Base64 for Swift

base64.swift

let plainString = "foo"

// Encoding

guard let plainData = (plainString as NSString).dataUsingEncoding(NSUTF8StringEncoding) else {
    fatalError()
}

let base64String = plainData.base64EncodedStringWithOptions(NSDataBase64EncodingOptions(rawValue: 0))
print(base64String) // Zm9v

// Decoding

if let decodedData = NSData(base64EncodedString: base64String, options: NSDataBase64DecodingOptions(rawValue: 0)),
    let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding) {
        print(decodedString) // foo
}