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  * $Id: photoid.c,v 1.2 2004/05/27 21:58:18 noodles Exp $
   9  */
  10
  11 #include <assert.h>
  12 #include <inttypes.h>
  13 #include <stdbool.h>
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16
  17 #include "keyid.h"
  18 #include "keyindex.h"
  19 #include "keystructs.h"
  20 #include "log.h"
  21 #include "photoid.h"
  22
  23 /**
  24  *      getphoto - returns an OpenPGP packet containing a photo id.
  25  *      @key: The key to return the photo id from.
  26  *      @index: The index of the photo to return.
  27  *      @photo: The photo data.
  28  *      @length: The length of the photo data.
  29  *
  30  *      This function returns the photo data contained in a supplied key.
  31  *      index specifies which photo id should be returned. If there's no such
  32  *      photo id NULL is returned. The returned data pointer refers to the key
  33  *      data supplied rather than a copy of it.
  34  */
  35 int getphoto(struct openpgp_publickey *key, int index, unsigned char **photo,
  36                 size_t *length)
  37 {
  38         struct openpgp_signedpacket_list *curuid = NULL;
  39         int                               i = 0;
  40         int                               j = 0;
  41
  42         assert(key != NULL);
  43         assert(photo != NULL);
  44         assert(length != NULL);
  45
  46         *photo = NULL;
  47
  48         curuid = key->uids;
  49         i = 0;
  50         while (*photo == NULL && curuid != NULL && i <= index) {
  51                 if (curuid->packet->tag == 17) {
  52                         if (i == index) {
  53                                 j = 0;
  54                                 *length = curuid->packet->data[j++];
  55                                 if (*length < 192) {
  56                                         /* length is correct */
  57                                 } else if (*length < 255) {
  58                                         *length -= 192;
  59                                         *length <<= 8;
  60                                         *length += curuid->packet->data[j++];
  61                                         *length +=  192;
  62                                 } else {
  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                                         *length <<= 8;
  69                                         *length += curuid->packet->data[j++];
  70                                 }
  71                                 logthing(LOGTHING_DEBUG, "Got photo, size %d",
  72                                                 *length);
  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);
  84 }