lib/util/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 3 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, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22
  23 const DATA_BLOB data_blob_null = { NULL, 0 };
  24
  25 /**
  26  * @file
  27  * @brief Manipulation of arbitrary data blobs
  28  **/
  29
  30 /**
  31  construct a data blob, must be freed with data_blob_free()
  32  you can pass NULL for p and get a blank data blob
  33 **/
  34 _PUBLIC_ DATA_BLOB data_blob_named(const void *p, size_t length, const char *name)
  35 {
  36         return data_blob_talloc_named(NULL, p, length, name);
  37 }
  38
  39 /**
  40  construct a data blob, using supplied TALLOC_CTX
  41 **/
  42 _PUBLIC_ DATA_BLOB data_blob_talloc_named(TALLOC_CTX *mem_ctx, const void *p, size_t length, const char *name)
  43 {
  44         DATA_BLOB ret;
  45
  46         if (p == NULL && length == 0) {
  47                 ZERO_STRUCT(ret);
  48                 return ret;
  49         }
  50
  51         if (p) {
  52                 ret.data = (uint8_t *)talloc_memdup(mem_ctx, p, length);
  53         } else {
  54                 ret.data = talloc_array(mem_ctx, uint8_t, length);
  55         }
  56         if (ret.data == NULL) {
  57                 ret.length = 0;
  58                 return ret;
  59         }
  60         talloc_set_name_const(ret.data, name);
  61         ret.length = length;
  62         return ret;
  63 }
  64
  65 /**
  66  construct a zero data blob, using supplied TALLOC_CTX.
  67  use this sparingly as it initialises data - better to initialise
  68  yourself if you want specific data in the blob
  69 **/
  70 _PUBLIC_ DATA_BLOB data_blob_talloc_zero(TALLOC_CTX *mem_ctx, size_t length)
  71 {
  72         DATA_BLOB blob = data_blob_talloc(mem_ctx, NULL, length);
  73         data_blob_clear(&blob);
  74         return blob;
  75 }
  76
  77 /**
  78 free a data blob
  79 **/
  80 _PUBLIC_ void data_blob_free(DATA_BLOB *d)
  81 {
  82         if (d) {
  83                 talloc_free(d->data);
  84                 d->data = NULL;
  85                 d->length = 0;
  86         }
  87 }
  88
  89 /**
  90 clear a DATA_BLOB's contents
  91 **/
  92 _PUBLIC_ void data_blob_clear(DATA_BLOB *d)
  93 {
  94         if (d->data) {
  95                 memset(d->data, 0, d->length);
  96         }
  97 }
  98
  99 /**
 100 free a data blob and clear its contents
 101 **/
 102 _PUBLIC_ void data_blob_clear_free(DATA_BLOB *d)
 103 {
 104         data_blob_clear(d);
 105         data_blob_free(d);
 106 }
 107
 108
 109 /**
 110 check if two data blobs are equal
 111 **/
 112 _PUBLIC_ int data_blob_cmp(const DATA_BLOB *d1, const DATA_BLOB *d2)
 113 {
 114         int ret;
 115         if (d1->data == NULL && d2->data != NULL) {
 116                 return -1;
 117         }
 118         if (d1->data != NULL && d2->data == NULL) {
 119                 return 1;
 120         }
 121         if (d1->data == d2->data) {
 122                 return d1->length - d2->length;
 123         }
 124         ret = memcmp(d1->data, d2->data, MIN(d1->length, d2->length));
 125         if (ret == 0) {
 126                 return d1->length - d2->length;
 127         }
 128         return ret;
 129 }
 130
 131 /**
 132 print the data_blob as hex string
 133 **/
 134 _PUBLIC_ char *data_blob_hex_string_lower(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob)
 135 {
 136         int i;
 137         char *hex_string;
 138
 139         hex_string = talloc_array(mem_ctx, char, (blob->length*2)+1);
 140         if (!hex_string) {
 141                 return NULL;
 142         }
 143
 144         /* this must be lowercase or w2k8 cannot join a samba domain,
 145            as this routine is used to encode extended DNs and windows
 146            only accepts lowercase hexadecimal numbers */
 147         for (i = 0; i < blob->length; i++)
 148                 slprintf(&hex_string[i*2], 3, "%02x", blob->data[i]);
 149
 150         hex_string[(blob->length*2)] = '\0';
 151         return hex_string;
 152 }
 153
 154 _PUBLIC_ char *data_blob_hex_string_upper(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob)
 155 {
 156         int i;
 157         char *hex_string;
 158
 159         hex_string = talloc_array(mem_ctx, char, (blob->length*2)+1);
 160         if (!hex_string) {
 161                 return NULL;
 162         }
 163
 164         for (i = 0; i < blob->length; i++)
 165                 slprintf(&hex_string[i*2], 3, "%02X", blob->data[i]);
 166
 167         hex_string[(blob->length*2)] = '\0';
 168         return hex_string;
 169 }
 170
 171 /**
 172   useful for constructing data blobs in test suites, while
 173   avoiding const warnings
 174 **/
 175 _PUBLIC_ DATA_BLOB data_blob_string_const(const char *str)
 176 {
 177         DATA_BLOB blob;
 178         blob.data = discard_const_p(uint8_t, str);
 179         blob.length = str ? strlen(str) : 0;
 180         return blob;
 181 }
 182
 183 /**
 184   useful for constructing data blobs in test suites, while
 185   avoiding const warnings
 186 **/
 187 _PUBLIC_ DATA_BLOB data_blob_string_const_null(const char *str)
 188 {
 189         DATA_BLOB blob;
 190         blob.data = discard_const_p(uint8_t, str);
 191         blob.length = str ? strlen(str)+1 : 0;
 192         return blob;
 193 }
 194
 195 /**
 196  * Create a new data blob from const data
 197  */
 198
 199 _PUBLIC_ DATA_BLOB data_blob_const(const void *p, size_t length)
 200 {
 201         DATA_BLOB blob;
 202         blob.data = discard_const_p(uint8_t, p);
 203         blob.length = length;
 204         return blob;
 205 }
 206
 207
 208 /**
 209   realloc a data_blob
 210 **/
 211 _PUBLIC_ bool data_blob_realloc(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, size_t length)
 212 {
 213         blob->data = talloc_realloc(mem_ctx, blob->data, uint8_t, length);
 214         if (blob->data == NULL)
 215                 return false;
 216         blob->length = length;
 217         return true;
 218 }
 219
 220
 221 /**
 222   append some data to a data blob
 223 **/
 224 _PUBLIC_ bool data_blob_append(TALLOC_CTX *mem_ctx, DATA_BLOB *blob,
 225                                    const void *p, size_t length)
 226 {
 227         size_t old_len = blob->length;
 228         size_t new_len = old_len + length;
 229         if (new_len < length || new_len < old_len) {
 230                 return false;
 231         }
 232
 233         if ((const uint8_t *)p + length < (const uint8_t *)p) {
 234                 return false;
 235         }
 236
 237         if (!data_blob_realloc(mem_ctx, blob, new_len)) {
 238                 return false;
 239         }
 240
 241         memcpy(blob->data + old_len, p, length);
 242         return true;
 243 }
 244