text: /* ssl/d1_enc.c */
  /* 
   * DTLS implementation written by Nagendra Modadugu
   * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
   */
  /* ====================================================================
   * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer. 
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    openssl-core@openssl.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   *
   * This product includes cryptographic software written by Eric Young
   * (eay@cryptsoft.com).  This product includes software written by Tim
   * Hudson (tjh@cryptsoft.com).
   *
   */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   * 
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   * 
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from 
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   * 
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * 
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <stdio.h>
  #include "ssl_locl.h"
  #ifndef OPENSSL_NO_COMP
  #include <openssl/comp.h>
  #endif
  #include <openssl/evp.h>
  #include <openssl/hmac.h>
  #include <openssl/md5.h>
  #include <openssl/rand.h>
  #ifdef KSSL_DEBUG
  #include <openssl/des.h>
  #endif
  
  /* dtls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
   *
   * Returns:
   *   0: (in non-constant time) if the record is publically invalid (i.e. too
   *       short etc).
   *   1: if the record's padding is valid / the encryption was successful.
   *   -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
   *       an internal error occured. */
  int dtls1_enc(SSL *s, int send)
  	{
  	SSL3_RECORD *rec;
  	EVP_CIPHER_CTX *ds;
  	unsigned long l;
  	int bs,i,j,k,mac_size=0;
  	const EVP_CIPHER *enc;
  
  	if (send)
  		{
  		if (EVP_MD_CTX_md(s->write_hash))
  			{
  			mac_size=EVP_MD_CTX_size(s->write_hash);
  			if (mac_size < 0)
  				return -1;
  			}
  		ds=s->enc_write_ctx;
  		rec= &(s->s3->wrec);
  		if (s->enc_write_ctx == NULL)
  			enc=NULL;
  		else
  			{
  			enc=EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
  			if ( rec->data != rec->input)
  				/* we can't write into the input stream */
  				fprintf(stderr, "%s:%d: rec->data != rec->input\n",
  					__FILE__, __LINE__);
  			else if ( EVP_CIPHER_block_size(ds->cipher) > 1)
  				{
  				if (RAND_bytes(rec->input, EVP_CIPHER_block_size(ds->cipher)) <= 0)
  					return -1;
  				}
  			}
  		}
  	else
  		{
  		if (EVP_MD_CTX_md(s->read_hash))
  			{
  			mac_size=EVP_MD_CTX_size(s->read_hash);
  			OPENSSL_assert(mac_size >= 0);
  			}
  		ds=s->enc_read_ctx;
  		rec= &(s->s3->rrec);
  		if (s->enc_read_ctx == NULL)
  			enc=NULL;
  		else
  			enc=EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
  		}
  
  #ifdef KSSL_DEBUG
  	printf("dtls1_enc(%d)\n", send);
  #endif    /* KSSL_DEBUG */
  
  	if ((s->session == NULL) || (ds == NULL) ||
  		(enc == NULL))
  		{
  		memmove(rec->data,rec->input,rec->length);
  		rec->input=rec->data;
  		}
  	else
  		{
  		l=rec->length;
  		bs=EVP_CIPHER_block_size(ds->cipher);
  
  		if ((bs != 1) && send)
  			{
  			i=bs-((int)l%bs);
  
  			/* Add weird padding of upto 256 bytes */
  
  			/* we need to add 'i' padding bytes of value j */
  			j=i-1;
  			if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG)
  				{
  				if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
  					j++;
  				}
  			for (k=(int)l; k<(int)(l+i); k++)
  				rec->input[k]=j;
  			l+=i;
  			rec->length+=i;
  			}
  
  #ifdef KSSL_DEBUG
  		{
                  unsigned long ui;
  		printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
                          ds,rec->data,rec->input,l);
  		printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
                          ds->buf_len, ds->cipher->key_len,
                          DES_KEY_SZ, DES_SCHEDULE_SZ,
                          ds->cipher->iv_len);
  		printf("\t\tIV: ");
  		for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
  		printf("\n");
  		printf("\trec->input=");
  		for (ui=0; ui<l; ui++) printf(" %02x", rec->input[ui]);
  		printf("\n");
  		}
  #endif	/* KSSL_DEBUG */
  
  		if (!send)
  			{
  			if (l == 0 || l%bs != 0)
  				return 0;
  			}
  		
  		EVP_Cipher(ds,rec->data,rec->input,l);
  
  #ifdef KSSL_DEBUG
  		{
                  unsigned long i;
                  printf("\trec->data=");
  		for (i=0; i<l; i++)
                          printf(" %02x", rec->data[i]);  printf("\n");
                  }
  #endif	/* KSSL_DEBUG */
  
  		if ((bs != 1) && !send)
  			return tls1_cbc_remove_padding(s, rec, bs, mac_size);
  		}
  	return(1);
  	}
  
  