Re: [PATCH 2/2] ssh_config: Do not set defaults explicitly

[Michael Tremer <michael.tremer@ipfire.org>]

[-- Attachment #1: Type: text/plain, Size: 2581 bytes --]

Reviewed-by: Michael Tremer <michael.tremer(a)ipfire.org>

> On 20 Jan 2020, at 20:05, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> ---
> config/ssh/ssh_config | 27 +++++++++++++--------------
> 1 file changed, 13 insertions(+), 14 deletions(-)
> 
> diff --git a/config/ssh/ssh_config b/config/ssh/ssh_config
> index 2abfae6d1..2e2ee60c3 100644
> --- a/config/ssh/ssh_config
> +++ b/config/ssh/ssh_config
> @@ -1,33 +1,32 @@
> -# OpenSSH client configuration
> +# OpenSSH client configuration file for IPFire
> #
> -# set some basic hardening options for all connections
> +# The full documentation is available at: https://man.openbsd.org/ssh_config
> +#
> +
> +# Set some basic hardening options for all connections
> Host *
> -        # disable Roaming as it is known to be vulnerable
> +        # Disable Roaming as it is known to be vulnerable
>         UseRoaming no
> 
> -        # only use secure crypto algorithm
> +        # Only use secure crypto algorithms
>         KexAlgorithms curve25519-sha256(a)libssh.org,diffie-hellman-group-exchange-sha256
>         Ciphers chacha20-poly1305(a)openssh.com,aes256-gcm(a)openssh.com,aes128-gcm(a)openssh.com,aes256-ctr,aes192-ctr,aes128-ctr
>         MACs hmac-sha2-512-etm(a)openssh.com,hmac-sha2-256-etm(a)openssh.com,umac-128-etm(a)openssh.com,hmac-sha2-512,hmac-sha2-256,umac-128(a)openssh.com
> 
> -        # always visualise server host keys (has no technical
> -        # effect, but helps to identify key based MITM attacks)
> +        # Always visualise server host keys (but helps to identify key based MITM attacks)
>         VisualHostKey yes
> 
> -        # use SSHFP (might work on some up-to-date networks) to look up host keys
> +        # Use SSHFP (might work on some up-to-date networks) to look up host keys
>         VerifyHostKeyDNS yes
> 
>         # send keep-alive messages to connected server to avoid broken connections
>         ServerAliveInterval 10
>         ServerAliveCountMax 6
> 
> -        # disable X11 forwarding (security risk)
> -        ForwardX11 no
> -
> -        # always check server IP address
> -        CheckHostIP yes
> -
> -        # ensure only allowed authentication methods are used
> +        # Ensure only allowed authentication methods are used
>         PreferredAuthentications publickey,keyboard-interactive,password
> 
> +	# Prevent information leak by hashing ~/.ssh/known_hosts
> +	HashKnownHosts yes
> +
> # EOF
> -- 
> 2.16.4
>