C# Sign file with Bouncy Castle Windows XP

Question

i have a project in C# where i have to sign the files making them .p7m with envelope cryptographic CAdES, i made it with BouncyCastle. Now, the signing process it works perfectly on Windows 7 , 8 , 10 , but when i tested it on windows xp , there was an error

This is the function that sign files

SHA256Managed hashSha256 = new SHA256Managed();
byte[] certHash = hashSha256.ComputeHash(cert.RawData);
EssCertIDv2 essCert1 = new EssCertIDv2(new Org.BouncyCastle.Asn1.X509.AlgorithmIdentifier("2.16.840.1.101.3.4.2.1"), certHash);
SigningCertificateV2 scv2 = new SigningCertificateV2(new EssCertIDv2[] { essCert1 });
Org.BouncyCastle.Asn1.Cms.Attribute CertHAttribute = new Org.BouncyCastle.Asn1.Cms.Attribute(Org.BouncyCastle.Asn1.Pkcs.PkcsObjectIdentifiers.IdAASigningCertificateV2, new DerSet(scv2));
Asn1EncodableVector v = new Asn1EncodableVector();
v.Add(CertHAttribute);
Org.BouncyCastle.Asn1.Cms.AttributeTable AT = new Org.BouncyCastle.Asn1.Cms.AttributeTable(v);
CmsSignedDataGenWithRsaCsp cms = new CmsSignedDataGenWithRsaCsp();
Org.BouncyCastle.Crypto.AsymmetricKeyParameter keyParameter = null;
dynamic rsa = (RSACryptoServiceProvider)cert.PrivateKey;
Org.BouncyCastle.X509.X509Certificate certCopy = DotNetUtilities.FromX509Certificate(cert);
cms.MyAddSigner(rsa, certCopy, keyParameter, "1.2.840.113549.1.1.1", "2.16.840.1.101.3.4.2.1", AT, null);
ArrayList certList = new ArrayList();
certList.Add(certCopy);
Org.BouncyCastle.X509.Store.X509CollectionStoreParameters PP = new Org.BouncyCastle.X509.Store.X509CollectionStoreParameters(certList);
Org.BouncyCastle.X509.Store.IX509Store st1 = Org.BouncyCastle.X509.Store.X509StoreFactory.Create("CERTIFICATE/COLLECTION", PP);
cms.AddCertificates(st1);
FileInfo File__1 = new FileInfo(NomeFile);
CmsProcessableFile file__2 = new CmsProcessableFile(File__1);
CmsSignedData Firmato = cms.Generate(file__2, true);
byte[] Encoded = Firmato.GetEncoded();
RisFirma = "";
return Encoded;

That is the windows xp error

Help is much appreciated. Kind Regards

Answer 1

It looks like the SHA-256 hash or the OID of the SHA-256. Try and update XP to the latest service pack; XP is old , so it may not support all algorithms out of the box. The idea of creating signatures on XP machines should be avoided; you should not create security on a platform without support or bug fixes.

Answer 2

I solved the problem, it seems that the latest CSP doesn't work with windows xp, i tryed with another CSP and the function start to work again.

bye