mirror of
				https://github.com/clearml/dropbear
				synced 2025-06-26 18:17:32 +00:00 
			
		
		
		
	
		
			
				
	
	
		
			79 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
This is Dropbear, a smallish SSH server and client.
 | 
						|
https://matt.ucc.asn.au/dropbear/dropbear.html
 | 
						|
 | 
						|
INSTALL has compilation instructions.
 | 
						|
 | 
						|
MULTI has instructions on making a multi-purpose binary (ie a single binary
 | 
						|
which performs multiple tasks, to save disk space)
 | 
						|
 | 
						|
SMALL has some tips on creating small binaries.
 | 
						|
 | 
						|
Please contact me if you have any questions/bugs found/features/ideas/comments etc :)
 | 
						|
There is also a mailing list http://lists.ucc.gu.uwa.edu.au/mailman/listinfo/dropbear
 | 
						|
 | 
						|
Matt Johnston
 | 
						|
matt@ucc.asn.au
 | 
						|
 | 
						|
 | 
						|
In the absence of detailed documentation, some notes follow:
 | 
						|
============================================================================
 | 
						|
 | 
						|
Server public key auth:
 | 
						|
 | 
						|
You can use ~/.ssh/authorized_keys in the same way as with OpenSSH, just put
 | 
						|
the key entries in that file. They should be of the form:
 | 
						|
 | 
						|
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEAwVa6M6cGVmUcLl2cFzkxEoJd06Ub4bVDsYrWvXhvUV+ZAM9uGuewZBDoAqNKJxoIn0Hyd0Nk/yU99UVv6NWV/5YSHtnf35LKds56j7cuzoQpFIdjNwdxAN0PCET/MG8qyskG/2IE2DPNIaJ3Wy+Ws4IZEgdJgPlTYUBWWtCWOGc= someone@hostname
 | 
						|
 | 
						|
You must make sure that ~/.ssh, and the key file, are only writable by the
 | 
						|
user. Beware of editors that split the key into multiple lines.
 | 
						|
 | 
						|
Dropbear supports some options for authorized_keys entries, see the manpage.
 | 
						|
 | 
						|
============================================================================
 | 
						|
 | 
						|
Client public key auth:
 | 
						|
 | 
						|
Dropbear can do public key auth as a client, but you will have to convert
 | 
						|
OpenSSH style keys to Dropbear format, or use dropbearkey to create them.
 | 
						|
 | 
						|
If you have an OpenSSH-style private key ~/.ssh/id_rsa, you need to do:
 | 
						|
 | 
						|
dropbearconvert openssh dropbear ~/.ssh/id_rsa  ~/.ssh/id_rsa.db
 | 
						|
dbclient -i ~/.ssh/id_rsa.db <hostname>
 | 
						|
 | 
						|
Dropbear does not support encrypted hostkeys though can connect to ssh-agent.
 | 
						|
 | 
						|
============================================================================
 | 
						|
 | 
						|
If you want to get the public-key portion of a Dropbear private key, look at
 | 
						|
dropbearkey's '-y' option.
 | 
						|
 | 
						|
============================================================================
 | 
						|
 | 
						|
To run the server, you need to generate server keys, this is one-off:
 | 
						|
./dropbearkey -t rsa -f dropbear_rsa_host_key
 | 
						|
./dropbearkey -t dss -f dropbear_dss_host_key
 | 
						|
./dropbearkey -t ecdsa -f dropbear_ecdsa_host_key
 | 
						|
 | 
						|
or alternatively convert OpenSSH keys to Dropbear:
 | 
						|
./dropbearconvert openssh dropbear /etc/ssh/ssh_host_dsa_key dropbear_dss_host_key
 | 
						|
 | 
						|
You can also get Dropbear to create keys when the first connection is made -
 | 
						|
this is preferable to generating keys when the system boots. Make sure 
 | 
						|
/etc/dropbear/ exists and then pass '-R' to the dropbear server.
 | 
						|
 | 
						|
============================================================================
 | 
						|
 | 
						|
If the server is run as non-root, you most likely won't be able to allocate a
 | 
						|
pty, and you cannot login as any user other than that running the daemon
 | 
						|
(obviously). Shadow passwords will also be unusable as non-root.
 | 
						|
 | 
						|
============================================================================
 | 
						|
 | 
						|
The Dropbear distribution includes a standalone version of OpenSSH's scp
 | 
						|
program. You can compile it with "make scp", you may want to change the path
 | 
						|
of the ssh binary, specified by _PATH_SSH_PROGRAM in options.h . By default
 | 
						|
the progress meter isn't compiled in to save space, you can enable it by 
 | 
						|
adding 'SCPPROGRESS=1' to the make commandline.
 |