decodekey.c

   1 /*
   2  * decodekey.c - Routines to further decode an OpenPGP key.
   3  *
   4  * Copyright 2002-2008 Jonathan McDowell <noodles@earth.li>
   5  */
   6
   7 #include <stdbool.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <time.h>
  12
  13 #include "decodekey.h"
  14 #include "hash.h"
  15 #include "keyid.h"
  16 #include "keystructs.h"
  17 #include "ll.h"
  18 #include "log.h"
  19
  20 /*
  21  *      parse_subpackets - Parse the subpackets of a Type 4 signature.
  22  *      @data: The subpacket data.
  23  *      @keyid: A pointer to where we should return the keyid.
  24  *      @creationtime: A pointer to where we should return the creation time.
  25  *
  26  *      This function parses the subkey data of a Type 4 signature and fills
  27  *      in the supplied variables. It also returns the length of the data
  28  *      processed. If the value of any piece of data is not desired a NULL
  29  *      can be passed instead of a pointer to a storage area for that value.
  30  */
  31 int parse_subpackets(unsigned char *data, uint64_t *keyid, time_t *creation)
  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.
  60                          */
  61                         if (creation != NULL) {
  62                                 *creation = data[offset + packetlen - 4];
  63                                 *creation <<= 8;
  64                                 *creation = data[offset + packetlen - 3];
  65                                 *creation <<= 8;
  66                                 *creation = data[offset + packetlen - 2];
  67                                 *creation <<= 8;
  68                                 *creation = data[offset + packetlen - 1];
  69                         }
  70                         break;
  71                 case 3:
  72                         /*
  73                          * Signature expiration time. Might want to output this?
  74                          */
  75                         break;
  76                 case 6:
  77                         /*
  78                          * Regular expression for UIDs this sig is over.
  79                          */
  80                         break;
  81                 case 16:
  82                         if (keyid != NULL) {
  83                                 *keyid = data[offset+packetlen - 8];
  84                                 *keyid <<= 8;
  85                                 *keyid += data[offset+packetlen - 7];
  86                                 *keyid <<= 8;
  87                                 *keyid += data[offset+packetlen - 6];
  88                                 *keyid <<= 8;
  89                                 *keyid += data[offset+packetlen - 5];
  90                                 *keyid <<= 8;
  91                                 *keyid += data[offset+packetlen - 4];
  92                                 *keyid <<= 8;
  93                                 *keyid += data[offset+packetlen - 3];
  94                                 *keyid <<= 8;
  95                                 *keyid += data[offset+packetlen - 2];
  96                                 *keyid <<= 8;
  97                                 *keyid += data[offset+packetlen - 1];
  98                         }
  99                         break;
 100                 case 20:
 101                         /*
 102                          * Annotation data.
 103                          */
 104                         break;
 105
 106                 case 23:
 107                         /*
 108                          * Key server preferences. Including no-modify.
 109                          */
 110                         break;
 111                 case 25:
 112                         /*
 113                          * Primary UID.
 114                          */
 115                         break;
 116                 case 26:
 117                         /*
 118                          * Policy URI.
 119                          */
 120                         break;
 121                 default:
 122                         /*
 123                          * We don't care about unrecognized packets unless bit
 124                          * 7 is set in which case we log a major error.
 125                          */
 126                         if (data[offset] & 0x80) {
 127                                 logthing(LOGTHING_CRITICAL,
 128                                 "Critical subpacket type not parsed: 0x%X",
 129                                         data[offset]);
 130                         }
 131
 132                 }
 133                 offset += packetlen;
 134         }
 135
 136         return length;
 137 }
 138
 139 /**
 140  *      keysigs - Return the sigs on a given OpenPGP signature list.
 141  *      @curll: The current linked list. Can be NULL to create a new list.
 142  *      @sigs: The signature list we want the sigs on.
 143  *
 144  *      Returns a linked list of stats_key elements containing the sigs on the
 145  *      supplied OpenPGP packet list.
 146  */
 147 struct ll *keysigs(struct ll *curll,
 148                 struct openpgp_packet_list *sigs)
 149 {
 150         uint64_t keyid = 0;
 151
 152         while (sigs != NULL) {
 153                 keyid = sig_keyid(sigs->packet);
 154                 sigs = sigs->next;
 155                 curll = lladd(curll, createandaddtohash(keyid));
 156         }
 157
 158         return curll;
 159 }
 160
 161 /**
 162  *      sig_info - Get info on a given OpenPGP signature packet
 163  *      @packet: The signature packet
 164  *      @keyid: A pointer for where to return the signature keyid
 165  *      @creation: A pointer for where to return the signature creation time
 166  *
 167  *      Gets any info about a signature packet; parses the subpackets for a v4
 168  *      key or pulls the data directly from v2/3. NULL can be passed for any
 169  *      values which aren't cared about.
 170  */
 171 void sig_info(struct openpgp_packet *packet, uint64_t *keyid, time_t *creation)
 172 {
 173         int length = 0;
 174
 175         if (packet != NULL) {
 176                 switch (packet->data[0]) {
 177                 case 2:
 178                 case 3:
 179                         if (keyid != NULL) {
 180                                 *keyid = packet->data[7];
 181                                 *keyid <<= 8;
 182                                 *keyid += packet->data[8];
 183                                 *keyid <<= 8;
 184                                 *keyid += packet->data[9];
 185                                 *keyid <<= 8;
 186                                 *keyid += packet->data[10];
 187                                 *keyid <<= 8;
 188                                 *keyid += packet->data[11];
 189                                 *keyid <<= 8;
 190                                 *keyid += packet->data[12];
 191                                 *keyid <<= 8;
 192                                 *keyid += packet->data[13];
 193                                 *keyid <<= 8;
 194                                 *keyid += packet->data[14];
 195                         }
 196                         if (creation != NULL) {
 197                                 *creation = packet->data[3];
 198                                 *creation <<= 8;
 199                                 *creation = packet->data[4];
 200                                 *creation <<= 8;
 201                                 *creation = packet->data[5];
 202                                 *creation <<= 8;
 203                                 *creation = packet->data[6];
 204                         }
 205                         break;
 206                 case 4:
 207                         length = parse_subpackets(&packet->data[4],
 208                                         keyid, creation);
 209                         parse_subpackets(&packet->data[length + 4],
 210                                         keyid, creation);
 211                         /*
 212                          * Don't bother to look at the unsigned packets.
 213                          */
 214                         break;
 215                 default:
 216                         break;
 217                 }
 218         }
 219
 220         return;
 221 }
 222
 223 /**
 224  *      sig_keyid - Return the keyid for a given OpenPGP signature packet.
 225  *      @packet: The signature packet.
 226  *
 227  *      Returns the keyid for the supplied signature packet.
 228  */
 229 uint64_t sig_keyid(struct openpgp_packet *packet)
 230 {
 231         uint64_t keyid = 0;
 232
 233         sig_info(packet, &keyid, NULL);
 234
 235         return keyid;
 236 }
 237
 238
 239 /*
 240  * TODO: Abstract out; all our linked lists should be generic and then we can
 241  * llsize them.
 242  */
 243 int spsize(struct openpgp_signedpacket_list *list)
 244 {
 245         int size = 0;
 246         struct openpgp_signedpacket_list *cur;
 247
 248         for (cur = list; cur != NULL; cur = cur->next, size++) ;
 249
 250         return size;
 251 }
 252
 253 /**
 254  *      keyuids - Takes a key and returns an array of its UIDs
 255  *      @key: The key to get the uids of.
 256  *      @primary: A pointer to store the primary UID in.
 257  *
 258  *      keyuids takes a public key structure and builds an array of the UIDs
 259  *      on the key. It also attempts to work out the primary UID and returns a
 260  *      separate pointer to that particular element of the array.
 261  */
 262 char **keyuids(struct openpgp_publickey *key, char **primary)
 263 {
 264         struct openpgp_signedpacket_list *curuid = NULL;
 265         char buf[1024];
 266         char **uids = NULL;
 267         int count = 0;
 268
 269         if (primary != NULL) {
 270                 *primary = NULL;
 271         }
 272
 273         if (key != NULL && key->uids != NULL) {
 274                 uids = malloc((spsize(key->uids) + 1) * sizeof (char *));
 275
 276                 curuid = key->uids;
 277                 while (curuid != NULL) {
 278                         buf[0] = 0;
 279                         if (curuid->packet->tag == 13) {
 280                                 snprintf(buf, 1023, "%.*s",
 281                                                 (int) curuid->packet->length,
 282                                                 curuid->packet->data);
 283                                 uids[count++] = strdup(buf);
 284                         }
 285                         curuid = curuid -> next;
 286                 }
 287                 uids[count] = NULL;
 288
 289                 /*
 290                  * TODO: Parse subpackets for real primary ID (v4 keys)
 291                  */
 292                 if (primary != NULL) {
 293                         *primary = uids[0];
 294                 }
 295         }
 296
 297         return uids;
 298 }
 299
 300 /**
 301  *      keysubkeys - Takes a key and returns an array of its subkey keyids.
 302  *      @key: The key to get the subkeys of.
 303  *
 304  *      keysubkeys takes a public key structure and returns an array of the
 305  *      subkey keyids for that key.
 306  */
 307 uint64_t *keysubkeys(struct openpgp_publickey *key)
 308 {
 309         struct openpgp_signedpacket_list *cursubkey = NULL;
 310         uint64_t                         *subkeys = NULL;
 311         int                               count = 0;
 312
 313         if (key != NULL && key->subkeys != NULL) {
 314                 subkeys = malloc((spsize(key->subkeys) + 1) *
 315                                 sizeof (uint64_t));
 316                 cursubkey = key->subkeys;
 317                 while (cursubkey != NULL) {
 318                         subkeys[count++] = get_packetid(cursubkey->packet);
 319                         cursubkey = cursubkey -> next;
 320                 }
 321                 subkeys[count] = 0;
 322         }
 323
 324         return subkeys;
 325 }