我正在尝试使用SHA256对XML文档进行数字签名。
我正在尝试使用Security.Cryptography.dll。
这是我的代码 -
CryptoConfig.AddAlgorithm(typeof(RSAPKCS1SHA256SignatureDescription),"http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");
X509Certificate2 cert = new X509Certificate2(@"location of pks file", "password");
XmlDocument doc = new XmlDocument();
doc.PreserveWhitespace = true;
doc.Load(@"input.xml");
SignedXml signedXml = new SignedXml(doc);
signedXml.SigningKey = cert.PrivateKey;
signedXml.SignedInfo.SignatureMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";
//
// Add a signing reference, the uri is empty and so the whole document
// is signed.
Reference reference = new Reference();
reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
reference.AddTransform(new XmlDsigExcC14NTransform());
reference.Uri = "";
signedXml.AddReference(reference);
//
// Add the certificate as key info, because of this the certificate
// with the public key will be added in the signature part.
KeyInfo keyInfo = new KeyInfo();
keyInfo.AddClause(new KeyInfoX509Data(cert));
signedXml.KeyInfo = keyInfo;
// Generate the signature.
signedXml.ComputeSignature();
但我得到“指定了无效的算法”。 signedXml.ComputeSignature();处的错误。谁能告诉我我做错了什么？
答案 0 :(得分：30)
X509Certificate2将私有密钥从pfx文件加载到 Microsoft增强加密提供程序v1.0 （提供程序类型1又名PROV_RSA_FULL）中，而不是＆＃ 39; t支持SHA-256。
基于CNG的加密提供程序（在Vista和Server 2008中引入）支持的算法比基于CryptoAPI的提供程序更多，但.NET代码似乎仍在使用基于CryptoAPI的类，如RSACryptoServiceProvider而不是RSACng所以我们必须解决这些限制。
但是，另一个CryptoAPI提供程序， Microsoft增强型RSA和AES加密提供程序（提供程序类型24 a.k.a。PROV_RSA_AES）确实支持SHA-256。因此，如果我们将私钥发送到此提供商，我们可以使用它进行签名。
首先，您必须调整X509Certificate2构造函数，以便通过添加X509Certificate2标记将密钥从X509KeyStorageFlags.Exportable放入的提供程序中导出：
X509Certificate2 cert = new X509Certificate2(
@"location of pks file", "password",
X509KeyStorageFlags.Exportable);
导出私钥：
var exportedKeyMaterial = cert.PrivateKey.ToXmlString(
/* includePrivateParameters = */ true);
然后为支持SHA-256的提供程序创建一个新的RSACryptoServiceProvider实例：
var key = new RSACryptoServiceProvider(
new CspParameters(24 /* PROV_RSA_AES */));
key.PersistKeyInCsp = false;
并将私钥导入其中：
key.FromXmlString(exportedKeyMaterial);
当您创建了SignedXml个实例后，请告诉它使用key而不是cert.PrivateKey：
signedXml.SigningKey = key;
现在它将起作用。
以下是MSDN上的list of provider types and their codes。
以下是您的示例的完整调整代码：
CryptoConfig.AddAlgorithm(typeof(RSAPKCS1SHA256SignatureDescription), "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256");
X509Certificate2 cert = new X509Certificate2(@"location of pks file", "password", X509KeyStorageFlags.Exportable);
// Export private key from cert.PrivateKey and import into a PROV_RSA_AES provider:
var exportedKeyMaterial = cert.PrivateKey.ToXmlString( /* includePrivateParameters = */ true);
var key = new RSACryptoServiceProvider(new CspParameters(24 /* PROV_RSA_AES */));
key.PersistKeyInCsp = false;
key.FromXmlString(exportedKeyMaterial);
XmlDocument doc = new XmlDocument();
doc.PreserveWhitespace = true;
doc.Load(@"input.xml");
SignedXml signedXml = new SignedXml(doc);
signedXml.SigningKey = key;
signedXml.SignedInfo.SignatureMethod = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256";
//
// Add a signing reference, the uri is empty and so the whole document
// is signed.
Reference reference = new Reference();
reference.AddTransform(new XmlDsigEnvelopedSignatureTransform());
reference.AddTransform(new XmlDsigExcC14NTransform());
reference.Uri = "";
signedXml.AddReference(reference);
//
// Add the certificate as key info, because of this the certificate
// with the public key will be added in the signature part.
KeyInfo keyInfo = new KeyInfo();
keyInfo.AddClause(new KeyInfoX509Data(cert));
signedXml.KeyInfo = keyInfo;
// Generate the signature.
signedXml.ComputeSignature();
答案 1 :(得分：15)
导出和重新导入已经been given as an answer，但您还应该了解其他几个选项。
GetRSAPrivateKey（扩展名）方法返回＆＃34;最佳可用类型＆＃34;的RSA实例。对于密钥和平台（而不是PrivateKey属性，＃34;每个人都知道＆＃34;返回RSACryptoServiceProvider）。
在99.99（％）％的所有RSA私钥中，此方法返回的对象能够生成SHA-2签名。
虽然在.NET 4.6（.0）中添加了该方法，但在这种情况下存在4.6.2的要求，因为从GetRSAPrivateKey返回的RSA实例不能与SignedXml一起使用。从那以后been fixed（162556）。
我个人不喜欢这种方法，因为它使用（现在遗留的）PrivateKey属性和RSACryptoServiceProvider类。但是，它具有处理所有.NET Framework版本的优势（尽管在非Windows系统上不是.NET Core，因为RSACryptoServiceProvider仅适用于Windows）。
private static RSACryptoServiceProvider UpgradeCsp(RSACryptoServiceProvider currentKey)
{
const int PROV_RSA_AES = 24;
CspKeyContainerInfo info = currentKey.CspKeyContainerInfo;
// WARNING: 3rd party providers and smart card providers may not handle this upgrade.
// You may wish to test that the info.ProviderName value is a known-convertible value.
CspParameters cspParameters = new CspParameters(PROV_RSA_AES)
{
KeyContainerName = info.KeyContainerName,
KeyNumber = (int)info.KeyNumber,
Flags = CspProviderFlags.UseExistingKey,
};
if (info.MachineKeyStore)
{
cspParameters.Flags |= CspProviderFlags.UseMachineKeyStore;
}
if (info.ProviderType == PROV_RSA_AES)
{
// Already a PROV_RSA_AES, copy the ProviderName in case it's 3rd party
cspParameters.ProviderName = info.ProviderName;
}
return new RSACryptoServiceProvider(cspParameters);
}
如果您已将cert.PrivateKey转换为RSACryptoServiceProvider，则可以通过UpgradeCsp发送它。由于这是打开现有密钥，因此没有额外的材料写入磁盘，它使用与现有密钥相同的权限，并且不需要您进行导出。
但是（请注意！）不要设置PersistKeyInCsp = false，因为这将在克隆关闭时删除原始密钥。
答案 2 :(得分：2)
如果升级到.Net 4.7.1或更高版本后遇到此问题：
.Net 4.7及更低版本：
SignedXml signedXml = new SignedXml(doc);
signedXml.SigningKey = cert.PrivateKey;
.net 4.7.1及更高版本：
SignedXml signedXml = new SignedXml(doc);
signedXml.SigningKey = cert.GetRSAPrivateKey();
弗拉基米尔·科赞西奇
的积分答案 3 :(得分：0)
在 dotnet core 中，我有这个：
var xml = new SignedXml(request) {SigningKey = privateKey};
xml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;
xml.SignedInfo.SignatureMethod = SignedXml.XmlDsigSHA256Url;
xml.KeyInfo = keyInfo;
xml.AddReference(reference);
xml.ComputeSignature();
没有用。相反，我使用了这个
var xml = new SignedXml(request) {SigningKey = privateKey};
xml.SignedInfo.CanonicalizationMethod = SignedXml.XmlDsigExcC14NTransformUrl;
xml.SignedInfo.SignatureMethod = SignedXml.XmlDsigRSASHA256Url;
xml.KeyInfo = keyInfo;
xml.AddReference(reference);
xml.ComputeSignature();
更改签名方法 => xml.SignedInfo.SignatureMethod = SignedXml.XmlDsigRSASHA256Url