1SSH-KEYSIGN(8) BSD System Manager's Manual SSH-KEYSIGN(8)
2
4 ssh-keysign — ssh helper program for host-based authentication
5
7 ssh-keysign
8
10 ssh-keysign is used by ssh(1) to access the local host keys and generate
11 the digital signature required during host-based authentication.
12
13 ssh-keysign is disabled by default and can only be enabled in the global
14 client configuration file /etc/ssh/ssh_config by setting EnableSSHKeysign
15 to “yes”.
16
17 ssh-keysign is not intended to be invoked by the user, but from ssh(1).
18 See ssh(1) and sshd(8) for more information about host-based authentica‐
19 tion.
20
22 /etc/ssh/ssh_config
23 Controls whether ssh-keysign is enabled.
24
25 /etc/ssh/ssh_host_dsa_key
26 /etc/ssh/ssh_host_ecdsa_key
27 /etc/ssh/ssh_host_ed25519_key
28 /etc/ssh/ssh_host_rsa_key
29 These files contain the private parts of the host keys used to
30 generate the digital signature. They should be owned by root,
31 readable only by root, and not accessible to others. Since they
32 are readable only by root, ssh-keysign must be set-uid root if
33 host-based authentication is used.
34
35 /etc/ssh/ssh_host_dsa_key-cert.pub
36 /etc/ssh/ssh_host_ecdsa_key-cert.pub
37 /etc/ssh/ssh_host_ed25519_key-cert.pub
38 /etc/ssh/ssh_host_rsa_key-cert.pub
39 If these files exist they are assumed to contain public certifi‐
40 cate information corresponding with the private keys above.
41
43 SSH_USE_STRONG_RNG
44 The reseeding of the OpenSSL random generator is usually done
45 from /dev/urandom. If the SSH_USE_STRONG_RNG environment vari‐
46 able is set to value other than 0 the OpenSSL random generator is
47 reseeded from /dev/random. The number of bytes read is defined
48 by the SSH_USE_STRONG_RNG value. Minimum is 14 bytes. This set‐
49 ting is not recommended on the computers without the hardware
50 random generator because insufficient entropy causes the connec‐
51 tion to be blocked until enough entropy is available.
52
54 ssh(1), ssh-keygen(1), ssh_config(5), sshd(8)
55
57 ssh-keysign first appeared in OpenBSD 3.2.
58
60 Markus Friedl <markus@openbsd.org>
61
62BSD June 21, 2019 BSD