DecryptMessage

// SECUR32.dll
#include <windows.h>

HRESULT DecryptMessage(
    SecHandle* phContext,
    SecBufferDesc* pMessage,
    DWORD MessageSeqNo,
    DWORD* pfQOP   // optional
);

<DllImport("SECUR32.dll", ExactSpelling:=True)>
Public Shared Function DecryptMessage(
    phContext As IntPtr,   ' SecHandle*
    pMessage As IntPtr,   ' SecBufferDesc*
    MessageSeqNo As UInteger,   ' DWORD
    pfQOP As IntPtr   ' DWORD* optional, out
) As Integer
End Function

' phContext : SecHandle*
' pMessage : SecBufferDesc*
' MessageSeqNo : DWORD
' pfQOP : DWORD* optional, out
Declare PtrSafe Function DecryptMessage Lib "secur32" ( _
    ByVal phContext As LongPtr, _
    ByVal pMessage As LongPtr, _
    ByVal MessageSeqNo As Long, _
    ByVal pfQOP As LongPtr) As Long
' VBA7前提(PtrSafe)。32bit Office では LongPtr→Long。Integer=16bit / Long=32bit / LongLong=64bit。

import ctypes
from ctypes import wintypes

DecryptMessage = ctypes.windll.secur32.DecryptMessage
DecryptMessage.restype = ctypes.c_int
DecryptMessage.argtypes = [
    ctypes.c_void_p,  # phContext : SecHandle*
    ctypes.c_void_p,  # pMessage : SecBufferDesc*
    wintypes.DWORD,  # MessageSeqNo : DWORD
    ctypes.POINTER(wintypes.DWORD),  # pfQOP : DWORD* optional, out
]

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('SECUR32.dll')
DecryptMessage = Fiddle::Function.new(
  lib['DecryptMessage'],
  [
    Fiddle::TYPE_VOIDP,  # phContext : SecHandle*
    Fiddle::TYPE_VOIDP,  # pMessage : SecBufferDesc*
    -Fiddle::TYPE_INT,  # MessageSeqNo : DWORD
    Fiddle::TYPE_VOIDP,  # pfQOP : DWORD* optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "secur32")]
extern "system" {
    fn DecryptMessage(
        phContext: *mut SecHandle,  // SecHandle*
        pMessage: *mut SecBufferDesc,  // SecBufferDesc*
        MessageSeqNo: u32,  // DWORD
        pfQOP: *mut u32  // DWORD* optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[DllImport("SECUR32.dll")]
public static extern int DecryptMessage(IntPtr phContext, IntPtr pMessage, uint MessageSeqNo, IntPtr pfQOP);
"@
$api = Add-Type -MemberDefinition $sig -Name 'SECUR32_DecryptMessage' -Namespace Win32 -PassThru
# $api::DecryptMessage(phContext, pMessage, MessageSeqNo, pfQOP)

#uselib "SECUR32.dll"
#func global DecryptMessage "DecryptMessage" sptr, sptr, sptr, sptr
; DecryptMessage varptr(phContext), varptr(pMessage), MessageSeqNo, varptr(pfQOP)   ; 戻り値は stat
; phContext : SecHandle* -> "sptr"
; pMessage : SecBufferDesc* -> "sptr"
; MessageSeqNo : DWORD -> "sptr"
; pfQOP : DWORD* optional, out -> "sptr"
; ※HSP3.7は #func のため戻り値はシステム変数 stat に格納されます。

#uselib "SECUR32.dll"
#cfunc global DecryptMessage "DecryptMessage" var, var, int, var
; res = DecryptMessage(phContext, pMessage, MessageSeqNo, pfQOP)
; phContext : SecHandle* -> "var"
; pMessage : SecBufferDesc* -> "var"
; MessageSeqNo : DWORD -> "int"
; pfQOP : DWORD* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

; HRESULT DecryptMessage(SecHandle* phContext, SecBufferDesc* pMessage, DWORD MessageSeqNo, DWORD* pfQOP)
#uselib "SECUR32.dll"
#cfunc global DecryptMessage "DecryptMessage" var, var, int, var
; res = DecryptMessage(phContext, pMessage, MessageSeqNo, pfQOP)
; phContext : SecHandle* -> "var"
; pMessage : SecBufferDesc* -> "var"
; MessageSeqNo : DWORD -> "int"
; pfQOP : DWORD* optional, out -> "var"
; ※出力/バッファ引数は var 方式(変数を直接渡す)。varptr 方式にも切替可。

import (
	"golang.org/x/sys/windows"
	"unsafe"
)

var (
	secur32 = windows.NewLazySystemDLL("SECUR32.dll")
	procDecryptMessage = secur32.NewProc("DecryptMessage")
)

// phContext (SecHandle*), pMessage (SecBufferDesc*), MessageSeqNo (DWORD), pfQOP (DWORD* optional, out)
r1, _, err := procDecryptMessage.Call(
	uintptr(phContext),
	uintptr(pMessage),
	uintptr(MessageSeqNo),
	uintptr(pfQOP),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // HRESULT

function DecryptMessage(
  phContext: Pointer;   // SecHandle*
  pMessage: Pointer;   // SecBufferDesc*
  MessageSeqNo: DWORD;   // DWORD
  pfQOP: Pointer   // DWORD* optional, out
): Integer; stdcall;
  external 'SECUR32.dll' name 'DecryptMessage';

result := DllCall("SECUR32\DecryptMessage"
    , "Ptr", phContext   ; SecHandle*
    , "Ptr", pMessage   ; SecBufferDesc*
    , "UInt", MessageSeqNo   ; DWORD
    , "Ptr", pfQOP   ; DWORD* optional, out
    , "Int")   ; return: HRESULT

●DecryptMessage(phContext, pMessage, MessageSeqNo, pfQOP) = DLL("SECUR32.dll", "int DecryptMessage(void*, void*, dword, void*)")
# 呼び出し: DecryptMessage(phContext, pMessage, MessageSeqNo, pfQOP)
# phContext : SecHandle* -> "void*"
# pMessage : SecBufferDesc* -> "void*"
# MessageSeqNo : DWORD -> "dword"
# pfQOP : DWORD* optional, out -> "void*"
# なでしこ1は32bit・ANSI(Shift_JIS)。文字列=char*(ANSI)、ポインタ/ハンドル=void*(4byte)。