Mercurial > dropbear
view dropbearkey.1 @ 1930:299f4f19ba19
Add /usr/sbin and /sbin to default root PATH
When dropbear is used in a very restricted environment (such as in a
initrd), the default user shell is often also very restricted
and doesn't take care of setting the PATH so the user ends up
with the PATH set by dropbear. Unfortunately, dropbear always
sets "/usr/bin:/bin" as default PATH even for the root user
which should have /usr/sbin and /sbin too.
For a concrete instance of this problem, see the "Remote Unlocking"
section in this tutorial: https://paxswill.com/blog/2013/11/04/encrypted-raspberry-pi/
It speaks of a bug in the initramfs script because it's written "blkid"
instead of "/sbin/blkid"... this is just because the scripts from the
initramfs do not expect to have a PATH without the sbin directories and
because dropbear is not setting the PATH appropriately for the root user.
I'm thus suggesting to use the attached patch to fix this misbehaviour (I
did not test it, but it's easy enough). It might seem anecdotic but
multiple Kali users have been bitten by this.
From https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=903403
| author | Raphael Hertzog <hertzog@debian.org> |
|---|---|
| date | Mon, 09 Jul 2018 16:27:53 +0200 |
| parents | 5c8913b7464c |
| children |
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.TH dropbearkey 1 .SH NAME dropbearkey \- create private keys for the use with dropbear(8) or dbclient(1) .SH SYNOPSIS .B dropbearkey \-t .I type \-f .I file [\-s .IR bits ] [\-y] .SH DESCRIPTION .B dropbearkey generates a \fIRSA\fR, \fIDSS\fR, \fIECDSA\fR, or \fIEd25519\fR format SSH private key, and saves it to a file for the use with the Dropbear client or server. Note that some SSH implementations use the term "DSA" rather than "DSS", they mean the same thing. .SH OPTIONS .TP .B \-t \fItype Type of key to generate. Must be one of .I rsa .I ecdsa .I ed25519 or .IR dss . .TP .B \-f \fIfile Write the secret key to the file \fIfile\fR. For client authentication ~/.ssh/id_dropbear is loaded by default .TP .B \-s \fIbits Set the key size to .I bits bits, should be multiple of 8 (optional). .TP .B \-y Just print the publickey and fingerprint for the private key in \fIfile\fR. .SH NOTES The program dropbearconvert(1) can be used to convert between Dropbear and OpenSSH key formats. .P Dropbear does not support encrypted keys. .SH EXAMPLE generate a host-key: # dropbearkey -t rsa -f /etc/dropbear/dropbear_rsa_host_key extract a public key suitable for authorized_keys from private key: # dropbearkey -y -f id_rsa | grep "^ssh-rsa " >> authorized_keys .SH AUTHOR Matt Johnston ([email protected]). .br Gerrit Pape ([email protected]) wrote this manual page. .SH SEE ALSO dropbear(8), dbclient(1), dropbearconvert(1) .P https://matt.ucc.asn.au/dropbear/dropbear.html