Mercurial > dropbear
view dropbearkey.1 @ 1715:3974f087d9c0
Disallow leading lines before the ident for server (#102)
Per RFC4253 4.2 clients must be able to process other lines of data
before the version string, server behavior is not defined neither
with MUST/SHOULD nor with MAY.
If server process up to 50 lines too - it may cause too long hanging
session with invalid/evil client that consume host resources and
potentially may lead to DDoS on poor embedded boxes.
Let's require first line from client to be version string and fail
early if it's not - matches both RFC and real OpenSSH behavior.
author | Vladislav Grishenko <themiron@users.noreply.github.com> |
---|---|
date | Mon, 15 Jun 2020 18:22:18 +0500 |
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