我正在从不提供 .net 实现的提供商（cardinity）实现信用卡支付方式。我正在寻找类似的东西并最终编写自己的东西，因为我的谷歌技能似乎是......
我需要的是 javax.crypto.mac 的 base64 字符串
我支持以下方法：
enum EncryptionMethods
{
None=0,
HMACSHA1,
HMACSHA256,
HMACSHA384,
HMACSHA512,
HMACMD5
}
我已经通过以下方式实现了您上面的代码、SecretKeySpec 和 Mac（您需要 System.Security.Cryptography.ProtectedData）：
internal class Protected
{
private Byte[] salt = Guid.NewGuid().ToByteArray();
protected byte[] Protect(byte[] data)
{
try
{
return ProtectedData.Protect(data, salt, DataProtectionScope.CurrentUser);
}
catch (CryptographicException)//no reason for hackers to know it failed
{
return null;
}
}
protected byte[] Unprotect(byte[] data)
{
try
{
return ProtectedData.Unprotect(data, salt, DataProtectionScope.CurrentUser);
}
catch (CryptographicException)//no reason for hackers to know it failed
{
return null;
}
}
}
internal class SecretKeySpec:Protected,IDisposable
{
readonly EncryptionMethods _method;
private byte[] _secretKey;
public SecretKeySpec(byte[] secretKey, EncryptionMethods encryptionMethod)
{
_secretKey = Protect(secretKey);
_method = encryptionMethod;
}
public EncryptionMethods Method => _method;
public byte[] SecretKey => Unprotect( _secretKey);
public void Dispose()
{
if (_secretKey == null)
return;
//overwrite array memory
for (int i = 0; i < _secretKey.Length; i++)
{
_secretKey[i] = 0;
}
//set-null
_secretKey = null;
}
~SecretKeySpec()
{
Dispose();
}
}
internal class Mac : Protected,IDisposable
{
byte[] rawHmac;
HMAC mac;
public Mac(SecretKeySpec key, string data)
{
switch (key.Method)
{
case EncryptionMethods.HMACMD5:
mac = new HMACMD5(key.SecretKey);
break;
case EncryptionMethods.HMACSHA512:
mac = new HMACSHA512(key.SecretKey);
break;
case EncryptionMethods.HMACSHA384:
mac = new HMACSHA384(key.SecretKey);
break;
case EncryptionMethods.HMACSHA256:
mac = new HMACSHA256(key.SecretKey);
break;
case EncryptionMethods.HMACSHA1:
mac = new HMACSHA1(key.SecretKey);
break;
default:
throw new NotSupportedException("not supported HMAC");
}
rawHmac = Protect( mac.ComputeHash(Cardinity.ENCODING.GetBytes(data)));
}
public string AsBase64()
{
return System.Convert.ToBase64String(Unprotect(rawHmac));
}
public void Dispose()
{
if (rawHmac != null)
{
//overwrite memory address
for (int i = 0; i < rawHmac.Length; i++)
{
rawHmac[i] = 0;
}
//release memory now
rawHmac = null;
}
mac?.Dispose();
mac = null;
}
~Mac()
{
Dispose();
}
}
我已经通过以下方式在 OAuthSigner 类中实现了这一点：
public override string ComputeSignature(string plainTextToEncode, string consumerSecret)
{
var key = PercentEncode(consumerSecret) + "&";
try
{
using (var secretKey = new SecretKeySpec(key.GetBytes(), EncryptionMethods.HMACSHA1))
using (Mac mac = new Mac(secretKey, plainTextToEncode))
{
return mac.AsBase64();
}
}
finally
{
key = null;//free memory, remove sensitive data
}
}
然后，这不是您要求的，但我需要一个辅助方法，因为我将文本发送到这样的 Web 服务，并且我将其包括在内，因为有些人可能会复制代码：
public static String PercentEncode(string textToEncode)
{
return string.IsNullOrEmpty(textToEncode)
?""
: UrlEncoder.Default.Encode(Cardinity.ENCODING.GetString(Cardinity.ENCODING.GetBytes(textToEncode)))
.Replace("+", "%20").Replace("*", "%2A")
.Replace("%7E", "~");
}
UrlEncoder 类来自 System.Text.Encodings.Web，您可能需要添加引用。
名为 Cardinity 的类实现了我用于 Cardinity 的 Encoding 的“捷径”
public abstract class Cardinity
{
...
public static String API_BASE = "https://api.cardinity.com";
public static String API_VERSION = "v1";
public static String VERSION = "0.1";
public static String ENCODING_CHARSET = "UTF-8";
public static Encoding ENCODING => Encoding.UTF8;
}
由于 Java 经常使用 string.GetBytes，我为此添加了一个扩展方法，我在上面的key.GetBytes()中调用它，这是扩展代码：
public static byte[] GetBytes(this string sender)=>
Cardinity.ENCODING.GetBytes(sender);
我的测试方法，我已经复制了 Cardinity API传递的值，没有任何问题。
private OAuthSigner signer;
public HmacOAuthSigner_Test()
{
signer = new HmacOAuthSigner();
}
[TestMethod]
public void Test_HmacOAuthSigner_ComputeSignature_DefaultText()
{
var expects = "PxkffxyQh6jsDNcgJ23GpAxs2y8=";
var test_data = "justsomerandommessage";
var secretkey = "yvp0leodf231ihv9u29uuq6w8o4cat9qz2nkvs55oeu833s621";
var actual = signer.ComputeSignature(test_data, secretkey);
Assert.AreEqual(expects, actual, $"Expecting {test_data} to return {expects} received {actual}");
}
HmacOAuthSigner 的完整实现在这里，它实现了一个带有 PercentEncode 方法的抽象类。
public class HmacOAuthSigner : OAuthSigner
{
public override string ComputeSignature(string signatureBaseString, string consumerSecret)
{
var key = PercentEncode(consumerSecret) + "&";
var secretKey = new SecretKeySpec(key.GetBytes(), EncryptionMethods.HMACSHA1);
using (Mac mac = new Mac(secretKey, signatureBaseString))
{
return mac.AsBase64();
}
}
public override string GetSignatureMethod()
{
return "HMAC-SHA1";
}
}
以及我用作所有实现合同的抽象类：
public abstract class OAuthSigner
{
/// <summary>
/// Signature method used
/// </summary>
/// <returns>a string that tells the implementation method</returns>
public abstract string GetSignatureMethod();
/// <summary>
/// computes the signature that is used with the encryption based on the keys provided by cardinity
/// </summary>
/// <param name="signatureBaseString">The secret string that services as a base</param>
/// <param name="consumerSecret">The consumer key as specified in the API settings</param>
/// <returns>signature string computed by the provided parameters using the signature method</returns>
public abstract string ComputeSignature(String signatureBaseString, String consumerSecret);
/// <summary>
/// Encode a string into a format expected by Cardinity
/// </summary>
/// <param name="textToEncode">The text that is to be encoded</param>
/// <returns>web encoded string ready for using to send to Cardinity</returns>
public static String PercentEncode(string textToEncode)
{
return string.IsNullOrEmpty(textToEncode)
?""
: UrlEncoder.Default.Encode(Cardinity.ENCODING.GetString(Cardinity.ENCODING.GetBytes(textToEncode)))
.Replace("+", "%20").Replace("*", "%2A")
.Replace("%7E", "~");
}
}