sl@0: /* crypto/evp/bio_ok.c */
sl@0: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
sl@0:  * All rights reserved.
sl@0:  *
sl@0:  * This package is an SSL implementation written
sl@0:  * by Eric Young (eay@cryptsoft.com).
sl@0:  * The implementation was written so as to conform with Netscapes SSL.
sl@0:  * 
sl@0:  * This library is free for commercial and non-commercial use as long as
sl@0:  * the following conditions are aheared to.  The following conditions
sl@0:  * apply to all code found in this distribution, be it the RC4, RSA,
sl@0:  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
sl@0:  * included with this distribution is covered by the same copyright terms
sl@0:  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
sl@0:  * 
sl@0:  * Copyright remains Eric Young's, and as such any Copyright notices in
sl@0:  * the code are not to be removed.
sl@0:  * If this package is used in a product, Eric Young should be given attribution
sl@0:  * as the author of the parts of the library used.
sl@0:  * This can be in the form of a textual message at program startup or
sl@0:  * in documentation (online or textual) provided with the package.
sl@0:  * 
sl@0:  * Redistribution and use in source and binary forms, with or without
sl@0:  * modification, are permitted provided that the following conditions
sl@0:  * are met:
sl@0:  * 1. Redistributions of source code must retain the copyright
sl@0:  *    notice, this list of conditions and the following disclaimer.
sl@0:  * 2. Redistributions in binary form must reproduce the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer in the
sl@0:  *    documentation and/or other materials provided with the distribution.
sl@0:  * 3. All advertising materials mentioning features or use of this software
sl@0:  *    must display the following acknowledgement:
sl@0:  *    "This product includes cryptographic software written by
sl@0:  *     Eric Young (eay@cryptsoft.com)"
sl@0:  *    The word 'cryptographic' can be left out if the rouines from the library
sl@0:  *    being used are not cryptographic related :-).
sl@0:  * 4. If you include any Windows specific code (or a derivative thereof) from 
sl@0:  *    the apps directory (application code) you must include an acknowledgement:
sl@0:  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
sl@0:  * 
sl@0:  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
sl@0:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
sl@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
sl@0:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
sl@0:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
sl@0:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
sl@0:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
sl@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
sl@0:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
sl@0:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
sl@0:  * SUCH DAMAGE.
sl@0:  * 
sl@0:  * The licence and distribution terms for any publically available version or
sl@0:  * derivative of this code cannot be changed.  i.e. this code cannot simply be
sl@0:  * copied and put under another distribution licence
sl@0:  * [including the GNU Public Licence.]
sl@0:  */
sl@0: 
sl@0: /*
sl@0:  © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.
sl@0:  */
sl@0: /*
sl@0: 	From: Arne Ansper <arne@cyber.ee>
sl@0: 
sl@0: 	Why BIO_f_reliable?
sl@0: 
sl@0: 	I wrote function which took BIO* as argument, read data from it
sl@0: 	and processed it. Then I wanted to store the input file in 
sl@0: 	encrypted form. OK I pushed BIO_f_cipher to the BIO stack
sl@0: 	and everything was OK. BUT if user types wrong password 
sl@0: 	BIO_f_cipher outputs only garbage and my function crashes. Yes
sl@0: 	I can and I should fix my function, but BIO_f_cipher is 
sl@0: 	easy way to add encryption support to many existing applications
sl@0: 	and it's hard to debug and fix them all. 
sl@0: 
sl@0: 	So I wanted another BIO which would catch the incorrect passwords and
sl@0: 	file damages which cause garbage on BIO_f_cipher's output. 
sl@0: 
sl@0: 	The easy way is to push the BIO_f_md and save the checksum at 
sl@0: 	the end of the file. However there are several problems with this
sl@0: 	approach:
sl@0: 
sl@0: 	1) you must somehow separate checksum from actual data. 
sl@0: 	2) you need lot's of memory when reading the file, because you 
sl@0: 	must read to the end of the file and verify the checksum before
sl@0: 	letting the application to read the data. 
sl@0: 	
sl@0: 	BIO_f_reliable tries to solve both problems, so that you can 
sl@0: 	read and write arbitrary long streams using only fixed amount
sl@0: 	of memory.
sl@0: 
sl@0: 	BIO_f_reliable splits data stream into blocks. Each block is prefixed
sl@0: 	with it's length and suffixed with it's digest. So you need only 
sl@0: 	several Kbytes of memory to buffer single block before verifying 
sl@0: 	it's digest. 
sl@0: 
sl@0: 	BIO_f_reliable goes further and adds several important capabilities:
sl@0: 
sl@0: 	1) the digest of the block is computed over the whole stream 
sl@0: 	-- so nobody can rearrange the blocks or remove or replace them.
sl@0: 
sl@0: 	2) to detect invalid passwords right at the start BIO_f_reliable 
sl@0: 	adds special prefix to the stream. In order to avoid known plain-text
sl@0: 	attacks this prefix is generated as follows:
sl@0: 
sl@0: 		*) digest is initialized with random seed instead of 
sl@0: 		standardized one.
sl@0: 		*) same seed is written to output
sl@0: 		*) well-known text is then hashed and the output 
sl@0: 		of the digest is also written to output.
sl@0: 
sl@0: 	reader can now read the seed from stream, hash the same string
sl@0: 	and then compare the digest output.
sl@0: 
sl@0: 	Bad things: BIO_f_reliable knows what's going on in EVP_Digest. I 
sl@0: 	initially wrote and tested this code on x86 machine and wrote the
sl@0: 	digests out in machine-dependent order :( There are people using
sl@0: 	this code and I cannot change this easily without making existing
sl@0: 	data files unreadable.
sl@0: 
sl@0: */
sl@0: 
sl@0: #include <stdio.h>
sl@0: #include <errno.h>
sl@0: #include <assert.h>
sl@0: #include "cryptlib.h"
sl@0: #include <openssl/buffer.h>
sl@0: #include <openssl/bio.h>
sl@0: #include <openssl/evp.h>
sl@0: #include <openssl/rand.h>
sl@0: #if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))
sl@0: #include "libcrypto_wsd_macros.h"
sl@0: #include "libcrypto_wsd.h"
sl@0: #endif
sl@0: 
sl@0: 
sl@0: static int ok_write(BIO *h, const char *buf, int num);
sl@0: static int ok_read(BIO *h, char *buf, int size);
sl@0: static long ok_ctrl(BIO *h, int cmd, long arg1, void *arg2);
sl@0: static int ok_new(BIO *h);
sl@0: static int ok_free(BIO *data);
sl@0: static long ok_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
sl@0: 
sl@0: static void sig_out(BIO* b);
sl@0: static void sig_in(BIO* b);
sl@0: static void block_out(BIO* b);
sl@0: static void block_in(BIO* b);
sl@0: #define OK_BLOCK_SIZE	(1024*4)
sl@0: #define OK_BLOCK_BLOCK	4
sl@0: #define IOBS		(OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE)
sl@0: #define WELLKNOWN "The quick brown fox jumped over the lazy dog's back."
sl@0: 
sl@0: typedef struct ok_struct
sl@0: 	{
sl@0: 	size_t buf_len;
sl@0: 	size_t buf_off;
sl@0: 	size_t buf_len_save;
sl@0: 	size_t buf_off_save;
sl@0: 	int cont;		/* <= 0 when finished */
sl@0: 	int finished;
sl@0: 	EVP_MD_CTX md;
sl@0: 	int blockout;		/* output block is ready */ 
sl@0: 	int sigio;		/* must process signature */
sl@0: 	unsigned char buf[IOBS];
sl@0: 	} BIO_OK_CTX;
sl@0: 
sl@0: #ifndef EMULATOR
sl@0: static BIO_METHOD methods_ok=
sl@0: 	{
sl@0: 	BIO_TYPE_CIPHER,"reliable",
sl@0: 	ok_write,
sl@0: 	ok_read,
sl@0: 	NULL, /* ok_puts, */
sl@0: 	NULL, /* ok_gets, */
sl@0: 	ok_ctrl,
sl@0: 	ok_new,
sl@0: 	ok_free,
sl@0: 	ok_callback_ctrl,
sl@0: 	};
sl@0: #else
sl@0: GET_STATIC_VAR_FROM_TLS(methods_ok,bio_ok,BIO_METHOD)
sl@0: #define methods_ok (*GET_WSD_VAR_NAME(methods_ok,bio_ok, s)())
sl@0: const BIO_METHOD temp_s_methods_ok=
sl@0: 	{
sl@0: 	BIO_TYPE_CIPHER,"reliable",
sl@0: 	ok_write,
sl@0: 	ok_read,
sl@0: 	NULL, /* ok_puts, */
sl@0: 	NULL, /* ok_gets, */
sl@0: 	ok_ctrl,
sl@0: 	ok_new,
sl@0: 	ok_free,
sl@0: 	ok_callback_ctrl,
sl@0: 	};
sl@0: 
sl@0: #endif	
sl@0: 
sl@0: EXPORT_C BIO_METHOD *BIO_f_reliable(void)
sl@0: 	{
sl@0: 	return(&methods_ok);
sl@0: 	}
sl@0: 
sl@0: static int ok_new(BIO *bi)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 
sl@0: 	ctx=(BIO_OK_CTX *)OPENSSL_malloc(sizeof(BIO_OK_CTX));
sl@0: 	if (ctx == NULL) return(0);
sl@0: 
sl@0: 	ctx->buf_len=0;
sl@0: 	ctx->buf_off=0;
sl@0: 	ctx->buf_len_save=0;
sl@0: 	ctx->buf_off_save=0;
sl@0: 	ctx->cont=1;
sl@0: 	ctx->finished=0;
sl@0: 	ctx->blockout= 0;
sl@0: 	ctx->sigio=1;
sl@0: 
sl@0: 	EVP_MD_CTX_init(&ctx->md);
sl@0: 
sl@0: 	bi->init=0;
sl@0: 	bi->ptr=(char *)ctx;
sl@0: 	bi->flags=0;
sl@0: 	return(1);
sl@0: 	}
sl@0: 
sl@0: static int ok_free(BIO *a)
sl@0: 	{
sl@0: 	if (a == NULL) return(0);
sl@0: 	EVP_MD_CTX_cleanup(&((BIO_OK_CTX *)a->ptr)->md);
sl@0: 	OPENSSL_cleanse(a->ptr,sizeof(BIO_OK_CTX));
sl@0: 	OPENSSL_free(a->ptr);
sl@0: 	a->ptr=NULL;
sl@0: 	a->init=0;
sl@0: 	a->flags=0;
sl@0: 	return(1);
sl@0: 	}
sl@0: 	
sl@0: static int ok_read(BIO *b, char *out, int outl)
sl@0: 	{
sl@0: 	int ret=0,i,n;
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 
sl@0: 	if (out == NULL) return(0);
sl@0: 	ctx=(BIO_OK_CTX *)b->ptr;
sl@0: 
sl@0: 	if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
sl@0: 
sl@0: 	while(outl > 0)
sl@0: 		{
sl@0: 
sl@0: 		/* copy clean bytes to output buffer */
sl@0: 		if (ctx->blockout)
sl@0: 			{
sl@0: 			i=ctx->buf_len-ctx->buf_off;
sl@0: 			if (i > outl) i=outl;
sl@0: 			memcpy(out,&(ctx->buf[ctx->buf_off]),i);
sl@0: 			ret+=i;
sl@0: 			out+=i;
sl@0: 			outl-=i;
sl@0: 			ctx->buf_off+=i;
sl@0: 
sl@0: 			/* all clean bytes are out */
sl@0: 			if (ctx->buf_len == ctx->buf_off)
sl@0: 				{
sl@0: 				ctx->buf_off=0;
sl@0: 
sl@0: 				/* copy start of the next block into proper place */
sl@0: 				if(ctx->buf_len_save- ctx->buf_off_save > 0)
sl@0: 					{
sl@0: 					ctx->buf_len= ctx->buf_len_save- ctx->buf_off_save;
sl@0: 					memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]),
sl@0: 							ctx->buf_len);
sl@0: 					}
sl@0: 				else
sl@0: 					{
sl@0: 					ctx->buf_len=0;
sl@0: 					}
sl@0: 				ctx->blockout= 0;
sl@0: 				}
sl@0: 			}
sl@0: 	
sl@0: 		/* output buffer full -- cancel */
sl@0: 		if (outl == 0) break;
sl@0: 
sl@0: 		/* no clean bytes in buffer -- fill it */
sl@0: 		n=IOBS- ctx->buf_len;
sl@0: 		i=BIO_read(b->next_bio,&(ctx->buf[ctx->buf_len]),n);
sl@0: 
sl@0: 		if (i <= 0) break;	/* nothing new */
sl@0: 
sl@0: 		ctx->buf_len+= i;
sl@0: 
sl@0: 		/* no signature yet -- check if we got one */
sl@0: 		if (ctx->sigio == 1) sig_in(b);
sl@0: 
sl@0: 		/* signature ok -- check if we got block */
sl@0: 		if (ctx->sigio == 0) block_in(b);
sl@0: 
sl@0: 		/* invalid block -- cancel */
sl@0: 		if (ctx->cont <= 0) break;
sl@0: 
sl@0: 		}
sl@0: 
sl@0: 	BIO_clear_retry_flags(b);
sl@0: 	BIO_copy_next_retry(b);
sl@0: 	return(ret);
sl@0: 	}
sl@0: 
sl@0: static int ok_write(BIO *b, const char *in, int inl)
sl@0: 	{
sl@0: 	int ret=0,n,i;
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 
sl@0: 	if (inl <= 0) return inl;
sl@0: 
sl@0: 	ctx=(BIO_OK_CTX *)b->ptr;
sl@0: 	ret=inl;
sl@0: 
sl@0: 	if ((ctx == NULL) || (b->next_bio == NULL) || (b->init == 0)) return(0);
sl@0: 
sl@0: 	if(ctx->sigio) sig_out(b);
sl@0: 
sl@0: 	do{
sl@0: 		BIO_clear_retry_flags(b);
sl@0: 		n=ctx->buf_len-ctx->buf_off;
sl@0: 		while (ctx->blockout && n > 0)
sl@0: 			{
sl@0: 			i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
sl@0: 			if (i <= 0)
sl@0: 				{
sl@0: 				BIO_copy_next_retry(b);
sl@0: 				if(!BIO_should_retry(b))
sl@0: 					ctx->cont= 0;
sl@0: 				return(i);
sl@0: 				}
sl@0: 			ctx->buf_off+=i;
sl@0: 			n-=i;
sl@0: 			}
sl@0: 
sl@0: 		/* at this point all pending data has been written */
sl@0: 		ctx->blockout= 0;
sl@0: 		if (ctx->buf_len == ctx->buf_off)
sl@0: 			{
sl@0: 			ctx->buf_len=OK_BLOCK_BLOCK;
sl@0: 			ctx->buf_off=0;
sl@0: 			}
sl@0: 	
sl@0: 		if ((in == NULL) || (inl <= 0)) return(0);
sl@0: 
sl@0: 		n= (inl+ ctx->buf_len > OK_BLOCK_SIZE+ OK_BLOCK_BLOCK) ? 
sl@0: 			(int)(OK_BLOCK_SIZE+OK_BLOCK_BLOCK-ctx->buf_len) : inl;
sl@0: 
sl@0: 		memcpy((unsigned char *)(&(ctx->buf[ctx->buf_len])),(unsigned char *)in,n);
sl@0: 		ctx->buf_len+= n;
sl@0: 		inl-=n;
sl@0: 		in+=n;
sl@0: 
sl@0: 		if(ctx->buf_len >= OK_BLOCK_SIZE+ OK_BLOCK_BLOCK)
sl@0: 			{
sl@0: 			block_out(b);
sl@0: 			}
sl@0: 	}while(inl > 0);
sl@0: 
sl@0: 	BIO_clear_retry_flags(b);
sl@0: 	BIO_copy_next_retry(b);
sl@0: 	return(ret);
sl@0: 	}
sl@0: 
sl@0: static long ok_ctrl(BIO *b, int cmd, long num, void *ptr)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 	EVP_MD *md;
sl@0: 	const EVP_MD **ppmd;
sl@0: 	long ret=1;
sl@0: 	int i;
sl@0: 
sl@0: 	ctx=b->ptr;
sl@0: 
sl@0: 	switch (cmd)
sl@0: 		{
sl@0: 	case BIO_CTRL_RESET:
sl@0: 		ctx->buf_len=0;
sl@0: 		ctx->buf_off=0;
sl@0: 		ctx->buf_len_save=0;
sl@0: 		ctx->buf_off_save=0;
sl@0: 		ctx->cont=1;
sl@0: 		ctx->finished=0;
sl@0: 		ctx->blockout= 0;
sl@0: 		ctx->sigio=1;
sl@0: 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		break;
sl@0: 	case BIO_CTRL_EOF:	/* More to read */
sl@0: 		if (ctx->cont <= 0)
sl@0: 			ret=1;
sl@0: 		else
sl@0: 			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		break;
sl@0: 	case BIO_CTRL_PENDING: /* More to read in buffer */
sl@0: 	case BIO_CTRL_WPENDING: /* More to read in buffer */
sl@0: 		ret=ctx->blockout ? ctx->buf_len-ctx->buf_off : 0;
sl@0: 		if (ret <= 0)
sl@0: 			ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		break;
sl@0: 	case BIO_CTRL_FLUSH:
sl@0: 		/* do a final write */
sl@0: 		if(ctx->blockout == 0)
sl@0: 			block_out(b);
sl@0: 
sl@0: 		while (ctx->blockout)
sl@0: 			{
sl@0: 			i=ok_write(b,NULL,0);
sl@0: 			if (i < 0)
sl@0: 				{
sl@0: 				ret=i;
sl@0: 				break;
sl@0: 				}
sl@0: 			}
sl@0: 
sl@0: 		ctx->finished=1;
sl@0: 		ctx->buf_off=ctx->buf_len=0;
sl@0: 		ctx->cont=(int)ret;
sl@0: 		
sl@0: 		/* Finally flush the underlying BIO */
sl@0: 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		break;
sl@0: 	case BIO_C_DO_STATE_MACHINE:
sl@0: 		BIO_clear_retry_flags(b);
sl@0: 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		BIO_copy_next_retry(b);
sl@0: 		break;
sl@0: 	case BIO_CTRL_INFO:
sl@0: 		ret=(long)ctx->cont;
sl@0: 		break;
sl@0: 	case BIO_C_SET_MD:
sl@0: 		md=ptr;
sl@0: 		EVP_DigestInit_ex(&ctx->md, md, NULL);
sl@0: 		b->init=1;
sl@0: 		break;
sl@0: 	case BIO_C_GET_MD:
sl@0: 		if (b->init)
sl@0: 			{
sl@0: 			ppmd=ptr;
sl@0: 			*ppmd=ctx->md.digest;
sl@0: 			}
sl@0: 		else
sl@0: 			ret=0;
sl@0: 		break;
sl@0: 	default:
sl@0: 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
sl@0: 		break;
sl@0: 		}
sl@0: 	return(ret);
sl@0: 	}
sl@0: 
sl@0: static long ok_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
sl@0: 	{
sl@0: 	long ret=1;
sl@0: 
sl@0: 	if (b->next_bio == NULL) return(0);
sl@0: 	switch (cmd)
sl@0: 		{
sl@0: 	default:
sl@0: 		ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
sl@0: 		break;
sl@0: 		}
sl@0: 	return(ret);
sl@0: 	}
sl@0: 
sl@0: static void longswap(void *_ptr, size_t len)
sl@0: {	const union { long one; char little; } is_endian = {1};
sl@0: 
sl@0: 	if (is_endian.little) {
sl@0: 		size_t i;
sl@0: 		unsigned char *p=_ptr,c;
sl@0: 
sl@0: 		for(i= 0;i < len;i+= 4) {
sl@0: 			c=p[0],p[0]=p[3],p[3]=c;
sl@0: 			c=p[1],p[1]=p[2],p[2]=c;
sl@0: 		}
sl@0: 	}
sl@0: }
sl@0: 
sl@0: static void sig_out(BIO* b)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 	EVP_MD_CTX *md;
sl@0: 
sl@0: 	ctx=b->ptr;
sl@0: 	md=&ctx->md;
sl@0: 
sl@0: 	if(ctx->buf_len+ 2* md->digest->md_size > OK_BLOCK_SIZE) return;
sl@0: 
sl@0: 	EVP_DigestInit_ex(md, md->digest, NULL);
sl@0: 	/* FIXME: there's absolutely no guarantee this makes any sense at all,
sl@0: 	 * particularly now EVP_MD_CTX has been restructured.
sl@0: 	 */
sl@0: 	RAND_pseudo_bytes(md->md_data, md->digest->md_size);
sl@0: 	memcpy(&(ctx->buf[ctx->buf_len]), md->md_data, md->digest->md_size);
sl@0: 	longswap(&(ctx->buf[ctx->buf_len]), md->digest->md_size);
sl@0: 	ctx->buf_len+= md->digest->md_size;
sl@0: 
sl@0: 	EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
sl@0: 	EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL);
sl@0: 	ctx->buf_len+= md->digest->md_size;
sl@0: 	ctx->blockout= 1;
sl@0: 	ctx->sigio= 0;
sl@0: 	}
sl@0: 
sl@0: static void sig_in(BIO* b)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 	EVP_MD_CTX *md;
sl@0: 	unsigned char tmp[EVP_MAX_MD_SIZE];
sl@0: 	int ret= 0;
sl@0: 
sl@0: 	ctx=b->ptr;
sl@0: 	md=&ctx->md;
sl@0: 
sl@0: 	if((int)(ctx->buf_len-ctx->buf_off) < 2*md->digest->md_size) return;
sl@0: 
sl@0: 	EVP_DigestInit_ex(md, md->digest, NULL);
sl@0: 	memcpy(md->md_data, &(ctx->buf[ctx->buf_off]), md->digest->md_size);
sl@0: 	longswap(md->md_data, md->digest->md_size);
sl@0: 	ctx->buf_off+= md->digest->md_size;
sl@0: 
sl@0: 	EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN));
sl@0: 	EVP_DigestFinal_ex(md, tmp, NULL);
sl@0: 	ret= memcmp(&(ctx->buf[ctx->buf_off]), tmp, md->digest->md_size) == 0;
sl@0: 	ctx->buf_off+= md->digest->md_size;
sl@0: 	if(ret == 1)
sl@0: 		{
sl@0: 		ctx->sigio= 0;
sl@0: 		if(ctx->buf_len != ctx->buf_off)
sl@0: 			{
sl@0: 			memmove(ctx->buf, &(ctx->buf[ctx->buf_off]), ctx->buf_len- ctx->buf_off);
sl@0: 			}
sl@0: 		ctx->buf_len-= ctx->buf_off;
sl@0: 		ctx->buf_off= 0;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		ctx->cont= 0;
sl@0: 		}
sl@0: 	}
sl@0: 
sl@0: static void block_out(BIO* b)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 	EVP_MD_CTX *md;
sl@0: 	unsigned long tl;
sl@0: 
sl@0: 	ctx=b->ptr;
sl@0: 	md=&ctx->md;
sl@0: 
sl@0: 	tl= ctx->buf_len- OK_BLOCK_BLOCK;
sl@0: 	ctx->buf[0]=(unsigned char)(tl>>24);
sl@0: 	ctx->buf[1]=(unsigned char)(tl>>16);
sl@0: 	ctx->buf[2]=(unsigned char)(tl>>8);
sl@0: 	ctx->buf[3]=(unsigned char)(tl);
sl@0: 	EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl);
sl@0: 	EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL);
sl@0: 	ctx->buf_len+= md->digest->md_size;
sl@0: 	ctx->blockout= 1;
sl@0: 	}
sl@0: 
sl@0: static void block_in(BIO* b)
sl@0: 	{
sl@0: 	BIO_OK_CTX *ctx;
sl@0: 	EVP_MD_CTX *md;
sl@0: 	unsigned long tl= 0;
sl@0: 	unsigned char tmp[EVP_MAX_MD_SIZE];
sl@0: 
sl@0: 	ctx=b->ptr;
sl@0: 	md=&ctx->md;
sl@0: 
sl@0: 	assert(sizeof(tl)>=OK_BLOCK_BLOCK);	/* always true */
sl@0: 	tl =ctx->buf[0]; tl<<=8;
sl@0: 	tl|=ctx->buf[1]; tl<<=8;
sl@0: 	tl|=ctx->buf[2]; tl<<=8;
sl@0: 	tl|=ctx->buf[3];
sl@0: 
sl@0: 	if (ctx->buf_len < tl+ OK_BLOCK_BLOCK+ md->digest->md_size) return;
sl@0:  
sl@0: 	EVP_DigestUpdate(md, (unsigned char*) &(ctx->buf[OK_BLOCK_BLOCK]), tl);
sl@0: 	EVP_DigestFinal_ex(md, tmp, NULL);
sl@0: 	if(memcmp(&(ctx->buf[tl+ OK_BLOCK_BLOCK]), tmp, md->digest->md_size) == 0)
sl@0: 		{
sl@0: 		/* there might be parts from next block lurking around ! */
sl@0: 		ctx->buf_off_save= tl+ OK_BLOCK_BLOCK+ md->digest->md_size;
sl@0: 		ctx->buf_len_save= ctx->buf_len;
sl@0: 		ctx->buf_off= OK_BLOCK_BLOCK;
sl@0: 		ctx->buf_len= tl+ OK_BLOCK_BLOCK;
sl@0: 		ctx->blockout= 1;
sl@0: 		}
sl@0: 	else
sl@0: 		{
sl@0: 		ctx->cont= 0;
sl@0: 		}
sl@0: 	}
sl@0: