X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fs3_pkt.c;h=ca5412dc2a4c15dfc7e0baf8f0986b8fd6c2a00c;hp=8b8ecdf8df1c8098c2737a1686282d10eb780be5;hb=fc90e42c8623af13308d8ef7e7ada84af0a36509;hpb=f2d9a32cf47ed8c4e4d025a2258154f3dbe5eca6

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index 8b8ecdf8df..ca5412dc2a 100644
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -55,120 +55,220 @@
  * 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 <stdio.h>
 #include <errno.h>
 #define USE_SOCKETS
+#include "ssl_locl.h"
 #include <openssl/evp.h>
 #include <openssl/buffer.h>
-#include "ssl_locl.h"
+#include <openssl/rand.h>
 
 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
-			 unsigned int len);
-static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
-			      unsigned int len);
+			 unsigned int len, int create_empty_fragment);
 static int ssl3_get_record(SSL *s);
-static int do_compress(SSL *ssl);
-static int do_uncompress(SSL *ssl);
-static int do_change_cipher_spec(SSL *ssl);
-static int ssl3_read_n(SSL *s, int n, int max, int extend)
+
+int ssl3_read_n(SSL *s, int n, int max, int extend)
 	{
-	int i,off,newb;
+	/* 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->packet and s->packet_length.
+	 * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
+	 * [plus s->packet_length bytes if extend == 1].)
+	 */
+	int i,len,left;
+	long align=0;
+	unsigned char *pkt;
+	SSL3_BUFFER *rb;
+
+	if (n <= 0) return n;
 
-	/* if there is stuff still in the buffer from a previous read,
-	 * and there is more than we want, take some. */
-	if (s->s3->rbuf.left >= (int)n)
+	rb    = &(s->s3->rbuf);
+	if (rb->buf == NULL)
+		if (!ssl3_setup_read_buffer(s))
+			return -1;
+
+	left  = rb->left;
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+	align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
+	align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
+
+	if (!extend)
 		{
-		if (extend)
-			s->packet_length+=n;
-		else
+		/* start with empty packet ... */
+		if (left == 0)
+			rb->offset = align;
+		else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
 			{
-			s->packet= &(s->s3->rbuf.buf[s->s3->rbuf.offset]);
-			s->packet_length=n;
+			/* 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->s3->rbuf.left-=n;
-		s->s3->rbuf.offset+=n;
+		s->packet = rb->buf + rb->offset;
+		s->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_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
+		{
+		if (left > 0 && n > left)
+			n = left;
+		}
+
+	/* if there is enough in the buffer from a previous read, take some */
+	if (left >= n)
+		{
+		s->packet_length+=n;
+		rb->left=left-n;
+		rb->offset+=n;
 		return(n);
 		}
 
 	/* else we need to read more data */
-	if (!s->read_ahead) max=n;
-	if (max > SSL3_RT_MAX_PACKET_SIZE)
-		max=SSL3_RT_MAX_PACKET_SIZE;
-
-	/* First check if there is some left or we want to extend */
-	off=0;
-	if (	(s->s3->rbuf.left != 0) ||
-		((s->packet_length != 0) && extend))
+
+	len = s->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->packet != pkt) /* len > 0 */
 		{
-		newb=s->s3->rbuf.left;
-		if (extend)
-			{
-			/* Copy bytes back to the front of the buffer 
-			 * Take the bytes already pointed to by 'packet'
-			 * and take the extra ones on the end. */
-			off=s->packet_length;
-			if (s->packet != s->s3->rbuf.buf)
-				memcpy(s->s3->rbuf.buf,s->packet,newb+off);
-			}
-		else if (s->s3->rbuf.offset != 0)
-			{ /* so the data is not at the start of the buffer */
-			memcpy(s->s3->rbuf.buf,
-				&(s->s3->rbuf.buf[s->s3->rbuf.offset]),newb);
-			s->s3->rbuf.offset=0;
-			}
+		memmove(pkt, s->packet, len+left);
+		s->packet = pkt;
+		rb->offset = len + align;
+		}
 
-		s->s3->rbuf.left=0;
+	if (n > (int)(rb->len - rb->offset)) /* does not happen */
+		{
+		SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
+		return -1;
 		}
-	else
-		newb=0;
 
-	/* So we now have 'newb' bytes at the front of 
-	 * s->s3->rbuf.buf and need to read some more in on the end
-	 * We start reading into the buffer at 's->s3->rbuf.offset'
-	 */
-	s->packet=s->s3->rbuf.buf;
+	if (!s->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 (newb < n)
+	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) */
+
 		clear_sys_error();
 		if (s->rbio != NULL)
 			{
 			s->rwstate=SSL_READING;
-			i=BIO_read(s->rbio,
-				(char *)&(s->s3->rbuf.buf[off+newb]),
-				max-newb);
+			i=BIO_read(s->rbio,pkt+len+left, max-left);
 			}
 		else
 			{
 			SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
-			i= -1;
+			i = -1;
 			}
 
 		if (i <= 0)
 			{
-			s->s3->rbuf.left+=newb;
+			rb->left = left;
+			if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
+			    SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
+				if (len+left == 0)
+					ssl3_release_read_buffer(s);
 			return(i);
 			}
-		newb+=i;
-		}
-
-	/* record used data read */
-	if (newb > n)
-		{
-		s->s3->rbuf.offset=n+off;
-		s->s3->rbuf.left=newb-n;
-		}
-	else
-		{
-		s->s3->rbuf.offset=0;
-		s->s3->rbuf.left=0;
+		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_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
+			{
+			if (n > left)
+				n = left; /* makes the while condition false */
+			}
 		}
 
-	if (extend)
-		s->packet_length+=n;
-	else
-		s->packet_length+=n;
+	/* done reading, now the book-keeping */
+	rb->offset += n;
+	rb->left = left - n;
+	s->packet_length += n;
+	s->rwstate=SSL_NOTHING;
 	return(n);
 	}
 
@@ -176,39 +276,47 @@ static int ssl3_read_n(SSL *s, int n, int max, int extend)
  * It will return <= 0 if more data is needed, normally due to an error
  * or non-blocking IO.
  * When it finishes, one packet has been decoded and can be found in
- * ssl->s3->rrec.type	- is the type of record
- * ssl->s3->rrec.data, 	- data
+ * ssl->s3->rrec.type    - is the type of record
+ * ssl->s3->rrec.data, 	 - data
  * ssl->s3->rrec.length, - number of bytes
  */
+/* used only by ssl3_read_bytes */
 static int ssl3_get_record(SSL *s)
 	{
 	int ssl_major,ssl_minor,al;
-	int n,i,ret= -1;
-	SSL3_BUFFER *rb;
+	int enc_err,n,i,ret= -1;
 	SSL3_RECORD *rr;
 	SSL_SESSION *sess;
 	unsigned char *p;
 	unsigned char md[EVP_MAX_MD_SIZE];
 	short version;
-	unsigned int mac_size;
-	int clear=0,extra;
+	int mac_size;
+	int clear=0;
+	size_t extra;
+	int decryption_failed_or_bad_record_mac = 0;
+	unsigned char *mac = NULL;
 
 	rr= &(s->s3->rrec);
-	rb= &(s->s3->rbuf);
 	sess=s->session;
 
 	if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 		extra=SSL3_RT_MAX_EXTRA;
 	else
 		extra=0;
+	if (extra && !s->s3->init_extra)
+		{
+		/* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
+		 * set after ssl3_setup_buffers() was done */
+		SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
+		return -1;
+		}
 
 again:
 	/* check if we have the header */
 	if (	(s->rstate != SSL_ST_READ_BODY) ||
 		(s->packet_length < SSL3_RT_HEADER_LENGTH)) 
 		{
-		n=ssl3_read_n(s,SSL3_RT_HEADER_LENGTH,
-			SSL3_RT_MAX_PACKET_SIZE,0);
+		n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 		if (n <= 0) return(n); /* error or non-blocking */
 		s->rstate=SSL_ST_READ_BODY;
 
@@ -220,20 +328,19 @@ again:
 		ssl_minor= *(p++);
 		version=(ssl_major<<8)|ssl_minor;
 		n2s(p,rr->length);
+#if 0
+fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
 
 		/* Lets check version */
-		if (s->first_packet)
-			{
-			s->first_packet=0;
-			}
-		else
+		if (!s->first_packet)
 			{
 			if (version != s->version)
 				{
 				SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-				/* Send back error using their
-				 * version number :-) */
-				s->version=version;
+                                if ((s->version & 0xFF00) == (version & 0xFF00))
+                                	/* Send back error using their minor version number :-) */
+					s->version = (unsigned short)version;
 				al=SSL_AD_PROTOCOL_VERSION;
 				goto f_err;
 				}
@@ -245,35 +352,33 @@ again:
 			goto err;
 			}
 
-		if (rr->length > 
-			(unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+		if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 			{
 			al=SSL_AD_RECORD_OVERFLOW;
 			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 			goto f_err;
 			}
 
-		s->rstate=SSL_ST_READ_BODY;
+		/* now s->rstate == SSL_ST_READ_BODY */
 		}
 
-	/* get and decode the data */
-	if (s->rstate == SSL_ST_READ_BODY)
+	/* s->rstate == SSL_ST_READ_BODY, get and decode the data */
+
+	if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 		{
-		if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
-			{
-			i=rr->length;
-			/*-(s->packet_length-SSL3_RT_HEADER_LENGTH); */
-			n=ssl3_read_n(s,i,i,1);
-			if (n <= 0) return(n); /* error or non-blocking io */
-			}
-		s->rstate=SSL_ST_READ_HEADER;
+		/* now s->packet_length == SSL3_RT_HEADER_LENGTH */
+		i=rr->length;
+		n=ssl3_read_n(s,i,i,1);
+		if (n <= 0) return(n); /* error or non-blocking io */
+		/* now n == rr->length,
+		 * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 		}
 
-	/* At this point, we have the data in s->packet and there should be
-	 * s->packet_length bytes, we must not 'overrun' this buffer :-)
-	 * One of the following functions will copy the data from the
-	 * s->packet buffer */
+	s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 
+	/* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
+	 * and we have that many bytes in s->packet
+	 */
 	rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 
 	/* ok, we can now read from 's->packet' data into 'rr'
@@ -283,14 +388,11 @@ again:
 	 * When the data is 'copied' into the rr->data buffer,
 	 * rr->input will be pointed at the new buffer */ 
 
-	/* Set the state for the following operations */
-	s->rstate=SSL_ST_READ_HEADER;
-
 	/* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 	 * rr->length bytes of encrypted compressed stuff. */
 
-	/* check is not needed I belive */
-	if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
+	/* check is not needed I believe */
+	if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 		{
 		al=SSL_AD_RECORD_OVERFLOW;
 		SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
@@ -300,61 +402,95 @@ again:
 	/* decrypt in place in 'rr->input' */
 	rr->data=rr->input;
 
-	if (!s->method->ssl3_enc->enc(s,0))
+	enc_err = s->method->ssl3_enc->enc(s,0);
+	if (enc_err <= 0)
 		{
-		al=SSL_AD_DECRYPT_ERROR;
-		goto f_err;
+		if (enc_err == 0)
+			/* SSLerr() and ssl3_send_alert() have been called */
+			goto err;
+
+		/* Otherwise enc_err == -1, which indicates bad padding
+		 * (rec->length has not been changed in this case).
+		 * To minimize information leaked via timing, we will perform
+		 * the MAC computation anyway. */
+		decryption_failed_or_bad_record_mac = 1;
 		}
+
 #ifdef TLS_DEBUG
 printf("dec %d\n",rr->length);
 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 printf("\n");
 #endif
+
 	/* r->length is now the compressed data plus mac */
 	if (	(sess == NULL) ||
 		(s->enc_read_ctx == NULL) ||
-		(s->read_hash == NULL))
+		(EVP_MD_CTX_md(s->read_hash) == NULL))
 		clear=1;
 
 	if (!clear)
 		{
-		mac_size=EVP_MD_size(s->read_hash);
+		/* !clear => s->read_hash != NULL => mac_size != -1 */
+		mac_size=EVP_MD_CTX_size(s->read_hash);
+		OPENSSL_assert(mac_size >= 0);
 
 		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 			{
+#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 			al=SSL_AD_RECORD_OVERFLOW;
 			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 			goto f_err;
+#else
+			decryption_failed_or_bad_record_mac = 1;
+#endif			
+			}
+		/* check the MAC for rr->input (it's in mac_size bytes at the tail) */
+		if (rr->length >= (unsigned int)mac_size)
+			{
+			rr->length -= mac_size;
+			mac = &rr->data[rr->length];
 			}
-		/* check MAC for rr->input' */
-		if (rr->length < mac_size)
+		else
 			{
+			/* record (minus padding) is too short to contain a MAC */
+#if 0 /* OK only for stream ciphers */
 			al=SSL_AD_DECODE_ERROR;
 			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 			goto f_err;
+#else
+			decryption_failed_or_bad_record_mac = 1;
+			rr->length = 0;
+#endif
 			}
-		rr->length-=mac_size;
 		i=s->method->ssl3_enc->mac(s,md,0);
-		if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+		if (i < 0 || mac == NULL || memcmp(md, mac, (size_t)mac_size) != 0)
 			{
-			al=SSL_AD_BAD_RECORD_MAC;
-			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_MAC_DECODE);
-			ret= -1;
-			goto f_err;
+			decryption_failed_or_bad_record_mac = 1;
 			}
 		}
 
+	if (decryption_failed_or_bad_record_mac)
+		{
+		/* 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 occured -- this
+		 * might become visible to an attacker (e.g. via a logfile) */
+		al=SSL_AD_BAD_RECORD_MAC;
+		SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
+		goto f_err;
+		}
+
 	/* r->length is now just compressed */
 	if (s->expand != NULL)
 		{
-		if (rr->length > 
-			(unsigned int)SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
+		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 			{
 			al=SSL_AD_RECORD_OVERFLOW;
 			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 			goto f_err;
 			}
-		if (!do_uncompress(s))
+		if (!ssl3_do_uncompress(s))
 			{
 			al=SSL_AD_DECOMPRESSION_FAILURE;
 			SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
@@ -362,7 +498,7 @@ printf("\n");
 			}
 		}
 
-	if (rr->length > (unsigned int)SSL3_RT_MAX_PLAIN_LENGTH+extra)
+	if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 		{
 		al=SSL_AD_RECORD_OVERFLOW;
 		SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
@@ -384,15 +520,21 @@ printf("\n");
 	/* just read a 0 length packet */
 	if (rr->length == 0) goto again;
 
+#if 0
+fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
+#endif
+
 	return(1);
+
 f_err:
 	ssl3_send_alert(s,SSL3_AL_FATAL,al);
 err:
 	return(ret);
 	}
 
-static int do_uncompress(SSL *ssl)
+int ssl3_do_uncompress(SSL *ssl)
 	{
+#ifndef OPENSSL_NO_COMP
 	int i;
 	SSL3_RECORD *rr;
 
@@ -404,12 +546,13 @@ static int do_uncompress(SSL *ssl)
 	else
 		rr->length=i;
 	rr->data=rr->comp;
-
+#endif
 	return(1);
 	}
 
-static int do_compress(SSL *ssl)
+int ssl3_do_compress(SSL *ssl)
 	{
+#ifndef OPENSSL_NO_COMP
 	int i;
 	SSL3_RECORD *wr;
 
@@ -423,15 +566,16 @@ static int do_compress(SSL *ssl)
 		wr->length=i;
 
 	wr->input=wr->data;
+#endif
 	return(1);
 	}
 
-/* Call this to write data
+/* 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)
+int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 	{
-	const unsigned char *buf=_buf;
+	const unsigned char *buf=buf_;
 	unsigned int tot,n,nw;
 	int i;
 
@@ -446,33 +590,34 @@ int ssl3_write_bytes(SSL *s, int type, const void *_buf, int len)
 		if (i == 0)
 			{
 			SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
-			return(-1);
+			return -1;
 			}
 		}
 
 	n=(len-tot);
 	for (;;)
 		{
-		if (n > SSL3_RT_MAX_PLAIN_LENGTH)
-			nw=SSL3_RT_MAX_PLAIN_LENGTH;
+		if (n > s->max_send_fragment)
+			nw=s->max_send_fragment;
 		else
 			nw=n;
-			
-		i=do_ssl3_write(s,type,&(buf[tot]),nw);
+
+		i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 		if (i <= 0)
 			{
 			s->s3->wnum=tot;
-			return(i);
+			return i;
 			}
 
-		if (type == SSL3_RT_HANDSHAKE)
-			ssl3_finish_mac(s,&(buf[tot]),i);
-
 		if ((i == (int)n) ||
 			(type == SSL3_RT_APPLICATION_DATA &&
 			 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 			{
-			return(tot+i);
+			/* next chunk of data should get another prepended empty fragment
+			 * in ciphersuites with known-IV weakness: */
+			s->s3->empty_fragment_done = 0;
+			
+			return tot+i;
 			}
 
 		n-=i;
@@ -481,59 +626,146 @@ int ssl3_write_bytes(SSL *s, int type, const void *_buf, int len)
 	}
 
 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
-			 unsigned int len)
+			 unsigned int len, int create_empty_fragment)
 	{
 	unsigned char *p,*plen;
 	int i,mac_size,clear=0;
+	int prefix_len=0;
+	int eivlen;
+	long align=0;
 	SSL3_RECORD *wr;
-	SSL3_BUFFER *wb;
+	SSL3_BUFFER *wb=&(s->s3->wbuf);
 	SSL_SESSION *sess;
 
-	/* first check is there is a SSL3_RECORD still being written
+ 	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 (s->s3->wbuf.left != 0)
+	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=ssl3_dispatch_alert(s);
+		i=s->method->ssl_dispatch_alert(s);
 		if (i <= 0)
 			return(i);
 		/* if it went, fall through and send more stuff */
 		}
 
-	if (len <= 0) return(len);
-	
+	if (len == 0 && !create_empty_fragment)
+		return 0;
+
 	wr= &(s->s3->wrec);
-	wb= &(s->s3->wbuf);
 	sess=s->session;
 
 	if (	(sess == NULL) ||
 		(s->enc_write_ctx == NULL) ||
-		(s->write_hash == NULL))
+		(EVP_MD_CTX_md(s->write_hash) == NULL))
+		{
+#if 1
+		clear=s->enc_write_ctx?0:1;	/* must be AEAD cipher */
+#else
 		clear=1;
-
-	if (clear)
+#endif
 		mac_size=0;
+		}
 	else
-		mac_size=EVP_MD_size(s->write_hash);
+		{
+		mac_size=EVP_MD_CTX_size(s->write_hash);
+		if (mac_size < 0)
+			goto err;
+		}
+
+	/* 'create_empty_fragment' is true only when this function calls itself */
+	if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
+		{
+		/* countermeasure against known-IV weakness in CBC ciphersuites
+		 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 
-	p=wb->buf;
+		if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
+			{
+			/* recursive function call with 'create_empty_fragment' set;
+			 * this prepares and buffers the data for an empty fragment
+			 * (these 'prefix_len' bytes are sent out later
+			 * together with the actual payload) */
+			prefix_len = 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 */
+				SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
+				goto err;
+				}
+			}
+		
+		s->s3->empty_fragment_done = 1;
+		}
+
+	if (create_empty_fragment)
+		{
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+		/* 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 = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
+		align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
+		p = wb->buf + align;
+		wb->offset  = align;
+		}
+	else if (prefix_len)
+		{
+		p = wb->buf + wb->offset + prefix_len;
+		}
+	else
+		{
+#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
+		align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
+		align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
+#endif
+		p = wb->buf + align;
+		wb->offset  = align;
+		}
 
 	/* write the header */
+
 	*(p++)=type&0xff;
 	wr->type=type;
 
 	*(p++)=(s->version>>8);
 	*(p++)=s->version&0xff;
-	
-	/* record where we are to write out packet length */
+
+	/* field where we are to write out packet length */
 	plen=p; 
 	p+=2;
-	
+	/* Explicit IV length, block ciphers and TLS version 1.1 or later */
+	if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
+		{
+		int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
+		if (mode == EVP_CIPH_CBC_MODE)
+			{
+			eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
+			if (eivlen <= 1)
+				eivlen = 0;
+			}
+		/* Need explicit part of IV for GCM mode */
+		else if (mode == EVP_CIPH_GCM_MODE)
+			eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
+		else
+			eivlen = 0;
+		}
+	else 
+		eivlen = 0;
+
 	/* lets setup the record stuff. */
-	wr->data=p;
+	wr->data=p + eivlen;
 	wr->length=(int)len;
 	wr->input=(unsigned char *)buf;
 
@@ -543,7 +775,7 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 	/* first we compress */
 	if (s->compress != NULL)
 		{
-		if (!do_compress(s))
+		if (!ssl3_do_compress(s))
 			{
 			SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 			goto err;
@@ -561,10 +793,19 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 
 	if (mac_size != 0)
 		{
-		s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
+		if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
+			goto err;
 		wr->length+=mac_size;
-		wr->input=p;
-		wr->data=p;
+		}
+
+	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 */
@@ -579,26 +820,35 @@ static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 	wr->type=type; /* not needed but helps for debugging */
 	wr->length+=SSL3_RT_HEADER_LENGTH;
 
-	/* Now lets setup wb */
-	wb->left=wr->length;
-	wb->offset=0;
+	if (create_empty_fragment)
+		{
+		/* we are in a recursive call;
+		 * just return the length, don't write out anything here
+		 */
+		return wr->length;
+		}
 
+	/* now let's set up wb */
+	wb->left = prefix_len + wr->length;
+
+	/* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 	s->s3->wpend_tot=len;
 	s->s3->wpend_buf=buf;
 	s->s3->wpend_type=type;
 	s->s3->wpend_ret=len;
 
 	/* we now just need to write the buffer */
-	return(ssl3_write_pending(s,type,buf,len));
+	return ssl3_write_pending(s,type,buf,len);
 err:
-	return(-1);
+	return -1;
 	}
 
 /* if s->s3->wbuf.left != 0, we need to call this */
-static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
-			      unsigned int len)
+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 ((s->s3->wpend_tot > (int)len)
@@ -617,40 +867,109 @@ static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 			{
 			s->rwstate=SSL_WRITING;
 			i=BIO_write(s->wbio,
-				(char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
-				(unsigned int)s->s3->wbuf.left);
+				(char *)&(wb->buf[wb->offset]),
+				(unsigned int)wb->left);
 			}
 		else
 			{
 			SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 			i= -1;
 			}
-		if (i == s->s3->wbuf.left)
+		if (i == wb->left)
 			{
-			s->s3->wbuf.left=0;
+			wb->left=0;
+			wb->offset+=i;
+			if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
+			    SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
+				ssl3_release_write_buffer(s);
 			s->rwstate=SSL_NOTHING;
 			return(s->s3->wpend_ret);
 			}
-		else if (i <= 0)
+		else if (i <= 0) {
+			if (s->version == DTLS1_VERSION ||
+			    s->version == DTLS1_BAD_VER) {
+				/* For DTLS, just drop it. That's kind of the whole
+				   point in using a datagram service */
+				wb->left = 0;
+			}
 			return(i);
-		s->s3->wbuf.offset+=i;
-		s->s3->wbuf.left-=i;
+		}
+		wb->offset+=i;
+		wb->left-=i;
 		}
 	}
 
-int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len)
+/* 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)
 	{
-	int al,i,j,n,ret;
+	int al,i,j,ret;
+	unsigned int n;
 	SSL3_RECORD *rr;
-	void (*cb)()=NULL;
-	BIO *bio;
+	void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 
-	if (s->s3->rbuf.buf == NULL) /* Not initialize yet */
-		if (!ssl3_setup_buffers(s))
+	if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
+		if (!ssl3_setup_read_buffer(s))
 			return(-1);
 
+	if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
+	    (peek && (type != SSL3_RT_APPLICATION_DATA)))
+		{
+		SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
+		return -1;
+		}
+
+	if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
+		/* (partially) satisfy request from storage */
+		{
+		unsigned char *src = s->s3->handshake_fragment;
+		unsigned char *dst = buf;
+		unsigned int k;
+
+		/* peek == 0 */
+		n = 0;
+		while ((len > 0) && (s->s3->handshake_fragment_len > 0))
+			{
+			*dst++ = *src++;
+			len--; s->s3->handshake_fragment_len--;
+			n++;
+			}
+		/* move any remaining fragment bytes: */
+		for (k = 0; k < s->s3->handshake_fragment_len; k++)
+			s->s3->handshake_fragment[k] = *src++;
+		return n;
+	}
+
+	/* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
+
 	if (!s->in_handshake && SSL_in_init(s))
 		{
+		/* type == SSL3_RT_APPLICATION_DATA */
 		i=s->handshake_func(s);
 		if (i < 0) return(i);
 		if (i == 0)
@@ -662,13 +981,13 @@ int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len)
 start:
 	s->rwstate=SSL_NOTHING;
 
-	/* s->s3->rrec.type	- is the type of record
-	 * s->s3->rrec.data, 	- data
-	 * s->s3->rrec.off, 	- ofset into 'data' for next read
-	 * s->s3->rrec.length,	- number of bytes. */
-	rr= &(s->s3->rrec);
+	/* s->s3->rrec.type	    - is the type of record
+	 * s->s3->rrec.data,    - data
+	 * s->s3->rrec.off,     - offset into 'data' for next read
+	 * s->s3->rrec.length,  - number of bytes. */
+	rr = &(s->s3->rrec);
 
-	/* get new packet */
+	/* get new packet if necessary */
 	if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 		{
 		ret=ssl3_get_record(s);
@@ -677,14 +996,17 @@ start:
 
 	/* we now have a packet which can be read and processed */
 
-	if (s->s3->change_cipher_spec && (rr->type != SSL3_RT_HANDSHAKE))
+	if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
+	                               * reset by ssl3_get_finished */
+		&& (rr->type != SSL3_RT_HANDSHAKE))
 		{
 		al=SSL_AD_UNEXPECTED_MESSAGE;
 		SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
-		goto err;
+		goto f_err;
 		}
 
-	/* If the other end has shutdown, throw anything we read away */
+	/* If the other end has shut down, throw anything we read away
+	 * (even in 'peek' mode) */
 	if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 		{
 		rr->length=0;
@@ -692,19 +1014,122 @@ start:
 		return(0);
 		}
 
-	/* Check for an incoming 'Client Request' message */
-	if ((rr->type == SSL3_RT_HANDSHAKE) && (rr->length == 4) &&
-		(rr->data[0] == SSL3_MT_CLIENT_REQUEST) &&
+
+	if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
+		{
+		/* make sure that we are not getting application data when we
+		 * are doing a handshake for the first time */
+		if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
+			(s->enc_read_ctx == NULL))
+			{
+			al=SSL_AD_UNEXPECTED_MESSAGE;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
+			goto f_err;
+			}
+
+		if (len <= 0) return(len);
+
+		if ((unsigned int)len > rr->length)
+			n = rr->length;
+		else
+			n = (unsigned int)len;
+
+		memcpy(buf,&(rr->data[rr->off]),n);
+		if (!peek)
+			{
+			rr->length-=n;
+			rr->off+=n;
+			if (rr->length == 0)
+				{
+				s->rstate=SSL_ST_READ_HEADER;
+				rr->off=0;
+				if (s->mode & SSL_MODE_RELEASE_BUFFERS)
+					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 s->s3->handshake_fragment;
+			dest = s->s3->handshake_fragment;
+			dest_len = &s->s3->handshake_fragment_len;
+			}
+		else if (rr->type == SSL3_RT_ALERT)
+			{
+			dest_maxlen = sizeof s->s3->alert_fragment;
+			dest = s->s3->alert_fragment;
+			dest_len = &s->s3->alert_fragment_len;
+			}
+#ifndef OPENSSL_NO_HEARTBEATS
+		else if (rr->type == TLS1_RT_HEARTBEAT)
+			{
+			tls1_process_heartbeat(s);
+
+			/* Exit and notify application to read again */
+			rr->length = 0;
+			s->rwstate=SSL_READING;
+			BIO_clear_retry_flags(SSL_get_rbio(s));
+			BIO_set_retry_read(SSL_get_rbio(s));
+			return(-1);
+			}
+#endif
+
+		if (dest_maxlen > 0)
+			{
+			n = dest_maxlen - *dest_len; /* available space in 'dest' */
+			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 */
+			}
+		}
+
+	/* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
+	 * s->s3->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) &&
+		(s->s3->handshake_fragment_len >= 4) &&
+		(s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 		(s->session != NULL) && (s->session->cipher != NULL))
 		{
-		if ((rr->data[1] != 0) || (rr->data[2] != 0) ||
-			(rr->data[3] != 0))
+		s->s3->handshake_fragment_len = 0;
+
+		if ((s->s3->handshake_fragment[1] != 0) ||
+			(s->s3->handshake_fragment[2] != 0) ||
+			(s->s3->handshake_fragment[3] != 0))
 			{
 			al=SSL_AD_DECODE_ERROR;
-			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CLIENT_REQUEST);
-			goto err;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
+			goto f_err;
 			}
 
+		if (s->msg_callback)
+			s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
+
 		if (SSL_is_init_finished(s) &&
 			!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 			!s->s3->renegotiate)
@@ -712,233 +1137,280 @@ start:
 			ssl3_renegotiate(s);
 			if (ssl3_renegotiate_check(s))
 				{
-				n=s->handshake_func(s);
-				if (n < 0) return(n);
-				if (n == 0)
+				i=s->handshake_func(s);
+				if (i < 0) return(i);
+				if (i == 0)
 					{
 					SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 					return(-1);
 					}
+
+				if (!(s->mode & SSL_MODE_AUTO_RETRY))
+					{
+					if (s->s3->rbuf.left == 0) /* no read-ahead left? */
+						{
+						BIO *bio;
+						/* In the case where we try to read application data,
+						 * but we trigger an SSL handshake, we return -1 with
+						 * the retry option set.  Otherwise renegotiation may
+						 * cause nasty problems in the blocking world */
+						s->rwstate=SSL_READING;
+						bio=SSL_get_rbio(s);
+						BIO_clear_retry_flags(bio);
+						BIO_set_retry_read(bio);
+						return(-1);
+						}
+					}
 				}
 			}
-		rr->length=0;
-/* ZZZ */	goto start;
+		/* we either finished a handshake or ignored the request,
+		 * now try again to obtain the (application) data we were asked for */
+		goto start;
 		}
-
-	/* if it is not the type we want, or we have shutdown and want
-	 * the peer shutdown */
-	if ((rr->type != type) || (s->shutdown & SSL_SENT_SHUTDOWN))
+	/* 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) &&
+    		!s->s3->send_connection_binding &&
+		(s->version > SSL3_VERSION) &&
+		(s->s3->handshake_fragment_len >= 4) &&
+		(s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
+		(s->session != NULL) && (s->session->cipher != NULL) &&
+		!(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
+		
 		{
-		if (rr->type == SSL3_RT_ALERT)
-			{
-			if ((rr->length != 2) || (rr->off != 0))
-				{
-				al=SSL_AD_DECODE_ERROR;
-				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_ALERT_RECORD);
-				goto f_err;
-				}
+		/*s->s3->handshake_fragment_len = 0;*/
+		rr->length = 0;
+		ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
+		goto start;
+		}
+	if (s->s3->alert_fragment_len >= 2)
+		{
+		int alert_level = s->s3->alert_fragment[0];
+		int alert_descr = s->s3->alert_fragment[1];
 
-			i=rr->data[0];
-			n=rr->data[1];
+		s->s3->alert_fragment_len = 0;
 
-			/* clear from buffer */
-			rr->length=0;
+		if (s->msg_callback)
+			s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
 
-			if (s->info_callback != NULL)
-				cb=s->info_callback;
-			else if (s->ctx->info_callback != NULL)
-				cb=s->ctx->info_callback;
+		if (s->info_callback != NULL)
+			cb=s->info_callback;
+		else if (s->ctx->info_callback != NULL)
+			cb=s->ctx->info_callback;
 
-			if (cb != NULL)
-				{
-				j=(i<<8)|n;
-				cb(s,SSL_CB_READ_ALERT,j);
-				}
+		if (cb != NULL)
+			{
+			j = (alert_level << 8) | alert_descr;
+			cb(s, SSL_CB_READ_ALERT, j);
+			}
 
-			if (i == 1)
-				{
-				s->s3->warn_alert=n;
-				if (n == SSL_AD_CLOSE_NOTIFY)
-					{
-					s->shutdown|=SSL_RECEIVED_SHUTDOWN;
-					return(0);
-					}
-				}
-			else if (i == 2)
+		if (alert_level == 1) /* warning */
+			{
+			s->s3->warn_alert = alert_descr;
+			if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 				{
-				char tmp[16];
-
-				s->rwstate=SSL_NOTHING;
-				s->s3->fatal_alert=n;
-				SSLerr(SSL_F_SSL3_READ_BYTES,
-					SSL_AD_REASON_OFFSET+n);
-				sprintf(tmp,"%d",n);
-				ERR_add_error_data(2,"SSL alert number ",tmp);
-				s->shutdown|=SSL_RECEIVED_SHUTDOWN;
-				SSL_CTX_remove_session(s->ctx,s->session);
+				s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 				return(0);
 				}
-			else
+			/* 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_ILLEGAL_PARAMETER;
-				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
+				al = SSL_AD_HANDSHAKE_FAILURE;
+				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
 				goto f_err;
 				}
-
-			rr->length=0;
-			goto start;
+#ifdef SSL_AD_MISSING_SRP_USERNAME
+			else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
+				return(0);
+#endif
 			}
-
-		if (s->shutdown & SSL_SENT_SHUTDOWN)
+		else if (alert_level == 2) /* fatal */
 			{
+			char tmp[16];
+
 			s->rwstate=SSL_NOTHING;
-			rr->length=0;
+			s->s3->fatal_alert = alert_descr;
+			SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
+			BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
+			ERR_add_error_data(2,"SSL alert number ",tmp);
+			s->shutdown|=SSL_RECEIVED_SHUTDOWN;
+			SSL_CTX_remove_session(s->ctx,s->session);
 			return(0);
 			}
-
-		if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
+		else
 			{
-			if (	(rr->length != 1) || (rr->off != 0) ||
-				(rr->data[0] != SSL3_MT_CCS))
-				{
-				i=SSL_AD_ILLEGAL_PARAMETER;
-				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
-				goto err;
-				}
+			al=SSL_AD_ILLEGAL_PARAMETER;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
+			goto f_err;
+			}
 
-			rr->length=0;
-			s->s3->change_cipher_spec=1;
-			if (!do_change_cipher_spec(s))
-				goto err;
-			else
-				goto start;
+		goto start;
+		}
+
+	if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
+		{
+		s->rwstate=SSL_NOTHING;
+		rr->length=0;
+		return(0);
+		}
+
+	if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
+		{
+		/* '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;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
+			goto f_err;
 			}
 
-		/* else we have a handshake */
-		if ((rr->type == SSL3_RT_HANDSHAKE) &&
-			!s->in_handshake)
+		/* Check we have a cipher to change to */
+		if (s->s3->tmp.new_cipher == NULL)
 			{
-			if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
-				!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
-				{
-				s->state=SSL_ST_BEFORE|(s->server)
-						?SSL_ST_ACCEPT
-						:SSL_ST_CONNECT;
-				s->new_session=1;
-				}
-			n=s->handshake_func(s);
-			if (n < 0) return(n);
-			if (n == 0)
-				{
-				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
-				return(-1);
-				}
+			al=SSL_AD_UNEXPECTED_MESSAGE;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
+			goto f_err;
+			}
 
-			/* In the case where we try to read application data
-			 * the first time, but we trigger an SSL handshake, we
-			 * return -1 with the retry option set.  I do this
-			 * otherwise renegotiation can cause nasty problems 
-			 * in the non-blocking world */
+		rr->length=0;
 
-			s->rwstate=SSL_READING;
-			bio=SSL_get_rbio(s);
-			BIO_clear_retry_flags(bio);
-			BIO_set_retry_read(bio);
+		if (s->msg_callback)
+			s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
+
+		s->s3->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 ((s->s3->handshake_fragment_len >= 4) &&	!s->in_handshake)
+		{
+		if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
+			!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
+			{
+#if 0 /* worked only because C operator preferences are not as expected (and
+       * because this is not really needed for clients except for detecting
+       * protocol violations): */
+			s->state=SSL_ST_BEFORE|(s->server)
+				?SSL_ST_ACCEPT
+				:SSL_ST_CONNECT;
+#else
+			s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
+#endif
+			s->renegotiate=1;
+			s->new_session=1;
+			}
+		i=s->handshake_func(s);
+		if (i < 0) return(i);
+		if (i == 0)
+			{
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 			return(-1);
 			}
 
-		switch (rr->type)
+		if (!(s->mode & SSL_MODE_AUTO_RETRY))
 			{
-		default:
-#ifndef NO_TLS
-			/* TLS just ignores unknown message types */
-			if (s->version == TLS1_VERSION)
+			if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 				{
-				goto start;
-				}
-#endif
-		case SSL3_RT_CHANGE_CIPHER_SPEC:
-		case SSL3_RT_ALERT:
-		case SSL3_RT_HANDSHAKE:
-			al=SSL_AD_UNEXPECTED_MESSAGE;
-			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
-			goto f_err;
-		case SSL3_RT_APPLICATION_DATA:
-			/* At this point, we were expecting something else,
-			 * but have application data.  What we do is set the
-			 * error, and return -1.  On the way out, if the
-			 * library was running inside ssl3_read() and it makes
-			 * sense to read application data at this point, we
-			 * will indulge it.  This will mostly happen during
-			 * session renegotiation.
-			 */
-			if (s->s3->in_read_app_data &&
-				(s->s3->total_renegotiations != 0) &&
-				((
-				  (s->state & SSL_ST_CONNECT) &&
-				  (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
-				  (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
-				 ) || (
-				  (s->state & SSL_ST_ACCEPT) &&
-				  (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
-				  (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
-				 )
-				))
-				{
-				s->s3->in_read_app_data=0;
+				BIO *bio;
+				/* In the case where we try to read application data,
+				 * but we trigger an SSL handshake, we return -1 with
+				 * the retry option set.  Otherwise renegotiation may
+				 * cause nasty problems in the blocking world */
+				s->rwstate=SSL_READING;
+				bio=SSL_get_rbio(s);
+				BIO_clear_retry_flags(bio);
+				BIO_set_retry_read(bio);
 				return(-1);
 				}
-			else
-				{
-				al=SSL_AD_UNEXPECTED_MESSAGE;
-				SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
-				goto f_err;
-				}
 			}
+		goto start;
 		}
 
-	/* 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))
+	switch (rr->type)
 		{
+	default:
+#ifndef OPENSSL_NO_TLS
+		/* 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;
+			}
+#endif
 		al=SSL_AD_UNEXPECTED_MESSAGE;
-		SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
+		SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 		goto f_err;
+	case SSL3_RT_CHANGE_CIPHER_SPEC:
+	case SSL3_RT_ALERT:
+	case SSL3_RT_HANDSHAKE:
+		/* we already handled all of these, with the possible exception
+		 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
+		 * should not happen when type != rr->type */
+		al=SSL_AD_UNEXPECTED_MESSAGE;
+		SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
+		goto f_err;
+	case SSL3_RT_APPLICATION_DATA:
+		/* At this point, we were expecting handshake data,
+		 * but have application data.  If the library was
+		 * running inside ssl3_read() (i.e. in_read_app_data
+		 * is set) and it makes sense to read application data
+		 * at this point (session renegotiation not yet started),
+		 * we will indulge it.
+		 */
+		if (s->s3->in_read_app_data &&
+			(s->s3->total_renegotiations != 0) &&
+			((
+				(s->state & SSL_ST_CONNECT) &&
+				(s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
+				(s->state <= SSL3_ST_CR_SRVR_HELLO_A)
+				) || (
+					(s->state & SSL_ST_ACCEPT) &&
+					(s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
+					(s->state >= SSL3_ST_SR_CLNT_HELLO_A)
+					)
+				))
+			{
+			s->s3->in_read_app_data=2;
+			return(-1);
+			}
+		else
+			{
+			al=SSL_AD_UNEXPECTED_MESSAGE;
+			SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
+			goto f_err;
+			}
 		}
+	/* not reached */
 
-	if (len <= 0) return(len);
-
-	if ((unsigned int)len > rr->length)
-		n=rr->length;
-	else
-		n=len;
-
-	memcpy(buf,&(rr->data[rr->off]),(unsigned int)n);
-	rr->length-=n;
-	rr->off+=n;
-	if (rr->length <= 0)
-		{
-		s->rstate=SSL_ST_READ_HEADER;
-		rr->off=0;
-		}
-
-	if (type == SSL3_RT_HANDSHAKE)
-		ssl3_finish_mac(s,buf,n);
-	return(n);
 f_err:
 	ssl3_send_alert(s,SSL3_AL_FATAL,al);
 err:
 	return(-1);
 	}
 
-static int do_change_cipher_spec(SSL *s)
+int ssl3_do_change_cipher_spec(SSL *s)
 	{
 	int i;
 	const char *sender;
 	int slen;
-	unsigned char *finish_md;
-	int *finish_md_len;
 
 	if (s->state & SSL_ST_ACCEPT)
 		i=SSL3_CHANGE_CIPHER_SERVER_READ;
@@ -947,6 +1419,13 @@ static int do_change_cipher_spec(SSL *s)
 
 	if (s->s3->tmp.key_block == NULL)
 		{
+		if (s->session == NULL) 
+			{
+			/* might happen if dtls1_read_bytes() calls this */
+			SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
+			return (0);
+			}
+
 		s->session->cipher=s->s3->tmp.new_cipher;
 		if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
 		}
@@ -961,44 +1440,26 @@ static int do_change_cipher_spec(SSL *s)
 		{
 		sender=s->method->ssl3_enc->server_finished_label;
 		slen=s->method->ssl3_enc->server_finished_label_len;
-		finish_md = s->s3->tmp.server_finish_md;
-		finish_md_len = &s->s3->tmp.server_finish_md_len;
 		}
 	else
 		{
 		sender=s->method->ssl3_enc->client_finished_label;
 		slen=s->method->ssl3_enc->client_finished_label_len;
-		finish_md = s->s3->tmp.client_finish_md;
-		finish_md_len = &s->s3->tmp.client_finish_md_len;
 		}
 
-	*finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
-		&(s->s3->finish_dgst1),
-		&(s->s3->finish_dgst2),
-		sender,slen,finish_md);
+	s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
+		sender,slen,s->s3->tmp.peer_finish_md);
 
 	return(1);
 	}
 
-int ssl3_do_write(SSL *s, int type)
-	{
-	int ret;
-
-	ret=ssl3_write_bytes(s,type,&s->init_buf->data[s->init_off],
-			     s->init_num);
-	if (ret == s->init_num)
-		return(1);
-	if (ret < 0) return(-1);
-	s->init_off+=ret;
-	s->init_num-=ret;
-	return(0);
-	}
-
-void ssl3_send_alert(SSL *s, int level, int desc)
+int ssl3_send_alert(SSL *s, int level, int desc)
 	{
 	/* Map tls/ssl alert value to correct one */
 	desc=s->method->ssl3_enc->alert_value(desc);
-	if (desc < 0) return;
+	if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
+		desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
+	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);
@@ -1006,36 +1467,40 @@ void ssl3_send_alert(SSL *s, int level, int desc)
 	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 */
-		ssl3_dispatch_alert(s);
+	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)()=NULL;
+	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);
+	i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
 	if (i <= 0)
 		{
 		s->s3->alert_dispatch=1;
 		}
 	else
 		{
-		/* If it is important, send it now.  If the message
-		 * does not get sent due to non-blocking IO, we will
-		 * not worry too much. */
+		/* 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->msg_callback)
+			s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
+
 		if (s->info_callback != NULL)
 			cb=s->info_callback;
 		else if (s->ctx->info_callback != NULL)
 			cb=s->ctx->info_callback;
-		
+
 		if (cb != NULL)
 			{
 			j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
@@ -1044,4 +1509,3 @@ int ssl3_dispatch_alert(SSL *s)
 		}
 	return(i);
 	}
-