public void Decode (byte[] encodedMessage)
{
if (encodedMessage == null)
throw new ArgumentNullException ("encodedMessage");
PKCS7.ContentInfo ci = new PKCS7.ContentInfo (encodedMessage);
if (ci.ContentType != PKCS7.Oid.envelopedData)
throw new Exception ("");
PKCS7.EnvelopedData ed = new PKCS7.EnvelopedData (ci.Content);
Oid oid = new Oid (ed.ContentInfo.ContentType);
_content = new ContentInfo (oid, new byte [0]); //ed.ContentInfo.Content.Value);
foreach (PKCS7.RecipientInfo ri in ed.RecipientInfos) {
Oid o = new Oid (ri.Oid);
AlgorithmIdentifier ai = new AlgorithmIdentifier (o);
SubjectIdentifier si = null;
if (ri.SubjectKeyIdentifier != null) {
si = new SubjectIdentifier (SubjectIdentifierType.SubjectKeyIdentifier, ri.SubjectKeyIdentifier);
}
else if ((ri.Issuer != null) && (ri.Serial != null)) {
X509IssuerSerial xis = GetIssuerSerial (ri.Issuer, ri.Serial);
si = new SubjectIdentifier (SubjectIdentifierType.IssuerAndSerialNumber, (object)xis);
}
KeyTransRecipientInfo _keyTrans = new KeyTransRecipientInfo (ri.Key, ai, si, ri.Version);
_recipients.Add (_keyTrans);
}
// TODO - Certificates
// TODO - UnprotectedAttributes
_version = ed.Version;
}
private Exception TryDecryptTrans(KeyTransRecipientInfo recipientInfo, SafeProvOrNCryptKeyHandle hKey, CryptKeySpec keySpec)
{
KeyTransRecipientInfoPalWindows pal = (KeyTransRecipientInfoPalWindows)(recipientInfo.Pal);
CMSG_CTRL_DECRYPT_PARA decryptPara;
decryptPara.cbSize = Marshal.SizeOf<CMSG_CTRL_DECRYPT_PARA>();
decryptPara.hKey = hKey;
decryptPara.dwKeySpec = keySpec;
decryptPara.dwRecipientIndex = pal.Index;
bool success = Interop.Crypt32.CryptMsgControl(_hCryptMsg, 0, MsgControlType.CMSG_CTRL_DECRYPT, ref decryptPara);
if (!success)
return Marshal.GetHRForLastWin32Error().ToCryptographicException();
return null;
}
