Libgcrypt 1.8.x is required for a large amount of decryption
support and is the current LTS version of libgcrypt. The 1.6 and
1.7 series have been end-of-life since 2017-06-30 and 2019-06-30,
respectively.
The Linux distributions that have versions of libgcrypt before 1.8.0
are nearing or at end of support (RHEL7, SLES 12, Debian stretch,
Ubuntu 16.04LTS) and can be supported by the Wireshark 3.6 LTS release
series.
Remove an enormous amount of ifdefs based on libgcrypt versions
1.6.0, 1.7.0, and 1.8.0. There will be a second pass for the
commons defines HAVE_LIBGCRYPT_AEAD, HAVE_LIBGCRYPT_CHACHA20, and
HAVE_LIBGCRYPT_CHACHA20_POLY1305, which are now always defined.
The ISAKMP dissector has some comments noting that some workarounds
were used for libgcrypt 1.6 that aren't needed with 1.7; perhaps
that could be updated now.
The libwsutil symbols file contains two public symbols which depend on
Libgcrypt 1.7.0. As the version included with Ubuntu 16.04 is too old,
building a Debian package fails due to missing two curve25519 symbols.
Add stub implementations as workaround.
Change-Id: Ie39e784e9e631750b5269d038772496565b2dce8
Reviewed-on: https://code.wireshark.org/review/33780
Petri-Dish: Peter Wu <peter@lekensteyn.nl>
Tested-by: Petri Dish Buildbot
Reviewed-by: Anders Broman <a.broman58@gmail.com>
The WireGuard dissector will need X25519 to enable decryption, add a
Gcrypt implementation that implements the NaCl/Sodium interface.
While inspired by the MPI example in t-cv25519.c, note subtle but
important correctness/interoperability fixes: add a check for infinity
(gcry_mpi_ec_get_affine) and handle short values from gcry_mpi_print.
The last issue is ugly, perhaps the high level API (gcry_pk_decrypt)
should be used instead (which < 2% slower than this MPI implementation).
(Both issues were found through fuzzing.)
As for alternative options, Sodium is superior but would be a new
dependency. For some older performance and usability notes (comparing
crypto_scalarmult_curve25519_base (note "_base") against others), see
https://lists.gnupg.org/pipermail/gcrypt-devel/2018-July/004532.html
Performance comparison on Ubuntu 18.04 (i7-3770) between Sodium 1.0.16
against Gcrypt 1.8.3 and Gcrypt 86e5e06a (git master, future 1.9.x) by
computing 65536 times X25519(1, 8) via crypto_scalarmult_curve25519:
Sodium (sandy2x): 1.4x faster than ref10
Sodium (ref10): 1 (baseline)
Gcrypt (git): 5x slower than ref10, 7x slower than sandy2x
Gcrypt (1.8.3): 17x ref10, 24x sandy2x (took 65 seconds)
Change-Id: Ia54e73cc3cc469a6697554729aff4edd19f55630
Ping-Bug: 15011
Reviewed-on: https://code.wireshark.org/review/28987
Reviewed-by: Anders Broman <a.broman58@gmail.com>
João Valverde