Add support for disabling SSH signature algorithms

XMLWordPrintable

    • RtB - Service ops & Tech entropy

      When running the following ssh command with verbose log parameter:

      ssh -vvv -p 7999 git@bitbucket-base-url
      

      We can see in the server KEXINIT proposal, that the "ssh-rsa" host key is available. We would like to get this removed from the available host keys and only allow RSA2.

      debug2: peer server KEXINIT proposal
      debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,curve448-sha512,ecdh-sha2-nistp521,ecdh-sha2-nistp384,ecdh-sha2-nistp256,diffie-hellman-group-exchange-sha256,diffie-hellman-group18-sha512,diffie-hellman-group17-sha512,diffie-hellman-group16-sha512,diffie-hellman-group15-sha512,diffie-hellman-group14-sha256,ext-info-s,kex-strict-s-v00@openssh.com
      debug2: host key algorithms: rsa-sha2-512,rsa-sha2-256,ssh-rsa
      debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
      debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com
      debug2: MACs ctos: hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
      debug2: MACs stoc: hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
      

            Assignee:
            Brent P
            Reporter:
            Pablo Silva
            Votes:
            2 Vote for this issue
            Watchers:
            8 Start watching this issue

              Created:
              Updated:
              Resolved: