swift sh256

func sha256(data : Data) -> Data {
        var hash = [UInt8](repeating: 0,  count: Int(CC_SHA256_DIGEST_LENGTH))
        data.withUnsafeBytes {
            _ = CC_SHA256($0.baseAddress, CC_LONG(data.count), &hash)
        }
        return Data(hash)
    }


    @IBAction func touch(_ sender: Any) {
        let data = "123456".data(using: String.Encoding.utf8)
        print(sha256(data: data!).base64EncodedString())
    }