JavaScript SHA1加密算法实现详细代码

/* * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined * in FIPS 180-1 * Version 2.2 Copyright 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. * http://www.sharejs.com */ /* * 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 */function hex_sha1(s)  { return rstr2hex(rstr_sha1(str2rstr_utf8(s))); }function b64_sha1(s)  { return rstr2b64(rstr_sha1(str2rstr_utf8(s))); }function any_sha1(s, e) { return rstr2any(rstr_sha1(str2rstr_utf8(s)), e); }function hex_hmac_sha1(k, d) { return rstr2hex(rstr_hmac_sha1(str2rstr_utf8(k), str2rstr_utf8(d))); }function b64_hmac_sha1(k, d) { return rstr2b64(rstr_hmac_sha1(str2rstr_utf8(k), str2rstr_utf8(d))); }function any_hmac_sha1(k, d, e) { return rstr2any(rstr_hmac_sha1(str2rstr_utf8(k), str2rstr_utf8(d)), e); } /* * Perform a simple self-test to see if the VM is working */function sha1_vm_test(){ return hex_sha1("abc").toLowerCase() == "a9993e364706816aba3e25717850c26c9cd0d89d";} /* * Calculate the SHA1 of a raw string */function rstr_sha1(s){ return binb2rstr(binb_sha1(rstr2binb(s), s.length * 8));} /* * Calculate the HMAC-SHA1 of a key and some data (raw strings) */function rstr_hmac_sha1(key, data){ var bkey = rstr2binb(key); if(bkey.length > 16) bkey = binb_sha1(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_sha1(ipad.concat(rstr2binb(data)), 512 + data.length * 8); return binb2rstr(binb_sha1(opad.concat(hash), 512 + 160));} /* * 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){ var output = Array(input.length >> 2); 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;} /* * 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;} /* * Calculate the SHA-1 of an array of big-endian words, and a bit length */function binb_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] = bit_rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);   var t = safe_add(safe_add(bit_rol(a, 5), sha1_ft(j, b, c, d)),            safe_add(safe_add(e, w[j]), sha1_kt(j)));   e = d;   d = c;   c = bit_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;} /* * 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 bit_rol(num, cnt){ return (num << cnt) | (num >>> (32 - cnt));}