From 26e522bab39c8c0260d855fcd067862e24712d49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=96=9F=E9=85=8C=20=E9=B5=AC=E5=85=84?= <tgckpg@gmail.com>
Date: Wed, 31 Aug 2022 21:59:22 +0800
Subject: [PATCH] Initial commit

---
 signin.js | 190 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 190 insertions(+)
 create mode 100644 signin.js

diff --git a/signin.js b/signin.js
new file mode 100644
index 0000000..2cd2a9a
--- /dev/null
+++ b/signin.js
@@ -0,0 +1,190 @@
+"use strict";
+
+const cl = global.botanLoader;
+const Dragonfly = global.Dragonfly;
+
+const crypto = require( "crypto" );
+const util = require( "util" );
+const EventEmitter = require( "events" ).EventEmitter;
+const http = require( "http" );
+const HttpRequest = cl.load( "botanss.net.HttpRequest" );
+
+class SignInEventArgs
+{
+	constructor({ message, redirect, data = [], success = false } = {})
+	{
+		this.success = success;
+		this._message = message;
+		this._redirect = redirect;
+		this.data = data
+	}
+
+	get message()
+	{
+		return this._message;
+	}
+
+	get location()
+	{
+		return this._redirect + "?" + this.data.join( "&" );
+	}
+}
+
+class Signin extends EventEmitter
+{
+	constructor( conf )
+	{
+		super();
+		this.conf = conf;
+		this.spec = null;
+	}
+
+	Start( action, params, handler )
+	{
+		var request = new HttpRequest( this.conf.spec );
+		var _self = this;
+
+		if( this.spec )
+		{
+			_self[ action ]( params, handler );
+		}
+		else
+		{
+			request.addListener( "RequestComplete", function( sender, e )
+			{
+				if( e.statusCode == 200 )
+				{
+					_self.spec = JSON.parse( e.ResponseString );
+					_self[ action ]( params, handler );
+				}
+			} );
+			request.Send();
+		}
+	}
+
+	ValidateAzureAD( params, handler )
+	{
+		if( !this.spec )
+			throw new Error( "OpenID spec is not present" );
+
+		var _self = this;
+
+		var jwt = params[ "id_token" ];
+		if( !jwt )
+		{
+			handler( this, new SignInEventArgs({
+				"message": params[ "error_description" ]
+			}) );
+			return;
+		}
+
+		var [ jHeader, jPayload, jSig ] = jwt.split( "." );
+
+		var header = JSON.parse( Buffer.from( jHeader, "base64" ) );
+		var payload = JSON.parse( Buffer.from( jPayload, "base64" ) );
+
+		var aud = payload[ "aud" ];
+		var clientId = this.conf.authorization_endpoint_params.client_id;
+
+		if( aud !== clientId )
+		{
+			handler( this, new SignInEventArgs({ message: `aud mismatched: ${aud}` }) );
+			return;
+		}
+
+		var [ url, data ] = this._endPointRes( "jwks_uri" );
+
+		var request = new HttpRequest( url + "?" + data.join( "&" ) );
+		request.addListener( "RequestComplete", function( sender, e )
+		{
+			var eArgs;
+
+			if( e.statusCode == 200 )
+			{
+				var respJson = JSON.parse( e.ResponseString );
+				var keyId = header[ "kid" ];
+
+				for( let key of respJson[ "keys" ] )
+				{
+					if( key[ "kid" ] === keyId )
+					{
+						var hashFunc = crypto.createVerify({
+							"RS256": "RSA-SHA256"
+						}[ header[ "alg" ] ]);
+
+						hashFunc.write( `${jHeader}.${jPayload}` );
+						hashFunc.end();
+
+						var pub = crypto.createPublicKey({
+							"key": {
+								"kty": key["kty"]
+								, "n": key["n"]
+								, "e": key["e"]
+							}, "format": "jwk"
+						});
+
+						eArgs = new SignInEventArgs(
+						{
+							"success": hashFunc.verify( pub, jSig, "base64" )
+							, "data": payload
+						});
+						break;
+					}
+				}
+
+				eArgs = eArgs || new SignInEventArgs({
+					"message": `Unable to find key: ${keyId}`
+				});
+			}
+			else
+			{
+				eArgs = new SignInEventArgs({
+					"message": `Remote returned ${e.statusCode}`
+				});
+			}
+
+			handler( _self, eArgs );
+		});
+
+		request.Send();
+	}
+
+	Authorize( params, handler )
+	{
+		var [ url, data ] = this._endPointRes( "authorization_endpoint" );
+		var eArgs = new SignInEventArgs({ "redirect": url, "data": data });
+		handler( this, eArgs );
+	}
+
+	_endPointRes( endpoint, handler )
+	{
+		if( !this.spec )
+			throw new Error( "OpenID spec is not present" );
+
+		var url = this.spec[ endpoint ];
+		if( !url )
+			throw new Error( "No such endpoint" );
+
+		var params = this.conf[ endpoint + "_params" ];
+		var requestData = [];
+
+		if( params )
+		{
+			for( var name in params )
+			{
+				var val = params[ name ];
+
+				if( val[0] == "{" )
+				{
+					val = this[ val.replace( "{", "" ).replace( "}", "" ) ]();
+				}
+
+				requestData.push( name + "=" + encodeURIComponent( val ) );
+			}
+		}
+
+		return [ url, requestData ];
+	}
+}
+
+module.exports = Signin;