See below for the security settings for the SSH service on PKI Hub nodes.
Supported SSH version
The SSH service of the PKI Hub nodes supports SSH version 2.0 (SSHv2).
Supported authentication mechanisms:
The SSH service on PKI Hub nodes supports authentication with either a password that meets the Password policy CIS benchmarks or a public key supporting the following algorithms.
Algorithm | Key type | Key size |
|---|---|---|
ssh-ed25519 | Ed25519 | 256 bits |
ecdsa-sha2-nistp256 | ECDSA P-256 | 256 bits |
ecdsa-sha2-nistp384 | ECDSA P-384 | 384 bits |
ecdsa-sha2-nistp521 | ECDSA P-521 | 521 bits |
rsa-sha2-512, rsa-sha2-256 | RSA | 2048 bits minimum |
RSA keys:
- Are rejected by the system-wide cryptographic policy when shorter than 2048 bits
- Are always verified with SHA-256 or SHA-512, never with SHA-1, regardless of the algorithm label stored in the key file.
Supported key exchange algorithms
The SSH service of the PKI Hub nodes supports the following key exchange algorithms.
curve25519-sha256curve25519-sha256@libssh.orgecdh-sha2-nistp256ecdh-sha2-nistp384ecdh-sha2-nistp521diffie-hellman-group-exchange-sha256diffie-hellman-group16-sha512diffie-hellman-group18-sha512Supported encryption algorithms
The SSH service of the PKI Hub nodes supports the following encryption algorithms.
aes256-gcm@openssh.comaes128-gcm@openssh.comchacha20-poly1305@openssh.comaes256-ctraes128-ctrMessage authentication code algorithms
The following AEAD ciphers provide integrity protection themselves and do not negotiate a separate MAC algorithm.
es256-gcm@openssh.comaes128-gcm@openssh.comchacha20-poly1305@openssh.com For the remaining ciphers, the following MAC algorithms are supported.
hmac-sha2-512-etm@openssh.comhmac-sha2-256-etm@openssh.comumac-128-etm@openssh.comhmac-sha2-512hmac-sha2-256umac-128@openssh.comHost key algorithms
The appliance generates three host keys on first boot.
Algorithm | Key type | Key size |
|---|---|---|
ssh-ed25519 | Ed25519 | 256 bits |
ecdsa-sha2-nistp256 | ECDSA P-256 | 256 bits |
rsa-sha2-512, rsa-sha2-256 | RSA | 3072 bits |