Swift加密MD5_32bit分大小写

extension NSString {

    func md532BitLower() -> String? {

        let cStr = utf8CString

        let result = [UInt8](repeating: 0, count: 16)

        let num = Int(truncating: strlen(cStr))

        CC_MD5(cStr, num, result)

        return String(format: "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", result[0], result[1], result[2], result[3], result[4], result[5], result[6], result[7], result[8], result[9], result[10], result[11], result[12], result[13], result[14], result[15]).lowercased()

    }

    func md532BitUpper() -> String? {

        let cStr = utf8CString

        let result = [UInt8](repeating: 0, count: 16)

        let num = Int(truncating: strlen(cStr))

        CC_MD5(cStr, num, result)

        return String(format: "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", result[0], result[1], result[2], result[3], result[4], result[5], result[6], result[7], result[8], result[9], result[10], result[11], result[12], result[13], result[14], result[15]).uppercased()

}