf.buf
                 * and need to read in more until we have len+n (up to
                 * len+max if possible) */

                errno = 0;
                if (s->rbio != NULL) {
                        s->internal->rwstate = SSL_READING;
                        i = BIO_read(s->rbio, pkt + len + left, max - left);
                } else {
                        SSLerror(s, SSL_R_READ_BIO_NOT_SET);
                        i = -1;
                }

                if (i <= 0) {
                        rb->left = left;
                        if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
                            !SSL_IS_DTLS(s)) {
                                if (len + left == 0)
                                        ssl3_release_read_buffer(s);
                        }
                        return (i);
                }
                left += i;

                /*
                 * reads should *never* span multiple packets for DTLS because
                 * the underlying transport protocol is message oriented as
                 * opposed to byte oriented as in the TLS case.
                 */
                if (SSL_IS_DTLS(s)) {
                        if (n > left)
                                n = left; /* makes the while condition false */
                }
        }

        /* done reading, now the book-keeping */
        rb->offset += n;
        rb->left = left - n;
        s->internal->packet_length += n;
        s->internal->rwstate = SSL_NOTHING;

        return (n);
}

int
ssl3_packet_read(SSL *s, int plen)
{
        int n;

        n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0);
        if (n <= 0)
                return n;
        if (s->internal->packet_length < plen)
                return s->internal->packet_length;

        return plen;
}

int
ssl3_packet_extend(SSL *s, int plen)
{
        int rlen, n;

        if (s->internal->packet_length >= plen)
                return plen;
        rlen = plen - s->internal->packet_length;

        n = ssl3_read_n(s, rlen, rlen, 1);
        if (n <= 0)
                return n;
        if (s->internal->packet_length < plen)
                return s->internal->packet_length;

        return plen;
}

/* 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->internal->rrec.type    - is the type of record
 * ssl->s3->internal->rrec.data,         - data
 * ssl->s3->internal->rrec.length, - number of bytes
 */
/* used only by ssl3_read_bytes */
static int
ssl3_get_record(SSL *s)
{
        int al;
        int enc_err, n, i, ret = -1;
        SSL3_RECORD *rr;
        SSL_SESSION *sess;
        unsigned char md[EVP_MAX_MD_SIZE];
        unsigned mac_size, orig_len;

        rr = &(S3I(s)->rrec);
        sess = s->session;

 again:
        /* check if we have the header */
        if ((s->internal->rstate != SSL_ST_READ_BODY) ||
            (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) {
                CBS header;
                uint16_t len, ssl_version;
                uint8_t type;

                n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH);
                if (n <= 0)
                        return (n);

                s->internal->mac_packet = 1;
                s->internal->rstate = SSL_ST_READ_BODY;

                if (s->server && s->internal->first_packet) {
                        if ((ret = ssl_server_legacy_first_packet(s)) != 1)
                                return (ret);
                        ret = -1;
                }

                CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH);

                /* Pull apart the header into the SSL3_RECORD */
                if (!CBS_get_u8(&header, &type) ||
                    !CBS_get_u16(&header, &ssl_version) ||
                    !CBS_get_u16(&header, &len)) {
                        SSLerror(s, SSL_R_BAD_PACKET_LENGTH);
                        goto err;
                }

                rr->type = type;
                rr->length = len;

                /* Lets check version */
                if (!s->internal->first_packet && ssl_version != s->version) {
                        SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
                        if ((s->version & 0xFF00) == (ssl_version & 0xFF00) &&
                            !s->internal->enc_write_ctx && !s->internal->write_hash)
                                /* Send back error using their minor version number :-) */
                                s->version = ssl_version;
                        al = SSL_AD_PROTOCOL_VERSION;
                        goto f_err;
                }

                if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) {
                        SSLerror(s, SSL_R_WRONG_VERSION_NUMBER);
                        goto err;
                }

                if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH) {
                        al = SSL_AD_RECORD_OVERFLOW;
                        SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG);
                        goto f_err;
                }

                /* now s->internal->rstate == SSL_ST_READ_BODY */
        }

        /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */

        n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length);
        if (n <= 0)
                return (n);
        if (n != SSL3_RT_HEADER_LENGTH + rr->length)
                return (n);

        s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */

        /* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
         * and we have that many bytes in s->internal->packet
         */
        rr->input = &(s->internal->packet[SSL3_RT_HEADER_LENGTH]);

        /* ok, we can now read from 's->internal->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;
                SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
                goto f_err;
        }

        /* decrypt in place in 'rr->input' */
        rr->data = rr->input;

        enc_err = s->method->internal->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) {
                al = SSL_AD_DECRYPTION_FAILED;
                SSLerror(s, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
                goto f_err;
        }


        /* 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;
                        SSLerror(s, 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 = tls1_mac(s,md,0 /* not send */);
                if (i < 0 || mac == NULL ||
                    timingsafe_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) {
                /*
                 * A separate 'decryption_failed' alert was introduced with
                 * TLS 1.0, SSL 3.0 only has 'bad_record_mac'. But unless a
                 * decryption failure is directly visible from the ciphertext
                 * anyway, we should not reveal which kind of error
                 * occurred -- this might become visible to an attacker
                 * (e.g. via a logfile)
                 */
                al = SSL_AD_BAD_RECORD_MAC;
                SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
                goto f_err;
        }

        if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
                al = SSL_AD_RECORD_OVERFLOW;
                SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG);
                goto f_err;
        }

        rr->off = 0;
        /*
         * So at this point the following is true
         *
         * ssl->s3->internal->rrec.type         is the type of record
         * ssl->s3->internal->rrec.length       == number of bytes in record
         * ssl->s3->internal->rrec.off  == offset to first valid byte
         * ssl->s3->internal->rrec.data == where to take bytes from, increment
         *                         after use :-).
         */

        /* we have pulled in a full packet so zero things */
        s->internal->packet_length = 0;

        if (rr->length == 0) {
                /*
                 * CBC countermeasures for known IV weaknesses
                 * can legitimately insert a single empty record,
                 * so we allow ourselves to read once past a single
                 * empty record without forcing want_read.
                 */
                if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) {
                        SSLerror(s, SSL_R_PEER_BEHAVING_BADLY);
                        return -1;
                }
                if (s->internal->empty_record_count > 1) {
                        ssl_force_want_read(s);
                        return -1;
                }
                goto again;
        } else {
                s->internal->empty_record_count = 0;
        }

        return (1);

f_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
        return (ret);
}

/* 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
ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
{
        const unsigned char *buf = buf_;
        unsigned int tot, n, nw;
        int i;

        if (len < 0) {
                SSLerror(s, ERR_R_INTERNAL_ERROR);
                return -1;
        }

        s->internal->rwstate = SSL_NOTHING;
        tot = S3I(s)->wnum;
        S3I(s)->wnum = 0;

        if (SSL_in_init(s) && !s->internal->in_handshake) {
                i = s->internal->handshake_func(s);
                if (i < 0)
                        return (i);
                if (i == 0) {
                        SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
                        return -1;
                }
        }

        if (len < tot)
                len = tot;
        n = (len - tot);
        for (;;) {
                if (n > s->max_send_fragment)
                        nw = s->max_send_fragment;
                else
                        nw = n;

                i = do_ssl3_write(s, type, &(buf[tot]), nw, 0);
                if (i <= 0) {
                        S3I(s)->wnum = tot;
                        return i;
                }

                if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA &&
                    (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) {
                        /*
                         * Next chunk of data should get another prepended
                         * empty fragment in ciphersuites with known-IV
                         * weakness.
                         */
                        S3I(s)->empty_fragment_done = 0;

                        return tot + i;
                }

                n -= i;
                tot += i;
        }
}

static int
do_ssl3_write(SSL *s, int type, const unsigned char *buf,
    unsigned int len, int create_empty_fragment)
{
        unsigned char *p, *plen;
        int i, mac_size, clear = 0;
        int prefix_len = 0;
        int eivlen;
        size_t align;
        SSL3_RECORD *wr;
        SSL3_BUFFER *wb = &(s->s3->wbuf);
        SSL_SESSION *sess;

        if (wb->buf == NULL)
                if (!ssl3_setup_write_buffer(s))
                        return -1;

        /* first check if there is a SSL3_BUFFER still being written
         * out.  This will happen with non blocking IO */
        if (wb->left != 0)
                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 */
                /* we may have released our buffer, so get it again */
                if (wb->buf == NULL)
                        if (!ssl3_setup_write_buffer(s))
                                return -1;
        }

        if (len == 0 && !create_empty_fragment)
                return 0;

        wr = &(S3I(s)->wrec);
        sess = s->session;

        if ((sess == NULL) || (s->internal->enc_write_ctx == NULL) ||
            (EVP_MD_CTX_md(s->internal->write_hash) == NULL)) {
                clear = s->internal->enc_write_ctx ? 0 : 1; /* must be AEAD cipher */
                mac_size = 0;
        } else {
                mac_size = EVP_MD_CTX_size(s->internal->write_hash);
                if (mac_size < 0)
                        goto err;
        }

        /*
         * 'create_empty_fragment' is true only when this function calls
         * itself.
         */
        if (!clear && !create_empty_fragment && !S3I(s)->empty_fragment_done) {
                /*
                 * Countermeasure against known-IV weakness in CBC ciphersuites
                 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
                 */
                if (S3I(s)->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 = do_ssl3_write(s, type, buf, 0, 1);
                        if (prefix_len <= 0)
                                goto err;

                        if (prefix_len >
                                (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) {
                                /* insufficient space */
                                SSLerror(s, ERR_R_INTERNAL_ERROR);
                                goto err;
                        }
                }

                S3I(s)->empty_fragment_done = 1;
        }

        if (create_empty_fragment) {
                /* extra fragment would be couple of cipher blocks,
                 * which would be multiple of SSL3_ALIGN_PAYLOAD, so
                 * if we want to align the real payload, then we can
                 * just pretent we simply have two headers. */
                align = (size_t)wb->buf + 2 * SSL3_RT_HEADER_LENGTH;
                align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);

                p = wb->buf + align;
                wb->offset = align;
        } else if (prefix_len) {
                p = wb->buf + wb->offset + prefix_len;
        } else {
                align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH;
                align = (-align) & (SSL3_ALIGN_PAYLOAD - 1);

                p = wb->buf + align;
                wb->offset = align;
        }

        /* write the header */

        *(p++) = type&0xff;
        wr->type = type;

        *(p++) = (s->version >> 8);
        /* Some servers hang if iniatial client hello is larger than 256
         * bytes and record version number > TLS 1.0
         */
        if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && !s->internal->renegotiate &&
            TLS1_get_version(s) > TLS1_VERSION)
                *(p++) = 0x1;
        else
                *(p++) = s->version&0xff;

        /* field where we are to write out packet length */
        plen = p;
        p += 2;

        /* Explicit IV length. */
        eivlen = 0;
        if (s->internal->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) {
                int mode = EVP_CIPHER_CTX_mode(s->internal->enc_write_ctx);
                if (mode == EVP_CIPH_CBC_MODE) {
                        eivlen = EVP_CIPHER_CTX_iv_length(s->internal->enc_write_ctx);
                        if (eivlen <= 1)
                                eivlen = 0;
                }
        } else if (s->internal->aead_write_ctx != NULL &&
            s->internal->aead_write_ctx->variable_nonce_in_record) {
                eivlen = s->internal->aead_write_ctx->variable_nonce_len;
        }

        /* lets setup the record stuff. */
        wr->data = p + eivlen;
        wr->length = (int)len;
        wr->input = (unsigned char *)buf;

        /* we now 'read' from wr->input, wr->length bytes into wr->data */

        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 (tls1_mac(s,
                    &(p[wr->length + eivlen]), 1) < 0)
                        goto err;
                wr->length += mac_size;
        }

        wr->input = p;
        wr->data = p;

        if (eivlen) {
                /* if (RAND_pseudo_bytes(p, eivlen) <= 0)
                        goto err;
                */
                wr->length += eivlen;
        }

        /* ssl3_enc can only have an error on read */
        s->method->internal->ssl3_enc->enc(s, 1);

        /* record length after mac and block padding */
        s2n(wr->length, plen);

        /* 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 += SSL3_RT_HEADER_LENGTH;

        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;

        /* memorize arguments so that ssl3_write_pending can detect
         * bad write retries later */
        S3I(s)->wpend_tot = len;
        S3I(s)->wpend_buf = buf;
        S3I(s)->wpend_type = type;
        S3I(s)->wpend_ret = len;

        /* we now just need to write the buffer */
        return ssl3_write_pending(s, type, buf, len);
err:
        return -1;
}

/* if s->s3->wbuf.left != 0, we need to call this */
int
ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len)
{
        int i;
        SSL3_BUFFER *wb = &(s->s3->wbuf);

        /* XXXX */
        if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) &&
            !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) ||
            (S3I(s)->wpend_type != type)) {
                SSLerror(s, SSL_R_BAD_WRITE_RETRY);
                return (-1);
        }

        for (;;) {
                errno = 0;
                if (s->wbio != NULL) {
                        s->internal->rwstate = SSL_WRITING;
                        i = BIO_write(s->wbio,
                        (char *)&(wb->buf[wb->offset]),
                        (unsigned int)wb->left);
                } else {
                        SSLerror(s, SSL_R_BIO_NOT_SET);
                        i = -1;
                }
                if (i == wb->left) {
                        wb->left = 0;
                        wb->offset += i;
                        if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
                            !SSL_IS_DTLS(s))
                                ssl3_release_write_buffer(s);
                        s->internal->rwstate = SSL_NOTHING;
                        return (S3I(s)->wpend_ret);
                } else if (i <= 0) {
                        /*
                         * For DTLS, just drop it. That's kind of the
                         * whole point in using a datagram service.
                         */
                        if (SSL_IS_DTLS(s))
                                wb->left = 0;
                        return (i);
                }
                wb->offset += i;
                wb->left -= i;
        }
}

/* 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
ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
{
        void (*cb)(const SSL *ssl, int type2, int val) = NULL;
        int al, i, j, ret, rrcount = 0;
        unsigned int n;
        SSL3_RECORD *rr;

        if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
                if (!ssl3_setup_read_buffer(s))
                        return (-1);

        if (len < 0) {
                SSLerror(s, ERR_R_INTERNAL_ERROR);
                return -1;
        }

        if ((type && type != SSL3_RT_APPLICATION_DATA &&
            type != SSL3_RT_HANDSHAKE) ||
            (peek && (type != SSL3_RT_APPLICATION_DATA))) {
                SSLerror(s, ERR_R_INTERNAL_ERROR);
                return -1;
        }

        if ((type == SSL3_RT_HANDSHAKE) &&
            (S3I(s)->handshake_fragment_len > 0)) {
                /* (partially) satisfy request from storage */
                unsigned char *src = S3I(s)->handshake_fragment;
                unsigned char *dst = buf;
                unsigned int k;

                /* peek == 0 */
                n = 0;
                while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) {
                        *dst++ = *src++;
                        len--;
                        S3I(s)->handshake_fragment_len--;
                        n++;
                }
                /* move any remaining fragment bytes: */
                for (k = 0; k < S3I(s)->handshake_fragment_len; k++)
                        S3I(s)->handshake_fragment[k] = *src++;
                return n;
        }

        /*
         * Now S3I(s)->handshake_fragment_len == 0 if
         * type == SSL3_RT_HANDSHAKE.
         */
        if (!s->internal->in_handshake && SSL_in_init(s)) {
                /* type == SSL3_RT_APPLICATION_DATA */
                i = s->internal->handshake_func(s);
                if (i < 0)
                        return (i);
                if (i == 0) {
                        SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
                        return (-1);
                }
        }

start:
        /*
         * Do not process more than three consecutive records, otherwise the
         * peer can cause us to loop indefinitely. Instead, return with an
         * SSL_ERROR_WANT_READ so the caller can choose when to handle further
         * processing. In the future, the total number of non-handshake and
         * non-application data records per connection should probably also be
         * limited...
         */
        if (rrcount++ >= 3) {
                ssl_force_want_read(s);
                return -1;
        }

        s->internal->rwstate = SSL_NOTHING;

        /*
         * S3I(s)->rrec.type        - is the type of record
         * S3I(s)->rrec.data,    - data
         * S3I(s)->rrec.off,     - offset into 'data' for next read
         * S3I(s)->rrec.length,  - number of bytes.
         */
        rr = &(S3I(s)->rrec);

        /* get new packet if necessary */
        if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) {
                ret = ssl3_get_record(s);
                if (ret <= 0)
                        return (ret);
        }

        /* we now have a packet which can be read and processed */

        if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec,
                                       * reset by ssl3_get_finished */
            && (rr->type != SSL3_RT_HANDSHAKE)) {
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
                goto f_err;
        }

        /* If the other end has shut down, throw anything we read away
         * (even in 'peek' mode) */
        if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) {
                rr->length = 0;
                s->internal->rwstate = SSL_NOTHING;
                return (0);
        }


        /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
        if (type == rr->type) {
                /* 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;
                        SSLerror(s, 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) {
                        memset(&(rr->data[rr->off]), 0, n);
                        rr->length -= n;
                        rr->off += n;
                        if (rr->length == 0) {
                                s->internal->rstate = SSL_ST_READ_HEADER;
                                rr->off = 0;
                                if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS &&
                                    s->s3->rbuf.left == 0)
                                        ssl3_release_read_buffer(s);
                        }
                }
                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 dest_maxlen = 0;
                unsigned char *dest = NULL;
                unsigned int *dest_len = NULL;

                if (rr->type == SSL3_RT_HANDSHAKE) {
                        dest_maxlen = sizeof S3I(s)->handshake_fragment;
                        dest = S3I(s)->handshake_fragment;
                        dest_len = &S3I(s)->handshake_fragment_len;
                } else if (rr->type == SSL3_RT_ALERT) {
                        dest_maxlen = sizeof S3I(s)->alert_fragment;
                        dest = S3I(s)->alert_fragment;
                        dest_len = &S3I(s)->alert_fragment_len;
                }
                if (dest_maxlen > 0) {
                        /* available space in 'dest' */
                        n = dest_maxlen - *dest_len;
                        if (rr->length < n)
                                n = rr->length; /* available bytes */

                        /* now move 'n' bytes: */
                        while (n-- > 0) {
                                dest[(*dest_len)++] = rr->data[rr->off++];
                                rr->length--;
                        }

                        if (*dest_len < dest_maxlen)
                                goto start; /* fragment was too small */
                }
        }

        /* S3I(s)->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
         * S3I(s)->alert_fragment_len == 2      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) && (S3I(s)->handshake_fragment_len >= 4) &&
            (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
            (s->session != NULL) && (s->session->cipher != NULL)) {
                S3I(s)->handshake_fragment_len = 0;

                if ((S3I(s)->handshake_fragment[1] != 0) ||
                    (S3I(s)->handshake_fragment[2] != 0) ||
                    (S3I(s)->handshake_fragment[3] != 0)) {
                        al = SSL_AD_DECODE_ERROR;
                        SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
                        goto f_err;
                }

                if (s->internal->msg_callback)
                        s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
                            S3I(s)->handshake_fragment, 4, s,
                            s->internal->msg_callback_arg);

                if (SSL_is_init_finished(s) &&
                    !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
                    !S3I(s)->renegotiate) {
                        ssl3_renegotiate(s);
                        if (ssl3_renegotiate_check(s)) {
                                i = s->internal->handshake_func(s);
                                if (i < 0)
                                        return (i);
                                if (i == 0) {
                                        SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
                                        return (-1);
                                }

                                if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
                                        if (s->s3->rbuf.left == 0) {
                                                /* no read-ahead left? */
                        /* 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 */
                                                ssl_force_want_read(s);
                                                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;
        }
        /* Disallow client initiated renegotiation if configured. */
        if (s->server && SSL_is_init_finished(s) &&
            S3I(s)->handshake_fragment_len >= 4 &&
            S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO &&
            (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) {
                al = SSL_AD_NO_RENEGOTIATION;
                goto f_err;
        }
        /* If we are a server and get a client hello when renegotiation isn't
         * allowed send back a no renegotiation alert and carry on.
         * WARNING: experimental code, needs reviewing (steve)
         */
        if (s->server &&
            SSL_is_init_finished(s) &&
            !S3I(s)->send_connection_binding &&
            (S3I(s)->handshake_fragment_len >= 4) &&
            (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
            (s->session != NULL) && (s->session->cipher != NULL)) {
                /*S3I(s)->handshake_fragment_len = 0;*/
                rr->length = 0;
                ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
                goto start;
        }
        if (S3I(s)->alert_fragment_len >= 2) {
                int alert_level = S3I(s)->alert_fragment[0];
                int alert_descr = S3I(s)->alert_fragment[1];

                S3I(s)->alert_fragment_len = 0;

                if (s->internal->msg_callback)
                        s->internal->msg_callback(0, s->version, SSL3_RT_ALERT,
                            S3I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg);

                if (s->internal->info_callback != NULL)
                        cb = s->internal->info_callback;
                else if (s->ctx->internal->info_callback != NULL)
                        cb = s->ctx->internal->info_callback;

                if (cb != NULL) {
                        j = (alert_level << 8) | alert_descr;
                        cb(s, SSL_CB_READ_ALERT, j);
                }

                if (alert_level == SSL3_AL_WARNING) {
                        S3I(s)->warn_alert = alert_descr;
                        if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
                                s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
                                return (0);
                        }
                        /* This is a warning but we receive it if we requested
                         * renegotiation and the peer denied it. Terminate with
                         * a fatal alert because if application tried to
                         * renegotiatie it presumably had a good reason and
                         * expects it to succeed.
                         *
                         * In future we might have a renegotiation where we
                         * don't care if the peer refused it where we carry on.
                         */
                        else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
                                al = SSL_AD_HANDSHAKE_FAILURE;
                                SSLerror(s, SSL_R_NO_RENEGOTIATION);
                                goto f_err;
                        }
                } else if (alert_level == SSL3_AL_FATAL) {
                        s->internal->rwstate = SSL_NOTHING;
                        S3I(s)->fatal_alert = alert_descr;
                        SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
                        ERR_asprintf_error_data("SSL alert number %d",
                            alert_descr);
                        s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
                        SSL_CTX_remove_session(s->ctx, s->session);
                        return (0);
                } else {
                        al = SSL_AD_ILLEGAL_PARAMETER;
                        SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
                        goto f_err;
                }

                goto start;
        }

        if (s->internal->shutdown & SSL_SENT_SHUTDOWN) {
                /* but we have not received a shutdown */
                s->internal->rwstate = SSL_NOTHING;
                rr->length = 0;
                return (0);
        }

        if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
                /* 'Change Cipher Spec' is just a single byte, so we know
                 * exactly what the record payload has to look like */
                if ((rr->length != 1) || (rr->off != 0) ||
                        (rr->data[0] != SSL3_MT_CCS)) {
                        al = SSL_AD_ILLEGAL_PARAMETER;
                        SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
                        goto f_err;
                }

                /* Check we have a cipher to change to */
                if (S3I(s)->hs.new_cipher == NULL) {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
                        goto f_err;
                }

                /* Check that we should be receiving a Change Cipher Spec. */
                if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
                        goto f_err;
                }
                s->s3->flags &= ~SSL3_FLAGS_CCS_OK;

                rr->length = 0;

                if (s->internal->msg_callback) {
                        s->internal->msg_callback(0, s->version,
                            SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s,
                            s->internal->msg_callback_arg);
                }

                S3I(s)->change_cipher_spec = 1;
                if (!ssl3_do_change_cipher_spec(s))
                        goto err;
                else
                        goto start;
        }

        /* Unexpected handshake message (Client Hello, or protocol violation) */
        if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) {
                if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) &&
                    !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
                        S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
                        s->internal->renegotiate = 1;
                        s->internal->new_session = 1;
                }
                i = s->internal->handshake_func(s);
                if (i < 0)
                        return (i);
                if (i == 0) {
                        SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
                        return (-1);
                }

                if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
                        if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
                                /* 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 */
                                ssl_force_want_read(s);
                                return (-1);
                        }
                }
                goto start;
        }

        switch (rr->type) {
        default:
                /*
                 * TLS up to v1.1 just ignores unknown message types:
                 * TLS v1.2 give an unexpected message alert.
                 */
                if (s->version >= TLS1_VERSION &&
                    s->version <= TLS1_1_VERSION) {
                        rr->length = 0;
                        goto start;
                }
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerror(s, 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->internal->in_handshake is set, but that
                 * should not happen when type != rr->type */
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerror(s, 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 (S3I(s)->in_read_app_data &&
                    (S3I(s)->total_renegotiations != 0) &&
                    (((S3I(s)->hs.state & SSL_ST_CONNECT) &&
                    (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
                    (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) ||
                    ((S3I(s)->hs.state & SSL_ST_ACCEPT) &&
                    (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
                    (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
                        S3I(s)->in_read_app_data = 2;
                        return (-1);
                } else {
                        al = SSL_AD_UNEXPECTED_MESSAGE;
                        SSLerror(s, SSL_R_UNEXPECTED_RECORD);
                        goto f_err;
                }
        }
        /* not reached */

f_err:
        ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
        return (-1);
}

int
ssl3_do_change_cipher_spec(SSL *s)
{
        int i;
        const char *sender;
        int slen;

        if (S3I(s)->hs.state & SSL_ST_ACCEPT)
                i = SSL3_CHANGE_CIPHER_SERVER_READ;
        else
                i = SSL3_CHANGE_CIPHER_CLIENT_READ;

        if (S3I(s)->hs.key_block == NULL) {
                if (s->session == NULL || s->session->master_key_length == 0) {
                        /* might happen if dtls1_read_bytes() calls this */
                        SSLerror(s, SSL_R_CCS_RECEIVED_EARLY);
                        return (0);
                }

                s->session->cipher = S3I(s)->hs.new_cipher;
                if (!tls1_setup_key_block(s))
                        return (0);
        }

        if (!tls1_change_cipher_state(s, i))
                return (0);

        /* we have to record the message digest at
         * this point so we can get it before we read
         * the finished message */
        if (S3I(s)->hs.state & SSL_ST_CONNECT) {
                sender = TLS_MD_SERVER_FINISH_CONST;
                slen = TLS_MD_SERVER_FINISH_CONST_SIZE;
        } else {
                sender = TLS_MD_CLIENT_FINISH_CONST;
                slen = TLS_MD_CLIENT_FINISH_CONST_SIZE;
        }

        i = tls1_final_finish_mac(s, sender, slen,
            S3I(s)->tmp.peer_finish_md);
        if (i == 0) {
                SSLerror(s, ERR_R_INTERNAL_ERROR);
                return 0;
        }
        S3I(s)->tmp.peer_finish_md_len = i;

        return (1);
}

int
ssl3_send_alert(SSL *s, int level, int desc)
{
        /* Map tls/ssl alert value to correct one */
        desc = tls1_alert_code(desc);
        if (desc < 0)
                return -1;
        /* If a fatal one, remove from cache */
        if ((level == 2) && (s->session != NULL))
                SSL_CTX_remove_session(s->ctx, s->session);

        s->s3->alert_dispatch = 1;
        s->s3->send_alert[0] = level;
        s->s3->send_alert[1] = desc;
        if (s->s3->wbuf.left == 0) /* data still being written out? */
                return s->method->ssl_dispatch_alert(s);

        /* else data is still being written out, we will get written
         * some time in the future */
        return -1;
}

int
ssl3_dispatch_alert(SSL *s)
{
        int i, j;
        void (*cb)(const SSL *ssl, int type, int val) = NULL;

        s->s3->alert_dispatch = 0;
        i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
        if (i <= 0) {
                s->s3->alert_dispatch = 1;
        } else {
                /* Alert sent to BIO.  If it is important, flush it now.
                 * If the message does not get sent due to non-blocking IO,
                 * we will not worry too much. */
                if (s->s3->send_alert[0] == SSL3_AL_FATAL)
                        (void)BIO_flush(s->wbio);

                if (s->internal->msg_callback)
                        s->internal->msg_callback(1, s->version, SSL3_RT_ALERT,
                            s->s3->send_alert, 2, s, s->internal->msg_callback_arg);

                if (s->internal->info_callback != NULL)
                        cb = s->internal->info_callback;
                else if (s->ctx->internal->info_callback != NULL)
                        cb = s->ctx->internal->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);
}