带SHA256的SignedXml计算签名

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“指定的无效算法”。 signedXml.ComputeSignature(); 。 谁能告诉我我做错了什么？