/js/lib/Socket.IO-node/support/socket.io-client/lib/vendor/web-socket-js/flash-src/com/hurlant/crypto/cert/X509Certificate.as

/**

 * X509Certificate

 * 

 * A representation for a X509 Certificate, with

 * methods to parse, verify and sign it.

 * Copyright (c) 2007 Henri Torgemane

 * 

 * See LICENSE.txt for full license information.

 */

package com.hurlant.crypto.cert {

	import com.hurlant.crypto.hash.IHash;

	import com.hurlant.crypto.hash.MD2;

	import com.hurlant.crypto.hash.MD5;

	import com.hurlant.crypto.hash.SHA1;

	import com.hurlant.crypto.rsa.RSAKey;

	import com.hurlant.util.ArrayUtil;

	import com.hurlant.util.Base64;

	import com.hurlant.util.der.ByteString;

	import com.hurlant.util.der.DER;

	import com.hurlant.util.der.OID;

	import com.hurlant.util.der.ObjectIdentifier;

	import com.hurlant.util.der.PEM;

	import com.hurlant.util.der.PrintableString;

	import com.hurlant.util.der.Sequence;

	import com.hurlant.util.der.Type;

	

	import flash.utils.ByteArray;

	

	public class X509Certificate {

		private var _loaded:Boolean;

		private var _param:*;

		private var _obj:Object;

		public function X509Certificate(p:*) {

			_loaded = false;

			_param = p;

			// lazy initialization, to avoid unnecessary parsing of every builtin CA at start-up.

		}

		private function load():void {

			if (_loaded) return;

			var p:* = _param;

			var b:ByteArray;

			if (p is String) {

				b = PEM.readCertIntoArray(p as String);

			} else if (p is ByteArray) {

				b = p;

			}

			if (b!=null) {

				_obj = DER.parse(b, Type.TLS_CERT);

				_loaded = true;

			} else {

				throw new Error("Invalid x509 Certificate parameter: "+p);

			}

		}

		public function isSigned(store:X509CertificateCollection, CAs:X509CertificateCollection, time:Date=null):Boolean {

			load();

			// check timestamps first. cheapest.

			if (time==null) {

				time = new Date;

			}

			var notBefore:Date = getNotBefore();

			var notAfter:Date = getNotAfter();

			if (time.getTime()<notBefore.getTime()) return false; // cert isn't born yet.

			if (time.getTime()>notAfter.getTime()) return false;  // cert died of old age.

			// check signature.

			var subject:String = getIssuerPrincipal();

			// try from CA first, since they're treated better.

			var parent:X509Certificate = CAs.getCertificate(subject);

			var parentIsAuthoritative:Boolean = false;

			if (parent == null) {

				parent = store.getCertificate(subject);

				if (parent == null) {

					return false; // issuer not found

				}

			} else {

				parentIsAuthoritative = true;

			}

			if (parent == this) { // pathological case. avoid infinite loop

				return false; // isSigned() returns false if we're self-signed.

			}

			if (!(parentIsAuthoritative&&parent.isSelfSigned(time)) &&

				!parent.isSigned(store, CAs, time)) {

				return false;

			}

			var key:RSAKey = parent.getPublicKey();

			return verifyCertificate(key);

		}

		public function isSelfSigned(time:Date):Boolean {

			load();

			

			var key:RSAKey = getPublicKey();

			return verifyCertificate(key);

		}

		private function verifyCertificate(key:RSAKey):Boolean {

			var algo:String = getAlgorithmIdentifier();

			var hash:IHash;

			var oid:String;

			switch (algo) {

				case OID.SHA1_WITH_RSA_ENCRYPTION:

					hash = new SHA1;

					oid = OID.SHA1_ALGORITHM;

					break;

				case OID.MD2_WITH_RSA_ENCRYPTION:

					hash = new MD2;

					oid = OID.MD2_ALGORITHM;

					break;

				case OID.MD5_WITH_RSA_ENCRYPTION:

					hash = new MD5;

					oid = OID.MD5_ALGORITHM;

					break;

				default:

					return false;

			}

			var data:ByteArray = _obj.signedCertificate_bin;

			var buf:ByteArray = new ByteArray;

			key.verify(_obj.encrypted, buf, _obj.encrypted.length);

			buf.position=0;

			data = hash.hash(data);

			var obj:Object = DER.parse(buf, Type.RSA_SIGNATURE);

			if (obj.algorithm.algorithmId.toString() != oid) {

				return false; // wrong algorithm

			}

			if (!ArrayUtil.equals(obj.hash, data)) {

				return false; // hashes don't match

			}

			return true;

		}

		

		/**

		 * This isn't used anywhere so far.

		 * It would become useful if we started to offer facilities

		 * to generate and sign X509 certificates.

		 * 

		 * @param key

		 * @param algo

		 * @return 

		 * 

		 */

		private function signCertificate(key:RSAKey, algo:String):ByteArray {

			var hash:IHash;

			var oid:String;

			switch (algo) {

				case OID.SHA1_WITH_RSA_ENCRYPTION:

					hash = new SHA1;

					oid = OID.SHA1_ALGORITHM;

					break;

				case OID.MD2_WITH_RSA_ENCRYPTION:

					hash = new MD2;

					oid = OID.MD2_ALGORITHM;

					break;

				case OID.MD5_WITH_RSA_ENCRYPTION:

					hash = new MD5;

					oid = OID.MD5_ALGORITHM;

					break;

				default:

					return null

			}

			var data:ByteArray = _obj.signedCertificate_bin;

			data = hash.hash(data);

			var seq1:Sequence = new Sequence;

			seq1[0] = new Sequence;

			seq1[0][0] = new ObjectIdentifier(0,0, oid);

			seq1[0][1] = null;

			seq1[1] = new ByteString;

			seq1[1].writeBytes(data);

			data = seq1.toDER();

			var buf:ByteArray = new ByteArray;

			key.sign(data, buf, data.length);

			return buf;

		}

		

		public function getPublicKey():RSAKey {

			load();

			var pk:ByteArray = _obj.signedCertificate.subjectPublicKeyInfo.subjectPublicKey as ByteArray;

			pk.position = 0;

			var rsaKey:Object = DER.parse(pk, [{name:"N"},{name:"E"}]);

			return new RSAKey(rsaKey.N, rsaKey.E.valueOf());

		}

		

		/**

		 * Returns a subject principal, as an opaque base64 string.

		 * This is only used as a hash key for known certificates.

		 * 

		 * Note that this assumes X509 DER-encoded certificates are uniquely encoded,

		 * as we look for exact matches between Issuer and Subject fields.

		 * 

		 */

		public function getSubjectPrincipal():String {

			load();

			return Base64.encodeByteArray(_obj.signedCertificate.subject_bin);

		}

		/**

		 * Returns an issuer principal, as an opaque base64 string.

		 * This is only used to quickly find matching parent certificates.

		 * 

		 * Note that this assumes X509 DER-encoded certificates are uniquely encoded,

		 * as we look for exact matches between Issuer and Subject fields.

		 * 

		 */

		public function getIssuerPrincipal():String {

			load();

			return Base64.encodeByteArray(_obj.signedCertificate.issuer_bin);

		}

		public function getAlgorithmIdentifier():String {

			return _obj.algorithmIdentifier.algorithmId.toString();

		}

		public function getNotBefore():Date {

			return _obj.signedCertificate.validity.notBefore.date;

		}

		public function getNotAfter():Date {

			return _obj.signedCertificate.validity.notAfter.date;

		}

		

		public function getCommonName():String {

			var subject:Sequence = _obj.signedCertificate.subject;

			return (subject.findAttributeValue(OID.COMMON_NAME) as PrintableString).getString();

		}

	}

}