Function crypt_write_block

src/burp/mvol.cpp:313–355

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//
//
static void crypt_write_block(BurpGlobals* tdgbl, const UCHAR* buffer, FB_SIZE_T buffer_length, bool flash)
{
	if (!(tdgbl->gbl_sw_keyholder))
	{
		mvol_write_block(tdgbl, buffer, buffer_length);
		return;
	}

	start_crypt(tdgbl);
	fb_assert(tdgbl->gbl_crypt);

	while (buffer_length)
	{
		ULONG step = MIN(buffer_length + tdgbl->gbl_crypt_left, ZC_BUFSIZE);
		fb_assert(CRYPT_STEP < ZC_BUFSIZE);

		ULONG move = step - tdgbl->gbl_crypt_left;
		memcpy(tdgbl->gbl_crypt_buffer + tdgbl->gbl_crypt_left, buffer, move);
		buffer_length -= move;
		buffer += move;

		tdgbl->gbl_crypt_left = step % CRYPT_STEP;
		step -= tdgbl->gbl_crypt_left;

		if (flash && buffer_length == 0 && tdgbl->gbl_crypt_left)
		{
			step += CRYPT_STEP;
			tdgbl->gbl_crypt_left = 0;
		}

		FbLocalStatus status;

		for (ULONG offset = 0; offset < step; offset += CRYPT_STEP)
		{
			UCHAR* b = &tdgbl->gbl_crypt_buffer[offset];
			tdgbl->gbl_crypt->crypt_plugin->encrypt(&status, CRYPT_STEP, b, b);
			check(&status);
		}

		mvol_write_block(tdgbl, tdgbl->gbl_crypt_buffer, step);
		memmove(tdgbl->gbl_crypt_buffer, &tdgbl->gbl_crypt_buffer[step], tdgbl->gbl_crypt_left);
	}
}


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