/* 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 <limits.h>

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/asn1.h>

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

{

    return M_ASN1_BIT_STRING_set(x, d, len);

}

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;

    if (len > 0) {

        memcpy(p, d, len);

        p += len;

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

    }

    *pp = p;

    return (ret);

}

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 (len > INT_MAX) {

        i = ASN1_R_STRING_TOO_LONG;

        goto err;

    }

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

        if ((ret = M_ASN1_BIT_STRING_new()) == NULL)

            return (NULL);

    } else

        ret = (*a);

    p = *pp;

    i = *(p++);

    if (i > 7) {

        i = ASN1_R_INVALID_BIT_STRING_BITS_LEFT;

        goto err;

    }

    /*

     * 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); /* 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>

 */

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);

}

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);

}

/*

 * Checks if the given bit string contains only bits specified by

 * the flags vector. Returns 0 if there is at least one bit set in 'a'

 * which is not specified in 'flags', 1 otherwise.

 * 'len' is the length of 'flags'.

 */

int ASN1_BIT_STRING_check(ASN1_BIT_STRING *a,

                          unsigned char *flags, int flags_len)

{

    int i, ok;

    /* Check if there is one bit set at all. */

    if (!a || !a->data)

        return 1;

    /*

     * Check each byte of the internal representation of the bit string.

     */

    ok = 1;

    for (i = 0; i < a->length && ok; ++i) {

        unsigned char mask = i < flags_len ? ~flags[i] : 0xff;

        /* We are done if there is an unneeded bit set. */

        ok = (a->data[i] & mask) == 0;

    }

    return ok;

}