Dropbear 2018.76

[Matt Johnston]

Hi all,

Dropbear 2018.76 is released. As well as the usual
improvements and bugfixes this release simplifies 
local configuration options.
You will probably need to adjust your build configuration.

Rather than modifying options.h, local options are now
placed in localoptions.h where they will override defaults. 
The header file default_options.h lists the available
options similar to the old options.h - it should be left
unmodified.

There are a few other deprecations/changes to take note of.

Cheers,
Matt

https://matt.ucc.asn.au/dropbear/dropbear.html
https://dropbear.nl/mirror/dropbear.html

2018.76 - 27 February 2018

= = = Configuration/compatibility changes
  IMPORTANT
  Custom configuration is now specified in local_options.h rather than options.h
  Available options and defaults can be seen in default_options.h

  To migrate your configuration, compare your customised options.h against the
  upstream options.h from your relevant version. Any customised options should
  be put in localoptions.h

- "configure --enable-static" should now be used instead of "make STATIC=1"
  This will avoid 'hardened build' flags that conflict with static binaries

- Set 'hardened build' flags by default if supported by the compiler.
  These can be disabled with configure --disable-harden if needed.
  -Wl,-pie
  -Wl,-z,now -Wl,-z,relro
  -fstack-protector-strong
  -D_FORTIFY_SOURCE=2
  # spectre v2 mitigation
  -mfunction-return=thunk
  -mindirect-branch=thunk

  Spectre patch from Loganaden Velvindron

- "dropbear -r" option for hostkeys no longer attempts to load the default
  hostkey paths as well. If desired these can be specified manually. 
  Patch from CamVan Nguyen

- group1-sha1 key exchange is disabled in the server by default since
  the fixed 1024-bit group may be susceptible to attacks

- twofish ciphers are now disabled in the default configuration

- Default generated ECDSA key size is now 256 (rather than 521) 
  for better interoperability

- Minimum RSA key length has been increased to 1024 bits

= = = Other features and fixes

- Add runtime -T max_auth_tries option from Kevin Darbyshire-Bryant

- Add 'dbclient -J &fd' to allow dbclient to connect over an existing socket.
  See dbclient manpage for a socat example. Patch from Harald Becker

- Add "-c forced_command" option. Patch from Jeremy Kerr

- Restricted group -G option added with patch from stellarpower

- Support server-chosen TCP forwarding ports, patch from houseofkodai

- Allow choosing outgoing address for dbclient with -b [bind_address][:bind_port]
  Patch from houseofkodai

- Makefile will now rebuild object files when header files are modified

- Add group14-256 and group16 key exchange options

- curve25519-sha256 also supported without @libssh.org suffix

- Update bundled libtomcrypt to 1.18.1, libtommath to 1.0.1
  This fixes building with some recent versions of clang

- Set PAM_RHOST which is needed by modules such as pam_abl

- Improvements to DSS and RSA public key validation, found by OSS-Fuzz. 

- Don't exit when an authorized_keys file has malformed entries. Found by OSS-Fuzz

- Fix null-pointer crash with malformed ECDSA or DSS keys. Found by OSS-Fuzz

- Numerous code cleanups and small issues fixed by Francois Perrad

- Test for pkt_sched.h rather than SO_PRIORITY which was problematic with some musl
  platforms. Reported by Oliver Schneider and Andrew Bainbridge

- Fix some platform portability problems, from Ben Gardner

- Add EXEEXT filename suffix for building dropbearmulti, from William Foster

- Support --enable-<option> properly for configure, from Stefan Hauser

- configure have_openpty result can be cached, from Eric Bénard

- handle platforms that return close() < -1 on failure, from Marco Wenzel

- Build and configuration cleanups from Michael Witten

- Fix libtomcrypt/libtommath linking order, from Andre McCurdy

- Fix old Linux platforms that have SYS_clock_gettime but not CLOCK_MONOTONIC

- Update curve25519-donna implementation to current version