Fixed vulnerability CLP-01-016

3 files changed, 114 insertions, 37 deletions

diff --git a/frontend/beta/js/Clipperz/Crypto/SRP.js b/frontend/beta/js/Clipperz/Crypto/SRP.js
index 8cc80ba..8c522ad 100644
--- a/frontend/beta/js/Clipperz/Crypto/SRP.js
+++ b/frontend/beta/js/Clipperz/Crypto/SRP.js
@@ -1,326 +1,345 @@
 /*
 
 Copyright 2008-2013 Clipperz Srl
 
 This file is part of Clipperz, the online password manager.
 For further information about its features and functionalities please
 refer to http://www.clipperz.com.
 
 * Clipperz is free software: you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License, or 
   (at your option) any later version.
 
 * Clipperz is distributed in the hope that it will be useful, but 
   WITHOUT ANY WARRANTY; without even the implied warranty of 
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Affero General Public License for more details.
 
 * You should have received a copy of the GNU Affero General Public
   License along with Clipperz. If not, see http://www.gnu.org/licenses/.
 
 */
 
 try { if (typeof(Clipperz.ByteArray) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.PRNG depends on Clipperz.ByteArray!";
 }  
 
 try { if (typeof(Clipperz.Crypto.BigInt) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.BigInt!";
 }  
 
 try { if (typeof(Clipperz.Crypto.PRNG) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.PRNG!";
 }  
 
 if (typeof(Clipperz.Crypto.SRP) == 'undefined') { Clipperz.Crypto.SRP = {}; }
 
 Clipperz.Crypto.SRP.VERSION = "0.1";
 Clipperz.Crypto.SRP.NAME = "Clipperz.Crypto.SRP";
 
 //#############################################################################
 
 MochiKit.Base.update(Clipperz.Crypto.SRP, {
 
 	'_n': null,
 	'_g': null,
+	'_k': null,
+	
 	//-------------------------------------------------------------------------
 
 	'n': function() {
 		if (Clipperz.Crypto.SRP._n == null) {
 		 	Clipperz.Crypto.SRP._n = new Clipperz.Crypto.BigInt("115b8b692e0e045692cf280b436735c77a5a9e8a9e7ed56c965f87db5b2a2ece3", 16);
 		}
 		
 		return Clipperz.Crypto.SRP._n;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'g': function() {
 		if (Clipperz.Crypto.SRP._g == null) {
 			Clipperz.Crypto.SRP._g = new Clipperz.Crypto.BigInt(2);	//	eventually 5 (as suggested on the Diffi-Helmann documentation)
 		}
 		
 		return Clipperz.Crypto.SRP._g;
 	},
 
+	'k': function() {
+		if (Clipperz.Crypto.SRP._k == null) {
+//			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt(this.stringHash(this.n().asString() + this.g().asString()), 16);
+			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt("64398bff522814e306a97cb9bfc4364b7eed16a8c17c5208a40a2bad2933c8e", 16);
+		}
+		
+		return Clipperz.Crypto.SRP._k;
+	},
+	
 	//-----------------------------------------------------------------------------
 
 	'exception': {
 		'InvalidValue': new MochiKit.Base.NamedError("Clipperz.Crypto.SRP.exception.InvalidValue") 
 	},
 
 	//-------------------------------------------------------------------------
 	__syntaxFix__: "syntax fix"
 
 });
 
 //#############################################################################
 //
 //		S R P   C o n n e c t i o n     version 1.0
 //
 //=============================================================================
 Clipperz.Crypto.SRP.Connection = function (args) {
 	args = args || {};
 
 	this._C = args.C;
 	this._P = args.P;
 	this.hash = args.hash;
 
 	this._a = null;
 	this._A = null;
 	
 	this._s = null;
 	this._B = null;
 
 	this._x = null;
 	
 	this._u = null;
 	this._K = null;
 	this._M1 = null;
 	this._M2 = null;
 	
 	this._sessionKey = null;
 
 	return this;
 }
 
 Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
 	'toString': function () {
 		return "Clipperz.Crypto.SRP.Connection (username: " + this.username() + "). Status: " + this.statusDescription();
 	},
 
 	//-------------------------------------------------------------------------
 
 	'C': function () {
 		return this._C;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'P': function () {
 		return this._P;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'a': function () {
 		if (this._a == null) {
 			this._a = new Clipperz.Crypto.BigInt(Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2), 16);
 //			this._a = new Clipperz.Crypto.BigInt("37532428169486597638072888476611365392249575518156687476805936694442691012367", 10);
-//MochiKit.Logging.logDebug("SRP a: " + this._a);
 		}
 		
 		return this._a;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'A': function () {
 		if (this._A == null) {
-			//	Warning: this value should be strictly greater than zero: how should we perform this check?
+			//	Warning: this value should be strictly greater than zero
 			this._A = Clipperz.Crypto.SRP.g().powerModule(this.a(), Clipperz.Crypto.SRP.n());
-			
-			if (this._A.equals(0)) {
+			if (this._A.equals(0) || negative(this._A)) {
 MochiKit.Logging.logError("Clipperz.Crypto.SRP.Connection: trying to set 'A' to 0.");
 				throw Clipperz.Crypto.SRP.exception.InvalidValue;
 			}
-//MochiKit.Logging.logDebug("SRP A: " + this._A);
 		}
 		
 		return this._A;
 	},
 
 	//-------------------------------------------------------------------------
 
 	's': function () {
 		return this._s;
-//MochiKit.Logging.logDebug("SRP s: " + this._S);
 	},
 
 	'set_s': function(aValue) {
 		this._s = aValue;
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'B': function () {
 		return this._B;
 	},
 
 	'set_B': function(aValue) {
-		//	Warning: this value should be strictly greater than zero: how should we perform this check?
-		if (! aValue.equals(0)) {
+		//	Warning: this value should be strictly greater than zero
 			this._B = aValue;
-//MochiKit.Logging.logDebug("SRP B: " + this._B);
-		} else {
+		if (this._B.equals(0) || negative(this._B)) {
 MochiKit.Logging.logError("Clipperz.Crypto.SRP.Connection: trying to set 'B' to 0.");
 			throw Clipperz.Crypto.SRP.exception.InvalidValue;
 		}
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'x': function () {
 		if (this._x == null) {
 			this._x = new Clipperz.Crypto.BigInt(this.stringHash(this.s().asString(16, 64) + this.P()), 16);
-//MochiKit.Logging.logDebug("SRP x: " + this._x);
 		}
 		
 		return this._x;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'u': function () {
 		if (this._u == null) {
-			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.B().asString()), 16);
-//MochiKit.Logging.logDebug("SRP u: " + this._u);
+			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.A().asString() + this.B().asString()), 16);
 		}
 		
 		return this._u;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'S': function () {
 		if (this._S == null) {
 			var bigint;
 			var	srp;
 
 			bigint = Clipperz.Crypto.BigInt;
 			srp = 	 Clipperz.Crypto.SRP;
 
 			this._S =	bigint.powerModule(
-								bigint.subtract(this.B(), bigint.powerModule(srp.g(), this.x(), srp.n())),
+							bigint.subtract(
+								this.B(),
+								bigint.multiply(
+									Clipperz.Crypto.SRP.k(),
+									bigint.powerModule(srp.g(), this.x(), srp.n())
+								)
+							),
 								bigint.add(this.a(), bigint.multiply(this.u(), this.x())),
 								srp.n()
 						)
-//MochiKit.Logging.logDebug("SRP S: " + this._S);
 		}
 		
 		return this._S;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'K': function () {
 		if (this._K == null) {
 			this._K = this.stringHash(this.S().asString());
-//MochiKit.Logging.logDebug("SRP K: " + this._K);
 		}
 		
 		return this._K;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M1': function () {
 		if (this._M1 == null) {
-			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
-//MochiKit.Logging.logDebug("SRP M1: " + this._M1);
+//			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
+
+			//	http://srp.stanford.edu/design.html
+			//	User -> Host:  M = H(H(N) xor H(g), H(I), s, A, B, K)
+
+			this._M1 = this.stringHash(
+				"597626870978286801440197562148588907434001483655788865609375806439877501869636875571920406529" +
+				this.stringHash(this.C()) +
+				this.s().asString() +
+				this.A().asString() +
+				this.B().asString() +
+				this.K()
+			);
+//console.log("M1", this._M1);
 		}
 		
 		return this._M1;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M2': function () {
 		if (this._M2 == null) {
 			this._M2 = this.stringHash(this.A().asString(10) + this.M1() + this.K());
-//MochiKit.Logging.logDebug("SRP M2: " + this._M2);
+//console.log("M2", this._M2);
 		}
 		
 		return this._M2;
 	},
 
 	//=========================================================================
 
 	'serverSideCredentialsWithSalt': function(aSalt) {
 		var result;
 		var s, x, v;
 		
 		s = aSalt;
 		x = this.stringHash(s + this.P());
 		v = Clipperz.Crypto.SRP.g().powerModule(new Clipperz.Crypto.BigInt(x, 16), Clipperz.Crypto.SRP.n());
 
 		result = {};
 		result['C'] = this.C();
 		result['s'] = s;
 		result['v'] = v.asString(16);
 		
 		return result;
 	},
 	
 	'serverSideCredentials': function() {
 		var result;
 		var s;
 		
 		s = Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2);
 
 		result = this.serverSideCredentialsWithSalt(s);
 		
 		return result;
 	},
 	
 	//=========================================================================
 /*
 	'computeServerSide_S': function(b) {
 		var result;
 		var v;
 		var bigint;
 		var	srp;
 
 		bigint = Clipperz.Crypto.BigInt;
 		srp = 	 Clipperz.Crypto.SRP;
 
 		v = new Clipperz.Crypto.BigInt(srpConnection.serverSideCredentialsWithSalt(this.s().asString(16, 64)).v, 16);
 //		_S =  (this.A().multiply(this.v().modPow(this.u(), this.n()))).modPow(this.b(), this.n());
 		result = bigint.powerModule(
 					bigint.multiply(
 						this.A(),
 						bigint.powerModule(v, this.u(), srp.n())
 					), new Clipperz.Crypto.BigInt(b, 10), srp.n()
 				);
 
 		return result;
 	},
 */
 	//=========================================================================
 
 	'stringHash': function(aValue) {
 		var	result;
 
 		result = this.hash(new Clipperz.ByteArray(aValue)).toHexString().substring(2);
 		
 		return result;
 	},
 	
 	//=========================================================================
 	__syntaxFix__: "syntax fix"
 	
 });
 
 //#############################################################################
diff --git a/frontend/delta/js/Clipperz/Crypto/SRP.js b/frontend/delta/js/Clipperz/Crypto/SRP.js
index 597e72d..6898dfb 100644
--- a/frontend/delta/js/Clipperz/Crypto/SRP.js
+++ b/frontend/delta/js/Clipperz/Crypto/SRP.js
@@ -1,316 +1,345 @@
 /*
 
 Copyright 2008-2013 Clipperz Srl
 
 This file is part of Clipperz, the online password manager.
 For further information about its features and functionalities please
 refer to http://www.clipperz.com.
 
 * Clipperz is free software: you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License, or 
   (at your option) any later version.
 
 * Clipperz is distributed in the hope that it will be useful, but 
   WITHOUT ANY WARRANTY; without even the implied warranty of 
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Affero General Public License for more details.
 
 * You should have received a copy of the GNU Affero General Public
   License along with Clipperz. If not, see http://www.gnu.org/licenses/.
 
 */
 
 try { if (typeof(Clipperz.ByteArray) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.PRNG depends on Clipperz.ByteArray!";
 }  
 
 try { if (typeof(Clipperz.Crypto.BigInt) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.BigInt!";
 }  
 
 try { if (typeof(Clipperz.Crypto.PRNG) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.PRNG!";
 }  
 
 if (typeof(Clipperz.Crypto.SRP) == 'undefined') { Clipperz.Crypto.SRP = {}; }
 
 Clipperz.Crypto.SRP.VERSION = "0.1";
 Clipperz.Crypto.SRP.NAME = "Clipperz.Crypto.SRP";
 
 //#############################################################################
 
 MochiKit.Base.update(Clipperz.Crypto.SRP, {
 
 	'_n': null,
 	'_g': null,
+	'_k': null,
+	
 	//-------------------------------------------------------------------------
 
 	'n': function() {
 		if (Clipperz.Crypto.SRP._n == null) {
 		 	Clipperz.Crypto.SRP._n = new Clipperz.Crypto.BigInt("115b8b692e0e045692cf280b436735c77a5a9e8a9e7ed56c965f87db5b2a2ece3", 16);
 		}
 		
 		return Clipperz.Crypto.SRP._n;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'g': function() {
 		if (Clipperz.Crypto.SRP._g == null) {
 			Clipperz.Crypto.SRP._g = new Clipperz.Crypto.BigInt(2);	//	eventually 5 (as suggested on the Diffi-Helmann documentation)
 		}
 		
 		return Clipperz.Crypto.SRP._g;
 	},
 
+	'k': function() {
+		if (Clipperz.Crypto.SRP._k == null) {
+//			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt(this.stringHash(this.n().asString() + this.g().asString()), 16);
+			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt("64398bff522814e306a97cb9bfc4364b7eed16a8c17c5208a40a2bad2933c8e", 16);
+		}
+		
+		return Clipperz.Crypto.SRP._k;
+	},
+	
 	//-----------------------------------------------------------------------------
 
 	'exception': {
 		'InvalidValue': new MochiKit.Base.NamedError("Clipperz.Crypto.SRP.exception.InvalidValue") 
 	},
 
 	//-------------------------------------------------------------------------
 	__syntaxFix__: "syntax fix"
 
 });
 
 //#############################################################################
 //
 //		S R P   C o n n e c t i o n     version 1.0
 //
 //=============================================================================
 Clipperz.Crypto.SRP.Connection = function (args) {
 	args = args || {};
 
 	this._C = args.C;
 	this._P = args.P;
 	this.hash = args.hash;
 
 	this._a = null;
 	this._A = null;
 	
 	this._s = null;
 	this._B = null;
 
 	this._x = null;
 	
 	this._u = null;
 	this._K = null;
 	this._M1 = null;
 	this._M2 = null;
 	
 	this._sessionKey = null;
 
 	return this;
 }
 
 Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
 	'toString': function () {
 		return "Clipperz.Crypto.SRP.Connection (username: " + this.username() + "). Status: " + this.statusDescription();
 	},
 
 	//-------------------------------------------------------------------------
 
 	'C': function () {
 		return this._C;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'P': function () {
 		return this._P;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'a': function () {
 		if (this._a == null) {
 			this._a = new Clipperz.Crypto.BigInt(Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2), 16);
 //			this._a = new Clipperz.Crypto.BigInt("37532428169486597638072888476611365392249575518156687476805936694442691012367", 10);
 		}
 		
 		return this._a;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'A': function () {
 		if (this._A == null) {
-			//	Warning: this value should be strictly greater than zero: how should we perform this check?
+			//	Warning: this value should be strictly greater than zero
 			this._A = Clipperz.Crypto.SRP.g().powerModule(this.a(), Clipperz.Crypto.SRP.n());
-			
-			if (this._A.equals(0)) {
+			if (this._A.equals(0) || negative(this._A)) {
 				Clipperz.logError("Clipperz.Crypto.SRP.Connection: trying to set 'A' to 0.");
 				throw Clipperz.Crypto.SRP.exception.InvalidValue;
 			}
 		}
 		
 		return this._A;
 	},
 
 	//-------------------------------------------------------------------------
 
 	's': function () {
 		return this._s;
 	},
 
 	'set_s': function(aValue) {
 		this._s = aValue;
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'B': function () {
 		return this._B;
 	},
 
 	'set_B': function(aValue) {
-		//	Warning: this value should be strictly greater than zero: how should we perform this check?
-		if (! aValue.equals(0)) {
+		//	Warning: this value should be strictly greater than zero
 			this._B = aValue;
-		} else {
+		if (this._B.equals(0) || negative(this._B)) {
 			Clipperz.logError("Clipperz.Crypto.SRP.Connection: trying to set 'B' to 0.");
 			throw Clipperz.Crypto.SRP.exception.InvalidValue;
 		}
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'x': function () {
 		if (this._x == null) {
 			this._x = new Clipperz.Crypto.BigInt(this.stringHash(this.s().asString(16, 64) + this.P()), 16);
 		}
 		
 		return this._x;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'u': function () {
 		if (this._u == null) {
-			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.B().asString()), 16);
+			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.A().asString() + this.B().asString()), 16);
 		}
 		
 		return this._u;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'S': function () {
 		if (this._S == null) {
 			var bigint;
 			var	srp;
 
 			bigint = Clipperz.Crypto.BigInt;
 			srp = 	 Clipperz.Crypto.SRP;
 
 			this._S =	bigint.powerModule(
-								bigint.subtract(this.B(), bigint.powerModule(srp.g(), this.x(), srp.n())),
+							bigint.subtract(
+								this.B(),
+								bigint.multiply(
+									Clipperz.Crypto.SRP.k(),
+									bigint.powerModule(srp.g(), this.x(), srp.n())
+								)
+							),
 								bigint.add(this.a(), bigint.multiply(this.u(), this.x())),
 								srp.n()
 						)
 		}
 		
 		return this._S;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'K': function () {
 		if (this._K == null) {
 			this._K = this.stringHash(this.S().asString());
 		}
 		
 		return this._K;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M1': function () {
 		if (this._M1 == null) {
-			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
+//			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
+
+			//	http://srp.stanford.edu/design.html
+			//	User -> Host:  M = H(H(N) xor H(g), H(I), s, A, B, K)
+
+			this._M1 = this.stringHash(
+				"597626870978286801440197562148588907434001483655788865609375806439877501869636875571920406529" +
+				this.stringHash(this.C()) +
+				this.s().asString() +
+				this.A().asString() +
+				this.B().asString() +
+				this.K()
+			);
+//console.log("M1", this._M1);
 		}
 		
 		return this._M1;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M2': function () {
 		if (this._M2 == null) {
 			this._M2 = this.stringHash(this.A().asString(10) + this.M1() + this.K());
+//console.log("M2", this._M2);
 		}
 		
 		return this._M2;
 	},
 
 	//=========================================================================
 
 	'serverSideCredentialsWithSalt': function(aSalt) {
 		var result;
 		var s, x, v;
 		
 		s = aSalt;
 		x = this.stringHash(s + this.P());
 		v = Clipperz.Crypto.SRP.g().powerModule(new Clipperz.Crypto.BigInt(x, 16), Clipperz.Crypto.SRP.n());
 
 		result = {};
 		result['C'] = this.C();
 		result['s'] = s;
 		result['v'] = v.asString(16);
 		
 		return result;
 	},
 	
 	'serverSideCredentials': function() {
 		var result;
 		var s;
 		
 		s = Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2);
 
 		result = this.serverSideCredentialsWithSalt(s);
 		
 		return result;
 	},
 	
 	//=========================================================================
 /*
 	'computeServerSide_S': function(b) {
 		var result;
 		var v;
 		var bigint;
 		var	srp;
 
 		bigint = Clipperz.Crypto.BigInt;
 		srp = 	 Clipperz.Crypto.SRP;
 
 		v = new Clipperz.Crypto.BigInt(srpConnection.serverSideCredentialsWithSalt(this.s().asString(16, 64)).v, 16);
 //		_S =  (this.A().multiply(this.v().modPow(this.u(), this.n()))).modPow(this.b(), this.n());
 		result = bigint.powerModule(
 					bigint.multiply(
 						this.A(),
 						bigint.powerModule(v, this.u(), srp.n())
 					), new Clipperz.Crypto.BigInt(b, 10), srp.n()
 				);
 
 		return result;
 	},
 */
 	//=========================================================================
 
 	'stringHash': function(aValue) {
 		var	result;
 
 		result = this.hash(new Clipperz.ByteArray(aValue)).toHexString().substring(2);
 		
 		return result;
 	},
 	
 	//=========================================================================
 	__syntaxFix__: "syntax fix"
 	
 });
 
 //#############################################################################
diff --git a/frontend/gamma/js/Clipperz/Crypto/SRP.js b/frontend/gamma/js/Clipperz/Crypto/SRP.js
index 597e72d..6898dfb 100644
--- a/frontend/gamma/js/Clipperz/Crypto/SRP.js
+++ b/frontend/gamma/js/Clipperz/Crypto/SRP.js
@@ -1,316 +1,345 @@
 /*
 
 Copyright 2008-2013 Clipperz Srl
 
 This file is part of Clipperz, the online password manager.
 For further information about its features and functionalities please
 refer to http://www.clipperz.com.
 
 * Clipperz is free software: you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License, or 
   (at your option) any later version.
 
 * Clipperz is distributed in the hope that it will be useful, but 
   WITHOUT ANY WARRANTY; without even the implied warranty of 
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   See the GNU Affero General Public License for more details.
 
 * You should have received a copy of the GNU Affero General Public
   License along with Clipperz. If not, see http://www.gnu.org/licenses/.
 
 */
 
 try { if (typeof(Clipperz.ByteArray) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.PRNG depends on Clipperz.ByteArray!";
 }  
 
 try { if (typeof(Clipperz.Crypto.BigInt) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.BigInt!";
 }  
 
 try { if (typeof(Clipperz.Crypto.PRNG) == 'undefined') { throw ""; }} catch (e) {
 	throw "Clipperz.Crypto.SRP depends on Clipperz.Crypto.PRNG!";
 }  
 
 if (typeof(Clipperz.Crypto.SRP) == 'undefined') { Clipperz.Crypto.SRP = {}; }
 
 Clipperz.Crypto.SRP.VERSION = "0.1";
 Clipperz.Crypto.SRP.NAME = "Clipperz.Crypto.SRP";
 
 //#############################################################################
 
 MochiKit.Base.update(Clipperz.Crypto.SRP, {
 
 	'_n': null,
 	'_g': null,
+	'_k': null,
+	
 	//-------------------------------------------------------------------------
 
 	'n': function() {
 		if (Clipperz.Crypto.SRP._n == null) {
 		 	Clipperz.Crypto.SRP._n = new Clipperz.Crypto.BigInt("115b8b692e0e045692cf280b436735c77a5a9e8a9e7ed56c965f87db5b2a2ece3", 16);
 		}
 		
 		return Clipperz.Crypto.SRP._n;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'g': function() {
 		if (Clipperz.Crypto.SRP._g == null) {
 			Clipperz.Crypto.SRP._g = new Clipperz.Crypto.BigInt(2);	//	eventually 5 (as suggested on the Diffi-Helmann documentation)
 		}
 		
 		return Clipperz.Crypto.SRP._g;
 	},
 
+	'k': function() {
+		if (Clipperz.Crypto.SRP._k == null) {
+//			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt(this.stringHash(this.n().asString() + this.g().asString()), 16);
+			Clipperz.Crypto.SRP._k = new Clipperz.Crypto.BigInt("64398bff522814e306a97cb9bfc4364b7eed16a8c17c5208a40a2bad2933c8e", 16);
+		}
+		
+		return Clipperz.Crypto.SRP._k;
+	},
+	
 	//-----------------------------------------------------------------------------
 
 	'exception': {
 		'InvalidValue': new MochiKit.Base.NamedError("Clipperz.Crypto.SRP.exception.InvalidValue") 
 	},
 
 	//-------------------------------------------------------------------------
 	__syntaxFix__: "syntax fix"
 
 });
 
 //#############################################################################
 //
 //		S R P   C o n n e c t i o n     version 1.0
 //
 //=============================================================================
 Clipperz.Crypto.SRP.Connection = function (args) {
 	args = args || {};
 
 	this._C = args.C;
 	this._P = args.P;
 	this.hash = args.hash;
 
 	this._a = null;
 	this._A = null;
 	
 	this._s = null;
 	this._B = null;
 
 	this._x = null;
 	
 	this._u = null;
 	this._K = null;
 	this._M1 = null;
 	this._M2 = null;
 	
 	this._sessionKey = null;
 
 	return this;
 }
 
 Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
 	'toString': function () {
 		return "Clipperz.Crypto.SRP.Connection (username: " + this.username() + "). Status: " + this.statusDescription();
 	},
 
 	//-------------------------------------------------------------------------
 
 	'C': function () {
 		return this._C;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'P': function () {
 		return this._P;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'a': function () {
 		if (this._a == null) {
 			this._a = new Clipperz.Crypto.BigInt(Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2), 16);
 //			this._a = new Clipperz.Crypto.BigInt("37532428169486597638072888476611365392249575518156687476805936694442691012367", 10);
 		}
 		
 		return this._a;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'A': function () {
 		if (this._A == null) {
-			//	Warning: this value should be strictly greater than zero: how should we perform this check?
+			//	Warning: this value should be strictly greater than zero
 			this._A = Clipperz.Crypto.SRP.g().powerModule(this.a(), Clipperz.Crypto.SRP.n());
-			
-			if (this._A.equals(0)) {
+			if (this._A.equals(0) || negative(this._A)) {
 				Clipperz.logError("Clipperz.Crypto.SRP.Connection: trying to set 'A' to 0.");
 				throw Clipperz.Crypto.SRP.exception.InvalidValue;
 			}
 		}
 		
 		return this._A;
 	},
 
 	//-------------------------------------------------------------------------
 
 	's': function () {
 		return this._s;
 	},
 
 	'set_s': function(aValue) {
 		this._s = aValue;
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'B': function () {
 		return this._B;
 	},
 
 	'set_B': function(aValue) {
-		//	Warning: this value should be strictly greater than zero: how should we perform this check?
-		if (! aValue.equals(0)) {
+		//	Warning: this value should be strictly greater than zero
 			this._B = aValue;
-		} else {
+		if (this._B.equals(0) || negative(this._B)) {
 			Clipperz.logError("Clipperz.Crypto.SRP.Connection: trying to set 'B' to 0.");
 			throw Clipperz.Crypto.SRP.exception.InvalidValue;
 		}
 	},
 	
 	//-------------------------------------------------------------------------
 
 	'x': function () {
 		if (this._x == null) {
 			this._x = new Clipperz.Crypto.BigInt(this.stringHash(this.s().asString(16, 64) + this.P()), 16);
 		}
 		
 		return this._x;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'u': function () {
 		if (this._u == null) {
-			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.B().asString()), 16);
+			this._u = new Clipperz.Crypto.BigInt(this.stringHash(this.A().asString() + this.B().asString()), 16);
 		}
 		
 		return this._u;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'S': function () {
 		if (this._S == null) {
 			var bigint;
 			var	srp;
 
 			bigint = Clipperz.Crypto.BigInt;
 			srp = 	 Clipperz.Crypto.SRP;
 
 			this._S =	bigint.powerModule(
-								bigint.subtract(this.B(), bigint.powerModule(srp.g(), this.x(), srp.n())),
+							bigint.subtract(
+								this.B(),
+								bigint.multiply(
+									Clipperz.Crypto.SRP.k(),
+									bigint.powerModule(srp.g(), this.x(), srp.n())
+								)
+							),
 								bigint.add(this.a(), bigint.multiply(this.u(), this.x())),
 								srp.n()
 						)
 		}
 		
 		return this._S;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'K': function () {
 		if (this._K == null) {
 			this._K = this.stringHash(this.S().asString());
 		}
 		
 		return this._K;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M1': function () {
 		if (this._M1 == null) {
-			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
+//			this._M1 = this.stringHash(this.A().asString(10) + this.B().asString(10) + this.K());
+
+			//	http://srp.stanford.edu/design.html
+			//	User -> Host:  M = H(H(N) xor H(g), H(I), s, A, B, K)
+
+			this._M1 = this.stringHash(
+				"597626870978286801440197562148588907434001483655788865609375806439877501869636875571920406529" +
+				this.stringHash(this.C()) +
+				this.s().asString() +
+				this.A().asString() +
+				this.B().asString() +
+				this.K()
+			);
+//console.log("M1", this._M1);
 		}
 		
 		return this._M1;
 	},
 
 	//-------------------------------------------------------------------------
 
 	'M2': function () {
 		if (this._M2 == null) {
 			this._M2 = this.stringHash(this.A().asString(10) + this.M1() + this.K());
+//console.log("M2", this._M2);
 		}
 		
 		return this._M2;
 	},
 
 	//=========================================================================
 
 	'serverSideCredentialsWithSalt': function(aSalt) {
 		var result;
 		var s, x, v;
 		
 		s = aSalt;
 		x = this.stringHash(s + this.P());
 		v = Clipperz.Crypto.SRP.g().powerModule(new Clipperz.Crypto.BigInt(x, 16), Clipperz.Crypto.SRP.n());
 
 		result = {};
 		result['C'] = this.C();
 		result['s'] = s;
 		result['v'] = v.asString(16);
 		
 		return result;
 	},
 	
 	'serverSideCredentials': function() {
 		var result;
 		var s;
 		
 		s = Clipperz.Crypto.PRNG.defaultRandomGenerator().getRandomBytes(32).toHexString().substring(2);
 
 		result = this.serverSideCredentialsWithSalt(s);
 		
 		return result;
 	},
 	
 	//=========================================================================
 /*
 	'computeServerSide_S': function(b) {
 		var result;
 		var v;
 		var bigint;
 		var	srp;
 
 		bigint = Clipperz.Crypto.BigInt;
 		srp = 	 Clipperz.Crypto.SRP;
 
 		v = new Clipperz.Crypto.BigInt(srpConnection.serverSideCredentialsWithSalt(this.s().asString(16, 64)).v, 16);
 //		_S =  (this.A().multiply(this.v().modPow(this.u(), this.n()))).modPow(this.b(), this.n());
 		result = bigint.powerModule(
 					bigint.multiply(
 						this.A(),
 						bigint.powerModule(v, this.u(), srp.n())
 					), new Clipperz.Crypto.BigInt(b, 10), srp.n()
 				);
 
 		return result;
 	},
 */
 	//=========================================================================
 
 	'stringHash': function(aValue) {
 		var	result;
 
 		result = this.hash(new Clipperz.ByteArray(aValue)).toHexString().substring(2);
 		
 		return result;
 	},
 	
 	//=========================================================================
 	__syntaxFix__: "syntax fix"
 	
 });
 
 //#############################################################################