/* $OpenBSD: a_bitstr.c,v 1.36 2022/05/17 09:17:20 tb Exp $ */

/* 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 <string.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/conf.h>

#include <openssl/err.h>

#include <openssl/x509v3.h>

#include "bytestring.h"

const ASN1_ITEM ASN1_BIT_STRING_it = {

  .itype = ASN1_ITYPE_PRIMITIVE,

  .utype = V_ASN1_BIT_STRING,

  .sname = "ASN1_BIT_STRING",

};

ASN1_BIT_STRING *

ASN1_BIT_STRING_new(void)

{

  return (ASN1_BIT_STRING *)ASN1_item_new(&ASN1_BIT_STRING_it);

}

void

ASN1_BIT_STRING_free(ASN1_BIT_STRING *a)

{

  ASN1_item_free((ASN1_VALUE *)a, &ASN1_BIT_STRING_it);

}

static void

asn1_abs_clear_unused_bits(ASN1_BIT_STRING *abs)

{

  abs->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07);

}

int

asn1_abs_set_unused_bits(ASN1_BIT_STRING *abs, uint8_t unused_bits)

{

  if (unused_bits > 7)

    return 0;

  asn1_abs_clear_unused_bits(abs);

  abs->flags |= ASN1_STRING_FLAG_BITS_LEFT | unused_bits;

  return 1;

}

int

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

{

  return ASN1_STRING_set(x, d, len);

}

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;

  asn1_abs_clear_unused_bits(a);

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

    if (!value)

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

    if ((c = recallocarray(a->data, a->length, w + 1, 1)) == NULL) {

      ASN1error(ERR_R_MALLOC_FAILURE);

      return 0;

    }

    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(const 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(const ASN1_BIT_STRING *a, const 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;

}

int

ASN1_BIT_STRING_name_print(BIO *out, ASN1_BIT_STRING *bs,

    BIT_STRING_BITNAME *tbl, int indent)

{

  BIT_STRING_BITNAME *bnam;

  char first = 1;

  BIO_printf(out, "%*s", indent, "");

  for (bnam = tbl; bnam->lname; bnam++) {

    if (ASN1_BIT_STRING_get_bit(bs, bnam->bitnum)) {

      if (!first)

        BIO_puts(out, ", ");

      BIO_puts(out, bnam->lname);

      first = 0;

    }

  }

  BIO_puts(out, "\n");

  return 1;

}

int

ASN1_BIT_STRING_set_asc(ASN1_BIT_STRING *bs, const char *name, int value,

    BIT_STRING_BITNAME *tbl)

{

  int bitnum;

  bitnum = ASN1_BIT_STRING_num_asc(name, tbl);

  if (bitnum < 0)

    return 0;

  if (bs) {

    if (!ASN1_BIT_STRING_set_bit(bs, bitnum, value))

      return 0;

  }

  return 1;

}

int

ASN1_BIT_STRING_num_asc(const char *name, BIT_STRING_BITNAME *tbl)

{

  BIT_STRING_BITNAME *bnam;

  for (bnam = tbl; bnam->lname; bnam++) {

    if (!strcmp(bnam->sname, name) ||

        !strcmp(bnam->lname, name))

      return bnam->bitnum;

  }

  return -1;

}

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);

}

int

c2i_ASN1_BIT_STRING_cbs(ASN1_BIT_STRING **out_abs, CBS *cbs)

{

  ASN1_BIT_STRING *abs = NULL;

  uint8_t *data = NULL;

  size_t data_len = 0;

  uint8_t unused_bits;

  int ret = 0;

  if (out_abs == NULL)

    goto err;

  if (*out_abs != NULL) {

    ASN1_BIT_STRING_free(*out_abs);

    *out_abs = NULL;

  }

  if (!CBS_get_u8(cbs, &unused_bits)) {

    ASN1error(ASN1_R_STRING_TOO_SHORT);

    goto err;

  }

  if (!CBS_stow(cbs, &data, &data_len))

    goto err;

  if (data_len > INT_MAX)

    goto err;

  if ((abs = ASN1_BIT_STRING_new()) == NULL)

    goto err;

  abs->data = data;

  abs->length = (int)data_len;

  data = NULL;

  /*

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

   * via the _set_bit function, we will recalculate on output.

   */

  if (!asn1_abs_set_unused_bits(abs, unused_bits)) {

    ASN1error(ASN1_R_INVALID_BIT_STRING_BITS_LEFT);

    goto err;

  }

  if (abs->length > 0)

    abs->data[abs->length - 1] &= 0xff << unused_bits;

  *out_abs = abs;

  abs = NULL;

  ret = 1;

 err:

  ASN1_BIT_STRING_free(abs);

  freezero(data, data_len);

  return ret;

}

ASN1_BIT_STRING *

c2i_ASN1_BIT_STRING(ASN1_BIT_STRING **out_abs, const unsigned char **pp, long len)

{

  ASN1_BIT_STRING *abs = NULL;

  CBS content;

  if (out_abs != NULL) {

    ASN1_BIT_STRING_free(*out_abs);

    *out_abs = NULL;

  }

  if (len < 0) {

    ASN1error(ASN1_R_LENGTH_ERROR);

    return NULL;

  }

  CBS_init(&content, *pp, len);

  if (!c2i_ASN1_BIT_STRING_cbs(&abs, &content))

    return NULL;

  *pp = CBS_data(&content);

  if (out_abs != NULL)

    *out_abs = abs;

  return abs;

}

int

i2d_ASN1_BIT_STRING(ASN1_BIT_STRING *a, unsigned char **out)

{

  return ASN1_item_i2d((ASN1_VALUE *)a, out, &ASN1_BIT_STRING_it);

}

ASN1_BIT_STRING *

d2i_ASN1_BIT_STRING(ASN1_BIT_STRING **a, const unsigned char **in, long len)

{

  return (ASN1_BIT_STRING *)ASN1_item_d2i((ASN1_VALUE **)a, in, len,

      &ASN1_BIT_STRING_it);

}