gpg: Lookup key for merging/inserting only beu primary key.

* g10/getkey.c (get_keyblock_byfpr_fast): Add arg primary_only and
implement.
* g10/import.c (import_one_real): Simplify filling the fpr buffer with
zeroes.
(import_one_real): Find key only by primary fingerprint.
--

This should have been done early: When looking up the original
keyblock we want to update, we need to lookup it up only using the
primary key.  This avoids to find a key which has the primary key also
has a subkey.

GnuPG-bug-id: 7527

g10/getkey.c

@@ -1945,7 +1945,7 @@ get_pubkey_byfpr_fast (ctrl_t ctrl, PKT_public_key * pk,
   gpg_error_t err;
   KBNODE keyblock;
 
-  err = get_keyblock_byfpr_fast (ctrl, &keyblock, NULL, fpr, fprlen, 0);
+  err = get_keyblock_byfpr_fast (ctrl, &keyblock, NULL, 0, fpr, fprlen, 0);
   if (!err)
     {
       if (pk)
@@ -1962,11 +1962,14 @@ get_pubkey_byfpr_fast (ctrl_t ctrl, PKT_public_key * pk,
  * R_HD may be NULL.  If LOCK is set the handle has been opend in
  * locked mode and keydb_disable_caching () has been called.  On error
  * R_KEYBLOCK is set to NULL but R_HD must be released by the caller;
- * it may have a value of NULL, though.  This allows one to do an insert
+ * it may have a value of NULL, though.  This allows one to do an
- * operation on a locked keydb handle.  */
+ * insert operation on a locked keydb handle.  If PRIMARY_ONLY is set
+ * the function returns a keyblock which has the requested fingerprint
+ * has primary key.  */
 gpg_error_t
 get_keyblock_byfpr_fast (ctrl_t ctrl,
                          kbnode_t *r_keyblock, KEYDB_HANDLE *r_hd,
+                         int primary_only,
                          const byte *fpr, size_t fprlen, int lock)
 {
   gpg_error_t err;
@@ -1974,6 +1977,8 @@ get_keyblock_byfpr_fast (ctrl_t ctrl,
   kbnode_t keyblock;
   byte fprbuf[MAX_FINGERPRINT_LEN];
   int i;
+  byte tmpfpr[MAX_FINGERPRINT_LEN];
+  size_t tmpfprlen;
 
   if (r_keyblock)
     *r_keyblock = NULL;
@@ -2005,6 +2010,7 @@ get_keyblock_byfpr_fast (ctrl_t ctrl,
   if (r_hd)
     *r_hd = hd;
 
+ again:
   err = keydb_search_fpr (hd, fprbuf, fprlen);
   if (gpg_err_code (err) == GPG_ERR_NOT_FOUND)
     {
@@ -2024,6 +2030,17 @@ get_keyblock_byfpr_fast (ctrl_t ctrl,
   log_assert (keyblock->pkt->pkttype == PKT_PUBLIC_KEY
               || keyblock->pkt->pkttype == PKT_PUBLIC_SUBKEY);
 
+  if (primary_only)
+    {
+      fingerprint_from_pk (keyblock->pkt->pkt.public_key, tmpfpr, &tmpfprlen);
+      if (fprlen != tmpfprlen || memcmp (fpr, tmpfpr, fprlen))
+        {
+          release_kbnode (keyblock);
+          keyblock = NULL;
+          goto again;
+        }
+    }
+
   /* Not caching key here since it won't have all of the fields
      properly set. */
 

g10/import.c

@@ -1994,7 +1994,6 @@ import_one_real (ctrl_t ctrl,
   int mod_key = 0;
   int same_key = 0;
   int non_self_or_utk = 0;
-  size_t an;
   char pkstrbuf[PUBKEY_STRING_SIZE];
   int merge_keys_done = 0;
   int any_filter = 0;
@@ -2015,8 +2014,8 @@ import_one_real (ctrl_t ctrl,
   pk = node->pkt->pkt.public_key;
 
   fingerprint_from_pk (pk, fpr2, &fpr2len);
-  for (an = fpr2len; an < MAX_FINGERPRINT_LEN; an++)
+  if (MAX_FINGERPRINT_LEN > fpr2len)
-    fpr2[an] = 0;
+    memset (fpr2+fpr2len, 0, MAX_FINGERPRINT_LEN - fpr2len);
   keyid_from_pk( pk, keyid );
   uidnode = find_next_kbnode( keyblock, PKT_USER_ID );
 
@@ -2215,6 +2214,7 @@ import_one_real (ctrl_t ctrl,
 
   /* Do we have this key already in one of our pubrings ? */
   err = get_keyblock_byfpr_fast (ctrl, &keyblock_orig, &hd,
+                                 1 /*primary only */,
                                  fpr2, fpr2len, 1/*locked*/);
   if ((err
        && gpg_err_code (err) != GPG_ERR_NO_PUBKEY

g10/keydb.h

@@ -422,6 +422,7 @@ gpg_error_t get_pubkey_byfpr_fast (ctrl_t ctrl, PKT_public_key *pk,
 gpg_error_t get_keyblock_byfpr_fast (ctrl_t ctrl,
                                      kbnode_t *r_keyblock,
                                      KEYDB_HANDLE *r_hd,
+                                     int primary_only,
                                      const byte *fpr, size_t fprlen,
                                      int lock);