使用CCHmac生成一個HMAC swift sdk8.3（）

Question

在SDK8.3之前，我通過這種方式生成了我的hmac。現在我在CCHmac（）函數上出現錯誤。由於我是初學者，我無法弄清楚如何解決這個問題。在此先感謝您的幫助！

xcode的警告：不能involke 'CCHmac' 與類型的參數列表（UInt32的，[CCHAR] ?, UINT，[CCHAR] ?, UINT，INOUT [（CUnsignedChar）]

func generateHMAC(key: String, data: String) -> String { 

    let cKey = key.cStringUsingEncoding(NSUTF8StringEncoding) 
    let cData = data.cStringUsingEncoding(NSUTF8StringEncoding) 

    var result = [CUnsignedChar](count: Int(CC_SHA512_DIGEST_LENGTH), repeatedValue: 0) 
    CCHmac(CCHmacAlgorithm(kCCHmacAlgSHA512), cKey, strlen(cKey!), cData, strlen(cData!), &result) 


    let hash = NSMutableString() 
    for var i = 0; i < result.count; i++ { 
     hash.appendFormat("%02hhx", result[i]) 
    } 

    return hash as String 
} 

Answer 1

問題是strlen返回UInt，而CCHmac的長度參數是Int秒。

雖然你可以做一些強制，你可能也只是使用這兩個陣列的count財產而不是打電話給strlen。

func generateHMAC(key: String, data: String) -> String { 

    var result: [CUnsignedChar] 
    if let cKey = key.cStringUsingEncoding(NSUTF8StringEncoding), 
      cData = data.cStringUsingEncoding(NSUTF8StringEncoding) 
    { 
     let algo = CCHmacAlgorithm(kCCHmacAlgSHA512) 
     result = Array(count: Int(CC_SHA512_DIGEST_LENGTH), repeatedValue: 0) 

     CCHmac(algo, cKey, cKey.count-1, cData, cData.count-1, &result) 
    } 
    else { 
     // as @MartinR points out, this is in theory impossible 
     // but personally, I prefer doing this to using `!` 
     fatalError("Nil returned when processing input strings as UTF8") 
    } 

    let hash = NSMutableString() 
    for val in result { 
     hash.appendFormat("%02hhx", val) 
    } 

    return hash as String 
}