From dbe635f721ccd89b3d8f36f63a0f0f3e73685453 Mon Sep 17 00:00:00 2001
From: Matthew Chen <matthew@signal.org>
Date: Wed, 24 Oct 2018 20:25:17 -0400
Subject: [PATCH] Try random UD access keys in profile gets.

---
 .../profiles/ProfileFetcherJob.swift          | 30 +++++++++++--
 .../src/Messages/OWSMessageSend.swift         |  2 +-
 .../src/Messages/UD/OWSUDManager.swift        | 43 +++++++++----------
 .../src/Network/UnidentifiedAccess.swift      | 11 -----
 4 files changed, 49 insertions(+), 37 deletions(-)

diff --git a/SignalMessaging/profiles/ProfileFetcherJob.swift b/SignalMessaging/profiles/ProfileFetcherJob.swift
index 7d4830e1a..5955fa13c 100644
--- a/SignalMessaging/profiles/ProfileFetcherJob.swift
+++ b/SignalMessaging/profiles/ProfileFetcherJob.swift
@@ -134,7 +134,29 @@ public class ProfileFetcherJob: NSObject {
 
         Logger.error("getProfile: \(recipientId)")
 
-        let unidentifiedAccess: SSKUnidentifiedAccess? = self.getUnidentifiedAccess(forRecipientId: recipientId)
+        // If we are in unknown mode, try using a random UD access key
+        // in case they support unrestricted access.
+        if self.udManager.unidentifiedAccessMode(recipientId: recipientId) == .unknown,
+            let randomUnidentifiedAccess = self.udManager.getRandomAccess() {
+            return requestProfile(recipientId: recipientId,
+                                  unidentifiedAccess: randomUnidentifiedAccess)
+                .recover { (_: Error) -> Promise<SignalServiceProfile> in
+                    Logger.verbose("Failing over to non-random access.")
+                    let unidentifiedAccess = self.getUnidentifiedAccess(forRecipientId: recipientId)
+                    return self.requestProfile(recipientId: recipientId,
+                                               unidentifiedAccess: unidentifiedAccess)
+            }
+        } else {
+            let unidentifiedAccess = getUnidentifiedAccess(forRecipientId: recipientId)
+            return requestProfile(recipientId: recipientId,
+                                  unidentifiedAccess: unidentifiedAccess)
+        }
+    }
+
+    private func requestProfile(recipientId: String,
+                                unidentifiedAccess: SSKUnidentifiedAccess?) -> Promise<SignalServiceProfile> {
+        AssertIsOnMainThread()
+
         let requestMaker = RequestMaker(requestFactoryBlock: { (unidentifiedAccessForRequest) -> TSRequest in
             return OWSRequestFactory.getProfileRequest(recipientId: recipientId, unidentifiedAccess: unidentifiedAccessForRequest)
         }, udAuthFailureBlock: {
@@ -158,7 +180,9 @@ public class ProfileFetcherJob: NSObject {
                                      profileNameEncrypted: signalServiceProfile.profileNameEncrypted,
                                      avatarUrlPath: signalServiceProfile.avatarUrlPath)
 
-        updateUnidentifiedAccess(recipientId: recipientId, verifier: signalServiceProfile.unidentifiedAccessVerifier, hasUnrestrictedAccess: signalServiceProfile.hasUnrestrictedUnidentifiedAccess)
+        updateUnidentifiedAccess(recipientId: recipientId,
+                                 verifier: signalServiceProfile.unidentifiedAccessVerifier,
+                                 hasUnrestrictedAccess: signalServiceProfile.hasUnrestrictedUnidentifiedAccess)
     }
 
     private func updateUnidentifiedAccess(recipientId: String, verifier: Data?, hasUnrestrictedAccess: Bool) {
@@ -207,6 +231,6 @@ public class ProfileFetcherJob: NSObject {
     }
 
     private func getUnidentifiedAccess(forRecipientId recipientId: RecipientIdentifier) -> SSKUnidentifiedAccess? {
-        return self.udManager.getAccess(forRecipientId: recipientId)?.targetUnidentifiedAccess
+        return self.udManager.getAccess(forRecipientId: recipientId)
     }
 }
diff --git a/SignalServiceKit/src/Messages/OWSMessageSend.swift b/SignalServiceKit/src/Messages/OWSMessageSend.swift
index 6832f53ee..93d07cb63 100644
--- a/SignalServiceKit/src/Messages/OWSMessageSend.swift
+++ b/SignalServiceKit/src/Messages/OWSMessageSend.swift
@@ -61,7 +61,7 @@ public class OWSMessageSend: NSObject {
         self.localNumber = localNumber
 
         if let recipientId = recipient.uniqueId {
-            self.unidentifiedAccess = udManager.getAccess(forRecipientId: recipientId)?.targetUnidentifiedAccess
+            self.unidentifiedAccess = udManager.getAccess(forRecipientId: recipientId)
             self.isLocalNumber = localNumber == recipientId
         } else {
             owsFailDebug("SignalRecipient missing recipientId")
diff --git a/SignalServiceKit/src/Messages/UD/OWSUDManager.swift b/SignalServiceKit/src/Messages/UD/OWSUDManager.swift
index 8718a14e5..a4c7346ba 100644
--- a/SignalServiceKit/src/Messages/UD/OWSUDManager.swift
+++ b/SignalServiceKit/src/Messages/UD/OWSUDManager.swift
@@ -34,7 +34,13 @@ public enum UnidentifiedAccessMode: Int {
     func setUnidentifiedAccessMode(_ mode: UnidentifiedAccessMode, recipientId: String)
 
     @objc
-    func getAccess(forRecipientId recipientId: RecipientIdentifier) -> SSKUnidentifiedAccessPair?
+    func getRandomAccess() -> SSKUnidentifiedAccess?
+
+    @objc
+    func getAccess(forRecipientId recipientId: RecipientIdentifier) -> SSKUnidentifiedAccess?
+
+    @objc
+    func unidentifiedAccessMode(recipientId: RecipientIdentifier) -> UnidentifiedAccessMode
 
     // Returns the UD access key for a given recipient if:
     //
@@ -124,7 +130,18 @@ public class OWSUDManagerImpl: NSObject, OWSUDManager {
     // MARK: - Recipient state
 
     @objc
-    public func getAccess(forRecipientId recipientId: RecipientIdentifier) -> SSKUnidentifiedAccessPair? {
+    public func getRandomAccess() -> SSKUnidentifiedAccess? {
+        guard let ourSenderCertificate = senderCertificate() else {
+            return nil
+        }
+
+        let theirAccessKey = SMKUDAccessKey(randomKeyData: ())
+
+        return SSKUnidentifiedAccess(accessKey: theirAccessKey, senderCertificate: ourSenderCertificate)
+    }
+
+    @objc
+    public func getAccess(forRecipientId recipientId: RecipientIdentifier) -> SSKUnidentifiedAccess? {
         let theirAccessMode = unidentifiedAccessMode(recipientId: recipientId)
         guard theirAccessMode == .enabled || theirAccessMode == .unrestricted else {
             return nil
@@ -138,29 +155,11 @@ public class OWSUDManagerImpl: NSObject, OWSUDManager {
             return nil
         }
 
-        guard let ourAccessKey: SMKUDAccessKey = {
-            if shouldAllowUnrestrictedAccessLocal() {
-                return SMKUDAccessKey(randomKeyData: ())
-            } else {
-                guard let localNumber = tsAccountManager.localNumber() else {
-                    owsFailDebug("localNumber was unexpectedly nil")
-                    return nil
-                }
-
-                return enabledUDAccessKeyForRecipient(localNumber)
-            }
-        }() else {
-            return nil
-        }
-
-        let targetUnidentifiedAccess = SSKUnidentifiedAccess(accessKey: theirAccessKey, senderCertificate: ourSenderCertificate)
-        let selfUnidentifiedAccess = SSKUnidentifiedAccess(accessKey: ourAccessKey, senderCertificate: ourSenderCertificate)
-        return SSKUnidentifiedAccessPair(targetUnidentifiedAccess: targetUnidentifiedAccess,
-                                         selfUnidentifiedAccess: selfUnidentifiedAccess)
+        return SSKUnidentifiedAccess(accessKey: theirAccessKey, senderCertificate: ourSenderCertificate)
     }
 
     @objc
-    func unidentifiedAccessMode(recipientId: RecipientIdentifier) -> UnidentifiedAccessMode {
+    public func unidentifiedAccessMode(recipientId: RecipientIdentifier) -> UnidentifiedAccessMode {
         guard let existingRawValue = dbConnection.object(forKey: recipientId, inCollection: kUnidentifiedAccessCollection) as? Int else {
             return .unknown
         }
diff --git a/SignalServiceKit/src/Network/UnidentifiedAccess.swift b/SignalServiceKit/src/Network/UnidentifiedAccess.swift
index e4ae99fc8..48d7b8b4d 100644
--- a/SignalServiceKit/src/Network/UnidentifiedAccess.swift
+++ b/SignalServiceKit/src/Network/UnidentifiedAccess.swift
@@ -5,17 +5,6 @@
 import Foundation
 import SignalMetadataKit
 
-@objc
-public class SSKUnidentifiedAccessPair: NSObject {
-    public let targetUnidentifiedAccess: SSKUnidentifiedAccess
-    public let selfUnidentifiedAccess: SSKUnidentifiedAccess
-
-    init(targetUnidentifiedAccess: SSKUnidentifiedAccess, selfUnidentifiedAccess: SSKUnidentifiedAccess) {
-        self.targetUnidentifiedAccess = targetUnidentifiedAccess
-        self.selfUnidentifiedAccess = selfUnidentifiedAccess
-    }
-}
-
 @objc
 public class SSKUnidentifiedAccess: NSObject {
     @objc