prefix incoming B too

2 files changed, 5 insertions, 2 deletions

diff --git a/src/srp_calculate.js b/src/srp_calculate.js
index 9196e0c..a1cbe51 100644
--- a/src/srp_calculate.js
+++ b/src/srp_calculate.js
@@ -73,10 +73,13 @@ srp.Calculate = function() {
   
   // some 16 byte random number
   this.randomSalt = function() {
-    salt = new BigInteger(64, rng);
+    var salt = new BigInteger(64, rng);
     return zeroPrefix(salt.toString(16));
   }
 
+  // expose zeroPrefix for received values.
+  this.zeroPrefix = zeroPrefix;
+
   function hex2a(hex) {
     var str = '';
     if(hex.length % 2) {
diff --git a/src/srp_session.js b/src/srp_session.js
index 0648959..0b0e4c6 100644
--- a/src/srp_session.js
+++ b/src/srp_session.js
@@ -52,7 +52,7 @@ srp.Session = function(account, calculate) {
   this.calculations = function(salt, ephemeral)
   {
     //S -> C: s | B
-    var B = ephemeral;
+    var B = calculate.zeroPrefix(ephemeral);
     var x = calculate.X(account.login(), account.password(), salt);
     S = calculate.S(a, A, B, x);
     K = calculate.K(S);