/* crypto/evp/bio_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.]

 */

/*

 © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 */

#include <stdio.h>

#include <errno.h>

#include "cryptlib.h"

#include <openssl/buffer.h>

#include <openssl/evp.h>

#if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))

#include "libcrypto_wsd_macros.h"

#include "libcrypto_wsd.h"

#endif

static int enc_write(BIO *h, const char *buf, int num);

static int enc_read(BIO *h, char *buf, int size);

/*static int enc_puts(BIO *h, const char *str); */

/*static int enc_gets(BIO *h, char *str, int size); */

static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);

static int enc_new(BIO *h);

static int enc_free(BIO *data);

static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);

#define ENC_BLOCK_SIZE	(1024*4)

#define BUF_OFFSET	(EVP_MAX_BLOCK_LENGTH*2)

typedef struct enc_struct

	{

	int buf_len;

	int buf_off;

	int cont;		/* <= 0 when finished */

	int finished;

	int ok;			/* bad decrypt */

	EVP_CIPHER_CTX cipher;

	/* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate

	 * can return up to a block more data than is presented to it

	 */

	char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2];

	} BIO_ENC_CTX;

#ifndef EMULATOR

static BIO_METHOD methods_enc=

	{

	BIO_TYPE_CIPHER,"cipher",

	enc_write,

	enc_read,

	NULL, /* enc_puts, */

	NULL, /* enc_gets, */

	enc_ctrl,

	enc_new,

	enc_free,

	enc_callback_ctrl,

	};

#else

GET_STATIC_VAR_FROM_TLS(methods_enc,bio_enc,BIO_METHOD)

#define methods_enc (*GET_WSD_VAR_NAME(methods_enc,bio_enc, s)())

const BIO_METHOD temp_s_methods_enc=

	{

	BIO_TYPE_CIPHER,"cipher",

	enc_write,

	enc_read,

	NULL, /* enc_puts, */

	NULL, /* enc_gets, */

	enc_ctrl,

	enc_new,

	enc_free,

	enc_callback_ctrl,

	};

#endif	

EXPORT_C BIO_METHOD *BIO_f_cipher(void)

	{

	return(&methods_enc);

	}

static int enc_new(BIO *bi)

	{

	BIO_ENC_CTX *ctx;

	ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX));

	if (ctx == NULL) return(0);

	EVP_CIPHER_CTX_init(&ctx->cipher);

	ctx->buf_len=0;

	ctx->buf_off=0;

	ctx->cont=1;

	ctx->finished=0;

	ctx->ok=1;

	bi->init=0;

	bi->ptr=(char *)ctx;

	bi->flags=0;

	return(1);

	}

static int enc_free(BIO *a)

	{

	BIO_ENC_CTX *b;

	if (a == NULL) return(0);

	b=(BIO_ENC_CTX *)a->ptr;

	EVP_CIPHER_CTX_cleanup(&(b->cipher));

	OPENSSL_cleanse(a->ptr,sizeof(BIO_ENC_CTX));

	OPENSSL_free(a->ptr);

	a->ptr=NULL;

	a->init=0;

	a->flags=0;

	return(1);

	}

static int enc_read(BIO *b, char *out, int outl)

	{

	int ret=0,i;

	BIO_ENC_CTX *ctx;

	if (out == NULL) return(0);

	ctx=(BIO_ENC_CTX *)b->ptr;

	if ((ctx == NULL) || (b->next_bio == NULL)) return(0);

	/* First check if there are bytes decoded/encoded */

	if (ctx->buf_len > 0)

		{

		i=ctx->buf_len-ctx->buf_off;

		if (i > outl) i=outl;

		memcpy(out,&(ctx->buf[ctx->buf_off]),i);

		ret=i;

		out+=i;

		outl-=i;

		ctx->buf_off+=i;

		if (ctx->buf_len == ctx->buf_off)

			{

			ctx->buf_len=0;

			ctx->buf_off=0;

			}

		}

	/* At this point, we have room of outl bytes and an empty

	 * buffer, so we should read in some more. */

	while (outl > 0)

		{

		if (ctx->cont <= 0) break;

		/* read in at IV offset, read the EVP_Cipher

		 * documentation about why */

		i=BIO_read(b->next_bio,&(ctx->buf[BUF_OFFSET]),ENC_BLOCK_SIZE);

		if (i <= 0)

			{

			/* Should be continue next time we are called? */

			if (!BIO_should_retry(b->next_bio))

				{

				ctx->cont=i;

				i=EVP_CipherFinal_ex(&(ctx->cipher),

					(unsigned char *)ctx->buf,

					&(ctx->buf_len));

				ctx->ok=i;

				ctx->buf_off=0;

				}

			else 

				{

				ret=(ret == 0)?i:ret;

				break;

				}

			}

		else

			{

			EVP_CipherUpdate(&(ctx->cipher),

				(unsigned char *)ctx->buf,&ctx->buf_len,

				(unsigned char *)&(ctx->buf[BUF_OFFSET]),i);

			ctx->cont=1;

			/* Note: it is possible for EVP_CipherUpdate to

			 * decrypt zero bytes because this is or looks like

			 * the final block: if this happens we should retry

			 * and either read more data or decrypt the final

			 * block

			 */

			if(ctx->buf_len == 0) continue;

			}

		if (ctx->buf_len <= outl)

			i=ctx->buf_len;

		else

			i=outl;

		if (i <= 0) break;

		memcpy(out,ctx->buf,i);

		ret+=i;

		ctx->buf_off=i;

		outl-=i;

		out+=i;

		}

	BIO_clear_retry_flags(b);

	BIO_copy_next_retry(b);

	return((ret == 0)?ctx->cont:ret);

	}

static int enc_write(BIO *b, const char *in, int inl)

	{

	int ret=0,n,i;

	BIO_ENC_CTX *ctx;

	ctx=(BIO_ENC_CTX *)b->ptr;

	ret=inl;

	BIO_clear_retry_flags(b);

	n=ctx->buf_len-ctx->buf_off;

	while (n > 0)

		{

		i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);

		if (i <= 0)

			{

			BIO_copy_next_retry(b);

			return(i);

			}

		ctx->buf_off+=i;

		n-=i;

		}

	/* at this point all pending data has been written */

	if ((in == NULL) || (inl <= 0)) return(0);

	ctx->buf_off=0;

	while (inl > 0)

		{

		n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl;

		EVP_CipherUpdate(&(ctx->cipher),

			(unsigned char *)ctx->buf,&ctx->buf_len,

			(unsigned char *)in,n);

		inl-=n;

		in+=n;

		ctx->buf_off=0;

		n=ctx->buf_len;

		while (n > 0)

			{

			i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);

			if (i <= 0)

				{

				BIO_copy_next_retry(b);

				return (ret == inl) ? i : ret - inl;

				}

			n-=i;

			ctx->buf_off+=i;

			}

		ctx->buf_len=0;

		ctx->buf_off=0;

		}

	BIO_copy_next_retry(b);

	return(ret);

	}

static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)

	{

	BIO *dbio;

	BIO_ENC_CTX *ctx,*dctx;

	long ret=1;

	int i;

	EVP_CIPHER_CTX **c_ctx;

	ctx=(BIO_ENC_CTX *)b->ptr;

	switch (cmd)

		{

	case BIO_CTRL_RESET:

		ctx->ok=1;

		ctx->finished=0;

		EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL,

			ctx->cipher.encrypt);

		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

	case BIO_CTRL_EOF:	/* More to read */

		if (ctx->cont <= 0)

			ret=1;

		else

			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

	case BIO_CTRL_WPENDING:

		ret=ctx->buf_len-ctx->buf_off;

		if (ret <= 0)

			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

	case BIO_CTRL_PENDING: /* More to read in buffer */

		ret=ctx->buf_len-ctx->buf_off;

		if (ret <= 0)

			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

	case BIO_CTRL_FLUSH:

		/* do a final write */

again:

		while (ctx->buf_len != ctx->buf_off)

			{

			i=enc_write(b,NULL,0);

			if (i < 0)

				return i;

			}

		if (!ctx->finished)

			{

			ctx->finished=1;

			ctx->buf_off=0;

			ret=EVP_CipherFinal_ex(&(ctx->cipher),

				(unsigned char *)ctx->buf,

				&(ctx->buf_len));

			ctx->ok=(int)ret;

			if (ret <= 0) break;

			/* push out the bytes */

			goto again;

			}

		/* Finally flush the underlying BIO */

		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

	case BIO_C_GET_CIPHER_STATUS:

		ret=(long)ctx->ok;

		break;

	case BIO_C_DO_STATE_MACHINE:

		BIO_clear_retry_flags(b);

		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		BIO_copy_next_retry(b);

		break;

	case BIO_C_GET_CIPHER_CTX:

		c_ctx=(EVP_CIPHER_CTX **)ptr;

		(*c_ctx)= &(ctx->cipher);

		b->init=1;

		break;

	case BIO_CTRL_DUP:

		dbio=(BIO *)ptr;

		dctx=(BIO_ENC_CTX *)dbio->ptr;

		memcpy(&(dctx->cipher),&(ctx->cipher),sizeof(ctx->cipher));

		dbio->init=1;

		break;

	default:

		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);

		break;

		}

	return(ret);

	}

static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)

	{

	long ret=1;

	if (b->next_bio == NULL) return(0);

	switch (cmd)

		{

	default:

		ret=BIO_callback_ctrl(b->next_bio,cmd,fp);

		break;

		}

	return(ret);

	}

/*

void BIO_set_cipher_ctx(b,c)

BIO *b;

EVP_CIPHER_ctx *c;

	{

	if (b == NULL) return;

	if ((b->callback != NULL) &&

		(b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))

		return;

	b->init=1;

	ctx=(BIO_ENC_CTX *)b->ptr;

	memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));

	if (b->callback != NULL)

		b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);

	}

*/

EXPORT_C void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,

	     const unsigned char *i, int e)

	{

	BIO_ENC_CTX *ctx;

	if (b == NULL) return;

	if ((b->callback != NULL) &&

		(b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0))

		return;

	b->init=1;

	ctx=(BIO_ENC_CTX *)b->ptr;

	EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e);

	if (b->callback != NULL)

		b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L);

	}