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CryptDecryptMessage

関数

暗号化メッセージを復号して元データを取得する。

DLLCRYPT32.dll呼出規約winapiSetLastErrorあり対応OSWindows XP 以降

シグネチャ

// CRYPT32.dll
#include <windows.h>

BOOL CryptDecryptMessage(
    CRYPT_DECRYPT_MESSAGE_PARA* pDecryptPara,
    const BYTE* pbEncryptedBlob,
    DWORD cbEncryptedBlob,
    BYTE* pbDecrypted,   // optional
    DWORD* pcbDecrypted,   // optional
    CERT_CONTEXT** ppXchgCert   // optional
);

パラメーター

名前	型	方向
pDecryptPara	CRYPT_DECRYPT_MESSAGE_PARA*	in
pbEncryptedBlob	BYTE*	in
cbEncryptedBlob	DWORD	in
pbDecrypted	BYTE*	outoptional
pcbDecrypted	DWORD*	inoutoptional
ppXchgCert	CERT_CONTEXT**	outoptional

戻り値の型: BOOL

各言語での呼び出し定義

// CRYPT32.dll
#include <windows.h>

BOOL CryptDecryptMessage(
    CRYPT_DECRYPT_MESSAGE_PARA* pDecryptPara,
    const BYTE* pbEncryptedBlob,
    DWORD cbEncryptedBlob,
    BYTE* pbDecrypted,   // optional
    DWORD* pcbDecrypted,   // optional
    CERT_CONTEXT** ppXchgCert   // optional
);

[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("CRYPT32.dll", SetLastError = true, ExactSpelling = true)]
static extern bool CryptDecryptMessage(
    IntPtr pDecryptPara,   // CRYPT_DECRYPT_MESSAGE_PARA*
    IntPtr pbEncryptedBlob,   // BYTE*
    uint cbEncryptedBlob,   // DWORD
    IntPtr pbDecrypted,   // BYTE* optional, out
    IntPtr pcbDecrypted,   // DWORD* optional, in/out
    IntPtr ppXchgCert   // CERT_CONTEXT** optional, out
);

<DllImport("CRYPT32.dll", SetLastError:=True, ExactSpelling:=True)>
Public Shared Function CryptDecryptMessage(
    pDecryptPara As IntPtr,   ' CRYPT_DECRYPT_MESSAGE_PARA*
    pbEncryptedBlob As IntPtr,   ' BYTE*
    cbEncryptedBlob As UInteger,   ' DWORD
    pbDecrypted As IntPtr,   ' BYTE* optional, out
    pcbDecrypted As IntPtr,   ' DWORD* optional, in/out
    ppXchgCert As IntPtr   ' CERT_CONTEXT** optional, out
) As Boolean
End Function

' pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA*
' pbEncryptedBlob : BYTE*
' cbEncryptedBlob : DWORD
' pbDecrypted : BYTE* optional, out
' pcbDecrypted : DWORD* optional, in/out
' ppXchgCert : CERT_CONTEXT** optional, out
Declare PtrSafe Function CryptDecryptMessage Lib "crypt32" ( _
    ByVal pDecryptPara As LongPtr, _
    ByVal pbEncryptedBlob As LongPtr, _
    ByVal cbEncryptedBlob As Long, _
    ByVal pbDecrypted As LongPtr, _
    ByVal pcbDecrypted As LongPtr, _
    ByVal ppXchgCert 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

CryptDecryptMessage = ctypes.windll.crypt32.CryptDecryptMessage
CryptDecryptMessage.restype = wintypes.BOOL
CryptDecryptMessage.argtypes = [
    ctypes.c_void_p,  # pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA*
    ctypes.POINTER(ctypes.c_ubyte),  # pbEncryptedBlob : BYTE*
    wintypes.DWORD,  # cbEncryptedBlob : DWORD
    ctypes.POINTER(ctypes.c_ubyte),  # pbDecrypted : BYTE* optional, out
    ctypes.POINTER(wintypes.DWORD),  # pcbDecrypted : DWORD* optional, in/out
    ctypes.c_void_p,  # ppXchgCert : CERT_CONTEXT** optional, out
]
# GetLastError: use ctypes.GetLastError() (or ctypes.WinDLL(use_last_error=True))

require 'fiddle'
require 'fiddle/import'

lib = Fiddle.dlopen('CRYPT32.dll')
CryptDecryptMessage = Fiddle::Function.new(
  lib['CryptDecryptMessage'],
  [
    Fiddle::TYPE_VOIDP,  # pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA*
    Fiddle::TYPE_VOIDP,  # pbEncryptedBlob : BYTE*
    -Fiddle::TYPE_INT,  # cbEncryptedBlob : DWORD
    Fiddle::TYPE_VOIDP,  # pbDecrypted : BYTE* optional, out
    Fiddle::TYPE_VOIDP,  # pcbDecrypted : DWORD* optional, in/out
    Fiddle::TYPE_VOIDP,  # ppXchgCert : CERT_CONTEXT** optional, out
  ],
  Fiddle::TYPE_INT)

#[link(name = "crypt32")]
extern "system" {
    fn CryptDecryptMessage(
        pDecryptPara: *mut CRYPT_DECRYPT_MESSAGE_PARA,  // CRYPT_DECRYPT_MESSAGE_PARA*
        pbEncryptedBlob: *const u8,  // BYTE*
        cbEncryptedBlob: u32,  // DWORD
        pbDecrypted: *mut u8,  // BYTE* optional, out
        pcbDecrypted: *mut u32,  // DWORD* optional, in/out
        ppXchgCert: *mut *mut CERT_CONTEXT  // CERT_CONTEXT** optional, out
    ) -> i32;
}
// crates: windows-sys provides ready-made bindings for this API.

$sig = @"
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("CRYPT32.dll", SetLastError = true)]
public static extern bool CryptDecryptMessage(IntPtr pDecryptPara, IntPtr pbEncryptedBlob, uint cbEncryptedBlob, IntPtr pbDecrypted, IntPtr pcbDecrypted, IntPtr ppXchgCert);
"@
$api = Add-Type -MemberDefinition $sig -Name 'CRYPT32_CryptDecryptMessage' -Namespace Win32 -PassThru
# $api::CryptDecryptMessage(pDecryptPara, pbEncryptedBlob, cbEncryptedBlob, pbDecrypted, pcbDecrypted, ppXchgCert)

#uselib "CRYPT32.dll"
#func global CryptDecryptMessage "CryptDecryptMessage" sptr, sptr, sptr, sptr, sptr, sptr
; CryptDecryptMessage varptr(pDecryptPara), varptr(pbEncryptedBlob), cbEncryptedBlob, varptr(pbDecrypted), varptr(pcbDecrypted), varptr(ppXchgCert)   ; 戻り値は stat
; pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "sptr"
; pbEncryptedBlob : BYTE* -> "sptr"
; cbEncryptedBlob : DWORD -> "sptr"
; pbDecrypted : BYTE* optional, out -> "sptr"
; pcbDecrypted : DWORD* optional, in/out -> "sptr"
; ppXchgCert : CERT_CONTEXT** 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。

出力引数:

#uselib "CRYPT32.dll"
#cfunc global CryptDecryptMessage "CryptDecryptMessage" var, var, int, var, var, var
; res = CryptDecryptMessage(pDecryptPara, pbEncryptedBlob, cbEncryptedBlob, pbDecrypted, pcbDecrypted, ppXchgCert)
; pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "var"
; pbEncryptedBlob : BYTE* -> "var"
; cbEncryptedBlob : DWORD -> "int"
; pbDecrypted : BYTE* optional, out -> "var"
; pcbDecrypted : DWORD* optional, in/out -> "var"
; ppXchgCert : CERT_CONTEXT** 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。#uselib "CRYPT32.dll"
#cfunc global CryptDecryptMessage "CryptDecryptMessage" sptr, sptr, int, sptr, sptr, sptr
; res = CryptDecryptMessage(varptr(pDecryptPara), varptr(pbEncryptedBlob), cbEncryptedBlob, varptr(pbDecrypted), varptr(pcbDecrypted), varptr(ppXchgCert))
; pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "sptr"
; pbEncryptedBlob : BYTE* -> "sptr"
; cbEncryptedBlob : DWORD -> "int"
; pbDecrypted : BYTE* optional, out -> "sptr"
; pcbDecrypted : DWORD* optional, in/out -> "sptr"
; ppXchgCert : CERT_CONTEXT** optional, out -> "sptr"
; ※出力/バッファ引数はポインタ方式(token=sptr / 呼び出しは varptr(変数))。

出力引数:

; BOOL CryptDecryptMessage(CRYPT_DECRYPT_MESSAGE_PARA* pDecryptPara, BYTE* pbEncryptedBlob, DWORD cbEncryptedBlob, BYTE* pbDecrypted, DWORD* pcbDecrypted, CERT_CONTEXT** ppXchgCert)
#uselib "CRYPT32.dll"
#cfunc global CryptDecryptMessage "CryptDecryptMessage" var, var, int, var, var, var
; res = CryptDecryptMessage(pDecryptPara, pbEncryptedBlob, cbEncryptedBlob, pbDecrypted, pcbDecrypted, ppXchgCert)
; pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "var"
; pbEncryptedBlob : BYTE* -> "var"
; cbEncryptedBlob : DWORD -> "int"
; pbDecrypted : BYTE* optional, out -> "var"
; pcbDecrypted : DWORD* optional, in/out -> "var"
; ppXchgCert : CERT_CONTEXT** 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。; BOOL CryptDecryptMessage(CRYPT_DECRYPT_MESSAGE_PARA* pDecryptPara, BYTE* pbEncryptedBlob, DWORD cbEncryptedBlob, BYTE* pbDecrypted, DWORD* pcbDecrypted, CERT_CONTEXT** ppXchgCert)
#uselib "CRYPT32.dll"
#cfunc global CryptDecryptMessage "CryptDecryptMessage" intptr, intptr, int, intptr, intptr, intptr
; res = CryptDecryptMessage(varptr(pDecryptPara), varptr(pbEncryptedBlob), cbEncryptedBlob, varptr(pbDecrypted), varptr(pcbDecrypted), varptr(ppXchgCert))
; pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "intptr"
; pbEncryptedBlob : BYTE* -> "intptr"
; cbEncryptedBlob : DWORD -> "int"
; pbDecrypted : BYTE* optional, out -> "intptr"
; pcbDecrypted : DWORD* optional, in/out -> "intptr"
; ppXchgCert : CERT_CONTEXT** optional, out -> "intptr"
; ※出力/バッファ引数はポインタ方式(token=intptr / 呼び出しは varptr(変数))。

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

var (
	crypt32 = windows.NewLazySystemDLL("CRYPT32.dll")
	procCryptDecryptMessage = crypt32.NewProc("CryptDecryptMessage")
)

// pDecryptPara (CRYPT_DECRYPT_MESSAGE_PARA*), pbEncryptedBlob (BYTE*), cbEncryptedBlob (DWORD), pbDecrypted (BYTE* optional, out), pcbDecrypted (DWORD* optional, in/out), ppXchgCert (CERT_CONTEXT** optional, out)
r1, _, err := procCryptDecryptMessage.Call(
	uintptr(pDecryptPara),
	uintptr(pbEncryptedBlob),
	uintptr(cbEncryptedBlob),
	uintptr(pbDecrypted),
	uintptr(pcbDecrypted),
	uintptr(ppXchgCert),
)
_ = err  // syscall.Errno (valid when the call sets last-error)
_ = r1   // BOOL

function CryptDecryptMessage(
  pDecryptPara: Pointer;   // CRYPT_DECRYPT_MESSAGE_PARA*
  pbEncryptedBlob: Pointer;   // BYTE*
  cbEncryptedBlob: DWORD;   // DWORD
  pbDecrypted: Pointer;   // BYTE* optional, out
  pcbDecrypted: Pointer;   // DWORD* optional, in/out
  ppXchgCert: Pointer   // CERT_CONTEXT** optional, out
): BOOL; stdcall;
  external 'CRYPT32.dll' name 'CryptDecryptMessage';

result := DllCall("CRYPT32\CryptDecryptMessage"
    , "Ptr", pDecryptPara   ; CRYPT_DECRYPT_MESSAGE_PARA*
    , "Ptr", pbEncryptedBlob   ; BYTE*
    , "UInt", cbEncryptedBlob   ; DWORD
    , "Ptr", pbDecrypted   ; BYTE* optional, out
    , "Ptr", pcbDecrypted   ; DWORD* optional, in/out
    , "Ptr", ppXchgCert   ; CERT_CONTEXT** optional, out
    , "Int")   ; return: BOOL

●CryptDecryptMessage(pDecryptPara, pbEncryptedBlob, cbEncryptedBlob, pbDecrypted, pcbDecrypted, ppXchgCert) = DLL("CRYPT32.dll", "bool CryptDecryptMessage(void*, void*, dword, void*, void*, void*)")
# 呼び出し: CryptDecryptMessage(pDecryptPara, pbEncryptedBlob, cbEncryptedBlob, pbDecrypted, pcbDecrypted, ppXchgCert)
# pDecryptPara : CRYPT_DECRYPT_MESSAGE_PARA* -> "void*"
# pbEncryptedBlob : BYTE* -> "void*"
# cbEncryptedBlob : DWORD -> "dword"
# pbDecrypted : BYTE* optional, out -> "void*"
# pcbDecrypted : DWORD* optional, in/out -> "void*"
# ppXchgCert : CERT_CONTEXT** 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)。