private Exception TryExecuteDecryptAgree(ref CMSG_CTRL_KEY_AGREE_DECRYPT_PARA decryptPara)
{
if (!Interop.Crypt32.CryptMsgControl(_hCryptMsg, 0, MsgControlType.CMSG_CTRL_KEY_AGREE_DECRYPT, ref decryptPara))
{
ErrorCode errorCode = (ErrorCode)(Marshal.GetHRForLastWin32Error());
return(errorCode.ToCryptographicException());
}
return(null);
}
private Exception TryDecryptAgree(KeyAgreeRecipientInfo keyAgreeRecipientInfo, SafeProvOrNCryptKeyHandle hKey, CryptKeySpec keySpec, X509Certificate2Collection originatorCerts, X509Certificate2Collection extraStore)
{
unsafe
{
KeyAgreeRecipientInfoPalWindows pal = (KeyAgreeRecipientInfoPalWindows)(keyAgreeRecipientInfo.Pal);
return(pal.WithCmsgCmsRecipientInfo <Exception>(
delegate(CMSG_KEY_AGREE_RECIPIENT_INFO * pKeyAgreeRecipientInfo)
{
CMSG_CTRL_KEY_AGREE_DECRYPT_PARA decryptPara = default(CMSG_CTRL_KEY_AGREE_DECRYPT_PARA);
decryptPara.cbSize = Marshal.SizeOf <CMSG_CTRL_KEY_AGREE_DECRYPT_PARA>();
decryptPara.hProv = hKey;
decryptPara.dwKeySpec = keySpec;
decryptPara.pKeyAgree = pKeyAgreeRecipientInfo;
decryptPara.dwRecipientIndex = pal.Index;
decryptPara.dwRecipientEncryptedKeyIndex = pal.SubIndex;
CMsgKeyAgreeOriginatorChoice originatorChoice = pKeyAgreeRecipientInfo->dwOriginatorChoice;
switch (originatorChoice)
{
case CMsgKeyAgreeOriginatorChoice.CMSG_KEY_AGREE_ORIGINATOR_CERT:
{
X509Certificate2Collection candidateCerts = new X509Certificate2Collection();
candidateCerts.AddRange(Helpers.GetStoreCertificates(StoreName.AddressBook, StoreLocation.CurrentUser, openExistingOnly: true));
candidateCerts.AddRange(Helpers.GetStoreCertificates(StoreName.AddressBook, StoreLocation.LocalMachine, openExistingOnly: true));
candidateCerts.AddRange(originatorCerts);
candidateCerts.AddRange(extraStore);
SubjectIdentifier originatorId = pKeyAgreeRecipientInfo->OriginatorCertId.ToSubjectIdentifier();
using (X509Certificate2 originatorCert = candidateCerts.TryFindMatchingCertificate(originatorId))
{
if (originatorCert == null)
{
return ErrorCode.CRYPT_E_NOT_FOUND.ToCryptographicException();
}
using (SafeCertContextHandle hCertContext = originatorCert.CreateCertContextHandle())
{
CERT_CONTEXT *pOriginatorCertContext = hCertContext.DangerousGetCertContext();
decryptPara.OriginatorPublicKey = pOriginatorCertContext->pCertInfo->SubjectPublicKeyInfo.PublicKey;
// Do not factor this call out of the switch statement as leaving this "using" block will free up
// native memory that decryptPara points to.
return TryExecuteDecryptAgree(ref decryptPara);
}
}
}
case CMsgKeyAgreeOriginatorChoice.CMSG_KEY_AGREE_ORIGINATOR_PUBLIC_KEY:
{
decryptPara.OriginatorPublicKey = pKeyAgreeRecipientInfo->OriginatorPublicKeyInfo.PublicKey;
return TryExecuteDecryptAgree(ref decryptPara);
}
default:
return new CryptographicException(SR.Format(SR.Cryptography_Cms_Invalid_Originator_Identifier_Choice, originatorChoice));
}
}));
}
}
internal static partial bool CryptMsgControl(
SafeCryptMsgHandle hCryptMsg,
int dwFlags,
MsgControlType dwCtrlType,
ref CMSG_CTRL_KEY_AGREE_DECRYPT_PARA pvCtrlPara);
private Exception TryExecuteDecryptAgree(ref CMSG_CTRL_KEY_AGREE_DECRYPT_PARA decryptPara)
{
if (!Interop.Crypt32.CryptMsgControl(_hCryptMsg, 0, MsgControlType.CMSG_CTRL_KEY_AGREE_DECRYPT, ref decryptPara))
{
ErrorCode errorCode = (ErrorCode)(Marshal.GetHRForLastWin32Error());
return errorCode.ToCryptographicException();
}
return null;
}
