]> the.earth.li Git - onak.git/blobdiff - decodekey.c
Add ability to drop overly large packets
[onak.git] / decodekey.c
index eb0a79d2cfd2277adcb5d18ad89df19ce0ac6f59..0ff0625929849713a2597bf36769f009badab90c 100644 (file)
@@ -1,15 +1,22 @@
 /*
  * decodekey.c - Routines to further decode an OpenPGP key.
  *
- * Jonathan McDowell <noodles@earth.li>
+ * Copyright 2002-2008 Jonathan McDowell <noodles@earth.li>
  *
- * Copyright 2002 Project Purple
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; version 2 of the License.
  *
- * $Id: decodekey.c,v 1.6 2004/05/27 03:24:01 noodles Exp $
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
 #include <assert.h>
-#include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include "keyid.h"
 #include "keystructs.h"
 #include "ll.h"
-#include "log.h"
+#include "openpgp.h"
 
 /*
  *     parse_subpackets - Parse the subpackets of a Type 4 signature.
  *     @data: The subpacket data.
- *      @keyid: A pointer to where we should return the keyid.
+ *     @len: The amount of data available to read.
+ *     @parselen: The amount of data that was actually parsed.
+ *     @keyid: A pointer to where we should return the keyid.
+ *     @creationtime: A pointer to where we should return the creation time.
  *
  *     This function parses the subkey data of a Type 4 signature and fills
  *     in the supplied variables. It also returns the length of the data
- *     processed.
+ *     processed. If the value of any piece of data is not desired a NULL
+ *     can be passed instead of a pointer to a storage area for that value.
  */
-int parse_subpackets(unsigned char *data, uint64_t *keyid)
+onak_status_t parse_subpackets(unsigned char *data, size_t len,
+               size_t *parselen, uint64_t *keyid, time_t *creation)
 {
        int offset = 0;
        int length = 0;
@@ -39,8 +51,20 @@ int parse_subpackets(unsigned char *data, uint64_t *keyid)
 
        assert(data != NULL);
 
+       /* Make sure we actually have the 2 byte length field */
+       if (len < 2) {
+               return ONAK_E_INVALID_PKT;
+       }
+
        length = (data[0] << 8) + data[1] + 2;
 
+       /* If the length is off the end of the data available, it's bogus */
+       if (len < length) {
+               return ONAK_E_INVALID_PKT;
+       }
+
+       *parselen = length;
+
        offset = 2;
        while (offset < length) {
                packetlen = data[offset++];
@@ -50,54 +74,84 @@ int parse_subpackets(unsigned char *data, uint64_t *keyid)
                } else if (packetlen == 255) {
                        packetlen = data[offset++];
                        packetlen <<= 8;
-                       packetlen = data[offset++];
+                       packetlen |= data[offset++];
                        packetlen <<= 8;
-                       packetlen = data[offset++];
+                       packetlen |= data[offset++];
                        packetlen <<= 8;
-                       packetlen = data[offset++];
+                       packetlen |= data[offset++];
+               }
+               /* Check the supplied length is within the remaining data */
+               if (packetlen == 0 || (packetlen + offset) > length) {
+                       return ONAK_E_INVALID_PKT;
                }
                switch (data[offset] & 0x7F) {
-               case 2:
+               case OPENPGP_SIGSUB_CREATION:
                        /*
-                        * Signature creation time. Might want to output this?
+                        * Signature creation time.
                         */
+                       if (creation != NULL) {
+                               *creation = data[offset + packetlen - 4];
+                               *creation <<= 8;
+                               *creation = data[offset + packetlen - 3];
+                               *creation <<= 8;
+                               *creation = data[offset + packetlen - 2];
+                               *creation <<= 8;
+                               *creation = data[offset + packetlen - 1];
+                       }
                        break;
-               case 3:
                        /*
                         * Signature expiration time. Might want to output this?
                         */
                        break;
-               case 16:
-                       *keyid = data[offset+packetlen - 8];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 7];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 6];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 5];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 4];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 3];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 2];
-                       *keyid <<= 8;
-                       *keyid += data[offset+packetlen - 1];
-                       break;
-               case 20:
-                       /*
-                        * Annotation data.
-                        */
-                       break;
-
-               case 23:
-                       /*
-                        * Key server preferences. Including no-modify.
-                        */
+               case OPENPGP_SIGSUB_ISSUER:
+                       if (keyid != NULL) {
+                               *keyid = data[offset+packetlen - 8];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 7];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 6];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 5];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 4];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 3];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 2];
+                               *keyid <<= 8;
+                               *keyid += data[offset+packetlen - 1];
+                       }
                        break;
-               case 25:
+               case OPENPGP_SIGSUB_EXPIRY:
+               case OPENPGP_SIGSUB_EXPORTABLE:
+               case OPENPGP_SIGSUB_TRUSTSIG:
+               case OPENPGP_SIGSUB_REGEX:
+               case OPENPGP_SIGSUB_REVOCABLE:
+               case OPENPGP_SIGSUB_CAPABILITIES:
+               case OPENPGP_SIGSUB_KEYEXPIRY:
+               case OPENPGP_SIGSUB_ARR:
+               case OPENPGP_SIGSUB_PREFSYM:
+               case OPENPGP_SIGSUB_REVOCATION_KEY:
+               case OPENPGP_SIGSUB_ISSUER_UID:
+               case OPENPGP_SIGSUB_URL:
+               case OPENPGP_SIGSUB_ISSUER_FINGER:
+               case OPENPGP_SIGSUB_NOTATION:
+               case OPENPGP_SIGSUB_PREFHASH:
+               case OPENPGP_SIGSUB_PREFCOMPRESS:
+               case OPENPGP_SIGSUB_KEYSERVER:
+               case OPENPGP_SIGSUB_PREFKEYSERVER:
+               case OPENPGP_SIGSUB_PRIMARYUID:
+               case OPENPGP_SIGSUB_POLICYURI:
+               case OPENPGP_SIGSUB_KEYFLAGS:
+               case OPENPGP_SIGSUB_SIGNER_UID:
+               case OPENPGP_SIGSUB_REVOKE_REASON:
+               case OPENPGP_SIGSUB_FEATURES:
+               case OPENPGP_SIGSUB_SIGNATURE_TARGET:
+               case OPENPGP_SIGSUB_EMBEDDED_SIG:
                        /*
-                        * Primary UID.
+                        * Various subpacket types we know about, but don't
+                        * currently handle. Some are candidates for being
+                        * supported if we add signature checking support.
                         */
                        break;
                default:
@@ -106,38 +160,82 @@ int parse_subpackets(unsigned char *data, uint64_t *keyid)
                         * 7 is set in which case we log a major error.
                         */
                        if (data[offset] & 0x80) {
-                               logthing(LOGTHING_CRITICAL,
-                               "Critical subpacket type not parsed: 0x%X",
-                                       data[offset]);
+                               return ONAK_E_UNSUPPORTED_FEATURE;
                        }
-                               
                }
                offset += packetlen;
        }
 
-       return length;
+       return ONAK_E_OK;
 }
 
 /**
- *     keysigs - Return the sigs on a given OpenPGP signature list.
- *     @curll: The current linked list. Can be NULL to create a new list.
- *     @sigs: The signature list we want the sigs on.
+ *     sig_info - Get info on a given OpenPGP signature packet
+ *     @packet: The signature packet
+ *     @keyid: A pointer for where to return the signature keyid
+ *     @creation: A pointer for where to return the signature creation time
  *
- *     Returns a linked list of stats_key elements containing the sigs on the
- *     supplied OpenPGP packet list.
+ *     Gets any info about a signature packet; parses the subpackets for a v4
+ *     key or pulls the data directly from v2/3. NULL can be passed for any
+ *     values which aren't cared about.
  */
-struct ll *keysigs(struct ll *curll,
-               struct openpgp_packet_list *sigs)
+onak_status_t sig_info(struct openpgp_packet *packet, uint64_t *keyid,
+               time_t *creation)
 {
-       uint64_t keyid = 0;
-       
-       while (sigs != NULL) {
-               keyid = sig_keyid(sigs->packet);
-               sigs = sigs->next;
-               curll = lladd(curll, createandaddtohash(keyid));
+       size_t length = 0;
+       onak_status_t res;
+
+       if (packet != NULL) {
+               switch (packet->data[0]) {
+               case 2:
+               case 3:
+                       if (keyid != NULL) {
+                               *keyid = packet->data[7];
+                               *keyid <<= 8;
+                               *keyid += packet->data[8];
+                               *keyid <<= 8;
+                               *keyid += packet->data[9];
+                               *keyid <<= 8;
+                               *keyid += packet->data[10];
+                               *keyid <<= 8;
+                               *keyid += packet->data[11];
+                               *keyid <<= 8;
+                               *keyid += packet->data[12];
+                               *keyid <<= 8;
+                               *keyid += packet->data[13];
+                               *keyid <<= 8;
+                               *keyid += packet->data[14];
+                       }
+                       if (creation != NULL) {
+                               *creation = packet->data[3];
+                               *creation <<= 8;
+                               *creation = packet->data[4];
+                               *creation <<= 8;
+                               *creation = packet->data[5];
+                               *creation <<= 8;
+                               *creation = packet->data[6];
+                       }
+                       break;
+               case 4:
+                       res = parse_subpackets(&packet->data[4],
+                                       packet->length - 4,
+                                       &length, keyid, creation);
+                       if (res != ONAK_E_OK) {
+                               return res;
+                       }
+                       res = parse_subpackets(&packet->data[length + 4],
+                                       packet->length - (4 + length),
+                                       &length, keyid, creation);
+                       if (res != ONAK_E_OK) {
+                               return res;
+                       }
+                       break;
+               default:
+                       break;
+               }
        }
 
-       return curll;
+       return ONAK_E_OK;
 }
 
 /**
@@ -148,47 +246,14 @@ struct ll *keysigs(struct ll *curll,
  */
 uint64_t sig_keyid(struct openpgp_packet *packet)
 {
-       int length = 0;
        uint64_t keyid = 0;
-       
-       if (packet != NULL) {
-               keyid = 0;
-               switch (packet->data[0]) {
-               case 2:
-               case 3:
-                       keyid = packet->data[7];
-                       keyid <<= 8;
-                       keyid += packet->data[8];
-                       keyid <<= 8;
-                       keyid += packet->data[9];
-                       keyid <<= 8;
-                       keyid += packet->data[10];
-                       keyid <<= 8;
-                       keyid += packet->data[11];
-                       keyid <<= 8;
-                       keyid += packet->data[12];
-                       keyid <<= 8;
-                       keyid += packet->data[13];
-                       keyid <<= 8;
-                       keyid += packet->data[14];
-                       break;
-               case 4:
-                       length = parse_subpackets(&packet->data[4],
-                                       &keyid);
-                       parse_subpackets(&packet->data[length + 4],
-                                       &keyid);
-                       /*
-                        * Don't bother to look at the unsigned packets.
-                        */
-                       break;
-               default:
-                       break;
-               }
-       }
+
+       sig_info(packet, &keyid, NULL);
 
        return keyid;
 }
 
+
 /*
  * TODO: Abstract out; all our linked lists should be generic and then we can
  * llsize them.
@@ -229,7 +294,7 @@ char **keyuids(struct openpgp_publickey *key, char **primary)
                curuid = key->uids;
                while (curuid != NULL) {
                        buf[0] = 0;
-                       if (curuid->packet->tag == 13) {
+                       if (curuid->packet->tag == OPENPGP_PACKET_UID) {
                                snprintf(buf, 1023, "%.*s",
                                                (int) curuid->packet->length,
                                                curuid->packet->data);
@@ -257,21 +322,21 @@ char **keyuids(struct openpgp_publickey *key, char **primary)
  *     keysubkeys takes a public key structure and returns an array of the
  *     subkey keyids for that key.
  */
-uint64_t *keysubkeys(struct openpgp_publickey *key)
+struct openpgp_fingerprint *keysubkeys(struct openpgp_publickey *key)
 {
        struct openpgp_signedpacket_list *cursubkey = NULL;
-       uint64_t                         *subkeys = NULL;
+       struct openpgp_fingerprint       *subkeys = NULL;
        int                               count = 0;
-        
+
        if (key != NULL && key->subkeys != NULL) {
                subkeys = malloc((spsize(key->subkeys) + 1) *
-                               sizeof (uint64_t));
+                               sizeof (struct openpgp_fingerprint));
                cursubkey = key->subkeys;
                while (cursubkey != NULL) {
-                       subkeys[count++] = get_packetid(cursubkey->packet);
+                       get_fingerprint(cursubkey->packet, &subkeys[count++]);
                        cursubkey = cursubkey -> next;
                }
-               subkeys[count] = 0;
+               subkeys[count].length = 0;
        }
 
        return subkeys;