gracefully handle reformatting keys with no subkey packets

src/key.js

@@ -1272,6 +1272,9 @@ export function reformat(options) {
         options.subkeyType = secretSubkeyPacket.algorithm;
       }
     }
+    if (!secretKeyPacket) {
+      throw new Error('Key does not contain a secret key packet');
+    }
     return wrapKeyObject(secretKeyPacket, secretSubkeyPacket, options);
   });
 }
@@ -1280,8 +1283,10 @@ async function wrapKeyObject(secretKeyPacket, secretSubkeyPacket, options) {
   // set passphrase protection
   if (options.passphrase) {
     secretKeyPacket.encrypt(options.passphrase);
+    if (secretSubkeyPacket) {
       secretSubkeyPacket.encrypt(options.passphrase);
     }
+  }
 
   var packetlist = new packet.List();
 
@@ -1336,6 +1341,7 @@ async function wrapKeyObject(secretKeyPacket, secretSubkeyPacket, options) {
     });
   });
 
+  if (secretSubkeyPacket) {
     var dataToSign = {};
     dataToSign.key = secretKeyPacket;
     dataToSign.bind = secretSubkeyPacket;
@@ -1352,11 +1358,14 @@ async function wrapKeyObject(secretKeyPacket, secretSubkeyPacket, options) {
 
     packetlist.push(secretSubkeyPacket);
     packetlist.push(subkeySignaturePacket);
+  }
 
   if (!options.unlocked) {
     secretKeyPacket.clearPrivateParams();
+    if (secretSubkeyPacket) {
       secretSubkeyPacket.clearPrivateParams();
     }
+  }
 
   return new Key(packetlist);
 }

src/openpgp.js

@@ -126,6 +126,7 @@ export function generateKey({ userIds=[], passphrase, numBits=2048, unlocked=fal
 
 /**
  * Reformats signature packets for a key and rewraps key object.
+ * @param  {Key} privateKey          private key to reformat
  * @param  {Array<Object>} userIds   array of user IDs e.g. [{ name:'Phil Zimmermann', email:'phil@openpgp.org' }]
  * @param  {String} passphrase       (optional) The passphrase used to encrypt the resulting private key
  * @param  {Boolean} unlocked        (optional) If the returned secret part of the generated key is unlocked