private unsafe void CounterSign(CmsSigner signer)
{
// Sanity check.
Debug.Assert(signer != null);
//
CspParameters parameters = new CspParameters();
if (X509Utils.GetPrivateKeyInfo(X509Utils.GetCertContext(signer.Certificate), ref parameters) == false)
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
KeyContainerPermission kp = new KeyContainerPermission(KeyContainerPermissionFlags.NoFlags);
KeyContainerPermissionAccessEntry entry = new KeyContainerPermissionAccessEntry(parameters, KeyContainerPermissionFlags.Open | KeyContainerPermissionFlags.Sign);
kp.AccessEntries.Add(entry);
kp.Demand();
// Get the signer's index.
uint index = (uint)PkcsUtils.GetSignerIndex(m_signedCms.GetCryptMsgHandle(), this, 0);
// Create CMSG_SIGNER_ENCODE_INFO structure.
SafeLocalAllocHandle pSignerEncodeInfo = CAPI.LocalAlloc(CAPI.LPTR, new IntPtr(Marshal.SizeOf(typeof(CAPI.CMSG_SIGNER_ENCODE_INFO))));
CAPI.CMSG_SIGNER_ENCODE_INFO signerEncodeInfo = PkcsUtils.CreateSignerEncodeInfo(signer);
try {
// Marshal to unmanaged memory.
Marshal.StructureToPtr(signerEncodeInfo, pSignerEncodeInfo.DangerousGetHandle(), false);
// Counter sign.
if (!CAPI.CryptMsgCountersign(m_signedCms.GetCryptMsgHandle(),
index,
1,
pSignerEncodeInfo.DangerousGetHandle()))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
// CAPI requires that the messge be re-encoded if any unauthenticated
// attribute has been added. So, let's re-open it to decode to work
// around this limitation.
m_signedCms.ReopenToDecode();
}
finally {
Marshal.DestroyStructure(pSignerEncodeInfo.DangerousGetHandle(), typeof(CAPI.CMSG_SIGNER_ENCODE_INFO));
pSignerEncodeInfo.Dispose();
// and don't forget to dispose of resources allocated for the structure.
signerEncodeInfo.Dispose();
}
// Finally, add certs to bag of certs.
PkcsUtils.AddCertsToMessage(m_signedCms.GetCryptMsgHandle(), m_signedCms.Certificates, PkcsUtils.CreateBagOfCertificates(signer));
return;
}
public void ComputeSignature(CmsSigner signer, bool silent)
{
if (signer == null)
{
throw new ArgumentNullException("signer");
}
if (ContentInfo.Content.Length == 0)
{
throw new CryptographicException(SecurityResources.GetResourceString("Cryptography_Cms_Sign_Empty_Content"));
}
if (SubjectIdentifierType.NoSignature == signer.SignerIdentifierType)
{
if (m_safeCryptMsgHandle != null && !m_safeCryptMsgHandle.IsInvalid)
{
throw new CryptographicException(SecurityResources.GetResourceString("Cryptography_Cms_Sign_No_Signature_First_Signer"));
}
// First signer.
Sign(signer, silent);
return;
}
if (signer.Certificate == null)
{
if (silent)
{
throw new InvalidOperationException(SecurityResources.GetResourceString("Cryptography_Cms_RecipientCertificateNotFound"));
}
else
{
signer.Certificate = PkcsUtils.SelectSignerCertificate();
}
}
if (!signer.Certificate.HasPrivateKey)
{
throw new CryptographicException(CAPI.NTE_NO_KEY);
}
//
CspParameters parameters = new CspParameters();
if (X509Utils.GetPrivateKeyInfo(X509Utils.GetCertContext(signer.Certificate), ref parameters))
{
KeyContainerPermission kp = new KeyContainerPermission(KeyContainerPermissionFlags.NoFlags);
KeyContainerPermissionAccessEntry entry = new KeyContainerPermissionAccessEntry(parameters, KeyContainerPermissionFlags.Open | KeyContainerPermissionFlags.Sign);
kp.AccessEntries.Add(entry);
kp.Demand();
}
if (m_safeCryptMsgHandle == null || m_safeCryptMsgHandle.IsInvalid)
{
// First signer.
Sign(signer, silent);
}
else
{
// Co-signing.
CoSign(signer, silent);
}
}
