Swift 中的 CommonHMAC

使用Swift编程语言可以轻松地实现各种功能，包括加密和解密数据。其中，CommonHMAC是Swift中一个非常有用的功能，它可以用于生成HMAC（哈希消息认证码）。

swift
import CommonCrypto
func generateHMAC(key: Data, data: Data) -> Data? {
    var hmac = [UInt8](repeating: 0, count: Int(CC_SHA256_DIGEST_LENGTH))
    
    key.withUnsafeBytes { keyBytes in
        data.withUnsafeBytes { dataBytes in
            CCHmac(CCHmacAlgorithm(kCCHmacAlgSHA256),
                   keyBytes.baseAddress, keyBytes.count,
                   dataBytes.baseAddress, dataBytes.count,
                   &hmac)
        }
    }
    
    return Data(hmac)
}
let key = "mySecretKey".data(using: .utf8)!
let data = "Hello, World!".data(using: .utf8)!
if let hmac = generateHMAC(key: key, data: data) {
    print("HMAC: \(hmac.map { String(format: "%02hhx", $0) }.joined())")
} else {
    print("Failed to generate HMAC")
}