diff --git a/src/js/sha1.js b/src/js/sha1.js
new file mode 100644
index 0000000..1b55982
--- /dev/null
+++ b/src/js/sha1.js
@@ -0,0 +1,202 @@
+/*
+ * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
+ * in FIPS PUB 180-1
+ * Version 2.1a Copyright Paul Johnston 2000 - 2002.
+ * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
+ * Distributed under the BSD License
+ * See http://pajhome.org.uk/crypt/md5 for details.
+ */
+
+/*
+ * 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   */
+var chrsz   = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */
+
+/*
+ * These are the functions you'll usually want to call
+ * They take string arguments and return either hex or base-64 encoded strings
+ */
+function hex_sha1(s){return binb2hex(core_sha1(str2binb(s),s.length * chrsz));}
+function b64_sha1(s){return binb2b64(core_sha1(str2binb(s),s.length * chrsz));}
+function str_sha1(s){return binb2str(core_sha1(str2binb(s),s.length * chrsz));}
+function hex_hmac_sha1(key, data){ return binb2hex(core_hmac_sha1(key, data));}
+function b64_hmac_sha1(key, data){ return binb2b64(core_hmac_sha1(key, data));}
+function str_hmac_sha1(key, data){ return binb2str(core_hmac_sha1(key, data));}
+
+/*
+ * Perform a simple self-test to see if the VM is working
+ */
+function sha1_vm_test()
+{
+  return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";
+}
+
+/*
+ * Calculate the SHA-1 of an array of big-endian words, and a bit length
+ */
+function core_sha1(x, len)
+{
+  /* append padding */
+  x[len >> 5] |= 0x80 << (24 - len % 32);
+  x[((len + 64 >> 9) << 4) + 15] = len;
+
+  var w = Array(80);
+  var a =  1732584193;
+  var b = -271733879;
+  var c = -1732584194;
+  var d =  271733878;
+  var e = -1009589776;
+
+  for(var i = 0; i < x.length; i += 16)
+  {
+    var olda = a;
+    var oldb = b;
+    var oldc = c;
+    var oldd = d;
+    var olde = e;
+
+    for(var j = 0; j < 80; j++)
+    {
+      if(j < 16) w[j] = x[i + j];
+      else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
+      var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
+                       safe_add(safe_add(e, w[j]), sha1_kt(j)));
+      e = d;
+      d = c;
+      c = rol(b, 30);
+      b = a;
+      a = t;
+    }
+
+    a = safe_add(a, olda);
+    b = safe_add(b, oldb);
+    c = safe_add(c, oldc);
+    d = safe_add(d, oldd);
+    e = safe_add(e, olde);
+  }
+  return Array(a, b, c, d, e);
+
+}
+
+/*
+ * Perform the appropriate triplet combination function for the current
+ * iteration
+ */
+function sha1_ft(t, b, c, d)
+{
+  if(t < 20) return (b & c) | ((~b) & d);
+  if(t < 40) return b ^ c ^ d;
+  if(t < 60) return (b & c) | (b & d) | (c & d);
+  return b ^ c ^ d;
+}
+
+/*
+ * Determine the appropriate additive constant for the current iteration
+ */
+function sha1_kt(t)
+{
+  return (t < 20) ?  1518500249 : (t < 40) ?  1859775393 :
+         (t < 60) ? -1894007588 : -899497514;
+}
+
+/*
+ * Calculate the HMAC-SHA1 of a key and some data
+ */
+function core_hmac_sha1(key, data)
+{
+  var bkey = str2binb(key);
+  if(bkey.length > 16) bkey = core_sha1(bkey, key.length * chrsz);
+
+  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 = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);
+  return core_sha1(opad.concat(hash), 512 + 160);
+}
+
+/*
+ * Add integers, wrapping at 2^32. This uses 16-bit operations internally
+ * to work around bugs in some JS interpreters.
+ */
+function safe_add(x, y)
+{
+  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
+  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
+  return (msw << 16) | (lsw & 0xFFFF);
+}
+
+/*
+ * Bitwise rotate a 32-bit number to the left.
+ */
+function rol(num, cnt)
+{
+  return (num << cnt) | (num >>> (32 - cnt));
+}
+
+/*
+ * Convert an 8-bit or 16-bit string to an array of big-endian words
+ * In 8-bit function, characters >255 have their hi-byte silently ignored.
+ */
+function str2binb(str)
+{
+  var bin = Array();
+  var mask = (1 << chrsz) - 1;
+  for(var i = 0; i < str.length * chrsz; i += chrsz)
+    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (32 - chrsz - i%32);
+  return bin;
+}
+
+/*
+ * Convert an array of big-endian words to a string
+ */
+function binb2str(bin)
+{
+  var str = "";
+  var mask = (1 << chrsz) - 1;
+  for(var i = 0; i < bin.length * 32; i += chrsz)
+    str += String.fromCharCode((bin[i>>5] >>> (32 - chrsz - i%32)) & mask);
+  return str;
+}
+
+/*
+ * Convert an array of big-endian words to a hex string.
+ */
+function binb2hex(binarray)
+{
+  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
+  var str = "";
+  for(var i = 0; i < binarray.length * 4; i++)
+  {
+    str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +
+           hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8  )) & 0xF);
+  }
+  return str;
+}
+
+/*
+ * Convert an array of big-endian words to a base-64 string
+ */
+function binb2b64(binarray)
+{
+  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+  var str = "";
+  for(var i = 0; i < binarray.length * 4; i += 3)
+  {
+    var triplet = (((binarray[i   >> 2] >> 8 * (3 -  i   %4)) & 0xFF) << 16)
+                | (((binarray[i+1 >> 2] >> 8 * (3 - (i+1)%4)) & 0xFF) << 8 )
+                |  ((binarray[i+2 >> 2] >> 8 * (3 - (i+2)%4)) & 0xFF);
+    for(var j = 0; j < 4; j++)
+    {
+      if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
+      else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
+    }
+  }
+  return str;
+}