photoid.c

   1 /*
   2  * photoid.c - Routines for OpenPGP id photos.
   3  *
   4  * Jonathan McDowell <noodles@earth.li>
   5  *
   6  * Copyright 2004 Project Purple
   7  */
   8
   9 #include <assert.h>
  10 #include <inttypes.h>
  11 #include <stdbool.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14
  15 #include "keyid.h"
  16 #include "keyindex.h"
  17 #include "keystructs.h"
  18 #include "log.h"
  19 #include "photoid.h"
  20
  21 /**
  22  *      getphoto - returns an OpenPGP packet containing a photo id.
  23  *      @key: The key to return the photo id from.
  24  *      @index: The index of the photo to return.
  25  *      @photo: The photo data.
  26  *      @length: The length of the photo data.
  27  *
  28  *      This function returns the photo data contained in a supplied key.
  29  *      index specifies which photo id should be returned. If there's no such
  30  *      photo id NULL is returned. The returned data pointer refers to the key
  31  *      data supplied rather than a copy of it.
  32  */
  33 int getphoto(struct openpgp_publickey *key, int index, unsigned char **photo,
  34                 size_t *length)
  35 {
  36         struct openpgp_signedpacket_list *curuid = NULL;
  37         int                               i = 0;
  38         int                               j = 0;
  39
  40         assert(key != NULL);
  41         assert(photo != NULL);
  42         assert(length != NULL);
  43
  44         *photo = NULL;
  45
  46         curuid = key->uids;
  47         i = 0;
  48         while (*photo == NULL && curuid != NULL && i <= index) {
  49                 if (curuid->packet->tag == 17) {
  50                         if (i == index) {
  51                                 j = 0;
  52                                 *length = curuid->packet->data[j++];
  53                                 if (*length < 192) {
  54                                         /* length is correct */
  55                                 } else if (*length < 255) {
  56                                         *length -= 192;
  57                                         *length <<= 8;
  58                                         *length += curuid->packet->data[j++];
  59                                         *length +=  192;
  60                                 } else {
  61                                         *length = curuid->packet->data[j++];
  62                                         *length <<= 8;
  63                                         *length += curuid->packet->data[j++];
  64                                         *length <<= 8;
  65                                         *length += curuid->packet->data[j++];
  66                                         *length <<= 8;
  67                                         *length += curuid->packet->data[j++];
  68                                 }
  69                                 logthing(LOGTHING_DEBUG, "Got photo, size %d",
  70                                                 *length);
  71                                 j++;
  72                                 *length -= 17;
  73                                 *photo = &(curuid->packet->data[j+16]);
  74                         } else {
  75                                 i++;
  76                         }
  77                 }
  78                 curuid = curuid->next;
  79         }
  80
  81         return (*photo != NULL);
  82 }