Add ability to drop overly large packets

[onak.git] / cleankey.c

diff --git a/cleankey.c b/cleankey.c
index afe5a06a82b7cb2aacf53c18e4d06cfebc03f7e0..fe24c3b6a31a7502de8554ce12bf692b3d18dbb5 100644 (file)
--- a/cleankey.c
+++ b/cleankey.c
@@ -26,7 +26,7 @@
 #include "log.h"
 #include "mem.h"
 #include "merge.h"
-#include "onak-conf.h"
+#include "openpgp.h"
 #include "sigcheck.h"
 
 /**
@@ -179,28 +179,86 @@ int clean_key_sighashes(struct openpgp_publickey *key)
        return removed;
 }
 
+#define UAT_LIMIT      0xFFFF
+#define UID_LIMIT      1024
+#define PACKET_LIMIT   8383            /* Fits in 2 byte packet length */
+int clean_large_packets(struct openpgp_publickey *key)
+{
+       struct openpgp_signedpacket_list **curuid = NULL;
+       struct openpgp_signedpacket_list *tmp = NULL;
+       bool                              drop;
+       int                               dropped = 0;
+
+       log_assert(key != NULL);
+       curuid = &key->uids;
+       while (*curuid != NULL) {
+               drop = false;
+               switch ((*curuid)->packet->tag) {
+               case OPENPGP_PACKET_UID:
+                       if ((*curuid)->packet->length > UID_LIMIT)
+                               drop = true;
+                       break;
+               case OPENPGP_PACKET_UAT:
+                       if ((*curuid)->packet->length > UAT_LIMIT)
+                               drop = true;
+                       break;
+               default:
+                       if ((*curuid)->packet->length > PACKET_LIMIT)
+                               drop = true;
+                       break;
+               }
+
+               if (drop) {
+                       logthing(LOGTHING_INFO,
+                                       "Dropping large (%d) packet, type %d",
+                                       (*curuid)->packet->length,
+                                       (*curuid)->packet->tag);
+                       /* Remove the entire large signed packet list */
+                       tmp = *curuid;
+                       *curuid = (*curuid)->next;
+                       tmp->next = NULL;
+                       free_signedpacket_list(tmp);
+                       dropped++;
+               } else {
+                       curuid = &(*curuid)->next;
+               }
+       }
+
+       return dropped;
+}
+
 /**
  *     cleankeys - Apply all available cleaning options on a list of keys.
- *     @keys: The list of keys to clean.
+ *     @policies: The cleaning policies to apply.
  *
- *     Applies all the cleaning options we can (eg duplicate key ids) to a
- *     list of keys. Returns 0 if no changes were made, otherwise the number
- *     of keys cleaned.
+ *     Applies the requested cleaning policies to a list of keys. These are
+ *     specified from the ONAK_CLEAN_* set of flags, or ONAK_CLEAN_ALL to
+ *     apply all available cleaning options. Returns 0 if no changes were
+ *     made, otherwise the number of keys cleaned. Note that some options
+ *     may result in keys being removed entirely from the list.
  */
-int cleankeys(struct openpgp_publickey *keys)
+int cleankeys(struct openpgp_publickey **keys, uint64_t policies)
 {
-       int changed = 0, count;
+       struct openpgp_publickey *curkey;
+       int changed = 0, count = 0;
+
+       if (keys == NULL)
+               return 0;
 
-       while (keys != NULL) {
-               count = dedupuids(keys);
-               count += dedupsubkeys(keys);
-               if (config.check_sighash) {
-                       count += clean_key_sighashes(keys);
+       curkey = *keys;
+       while (curkey != NULL) {
+               if (policies & ONAK_CLEAN_LARGE_PACKETS) {
+                       count += clean_large_packets(curkey);
+               }
+               count += dedupuids(curkey);
+               count += dedupsubkeys(curkey);
+               if (policies & ONAK_CLEAN_CHECK_SIGHASH) {
+                       count += clean_key_sighashes(curkey);
                }
                if (count > 0) {
                        changed++;
                }
-               keys = keys->next;
+               curkey = curkey->next;
        }
 
        return changed;