openssh bugs - Jun 2008 - [Bug 1477] New: ssh-keygen not reading stdin as expected

https://bugzilla.mindrot.org/show_bug.cgi?id=1477

           Summary: ssh-keygen not reading stdin as expected
    Classification: Unclassified
           Product: Portable OpenSSH
           Version: 4.7p1
          Platform: ix86
        OS/Version: OpenBSD
            Status: NEW
          Severity: normal
          Priority: P2
         Component: ssh-keygen
        AssignedTo: unassigned-bugs at mindrot.org
        ReportedBy: lars at umich.edu


I see what looks like difficulty reading stdin using ssh-keyscan:

     $ ssh-keyscan -t rsa login.itd.umich.edu | ssh-keygen -l -f -
     -: No such file or directory

Instead of the error message "-: No such file or directory", I would
expect the output from ssh-keyscan to be read into ssh-keygen in the
above example and the fingerprint produced as output.

Doing it in two steps works:

 $ ssh-keyscan -t rsa login.itd.umich.edu >/tmp/x; \
   ssh-keygen -l -f /tmp/x
 # login.itd.umich.edu SSH-1.99-OpenSSH_4.6p1-hpn12v17
 1024 10:4a:ec:d2:f1:38:f7:ea:0a:a0:0f:17:57:ea:a6:16
login.itd.umich.edu

Option -f filename, Filename of the key file, seems to be the right
option and '-' is the usual way of indicating stdin.

FWIW trying to used /dev/stdin directly also gives an error

$ ssh-keyscan login.itd.umich.edu | ssh-keygen -l -f /dev/stdin
# login.itd.umich.edu SSH-1.99-OpenSSH_4.6p1-hpn12v17
/dev/stdin is not a public key file.

ssh-keygen seems not to have a way to show version.  This is at least
the following platforms:

   OpenBSD 4.2 GENERIC#3 i386
   OpenBSD 4.3 GENERIC#698 i386
   Linux 2.6.24-18-generic #1 SMP x86_64

The corresponding accompanying ssh show these versions:

   OpenSSH_4.7p1 Debian-8ubuntu1.2, OpenSSL 0.9.8g 19 Oct 2007
   OpenSSH_4.7, OpenSSL 0.9.7j 04 May 2006
   OpenSSH_4.8, OpenSSL 0.9.7j 04 May 2006

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https://bugzilla.mindrot.org/show_bug.cgi?id=1477


Darren Tucker <dtucker at zip.com.au> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |dtucker at zip.com.au




--- Comment #1 from Darren Tucker <dtucker at zip.com.au>  2008-06-16
04:16:58 ---
Try:

ssh-keyscan -t rsa login.itd.umich.edu | ssh-keygen -l -f /dev/stdin

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--- Comment #2 from Lars Nood?n <lars at umich.edu>  2008-06-16 04:59:16
---
The same behavior can be found on this platform and version:

 OpenBSD 4.3 GENERIC.MP#0 amd64
 OpenSSH_5.0, OpenSSL 0.9.7j 04 May 2006

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Damien Miller <djm at mindrot.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|4.7p1                       |-current
           Platform|ix86                        |All
         OS/Version|OpenBSD                     |All
           Severity|normal                      |enhancement
                 CC|                            |djm at mindrot.org




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--- Comment #3 from Lars Nood?n <lars at umich.edu>  2008-07-26 15:00:45
---
(Hmm.  I can see that replies via e-mail seem not to get piped back
into bugzilla here.)

Darren suggested a second way to produce the error:
    ssh-keyscan -t rsa login.itd.umich.edu | ssh-keygen -l -f
/dev/stdin

which gives the following error
/dev/stdin is not a public key file.

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--- Comment #4 from Lars Nood?n <lars at umich.edu>  2008-07-26 15:01:46
---
(Hmm.  I can see that replies via e-mail seem not to get piped back
into bugzilla here.)

Darren suggested a second way to produce the error:
    ssh-keyscan -t rsa login.itd.umich.edu | ssh-keygen -l -f
/dev/stdin

which gives the following error
    /dev/stdin is not a public key file.

It seems to be present in OpenSSH 5.1

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Jameson Rollins <ssh-bugzilla at finestructure.net> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ssh-bugzilla at finestructure.
                   |                            |net




--- Comment #5 from Jameson Rollins <ssh-bugzilla at finestructure.net> 
2008-11-18 04:55:46 ---
Hello.  I too would really like to see ssh-keygen be able to properly
read from stdin.  It would make many of the tasks I have to do much
much easier.  The current situation where input needs to be written to
an intermediate file is quite cumbersome.

It actually appears that reading of /dev/stdin may be broken, as
opposed to completely unsupported.  It appears that ssh-keygen will
read from a redirection of file, but not from a pipeline: 

servo:/tmp/cdtemp.laHoFb 0$ ssh-keygen -l -f id_rsa.pub 
1024 23:ff:58:10:19:b6:5d:4f:c9:92:28:00:57:2c:5a:c8 id_rsa.pub (RSA)
servo:/tmp/cdtemp.laHoFb 0$ ssh-keygen -l -f /dev/stdin <id_rsa.pub 
1024 23:ff:58:10:19:b6:5d:4f:c9:92:28:00:57:2c:5a:c8 /dev/stdin (RSA)
servo:/tmp/cdtemp.laHoFb 0$ cat id_rsa.pub | ssh-keygen -l -f
/dev/stdin
/dev/stdin is not a public key file.
servo:/tmp/cdtemp.laHoFb 1$ 

I don't understand why it would be behaving this way.

Thanks so much for such a great program.

servo:/tmp/cdtemp.laHoFb 0$ ssh -V
OpenSSH_5.1p1 Debian-3, OpenSSL 0.9.8g 19 Oct 2007
servo:/tmp/cdtemp.laHoFb 0$

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Alexandre Dulaunoy <a at foo.be> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |a at foo.be




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