You can verfify RSA SHA512 signatures but you'll have to implement and register the signature description by yourself.
Signature description:
public sealed class RSAPKCS1SHA512SignatureDescription : SignatureDescription
{
public RSAPKCS1SHA512SignatureDescription()
{
KeyAlgorithm = typeof( RSACryptoServiceProvider ).FullName;
DigestAlgorithm = typeof( SHA512Managed ).FullName;
FormatterAlgorithm = typeof( RSAPKCS1SignatureFormatter ).FullName;
DeformatterAlgorithm = typeof( RSAPKCS1SignatureDeformatter ).FullName;
}
public override AsymmetricSignatureDeformatter CreateDeformatter( AsymmetricAlgorithm key )
{
if( key == null )
{
throw new ArgumentNullException( "key" );
}
var deformatter = new RSAPKCS1SignatureDeformatter( key );
deformatter.SetHashAlgorithm( "SHA512" );
return deformatter;
}
public override AsymmetricSignatureFormatter CreateFormatter( AsymmetricAlgorithm key )
{
if( key == null )
{
throw new ArgumentNullException( "key" );
}
var formatter = new RSAPKCS1SignatureFormatter( key );
formatter.SetHashAlgorithm( "SHA512" );
return formatter;
}
}
In your code you'll have to register this description with CryptoConfig:
const string XmlDsigRsaSha512 = "http://www.w3.org/2001/04/xmldsig-more#rsa-sha512";
CryptoConfig.AddAlgorithm( typeof( RSAPKCS1SHA512SignatureDescription ), XmlDsigRsaSha512 );
I tested it with .Net 4.0 on Windows 7 64 Bit.