photoid.c

   1 /*
   2  * photoid.c - Routines for OpenPGP id photos.
   3  *
   4  * Copyright 2004 Jonathan McDowell <noodles@earth.li>
   5  *
   6  * This program is free software: you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  13  * more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along with
  16  * this program; if not, write to the Free Software Foundation, Inc., 51
  17  * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  */
  19
  20 #include <stdlib.h>
  21
  22 #include "keystructs.h"
  23 #include "onak.h"
  24 #include "photoid.h"
  25
  26 /**
  27  *      getphoto - returns an OpenPGP packet containing a photo id.
  28  *      @key: The key to return the photo id from.
  29  *      @index: The index of the photo to return.
  30  *      @photo: The photo data.
  31  *      @length: The length of the photo data.
  32  *
  33  *      This function returns the photo data contained in a supplied key.
  34  *      index specifies which photo id should be returned. If there's no such
  35  *      photo id NULL is returned. The returned data pointer refers to the key
  36  *      data supplied rather than a copy of it.
  37  */
  38 onak_status_t getphoto(struct openpgp_publickey *key, int index,
  39                 unsigned char **photo, size_t *length)
  40 {
  41         struct openpgp_signedpacket_list *curuid = NULL;
  42         int                               i = 0;
  43         int                               j = 0;
  44
  45         if (key == NULL || photo == NULL || length == NULL)
  46                 return ONAK_E_INVALID_PARAM;
  47
  48         *photo = NULL;
  49
  50         curuid = key->uids;
  51         i = 0;
  52         while (*photo == NULL && curuid != NULL && i <= index) {
  53                 if (curuid->packet->tag == 17) {
  54                         if (i == index) {
  55                                 j = 0;
  56                                 *length = curuid->packet->data[j++];
  57                                 if (*length < 192) {
  58                                         /* length is correct */
  59                                 } else if (*length < 255) {
  60                                         *length -= 192;
  61                                         *length <<= 8;
  62                                         *length += curuid->packet->data[j++];
  63                                         *length +=  192;
  64                                 } else {
  65                                         *length = curuid->packet->data[j++];
  66                                         *length <<= 8;
  67                                         *length += curuid->packet->data[j++];
  68                                         *length <<= 8;
  69                                         *length += curuid->packet->data[j++];
  70                                         *length <<= 8;
  71                                         *length += curuid->packet->data[j++];
  72                                 }
  73                                 j++;
  74                                 *length -= 17;
  75                                 *photo = &(curuid->packet->data[j+16]);
  76                         } else {
  77                                 i++;
  78                         }
  79                 }
  80                 curuid = curuid->next;
  81         }
  82
  83         return *photo == NULL ? ONAK_E_NOT_FOUND : ONAK_E_OK;
  84 }