Bump LT version.

* configure.ac: Bumb LT version to C21/A1/R0.
--

This is to avoid conflicts with the 1.6 series.  Note that if we add a
new interface to 1.6 we would need to bump age again.
Comment typo fix

--
mpi: Fix a subtle bug setting spurious bits with in mpi_set_bit.

* mpi/mpi-bit.c (_gcry_mpi_set_bit, _gcry_mpi_set_highbit): Clear
allocated but not used bits before resizing.
* tests/t-mpi-bits.c (set_bit_with_resize): New.
--

Reported-by: Martin Sewelies.

This bug is probably with us for many years.  Probably due to
different memory allocation patterns, it did first revealed itself
with 1.6.  It could be the reason for other heisenbugs.

Signed-off-by: Werner Koch <wk@gnupg.org>
Add ChaCha20 stream cipher

* cipher/Makefile.am: Add 'chacha20.c'.
* cipher/chacha20.c: New.
* cipher/cipher.c (cipher_list): Add ChaCha20.
* configure.ac: Add ChaCha20.
* doc/gcrypt.texi: Add ChaCha20.
* src/cipher.h (_gcry_cipher_spec_chacha20): New.
* src/gcrypt.h.in (GCRY_CIPHER_CHACHA20): Add new algo.
* tests/basic.c (MAX_DATA_LEN): Increase to 128 from 100.
(check_stream_cipher): Add ChaCha20 test-vectors.
(check_ciphers): Add ChaCha20.
--

Patch adds Bernstein's ChaCha20 cipher to libgcrypt. Implementation is based
on public domain implementations.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
chacha20: add SSSE3 assembly implementation

* cipher/Makefile.am: Add 'chacha20-ssse3-amd64.S'.
* cipher/chacha20-ssse3-amd64.S: New.
* cipher/chacha20.c (USE_SSSE3): New macro.
[USE_SSSE3] (_gcry_chacha20_amd64_ssse3_blocks): New.
(chacha20_do_setkey): Select SSSE3 implementation if there is HW
support.
* configure.ac [host=x86-64]: Add 'chacha20-ssse3-amd64.lo'.
--

Add SSSE3 optimized implementation for ChaCha20. Based on implementation
by Andrew Moon.

Before (Intel Haswell):

 CHACHA20       |  nanosecs/byte   mebibytes/sec   cycles/byte
     STREAM enc |      1.97 ns/B     483.6 MiB/s      6.31 c/B
     STREAM dec |      1.97 ns/B     484.0 MiB/s      6.31 c/B

After:

 CHACHA20       |  nanosecs/byte   mebibytes/sec   cycles/byte
     STREAM enc |     0.742 ns/B    1284.8 MiB/s      2.38 c/B
     STREAM dec |     0.741 ns/B    1286.5 MiB/s      2.37 c/B

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>
chacha20: add AVX2/AMD64 assembly implementation

* cipher/Makefile.am: Add 'chacha20-avx2-amd64.S'.
* cipher/chacha20-avx2-amd64.S: New.
* cipher/chacha20.c (USE_AVX2): New macro.
[USE_AVX2] (_gcry_chacha20_amd64_avx2_blocks): New.
(chacha20_do_setkey): Select AVX2 implementation if there is HW
support.
(selftest): Increase size of buf by 256.
* configure.ac [host=x86-64]: Add 'chacha20-avx2-amd64.lo'.
--

Add AVX2 optimized implementation for ChaCha20. Based on implementation by
Andrew Moon.

SSSE3 (Intel Haswell):

 CHACHA20       |  nanosecs/byte   mebibytes/sec   cycles/byte
     STREAM enc |     0.742 ns/B    1284.8 MiB/s      2.38 c/B
     STREAM dec |     0.741 ns/B    1286.5 MiB/s      2.37 c/B

AVX2:

 CHACHA20       |  nanosecs/byte   mebibytes/sec   cycles/byte
     STREAM enc |     0.393 ns/B    2428.0 MiB/s      1.26 c/B
     STREAM dec |     0.392 ns/B    2433.6 MiB/s      1.25 c/B

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>