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(SPAKE2, hash_function);
 }
 
 // static
+AuthenticationMethod AuthenticationMethod::ThirdParty() {
+  return AuthenticationMethod(THIRD_PARTY, NONE);
+}
+
+// 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 15 matching lines @@
 
       return std::string(out_bytes, out_bytes + sizeof(out_bytes));
     }
   }
 
   NOTREACHED();
   return shared_secret;
 }
 
 AuthenticationMethod::AuthenticationMethod()
-    : invalid_(true),
+    : method_type_(INVALID),
       hash_function_(NONE) {
 }
 
-AuthenticationMethod::AuthenticationMethod(HashFunction hash_function)
-    : invalid_(false),
+AuthenticationMethod::AuthenticationMethod(MethodType method_type,
+                                           HashFunction hash_function)
+    : method_type_(method_type),
       hash_function_(hash_function) {
 }

[Sergey Ulanov, 2013/03/22 05:58:43]

DCHECK_NE(type_, INVALID);

[rmsousa, 2013/03/22 21:19:05]

Done.

 
 AuthenticationMethod::HashFunction AuthenticationMethod::hash_function() const {
   DCHECK(is_valid());
   return hash_function_;
 }
 
 const std::string AuthenticationMethod::ToString() const {
   DCHECK(is_valid());
 
+  if (method_type_ == THIRD_PARTY)
+    return "third_party";
+
+  DCHECK(method_type_ == SPAKE2);

[Sergey Ulanov, 2013/03/22 05:58:43]

nit: DCHECK_EQ

[rmsousa, 2013/03/22 21:19:05]

Done.

+
   switch (hash_function_) {
     case NONE:
       return "spake2_plain";
     case HMAC_SHA256:
       return "spake2_hmac";
+    default:

[Sergey Ulanov, 2013/03/22 05:58:43]

You should not have default case when there is a case for each enum value (it
breaks the warning about not handled values when new enum values are added).

[rmsousa, 2013/03/22 21:19:05]

Done.

+      NOTREACHED();
   }
 
-  NOTREACHED();
-  return "";
+  return "invalid";

[Sergey Ulanov, 2013/03/22 05:58:43]

Why do we need to return non-empty string here?

[rmsousa, 2013/03/22 21:19:05]

No functional reason, it just makes it slightly easier to debug (LOG(ERROR) <<
method.ToString()).

 }
 
 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 method_type_ == other.method_type_ &&
+      hash_function_ == other.hash_function_;
 }
 
 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;
   }
 
   return true;
 }
 
 }  // namespace protocol
 }  // namespace remoting