【实践】Swift3 封装加密工具类CryptoHelper

使用OC的CommonCrypto库完成对swift的加密/解密工具类的封装。支持散列哈希(MD5, SHA1, SHA224, SHA256, SHA384, SHA512)及AES加密

1.引入CommonCrypto库

#import <CommonCrypto/CommonHMAC.h>
#import <CommonCrypto/CommonDigest.h>
#import <CommonCrypto/CommonCryptor.h>

2.创建CryptoAlgorithm枚举

enum CryptoAlgorithm{

    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)
    }
}

3.创建String扩展

extension String{

    var md5 : String!{
        let str = self.cString(using: String.Encoding.utf8)
        let strLen = CC_LONG(self.lengthOfBytes(using: String.Encoding.utf8))
        let digestLen = Int(CC_MD5_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)
        CC_MD5(str!, strLen, result)
        return stringFromBytes(bytes: result, length: digestLen)
    }


    var sha1: String! {
        let str = self.cString(using: String.Encoding.utf8)
        let strLen = CC_LONG(self.lengthOfBytes(using: String.Encoding.utf8))
        let digestLen = Int(CC_SHA1_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)
        CC_SHA1(str!, strLen, result)
        return stringFromBytes(bytes: result, length: digestLen)
    }


    var sha256String: String! {
        let str = self.cString(using: String.Encoding.utf8)
        let strLen = CC_LONG(self.lengthOfBytes(using: String.Encoding.utf8))
        let digestLen = Int(CC_SHA256_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)
        CC_SHA256(str!, strLen, result)
        return stringFromBytes(bytes: result, length: digestLen)
    }


    var sha512String: String! {
        let str = self.cString(using: String.Encoding.utf8)
        let strLen = CC_LONG(self.lengthOfBytes(using: String.Encoding.utf8))
        let digestLen = Int(CC_SHA512_DIGEST_LENGTH)
        let result = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: digestLen)
        CC_SHA512(str!, strLen, result)
        return stringFromBytes(bytes: result, length: digestLen)
    }


    func stringFromBytes(bytes: UnsafeMutablePointer<CUnsignedChar>, length: Int) -> String{
        let hash = NSMutableString()
        for i in 0..<length {
            hash.appendFormat("%02x", bytes[i])
        }
        bytes.deallocate(capacity: length)
        return String(format: hash as String)
    }

    //HMAC 加密
    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
    }

    //十六进制转换
    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)
    }

    //AES 加密
    func aes(operation: CCOperation,key: String) -> String{
        let keyData             = key.data(using: String.Encoding.utf8)! as NSData
        let keyLen              = Int(kCCKeySizeAES128)
        let keyBytes            = keyData.bytes

        let strData             = self.data(using: String.Encoding.utf8)! as NSData
        let dataLen             = strData.length
        let dataBytes           = strData.bytes

        let cryptLength         = Int(dataLen + kCCBlockSizeAES128)
        let cryptPointer        = UnsafeMutablePointer<CUnsignedChar>.allocate(capacity: cryptLength)

        let algoritm            = CCAlgorithm(kCCAlgorithmAES128)
        let option              = CCOptions(kCCOptionPKCS7Padding|kCCOptionECBMode)

        let numBytesEncrypted   = UnsafeMutablePointer<Int>.allocate(capacity: 1)
        numBytesEncrypted.initialize(to: 1)

        let cryptStatus         = CCCrypt(operation, algoritm, option, keyBytes, keyLen, nil, dataBytes, dataLen, cryptPointer, cryptLength, numBytesEncrypted)


        if CCStatus(cryptStatus) == CCStatus(kCCSuccess){
            let len = Int(numBytesEncrypted.pointee)
            let digest = stringFromResult(result: cryptPointer, length: len)
            numBytesEncrypted.deallocate(capacity: 1)
            return digest
        }else{
            return ""
        }
      }
    }

3.测试

    let str = "cyfhaha"
    let aesResult = "814514553e4bc8f7ca3edf9341e81c49"

    ALinLog("---------:\(str.hmac(algorithm: .SHA1, key: "chengyanfang"))")

    ALinLog("---------:\(str.sha1)")

    ALinLog("---------:\(str.aes(operation: CCOperation(kCCEncrypt), key: "chengyanfang"))")

    ALinLog("---------:\(aesResult.aes(operation: CCOperation(kCCDecrypt), key: "chengyanfang"))")

打印结果:

  ---------:c792b6aac08880924ece052105cf06d1117789a9
  ---------:3506bc4ecb80abf331b28b0bf18b35aadebe6518
  ---------:814514553e4bc8f7ca3edf9341e81c49
  ---------:cyfhaha