Fixed vulnerability CLP-01-016

1 files changed, 41 insertions, 12 deletions

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
@@ -44,6 +44,8 @@ MochiKit.Base.update(Clipperz.Crypto.SRP, {
 
         '_n': null,
         '_g': null,
+        '_k': null,
+        
         //-------------------------------------------------------------------------
 
         'n': function() {
@@ -64,6 +66,15 @@ MochiKit.Base.update(Clipperz.Crypto.SRP, {
                 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': {
@@ -138,10 +149,9 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
         '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;
                         }
@@ -167,10 +177,9 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
         },
 
         'set_B': function(aValue) {
-                        //Warning: this value should be strictly greater than zero: how should we perform this check?
-                if (! aValue.equals(0)) {
-                        this._B = aValue;
-                } else {
+                        //Warning: this value should be strictly greater than zero
+                this._B = aValue;
+                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;
                 }
@@ -190,7 +199,7 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
         '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;
@@ -207,9 +216,15 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
                                 srp =  Clipperz.Crypto.SRP;
 
                                 this._S =bigint.powerModule(
-                                                                bigint.subtract(this.B(), bigint.powerModule(srp.g(), this.x(), srp.n())),
-                                                                bigint.add(this.a(), bigint.multiply(this.u(), 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()
                                                 )
                 }
                 
@@ -230,7 +245,20 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
 
         '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;
@@ -241,6 +269,7 @@ Clipperz.Crypto.SRP.Connection.prototype = MochiKit.Base.update(null, {
         '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;