FWPNT9wz

1import Foundation
2import CommonCrypto
3
4extension Data {
5    enum Algorithm {
6        case md5
7        case sha1
8        case sha224
9        case sha256
10        case sha384
11        case sha512
12        
13        var digestLength: Int {
14            switch self {
15            case .md5: return Int(CC_MD5_DIGEST_LENGTH)
16            case .sha1: return Int(CC_SHA1_DIGEST_LENGTH)
17            case .sha224: return Int(CC_SHA224_DIGEST_LENGTH)
18            case .sha256: return Int(CC_SHA256_DIGEST_LENGTH)
19            case .sha384: return Int(CC_SHA384_DIGEST_LENGTH)
20            case .sha512: return Int(CC_SHA512_DIGEST_LENGTH)
21            }
22        }
23    }
24}
25
26extension Data.Algorithm: RawRepresentable {
27    typealias RawValue = Int
28    
29    init?(rawValue: Int) {
30        switch rawValue {
31        case kCCHmacAlgMD5: self = .md5
32        case kCCHmacAlgSHA1: self = .sha1
33        case kCCHmacAlgSHA224: self = .sha224
34        case kCCHmacAlgSHA256: self = .sha256
35        case kCCHmacAlgSHA384: self = .sha384
36        case kCCHmacAlgSHA512: self = .sha512
37        default: return nil
38        }
39    }
40    
41    var rawValue: Int {
42        switch self {
43        case .md5: return kCCHmacAlgMD5
44        case .sha1: return kCCHmacAlgSHA1
45        case .sha224: return kCCHmacAlgSHA224
46        case .sha256: return kCCHmacAlgSHA256
47        case .sha384: return kCCHmacAlgSHA384
48        case .sha512: return kCCHmacAlgSHA512
49        }
50    }
51}
52
53extension Data {
54    func authenticationCode(for algorithm: Algorithm, secretKey: String = "") -> Data {
55        guard let secretKeyData = secretKey.data(using: .utf8) else { fatalError() }
56        return authenticationCode(for: algorithm, secretKey: secretKeyData)
57    }
58    
59    func authenticationCode(for algorithm: Algorithm, secretKey: Data) -> Data {
60        let hashBytes = UnsafeMutablePointer<UInt8>.allocate(capacity: algorithm.digestLength)
61        defer { hashBytes.deallocate() }
62        withUnsafeBytes { (bytes) -> Void in
63            secretKey.withUnsafeBytes { (secretKeyBytes) -> Void in
64                CCHmac(CCHmacAlgorithm(algorithm.rawValue), secretKeyBytes, secretKey.count, bytes, count, hashBytes)
65            }
66        }
67        return Data(bytes: hashBytes, count: algorithm.digestLength)
68    }
69}