svcadm(1M) 을 검색하려면 섹션에서 1M 을 선택하고, 맨페이지명에 svcadm을 입력하고 검색을 누른다.
ssh-keyscan
Name
ssh-keyscan - gather public ssh host keys of a number of
hosts
Synopsis
ssh-keyscan [-v46] [-p port] [-T timeout] [-t type]
[-f file] [-] [host... | addrlist namelist] [...]
Description
ssh-keyscan is a utility for gathering the public ssh host
keys of a number of hosts. It was designed to aid in build-
ing and verifying ssh_known_hosts files. ssh-keyscan pro-
vides a minimal interface suitable for use by shell and perl
scripts. The output of ssh-keyscan is directed to standard
output.
ssh-keyscan uses non-blocking socket I/O to contact as many
hosts as possible in parallel, so it is very efficient. The
keys from a domain of 1,000 hosts can be collected in tens
of seconds, even when some of those hosts are down or do not
run ssh. For scanning, one does not need login access to the
machines that are being scanned, nor does the scanning pro-
cess involve any encryption.
File Format
Input format:
1.2.3.4,1.2.4.4
name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4
Output format for rsa1 keys:
host-or-namelist bits exponent modulus
Output format for rsa and dsa keys, where keytype is either
ssh-rsa or `ssh-dsa:
host-or-namelist keytype base64-encoded-key
Options
The following options are supported:
-f filename
Read hosts or addrlist namelist pairs from this file,
one per line. If you specify - instead of a filename,
ssh-keyscan reads hosts or addrlist namelist pairs from
the standard input.
-p port
Port to connect to on the remote host.
-T timeout
Set the timeout for connection attempts. If timeout
seconds have elapsed since a connection was initiated to
a host or since the last time anything was read from
that host, the connection is closed and the host in
question is considered unavailable. The default is for
timeout is 5 seconds.
-t type
Specify the type of the key to fetch from the scanned
hosts. The possible values for type are rsa1 for proto-
col version 1 and rsa or dsa for protocol version 2.
Specify multiple values by separating them with commas.
The default is rsa1.
-v
Specify verbose mode. Print debugging messages about
progress.
-4
Force to use IPv4 addresses only.
-6
Forces to use IPv6 addresses only.
Security
If a ssh_known_hosts file is constructed using ssh-keyscan
without verifying the keys, users are vulnerable to man-in-
the-middle attacks. If the security model allows such a
risk, ssh-keyscan can help in the detection of tampered key-
files or man-in-the-middle attacks which have begun after
the ssh_known_hosts file was created.
Examples
Example 1 Printing the rsa1 Host Key
The following example prints the rsa1 host key for machine
hostname:
$ ssh-keyscan hostname
Example 2 Finding All Hosts
The following commands finds all hosts from the file
ssh_hosts which have new or different keys from those in the
sorted file ssh_known_hosts:
$ ssh-keyscan -t rsa,dsa -f ssh_hosts | \
sort -u - ssh_known_hosts | diff ssh_known_hosts -
Files
/etc/ssh_known_hosts
Contains list of public ssh host keys.
Exit Status
The following exit values are returned:
0
No usage errors. ssh-keyscan might or might not have
succeeded or failed to scan one, more or all of the
given hosts.
1
Usage error.
Attributes
See attributes(5) for descriptions of the following attri-
butes:
tab() box; cw(2.75i) |cw(2.75i) lw(2.75i) |lw(2.75i) ATTRI-
BUTE TYPEATTRIBUTE VALUE _ Availabilitynetwork/ssh _
Interface StabilityCommitted
See Also
ssh(1), sshd(1M), attributes(5)
Authors
David Mazieres wrote the initial version, and Wayne Davison
added support for protocol version 2.
Bugs
ssh-keyscan generates the following messages on the consoles
of all machines it scans if the server is older than version
2.9:
Connection closed by remote host
This is because ssh-keyscan opens a connection to the ssh
port, reads the public key, and drops the connection as soon
as it gets the key.