function GetNextCRLPublish(Context: PCCRL_CONTEXT): TDateTime;
const
  szOID_CRL_NEXT_PUBLISH   = '1.3.6.1.4.1.311.21.4';
var
  pExtension: PCERT_EXTENSION;
  cbStructInfo: DWORD;
  pvStructInfo: PVOID;
  FileTime: PFileTime;
begin
  pExtension := CertFindExtension(szOID_CRL_NEXT_PUBLISH, Context^.pCrlInfo^.cExtension, Context^.pCrlInfo^.rgExtension);
  if Assigned(pExtension) and Win32Check(CryptDecodeObject(X509_ASN_ENCODING or PKCS_7_ASN_ENCODING,
    PKCS_UTC_TIME, pExtension^.Value.pbData, pExtension^.Value.cbData, CRYPT_DECODE_NOCOPY_FLAG, nil, @cbStructInfo)) then
  begin
    GetMem(pvStructInfo, cbStructInfo);
    try
      CryptDecodeObject(X509_ASN_ENCODING or PKCS_7_ASN_ENCODING, PKCS_UTC_TIME,
        pExtension^.Value.pbData, pExtension^.Value.cbData, 0, pvStructInfo, @cbStructInfo);
      FileTime := PFileTime(pvStructInfo);
      Result := DecodeFileTime(FileTime^);
    finally
      FreeMem(pvStructInfo);
    end;
  end
  else begin
    raise Exception.CreateFmt('Ошибка: %d', [GetLastError]);
  end;
end;

{ Преобразуем TFileTime в TDateTime }
function DecodeFileTime(FileTime : TFileTime): TDateTime;
var
  SystemTime : TSystemTime;
  ModifiedTime : TFileTime;
begin
  FileTimeToLocalFileTime( FileTime, ModifiedTime );
  FileTimeToSystemTime( ModifiedTime, SystemTime );
  Result := SystemTimeToDateTime( SystemTime );
end;