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 <inttypes.h>
  21 #include <stdbool.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24
  25 #include "keyid.h"
  26 #include "keyindex.h"
  27 #include "keystructs.h"
  28 #include "log.h"
  29 #include "photoid.h"
  30
  31 /**
  32  *      getphoto - returns an OpenPGP packet containing a photo id.
  33  *      @key: The key to return the photo id from.
  34  *      @index: The index of the photo to return.
  35  *      @photo: The photo data.
  36  *      @length: The length of the photo data.
  37  *
  38  *      This function returns the photo data contained in a supplied key.
  39  *      index specifies which photo id should be returned. If there's no such
  40  *      photo id NULL is returned. The returned data pointer refers to the key
  41  *      data supplied rather than a copy of it.
  42  */
  43 int getphoto(struct openpgp_publickey *key, int index, unsigned char **photo,
  44                 size_t *length)
  45 {
  46         struct openpgp_signedpacket_list *curuid = NULL;
  47         int                               i = 0;
  48         int                               j = 0;
  49
  50         log_assert(key != NULL);
  51         log_assert(photo != NULL);
  52         log_assert(length != NULL);
  53
  54         *photo = NULL;
  55
  56         curuid = key->uids;
  57         i = 0;
  58         while (*photo == NULL && curuid != NULL && i <= index) {
  59                 if (curuid->packet->tag == 17) {
  60                         if (i == index) {
  61                                 j = 0;
  62                                 *length = curuid->packet->data[j++];
  63                                 if (*length < 192) {
  64                                         /* length is correct */
  65                                 } else if (*length < 255) {
  66                                         *length -= 192;
  67                                         *length <<= 8;
  68                                         *length += curuid->packet->data[j++];
  69                                         *length +=  192;
  70                                 } else {
  71                                         *length = curuid->packet->data[j++];
  72                                         *length <<= 8;
  73                                         *length += curuid->packet->data[j++];
  74                                         *length <<= 8;
  75                                         *length += curuid->packet->data[j++];
  76                                         *length <<= 8;
  77                                         *length += curuid->packet->data[j++];
  78                                 }
  79                                 logthing(LOGTHING_DEBUG, "Got photo, size %d",
  80                                                 *length);
  81                                 j++;
  82                                 *length -= 17;
  83                                 *photo = &(curuid->packet->data[j+16]);
  84                         } else {
  85                                 i++;
  86                         }
  87                 }
  88                 curuid = curuid->next;
  89         }
  90
  91         return (*photo != NULL);
  92 }