diff options
author | Colin Watson <cjwatson@debian.org> | 2018-04-03 08:20:28 +0100 |
---|---|---|
committer | Colin Watson <cjwatson@debian.org> | 2018-04-03 08:20:28 +0100 |
commit | ed6ae9c1a014a08ff5db3d768f01f2e427eeb476 (patch) | |
tree | 601025e307745d351946c01ab13f419ddb6dae29 /ssh-keyscan.0 | |
parent | 62f54f20bf351468e0124f63cc2902ee40d9b0e9 (diff) | |
parent | a0349a1cc4a18967ad1dbff5389bcdf9da098814 (diff) |
Import openssh_7.7p1.orig.tar.gz
Diffstat (limited to 'ssh-keyscan.0')
-rw-r--r-- | ssh-keyscan.0 | 80 |
1 files changed, 35 insertions, 45 deletions
diff --git a/ssh-keyscan.0 b/ssh-keyscan.0 index 1a9751ef1..c0278ee0a 100644 --- a/ssh-keyscan.0 +++ b/ssh-keyscan.0 | |||
@@ -1,62 +1,66 @@ | |||
1 | SSH-KEYSCAN(1) General Commands Manual SSH-KEYSCAN(1) | 1 | SSH-KEYSCAN(1) General Commands Manual SSH-KEYSCAN(1) |
2 | 2 | ||
3 | NAME | 3 | NAME |
4 | ssh-keyscan M-bM-^@M-^S gather ssh public keys | 4 | ssh-keyscan M-bM-^@M-^S gather SSH public keys |
5 | 5 | ||
6 | SYNOPSIS | 6 | SYNOPSIS |
7 | ssh-keyscan [-46cHv] [-f file] [-p port] [-T timeout] [-t type] | 7 | ssh-keyscan [-46cDHv] [-f file] [-p port] [-T timeout] [-t type] |
8 | [host | addrlist namelist] ... | 8 | [host | addrlist namelist] |
9 | 9 | ||
10 | DESCRIPTION | 10 | DESCRIPTION |
11 | ssh-keyscan is a utility for gathering the public ssh host keys of a | 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 | 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 | 13 | ssh_known_hosts files, the format of which is documented in sshd(8). |
14 | for use by shell and perl scripts. | 14 | ssh-keyscan provides a minimal interface suitable for use by shell and |
15 | perl scripts. | ||
15 | 16 | ||
16 | ssh-keyscan uses non-blocking socket I/O to contact as many hosts as | 17 | 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 | 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 | 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 | hosts are down or do not run sshd(8). For scanning, one does not need |
20 | access to the machines that are being scanned, nor does the scanning | 21 | login access to the machines that are being scanned, nor does the |
21 | process involve any encryption. | 22 | scanning process involve any encryption. |
22 | 23 | ||
23 | The options are as follows: | 24 | The options are as follows: |
24 | 25 | ||
25 | -4 Forces ssh-keyscan to use IPv4 addresses only. | 26 | -4 Force ssh-keyscan to use IPv4 addresses only. |
26 | 27 | ||
27 | -6 Forces ssh-keyscan to use IPv6 addresses only. | 28 | -6 Force ssh-keyscan to use IPv6 addresses only. |
28 | 29 | ||
29 | -c Request certificates from target hosts instead of plain keys. | 30 | -c Request certificates from target hosts instead of plain keys. |
30 | 31 | ||
32 | -D Print keys found as SSHFP DNS records. The default is to print | ||
33 | keys in a format usable as a ssh(1) known_hosts file. | ||
34 | |||
31 | -f file | 35 | -f file |
32 | Read hosts or M-bM-^@M-^\addrlist namelistM-bM-^@M-^] pairs from file, one per line. | 36 | Read hosts or M-bM-^@M-^\addrlist namelistM-bM-^@M-^] pairs from file, one per line. |
33 | If - is supplied instead of a filename, ssh-keyscan will read | 37 | If M-bM-^@M-^X-M-bM-^@M-^Y is supplied instead of a filename, ssh-keyscan will read |
34 | hosts or M-bM-^@M-^\addrlist namelistM-bM-^@M-^] pairs from the standard input. | 38 | from the standard input. Input is expected in the format: |
39 | |||
40 | 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4 | ||
35 | 41 | ||
36 | -H Hash all hostnames and addresses in the output. Hashed names may | 42 | -H Hash all hostnames and addresses in the output. Hashed names may |
37 | be used normally by ssh and sshd, but they do not reveal | 43 | be used normally by ssh(1) and sshd(8), but they do not reveal |
38 | identifying information should the file's contents be disclosed. | 44 | identifying information should the file's contents be disclosed. |
39 | 45 | ||
40 | -p port | 46 | -p port |
41 | Port to connect to on the remote host. | 47 | Connect to port on the remote host. |
42 | 48 | ||
43 | -T timeout | 49 | -T timeout |
44 | Set the timeout for connection attempts. If timeout seconds have | 50 | Set the timeout for connection attempts. If timeout seconds have |
45 | elapsed since a connection was initiated to a host or since the | 51 | elapsed since a connection was initiated to a host or since the |
46 | last time anything was read from that host, then the connection | 52 | last time anything was read from that host, the connection is |
47 | is closed and the host in question considered unavailable. | 53 | closed and the host in question considered unavailable. The |
48 | Default is 5 seconds. | 54 | default is 5 seconds. |
49 | 55 | ||
50 | -t type | 56 | -t type |
51 | Specifies the type of the key to fetch from the scanned hosts. | 57 | Specify the type of the key to fetch from the scanned hosts. The |
52 | The possible values are M-bM-^@M-^\dsaM-bM-^@M-^], M-bM-^@M-^\ecdsaM-bM-^@M-^], M-bM-^@M-^\ed25519M-bM-^@M-^], or M-bM-^@M-^\rsaM-bM-^@M-^]. | 58 | possible values are M-bM-^@M-^\dsaM-bM-^@M-^], M-bM-^@M-^\ecdsaM-bM-^@M-^], M-bM-^@M-^\ed25519M-bM-^@M-^], or M-bM-^@M-^\rsaM-bM-^@M-^]. |
53 | Multiple values may be specified by separating them with commas. | 59 | Multiple values may be specified by separating them with commas. |
54 | The default is to fetch M-bM-^@M-^\rsaM-bM-^@M-^], M-bM-^@M-^\ecdsaM-bM-^@M-^], and M-bM-^@M-^\ed25519M-bM-^@M-^] keys. | 60 | The default is to fetch M-bM-^@M-^\rsaM-bM-^@M-^], M-bM-^@M-^\ecdsaM-bM-^@M-^], and M-bM-^@M-^\ed25519M-bM-^@M-^] keys. |
55 | 61 | ||
56 | -v Verbose mode. Causes ssh-keyscan to print debugging messages | 62 | -v Verbose mode: print debugging messages about progress. |
57 | about its progress. | ||
58 | 63 | ||
59 | SECURITY | ||
60 | If an ssh_known_hosts file is constructed using ssh-keyscan without | 64 | If an ssh_known_hosts file is constructed using ssh-keyscan without |
61 | verifying the keys, users will be vulnerable to man in the middle | 65 | verifying the keys, users will be vulnerable to man in the middle |
62 | attacks. On the other hand, if the security model allows such a risk, | 66 | attacks. On the other hand, if the security model allows such a risk, |
@@ -65,42 +69,28 @@ SECURITY | |||
65 | created. | 69 | created. |
66 | 70 | ||
67 | FILES | 71 | FILES |
68 | Input format: | ||
69 | |||
70 | 1.2.3.4,1.2.4.4 name.my.domain,name,n.my.domain,n,1.2.3.4,1.2.4.4 | ||
71 | |||
72 | Output format for RSA, DSA, ECDSA, and Ed25519 keys: | ||
73 | |||
74 | host-or-namelist keytype base64-encoded-key | ||
75 | |||
76 | Where keytype is either M-bM-^@M-^\ecdsa-sha2-nistp256M-bM-^@M-^], M-bM-^@M-^\ecdsa-sha2-nistp384M-bM-^@M-^], | ||
77 | M-bM-^@M-^\ecdsa-sha2-nistp521M-bM-^@M-^], M-bM-^@M-^\ssh-ed25519M-bM-^@M-^], M-bM-^@M-^\ssh-dssM-bM-^@M-^] or M-bM-^@M-^\ssh-rsaM-bM-^@M-^]. | ||
78 | |||
79 | /etc/ssh/ssh_known_hosts | 72 | /etc/ssh/ssh_known_hosts |
80 | 73 | ||
81 | EXAMPLES | 74 | EXAMPLES |
82 | Print the rsa host key for machine hostname: | 75 | Print the RSA host key for machine hostname: |
83 | 76 | ||
84 | $ ssh-keyscan hostname | 77 | $ ssh-keyscan -t rsa hostname |
85 | 78 | ||
86 | Find all hosts from the file ssh_hosts which have new or different keys | 79 | Find all hosts from the file ssh_hosts which have new or different keys |
87 | from those in the sorted file ssh_known_hosts: | 80 | from those in the sorted file ssh_known_hosts: |
88 | 81 | ||
89 | $ ssh-keyscan -t rsa,dsa,ecdsa,ed25519 -f ssh_hosts | \ | 82 | $ ssh-keyscan -t rsa,dsa,ecdsa,ed25519 -f ssh_hosts | \ |
90 | sort -u - ssh_known_hosts | diff ssh_known_hosts - | 83 | sort -u - ssh_known_hosts | diff ssh_known_hosts - |
91 | 84 | ||
92 | SEE ALSO | 85 | SEE ALSO |
93 | ssh(1), sshd(8) | 86 | ssh(1), sshd(8) |
94 | 87 | ||
88 | Using DNS to Securely Publish Secure Shell (SSH) Key Fingerprints, RFC | ||
89 | 4255, 2006. | ||
90 | |||
95 | AUTHORS | 91 | AUTHORS |
96 | David Mazieres <dm@lcs.mit.edu> wrote the initial version, and Wayne | 92 | David Mazieres <dm@lcs.mit.edu> wrote the initial version, and Wayne |
97 | Davison <wayned@users.sourceforge.net> added support for protocol version | 93 | Davison <wayned@users.sourceforge.net> added support for protocol version |
98 | 2. | 94 | 2. |
99 | 95 | ||
100 | BUGS | 96 | OpenBSD 6.2 March 5, 2018 OpenBSD 6.2 |
101 | It generates "Connection closed by remote host" messages on the consoles | ||
102 | of all the machines it scans if the server is older than version 2.9. | ||
103 | This is because it opens a connection to the ssh port, reads the public | ||
104 | key, and drops the connection as soon as it gets the key. | ||
105 | |||
106 | OpenBSD 6.2 May 2, 2017 OpenBSD 6.2 | ||