[绍棠_Swift] Swift4.0如何实现字符串的HMAC_SHA1加密

一、 首先创建桥接头文件bridge.h来包含需要引用的Objective-C头文件，并在项目中配置

#import <CommonCrypto/CommonDigest.h>

#import <CommonCrypto/CommonHMAC.h>

二、 建立一个封装类，对String进行HMAC扩展

import Foundation

// MARK: - 加密  HMAC_SHA1/MD5/SHA1/SHA224......

/**  需在桥接文件导入头文件 ，因为C语言的库

 *   #import <CommonCrypto/CommonDigest.h>

 *   #import <CommonCrypto/CommonHMAC.h>

 */

enum CryptoAlgorithm {

    /// 加密的枚举选项

    case MD5, SHA1, SHA224, SHA256, SHA384, SHA512

    

    var HMACAlgorithm:
CCHmacAlgorithm {

        var result:
Int = 0

        switch self {

        case .MD5:      result =
kCCHmacAlgMD5

        case .SHA1:     result =
kCCHmacAlgSHA1

        case .SHA224:   result =
kCCHmacAlgSHA224

        case .SHA256:   result =
kCCHmacAlgSHA256

        case .SHA384:   result =
kCCHmacAlgSHA384

        case .SHA512:   result =
kCCHmacAlgSHA512

        }

        return CCHmacAlgorithm(result)

    }

    

    var digestLength:
Int {

        var result:
Int32 = 0

        switch self {

        case .MD5:      result =
CC_MD5_DIGEST_LENGTH

        case .SHA1:     result =
CC_SHA1_DIGEST_LENGTH

        case .SHA224:   result =
CC_SHA224_DIGEST_LENGTH

        case .SHA256:   result =
CC_SHA256_DIGEST_LENGTH

        case .SHA384:   result =
CC_SHA384_DIGEST_LENGTH

        case .SHA512:   result =
CC_SHA512_DIGEST_LENGTH

        }

        return Int(result)

    }

}

extension String {

    /*

     *   func：加密方法

     *   参数1：加密方式； 参数2：加密的key

     */

    func hmac(algorithm:
CryptoAlgorithm, key: String) ->
String {

        let str =
self.cString(using:
String.Encoding.utf8)

        let strLen =
Int(self.lengthOfBytes(using:
String.Encoding.utf8))

        let digestLen = algorithm.digestLength

        let result =
UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)

        let keyStr = key.cString(using:
String.Encoding.utf8)

        let keyLen =
Int(key.lengthOfBytes(using:
String.Encoding.utf8))

        

        CCHmac(algorithm.HMACAlgorithm, keyStr!, keyLen, str!, strLen, result)

        

        let digest =
stringFromResult(result:  result, length: digestLen)

        

        result.deallocate(capacity: digestLen)

        

        return digest

    }

    

    private func stringFromResult(result:
UnsafeMutablePointer<CUnsignedChar>, length:
Int) -> String {

        let hash =
NSMutableString()

        for i in 0..<length {

            hash.appendFormat("%02x", result[i])

        }

        return String(hash)

    }

}

注意： swift4.0中不支持同名函数了

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