	(function() {
/* ########## Begin module implementation ########## */
var sha1 = forge.sha1 = forge.sha1 || {};
forge.md = forge.md || {};
forge.md.algorithms = forge.md.algorithms || {};
forge.md.sha1 = forge.md.algorithms['sha1'] = sha1;

// sha-1 padding bytes not initialized yet
var _padding = null;
var _initialized = false;

/**
* Initializes the constant tables.
*/
var _init = function() {
  // create padding
  _padding = String.fromCharCode(128);
  _padding += forge.util.fillString(String.fromCharCode(0x00), 64);

  // now initialized
  _initialized = true;
};

/**
* Updates a SHA-1 state with the given byte buffer.
*
* @param s the SHA-1 state to update.
* @param w the array to use to store words.
* @param bytes the byte buffer to update with.
*/
var _update = function(s, w, bytes) {
  // consume 512 bit (64 byte) chunks
  var t, a, b, c, d, e, f, i;
  var len = bytes.length();
  while(len >= 64) {
    // the w array will be populated with sixteen 32-bit big-endian words
    // and then extended into 80 32-bit words according to SHA-1 algorithm
    // and for 32-79 using Max Locktyukhin's optimization

    // initialize hash value for this chunk
    a = s.h0;
    b = s.h1;
    c = s.h2;
    d = s.h3;
    e = s.h4;

    // round 1
    for(i = 0; i < 16; ++i) {
      t = bytes.getInt32();
      w[i] = t;
      f = d ^ (b & (c ^ d));
      t = ((a << 5) | (a >>> 27)) + f + e + 0x5A827999 + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }
    for(; i < 20; ++i) {
      t = (w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16]);
      t = (t << 1) | (t >>> 31);
      w[i] = t;
      f = d ^ (b & (c ^ d));
      t = ((a << 5) | (a >>> 27)) + f + e + 0x5A827999 + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }
    // round 2
    for(; i < 32; ++i) {
      t = (w[i - 3] ^ w[i - 8] ^ w[i - 14] ^ w[i - 16]);
      t = (t << 1) | (t >>> 31);
      w[i] = t;
      f = b ^ c ^ d;
      t = ((a << 5) | (a >>> 27)) + f + e + 0x6ED9EBA1 + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }
    for(; i < 40; ++i) {
      t = (w[i - 6] ^ w[i - 16] ^ w[i - 28] ^ w[i - 32]);
      t = (t << 2) | (t >>> 30);
      w[i] = t;
      f = b ^ c ^ d;
      t = ((a << 5) | (a >>> 27)) + f + e + 0x6ED9EBA1 + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }
    // round 3
    for(; i < 60; ++i) {
      t = (w[i - 6] ^ w[i - 16] ^ w[i - 28] ^ w[i - 32]);
      t = (t << 2) | (t >>> 30);
      w[i] = t;
      f = (b & c) | (d & (b ^ c));
      t = ((a << 5) | (a >>> 27)) + f + e + 0x8F1BBCDC + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }
    // round 4
    for(; i < 80; ++i) {
      t = (w[i - 6] ^ w[i - 16] ^ w[i - 28] ^ w[i - 32]);
      t = (t << 2) | (t >>> 30);
      w[i] = t;
      f = b ^ c ^ d;
      t = ((a << 5) | (a >>> 27)) + f + e + 0xCA62C1D6 + t;
      e = d;
      d = c;
      c = (b << 30) | (b >>> 2);
      b = a;
      a = t;
    }

    // update hash state
    s.h0 += a;
    s.h1 += b;
    s.h2 += c;
    s.h3 += d;
    s.h4 += e;

    len -= 64;
  }
};

/**
* Creates a SHA-1 message digest object.
*
* @return a message digest object.
*/
sha1.create = function() {
  // do initialization as necessary
  if(!_initialized) {
    _init();

  }

  // SHA-1 state contains five 32-bit integers
  var _state = null;

  // input buffer
  var _input = forge.util.createBuffer();

  // used for word storage
  var _w = new Array(80);

  // message digest object
  var md = {
    algorithm: 'sha1',
    blockLength: 64,
    digestLength: 20,
    // length of message so far (does not including padding)
    messageLength: 0
  };

  /**
* Starts the digest.
*
* @return this digest object.
*/
  md.start = function() {
    md.messageLength = 0;
    _input = forge.util.createBuffer();
    _state = {
      h0: 0x67452301,
      h1: 0xEFCDAB89,
      h2: 0x98BADCFE,
      h3: 0x10325476,
      h4: 0xC3D2E1F0
    };
    return md;
  };
  // start digest automatically for first time
  md.start();

  /**
* Updates the digest with the given message input. The given input can
* treated as raw input (no encoding will be applied) or an encoding of
* 'utf8' maybe given to encode the input using UTF-8.
*
* @param msg the message input to update with.
* @param encoding the encoding to use (default: 'raw', other: 'utf8').
*
* @return this digest object.
*/
  md.update = function(msg, encoding) {
    if(encoding === 'utf8') {
      msg = forge.util.encodeUtf8(msg);
    }

    // update message length
    md.messageLength += msg.length;

    // add bytes to input buffer
    _input.putBytes(msg);

    // process bytes
    _update(_state, _w, _input);

    // compact input buffer every 2K or if empty
    if(_input.read > 2048 || _input.length() === 0) {
      _input.compact();
    }

    return md;
  };

   /**
* Produces the digest.
*
* @return a byte buffer containing the digest value.
*/
   md.digest = function() {
    /* Note: Here we copy the remaining bytes in the input buffer and
add the appropriate SHA-1 padding. Then we do the final update
on a copy of the state so that if the user wants to get
intermediate digests they can do so. */

    /* Determine the number of bytes that must be added to the message
to ensure its length is congruent to 448 mod 512. In other words,
a 64-bit integer that gives the length of the message will be
appended to the message and whatever the length of the message is
plus 64 bits must be a multiple of 512. So the length of the
message must be congruent to 448 mod 512 because 512 - 64 = 448.

In order to fill up the message length it must be filled with
padding that begins with 1 bit followed by all 0 bits. Padding
must *always* be present, so if the message length is already
congruent to 448 mod 512, then 512 padding bits must be added. */

    // 512 bits == 64 bytes, 448 bits == 56 bytes, 64 bits = 8 bytes
    // _padding starts with 1 byte with first bit is set in it which
    // is byte value 128, then there may be up to 63 other pad bytes
    var len = md.messageLength;
    var padBytes = forge.util.createBuffer();
    padBytes.putBytes(_input.bytes());
    padBytes.putBytes(_padding.substr(0, 64 - ((len + 8) % 64)));

    /* Now append length of the message. The length is appended in bits
as a 64-bit number in big-endian order. Since we store the length
in bytes, we must multiply it by 8 (or left shift by 3). So here
store the high 3 bits in the low end of the first 32-bits of the
64-bit number and the lower 5 bits in the high end of the second
32-bits. */
    padBytes.putInt32((len >>> 29) & 0xFF);
    padBytes.putInt32((len << 3) & 0xFFFFFFFF);
    var s2 = {
      h0: _state.h0,
      h1: _state.h1,
      h2: _state.h2,
      h3: _state.h3,
      h4: _state.h4
    };
    _update(s2, _w, padBytes);
    var rval = forge.util.createBuffer();
    rval.putInt32(s2.h0);
    rval.putInt32(s2.h1);
    rval.putInt32(s2.h2);
    rval.putInt32(s2.h3);
    rval.putInt32(s2.h4);
    return rval;
  };

  md.digest2 = function() {
    /* Note: Here we copy the remaining bytes in the input buffer and
add the appropriate SHA-1 padding. Then we do the final update
on a copy of the state so that if the user wants to get
intermediate digests they can do so. */

    /* Determine the number of bytes that must be added to the message
to ensure its length is congruent to 448 mod 512. In other words,
a 64-bit integer that gives the length of the message will be
appended to the message and whatever the length of the message is
plus 64 bits must be a multiple of 512. So the length of the
message must be congruent to 448 mod 512 because 512 - 64 = 448.

In order to fill up the message length it must be filled with
padding that begins with 1 bit followed by all 0 bits. Padding
must *always* be present, so if the message length is already
congruent to 448 mod 512, then 512 padding bits must be added. */

    // 512 bits == 64 bytes, 448 bits == 56 bytes, 64 bits = 8 bytes
    // _padding starts with 1 byte with first bit is set in it which
    // is byte value 128, then there may be up to 63 other pad bytes
    var len = md.messageLength;
    var padBytes = forge.util.createBuffer();
	var c_input=forge.util.createBuffer(_input.data.slice(_input.read));
	var c_w=_w.slice(0);
    padBytes.putBytes(_input.bytes());
    padBytes.putBytes(_padding.substr(0, 64 - ((len + 8) % 64)));

    /* Now append length of the message. The length is appended in bits
as a 64-bit number in big-endian order. Since we store the length
in bytes, we must multiply it by 8 (or left shift by 3). So here
store the high 3 bits in the low end of the first 32-bits of the
64-bit number and the lower 5 bits in the high end of the second
32-bits. */
    padBytes.putInt32((len >>> 29) & 0xFF);
    padBytes.putInt32((len << 3) & 0xFFFFFFFF);
    var s2 = {
      h0: _state.h0,
      h1: _state.h1,
      h2: _state.h2,
      h3: _state.h3,
      h4: _state.h4
    };
    _update(s2, _w, padBytes);
    var rval = forge.util.createBuffer();
    rval.putInt32(s2.h0);
    rval.putInt32(s2.h1);
    rval.putInt32(s2.h2);
    rval.putInt32(s2.h3);
    rval.putInt32(s2.h4);
	_input=c_input;
	_w=c_w;
    return rval;
  };

  return md;
};
sha1.createHash=function() {
	var hash=sha1.create();
	var oupdate=hash.update;
	hash.update=function(data) {
		return oupdate(data.toString('binary'));
	};
	hash.digest=function() {
		return hash.digest2().toHex();
	};
	return hash;
};
})();