[Pkg-shadow-devel] Bug#1124835: Bug#1124835: Bug#1124835: chpasswd hash check goes too far

[Chris Hofstaedtler]

* Chris Hofstaedtler <zeha at debian.org> [260108 00:19]:
>On Wed, Jan 07, 2026 at 07:50:57AM -0600, Serge E. Hallyn wrote:
>> On Wed, Jan 07, 2026 at 11:18:49AM +0100, Chris Hofstaedtler wrote:
>> > Hi,
>> >
>> > thanks. I've opened a report upstream.
>> > https://github.com/shadow-maint/shadow/issues/1483
>> >
>> > On Wed, Jan 07, 2026 at 09:24:35AM +0100, Marc Haber wrote:
>> > > On Wed, Jan 07, 2026 at 08:58:15AM +0100, Marc Haber wrote:
>> > > > This is even worse now, chpasswd won't accept a perfectly valid yescrypt
>> > > > hash:
>> > > >
>> > > > $ echo 9hKGOX79oaP4FEhQ2xQ6wLvPXsTTUtPiYu4QCXsc | mkpasswd --hash=yescrypt --stdin
>> > > > $y$j9T$VPuG6eC6CTZG7fxHR1YwP0$kZeswr5rIJKCXbeLvE/R412AO4vB1HLwuBrqg1nnPU4
>> > > > # echo "aust:$y$j9T$VPuG6eC6CTZG7fxHR1YwP0$kZeswr5rIJKCXbeLvE/R412AO4vB1HLwuBrqg1nnPU4" | chpasswd --encrypted
>> > > > chpasswd: (line 1, user aust) invalid password hash
>> > > > chpasswd: error detected, changes ignored
>
>As noted by vinz, this is user error. After bash variable
>interpolation, this became echo 'aust:' | chpasswd --encrypted. Not
>what you wanted, I guess.

Sorry, my bad. It became:

echo 'aust:/R412AO4vB1HLwuBrqg1nnPU4' | chpasswd --encrypted

Chris