今天在swift组件模块化的时候，有一个生成动态口令的功能，发现使用的谷歌的OC类，很是不爽。
于是就自己写一个了一个动态口令解密的代码
原来旧代码展示：

let gtmString = GTMStringEncoding()
        let secretData = gtmString.base32Decode(keyString)
        let generator = TOTPGenerator.init(secret: secretData, algorithm: "SHA1", digits: 6, period: TOTPGenerator.defaultPeriod())
        let str = generator?.generateOTP(for: Date())

我们采用swift OneTimePassword
pod引入

 pod 'OneTimePassword'

swift TOTPGenerator的实现

import OneTimePassword
class TOTPGenerator {
    private var totpGenerator: Generator?

    init?(secret: Data) {
        guard let generator = Generator(
            factor: .timer(period: 30),
            secret: secret,
            algorithm: .sha1,
            digits: 6) else {
                return nil
        }
        self.totpGenerator = generator
    }

    func generateOTP(for date: Date = Date()) -> String? {
        guard let generator = self.totpGenerator else { return nil }
        do {
            let password = try generator.password(at: date)
            return password
        } catch {
            return nil
        }
    }
}

最后使用方法改完之后的新代码：

 guard let secretData = base32Decode(keyString) else { return }
        let generator = TOTPGenerator(secret: secretData)
        let str = generator?.generateOTP(for: Date())

运行正常显示完成