Third Party authentication protocol.

remoting/protocol/authentication_method.cc

 // 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.
 
 #include "remoting/protocol/authentication_method.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "crypto/hmac.h"
 #include "remoting/protocol/auth_util.h"
 
 namespace remoting {
 namespace protocol {
 
 // static
 AuthenticationMethod AuthenticationMethod::Invalid() {
   return AuthenticationMethod();
 }
 
 // static
 AuthenticationMethod AuthenticationMethod::Spake2(HashFunction hash_function) {
-  return AuthenticationMethod(hash_function);
+  return AuthenticationMethod(hash_function, false);
 }
 
 // static
+AuthenticationMethod AuthenticationMethod::ThirdParty() {
+  return AuthenticationMethod(NONE, true);
+}
+
+// static
 AuthenticationMethod AuthenticationMethod::FromString(
     const std::string& value) {
   if (value == "spake2_plain") {
     return Spake2(NONE);
   } else if (value == "spake2_hmac") {
     return Spake2(HMAC_SHA256);
+  } else if (value == "third_party") {
+    return ThirdParty();
   } else {
     return AuthenticationMethod::Invalid();
   }
 }
 
 // static
 std::string AuthenticationMethod::ApplyHashFunction(
     HashFunction hash_function,
     const std::string& tag,
     const std::string& shared_secret) {
@@ skipping 16 matching lines @@
       return std::string(out_bytes, out_bytes + sizeof(out_bytes));
     }
   }
 
   NOTREACHED();
   return shared_secret;
 }
 
 AuthenticationMethod::AuthenticationMethod()
     : invalid_(true),
+      requires_token_(false),
       hash_function_(NONE) {
 }
 
-AuthenticationMethod::AuthenticationMethod(HashFunction hash_function)
+AuthenticationMethod::AuthenticationMethod(HashFunction hash_function,
+                                           bool requires_token)
     : invalid_(false),
+      requires_token_(requires_token),
       hash_function_(hash_function) {
 }
 
 AuthenticationMethod::HashFunction AuthenticationMethod::hash_function() const {
   DCHECK(is_valid());
   return hash_function_;
 }
 
 const std::string AuthenticationMethod::ToString() const {
   DCHECK(is_valid());
 
+  if (requires_token_) {
+    return "third_party";

[Wez, 2013/03/05 22:55:53]

nit: No need for {} on single-line if.

+  }
+
   switch (hash_function_) {
     case NONE:
       return "spake2_plain";
     case HMAC_SHA256:
       return "spake2_hmac";
+    default:
+      NOTREACHED();
   }
 
-  NOTREACHED();
-  return "";
+  return "invalid";
 }
 
 bool AuthenticationMethod::operator ==(
     const AuthenticationMethod& other) const {
   if (!is_valid())
     return !other.is_valid();
   if (!other.is_valid())
     return false;
-  return hash_function_ == other.hash_function_;
+  return ToString() == other.ToString();

[Wez, 2013/03/05 22:55:53]

nit: This creates two std::strings on every compare, which seems extravagant -
consider comparing the two fields explicitly.

 }
 
 bool SharedSecretHash::Parse(const std::string& as_string) {
   size_t separator = as_string.find(':');
   if (separator == std::string::npos)
     return false;
 
   std::string function_name = as_string.substr(0, separator);
   if (function_name == "plain") {
     hash_function = AuthenticationMethod::NONE;
   } else if (function_name == "hmac") {
     hash_function = AuthenticationMethod::HMAC_SHA256;
   } else {
     return false;
   }
 
   if (!base::Base64Decode(as_string.substr(separator + 1), &value)) {
     return false;

[Wez, 2013/03/05 22:55:53]

nit: This shouldn't have {} either, for consistency.

   }
 
   return true;
 }
 
 }  // namespace protocol
 }  // namespace remoting