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1 var keyStr = "ABCDEFGHIJKLMNOP" + |
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2 "QRSTUVWXYZabcdef" + |
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3 "ghijklmnopqrstuv" + |
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4 "wxyz0123456789+/" + |
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5 "="; |
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6 |
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7 var Base64 = { |
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8 |
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9 encode: function (input) { |
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10 input = escape(input); |
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11 var output = ""; |
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12 var chr1, chr2, chr3 = ""; |
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13 var enc1, enc2, enc3, enc4 = ""; |
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14 var i = 0; |
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15 |
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16 do { |
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17 chr1 = input.charCodeAt(i++); |
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18 chr2 = input.charCodeAt(i++); |
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19 chr3 = input.charCodeAt(i++); |
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20 |
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21 enc1 = chr1 >> 2; |
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22 enc2 = ((chr1 & 3) << 4) | (chr2 >> 4); |
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23 enc3 = ((chr2 & 15) << 2) | (chr3 >> 6); |
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24 enc4 = chr3 & 63; |
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25 |
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26 if (isNaN(chr2)) { |
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27 enc3 = enc4 = 64; |
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28 } else if (isNaN(chr3)) { |
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29 enc4 = 64; |
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30 } |
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31 |
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32 output = output + |
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33 keyStr.charAt(enc1) + |
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34 keyStr.charAt(enc2) + |
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35 keyStr.charAt(enc3) + |
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36 keyStr.charAt(enc4); |
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37 chr1 = chr2 = chr3 = ""; |
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38 enc1 = enc2 = enc3 = enc4 = ""; |
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39 } while (i < input.length); |
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40 |
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41 return output; |
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42 } |
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43 |
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44 , decode : function (input) { |
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45 var output = ""; |
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46 var chr1, chr2, chr3 = ""; |
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47 var enc1, enc2, enc3, enc4 = ""; |
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48 var i = 0; |
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49 |
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50 // remove all characters that are not A-Z, a-z, 0-9, +, /, or = |
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51 var base64test = /[^A-Za-z0-9\+\/\=]/g; |
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52 if (base64test.exec(input)) { |
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53 alert("There were invalid base64 characters in the input text.\n" + |
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54 "Valid base64 characters are A-Z, a-z, 0-9, '+', '/',and '='\n" + |
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55 "Expect errors in decoding."); |
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56 } |
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57 input = input.replace(/[^A-Za-z0-9\+\/\=]/g, ""); |
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58 |
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59 do { |
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60 enc1 = keyStr.indexOf(input.charAt(i++)); |
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61 enc2 = keyStr.indexOf(input.charAt(i++)); |
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62 enc3 = keyStr.indexOf(input.charAt(i++)); |
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63 enc4 = keyStr.indexOf(input.charAt(i++)); |
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64 |
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65 chr1 = (enc1 << 2) | (enc2 >> 4); |
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66 chr2 = ((enc2 & 15) << 4) | (enc3 >> 2); |
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67 chr3 = ((enc3 & 3) << 6) | enc4; |
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68 |
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69 output = output + String.fromCharCode(chr1); |
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70 |
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71 if (enc3 != 64) { |
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72 output = output + String.fromCharCode(chr2); |
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73 } |
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74 if (enc4 != 64) { |
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75 output = output + String.fromCharCode(chr3); |
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76 } |
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77 |
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78 chr1 = chr2 = chr3 = ""; |
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79 enc1 = enc2 = enc3 = enc4 = ""; |
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80 |
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81 } while (i < input.length); |
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82 |
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83 return unescape(output); |
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84 } |
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85 } |