/*

   Unix SMB/CIFS implementation.

   Easy management of byte-length data

   Copyright (C) Andrew Tridgell 2001

   Copyright (C) Andrew Bartlett 2001

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "replace.h"

#include "attr.h"

#include "data_blob.h"

#include "lib/util/samba_util.h"

#include "lib/util/tsort.h"

const DATA_BLOB data_blob_null = { NULL, 0 };

/**

 * @file

 * @brief Manipulation of arbitrary data blobs

 **/

/**

 construct a data blob, must be freed with data_blob_free()

 you can pass NULL for p and get a blank data blob

**/

_PUBLIC_ DATA_BLOB data_blob_named(const void *p, size_t length, const char *name)

{

  return data_blob_talloc_named(NULL, p, length, name);

}

/**

 construct a data blob, using supplied TALLOC_CTX

**/

_PUBLIC_ DATA_BLOB data_blob_talloc_named(TALLOC_CTX *mem_ctx, const void *p, size_t length, const char *name)

{

  DATA_BLOB ret;

  if (p == NULL && length == 0) {

    ZERO_STRUCT(ret);

    return ret;

  }

  if (p) {

    ret.data = (uint8_t *)talloc_memdup(mem_ctx, p, length);

  } else {

    ret.data = talloc_array(mem_ctx, uint8_t, length);

  }

  if (ret.data == NULL) {

    ret.length = 0;

    return ret;

  }

  talloc_set_name_const(ret.data, name);

  ret.length = length;

  return ret;

}

/**

 construct a zero data blob, using supplied TALLOC_CTX.

 use this sparingly as it initialises data - better to initialise

 yourself if you want specific data in the blob

**/

_PUBLIC_ DATA_BLOB data_blob_talloc_zero(TALLOC_CTX *mem_ctx, size_t length)

{

  DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, length);

  data_blob_clear(&blob);

  return blob;

}

/**

free a data blob

**/

_PUBLIC_ void data_blob_free(DATA_BLOB *d)

{

  if (d) {

    TALLOC_FREE(d->data);

    d->length = 0;

  }

}

/**

clear a DATA_BLOB's contents

**/

_PUBLIC_ void data_blob_clear(DATA_BLOB *d)

{

  if (d->data) {

    ZERO_ARRAY_LEN(d->data, d->length);

  }

}

/**

free a data blob and clear its contents

**/

_PUBLIC_ void data_blob_clear_free(DATA_BLOB *d)

{

  data_blob_clear(d);

  data_blob_free(d);

}

/**

check if two data blobs are equal

**/

_PUBLIC_ int data_blob_cmp(const DATA_BLOB *d1, const DATA_BLOB *d2)

{

  int ret;

  if (d1->data == NULL && d2->data != NULL) {

    return -1;

  }

  if (d1->data != NULL && d2->data == NULL) {

    return 1;

  }

  if (d1->data == d2->data) {

    return NUMERIC_CMP(d1->length, d2->length);

  }

  ret = memcmp(d1->data, d2->data, MIN(d1->length, d2->length));

  if (ret == 0) {

    /* Note this ordering is used in conditional aces */

    return NUMERIC_CMP(d1->length, d2->length);

  }

  return ret;

}

/**

check if two data blobs are equal, where the time taken should not depend on the

contents of either blob.

**/

_PUBLIC_ bool data_blob_equal_const_time(const DATA_BLOB *d1, const DATA_BLOB *d2)

{

  bool ret;

  if (d1->data == NULL && d2->data != NULL) {

    return false;

  }

  if (d1->data != NULL && d2->data == NULL) {

    return false;

  }

  if (d1->length != d2->length) {

    return false;

  }

  if (d1->data == d2->data) {

    return true;

  }

  ret = mem_equal_const_time(d1->data, d2->data, d1->length);

  return ret;

}

/**

print the data_blob as hex string

**/

_PUBLIC_ char *data_blob_hex_string_lower(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob)

{

  size_t i;

  char *hex_string;

  hex_string = talloc_array(mem_ctx, char, (blob->length*2)+1);

  if (!hex_string) {

    return NULL;

  }

  /* this must be lowercase or w2k8 cannot join a samba domain,

     as this routine is used to encode extended DNs and windows

     only accepts lowercase hexadecimal numbers */

  for (i = 0; i < blob->length; i++) {

    hex_string[i * 2] = nybble_to_hex_lower(blob->data[i] >> 4);

    hex_string[i * 2 + 1] = nybble_to_hex_lower(blob->data[i]);

  }

  hex_string[(blob->length*2)] = '\0';

  return hex_string;

}

_PUBLIC_ char *data_blob_hex_string_upper(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob)

{

  size_t i;

  char *hex_string;

  hex_string = talloc_array(mem_ctx, char, (blob->length*2)+1);

  if (!hex_string) {

    return NULL;

  }

  for (i = 0; i < blob->length; i++) {

    hex_string[i * 2] = nybble_to_hex_upper(blob->data[i] >> 4);

    hex_string[i * 2 + 1] = nybble_to_hex_upper(blob->data[i]);

  }

  hex_string[(blob->length*2)] = '\0';

  return hex_string;

}

/**

  useful for constructing data blobs in test suites, while

  avoiding const warnings

**/

_PUBLIC_ DATA_BLOB data_blob_string_const(const char *str)

{

  DATA_BLOB blob;

  blob.data = discard_const_p(uint8_t, str);

  blob.length = str ? strlen(str) : 0;

  return blob;

}

/**

  useful for constructing data blobs in test suites, while

  avoiding const warnings

**/

_PUBLIC_ DATA_BLOB data_blob_string_const_null(const char *str)

{

  DATA_BLOB blob;

  blob.data = discard_const_p(uint8_t, str);

  blob.length = str ? strlen(str)+1 : 0;

  return blob;

}

/**

 * Create a new data blob from const data

 */

_PUBLIC_ DATA_BLOB data_blob_const(const void *p, size_t length)

{

  DATA_BLOB blob;

  blob.data = discard_const_p(uint8_t, p);

  blob.length = length;

  return blob;

}

/**

  realloc a data_blob

**/

_PUBLIC_ bool data_blob_realloc(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, size_t length)

{

  uint8_t *tmp = talloc_realloc(mem_ctx, blob->data, uint8_t, length);

  if (tmp == NULL) {

    return false;

  }

  blob->data = tmp;

  blob->length = length;

  return true;

}

/**

  append some data to a data blob

**/

_PUBLIC_ bool data_blob_append(TALLOC_CTX *mem_ctx, DATA_BLOB *blob,

           const void *p, size_t length)

{

  size_t old_len = blob->length;

  size_t new_len = old_len + length;

  if (length == 0) {

    return true;

  }

  if (new_len < length || new_len < old_len) {

    return false;

  }

  if ((const uint8_t *)p + length < (const uint8_t *)p) {

    return false;

  }

  if (!data_blob_realloc(mem_ctx, blob, new_len)) {

    return false;

  }

  memcpy(blob->data + old_len, p, length);

  return true;

}

/**

  pad the length of a data blob to a multiple of

  'pad'. 'pad' must be a power of two.

**/

_PUBLIC_ bool data_blob_pad(TALLOC_CTX *mem_ctx, DATA_BLOB *blob,

          size_t pad)

{

  size_t old_len = blob->length;

  size_t new_len = (old_len + pad - 1) & ~(pad - 1);

  if (new_len < old_len || (pad & (pad - 1)) != 0) {

    return false;

  }

  if (!data_blob_realloc(mem_ctx, blob, new_len)) {

    return false;

  }

  memset(blob->data + old_len, 0, new_len - old_len);

  return true;

}