DKIM-Filter:	OpenDKIM Filter v2.11.0 delorie.com 49OHqIoY4185760
Authentication-Results:	delorie.com;
	dkim=pass (1024-bit key, unprotected) header.d=cygwin.com header.i=@cygwin.com header.a=rsa-sha256 header.s=default header.b=LoBEExBZ
X-Recipient:	archive-cygwin AT delorie DOT com
DKIM-Filter:	OpenDKIM Filter v2.11.0 sourceware.org 9C325385841F
DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=cygwin.com;
	s=default; t=1729792337;
	bh=vVXJfUS/zw6YF4CMkonwsLulbRPc7/vyifoLY7k5g4I=;
	h=Subject:To:References:Date:In-Reply-To:List-Id:List-Unsubscribe:
	List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc:
	From;
	b=LoBEExBZ7IePy6vEXrtuMMJLD5WYWC6SExj1QX4RM/ajQdyNh+ND9NHmzWNapT4ZE
	diCOBI0FZQDZdzBGAX1LgF/FF7z6cYOXEM11iw7Vb/CliEyoqneiJlbwgmwI97z4UC
	0pKs3YPaxBHMLUEgrn7hCUNfw53xO2+G+woxZe7w=
X-Original-To:	cygwin AT cygwin DOT com
Delivered-To:	cygwin AT cygwin DOT com
DMARC-Filter:	OpenDMARC Filter v1.4.2 sourceware.org 7C4043858D21
ARC-Filter:	OpenARC Filter v1.0.0 sourceware.org 7C4043858D21
ARC-Seal:	i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1729792267; cv=none;
	b=jlNaB9l557+rhtZR1fGV3/Flr6sc0dpHTgfMqdxJw09lQRPc21f3LEHThs5AcM7jHjq9o71TGlj3DCE42FoMclmhqu8hLikdLKzq6oMB6keoANChmbDKNUSBadks9PF/e4bROgCPHXWplh5EVN3uFBgOPHcsskCD2BnQ7a0eiJU=
ARC-Message-Signature:	i=1; a=rsa-sha256; d=sourceware.org; s=key;
	t=1729792267; c=relaxed/simple;
	bh=lNqrGef1AyIpE88FTbZ9/OtL13QCH2ZY7la02EGh/DU=;
	h=Subject:To:From:Message-ID:Date:MIME-Version;
	b=M/aHx2OpdKk/Nb1at3BRNsvvAYYnQk/wQjqsLuSlwjByBhEH06ra9VZ9bznVjLN0UlsdcwY5T+ZLd3FGcOir7+x+TzWFQSRarFMwlxwgvjAF6dhv/dmqoxqyhaW97QZiSDrQPPCLCUtTuKhdfCqOU8K/zFO5zCikrmiK8vWmWmc=
ARC-Authentication-Results:	i=1; server2.sourceware.org
Subject:	Re: Writing to '\\.\X:' that has no backing PhysicalDrive?
To:	cygwin AT cygwin DOT com
References:	<a6a5b28d-9d57-4b5d-82b2-b4090e55e1fd AT gmail DOT com>
Message-ID:	<85bb9413-91f0-5776-3f0a-3917e5a153ad@t-online.de>
Date:	Thu, 24 Oct 2024 19:50:47 +0200
User-Agent:	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
	SeaMonkey/2.53.18.2
MIME-Version:	1.0
In-Reply-To:	<a6a5b28d-9d57-4b5d-82b2-b4090e55e1fd@gmail.com>
X-TOI-EXPURGATEID:	150726::1729792248-60FF75EF-E2D83E63/0/0 CLEAN NORMAL
X-TOI-MSGID:	8ad41fc9-270b-4c86-a147-6a609342febd
X-Spam-Status:	No, score=-5.5 required=5.0 tests=BAYES_00, FREEMAIL_FROM,
	KAM_DMARC_STATUS, NICE_REPLY_A, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,
	SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version:	SpamAssassin 3.4.6 (2021-04-09) on
	server2.sourceware.org
X-BeenThere:	cygwin AT cygwin DOT com
X-Mailman-Version:	2.1.30
List-Id:	General Cygwin discussions and problem reports <cygwin.cygwin.com>
List-Unsubscribe:	<https://cygwin.com/mailman/options/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=unsubscribe>
List-Archive:	<https://cygwin.com/pipermail/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-request AT cygwin DOT com?subject=help>
List-Subscribe:	<https://cygwin.com/mailman/listinfo/cygwin>,
	<mailto:cygwin-request AT cygwin DOT com?subject=subscribe>
From:	Christian Franke via Cygwin <cygwin AT cygwin DOT com>
Reply-To:	cygwin AT cygwin DOT com
Cc:	Christian Franke <Christian DOT Franke AT t-online DOT de>
Errors-To:	cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com
Sender:	"Cygwin" <cygwin-bounces~archive-cygwin=delorie DOT com AT cygwin DOT com>

Ilya Basin via Cygwin wrote:
> Hi.
> I was trying to write an .img file to a VeraCrypt drive.
> VeraCrypt doesn't create a virtual PhysicalDrive so tools like Rufus don't see it.
> I hoped that with cygwin I would be able to do that, but Cygwin only creates /dev/sd?? nodes for PhysicalDrive partitions.
> I tried `dd` with '\\.\X:', but it can't open for writing because it treats it as a directory (reading succeeds).
>
> $ dd count=1 if='\\.\E:' | xxd
> 1+0 records in
> 1+0 records out
> 512 bytes copied, 0.0213007 s, 24.0 kB/s
> 00000000: eb52 904e 5446 5320 2020 2000 0208 0000  .R.NTFS    .....
> ...
>
> $ dd if=/dev/null count=0 of='\\.\E:'
> dd: failed to open '\\.\E:': Is a directory

Could reproduce this. The inconsistency between open for reading vs. 
writing of '\\.\E:' is actually interesting. Subtle bug in Cygwin?


>
> Same error in MSYS2.
>
> Does cygwin provide some (hidden) /dev/ nodes for drive letters or volumes like "\\?\Volume{GUID}"? Can I create one with mknod?

Alternatively, VeraCrypt Volumes could be accessed via:

$ ls -l /proc/sys/DosDevices/E:
lr--r--r-- 1 ... /proc/sys/DosDevices/E: -> 
/proc/sys/Device/VeraCryptVolumeE

But /proc/sys is completely R/O like /proc/registry, so you cannot write 
the image via this path.

OT:
/proc/sys/Device/HarddiskVolumeShadowCopyN[/PATH/TO/FILE] allows to read 
the image and individual files from a volume shadow copy.

-- 
Regards,
Christian


-- 
Problem reports:      https://cygwin.com/problems.html
FAQ:                  https://cygwin.com/faq/
Documentation:        https://cygwin.com/docs.html
Unsubscribe info:     https://cygwin.com/ml/#unsubscribe-simple

- Raw text -