Cross Reference: /freebsd-10.2-release/crypto/openssh/ssh-keyscan.0

ssh-keyscan.0 (207311)	ssh-keyscan.0 (214979)
1SSH-KEYSCAN(1) OpenBSD Reference Manual SSH-KEYSCAN(1) 2 3NAME 4 ssh-keyscan - gather ssh public keys 5 6SYNOPSIS 7 ssh-keyscan [-46Hv] [-f file] [-p port] [-T timeout] [-t type] 8 [host \| addrlist namelist] ... 9 10DESCRIPTION	1SSH-KEYSCAN(1) OpenBSD Reference Manual SSH-KEYSCAN(1) 2 3NAME 4 ssh-keyscan - gather ssh public keys 5 6SYNOPSIS 7 ssh-keyscan [-46Hv] [-f file] [-p port] [-T timeout] [-t type] 8 [host \| addrlist namelist] ... 9 10DESCRIPTION
11 ssh-keyscan is a utility for gathering the public ssh host keys of a num- 12 ber of hosts. It was designed to aid in building and verifying	11 ssh-keyscan is a utility for gathering the public ssh host keys of a 12 number of hosts. It was designed to aid in building and verifying
13 ssh_known_hosts files. ssh-keyscan provides a minimal interface suitable 14 for use by shell and perl scripts. 15	13 ssh_known_hosts files. ssh-keyscan provides a minimal interface suitable 14 for use by shell and perl scripts. 15
16 ssh-keyscan uses non-blocking socket I/O to contact as many hosts as pos- 17 sible in parallel, so it is very efficient. The keys from a domain of	16 ssh-keyscan uses non-blocking socket I/O to contact as many hosts as 17 possible in parallel, so it is very efficient. The keys from a domain of
18 1,000 hosts can be collected in tens of seconds, even when some of those 19 hosts are down or do not run ssh. For scanning, one does not need login	18 1,000 hosts can be collected in tens of seconds, even when some of those 19 hosts are down or do not run ssh. For scanning, one does not need login
20 access to the machines that are being scanned, nor does the scanning pro- 21 cess involve any encryption.	20 access to the machines that are being scanned, nor does the scanning 21 process involve any encryption.
22 23 The options are as follows: 24 25 -4 Forces ssh-keyscan to use IPv4 addresses only. 26 27 -6 Forces ssh-keyscan to use IPv6 addresses only. 28 29 -f file 30 Read hosts or addrlist namelist pairs from this file, one per 31 line. If - is supplied instead of a filename, ssh-keyscan will 32 read hosts or addrlist namelist pairs from the standard input. 33 34 -H Hash all hostnames and addresses in the output. Hashed names may	22 23 The options are as follows: 24 25 -4 Forces ssh-keyscan to use IPv4 addresses only. 26 27 -6 Forces ssh-keyscan to use IPv6 addresses only. 28 29 -f file 30 Read hosts or addrlist namelist pairs from this file, one per 31 line. If - is supplied instead of a filename, ssh-keyscan will 32 read hosts or addrlist namelist pairs from the standard input. 33 34 -H Hash all hostnames and addresses in the output. Hashed names may
35 be used normally by ssh and sshd, but they do not reveal identi- 36 fying information should the file's contents be disclosed.	35 be used normally by ssh and sshd, but they do not reveal 36 identifying information should the file's contents be disclosed.
37 38 -p port 39 Port to connect to on the remote host. 40 41 -T timeout 42 Set the timeout for connection attempts. If timeout seconds have 43 elapsed since a connection was initiated to a host or since the 44 last time anything was read from that host, then the connection	37 38 -p port 39 Port to connect to on the remote host. 40 41 -T timeout 42 Set the timeout for connection attempts. If timeout seconds have 43 elapsed since a connection was initiated to a host or since the 44 last time anything was read from that host, then the connection
45 is closed and the host in question considered unavailable. De- 46 fault is 5 seconds.	45 is closed and the host in question considered unavailable. 46 Default is 5 seconds.
47 48 -t type 49 Specifies the type of the key to fetch from the scanned hosts. 50 The possible values are ``rsa1'' for protocol version 1 and 51 ``rsa'' or ``dsa'' for protocol version 2. Multiple values may 52 be specified by separating them with commas. The default is 53 ``rsa''. 54 55 -v Verbose mode. Causes ssh-keyscan to print debugging messages 56 about its progress. 57 58SECURITY	47 48 -t type 49 Specifies the type of the key to fetch from the scanned hosts. 50 The possible values are ``rsa1'' for protocol version 1 and 51 ``rsa'' or ``dsa'' for protocol version 2. Multiple values may 52 be specified by separating them with commas. The default is 53 ``rsa''. 54 55 -v Verbose mode. Causes ssh-keyscan to print debugging messages 56 about its progress. 57 58SECURITY
59 If an ssh_known_hosts file is constructed using ssh-keyscan without veri- 60 fying the keys, users will be vulnerable to man in the middle attacks. 61 On the other hand, if the security model allows such a risk, ssh-keyscan 62 can help in the detection of tampered keyfiles or man in the middle at- 63 tacks which have begun after the ssh_known_hosts file was created.	59 If an ssh_known_hosts file is constructed using ssh-keyscan without 60 verifying the keys, users will be vulnerable to man in the middle 61 attacks. On the other hand, if the security model allows such a risk, 62 ssh-keyscan can help in the detection of tampered keyfiles or man in the 63 middle attacks which have begun after the ssh_known_hosts file was 64 created.
64 65FILES 66 Input format: 67 68 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4 69 70 Output format for rsa1 keys: 71 --- 27 unchanged lines hidden (view full) --- 99 2. 100 101BUGS 102 It generates "Connection closed by remote host" messages on the consoles 103 of all the machines it scans if the server is older than version 2.9. 104 This is because it opens a connection to the ssh port, reads the public 105 key, and drops the connection as soon as it gets the key. 106	65 66FILES 67 Input format: 68 69 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4 70 71 Output format for rsa1 keys: 72 --- 27 unchanged lines hidden (view full) --- 100 2. 101 102BUGS 103 It generates "Connection closed by remote host" messages on the consoles 104 of all the machines it scans if the server is older than version 2.9. 105 This is because it opens a connection to the ssh port, reads the public 106 key, and drops the connection as soon as it gets the key. 107
107OpenBSD 4.7 January 9, 2010 2	108OpenBSD 4.8 January 9, 2010 OpenBSD 4.8

1SSH-KEYSCAN(1) OpenBSD Reference Manual SSH-KEYSCAN(1)
2
3NAME
4 ssh-keyscan - gather ssh public keys
5
6SYNOPSIS
7 ssh-keyscan [-46Hv] [-f file] [-p port] [-T timeout] [-t type]
8 [host | addrlist namelist] ...
9
10DESCRIPTION

11 ssh-keyscan is a utility for gathering the public ssh host keys of a num-
12 ber of hosts. It was designed to aid in building and verifying

11 ssh-keyscan is a utility for gathering the public ssh host keys of a
12 number of hosts. It was designed to aid in building and verifying

13 ssh_known_hosts files. ssh-keyscan provides a minimal interface suitable
14 for use by shell and perl scripts.
15

16 ssh-keyscan uses non-blocking socket I/O to contact as many hosts as pos-
17 sible in parallel, so it is very efficient. The keys from a domain of

16 ssh-keyscan uses non-blocking socket I/O to contact as many hosts as
17 possible in parallel, so it is very efficient. The keys from a domain of

18 1,000 hosts can be collected in tens of seconds, even when some of those
19 hosts are down or do not run ssh. For scanning, one does not need login

20 access to the machines that are being scanned, nor does the scanning pro-
21 cess involve any encryption.

20 access to the machines that are being scanned, nor does the scanning
21 process involve any encryption.

22
23 The options are as follows:
24
25 -4 Forces ssh-keyscan to use IPv4 addresses only.
26
27 -6 Forces ssh-keyscan to use IPv6 addresses only.
28
29 -f file
30 Read hosts or addrlist namelist pairs from this file, one per
31 line. If - is supplied instead of a filename, ssh-keyscan will
32 read hosts or addrlist namelist pairs from the standard input.
33
34 -H Hash all hostnames and addresses in the output. Hashed names may

35 be used normally by ssh and sshd, but they do not reveal identi-
36 fying information should the file's contents be disclosed.

35 be used normally by ssh and sshd, but they do not reveal
36 identifying information should the file's contents be disclosed.

37
38 -p port
39 Port to connect to on the remote host.
40
41 -T timeout
42 Set the timeout for connection attempts. If timeout seconds have
43 elapsed since a connection was initiated to a host or since the
44 last time anything was read from that host, then the connection

45 is closed and the host in question considered unavailable. De-
46 fault is 5 seconds.

45 is closed and the host in question considered unavailable.
46 Default is 5 seconds.

47
48 -t type
49 Specifies the type of the key to fetch from the scanned hosts.
50 The possible values are ``rsa1'' for protocol version 1 and
51 ``rsa'' or ``dsa'' for protocol version 2. Multiple values may
52 be specified by separating them with commas. The default is
53 ``rsa''.
54
55 -v Verbose mode. Causes ssh-keyscan to print debugging messages
56 about its progress.
57
58SECURITY

59 If an ssh_known_hosts file is constructed using ssh-keyscan without veri-
60 fying the keys, users will be vulnerable to man in the middle attacks.
61 On the other hand, if the security model allows such a risk, ssh-keyscan
62 can help in the detection of tampered keyfiles or man in the middle at-
63 tacks which have begun after the ssh_known_hosts file was created.

59 If an ssh_known_hosts file is constructed using ssh-keyscan without
60 verifying the keys, users will be vulnerable to man in the middle
61 attacks. On the other hand, if the security model allows such a risk,
62 ssh-keyscan can help in the detection of tampered keyfiles or man in the
63 middle attacks which have begun after the ssh_known_hosts file was
64 created.

64
65FILES
66 Input format:
67
68 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4
69
70 Output format for rsa1 keys:
71

--- 27 unchanged lines hidden (view full) ---

99 2.
100
101BUGS
102 It generates "Connection closed by remote host" messages on the consoles
103 of all the machines it scans if the server is older than version 2.9.
104 This is because it opens a connection to the ssh port, reads the public
105 key, and drops the connection as soon as it gets the key.
106

65
66FILES
67 Input format:
68
69 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4
70
71 Output format for rsa1 keys:
72

--- 27 unchanged lines hidden (view full) ---

100 2.
101
102BUGS
103 It generates "Connection closed by remote host" messages on the consoles
104 of all the machines it scans if the server is older than version 2.9.
105 This is because it opens a connection to the ssh port, reads the public
106 key, and drops the connection as soon as it gets the key.
107

107OpenBSD 4.7 January 9, 2010 2

108OpenBSD 4.8 January 9, 2010 OpenBSD 4.8