diff --git a/contrib/securityLib/sha256.js b/contrib/securityLib/sha256.js
new file mode 100644
index 0000000..51016cf
--- /dev/null
+++ b/contrib/securityLib/sha256.js
@@ -0,0 +1,475 @@
+/*
+ * A JavaScript implementation of the Secure Hash Algorithm, SHA-256, as defined
+ * in FIPS 180-2
+ * Version 2.2 Copyright Angel Marin, Paul Johnston 2000 - 2009.
+ * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
+ * Distributed under the BSD License
+ * See http://pajhome.org.uk/crypt/md5 for details.
+ * Also http://anmar.eu.org/projects/jssha2/
+ */
+
+/*
+ * Configurable variables. You may need to tweak these to be compatible with
+ * the server-side, but the defaults work in most cases.
+ */
+var hexcase = 0;  /* hex output format. 0 - lowercase; 1 - uppercase        */
+var b64pad  = ""; /* base-64 pad character. "=" for strict RFC compliance   */
+
+/*
+ * These are the functions you'll usually want to call
+ * They take string arguments and return either hex or base-64 encoded strings
+ */
+
+//@author axelcdv
+/**
+ * Computes the Sha-256 hash of the given byte array
+ * @param {byte[]} 
+ * @return the hex string corresponding to the Sha-256 hash of the byte array
+ */
+function hex_sha256_from_bytes(byteArray){
+	return rstr2hex(binb2rstr(binb_sha256( byteArray2binb(byteArray), byteArray.length * 8)));
+}
+
+function hex_sha256(s)    { return rstr2hex(rstr_sha256(str2rstr_utf8(s))); }
+function b64_sha256(s)    { return rstr2b64(rstr_sha256(str2rstr_utf8(s))); }
+function any_sha256(s, e) { return rstr2any(rstr_sha256(str2rstr_utf8(s)), e); }
+function hex_hmac_sha256(k, d)
+  { return rstr2hex(rstr_hmac_sha256(str2rstr_utf8(k), str2rstr_utf8(d))); }
+function b64_hmac_sha256(k, d)
+  { return rstr2b64(rstr_hmac_sha256(str2rstr_utf8(k), str2rstr_utf8(d))); }
+function any_hmac_sha256(k, d, e)
+  { return rstr2any(rstr_hmac_sha256(str2rstr_utf8(k), str2rstr_utf8(d)), e); }
+
+	
+/*
+	function hex_sha256(s)    { return rstr2hex(rstr_sha256(s)); }
+function b64_sha256(s)    { return rstr2b64(rstr_sha256(s)); }
+function any_sha256(s, e) { return rstr2any(rstr_sha256(s), e); }
+function hex_hmac_sha256(k, d)
+  { return rstr2hex(rstr_hmac_sha256(str2rstr_utf8(k), d)); }
+function b64_hmac_sha256(k, d)
+  { return rstr2b64(rstr_hmac_sha256(str2rstr_utf8(k), d)); }
+function any_hmac_sha256(k, d, e)
+  { return rstr2any(rstr_hmac_sha256(str2rstr_utf8(k), d), e); }
+*/
+	
+/*
+ * Perform a simple self-test to see if the VM is working
+ */
+function sha256_vm_test()
+{
+  return hex_sha256("abc").toLowerCase() ==
+            "ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad";
+}
+
+/**
+ * Calculate the sha256 of a raw string
+ * @param s: the raw string
+ */
+function rstr_sha256(s)
+{
+  return binb2rstr(binb_sha256(rstr2binb(s), s.length * 8));
+}
+
+/**
+ * Calculate the HMAC-sha256 of a key and some data (raw strings)
+ */
+function rstr_hmac_sha256(key, data)
+{
+  var bkey = rstr2binb(key);
+  if(bkey.length > 16) bkey = binb_sha256(bkey, key.length * 8);
+
+  var ipad = Array(16), opad = Array(16);
+  for(var i = 0; i < 16; i++)
+  {
+    ipad[i] = bkey[i] ^ 0x36363636;
+    opad[i] = bkey[i] ^ 0x5C5C5C5C;
+  }
+
+  var hash = binb_sha256(ipad.concat(rstr2binb(data)), 512 + data.length * 8);
+  return binb2rstr(binb_sha256(opad.concat(hash), 512 + 256));
+}
+
+/**
+ * Convert a raw string to a hex string
+ */
+function rstr2hex(input)
+{
+  try { hexcase } catch(e) { hexcase=0; }
+  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
+  var output = "";
+  var x;
+  for(var i = 0; i < input.length; i++)
+  {
+    x = input.charCodeAt(i);
+    output += hex_tab.charAt((x >>> 4) & 0x0F)
+           +  hex_tab.charAt( x        & 0x0F);
+  }
+  return output;
+}
+
+/*
+ * Convert a raw string to a base-64 string
+ */
+function rstr2b64(input)
+{
+  try { b64pad } catch(e) { b64pad=''; }
+  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+  var output = "";
+  var len = input.length;
+  for(var i = 0; i < len; i += 3)
+  {
+    var triplet = (input.charCodeAt(i) << 16)
+                | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
+                | (i + 2 < len ? input.charCodeAt(i+2)      : 0);
+    for(var j = 0; j < 4; j++)
+    {
+      if(i * 8 + j * 6 > input.length * 8) output += b64pad;
+      else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
+    }
+  }
+  return output;
+}
+
+/*
+ * Convert a raw string to an arbitrary string encoding
+ */
+function rstr2any(input, encoding)
+{
+  var divisor = encoding.length;
+  var remainders = Array();
+  var i, q, x, quotient;
+
+  /* Convert to an array of 16-bit big-endian values, forming the dividend */
+  var dividend = Array(Math.ceil(input.length / 2));
+  for(i = 0; i < dividend.length; i++)
+  {
+    dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
+  }
+
+  /*
+   * Repeatedly perform a long division. The binary array forms the dividend,
+   * the length of the encoding is the divisor. Once computed, the quotient
+   * forms the dividend for the next step. We stop when the dividend is zero.
+   * All remainders are stored for later use.
+   */
+  while(dividend.length > 0)
+  {
+    quotient = Array();
+    x = 0;
+    for(i = 0; i < dividend.length; i++)
+    {
+      x = (x << 16) + dividend[i];
+      q = Math.floor(x / divisor);
+      x -= q * divisor;
+      if(quotient.length > 0 || q > 0)
+        quotient[quotient.length] = q;
+    }
+    remainders[remainders.length] = x;
+    dividend = quotient;
+  }
+
+  /* Convert the remainders to the output string */
+  var output = "";
+  for(i = remainders.length - 1; i >= 0; i--)
+    output += encoding.charAt(remainders[i]);
+
+  /* Append leading zero equivalents */
+  var full_length = Math.ceil(input.length * 8 /
+                                    (Math.log(encoding.length) / Math.log(2)))
+  for(i = output.length; i < full_length; i++)
+    output = encoding[0] + output;
+
+  return output;
+}
+
+/*
+ * Encode a string as utf-8.
+ * For efficiency, this assumes the input is valid utf-16.
+ */
+function str2rstr_utf8(input)
+{
+  var output = "";
+  var i = -1;
+  var x, y;
+
+  while(++i < input.length)
+  {
+    /* Decode utf-16 surrogate pairs */
+    x = input.charCodeAt(i);
+    y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
+    if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF)
+    {
+      x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
+      i++;
+    }
+
+    /* Encode output as utf-8 */
+    if(x <= 0x7F)
+      output += String.fromCharCode(x);
+    else if(x <= 0x7FF)
+      output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),
+                                    0x80 | ( x         & 0x3F));
+    else if(x <= 0xFFFF)
+      output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
+                                    0x80 | ((x >>> 6 ) & 0x3F),
+                                    0x80 | ( x         & 0x3F));
+    else if(x <= 0x1FFFFF)
+      output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
+                                    0x80 | ((x >>> 12) & 0x3F),
+                                    0x80 | ((x >>> 6 ) & 0x3F),
+                                    0x80 | ( x         & 0x3F));
+  }
+  return output;
+}
+
+/*
+ * Encode a string as utf-16
+ */
+function str2rstr_utf16le(input)
+{
+  var output = "";
+  for(var i = 0; i < input.length; i++)
+    output += String.fromCharCode( input.charCodeAt(i)        & 0xFF,
+                                  (input.charCodeAt(i) >>> 8) & 0xFF);
+  return output;
+}
+
+function str2rstr_utf16be(input)
+{
+  var output = "";
+  for(var i = 0; i < input.length; i++)
+    output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,
+                                   input.charCodeAt(i)        & 0xFF);
+  return output;
+}
+
+/**
+ * Convert a raw string to an array of big-endian words
+ * Characters >255 have their high-byte silently ignored.
+ */
+function rstr2binb(input)
+{
+  //console.log('Raw string comming is '+input);
+  var output = Array(input.length >> 2);
+  /* JavaScript automatically zeroizes a new array.
+  for(var i = 0; i < output.length; i++)
+    output[i] = 0;
+   */
+  for(var i = 0; i < input.length * 8; i += 8)
+    output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32);
+  return output;
+}
+
+/**
+ * @author axelcdv
+ * Convert a byte array to an array of big-endian words
+ * @param {byte[]} input
+ * @return the array of big-endian words
+ */
+function byteArray2binb(input){
+	//console.log("Byte array coming is " + input);
+	var output = Array(input.length >> 2);
+      /* JavaScript automatically zeroizes a new array.
+	  for(var i = 0; i < output.length; i++)
+	    output[i] = 0;
+       */
+	  for(var i = 0; i < input.length * 8; i += 8)
+	    output[i>>5] |= (input[i / 8] & 0xFF) << (24 - i % 32);
+	  return output;
+}
+
+/*
+ * Convert an array of big-endian words to a string
+ */
+function binb2rstr(input)
+{
+  var output = "";
+  for(var i = 0; i < input.length * 32; i += 8)
+    output += String.fromCharCode((input[i>>5] >>> (24 - i % 32)) & 0xFF);
+  return output;
+}
+
+/*
+ * Main sha256 function, with its support functions
+ */
+function sha256_S (X, n) {return ( X >>> n ) | (X << (32 - n));}
+function sha256_R (X, n) {return ( X >>> n );}
+function sha256_Ch(x, y, z) {return ((x & y) ^ ((~x) & z));}
+function sha256_Maj(x, y, z) {return ((x & y) ^ (x & z) ^ (y & z));}
+function sha256_Sigma0256(x) {return (sha256_S(x, 2) ^ sha256_S(x, 13) ^ sha256_S(x, 22));}
+function sha256_Sigma1256(x) {return (sha256_S(x, 6) ^ sha256_S(x, 11) ^ sha256_S(x, 25));}
+function sha256_Gamma0256(x) {return (sha256_S(x, 7) ^ sha256_S(x, 18) ^ sha256_R(x, 3));}
+function sha256_Gamma1256(x) {return (sha256_S(x, 17) ^ sha256_S(x, 19) ^ sha256_R(x, 10));}
+function sha256_Sigma0512(x) {return (sha256_S(x, 28) ^ sha256_S(x, 34) ^ sha256_S(x, 39));}
+function sha256_Sigma1512(x) {return (sha256_S(x, 14) ^ sha256_S(x, 18) ^ sha256_S(x, 41));}
+function sha256_Gamma0512(x) {return (sha256_S(x, 1)  ^ sha256_S(x, 8) ^ sha256_R(x, 7));}
+function sha256_Gamma1512(x) {return (sha256_S(x, 19) ^ sha256_S(x, 61) ^ sha256_R(x, 6));}
+
+var sha256_K = new Array
+(
+  1116352408, 1899447441, -1245643825, -373957723, 961987163, 1508970993,
+  -1841331548, -1424204075, -670586216, 310598401, 607225278, 1426881987,
+  1925078388, -2132889090, -1680079193, -1046744716, -459576895, -272742522,
+  264347078, 604807628, 770255983, 1249150122, 1555081692, 1996064986,
+  -1740746414, -1473132947, -1341970488, -1084653625, -958395405, -710438585,
+  113926993, 338241895, 666307205, 773529912, 1294757372, 1396182291,
+  1695183700, 1986661051, -2117940946, -1838011259, -1564481375, -1474664885,
+  -1035236496, -949202525, -778901479, -694614492, -200395387, 275423344,
+  430227734, 506948616, 659060556, 883997877, 958139571, 1322822218,
+  1537002063, 1747873779, 1955562222, 2024104815, -2067236844, -1933114872,
+  -1866530822, -1538233109, -1090935817, -965641998
+);
+
+function binb_sha256(m, l)
+{
+  var HASH = new Array(1779033703, -1150833019, 1013904242, -1521486534,
+                       1359893119, -1694144372, 528734635, 1541459225);
+  var W = new Array(64);
+
+  /* append padding */
+  m[l >> 5] |= 0x80 << (24 - l % 32);
+  m[((l + 64 >> 9) << 4) + 15] = l;
+ 
+  for(var offset = 0; offset < m.length; offset += 16)
+    processBlock_sha256(m, offset, HASH, W);
+
+  return HASH;
+}
+
+/*
+ * Process a block of 16 4-byte words in m starting at offset and update HASH.  
+ * offset must be a multiple of 16 and less than m.length.  W is a scratchpad Array(64).
+ */
+function processBlock_sha256(m, offset, HASH, W) {
+    var a, b, c, d, e, f, g, h;
+    var j, T1, T2;
+    
+    a = HASH[0];
+    b = HASH[1];
+    c = HASH[2];
+    d = HASH[3];
+    e = HASH[4];
+    f = HASH[5];
+    g = HASH[6];
+    h = HASH[7];
+
+    for(j = 0; j < 64; j++)
+    {
+      if (j < 16) W[j] = m[j + offset];
+      else W[j] = safe_add(safe_add(safe_add(sha256_Gamma1256(W[j - 2]), W[j - 7]),
+                                            sha256_Gamma0256(W[j - 15])), W[j - 16]);
+
+      T1 = safe_add(safe_add(safe_add(safe_add(h, sha256_Sigma1256(e)), sha256_Ch(e, f, g)),
+                                                          sha256_K[j]), W[j]);
+      T2 = safe_add(sha256_Sigma0256(a), sha256_Maj(a, b, c));
+      h = g;
+      g = f;
+      f = e;
+      e = safe_add(d, T1);
+      d = c;
+      c = b;
+      b = a;
+      a = safe_add(T1, T2);
+    }
+
+    HASH[0] = safe_add(a, HASH[0]);
+    HASH[1] = safe_add(b, HASH[1]);
+    HASH[2] = safe_add(c, HASH[2]);
+    HASH[3] = safe_add(d, HASH[3]);
+    HASH[4] = safe_add(e, HASH[4]);
+    HASH[5] = safe_add(f, HASH[5]);
+    HASH[6] = safe_add(g, HASH[6]);
+    HASH[7] = safe_add(h, HASH[7]);
+}
+
+function safe_add (x, y)
+{
+  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
+  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
+  return (msw << 16) | (lsw & 0xFFFF);
+}
+
+/*
+ * Create a Sha256, call update(data) multiple times, then call finalize().
+ */
+var Sha256 = function Sha256() {
+    this.W = new Array(64);
+    this.hash = new Array(1779033703, -1150833019, 1013904242, -1521486534,
+                          1359893119, -1694144372, 528734635, 1541459225);
+    this.nTotalBytes = 0;
+    this.buffer = new Uint8Array(16 * 4);
+    this.nBufferBytes = 0;
+}
+
+/*
+ * Update the hash with data, which is Uint8Array.
+ */
+Sha256.prototype.update = function(data) {
+    this.nTotalBytes += data.length;
+    
+    if (this.nBufferBytes > 0) {
+        // Fill up the buffer and process it first.
+        var bytesNeeded = this.buffer.length - this.nBufferBytes;
+        if (data.length < bytesNeeded) {
+            this.buffer.set(data, this.nBufferBytes);
+            this.nBufferBytes += data.length;
+            return;
+        }
+        else {
+            this.buffer.set(data.subarray(0, bytesNeeded), this.nBufferBytes);
+            processBlock_sha256(byteArray2binb(this.buffer), 0, this.hash, this.W);
+            this.nBufferBytes = 0;
+            // Consume the bytes from data.
+            data = data.subarray(bytesNeeded, data.length);
+            if (data.length == 0)
+                return;
+        }
+    }
+    
+    // 2^6 is 16 * 4.
+    var nBlocks = data.length >> 6;
+    if (nBlocks > 0) {
+        var nBytes = nBlocks * 16 * 4;
+        var m = byteArray2binb(data.subarray(0, nBytes));
+        for(var offset = 0; offset < m.length; offset += 16)
+            processBlock_sha256(m, offset, this.hash, this.W);
+
+        data = data.subarray(nBytes, data.length);
+    }
+    
+    if (data.length > 0) {
+        // Save the remainder in the buffer.
+        this.buffer.set(data);
+        this.nBufferBytes = data.length;
+    }
+}
+
+/*
+ * Finalize the hash and return the result as Uint8Array.
+ * Only call this once.  Return values on subsequent calls are undefined.
+ */
+Sha256.prototype.finalize = function() {
+    var m = byteArray2binb(this.buffer.subarray(0, this.nBufferBytes));
+    /* append padding */
+    var l = this.nBufferBytes * 8;
+    m[l >> 5] |= 0x80 << (24 - l % 32);
+    m[((l + 64 >> 9) << 4) + 15] = this.nTotalBytes * 8;
+
+    for(var offset = 0; offset < m.length; offset += 16)
+        processBlock_sha256(m, offset, this.hash, this.W);
+
+    return Sha256.binb2Uint8Array(this.hash);
+}
+
+/*
+ * Convert an array of big-endian words to Uint8Array.
+ */
+Sha256.binb2Uint8Array = function(input)
+{
+    var output = new Uint8Array(input.length * 4);
+    var iOutput = 0;
+    for (var i = 0; i < input.length * 32; i += 8)
+        output[iOutput++] = (input[i>>5] >>> (24 - i % 32)) & 0xFF;
+    return output;
+}