crypto/evp/evp_enc.c - third_party/openssl - Git at Google

 /* crypto/evp/evp_enc.c */
 /* 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 "cryptlib.h"
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include "evp_locl.h"

 const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;

 void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
 	{
 	memset(ctx,0,sizeof(EVP_CIPHER_CTX));
 	/* ctx->cipher=NULL; */
 	}

 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 	     unsigned char *key, unsigned char *iv, int enc)
 	{
 	if(enc && (enc != -1)) enc = 1;
 	if (cipher) {
 		ctx->cipher=cipher;
 		ctx->key_len = cipher->key_len;
 		ctx->flags = 0;
 		if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
 			if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
 				EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
 				return 0;
 			}
 		}
 	} else if(!ctx->cipher) {
 		EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
 		return 0;
 	}
 	if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
 		switch(EVP_CIPHER_CTX_mode(ctx)) {

 			case EVP_CIPH_STREAM_CIPHER:
 			case EVP_CIPH_ECB_MODE:
 			break;

 			case EVP_CIPH_CFB_MODE:
 			case EVP_CIPH_OFB_MODE:

 			ctx->num = 0;

 			case EVP_CIPH_CBC_MODE:

 			if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 			memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 			break;

 			default:
 			return 0;
 			break;
 		}
 	}

 	if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
 		if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
 	}
 	if(enc != -1) ctx->encrypt=enc;
 	ctx->buf_len=0;
 	return 1;
 	}

 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 	     unsigned char *in, int inl)
 	{
 	if (ctx->encrypt)
 		return EVP_EncryptUpdate(ctx,out,outl,in,inl);
 	else	return EVP_DecryptUpdate(ctx,out,outl,in,inl);
 	}

 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 	{
 	if (ctx->encrypt)
 		return EVP_EncryptFinal(ctx,out,outl);
 	else	return(EVP_DecryptFinal(ctx,out,outl));
 	}

 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 	     unsigned char *key, unsigned char *iv)
 	{
 	return EVP_CipherInit(ctx, cipher, key, iv, 1);
 	}

 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
 	     unsigned char *key, unsigned char *iv)
 	{
 	return EVP_CipherInit(ctx, cipher, key, iv, 0);
 	}


 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 	     unsigned char *in, int inl)
 	{
 	int i,j,bl;

 	i=ctx->buf_len;
 	bl=ctx->cipher->block_size;
 	*outl=0;
 	if ((inl == 0) && (i != bl)) return 1;
 	if (i != 0)
 		{
 		if (i+inl < bl)
 			{
 			memcpy(&(ctx->buf[i]),in,inl);
 			ctx->buf_len+=inl;
 			return 1;
 			}
 		else
 			{
 			j=bl-i;
 			if (j != 0) memcpy(&(ctx->buf[i]),in,j);
 			if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
 			inl-=j;
 			in+=j;
 			out+=bl;
 			*outl+=bl;
 			}
 		}
 	i=inl%bl; /* how much is left */
 	inl-=i;
 	if (inl > 0)
 		{
 		if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
 		*outl+=inl;
 		}

 	if (i != 0)
 		memcpy(ctx->buf,&(in[inl]),i);
 	ctx->buf_len=i;
 	return 1;
 	}

 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 	{
 	int i,n,b,bl;

 	b=ctx->cipher->block_size;
 	if (b == 1)
 		{
 		*outl=0;
 		return 1;
 		}
 	bl=ctx->buf_len;
 	if (ctx->flags & EVP_CIPH_NO_PADDING)
 		{
 		if(bl)
 			{
 			EVPerr(EVP_F_EVP_ENCRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 			return 0;
 			}
 		*outl = 0;
 		return 1;
 		}
 	n=b-bl;
 	for (i=bl; i<b; i++)
 		ctx->buf[i]=n;
 	if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
 	*outl=b;
 	return 1;
 	}

 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
 	     unsigned char *in, int inl)
 	{
 	int b,bl,n;
 	int keep_last=0;

 	*outl=0;
 	if (inl == 0) return 1;

 	if (ctx->flags & EVP_CIPH_NO_PADDING)
 		return EVP_EncryptUpdate(ctx, out, outl, in, inl);

 	b=ctx->cipher->block_size;
 	if (b > 1)
 		{
 		/* Is the input a multiple of the block size? */
 		bl=ctx->buf_len;
 		n=inl+bl;
 		if (n%b == 0)
 			{
 			if (inl < b) /* must be 'just one' buff */
 				{
 				memcpy(&(ctx->buf[bl]),in,inl);
 				ctx->buf_len=b;
 				*outl=0;
 				return 1;
 				}
 			keep_last=1;
 			inl-=b; /* don't do the last block */
 			}
 		}
 	if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;

 	/* if we have 'decrypted' a multiple of block size, make sure
 	 * we have a copy of this last block */
 	if (keep_last)
 		{
 		memcpy(&(ctx->buf[0]),&(in[inl]),b);
 #ifdef DEBUG
 		if (ctx->buf_len != 0)
 			{
 			abort();
 			}
 #endif
 		ctx->buf_len=b;
 		}
 	return 1;
 	}

 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
 	{
 	int i,b;
 	int n;

 	*outl=0;
 	b=ctx->cipher->block_size;
 	if (ctx->flags & EVP_CIPH_NO_PADDING)
 		{
 		if(ctx->buf_len)
 			{
 			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
 			return 0;
 			}
 		*outl = 0;
 		return 1;
 		}
 	if (b > 1)
 		{
 		if (ctx->buf_len != b)
 			{
 			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
 			return(0);
 			}
 		if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
 		if (n != b)
 			return(0);
 		n=ctx->buf[b-1];
 		if (n > b)
 			{
 			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 			return(0);
 			}
 		for (i=0; i<n; i++)
 			{
 			if (ctx->buf[--b] != n)
 				{
 				EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
 				return(0);
 				}
 			}
 		n=ctx->cipher->block_size-n;
 		for (i=0; i<n; i++)
 			out[i]=ctx->buf[i];
 		*outl=n;
 		}
 	else
 		*outl=0;
 	return(1);
 	}

 int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
 	{
 	if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
 		{
 		if(!c->cipher->cleanup(c)) return 0;
 		}
 	memset(c,0,sizeof(EVP_CIPHER_CTX));
 	return 1;
 	}

 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
 	{
 	if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
 		return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
 	if(c->key_len == keylen) return 1;
 	if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
 		{
 		c->key_len = keylen;
 		return 1;
 		}
 	EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
 	return 0;
 	}

 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
 	{
 	if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
 	else ctx->flags |= EVP_CIPH_NO_PADDING;
 	return 1;
 	}

 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
 {
 	int ret;
 	if(!ctx->cipher) {
 		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
 		return 0;
 	}

 	if(!ctx->cipher->ctrl) {
 		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
 		return 0;
 	}

 	ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
 	if(ret == -1) {
 		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
 		return 0;
 	}
 	return ret;
 }
	/* crypto/evp/evp_enc.c */
	/* 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 "cryptlib.h"
	#include <openssl/evp.h>
	#include <openssl/err.h>
	#include "evp_locl.h"

	const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;

	void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
	{
	memset(ctx,0,sizeof(EVP_CIPHER_CTX));
	/* ctx->cipher=NULL; */
	}

	int EVP_CipherInit(EVP_CIPHER_CTX ctx, const EVP_CIPHER cipher,
	unsigned char key, unsigned char iv, int enc)
	{
	if(enc && (enc != -1)) enc = 1;
	if (cipher) {
	ctx->cipher=cipher;
	ctx->key_len = cipher->key_len;
	ctx->flags = 0;
	if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
	if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
	EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
	return 0;
	}
	}
	} else if(!ctx->cipher) {
	EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
	return 0;
	}
	if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
	switch(EVP_CIPHER_CTX_mode(ctx)) {

	case EVP_CIPH_STREAM_CIPHER:
	case EVP_CIPH_ECB_MODE:
	break;

	case EVP_CIPH_CFB_MODE:
	case EVP_CIPH_OFB_MODE:

	ctx->num = 0;

	case EVP_CIPH_CBC_MODE:

	if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
	memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
	break;

	default:
	return 0;
	break;
	}
	}

	if(key \|\| (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
	if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
	}
	if(enc != -1) ctx->encrypt=enc;
	ctx->buf_len=0;
	return 1;
	}

	int EVP_CipherUpdate(EVP_CIPHER_CTX ctx, unsigned char out, int *outl,
	unsigned char *in, int inl)
	{
	if (ctx->encrypt)
	return EVP_EncryptUpdate(ctx,out,outl,in,inl);
	else return EVP_DecryptUpdate(ctx,out,outl,in,inl);
	}

	int EVP_CipherFinal(EVP_CIPHER_CTX ctx, unsigned char out, int *outl)
	{
	if (ctx->encrypt)
	return EVP_EncryptFinal(ctx,out,outl);
	else return(EVP_DecryptFinal(ctx,out,outl));
	}

	int EVP_EncryptInit(EVP_CIPHER_CTX ctx, const EVP_CIPHER cipher,
	unsigned char key, unsigned char iv)
	{
	return EVP_CipherInit(ctx, cipher, key, iv, 1);
	}

	int EVP_DecryptInit(EVP_CIPHER_CTX ctx, const EVP_CIPHER cipher,
	unsigned char key, unsigned char iv)
	{
	return EVP_CipherInit(ctx, cipher, key, iv, 0);
	}


	int EVP_EncryptUpdate(EVP_CIPHER_CTX ctx, unsigned char out, int *outl,
	unsigned char *in, int inl)
	{
	int i,j,bl;

	i=ctx->buf_len;
	bl=ctx->cipher->block_size;
	*outl=0;
	if ((inl == 0) && (i != bl)) return 1;
	if (i != 0)
	{
	if (i+inl < bl)
	{
	memcpy(&(ctx->buf[i]),in,inl);
	ctx->buf_len+=inl;
	return 1;
	}
	else
	{
	j=bl-i;
	if (j != 0) memcpy(&(ctx->buf[i]),in,j);
	if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
	inl-=j;
	in+=j;
	out+=bl;
	*outl+=bl;
	}
	}
	i=inl%bl; /* how much is left */
	inl-=i;
	if (inl > 0)
	{
	if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
	*outl+=inl;
	}

	if (i != 0)
	memcpy(ctx->buf,&(in[inl]),i);
	ctx->buf_len=i;
	return 1;
	}

	int EVP_EncryptFinal(EVP_CIPHER_CTX ctx, unsigned char out, int *outl)
	{
	int i,n,b,bl;

	b=ctx->cipher->block_size;
	if (b == 1)
	{
	*outl=0;
	return 1;
	}
	bl=ctx->buf_len;
	if (ctx->flags & EVP_CIPH_NO_PADDING)
	{
	if(bl)
	{
	EVPerr(EVP_F_EVP_ENCRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
	return 0;
	}
	*outl = 0;
	return 1;
	}
	n=b-bl;
	for (i=bl; i<b; i++)
	ctx->buf[i]=n;
	if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
	*outl=b;
	return 1;
	}

	int EVP_DecryptUpdate(EVP_CIPHER_CTX ctx, unsigned char out, int *outl,
	unsigned char *in, int inl)
	{
	int b,bl,n;
	int keep_last=0;

	*outl=0;
	if (inl == 0) return 1;

	if (ctx->flags & EVP_CIPH_NO_PADDING)
	return EVP_EncryptUpdate(ctx, out, outl, in, inl);

	b=ctx->cipher->block_size;
	if (b > 1)
	{
	/* Is the input a multiple of the block size? */
	bl=ctx->buf_len;
	n=inl+bl;
	if (n%b == 0)
	{
	if (inl < b) /* must be 'just one' buff */
	{
	memcpy(&(ctx->buf[bl]),in,inl);
	ctx->buf_len=b;
	*outl=0;
	return 1;
	}
	keep_last=1;
	inl-=b; /* don't do the last block */
	}
	}
	if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;

	/* if we have 'decrypted' a multiple of block size, make sure
	* we have a copy of this last block */
	if (keep_last)
	{
	memcpy(&(ctx->buf[0]),&(in[inl]),b);
	#ifdef DEBUG
	if (ctx->buf_len != 0)
	{
	abort();
	}
	#endif
	ctx->buf_len=b;
	}
	return 1;
	}

	int EVP_DecryptFinal(EVP_CIPHER_CTX ctx, unsigned char out, int *outl)
	{
	int i,b;
	int n;

	*outl=0;
	b=ctx->cipher->block_size;
	if (ctx->flags & EVP_CIPH_NO_PADDING)
	{
	if(ctx->buf_len)
	{
	EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
	return 0;
	}
	*outl = 0;
	return 1;
	}
	if (b > 1)
	{
	if (ctx->buf_len != b)
	{
	EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
	return(0);
	}
	if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
	if (n != b)
	return(0);
	n=ctx->buf[b-1];
	if (n > b)
	{
	EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
	return(0);
	}
	for (i=0; i<n; i++)
	{
	if (ctx->buf[--b] != n)
	{
	EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
	return(0);
	}
	}
	n=ctx->cipher->block_size-n;
	for (i=0; i<n; i++)
	out[i]=ctx->buf[i];
	*outl=n;
	}
	else
	*outl=0;
	return(1);
	}

	int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
	{
	if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
	{
	if(!c->cipher->cleanup(c)) return 0;
	}
	memset(c,0,sizeof(EVP_CIPHER_CTX));
	return 1;
	}

	int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
	{
	if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
	return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
	if(c->key_len == keylen) return 1;
	if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
	{
	c->key_len = keylen;
	return 1;
	}
	EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
	return 0;
	}

	int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
	{
	if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
	else ctx->flags \|= EVP_CIPH_NO_PADDING;
	return 1;
	}

	int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX ctx, int type, int arg, void ptr)
	{
	int ret;
	if(!ctx->cipher) {
	EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
	return 0;
	}

	if(!ctx->cipher->ctrl) {
	EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
	return 0;
	}

	ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
	if(ret == -1) {
	EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
	return 0;
	}
	return ret;
	}