BowTiedGnome Posts

BowTiedGnome

•Created by BowTiedGnome on 8/11/2024 in #help

FFI on windows and handles

I keep hitting an issue of getting a windows error code of 6, which is invalid handle on windows. Are there any extra steps that I'm missing that I need to do for invoking windows APIs with deno FFI that is maybe undocumented?. I can get this to work in other languages, but FFI/interop uses different types. so its not a 1:1 translation.
code is trying to determine if process is elevated/privileged. the following should be run with deno run -A --unstable-ffi ./main.ts will have to split over multiple posts due to discord limits

/**
https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess
HANDLE GetCurrentProcess();

https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-openprocesstoken
BOOL GetTokenInformation(
  [in]            HANDLE                  TokenHandle,
  [in]            TOKEN_INFORMATION_CLASS TokenInformationClass,
  [out, optional] LPVOID                  TokenInformation,
  [in]            DWORD                   TokenInformationLength,
  [out]           PDWORD                  ReturnLength
);


https://learn.microsoft.com/en-us/windows/win32/api/securitybaseapi/nf-securitybaseapi-gettokeninformation
BOOL OpenProcessToken(
  [in]  HANDLE  ProcessHandle,
  [in]  DWORD   DesiredAccess,
  [out] PHANDLE TokenHandle
);
 */


const kernel32 = Deno.dlopen("kernel32.dll", {
    GetCurrentProcess: { parameters: [], result: "pointer" },
    CloseHandle: { parameters: ["pointer"], result: "i32" },
    GetLastError: { parameters: [], result: "i32" }
});
    
const advapi32 = Deno.dlopen("advapi32.dll", {
    OpenProcessToken: {
        parameters: ["pointer", "i32", "pointer"],
        result: "bool",
    },
    GetTokenInformation: {
        parameters: ["pointer", "u32", "buffer", "u32", "buffer"],
        result: "bool",
    },
});

/**
https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-getcurrentprocess
HANDLE GetCurrentProcess();

https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-openprocesstoken
BOOL GetTokenInformation(
  [in]            HANDLE                  TokenHandle,
  [in]            TOKEN_INFORMATION_CLASS TokenInformationClass,
  [out, optional] LPVOID                  TokenInformation,
  [in]            DWORD                   TokenInformationLength,
  [out]           PDWORD                  ReturnLength
);


https://learn.microsoft.com/en-us/windows/win32/api/securitybaseapi/nf-securitybaseapi-gettokeninformation
BOOL OpenProcessToken(
  [in]  HANDLE  ProcessHandle,
  [in]  DWORD   DesiredAccess,
  [out] PHANDLE TokenHandle
);
 */


const kernel32 = Deno.dlopen("kernel32.dll", {
    GetCurrentProcess: { parameters: [], result: "pointer" },
    CloseHandle: { parameters: ["pointer"], result: "i32" },
    GetLastError: { parameters: [], result: "i32" }
});
    
const advapi32 = Deno.dlopen("advapi32.dll", {
    OpenProcessToken: {
        parameters: ["pointer", "i32", "pointer"],
        result: "bool",
    },
    GetTokenInformation: {
        parameters: ["pointer", "u32", "buffer", "u32", "buffer"],
        result: "bool",
    },
});

4 replies