Third Party authentication protocol.

remoting/protocol/authentication_method.cc

Index: remoting/protocol/authentication_method.cc
diff --git a/remoting/protocol/authentication_method.cc b/remoting/protocol/authentication_method.cc
index ab60f399535289f9e5084b7d646519a85e91fd1d..71ec00880a9a88fecbca5d33c440f5e80572b59e 100644
--- a/remoting/protocol/authentication_method.cc
+++ b/remoting/protocol/authentication_method.cc
@@ -19,7 +19,12 @@ AuthenticationMethod AuthenticationMethod::Invalid() {
 
 // 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
@@ -29,6 +34,8 @@ AuthenticationMethod AuthenticationMethod::FromString(
     return Spake2(NONE);
   } else if (value == "spake2_hmac") {
     return Spake2(HMAC_SHA256);
+  } else if (value == "third_party") {
+    return ThirdParty();
   } else {
     return AuthenticationMethod::Invalid();
   }
@@ -64,13 +71,15 @@ std::string AuthenticationMethod::ApplyHashFunction(
 }
 
 AuthenticationMethod::AuthenticationMethod()
-    : invalid_(true),
+    : type_(INVALID),
       hash_function_(NONE) {
 }
 
-AuthenticationMethod::AuthenticationMethod(HashFunction hash_function)
-    : invalid_(false),
+AuthenticationMethod::AuthenticationMethod(MethodType type,
+                                           HashFunction hash_function)
+    : type_(type),
       hash_function_(hash_function) {
+  DCHECK_NE(type_, INVALID);
 }
 
 AuthenticationMethod::HashFunction AuthenticationMethod::hash_function() const {
@@ -81,6 +90,11 @@ AuthenticationMethod::HashFunction AuthenticationMethod::hash_function() const {
 const std::string AuthenticationMethod::ToString() const {
   DCHECK(is_valid());
 
+  if (type_ == THIRD_PARTY)
+    return "third_party";
+
+  DCHECK_EQ(type_, SPAKE2);
+
   switch (hash_function_) {
     case NONE:
       return "spake2_plain";
@@ -88,17 +102,13 @@ const std::string AuthenticationMethod::ToString() const {
       return "spake2_hmac";
   }
 
-  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 type_ == other.type_ &&
+      hash_function_ == other.hash_function_;
 }
 
 bool SharedSecretHash::Parse(const std::string& as_string) {