在iOS中生成SHA256

Question

我试图生成SHA256在iOS使用奥术库与以下数据：

字符串：Amount=50

键：71DD0F73AFFB47825FF9864DDE95F3B

结果是409dc622b3bef5c9fc46e45c3210111fcb4536d3a55833316fe0dc8154b3ea34

我认为这是正确的。但是，Windows对应程序正在使用以下代码生成SHA256：

Windows Phone Source Code:

public static string HmacSha256(string secretKey, string value)
    {
        var msg = CryptographicBuffer.ConvertStringToBinary(value, BinaryStringEncoding.Utf8);
        byte[] convertedHash = new byte[secretKey.Length / 2];

        for (int i = 0; i < secretKey.Length / 2; i++)
        {
            convertedHash[i] = (byte)Int32.Parse(secretKey.Substring(i * 2, 2), System.Globalization.NumberStyles.HexNumber);
        }

        // Create HMAC.
        var objMacProv = MacAlgorithmProvider.OpenAlgorithm(MacAlgorithmNames.HmacSha256);
        CryptographicHash hash = objMacProv.CreateHash(convertedHash.AsBuffer());

        hash.Append(msg);
        return CryptographicBuffer.EncodeToHexString(hash.GetValueAndReset());

    }

结果是：94a20ca39c8487c7763823ec9c918d9e38ae83cb741439f6d129bcdef9edba73，这与我得到的不同。有人能帮我一下吗？让我知道上面的代码在做什么，我如何在iOS中复制它。

编辑：

 iOS Source code

 let key = self.md5(string: "71DD0F73AFFBB47825FF9864DDE95F3B")

    let hash = HMAC.SHA256(str, key: key)




Answer 1

html prettyprint-override">#import <CommonCrypto/CommonHMAC.h>

+ (NSString *)hmacSHA256EncryptString{


    NSString * parameterSecret = @"input secret key";
    NSString *plainString = @"input encrypt content string";
    const char *secretKey  = [parameterSecret cStringUsingEncoding:NSUTF8StringEncoding];
    const char *plainData = [plainString cStringUsingEncoding:NSUTF8StringEncoding];
    unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
    CCHmac(kCCHmacAlgSHA256, secretKey, strlen(secretKey), plainData, strlen(plainData), cHMAC);
    NSData *HMACData = [NSData dataWithBytes:cHMAC length:sizeof(cHMAC)];
    const unsigned char *bufferChar = (const unsigned char *)[HMACData bytes];
    NSMutableString *hmacString = [NSMutableString stringWithCapacity:HMACData.length * 2];
    for (int i = 0; i < HMACData.length; ++i){
        [hmacString appendFormat:@"%02x", bufferChar[i]];
    }
    return hmacString;
    
}

Answer 2

Windows代码接受字符串，将其解释为十六进制数，并将每次两个字符转换为一个字节。

你的Mac代码最喜欢的是字符串。由于密钥以“71”开头，windows代码将其作为一个单字节，值为0x71=129，Mac代码将其作为两个字节，值为“7”=55，“1”=49。

你所需要做的就是在Mac上转换字节，就像在Windows上一样。你可能不得不做一些不可思议的事情，看看Mac库的源代码，看看它是如何进行实际的哈希计算的。

Answer 3

这里的关键是您需要将您的秘密（十六进制字符串）转换为NSData。换句话说，NSData字节流将看起来像秘密。

这应该满足您的要求：

    // Hex string to NSData conversion from here http://stackoverflow.com/questions/7317860/converting-hex-nsstring-to-nsdata
    NSString *secret = @"71DD0F73AFFBB47825FF9864DDE95F3B";
    NSData *dataIn = [@"Amount=50&BillerID=59&ChannelID=2&Context=34|check|test&ReturnURL=https://uat.myfatoora.com/ReceiptPOC.aspx&TxnRefNum=000000000020003&UserName=DCS" dataUsingEncoding:NSUTF8StringEncoding];
    NSMutableData *macOut = [NSMutableData dataWithLength:CC_SHA256_DIGEST_LENGTH];

    secret = [secret stringByReplacingOccurrencesOfString:@" " withString:@""];
    NSMutableData *secretData = [[NSMutableData alloc] init];
    unsigned char whole_byte;
    char byte_chars[3] = {'\0','\0','\0'};
    int i;
    for (i=0; i < [secret length]/2; i++) {
        byte_chars[0] = [secret characterAtIndex:i*2];
        byte_chars[1] = [secret characterAtIndex:i*2+1];
        whole_byte = strtol(byte_chars, NULL, 16);
        [secretData appendBytes:&whole_byte length:1];
    }

    CCHmac(kCCHmacAlgSHA256, secretData.bytes, secretData.length, dataIn.bytes, dataIn.length, macOut.mutableBytes);

    NSMutableString *stringOut = [NSMutableString stringWithCapacity:macOut.length];
    const unsigned char *macOutBytes = macOut.bytes;

    for (NSInteger i=0; i<macOut.length; ++i) {
        [stringOut appendFormat:@"%02x", macOutBytes[i]];
    }

    NSLog(@"dataIn: %@", dataIn);
    NSLog(@"macOut: %@", macOut);
    NSLog(@"stringOut: %@", stringOut);

输出：

2016-09-27 20:18:54.181JKS[27562:5321334]dataIn：

2016-09-27 20:18:54.181JKS[27562:5321334]macOut：

2016-09-27 20:18:54.181JKS[27562:5321334]stringOut： 94a20ca39c8487c7763823ec9c918d9e38ae83cb741439f6d129bcdef9edba73

用Swift更新（代码应该清理）

// http://stackoverflow.com/questions/29799361/generate-a-hmac-swift-sdk8-3-using-cchmac
func generateHMAC(key: String, data: String) -> String {
    let keyData = key.dataFromHexadecimalString()! as NSData
    let dataIn = data.data(using: .utf8)! as NSData
    var result: [CUnsignedChar]
    result = Array(repeating: 0, count: Int(CC_SHA256_DIGEST_LENGTH))
    CCHmac(CCHmacAlgorithm(kCCHmacAlgSHA256), keyData.bytes, keyData.length, dataIn.bytes, dataIn.length, &result)

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

    return hash as String
}

您可以使用此扩展名将十六进制字符串转换为数据

// Modified slightly http://stackoverflow.com/questions/26501276/converting-hex-string-to-nsdata-in-swift
extension String {

    func dataFromHexadecimalString() -> Data? {
        var data = Data(capacity: characters.count / 2)

        let regex = try! NSRegularExpression(pattern: "[0-9a-f]{1,2}", options: .caseInsensitive)
        regex.enumerateMatches(in: self, options: [], range: NSMakeRange(0, characters.count)) { match, flags, stop in
            let byteString = (self as NSString).substring(with: match!.range)
            var num = UInt8(byteString, radix: 16)
            data.append(&num!, count: 1)
        }

        return data
    }
}

并使用do某事，如：

    let secret = "71DD0F73AFFBB47825FF9864DDE95F3B"
    let value = "Amount=50&BillerID=59&ChannelID=2&Context=34|check|test&ReturnURL=https://uat.myfatoora.com/ReceiptPOC.aspx&TxnRefNum=000000000020003&UserName=DCS"

    print("\(generateHMAC(key: secret, data: value))")

你的输出应该是94a20ca39c8487c7763823ec9c918d9e38ae83cb741439f6d129bcdef9edba73

您将需要#导入