swift3 - Swift 3 制作 sha1、sha256 和 md5 函数

Question

在 Swift 2 中，我使用以下代码扩展字符串变量并能够生成 sha1、sha256 和 md5。

移至 swift 3 后，代码不再起作用!我试图转换它，但遇到连续错误。

知道我该如何解决这个问题吗？

extension NSData {
    func hexString() -> String {
        var string = String()
        for i in UnsafeBufferPointer<UInt8>(start: UnsafeMutablePointer<UInt8>(bytes), count: length) {
            string += Int(i).hexString()
        }
        return string
    }

    func MD5() -> NSData {
        let result = NSMutableData(length: Int(CC_MD5_DIGEST_LENGTH))!
        CC_MD5(bytes, CC_LONG(length), UnsafeMutablePointer<UInt8>(result.mutableBytes))
        return NSData(data: result)
    }

    func SHA1() -> NSData {
        let result = NSMutableData(length: Int(CC_SHA1_DIGEST_LENGTH))!
        CC_SHA1(bytes, CC_LONG(length), UnsafeMutablePointer<UInt8>(result.mutableBytes))
        return NSData(data: result)
    }

    func SHA256() -> NSData {
        let result = NSMutableData(length: Int(CC_SHA256_DIGEST_LENGTH))
        CC_SHA256(bytes, CC_LONG(length), UnsafeMutablePointer(result!.mutableBytes))
        return NSData(data: result!)
    }
}

extension String {
    func hexString() -> String {
        return (self as NSString).dataUsingEncoding(NSUTF8StringEncoding)!.hexString()
    }

    func MD5() -> String {
        return (self as NSString).dataUsingEncoding(NSUTF8StringEncoding)!.MD5().hexString()
    }

    func SHA1() -> String {
        return (self as NSString).dataUsingEncoding(NSUTF8StringEncoding)!.SHA1().hexString()
    }

    func SHA256() -> String {
        return (self as NSString).dataUsingEncoding(NSUTF8StringEncoding)!.SHA256().hexString()
    }

}

Answer 1

你最好用 Swift Data在 swift 3 中。

Data

当与 Data 一起工作时，您需要使用 withUnsafeBytes(_:)或 withUnsafeMutableBytes(_:) ，您在何处使用 bytes或 mutableBytes分别。

withUnsafeBytes(_:)

withUnsafeMutableBytes(_:)

extension Data {
    func hexString() -> String {
        let string = self.map{Int($0).hexString()}.joined()
        return string
    }

    func MD5() -> Data {
        var result = Data(count: Int(CC_MD5_DIGEST_LENGTH))
        _ = result.withUnsafeMutableBytes {resultPtr in
            self.withUnsafeBytes {(bytes: UnsafePointer<UInt8>) in
                CC_MD5(bytes, CC_LONG(count), resultPtr)
            }
        }
        return result
    }

    /*
    ... nearly the same for `SHA1` and `SHA256`.
     */
}

extension String {
    func hexString() -> String {
        return self.data(using: .utf8)!.hexString()
    }

    func MD5() -> String {
        return self.data(using: .utf8)!.MD5().hexString()
    }

    /*
    ... nearly the same for `SHA1` and `SHA256`.
     */
}

我更喜欢计算属性而不是无参数方法(对于相对较轻的任务)。您需要使用它们修复所有部分，但您可以编写如下内容:

extension Int {
    var hexString: String {
        return ...
    }
}
extension Data {
    var hexString: String {
        let string = self.map{Int($0).hexString}.joined()
        return string
    }

    var MD5: Data {
        var result = Data(count: Int(CC_MD5_DIGEST_LENGTH))
        _ = result.withUnsafeMutableBytes {resultPtr in
            self.withUnsafeBytes {(bytes: UnsafePointer<UInt8>) in
                CC_MD5(bytes, CC_LONG(count), resultPtr)
            }
        }
        return result
    }

    /*
    ... nearly the same for `SHA1` and `SHA256`.
     */
}

extension String {
    var hexString: String {
        return self.data(using: .utf8)!.hexString
    }

    var MD5: String {
        return self.data(using: .utf8)!.MD5.hexString
    }

    /*
    ... nearly the same for `SHA1` and `SHA256`.
     */
}

使用 NSData 可能会更快地修复您的代码，但我建议您移至 Data在 swift 3 中。