1 files changed, 122 insertions, 0 deletions
diff --git a/app/assets/javascripts/srp/src/srp_session.js b/app/assets/javascripts/srp/src/srp_session.js
new file mode 100644
index 0000000..88f19d5
--- /dev/null
+++ b/app/assets/javascripts/srp/src/srp_session.js
@@ -0,0 +1,122 @@
+srp.Session = function(account, calculate) {
+
+  // default for injected dependency
+  account = account || new srp.Account();
+  calculate = calculate || new srp.Calculate();
+
+  var a = calculate.randomEphemeral();
+  var A = calculate.A(a);
+  var S = null;
+  var K = null;
+  var M = null;
+  var M2 = null;
+  var authenticated = false;
+
+  // *** Accessor methods ***
+
+  // allows setting the random number A for testing
+
+  this.calculateAndSetA = function(_a) {
+    a = _a;
+    A = calculate.A(_a);
+    return A;
+  };
+
+  this.update = function() {
+    var salt = calculate.randomSalt();
+    var x = calculate.X(account.login(), account.password(), salt);
+    return {
+      login: account.login(),
+      password_salt: salt,
+      password_verifier: calculate.V(x)
+    };
+  }
+
+  this.signup = function() {
+    var loginParams = this.update();
+
+    if (account.loginParams) {
+      var extraParams = account.loginParams();
+      for (var attr in extraParams) {
+        loginParams[attr] = extraParams[attr];
+      }
+    }
+
+    return loginParams;
+  };
+
+  this.handshake = function() {
+    return {
+      login: account.login(),
+      A: this.getA()
+    };
+  };
+
+  this.getA = function() {
+    return A;
+  }
+
+  // Delegate login & id so they can be used when talking to the remote
+  this.login = account.login;
+  this.id = account.id;
+
+  // Calculate S, M, and M2
+  // This is the client side of the SRP specification
+  this.calculations = function(salt, ephemeral)
+  {
+    //S -> C: s | B
+    var B = calculate.zeroPrefix(ephemeral);
+    salt = calculate.zeroPrefix(salt);
+    var x = calculate.X(account.login(), account.password(), salt);
+    S = calculate.S(a, A, B, x);
+    K = calculate.K(S);
+
+    // M = H(H(N) xor H(g), H(I), s, A, B, K)
+    var xor = calculate.nXorG();
+    var hash_i = calculate.hash(account.login())
+    M = calculate.hashHex(xor + hash_i + salt + A + B + K);
+    //M2 = H(A, M, K)
+    M2 = calculate.hashHex(A + M + K);
+  };
+
+
+  this.getS = function() {
+    return S;
+  }
+
+  this.getM = function() {
+    return M;
+  }
+
+  this.validate = function(serverM2) {
+    authenticated = (serverM2 && serverM2 == M2)
+    return authenticated;
+  }
+
+  // If someone wants to use the session key for encrypting traffic, they can
+  // access the key with this function.
+  this.key = function()
+  {
+    if(K) {
+      return K;
+    } else {
+      this.onError("User has not been authenticated.");
+    }
+  };
+
+  // Encrypt plaintext using slowAES
+  this.encrypt = function(plaintext)
+  {
+    var key = cryptoHelpers.toNumbers(session.key());
+    var byteMessage = cryptoHelpers.convertStringToByteArray(plaintext);
+    var iv = new Array(16);
+    rng.nextBytes(iv);
+    var paddedByteMessage = slowAES.getPaddedBlock(byteMessage, 0, byteMessage.length, slowAES.modeOfOperation.CFB);
+    var ciphertext = slowAES.encrypt(paddedByteMessage, slowAES.modeOfOperation.CFB, key, key.length, iv).cipher;
+    var retstring = cryptoHelpers.base64.encode(iv.concat(ciphertext));
+    while(retstring.indexOf("+",0) > -1)
+      retstring = retstring.replace("+", "_");
+    return retstring;
+  };
+};
+