path: root/ssl/ssl3.h

/* ssl/ssl3.h */
/* 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECC cipher suite support in OpenSSL originally developed by 
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

#ifndef HEADER_SSL3_H 
#define HEADER_SSL3_H 

#ifndef OPENSSL_NO_COMP
#include <openssl/comp.h>
#endif
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/ssl.h>

#ifdef  __cplusplus
extern "C" {
#endif

/* Signalling cipher suite value from RFC 5746
 * (TLS_EMPTY_RENEGOTIATION_INFO_SCSV) */
#define SSL3_CK_SCSV				0x030000FF

/* Signalling cipher suite value from draft-ietf-tls-downgrade-scsv-00
 * (TLS_FALLBACK_SCSV) */
#define SSL3_CK_FALLBACK_SCSV			0x03005600

#define SSL3_CK_RSA_NULL_MD5			0x03000001
#define SSL3_CK_RSA_NULL_SHA			0x03000002
#define SSL3_CK_RSA_RC4_40_MD5 			0x03000003
#define SSL3_CK_RSA_RC4_128_MD5			0x03000004
#define SSL3_CK_RSA_RC4_128_SHA			0x03000005
#define SSL3_CK_RSA_RC2_40_MD5			0x03000006
#define SSL3_CK_RSA_IDEA_128_SHA		0x03000007
#define SSL3_CK_RSA_DES_40_CBC_SHA		0x03000008
#define SSL3_CK_RSA_DES_64_CBC_SHA		0x03000009
#define SSL3_CK_RSA_DES_192_CBC3_SHA		0x0300000A

#define SSL3_CK_DH_DSS_DES_40_CBC_SHA		0x0300000B
#define SSL3_CK_DH_DSS_DES_64_CBC_SHA		0x0300000C
#define SSL3_CK_DH_DSS_DES_192_CBC3_SHA 	0x0300000D
#define SSL3_CK_DH_RSA_DES_40_CBC_SHA		0x0300000E
#define SSL3_CK_DH_RSA_DES_64_CBC_SHA		0x0300000F
#define SSL3_CK_DH_RSA_DES_192_CBC3_SHA 	0x03000010

#define SSL3_CK_EDH_DSS_DES_40_CBC_SHA		0x03000011
#define SSL3_CK_DHE_DSS_DES_40_CBC_SHA          SSL3_CK_EDH_DSS_DES_40_CBC_SHA
#define SSL3_CK_EDH_DSS_DES_64_CBC_SHA		0x03000012
#define SSL3_CK_DHE_DSS_DES_64_CBC_SHA		SSL3_CK_EDH_DSS_DES_64_CBC_SHA
#define SSL3_CK_EDH_DSS_DES_192_CBC3_SHA	0x03000013
#define SSL3_CK_DHE_DSS_DES_192_CBC3_SHA	SSL3_CK_EDH_DSS_DES_192_CBC3_SHA
#define SSL3_CK_EDH_RSA_DES_40_CBC_SHA		0x03000014
#define SSL3_CK_DHE_RSA_DES_40_CBC_SHA		SSL3_CK_EDH_RSA_DES_40_CBC_SHA
#define SSL3_CK_EDH_RSA_DES_64_CBC_SHA		0x03000015
#define SSL3_CK_DHE_RSA_DES_64_CBC_SHA		SSL3_CK_EDH_RSA_DES_64_CBC_SHA
#define SSL3_CK_EDH_RSA_DES_192_CBC3_SHA	0x03000016
#define SSL3_CK_DHE_RSA_DES_192_CBC3_SHA	SSL3_CK_EDH_RSA_DES_192_CBC3_SHA

#define SSL3_CK_ADH_RC4_40_MD5			0x03000017
#define SSL3_CK_ADH_RC4_128_MD5			0x03000018
#define SSL3_CK_ADH_DES_40_CBC_SHA		0x03000019
#define SSL3_CK_ADH_DES_64_CBC_SHA		0x0300001A
#define SSL3_CK_ADH_DES_192_CBC_SHA		0x0300001B

#if 0
	#define SSL3_CK_FZA_DMS_NULL_SHA		0x0300001C
	#define SSL3_CK_FZA_DMS_FZA_SHA			0x0300001D
	#if 0 /* Because it clashes with KRB5, is never used any more, and is safe
		 to remove according to David Hopwood <david.hopwood@zetnet.co.uk>
		 of the ietf-tls list */
	#define SSL3_CK_FZA_DMS_RC4_SHA			0x0300001E
	#endif
#endif

/*    VRS Additional Kerberos5 entries
 */
#define SSL3_CK_KRB5_DES_64_CBC_SHA		0x0300001E
#define SSL3_CK_KRB5_DES_192_CBC3_SHA		0x0300001F
#define SSL3_CK_KRB5_RC4_128_SHA		0x03000020
#define SSL3_CK_KRB5_IDEA_128_CBC_SHA	       	0x03000021
#define SSL3_CK_KRB5_DES_64_CBC_MD5       	0x03000022
#define SSL3_CK_KRB5_DES_192_CBC3_MD5       	0x03000023
#define SSL3_CK_KRB5_RC4_128_MD5	       	0x03000024
#define SSL3_CK_KRB5_IDEA_128_CBC_MD5 		0x03000025

#define SSL3_CK_KRB5_DES_40_CBC_SHA 		0x03000026
#define SSL3_CK_KRB5_RC2_40_CBC_SHA 		0x03000027
#define SSL3_CK_KRB5_RC4_40_SHA	 		0x03000028
#define SSL3_CK_KRB5_DES_40_CBC_MD5 		0x03000029
#define SSL3_CK_KRB5_RC2_40_CBC_MD5 		0x0300002A
#define SSL3_CK_KRB5_RC4_40_MD5	 		0x0300002B

#define SSL3_TXT_RSA_NULL_MD5			"NULL-MD5"
#define SSL3_TXT_RSA_NULL_SHA			"NULL-SHA"
#define SSL3_TXT_RSA_RC4_40_MD5 		"EXP-RC4-MD5"
#define SSL3_TXT_RSA_RC4_128_MD5		"RC4-MD5"
#define SSL3_TXT_RSA_RC4_128_SHA		"RC4-SHA"
#define SSL3_TXT_RSA_RC2_40_MD5			"EXP-RC2-CBC-MD5"
#define SSL3_TXT_RSA_IDEA_128_SHA		"IDEA-CBC-SHA"
#define SSL3_TXT_RSA_DES_40_CBC_SHA		"EXP-DES-CBC-SHA"
#define SSL3_TXT_RSA_DES_64_CBC_SHA		"DES-CBC-SHA"
#define SSL3_TXT_RSA_DES_192_CBC3_SHA		"DES-CBC3-SHA"

#define SSL3_TXT_DH_DSS_DES_40_CBC_SHA		"EXP-DH-DSS-DES-CBC-SHA"
#define SSL3_TXT_DH_DSS_DES_64_CBC_SHA		"DH-DSS-DES-CBC-SHA"
#define SSL3_TXT_DH_DSS_DES_192_CBC3_SHA 	"DH-DSS-DES-CBC3-SHA"
#define SSL3_TXT_DH_RSA_DES_40_CBC_SHA		"EXP-DH-RSA-DES-CBC-SHA"
#define SSL3_TXT_DH_RSA_DES_64_CBC_SHA		"DH-RSA-DES-CBC-SHA"
#define SSL3_TXT_DH_RSA_DES_192_CBC3_SHA 	"DH-RSA-DES-CBC3-SHA"

#define SSL3_TXT_DHE_DSS_DES_40_CBC_SHA		"EXP-DHE-DSS-DES-CBC-SHA"
#define SSL3_TXT_DHE_DSS_DES_64_CBC_SHA		"DHE-DSS-DES-CBC-SHA"
#define SSL3_TXT_DHE_DSS_DES_192_CBC3_SHA	"DHE-DSS-DES-CBC3-SHA"
#define SSL3_TXT_DHE_RSA_DES_40_CBC_SHA		"EXP-DHE-RSA-DES-CBC-SHA"
#define SSL3_TXT_DHE_RSA_DES_64_CBC_SHA		"DHE-RSA-DES-CBC-SHA"
#define SSL3_TXT_DHE_RSA_DES_192_CBC3_SHA	"DHE-RSA-DES-CBC3-SHA"

/* This next block of six "EDH" labels is for backward compatibility
   with older versions of OpenSSL.  New code should use the six "DHE"
   labels above instead:
 */
#define SSL3_TXT_EDH_DSS_DES_40_CBC_SHA		"EXP-EDH-DSS-DES-CBC-SHA"
#define SSL3_TXT_EDH_DSS_DES_64_CBC_SHA		"EDH-DSS-DES-CBC-SHA"
#define SSL3_TXT_EDH_DSS_DES_192_CBC3_SHA	"EDH-DSS-DES-CBC3-SHA"
#define SSL3_TXT_EDH_RSA_DES_40_CBC_SHA		"EXP-EDH-RSA-DES-CBC-SHA"
#define SSL3_TXT_EDH_RSA_DES_64_CBC_SHA		"EDH-RSA-DES-CBC-SHA"
#define SSL3_TXT_EDH_RSA_DES_192_CBC3_SHA	"EDH-RSA-DES-CBC3-SHA"

#define SSL3_TXT_ADH_RC4_40_MD5			"EXP-ADH-RC4-MD5"
#define SSL3_TXT_ADH_RC4_128_MD5		"ADH-RC4-MD5"
#define SSL3_TXT_ADH_DES_40_CBC_SHA		"EXP-ADH-DES-CBC-SHA"
#define SSL3_TXT_ADH_DES_64_CBC_SHA		"ADH-DES-CBC-SHA"
#define SSL3_TXT_ADH_DES_192_CBC_SHA		"ADH-DES-CBC3-SHA"

#if 0
	#define SSL3_TXT_FZA_DMS_NULL_SHA		"FZA-NULL-SHA"
	#define SSL3_TXT_FZA_DMS_FZA_SHA		"FZA-FZA-CBC-SHA"
	#define SSL3_TXT_FZA_DMS_RC4_SHA		"FZA-RC4-SHA"
#endif

#define SSL3_TXT_KRB5_DES_64_CBC_SHA		"KRB5-DES-CBC-SHA"
#define SSL3_TXT_KRB5_DES_192_CBC3_SHA		"KRB5-DES-CBC3-SHA"
#define SSL3_TXT_KRB5_RC4_128_SHA		"KRB5-RC4-SHA"
#define SSL3_TXT_KRB5_IDEA_128_CBC_SHA	       	"KRB5-IDEA-CBC-SHA"
#define SSL3_TXT_KRB5_DES_64_CBC_MD5       	"KRB5-DES-CBC-MD5"
#define SSL3_TXT_KRB5_DES_192_CBC3_MD5       	"KRB5-DES-CBC3-MD5"
#define SSL3_TXT_KRB5_RC4_128_MD5		"KRB5-RC4-MD5"
#define SSL3_TXT_KRB5_IDEA_128_CBC_MD5 		"KRB5-IDEA-CBC-MD5"

#define SSL3_TXT_KRB5_DES_40_CBC_SHA 		"EXP-KRB5-DES-CBC-SHA"
#define SSL3_TXT_KRB5_RC2_40_CBC_SHA 		"EXP-KRB5-RC2-CBC-SHA"
#define SSL3_TXT_KRB5_RC4_40_SHA	 	"EXP-KRB5-RC4-SHA"
#define SSL3_TXT_KRB5_DES_40_CBC_MD5 		"EXP-KRB5-DES-CBC-MD5"
#define SSL3_TXT_KRB5_RC2_40_CBC_MD5 		"EXP-KRB5-RC2-CBC-MD5"
#define SSL3_TXT_KRB5_RC4_40_MD5	 	"EXP-KRB5-RC4-MD5"

#define SSL3_SSL_SESSION_ID_LENGTH		32
#define SSL3_MAX_SSL_SESSION_ID_LENGTH		32

#define SSL3_MASTER_SECRET_SIZE			48
#define SSL3_RANDOM_SIZE			32
#define SSL3_SESSION_ID_SIZE			32
#define SSL3_RT_HEADER_LENGTH			5

#define SSL3_HM_HEADER_LENGTH                  4

#ifndef SSL3_ALIGN_PAYLOAD
 /* Some will argue that this increases memory footprint, but it's
  * not actually true. Point is that malloc has to return at least
  * 64-bit aligned pointers, meaning that allocating 5 bytes wastes
  * 3 bytes in either case. Suggested pre-gaping simply moves these
  * wasted bytes from the end of allocated region to its front,
  * but makes data payload aligned, which improves performance:-) */
# define SSL3_ALIGN_PAYLOAD			8
#else
# if (SSL3_ALIGN_PAYLOAD&(SSL3_ALIGN_PAYLOAD-1))!=0
#  error "insane SSL3_ALIGN_PAYLOAD"
#  undef SSL3_ALIGN_PAYLOAD
# endif
#endif

/* This is the maximum MAC (digest) size used by the SSL library.
 * Currently maximum of 20 is used by SHA1, but we reserve for
 * future extension for 512-bit hashes.
 */

#define SSL3_RT_MAX_MD_SIZE			64

/* Maximum block size used in all ciphersuites. Currently 16 for AES.
 */

#define	SSL_RT_MAX_CIPHER_BLOCK_SIZE		16

#define SSL3_RT_MAX_EXTRA			(16384)

/* Maximum plaintext length: defined by SSL/TLS standards */
#define SSL3_RT_MAX_PLAIN_LENGTH		16384
/* Maximum compression overhead: defined by SSL/TLS standards */
#define SSL3_RT_MAX_COMPRESSED_OVERHEAD		1024

/* The standards give a maximum encryption overhead of 1024 bytes.
 * In practice the value is lower than this. The overhead is the maximum
 * number of padding bytes (256) plus the mac size.
 */
#define SSL3_RT_MAX_ENCRYPTED_OVERHEAD	(256 + SSL3_RT_MAX_MD_SIZE)

/* OpenSSL currently only uses a padding length of at most one block so
 * the send overhead is smaller.
 */

#define SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD \
			(SSL_RT_MAX_CIPHER_BLOCK_SIZE + SSL3_RT_MAX_MD_SIZE)

/* If compression isn't used don't include the compression overhead */

#ifdef OPENSSL_NO_COMP
#define SSL3_RT_MAX_COMPRESSED_LENGTH		SSL3_RT_MAX_PLAIN_LENGTH
#else
#define SSL3_RT_MAX_COMPRESSED_LENGTH	\
		(SSL3_RT_MAX_PLAIN_LENGTH+SSL3_RT_MAX_COMPRESSED_OVERHEAD)
#endif
#define SSL3_RT_MAX_ENCRYPTED_LENGTH	\
		(SSL3_RT_MAX_ENCRYPTED_OVERHEAD+SSL3_RT_MAX_COMPRESSED_LENGTH)
#define SSL3_RT_MAX_PACKET_SIZE		\
		(SSL3_RT_MAX_ENCRYPTED_LENGTH+SSL3_RT_HEADER_LENGTH)

#define SSL3_MD_CLIENT_FINISHED_CONST	"\x43\x4C\x4E\x54"
#define SSL3_MD_SERVER_FINISHED_CONST	"\x53\x52\x56\x52"

#define SSL3_VERSION			0x0300
#define SSL3_VERSION_MAJOR		0x03
#define SSL3_VERSION_MINOR		0x00

#define SSL3_RT_CHANGE_CIPHER_SPEC	20
#define SSL3_RT_ALERT			21
#define SSL3_RT_HANDSHAKE		22
#define SSL3_RT_APPLICATION_DATA	23
#define TLS1_RT_HEARTBEAT		24

/* Pseudo content types to indicate additional parameters */
#define TLS1_RT_CRYPTO			0x1000
#define TLS1_RT_CRYPTO_PREMASTER	(TLS1_RT_CRYPTO | 0x1)
#define TLS1_RT_CRYPTO_CLIENT_RANDOM	(TLS1_RT_CRYPTO | 0x2)
#define TLS1_RT_CRYPTO_SERVER_RANDOM	(TLS1_RT_CRYPTO | 0x3)
#define TLS1_RT_CRYPTO_MASTER		(TLS1_RT_CRYPTO | 0x4)

#define TLS1_RT_CRYPTO_READ		0x0000
#define TLS1_RT_CRYPTO_WRITE		0x0100
#define TLS1_RT_CRYPTO_MAC		(TLS1_RT_CRYPTO | 0x5)
#define TLS1_RT_CRYPTO_KEY		(TLS1_RT_CRYPTO | 0x6)
#define TLS1_RT_CRYPTO_IV		(TLS1_RT_CRYPTO | 0x7)
#define TLS1_RT_CRYPTO_FIXED_IV		(TLS1_RT_CRYPTO | 0x8)

/* Pseudo content type for SSL/TLS header info */
#define SSL3_RT_HEADER			0x100

#define SSL3_AL_WARNING			1
#define SSL3_AL_FATAL			2

#define SSL3_AD_CLOSE_NOTIFY		 0
#define SSL3_AD_UNEXPECTED_MESSAGE	10	/* fatal */
#define SSL3_AD_BAD_RECORD_MAC		20	/* fatal */
#define SSL3_AD_DECOMPRESSION_FAILURE	30	/* fatal */
#define SSL3_AD_HANDSHAKE_FAILURE	40	/* fatal */
#define SSL3_AD_NO_CERTIFICATE		41
#define SSL3_AD_BAD_CERTIFICATE		42
#define SSL3_AD_UNSUPPORTED_CERTIFICATE	43
#define SSL3_AD_CERTIFICATE_REVOKED	44
#define SSL3_AD_CERTIFICATE_EXPIRED	45
#define SSL3_AD_CERTIFICATE_UNKNOWN	46
#define SSL3_AD_ILLEGAL_PARAMETER	47	/* fatal */

#define TLS1_HB_REQUEST		1
#define TLS1_HB_RESPONSE	2
	
#ifndef OPENSSL_NO_SSL_INTERN

typedef struct ssl3_record_st
	{
		/* type of record */
/*r */	int type;
		/* How many bytes available */
/*rw*/	unsigned int length;
		/* read/write offset into 'buf' */
/*r */	unsigned int off;
		/* pointer to the record data */
/*rw*/	unsigned char *data;
		/* where the decode bytes are */
/*rw*/	unsigned char *input;
		/* only used with decompression - malloc()ed */
/*r */	unsigned char *comp;
		/* epoch number, needed by DTLS1 */
/*r */  unsigned long epoch;
		/* sequence number, needed by DTLS1 */
/*r */  unsigned char seq_num[8]; 
	} SSL3_RECORD;

typedef struct ssl3_buffer_st
	{
	/* at least SSL3_RT_MAX_PACKET_SIZE bytes, see ssl3_setup_buffers() */
	unsigned char *buf;
	/* buffer size */
	size_t len;
	/* where to 'copy from' */<