text: ﻿/* crypto/evp/bio_ber.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 <errno.h>
  #include "cryptlib.h"
  #include <openssl/buffer.h>
  #include <openssl/evp.h>
  
  static int ber_write(BIO *h,char *buf,int num);
  static int ber_read(BIO *h,char *buf,int size);
  /*static int ber_puts(BIO *h,char *str); */
  /*static int ber_gets(BIO *h,char *str,int size); */
  static long ber_ctrl(BIO *h,int cmd,long arg1,char *arg2);
  static int ber_new(BIO *h);
  static int ber_free(BIO *data);
  static long ber_callback_ctrl(BIO *h,int cmd,void *(*fp)());
  #define BER_BUF_SIZE	(32)
  
  /* This is used to hold the state of the BER objects being read. */
  typedef struct ber_struct
  	{
  	int tag;
  	int class;
  	long length;
  	int inf;
  	int num_left;
  	int depth;
  	} BER_CTX;
  
  typedef struct bio_ber_struct
  	{
  	int tag;
  	int class;
  	long length;
  	int inf;
  
  	/* most of the following are used when doing non-blocking IO */
  	/* reading */
  	long num_left;	/* number of bytes still to read/write in block */
  	int depth;	/* used with indefinite encoding. */
  	int finished;	/* No more read data */
  
  	/* writting */ 
  	char *w_addr;
  	int w_offset;
  	int w_left;
  
  	int buf_len;
  	int buf_off;
  	unsigned char buf[BER_BUF_SIZE];
  	} BIO_BER_CTX;
  
  static BIO_METHOD methods_ber=
  	{
  	BIO_TYPE_CIPHER,"cipher",
  	ber_write,
  	ber_read,
  	NULL, /* ber_puts, */
  	NULL, /* ber_gets, */
  	ber_ctrl,
  	ber_new,
  	ber_free,
  	ber_callback_ctrl,
  	};
  
  BIO_METHOD *BIO_f_ber(void)
  	{
  	return(&methods_ber);
  	}
  
  static int ber_new(BIO *bi)
  	{
  	BIO_BER_CTX *ctx;
  
  	ctx=(BIO_BER_CTX *)OPENSSL_malloc(sizeof(BIO_BER_CTX));
  	if (ctx == NULL) return(0);
  
  	memset((char *)ctx,0,sizeof(BIO_BER_CTX));
  
  	bi->init=0;
  	bi->ptr=(char *)ctx;
  	bi->flags=0;
  	return(1);
  	}
  
  static int ber_free(BIO *a)
  	{
  	BIO_BER_CTX *b;
  
  	if (a == NULL) return(0);
  	b=(BIO_BER_CTX *)a->ptr;
  	OPENSSL_cleanse(a->ptr,sizeof(BIO_BER_CTX));
  	OPENSSL_free(a->ptr);
  	a->ptr=NULL;
  	a->init=0;
  	a->flags=0;
  	return(1);
  	}
  
  int bio_ber_get_header(BIO *bio, BIO_BER_CTX *ctx)
  	{
  	char buf[64];
  	int i,j,n;
  	int ret;
  	unsigned char *p;
  	unsigned long length
  	int tag;
  	int class;
  	long max;
  
  	BIO_clear_retry_flags(b);
  
  	/* Pack the buffer down if there is a hole at the front */
  	if (ctx->buf_off != 0)
  		{
  		p=ctx->buf;
  		j=ctx->buf_off;
  		n=ctx->buf_len-j;
  		for (i=0; i<n; i++)
  			{
  			p[0]=p[j];
  			p++;
  			}
  		ctx->buf_len-j;
  		ctx->buf_off=0;
  		}
  
  	/* If there is more room, read some more data */
  	i=BER_BUF_SIZE-ctx->buf_len;
  	if (i)
  		{
  		i=BIO_read(bio->next_bio,&(ctx->buf[ctx->buf_len]),i);
  		if (i <= 0)
  			{
  			BIO_copy_next_retry(b);
  			return(i);
  			}
  		else
  			ctx->buf_len+=i;
  		}
  
  	max=ctx->buf_len;
  	p=ctx->buf;
  	ret=ASN1_get_object(&p,&length,&tag,&class,max);
  
  	if (ret & 0x80)
  		{
  		if ((ctx->buf_len < BER_BUF_SIZE) &&
  			(ERR_GET_REASON(ERR_peek_error()) == ASN1_R_TOO_LONG))
  			{
  			ERR_clear_error(); /* clear the error */
  			BIO_set_retry_read(b);
  			}
  		return(-1);
  		}
  
  	/* We have no error, we have a header, so make use of it */
  
  	if ((ctx->tag  >= 0) && (ctx->tag != tag))
  		{
  		BIOerr(BIO_F_BIO_BER_GET_HEADER,BIO_R_TAG_MISMATCH);
  		sprintf(buf,"tag=%d, got %d",ctx->tag,tag);
  		ERR_add_error_data(1,buf);
  		return(-1);
  		}
  	if (ret & 0x01)
  	if (ret & V_ASN1_CONSTRUCTED)
  	}
  	
  static int ber_read(BIO *b, char *out, int outl)
  	{
  	int ret=0,i,n;
  	BIO_BER_CTX *ctx;
  
  	BIO_clear_retry_flags(b);
  
  	if (out == NULL) return(0);
  	ctx=(BIO_BER_CTX *)b->ptr;
  
  	if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
  
  	if (ctx->finished) return(0);
  
  again:
  	/* First see if we are half way through reading a block */
  	if (ctx->num_left > 0)
  		{
  		if (ctx->num_left < outl)
  			n=ctx->num_left;
  		else
  			n=outl;
  		i=BIO_read(b->next_bio,out,n);
  		if (i <= 0)
  			{
  			BIO_copy_next_retry(b);
  			return(i);
  			}
  		ctx->num_left-=i;
  		outl-=i;
  		ret+=i;
  		if (ctx->num_left <= 0)
  			{
  			ctx->depth--;
  			if (ctx->depth <= 0)
  				ctx->finished=1;
  			}
  		if (outl <= 0)
  			return(ret);
  		else
  			goto again;
  		}
  	else	/* we need to read another BER header */
  		{
  		}
  	}
  
  static int ber_write(BIO *b, 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(i);
  				}
  			n-=i;
  			ctx->buf_off+=i;
  			}
  		ctx->buf_len=0;
  		ctx->buf_off=0;
  		}
  	BIO_copy_next_retry(b);
  	return(ret);
  	}
  
  static long ber_ctrl(BIO *b, int cmd, long num, char *ptr)
  	{
  	BIO *dbio;
  	BIO_ENC_CTX *ctx,*dctx;
  	long ret=1;
  	int i;
  
  	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.berrypt);
  		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=ber_write(b,NULL,0);
  			if (i < 0)
  				{
  				ret=i;
  				break;
  				}
  			}
  
  		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_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 ber_callback_ctrl(BIO *b, int cmd, void *(*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);
  	}
  */
  
  void BIO_set_cipher(BIO *b, EVP_CIPHER *c, unsigned char *k, unsigned char *i,
  	     int e)
  	{
  	BIO_ENC_CTX *ctx;
  
  	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;
  	EVP_CipherInit_ex(&(ctx->cipher),c,NULL,k,i,e);
  	
  	if (b->callback != NULL)
  		b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
  	}
  
  