Update saveIdentity

Add support new blockingApproval and nonblockingApproval arguments
Populate the firstUse property on identity key records
Return whether an existing record was overwritten.

References
https://github.com/WhisperSystems/Signal-Android/commit/39d4a7#diff-69ede72c549da6bcbcd959935995b7e9R45

// FREEBIE

js/signal_protocol_store.js

@@ -318,7 +318,7 @@
                 });
             });
         },
-        saveIdentity: function(identifier, publicKey) {
+        saveIdentity: function(identifier, publicKey, blockingApproval, nonblockingApproval) {
             if (identifier === null || identifier === undefined) {
                 throw new Error("Tried to put identity key for undefined/null key");
             }
@@ -332,17 +332,41 @@
                     var oldpublicKey = identityKey.get('publicKey');
                     if (!oldpublicKey) {
                         // Lookup failed, or the current key was removed, so save this one.
-                        identityKey.save({publicKey: publicKey}).then(resolve);
+                        console.log("Saving new identity...");
+                        identityKey.save({
+                            publicKey           : publicKey,
+                            firstUse            : true,
+                            timestamp           : Date.now(),
+                            blockingApproval    : blockingApproval,
+                            nonblockingApproval : nonblockingApproval,
+                        }).then(function() {
+                            resolve(false);
+                        });
+                    } else if (!equalArrayBuffers(oldpublicKey, publicKey)) {
+                        console.log("Replacing existing identity...");
+                        identityKey.save({
+                            publicKey           : publicKey,
+                            firstUse            : false,
+                            timestamp           : Date.now(),
+                            blockingApproval    : blockingApproval,
+                            nonblockingApproval : nonblockingApproval,
+                        }).then(function() {
+                            this.trigger('keychange', identifier);
+                            resolve(true);
+                        }.bind(this));
+                    } else if (this.isBlockingApprovalRequired(identityKey) || this.isNonBlockingApprovalRequired(identityKey)) {
+                        console.log("Setting approval status...");
+                        identityKey.save({
+                            blockingApproval    : blockingApproval,
+                            nonblockingApproval : nonblockingApproval,
+                        }).then(function() {
+                            resolve(false);
+                        });
                     } else {
-                        // Key exists, if it matches do nothing, else throw
-                        if (equalArrayBuffers(oldpublicKey, publicKey)) {
-                            resolve();
-                        } else {
-                            reject(new Error("Attempted to overwrite a different identity key"));
-                        }
+                        resolve(false);
                     }
-                });
-            });
+                }.bind(this));
+            }.bind(this));
         },
         isBlockingApprovalRequired: function(identityKey) {
             return (!identityKey.get('firstUse')

test/storage_test.js

@@ -43,16 +43,14 @@ describe("SignalProtocolStore", function() {
                 });
             }).then(done,done);
         });
-        it('rejects on key change', function(done) {
+        it('returns true on key change', function(done) {
             var newIdentity = libsignal.crypto.getRandomBytes(33);
             store.saveIdentity(identifier, testKey.pubKey).then(function() {
-                store.saveIdentity(identifier, newIdentity).then(function() {
-                    done(new Error('Allowed to overwrite identity key'));
-                }).catch(function(e) {
-                    assert(e instanceof Error);
+                store.saveIdentity(identifier, newIdentity).then(function(changed) {
+                    assert.isTrue(changed);
                     done();
                 });
-            });
+            }).catch(done);
         });
     });
     describe('isTrustedIdentity', function() {