Created
July 11, 2014 08:04
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b64.js
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_.base64encode = function(string) { | |
var padding = '=', | |
chrTable = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz' + | |
'0123456789+/'; | |
function utf8Encode(str) { | |
var bytes = [], offset = 0, length, char; | |
str = encodeURI(str); | |
length = str.length; | |
while (offset < length) { | |
char = str[offset]; | |
offset += 1; | |
if ('%' !== char) { | |
bytes.push(char.charCodeAt(0)); | |
} else { | |
char = str[offset] + str[offset + 1]; | |
bytes.push(parseInt(char, 16)); | |
offset += 2; | |
} | |
} | |
return bytes; | |
} | |
var result = '', | |
bytes = utf8Encode(string), | |
length = bytes.length, | |
i; | |
// Convert every three bytes to 4 ascii characters. | |
for (i = 0; i < (length - 2); i += 3) { | |
result += chrTable[bytes[i] >> 2]; | |
result += chrTable[((bytes[i] & 0x03) << 4) + (bytes[i+1] >> 4)]; | |
result += chrTable[((bytes[i+1] & 0x0f) << 2) + (bytes[i+2] >> 6)]; | |
result += chrTable[bytes[i+2] & 0x3f]; | |
} | |
// Convert the remaining 1 or 2 bytes, pad out to 4 characters. | |
if (length%3) { | |
i = length - (length%3); | |
result += chrTable[bytes[i] >> 2]; | |
if ((length%3) === 2) { | |
result += chrTable[((bytes[i] & 0x03) << 4) + (bytes[i+1] >> 4)]; | |
result += chrTable[(bytes[i+1] & 0x0f) << 2]; | |
result += padding; | |
} else { | |
result += chrTable[(bytes[i] & 0x03) << 4]; | |
result += padding + padding; | |
} | |
} | |
return result; | |
}; |
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