System.Data.SQLite

#ifdef SQLITE_HAS_CODEC
  void sqlite3pager_free_codecarg(void *pArg);
#endif

#include "src/pager.c"

#ifndef SQLITE_OMIT_DISKIO
#ifdef SQLITE_HAS_CODEC

#include <windows.h>
#include <wincrypt.h>





typedef struct _CRYPTBLOCK
{
  HCRYPTKEY hReadKey;     // Key used to read from the database and write to the journal
  HCRYPTKEY hWriteKey;    // Key used to write to the database
  DWORD     dwPageSize;   // Size of pages
  LPVOID    pvCrypt;      // A buffer for encrypting/decrypting (if necessary)
  DWORD     dwCryptSize;  // Equal to or greater than dwPageSize.  If larger, pvCrypt is valid and this is its size
} CRYPTBLOCK, *LPCRYPTBLOCK;

HCRYPTPROV g_hProvider = 0; // Global instance of the cryptographic provider

#define SQLITECRYPTERROR_PROVIDER "Cryptographic provider not available"

// Needed for re-keying
static void * sqlite3pager_get_codecarg(Pager *pPager)
{
  return (pPager->xCodec) ? pPager->pCodecArg: NULL;
}

  {
    LPCRYPTBLOCK pBlock = CreateCryptBlock(hKey, sqlite3BtreePager(db->aDb[nDb].pBt), NULL);
    sqlite3pager_set_codec(sqlite3BtreePager(db->aDb[nDb].pBt), sqlite3Codec, pBlock);
    rc = SQLITE_OK;
  }
  return rc;
}

void sqlite3pager_free_codecarg(void *pArg)
{
  LPCRYPTBLOCK pBlock = (LPCRYPTBLOCK)pArg;

  if (pBlock)
  {
    if (pBlock->hReadKey)
      CryptDestroyKey(pBlock->hReadKey);
    if (pBlock->hWriteKey)
      CryptDestroyKey(pBlock->hWriteKey);

    if (pBlock->pvCrypt)
      free(pBlock->pvCrypt);
  }
  free(pBlock);
}

// Once a password has been supplied and a key created, we don't keep the 
// original password for security purposes.  Therefore return NULL.
void sqlite3CodecGetKey(sqlite3 *db, int nDb, void **ppKey, int *pnKeyLen)
{
  *ppKey = NULL;
  *pnKeyLen = 0;