* keyserver-internal.h, keyserver.c (keyserver_import_pka): Use the

same API as the other auto-key-locate fetchers.

* getkey.c (get_pubkey_byname): Use the fingerprint of the key that we
actually fetched.  This helps prevent problems where the key that we
fetched doesn't have the same name that we used to fetch it.  In the
case of CERT and PKA, this is an actual security requirement as the
URL might point to a key put in by an attacker.  By forcing the use of
the fingerprint, we won't use the attacker's key here.

4 files changed, 61 insertions, 31 deletions

diff --git a/g10/ChangeLog b/g10/ChangeLog
index 2f7bee308..d3df2552b 100644
--- a/g10/ChangeLog
+++ b/g10/ChangeLog
@@ -1,5 +1,16 @@
 2006-03-13  David Shaw  <[email protected]>
 
+	* keyserver-internal.h, keyserver.c (keyserver_import_pka): Use
+	the same API as the other auto-key-locate fetchers.
+
+	* getkey.c (get_pubkey_byname): Use the fingerprint of the key
+	that we actually fetched.  This helps prevent problems where the
+	key that we fetched doesn't have the same name that we used to
+	fetch it.  In the case of CERT and PKA, this is an actual security
+	requirement as the URL might point to a key put in by an attacker.
+	By forcing the use of the fingerprint, we won't use the attacker's
+	key here.
+
 	* keyserver-internal.h, keyserver.c (keyserver_spawn,
 	keyserver_work, keyserver_import_cert, keyserver_import_name,
 	keyserver_import_ldap): Pass fingerprint info through.
diff --git a/g10/getkey.c b/g10/getkey.c
index 1805eb041..8594ad9e6 100644
--- a/g10/getkey.c
+++ b/g10/getkey.c
@@ -922,11 +922,14 @@ get_pubkey_byname (PKT_public_key *pk,
 
       for(akl=opt.auto_key_locate;akl;akl=akl->next)
 	{
+	  unsigned char *fpr;
+	  size_t fpr_len;
+
 	  switch(akl->type)
 	    {
 	    case AKL_CERT:
 	      glo_ctrl.in_auto_key_retrieve++;
-	      res=keyserver_import_cert(name,NULL,NULL);
+	      res=keyserver_import_cert(name,&fpr,&fpr_len);
 	      glo_ctrl.in_auto_key_retrieve--;
 
 	      if(res==0)
@@ -935,35 +938,17 @@ get_pubkey_byname (PKT_public_key *pk,
 	      break;
 
 	    case AKL_PKA:
-	      {
-		unsigned char fpr[MAX_FINGERPRINT_LEN];
-
-		glo_ctrl.in_auto_key_retrieve++;
-		res=keyserver_import_pka(name,fpr);
-		glo_ctrl.in_auto_key_retrieve--;
-
-		if(res==0)
-		  {
-		    int i;
-		    char fpr_string[MAX_FINGERPRINT_LEN*2+1];
-
-		    log_info(_("Automatically retrieved `%s' via %s\n"),
-			     name,"PKA");
-
-		    free_strlist(namelist);
-		    namelist=NULL;
-
-		    for(i=0;i<MAX_FINGERPRINT_LEN;i++)
-		      sprintf(fpr_string+2*i,"%02X",fpr[i]);
+	      glo_ctrl.in_auto_key_retrieve++;
+	      res=keyserver_import_pka(name,&fpr,&fpr_len);
 
-		    add_to_strlist( &namelist, fpr_string );
-		  }
-	      }
+	      if(res==0)
+		log_info(_("Automatically retrieved `%s' via %s\n"),
+			 name,"PKA");
 	      break;
 
 	    case AKL_LDAP:
 	      glo_ctrl.in_auto_key_retrieve++;
-	      res=keyserver_import_ldap(name,NULL,NULL);
+	      res=keyserver_import_ldap(name,&fpr,&fpr_len);
 	      glo_ctrl.in_auto_key_retrieve--;
 
 	      if(res==0)
@@ -979,7 +964,7 @@ get_pubkey_byname (PKT_public_key *pk,
 	      if(opt.keyserver)
 		{
 		  glo_ctrl.in_auto_key_retrieve++;
-		  res=keyserver_import_name(name,NULL,NULL,opt.keyserver);
+		  res=keyserver_import_name(name,&fpr,&fpr_len,opt.keyserver);
 		  glo_ctrl.in_auto_key_retrieve--;
 
 		  if(res==0)
@@ -994,7 +979,7 @@ get_pubkey_byname (PKT_public_key *pk,
 
 		keyserver=keyserver_match(akl->spec);
 		glo_ctrl.in_auto_key_retrieve++;
-		res=keyserver_import_name(name,NULL,NULL,keyserver);
+		res=keyserver_import_name(name,&fpr,&fpr_len,keyserver);
 		glo_ctrl.in_auto_key_retrieve--;
 
 		if(res==0)
@@ -1004,6 +989,34 @@ get_pubkey_byname (PKT_public_key *pk,
 	      break;
 	    }
 
+	  /* Use the fingerprint of the key that we actually fetched.
+	     This helps prevent problems where the key that we fetched
+	     doesn't have the same name that we used to fetch it.  In
+	     the case of CERT and PKA, this is an actual security
+	     requirement as the URL might point to a key put in by an
+	     attacker.  By forcing the use of the fingerprint, we
+	     won't use the attacker's key here. */
+	  if(res==0 && fpr)
+	    {
+	      int i;
+	      char fpr_string[MAX_FINGERPRINT_LEN*2+1];
+
+	      assert(fpr_len<=MAX_FINGERPRINT_LEN);
+
+	      free_strlist(namelist);
+	      namelist=NULL;
+
+	      for(i=0;i<fpr_len;i++)
+		sprintf(fpr_string+2*i,"%02X",fpr[i]);
+
+	      if(opt.verbose)
+		log_info("auto-key-locate found fingerprint %s\n",fpr_string);
+
+	      add_to_strlist( &namelist, fpr_string );
+
+	      xfree(fpr);
+	    }
+
 	  rc = key_byname( NULL, namelist, pk, NULL, 0,
 			   include_unusable, ret_keyblock, ret_kdbhd);
 	  if(rc!=G10ERR_NO_PUBKEY)
diff --git a/g10/keyserver-internal.h b/g10/keyserver-internal.h
index 9b6def872..a36598695 100644
--- a/g10/keyserver-internal.h
+++ b/g10/keyserver-internal.h
@@ -45,7 +45,7 @@ int keyserver_search(STRLIST tokens);
 int keyserver_fetch(STRLIST urilist);
 int keyserver_import_cert(const char *name,
 			  unsigned char **fpr,size_t *fpr_len);
-int keyserver_import_pka(const char *name,unsigned char *fpr);
+int keyserver_import_pka(const char *name,unsigned char **fpr,size_t *fpr_len);
 int keyserver_import_name(const char *name,unsigned char **fpr,size_t *fpr_len,
 			  struct keyserver_spec *keyserver);
 int keyserver_import_ldap(const char *name,
diff --git a/g10/keyserver.c b/g10/keyserver.c
index b4a8c14ac..31037c01d 100644
--- a/g10/keyserver.c
+++ b/g10/keyserver.c
@@ -2036,24 +2036,30 @@ keyserver_import_cert(const char *name,unsigned char **fpr,size_t *fpr_len)
 /* Import key pointed to by a PKA record. Return the requested
    fingerprint in fpr. */
 int
-keyserver_import_pka(const char *name,unsigned char *fpr)
+keyserver_import_pka(const char *name,unsigned char **fpr,size_t *fpr_len)
 {
   char *uri;
   int rc=-1;
 
-  uri = get_pka_info (name, fpr);
+  *fpr=xmalloc(20);
+  *fpr_len=20;
+
+  uri = get_pka_info (name, *fpr);
   if (uri)
     {
       struct keyserver_spec *spec;
       spec = parse_keyserver_uri (uri, 1, NULL, 0);
       if (spec)
 	{
-	  rc=keyserver_import_fprint (fpr, 20, spec);
+	  rc=keyserver_import_fprint (*fpr, 20, spec);
 	  free_keyserver_spec (spec);
 	}
       xfree (uri);
     }
 
+  if(rc!=0)
+    xfree(*fpr);
+
   return rc;
 }