Fix generating keys with a date in the future

This was broken in 8c3bcd1.

(Before then, the revocation certificate was already broken when
generating a key with a date in the future.)

src/key/key.js

@@ -664,12 +664,13 @@ Key.prototype.revoke = async function({
 /**
  * Get revocation certificate from a revoked key.
  *   (To get a revocation certificate for an unrevoked key, call revoke() first.)
+ * @param  {Date} date Use the given date instead of the current time
  * @returns {Promise<String>} armored revocation certificate
  * @async
  */
-Key.prototype.getRevocationCertificate = async function() {
+Key.prototype.getRevocationCertificate = async function(date = new Date()) {
   const dataToVerify = { key: this.keyPacket };
-  const revocationSignature = await helper.getLatestValidSignature(this.revocationSignatures, this.keyPacket, enums.signature.key_revocation, dataToVerify);
+  const revocationSignature = await helper.getLatestValidSignature(this.revocationSignatures, this.keyPacket, enums.signature.key_revocation, dataToVerify, date);
   const packetlist = new packet.List();
   packetlist.push(revocationSignature);
   return armor.encode(enums.armor.public_key, packetlist.write(), null, null, 'This is a revocation certificate');

src/openpgp.js

@@ -136,7 +136,7 @@ export function generateKey({ userIds = [], passphrase = "", numBits = 2048, rsa
   }
 
   return generate(options).then(async key => {
-    const revocationCertificate = await key.getRevocationCertificate();
+    const revocationCertificate = await key.getRevocationCertificate(date);
     key.revocationSignatures = [];
 
     return convertStreams({
@@ -172,7 +172,7 @@ export function reformatKey({ privateKey, userIds = [], passphrase = "", keyExpi
   options.revoked = options.revocationCertificate;
 
   return reformat(options).then(async key => {
-    const revocationCertificate = await key.getRevocationCertificate();
+    const revocationCertificate = await key.getRevocationCertificate(date);
     key.revocationSignatures = [];
 
     return convertStreams({

test/general/key.js

@@ -1972,7 +1972,25 @@ function versionSpecificTests() {
       expect(+newKey.key.subKeys[0].getCreationTime()).to.equal(+past);
       expect(+newKey.key.subKeys[0].bindingSignatures[0].created).to.equal(+past);
     });
-  })
+  });
+
+  it('Generate key - setting date to the future', function() {
+    const future = new Date(Math.ceil(Date.now() / 1000) * 1000 + 1000);
+    const opt = {
+      numBits: 512,
+      userIds: { name: 'Test User', email: 'text@example.com' },
+      passphrase: 'secret',
+      date: future
+    };
+    if (openpgp.util.getWebCryptoAll()) { opt.numBits = 2048; } // webkit webcrypto accepts minimum 2048 bit keys
+
+    return openpgp.generateKey(opt).then(function(newKey) {
+      expect(newKey.key).to.exist;
+      expect(+newKey.key.getCreationTime()).to.equal(+future);
+      expect(+newKey.key.subKeys[0].getCreationTime()).to.equal(+future);
+      expect(+newKey.key.subKeys[0].bindingSignatures[0].created).to.equal(+future);
+    });
+  });
 
   it('Generate key - multi userid', function() {
     const userId1 = 'test <a@b.com>';