Swift中的CommonHMAC

Question

我正在尝试在Swift中创建字符串的HMAC SHA-1哈希,但无法弄清楚如何与API进行交互,因为它似乎没有导入CommonCrypto框架.我尝试了各种不同形式的"import CommonCrypto"并创建了一个桥接头文件,但没有一个有所作为.

奇怪的是,如果我创建一个Objective-C类,我可以毫无问题地与API交互,所以这似乎是Swift独有的.

如果有人能告诉我uint8_t digest[CC_SHA1_DIGEST_LENGTH]Swift中的等价物,我会非常感激

Answer 1

你可以在Swift中完成.只需确保添加#import <CommonCrypto/CommonHMAC.h>到桥接的Objective-C桥接头.

更新:对于Swift 4,请在此处使用Swift Package Manager查看更好的解决方案:https://github.com/jernejstrasner/SwiftCrypto

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)
    }
}

extension String {

    func hmac(algorithm: CryptoAlgorithm, key: String) -> String {
        let str = self.cStringUsingEncoding(NSUTF8StringEncoding)
        let strLen = Int(self.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
        let digestLen = algorithm.digestLength
        let result = UnsafeMutablePointer<CUnsignedChar>.alloc(digestLen)
        let keyStr = key.cStringUsingEncoding(NSUTF8StringEncoding)
        let keyLen = Int(key.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))

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

        let digest = stringFromResult(result, length: digestLen)

        result.dealloc(digestLen)

        return digest
    }

    private func stringFromResult(result: UnsafeMutablePointer<CUnsignedChar>, length: Int) -> String {
        var hash = NSMutableString()
        for i in 0..<length {
            hash.appendFormat("%02x", result[i])
        }
        return String(hash)
    }

}

Answer 2

试试这个Swift 3.1:

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)
    }
}

extension String {

    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)
    }

}

不要忘记添加#import <CommonCrypto/CommonHMAC.h>到Header.h