private bool CheckSignedInfo(IMac macAlg)
{
if (macAlg == null)
{
throw new ArgumentNullException(nameof(macAlg));
}
SignedXmlDebugLog.LogBeginCheckSignedInfo(this, m_signature.SignedInfo);
int signatureLength;
if (m_signature.SignedInfo.SignatureLength == null)
{
signatureLength = macAlg.GetMacSize() * 8;
}
else
{
signatureLength = Convert.ToInt32(m_signature.SignedInfo.SignatureLength, null);
}
// signatureLength should be less than hash size
if (signatureLength < 0 || signatureLength > macAlg.GetMacSize() * 8)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_InvalidSignatureLength);
}
if (signatureLength % 8 != 0)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_InvalidSignatureLength2);
}
if (m_signature.SignatureValue == null)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_SignatureValueRequired);
}
if (m_signature.SignatureValue.Length != signatureLength / 8)
{
throw new System.Security.Cryptography.CryptographicException(SR.Cryptography_Xml_InvalidSignatureLength);
}
// Calculate the hash
GetC14NDigest(new MacHashWrapper(macAlg));
byte[] hashValue = new byte[macAlg.GetMacSize()];
macAlg.DoFinal(hashValue, 0);
SignedXmlDebugLog.LogVerifySignedInfo(this, macAlg, hashValue, m_signature.SignatureValue);
for (int i = 0; i < m_signature.SignatureValue.Length; i++)
{
if (m_signature.SignatureValue[i] != hashValue[i])
{
return(false);
}
}
return(true);
}
