move auth code from zenserver into zenhttp (#265)

this code should be usable outside of zenserver, so this moves it out into zenhttp where it can be used from lower level components

1 files changed, 127 insertions, 0 deletions

diff --git a/src/zenhttp/auth/oidc.cpp b/src/zenhttp/auth/oidc.cpp
new file mode 100644
index 000000000..318110c7d
--- /dev/null
+++ b/src/zenhttp/auth/oidc.cpp
@@ -0,0 +1,127 @@
+// Copyright Epic Games, Inc. All Rights Reserved.
+
+#include "zenhttp/auth/oidc.h"
+
+ZEN_THIRD_PARTY_INCLUDES_START
+#include <cpr/cpr.h>
+#include <fmt/format.h>
+#include <json11.hpp>
+ZEN_THIRD_PARTY_INCLUDES_END
+
+namespace zen {
+
+namespace details {
+
+	using StringArray = std::vector<std::string>;
+
+	StringArray ToStringArray(const json11::Json JsonArray)
+	{
+		StringArray Result;
+
+		const auto& Items = JsonArray.array_items();
+
+		for (const auto& Item : Items)
+		{
+			Result.push_back(Item.string_value());
+		}
+
+		return Result;
+	}
+
+}  // namespace details
+
+using namespace std::literals;
+
+OidcClient::OidcClient(const OidcClient::Options& Options)
+{
+	m_BaseUrl  = std::string(Options.BaseUrl);
+	m_ClientId = std::string(Options.ClientId);
+}
+
+OidcClient::InitResult
+OidcClient::Initialize()
+{
+	ExtendableStringBuilder<256> Uri;
+	Uri << m_BaseUrl << "/.well-known/openid-configuration"sv;
+
+	cpr::Session Session;
+
+	Session.SetOption(cpr::Url{Uri.c_str()});
+
+	cpr::Response Response = Session.Get();
+
+	if (Response.error)
+	{
+		return {.Reason = std::move(Response.error.message)};
+	}
+
+	if (Response.status_code != 200)
+	{
+		return {.Reason = std::move(Response.reason)};
+	}
+
+	std::string	 JsonError;
+	json11::Json Json = json11::Json::parse(Response.text, JsonError);
+
+	if (JsonError.empty() == false)
+	{
+		return {.Reason = std::move(JsonError)};
+	}
+
+	m_Config = {.Issuer							   = Json["issuer"].string_value(),
+				.AuthorizationEndpoint			   = Json["authorization_endpoint"].string_value(),
+				.TokenEndpoint					   = Json["token_endpoint"].string_value(),
+				.UserInfoEndpoint				   = Json["userinfo_endpoint"].string_value(),
+				.RegistrationEndpoint			   = Json["registration_endpoint"].string_value(),
+				.JwksUri						   = Json["jwks_uri"].string_value(),
+				.SupportedResponseTypes			   = details::ToStringArray(Json["response_types_supported"]),
+				.SupportedResponseModes			   = details::ToStringArray(Json["response_modes_supported"]),
+				.SupportedGrantTypes			   = details::ToStringArray(Json["grant_types_supported"]),
+				.SupportedScopes				   = details::ToStringArray(Json["scopes_supported"]),
+				.SupportedTokenEndpointAuthMethods = details::ToStringArray(Json["token_endpoint_auth_methods_supported"]),
+				.SupportedClaims				   = details::ToStringArray(Json["claims_supported"])};
+
+	return {.Ok = true};
+}
+
+OidcClient::RefreshTokenResult
+OidcClient::RefreshToken(std::string_view RefreshToken)
+{
+	const std::string Body = fmt::format("grant_type=refresh_token&refresh_token={}&client_id={}", RefreshToken, m_ClientId);
+
+	cpr::Session Session;
+
+	Session.SetOption(cpr::Url{m_Config.TokenEndpoint.c_str()});
+	Session.SetOption(cpr::Header{{"Content-Type", "application/x-www-form-urlencoded"}});
+	Session.SetBody(cpr::Body{Body.data(), Body.size()});
+
+	cpr::Response Response = Session.Post();
+
+	if (Response.error)
+	{
+		return {.Reason = std::move(Response.error.message)};
+	}
+
+	if (Response.status_code != 200)
+	{
+		return {.Reason = fmt::format("{} ({})", Response.reason, Response.text)};
+	}
+
+	std::string	 JsonError;
+	json11::Json Json = json11::Json::parse(Response.text, JsonError);
+
+	if (JsonError.empty() == false)
+	{
+		return {.Reason = std::move(JsonError)};
+	}
+
+	return {.TokenType		  = Json["token_type"].string_value(),
+			.AccessToken	  = Json["access_token"].string_value(),
+			.RefreshToken	  = Json["refresh_token"].string_value(),
+			.IdentityToken	  = Json["id_token"].string_value(),
+			.Scope			  = Json["scope"].string_value(),
+			.ExpiresInSeconds = static_cast<int64_t>(Json["expires_in"].int_value()),
+			.Ok				  = true};
+}
+
+}  // namespace zen