OpenSSH 9.8

  Future deprecation notice
  =========================
  
  OpenSSH plans to remove support for the DSA signature algorithm in
  early 2025. This release disables DSA by default at compile time.
  
  DSA, as specified in the SSHv2 protocol, is inherently weak - being
  limited to a 160 bit private key and use of the SHA1 digest. Its
  estimated security level is only 80 bits symmetric equivalent.
  
  OpenSSH has disabled DSA keys by default since 2015 but has retained
  run-time optional support for them. DSA was the only mandatory-to-
  implement algorithm in the SSHv2 RFCs, mostly because alternative
  algorithms were encumbered by patents when the SSHv2 protocol was
  specified.
  
  This has not been the case for decades at this point and better
  algorithms are well supported by all actively-maintained SSH
  implementations. We do not consider the costs of maintaining DSA
  in OpenSSH to be justified and hope that removing it from OpenSSH
  can accelerate its wider deprecation in supporting cryptography
  libraries.
  
  This release, and its deactivation of DSA by default at compile-time,
  marks the second step in our timeline to finally deprecate DSA. The
  final step of removing DSA support entirely is planned for the first
  OpenSSH release of 2025.
  
  Potentially-incompatible changes
  --------------------------------
  
   * all: as mentioned above, the DSA signature algorithm is now
     disabled at compile time.
  
   * sshd(8): the server will now block client addresses that
     repeatedly fail authentication, repeatedly connect without ever
     completing authentication or that crash the server. See the
     discussion of PerSourcePenalties below for more information.
     Operators of servers that accept connections from many users, or
     servers that accept connections from addresses behind NAT or
     proxies may need to consider these settings.
  
   * sshd(8): the server has been split into a listener binary, sshd(8),
     and a per-session binary "sshd-session". This allows for a much
     smaller listener binary, as it no longer needs to support the SSH
     protocol. As part of this work, support for disabling privilege
     separation (which previously required code changes to disable) and
     disabling re-execution of sshd(8) has been removed. Further
     separation of sshd-session into additional, minimal binaries is
     planned for the future.
  
   * sshd(8): several log messages have changed. In particular, some
     log messages will be tagged with as originating from a process
     named "sshd-session" rather than "sshd".
  
   * ssh-keyscan(1): this tool previously emitted comment lines
     containing the hostname and SSH protocol banner to standard error.
     This release now emits them to standard output, but adds a new
     "-q" flag to silence them altogether.
  
   * sshd(8): (portable OpenSSH only) sshd will no longer use argv[0]
     as the PAM service name. A new "PAMServiceName" sshd_config(5)
     directive allows selecting the service name at runtime. This
     defaults to "sshd". bz2101