source4/lib/data_blob.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Easy management of byte-length data
   4    Copyright (C) Andrew Tridgell 2001
   5    Copyright (C) Andrew Bartlett 2001
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 /*******************************************************************
  25  construct a data blob, must be freed with data_blob_free()
  26  you can pass NULL for p and get a blank data blob
  27 *******************************************************************/
  28 DATA_BLOB data_blob_named(const void *p, size_t length, const char *name)
  29 {
  30         DATA_BLOB ret;
  31
  32         if (length == 0) {
  33                 ZERO_STRUCT(ret);
  34                 return ret;
  35         }
  36
  37         if (p) {
  38                 ret.data = talloc_memdup(NULL, p, length);
  39         } else {
  40                 ret.data = talloc(NULL, length);
  41         }
  42         if (ret.data == NULL) {
  43                 ret.length = 0;
  44                 return ret;
  45         }
  46         talloc_set_name_const(ret.data, name);
  47         ret.length = length;
  48         return ret;
  49 }
  50
  51 /*******************************************************************
  52  construct a data blob, using supplied TALLOC_CTX
  53 *******************************************************************/
  54 DATA_BLOB data_blob_talloc_named(TALLOC_CTX *mem_ctx, const void *p, size_t length, const char *name)
  55 {
  56         DATA_BLOB ret = data_blob_named(p, length, name);
  57
  58         if (ret.data) {
  59                 talloc_steal(mem_ctx, ret.data);
  60         }
  61         return ret;
  62 }
  63
  64
  65 /*******************************************************************
  66  reference a data blob, to the supplied TALLOC_CTX.
  67  Returns a NULL DATA_BLOB on failure
  68 *******************************************************************/
  69 DATA_BLOB data_blob_talloc_reference(TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
  70 {
  71         DATA_BLOB ret = *blob;
  72
  73         ret.data = talloc_reference(mem_ctx, blob->data);
  74
  75         if (!ret.data) {
  76                 return data_blob(NULL, 0);
  77         }
  78         return ret;
  79 }
  80
  81 /*******************************************************************
  82  construct a zero data blob, using supplied TALLOC_CTX.
  83  use this sparingly as it initialises data - better to initialise
  84  yourself if you want specific data in the blob
  85 *******************************************************************/
  86 DATA_BLOB data_blob_talloc_zero(TALLOC_CTX *mem_ctx, size_t length)
  87 {
  88         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, length);
  89         data_blob_clear(&blob);
  90         return blob;
  91 }
  92
  93 /*******************************************************************
  94 free a data blob
  95 *******************************************************************/
  96 void data_blob_free(DATA_BLOB *d)
  97 {
  98         if (d) {
  99                 talloc_free(d->data);
 100                 d->data = NULL;
 101                 d->length = 0;
 102         }
 103 }
 104
 105 /*******************************************************************
 106 clear a DATA_BLOB's contents
 107 *******************************************************************/
 108 void data_blob_clear(DATA_BLOB *d)
 109 {
 110         if (d->data) {
 111                 memset(d->data, 0, d->length);
 112         }
 113 }
 114
 115 /*******************************************************************
 116 free a data blob and clear its contents
 117 *******************************************************************/
 118 void data_blob_clear_free(DATA_BLOB *d)
 119 {
 120         data_blob_clear(d);
 121         data_blob_free(d);
 122 }
 123
 124
 125 /*******************************************************************
 126 check if two data blobs are equal
 127 *******************************************************************/
 128 BOOL data_blob_equal(const DATA_BLOB *d1, const DATA_BLOB *d2)
 129 {
 130         if (d1->length != d2->length) {
 131                 return False;
 132         }
 133         if (d1->data == d2->data) {
 134                 return True;
 135         }
 136         if (d1->data == NULL || d2->data == NULL) {
 137                 return False;
 138         }
 139         if (memcmp(d1->data, d2->data, d1->length) == 0) {
 140                 return True;
 141         }
 142         return False;
 143 }
 144
 145 /*******************************************************************
 146 print the data_blob as hex string
 147 *******************************************************************/
 148 char *data_blob_hex_string(TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
 149 {
 150         int i;
 151         char *hex_string;
 152
 153         hex_string = talloc_array_p(mem_ctx, char, (blob->length*2)+1);
 154         if (!hex_string) {
 155                 return NULL;
 156         }
 157
 158         for (i = 0; i < blob->length; i++)
 159                 slprintf(&hex_string[i*2], 3, "%02X", blob->data[i]);
 160
 161         return hex_string;
 162 }
 163
 164 /*
 165   useful for constructing data blobs in test suites, while
 166   avoiding const warnings
 167 */
 168 DATA_BLOB data_blob_string_const(const char *str)
 169 {
 170         DATA_BLOB blob;
 171         blob.data = discard_const(str);
 172         blob.length = strlen(str);
 173         return blob;
 174 }
 175
 176 DATA_BLOB data_blob_const(const void *p, size_t length)
 177 {
 178         DATA_BLOB blob;
 179         blob.data = discard_const(p);
 180         blob.length = length;
 181         return blob;
 182 }