public void ComputeSignature()
{
SignedXmlDebugLog.LogBeginSignatureComputation(this, _context);
BuildDigestedReferences();
// Load the key
AsymmetricAlgorithm key = SigningKey;
if (key == null)
{
throw new CryptographicException(SR.Cryptography_Xml_LoadKeyFailed);
}
// Check the signature algorithm associated with the key so that we can accordingly set the signature method
if (SignedInfo.SignatureMethod == null)
{
if (key is DSA)
{
SignedInfo.SignatureMethod = XmlDsigDSAUrl;
}
else if (key is RSA)
{
// Default to RSA-SHA1
if (SignedInfo.SignatureMethod == null)
{
SignedInfo.SignatureMethod = XmlDsigRSASHA256Url;
}
}
else
{
throw new CryptographicException(SR.Cryptography_Xml_CreatedKeyFailed);
}
}
// See if there is a signature description class defined in the Config file
SignatureDescription signatureDescription = CryptoHelpers.CreateFromName <SignatureDescription>(SignedInfo.SignatureMethod);
if (signatureDescription == null)
{
throw new CryptographicException(SR.Cryptography_Xml_SignatureDescriptionNotCreated);
}
HashAlgorithm hashAlg = signatureDescription.CreateDigest();
if (hashAlg == null)
{
throw new CryptographicException(SR.Cryptography_Xml_CreateHashAlgorithmFailed);
}
byte[] hashvalue = GetC14NDigest(hashAlg);
AsymmetricSignatureFormatter asymmetricSignatureFormatter = signatureDescription.CreateFormatter(key);
SignedXmlDebugLog.LogSigning(this, key, signatureDescription, hashAlg, asymmetricSignatureFormatter);
m_signature.SignatureValue = asymmetricSignatureFormatter.CreateSignature(hashAlg);
}
public void ComputeSignature(KeyedHashAlgorithm macAlg)
{
if (macAlg == null)
{
throw new ArgumentNullException(nameof(macAlg));
}
if (!(macAlg is HMAC hash))
{
throw new CryptographicException(SR.Cryptography_Xml_SignatureMethodKeyMismatch);
}
int signatureLength;
if (m_signature.SignedInfo.SignatureLength == null)
{
signatureLength = hash.HashSize;
}
else
{
signatureLength = Convert.ToInt32(m_signature.SignedInfo.SignatureLength, null);
}
// signatureLength should be less than hash size
if (signatureLength < 0 || signatureLength > hash.HashSize)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidSignatureLength);
}
if (signatureLength % 8 != 0)
{
throw new CryptographicException(SR.Cryptography_Xml_InvalidSignatureLength2);
}
BuildDigestedReferences();
SignedInfo.SignatureMethod = hash.HashName switch
{
"SHA1" => SignedXml.XmlDsigHMACSHA1Url,
"SHA256" => SignedXml.XmlDsigMoreHMACSHA256Url,
"SHA384" => SignedXml.XmlDsigMoreHMACSHA384Url,
"SHA512" => SignedXml.XmlDsigMoreHMACSHA512Url,
"MD5" => SignedXml.XmlDsigMoreHMACMD5Url,
"RIPEMD160" => SignedXml.XmlDsigMoreHMACRIPEMD160Url,
_ => throw new CryptographicException(SR.Cryptography_Xml_SignatureMethodKeyMismatch),
};
byte[] hashValue = GetC14NDigest(hash);
SignedXmlDebugLog.LogSigning(this, hash);
m_signature.SignatureValue = new byte[signatureLength / 8];
Buffer.BlockCopy(hashValue, 0, m_signature.SignatureValue, 0, signatureLength / 8);
}