Enable Curve25519 in host and client for PIN-based and third-party auth.

remoting/protocol/negotiating_authenticator_base.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_PROTOCOL_NEGOTIATING_AUTHENTICATOR_BASE_H_
 #define REMOTING_PROTOCOL_NEGOTIATING_AUTHENTICATOR_BASE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 48 matching lines @@
 //      another method from the client's supported methods list.
 //  * The host never sends its own supported methods back to the client, so once
 //      the host picks a method from the client's list, it's final.
 //  * Any change in this class must maintain compatibility between any version
 //      mix of webapp, client plugin and host, for both Me2Me and IT2Me.
 class NegotiatingAuthenticatorBase : public Authenticator {
  public:
   // Method represents an authentication algorithm.
   enum class Method {
     INVALID,
-    SPAKE2_SHARED_SECRET_PLAIN,
-    SPAKE2_SHARED_SECRET_HMAC,
-    SPAKE2_PAIR,
-    THIRD_PARTY,
+
+    // SPAKE2 with P224 using access code in plain-text. Used for It2Me.
+    // TODO(sergeyu): Remove and use SHARED_SECRET_SPAKE2_CURVE25519.
+    SHARED_SECRET_PLAIN_SPAKE2_P224,
+
+    // SPAKE2 PIN or access code hashed with host_id using HMAC-SHA256.
+    SHARED_SECRET_SPAKE2_P224,
+    SHARED_SECRET_SPAKE2_CURVE25519,
+
+    // SPAKE2 using shared pairing secret. Falls back to PIN-based
+    // authentication when pairing fails.
+    // TODO(sergeyu): Add CURVE25519 variant. crbug.com/593123
+    PAIRED_SPAKE2_P224,
+
+    // Authentication using third-party authentication server.
+    // SPAKE2 with P224 using shared pairing secret. Falls back to PIN-based
+    // authentication when it fails to authenticate using paired secret.
+    THIRD_PARTY_SPAKE2_P224,
+    THIRD_PARTY_SPAKE2_CURVE25519,
   };
 
   ~NegotiatingAuthenticatorBase() override;
 
   // Authenticator interface.
   State state() const override;
   bool started() const override;
   RejectionReason rejection_reason() const override;
   const std::string& GetAuthKey() const override;
   scoped_ptr<ChannelAuthenticator> CreateChannelAuthenticator() const override;
@@ skipping 37 matching lines @@
   RejectionReason rejection_reason_ = INVALID_CREDENTIALS;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NegotiatingAuthenticatorBase);
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_NEGOTIATING_AUTHENTICATOR_BASE_H_