/* crypto/asn1/a_bitstr.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/asn1.h>

EXPORT_C int ASN1_BIT_STRING_set(ASN1_BIT_STRING *x, unsigned char *d, int len)

{ return M_ASN1_BIT_STRING_set(x, d, len); }

EXPORT_C int i2c_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **pp)

	{

	int ret,j,bits,len;

	unsigned char *p,*d;

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

	len=a->length;

	if (len > 0)

		{

		if (a->flags & ASN1_STRING_FLAG_BITS_LEFT)

			{

			bits=(int)a->flags&0x07;

			}

		else

			{

			for ( ; len > 0; len--)

				{

				if (a->data[len-1]) break;

				}

			j=a->data[len-1];

			if      (j & 0x01) bits=0;

			else if (j & 0x02) bits=1;

			else if (j & 0x04) bits=2;

			else if (j & 0x08) bits=3;

			else if (j & 0x10) bits=4;

			else if (j & 0x20) bits=5;

			else if (j & 0x40) bits=6;

			else if (j & 0x80) bits=7;

			else bits=0; /* should not happen */

			}

		}

	else

		bits=0;

	ret=1+len;

	if (pp == NULL) return(ret);

	p= *pp;

	*(p++)=(unsigned char)bits;

	d=a->data;

	memcpy(p,d,len);

	p+=len;

	if (len > 0) p[-1]&=(0xff<<bits);

	*pp=p;

	return(ret);

	}

EXPORT_C ASN1_BIT_STRING *c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a,

	const unsigned char **pp, long len)

	{

	ASN1_BIT_STRING *ret=NULL;

	const unsigned char *p;

	unsigned char *s;

	int i;

	if (len < 1)

		{

		i=ASN1_R_STRING_TOO_SHORT;

		goto err;

		}

	if ((a == NULL) || ((*a) == NULL))

		{

		if ((ret=M_ASN1_BIT_STRING_new()) == NULL) return(NULL);

		}

	else

		ret=(*a);

	p= *pp;

	i= *(p++);

	/* We do this to preserve the settings.  If we modify

	 * the settings, via the _set_bit function, we will recalculate

	 * on output */

	ret->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear */

	ret->flags|=(ASN1_STRING_FLAG_BITS_LEFT|(i&0x07)); /* set */

	if (len-- > 1) /* using one because of the bits left byte */

		{

		s=(unsigned char *)OPENSSL_malloc((int)len);

		if (s == NULL)

			{

			i=ERR_R_MALLOC_FAILURE;

			goto err;

			}

		memcpy(s,p,(int)len);

		s[len-1]&=(0xff<<i);

		p+=len;

		}

	else

		s=NULL;

	ret->length=(int)len;

	if (ret->data != NULL) OPENSSL_free(ret->data);

	ret->data=s;

	ret->type=V_ASN1_BIT_STRING;

	if (a != NULL) (*a)=ret;

	*pp=p;

	return(ret);

err:

	ASN1err(ASN1_F_C2I_ASN1_BIT_STRING,i);

	if ((ret != NULL) && ((a == NULL) || (*a != ret)))

		M_ASN1_BIT_STRING_free(ret);

	return(NULL);

	}

/* These next 2 functions from Goetz Babin-Ebell <babinebell@trustcenter.de>

 */

EXPORT_C int ASN1_BIT_STRING_set_bit(ASN1_BIT_STRING *a, int n, int value)

	{

	int w,v,iv;

	unsigned char *c;

	w=n/8;

	v=1<<(7-(n&0x07));

	iv= ~v;

	if (!value) v=0;

	if (a == NULL)

		return 0;

	a->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07); /* clear, set on write */

	if ((a->length < (w+1)) || (a->data == NULL))

		{

		if (!value) return(1); /* Don't need to set */

		if (a->data == NULL)

			c=(unsigned char *)OPENSSL_malloc(w+1);

		else

			c=(unsigned char *)OPENSSL_realloc_clean(a->data,

								 a->length,

								 w+1);

		if (c == NULL)

			{

			ASN1err(ASN1_F_ASN1_BIT_STRING_SET_BIT,ERR_R_MALLOC_FAILURE);

			return 0;

			}

  		if (w+1-a->length > 0) memset(c+a->length, 0, w+1-a->length);

		a->data=c;

		a->length=w+1;

	}

	a->data[w]=((a->data[w])&iv)|v;

	while ((a->length > 0) && (a->data[a->length-1] == 0))

		a->length--;

	return(1);

	}

EXPORT_C int ASN1_BIT_STRING_get_bit(ASN1_BIT_STRING *a, int n)

	{

	int w,v;

	w=n/8;

	v=1<<(7-(n&0x07));

	if ((a == NULL) || (a->length < (w+1)) || (a->data == NULL))

		return(0);

	return((a->data[w]&v) != 0);

	}