JS base64 加密和解密

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/**** 加密 base64encode(utf16to8(str))* 解密 utf8to16(base64decode(str))***/var base64EncodeChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";  var base64DecodeChars = new Array(-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1);  /**  * base64編碼  * @param {Object} str  */  function base64encode(str){      var out, i, len;      var c1, c2, c3;      len = str.length;      i = 0;      out = "";      while (i < len) {          c1 = str.charCodeAt(i++) & 0xff;          if (i == len) {              out += base64EncodeChars.charAt(c1 >> 2);              out += base64EncodeChars.charAt((c1 & 0x3) << 4);              out += "==";              break;          }          c2 = str.charCodeAt(i++);          if (i == len) {              out += base64EncodeChars.charAt(c1 >> 2);              out += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));              out += base64EncodeChars.charAt((c2 & 0xF) << 2);              out += "=";              break;          }          c3 = str.charCodeAt(i++);          out += base64EncodeChars.charAt(c1 >> 2);          out += base64EncodeChars.charAt(((c1 & 0x3) << 4) | ((c2 & 0xF0) >> 4));          out += base64EncodeChars.charAt(((c2 & 0xF) << 2) | ((c3 & 0xC0) >> 6));          out += base64EncodeChars.charAt(c3 & 0x3F);      }      return out;  }  /**  * base64解碼  * @param {Object} str  */  function base64decode(str){      var c1, c2, c3, c4;      var i, len, out;      len = str.length;      i = 0;      out = "";      while (i < len) {          /* c1 */          do {              c1 = base64DecodeChars[str.charCodeAt(i++) & 0xff];          }          while (i < len && c1 == -1);          if (c1 == -1)               break;          /* c2 */          do {              c2 = base64DecodeChars[str.charCodeAt(i++) & 0xff];          }          while (i < len && c2 == -1);          if (c2 == -1)               break;          out += String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));          /* c3 */          do {              c3 = str.charCodeAt(i++) & 0xff;              if (c3 == 61)                   return out;              c3 = base64DecodeChars[c3];          }          while (i < len && c3 == -1);          if (c3 == -1)               break;          out += String.fromCharCode(((c2 & 0XF) << 4) | ((c3 & 0x3C) >> 2));          /* c4 */          do {              c4 = str.charCodeAt(i++) & 0xff;              if (c4 == 61)                   return out;              c4 = base64DecodeChars[c4];          }          while (i < len && c4 == -1);          if (c4 == -1)               break;          out += String.fromCharCode(((c3 & 0x03) << 6) | c4);      }      return out;  }  function utf16to8(str) {　　var out, i, len, c;　　out = "";　　len = str.length;　　for(i = 0; i < len; i++) { c = str.charCodeAt(i); if ((c >= 0x0001) && (c <= 0x007F)) {　　 out += str.charAt(i); } else if (c > 0x07FF) {　　 out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));　　 out += String.fromCharCode(0x80 | ((c >>　6) & 0x3F));　　 out += String.fromCharCode(0x80 | ((c >>　0) & 0x3F)); } else {　　 out += String.fromCharCode(0xC0 | ((c >>　6) & 0x1F));　　 out += String.fromCharCode(0x80 | ((c >>　0) & 0x3F)); }　　}　　return out;}function utf8to16(str) {　　var out, i, len, c;　　var char2, char3;　　out = "";　　len = str.length;　　i = 0;　　while(i < len) { c = str.charCodeAt(i++); switch(c >> 4) {　 case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:　　 // 0xxxxxxx　　 out += str.charAt(i-1);　　 break;　 case 12: case 13:　　 // 110x xxxx　 10xx xxxx　　 char2 = str.charCodeAt(i++);　　 out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));　　 break;　 case 14:　　 // 1110 xxxx　10xx xxxx　10xx xxxx　　 char2 = str.charCodeAt(i++);　　 char3 = str.charCodeAt(i++);　　 out += String.fromCharCode(((c & 0x0F) << 12) |　　　　((char2 & 0x3F) << 6) |　　　　((char3 & 0x3F) << 0));　　 break; }　　}　　return out;}

 

JS base64 加密和解密