decodekey.c

   1 /*
   2  * decodekey.c - Routines to further decode an OpenPGP key.
   3  *
   4  * Jonathan McDowell <noodles@earth.li>
   5  *
   6  * Copyright 2002 Project Purple
   7  */
   8
   9 #include <stdbool.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <time.h>
  14
  15 #include "decodekey.h"
  16 #include "hash.h"
  17 #include "keyid.h"
  18 #include "keystructs.h"
  19 #include "ll.h"
  20 #include "log.h"
  21
  22 /*
  23  *      parse_subpackets - Parse the subpackets of a Type 4 signature.
  24  *      @data: The subpacket data.
  25  *      @keyid: A pointer to where we should return the keyid.
  26  *
  27  *      This function parses the subkey data of a Type 4 signature and fills
  28  *      in the supplied variables. It also returns the length of the data
  29  *      processed.
  30  */
  31 int parse_subpackets(unsigned char *data, uint64_t *keyid)
  32 {
  33         int offset = 0;
  34         int length = 0;
  35         int packetlen = 0;
  36
  37         log_assert(data != NULL);
  38
  39         length = (data[0] << 8) + data[1] + 2;
  40
  41         offset = 2;
  42         while (offset < length) {
  43                 packetlen = data[offset++];
  44                 if (packetlen > 191 && packetlen < 255) {
  45                         packetlen = ((packetlen - 192) << 8) +
  46                                         data[offset++] + 192;
  47                 } else if (packetlen == 255) {
  48                         packetlen = data[offset++];
  49                         packetlen <<= 8;
  50                         packetlen = data[offset++];
  51                         packetlen <<= 8;
  52                         packetlen = data[offset++];
  53                         packetlen <<= 8;
  54                         packetlen = data[offset++];
  55                 }
  56                 switch (data[offset] & 0x7F) {
  57                 case 2:
  58                         /*
  59                          * Signature creation time. Might want to output this?
  60                          */
  61                         break;
  62                 case 3:
  63                         /*
  64                          * Signature expiration time. Might want to output this?
  65                          */
  66                         break;
  67                 case 16:
  68                         *keyid = data[offset+packetlen - 8];
  69                         *keyid <<= 8;
  70                         *keyid += data[offset+packetlen - 7];
  71                         *keyid <<= 8;
  72                         *keyid += data[offset+packetlen - 6];
  73                         *keyid <<= 8;
  74                         *keyid += data[offset+packetlen - 5];
  75                         *keyid <<= 8;
  76                         *keyid += data[offset+packetlen - 4];
  77                         *keyid <<= 8;
  78                         *keyid += data[offset+packetlen - 3];
  79                         *keyid <<= 8;
  80                         *keyid += data[offset+packetlen - 2];
  81                         *keyid <<= 8;
  82                         *keyid += data[offset+packetlen - 1];
  83                         break;
  84                 case 20:
  85                         /*
  86                          * Annotation data.
  87                          */
  88                         break;
  89
  90                 case 23:
  91                         /*
  92                          * Key server preferences. Including no-modify.
  93                          */
  94                         break;
  95                 case 25:
  96                         /*
  97                          * Primary UID.
  98                          */
  99                         break;
 100                 default:
 101                         /*
 102                          * We don't care about unrecognized packets unless bit
 103                          * 7 is set in which case we log a major error.
 104                          */
 105                         if (data[offset] & 0x80) {
 106                                 logthing(LOGTHING_CRITICAL,
 107                                 "Critical subpacket type not parsed: 0x%X",
 108                                         data[offset]);
 109                         }
 110
 111                 }
 112                 offset += packetlen;
 113         }
 114
 115         return length;
 116 }
 117
 118 /**
 119  *      keysigs - Return the sigs on a given OpenPGP signature list.
 120  *      @curll: The current linked list. Can be NULL to create a new list.
 121  *      @sigs: The signature list we want the sigs on.
 122  *
 123  *      Returns a linked list of stats_key elements containing the sigs on the
 124  *      supplied OpenPGP packet list.
 125  */
 126 struct ll *keysigs(struct ll *curll,
 127                 struct openpgp_packet_list *sigs)
 128 {
 129         uint64_t keyid = 0;
 130
 131         while (sigs != NULL) {
 132                 keyid = sig_keyid(sigs->packet);
 133                 sigs = sigs->next;
 134                 curll = lladd(curll, createandaddtohash(keyid));
 135         }
 136
 137         return curll;
 138 }
 139
 140 /**
 141  *      sig_keyid - Return the keyid for a given OpenPGP signature packet.
 142  *      @packet: The signature packet.
 143  *
 144  *      Returns the keyid for the supplied signature packet.
 145  */
 146 uint64_t sig_keyid(struct openpgp_packet *packet)
 147 {
 148         int length = 0;
 149         uint64_t keyid = 0;
 150
 151         if (packet != NULL) {
 152                 keyid = 0;
 153                 switch (packet->data[0]) {
 154                 case 2:
 155                 case 3:
 156                         keyid = packet->data[7];
 157                         keyid <<= 8;
 158                         keyid += packet->data[8];
 159                         keyid <<= 8;
 160                         keyid += packet->data[9];
 161                         keyid <<= 8;
 162                         keyid += packet->data[10];
 163                         keyid <<= 8;
 164                         keyid += packet->data[11];
 165                         keyid <<= 8;
 166                         keyid += packet->data[12];
 167                         keyid <<= 8;
 168                         keyid += packet->data[13];
 169                         keyid <<= 8;
 170                         keyid += packet->data[14];
 171                         break;
 172                 case 4:
 173                         length = parse_subpackets(&packet->data[4],
 174                                         &keyid);
 175                         parse_subpackets(&packet->data[length + 4],
 176                                         &keyid);
 177                         /*
 178                          * Don't bother to look at the unsigned packets.
 179                          */
 180                         break;
 181                 default:
 182                         break;
 183                 }
 184         }
 185
 186         return keyid;
 187 }
 188
 189 /*
 190  * TODO: Abstract out; all our linked lists should be generic and then we can
 191  * llsize them.
 192  */
 193 int spsize(struct openpgp_signedpacket_list *list)
 194 {
 195         int size = 0;
 196         struct openpgp_signedpacket_list *cur;
 197
 198         for (cur = list; cur != NULL; cur = cur->next, size++) ;
 199
 200         return size;
 201 }
 202
 203 /**
 204  *      keyuids - Takes a key and returns an array of its UIDs
 205  *      @key: The key to get the uids of.
 206  *      @primary: A pointer to store the primary UID in.
 207  *
 208  *      keyuids takes a public key structure and builds an array of the UIDs
 209  *      on the key. It also attempts to work out the primary UID and returns a
 210  *      separate pointer to that particular element of the array.
 211  */
 212 char **keyuids(struct openpgp_publickey *key, char **primary)
 213 {
 214         struct openpgp_signedpacket_list *curuid = NULL;
 215         char buf[1024];
 216         char **uids = NULL;
 217         int count = 0;
 218
 219         if (primary != NULL) {
 220                 *primary = NULL;
 221         }
 222
 223         if (key != NULL && key->uids != NULL) {
 224                 uids = malloc((spsize(key->uids) + 1) * sizeof (char *));
 225
 226                 curuid = key->uids;
 227                 while (curuid != NULL) {
 228                         buf[0] = 0;
 229                         if (curuid->packet->tag == 13) {
 230                                 snprintf(buf, 1023, "%.*s",
 231                                                 (int) curuid->packet->length,
 232                                                 curuid->packet->data);
 233                                 uids[count++] = strdup(buf);
 234                         }
 235                         curuid = curuid -> next;
 236                 }
 237                 uids[count] = NULL;
 238
 239                 /*
 240                  * TODO: Parse subpackets for real primary ID (v4 keys)
 241                  */
 242                 if (primary != NULL) {
 243                         *primary = uids[0];
 244                 }
 245         }
 246
 247         return uids;
 248 }
 249
 250 /**
 251  *      keysubkeys - Takes a key and returns an array of its subkey keyids.
 252  *      @key: The key to get the subkeys of.
 253  *
 254  *      keysubkeys takes a public key structure and returns an array of the
 255  *      subkey keyids for that key.
 256  */
 257 uint64_t *keysubkeys(struct openpgp_publickey *key)
 258 {
 259         struct openpgp_signedpacket_list *cursubkey = NULL;
 260         uint64_t                         *subkeys = NULL;
 261         int                               count = 0;
 262
 263         if (key != NULL && key->subkeys != NULL) {
 264                 subkeys = malloc((spsize(key->subkeys) + 1) *
 265                                 sizeof (uint64_t));
 266                 cursubkey = key->subkeys;
 267                 while (cursubkey != NULL) {
 268                         subkeys[count++] = get_packetid(cursubkey->packet);
 269                         cursubkey = cursubkey -> next;
 270                 }
 271                 subkeys[count] = 0;
 272         }
 273
 274         return subkeys;
 275 }