/**
 * Secure Hash Algorithm with 160-bit digest (SHA-1) implementation.
 *
 * @author Dave Longley
 *
 * Copyright (c) 2010-2015 Digital Bazaar, Inc.
 */
(function() {
/* ########## Begin module implementation ########## */
function initModule(forge) {

var sha1 = forge.sha1 = forge.sha1 || {};

// used for word storage
var _w;

// FIXME: backwards compatibility
sha1.create = function() {
  return forge.md.createMessageDigest('sha1');
};

sha1.Algorithm = function() {
  this.name = 'sha1',
  this.blockSize = 64;
  this.digestLength = 20;
  this.messageLengthSize = 8;
};

sha1.Algorithm.prototype.start = function() {
  if(!_w) {
    _w = new Array(80);
  }
  return _createState();
};

sha1.Algorithm.prototype.writeMessageLength = function(
  finalBlock, messageLength) {
  // message length is in bits and in big-endian order; simply append
  finalBlock.putBuffer(messageLength);
};

sha1.Algorithm.prototype.digest = function(s, input) {
  // consume 512 bit (64 byte) chunks
  var t, a, b, c, d, e, f, i;
  var len = input.length();
  while(len >= 64) {
    // initialize hash value for this chunk
    a = s.h0;
    b = s.h1;
    c = s.h2;
    d = s.h3;
    e = s.h4;

    // 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

    // round 1
    for(i = 0; i < 16; ++i) {
      t = input.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 = (s.h0 + a) | 0;
    s.h1 = (s.h1 + b) | 0;
    s.h2 = (s.h2 + c) | 0;
    s.h3 = (s.h3 + d) | 0;
    s.h4 = (s.h4 + e) | 0;

    len -= 64;
  }

  return s;
};

forge.md.registerAlgorithm('sha1', new forge.sha1.Algorithm());

function _createState() {
  var state = {
    h0: 0x67452301,
    h1: 0xEFCDAB89,
    h2: 0x98BADCFE,
    h3: 0x10325476,
    h4: 0xC3D2E1F0
  };
  state.copy = function() {
    var rval = _createState();
    rval.h0 = state.h0;
    rval.h1 = state.h1;
    rval.h2 = state.h2;
    rval.h3 = state.h3;
    rval.h4 = state.h4;
    return rval;
  };
  state.write = function(buffer) {
    buffer.putInt32(state.h0);
    buffer.putInt32(state.h1);
    buffer.putInt32(state.h2);
    buffer.putInt32(state.h3);
    buffer.putInt32(state.h4);
  };
  return state;
}

} // end module implementation

/* ########## Begin module wrapper ########## */
var name = 'sha1';
if(typeof define !== 'function') {
  // NodeJS -> AMD
  if(typeof module === 'object' && module.exports) {
    var nodeJS = true;
    define = function(ids, factory) {
      factory(require, module);
    };
  } else {
    // <script>
    if(typeof forge === 'undefined') {
      forge = {};
    }
    return initModule(forge);
  }
}
// AMD
var deps;
var defineFunc = function(require, module) {
  module.exports = function(forge) {
    var mods = deps.map(function(dep) {
      return require(dep);
    }).concat(initModule);
    // handle circular dependencies
    forge = forge || {};
    forge.defined = forge.defined || {};
    if(forge.defined[name]) {
      return forge[name];
    }
    forge.defined[name] = true;
    for(var i = 0; i < mods.length; ++i) {
      mods[i](forge);
    }
    return forge[name];
  };
};
var tmpDefine = define;
define = function(ids, factory) {
  deps = (typeof ids === 'string') ? factory.slice(2) : ids.slice(2);
  if(nodeJS) {
    delete define;
    return tmpDefine.apply(null, Array.prototype.slice.call(arguments, 0));
  }
  define = tmpDefine;
  return define.apply(null, Array.prototype.slice.call(arguments, 0));
};
define(['require', 'module', './util', './md'], function() {
  defineFunc.apply(null, Array.prototype.slice.call(arguments, 0));
});
})();