JavaScript实现的SHA-1加密算法完整实例_javascript技巧

/**
*
* Secure Hash Algorithm (SHA1)
* http://www.webtoolkit.info/
*
**/
function SHA1 (msg) {
  function rotate_left(n,s) {
    var t4 = ( n<>>(32-s));
    return t4;
  };
  function lsb_hex(val) {
    var str="";
    var i;
    var vh;
    var vl;
    for( i=0; i<=6; i+=2 ) {
      vh = (val>>>(i*4+4))&0x0f;
      vl = (val>>>(i*4))&0x0f;
      str += vh.toString(16) + vl.toString(16);
    }
    return str;
  };
  function cvt_hex(val) {
    var str="";
    var i;
    var v;
    for( i=7; i>=0; i-- ) {
      v = (val>>>(i*4))&0x0f;
      str += v.toString(16);
    }
    return str;
  };
  function Utf8Encode(string) {
    string = string.replace(/\r\n/g,"\n");
    var utftext = "";
    for (var n = 0; n < string.length; n++) {
      var c = string.charCodeAt(n);
      if (c < 128) {
        utftext += String.fromCharCode(c);
      }
      else if((c > 127) && (c < 2048)) {
        utftext += String.fromCharCode((c >> 6) | 192);
        utftext += String.fromCharCode((c & 63) | 128);
      }
      else {
        utftext += String.fromCharCode((c >> 12) | 224);
        utftext += String.fromCharCode(((c >> 6) & 63) | 128);
        utftext += String.fromCharCode((c & 63) | 128);
      }
    }
    return utftext;
  };
  var blockstart;
  var i, j;
  var W = new Array(80);
  var H0 = 0x67452301;
  var H1 = 0xEFCDAB89;
  var H2 = 0x98BADCFE;
  var H3 = 0x10325476;
  var H4 = 0xC3D2E1F0;
  var A, B, C, D, E;
  var temp;
  msg = Utf8Encode(msg);
  var msg_len = msg.length;
  var word_array = new Array();
  for( i=0; i>>29 );
  word_array.push( (msg_len<<3)&0x0ffffffff );
  for ( blockstart=0; blockstart