internal static extern unsafe SafeCryptMsgHandle CryptMsgOpenToEncode(
MsgEncodingType dwMsgEncodingType,
int dwFlags,
CryptMsgType dwMsgType,
CMSG_ENVELOPED_ENCODE_INFO *pvMsgEncodeInfo,
[MarshalAs(UnmanagedType.LPStr)] string pszInnerContentObjID,
IntPtr pStreamInfo);
internal static extern bool CryptMsgGetParam(
#endif
SafeCryptMsgHandle hCryptMsg,
CryptMsgParamType dwParamType,
int dwIndex,
out CryptMsgType pvData,
ref int pcbData);
internal static DecryptorPalWindows Decode(
ReadOnlySpan <byte> encodedMessage,
out int version,
out ContentInfo contentInfo,
out AlgorithmIdentifier contentEncryptionAlgorithm,
out X509Certificate2Collection originatorCerts,
out CryptographicAttributeObjectCollection unprotectedAttributes
)
{
SafeCryptMsgHandle hCryptMsg = Interop.Crypt32.CryptMsgOpenToDecode(MsgEncodingType.All, 0, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
if (hCryptMsg == null || hCryptMsg.IsInvalid)
{
throw Marshal.GetLastWin32Error().ToCryptographicException();
}
if (!Interop.Crypt32.CryptMsgUpdate(
hCryptMsg,
ref MemoryMarshal.GetReference(encodedMessage),
encodedMessage.Length,
fFinal: true))
{
throw Marshal.GetLastWin32Error().ToCryptographicException();
}
CryptMsgType cryptMsgType = hCryptMsg.GetMessageType();
if (cryptMsgType != CryptMsgType.CMSG_ENVELOPED)
{
throw ErrorCode.CRYPT_E_INVALID_MSG_TYPE.ToCryptographicException();
}
version = hCryptMsg.GetVersion();
contentInfo = hCryptMsg.GetContentInfo();
AlgorithmIdentifierAsn contentEncryptionAlgorithmAsn;
using (SafeHandle sh = hCryptMsg.GetMsgParamAsMemory(CryptMsgParamType.CMSG_ENVELOPE_ALGORITHM_PARAM))
{
unsafe
{
CRYPT_ALGORITHM_IDENTIFIER *pCryptAlgorithmIdentifier = (CRYPT_ALGORITHM_IDENTIFIER *)(sh.DangerousGetHandle());
contentEncryptionAlgorithm = (*pCryptAlgorithmIdentifier).ToAlgorithmIdentifier();
contentEncryptionAlgorithmAsn.Algorithm = contentEncryptionAlgorithm.Oid.Value !;
contentEncryptionAlgorithmAsn.Parameters = (*pCryptAlgorithmIdentifier).Parameters.ToByteArray();
}
}
originatorCerts = hCryptMsg.GetOriginatorCerts();
unprotectedAttributes = hCryptMsg.GetUnprotectedAttributes();
RecipientInfoCollection recipientInfos = CreateRecipientInfos(hCryptMsg);
return(new DecryptorPalWindows(hCryptMsg, recipientInfos, contentEncryptionAlgorithmAsn));
}
public sealed override Oid GetEncodedMessageType(byte[] encodedMessage)
{
using (SafeCryptMsgHandle hCryptMsg = Interop.Crypt32.CryptMsgOpenToDecode(MsgEncodingType.All, 0, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero))
{
if (hCryptMsg == null || hCryptMsg.IsInvalid)
{
throw Marshal.GetLastWin32Error().ToCryptographicException();
}
if (!Interop.Crypt32.CryptMsgUpdate(hCryptMsg, encodedMessage, encodedMessage.Length, fFinal: true))
{
throw Marshal.GetLastWin32Error().ToCryptographicException();
}
int msgTypeAsInt;
int cbSize = sizeof(int);
if (!Interop.Crypt32.CryptMsgGetParam(hCryptMsg, CryptMsgParamType.CMSG_TYPE_PARAM, 0, out msgTypeAsInt, ref cbSize))
{
throw Marshal.GetLastWin32Error().ToCryptographicException();
}
CryptMsgType msgType = (CryptMsgType)msgTypeAsInt;
switch (msgType)
{
case CryptMsgType.CMSG_DATA:
return(Oid.FromOidValue(Oids.Pkcs7Data, OidGroup.ExtensionOrAttribute));
case CryptMsgType.CMSG_SIGNED:
return(Oid.FromOidValue(Oids.Pkcs7Signed, OidGroup.ExtensionOrAttribute));
case CryptMsgType.CMSG_ENVELOPED:
return(Oid.FromOidValue(Oids.Pkcs7Enveloped, OidGroup.ExtensionOrAttribute));
case CryptMsgType.CMSG_SIGNED_AND_ENVELOPED:
return(Oid.FromOidValue(Oids.Pkcs7SignedEnveloped, OidGroup.ExtensionOrAttribute));
case CryptMsgType.CMSG_HASHED:
return(Oid.FromOidValue(Oids.Pkcs7Hashed, OidGroup.ExtensionOrAttribute));
case CryptMsgType.CMSG_ENCRYPTED:
return(Oid.FromOidValue(Oids.Pkcs7Encrypted, OidGroup.ExtensionOrAttribute));
default:
throw ErrorCode.CRYPT_E_INVALID_MSG_TYPE.ToCryptographicException();
}
}
}
internal static extern bool CryptMsgGetParam(SafeCryptMsgHandle hCryptMsg, CryptMsgParamType dwParamType, int dwIndex, out CryptMsgType pvData, [In, Out] ref int pcbData);
internal static unsafe extern SafeCryptMsgHandle CryptMsgOpenToEncode(MsgEncodingType dwMsgEncodingType, int dwFlags, CryptMsgType dwMsgType, CMSG_ENVELOPED_ENCODE_INFO* pvMsgEncodeInfo, [MarshalAs(UnmanagedType.LPStr)] string pszInnerContentObjID, IntPtr pStreamInfo);
internal static partial bool CryptMsgGetParam(
SafeCryptMsgHandle hCryptMsg,
CryptMsgParamType dwParamType,
int dwIndex,
out CryptMsgType pvData,
ref int pcbData);
