I'm happy to announce a new release of GNU Nettle, a low-level cryptographics library. This release includes a couple of new features and improved performance.
The Nettle home page can be found at https://www.lysator.liu.se/~nisse/nettle/, and the manual at https://www.lysator.liu.se/~nisse/nettle/nettle.html.
The release can be downloaded from
https://ftp.gnu.org/gnu/nettle/nettle-3.5.tar.gz ftp://ftp.gnu.org/gnu/nettle/nettle-3.5.tar.gz https://www.lysator.liu.se/~nisse/archive/nettle-3.5.tar.gz
Regards, /Niels
NEWS for the Nettle 3.5 release
This release adds a couple of new features and optimizations, and deletes or deprecates a few obsolete features. It is *not* binary (ABI) compatible with earlier versions. Except for deprecations listed below, it is intended to be fully source-level (API) compatible with Nettle-3.4.1.
The shared library names are libnettle.so.7.0 and libhogweed.so.5.0, with sonames libnettle.so.7 and libhogweed.so.5.
Changes in behavior:
* Nettle's gcm_crypt will now call the underlying block cipher to process more than one block at a time. This is not a change to the documented behavior, but unfortunately breaks assumptions accidentally made in GnuTLS, up to and including version 3.6.1.
New features:
* Support for CFB8 (Cipher Feedback Mode, processing a single octet per block cipher operation), contributed by Dmitry Eremin-Solenikov.
* Support for CMAC (RFC 4493), contributed by Nikos Mavrogiannopoulos.
* Support for XTS mode, contributed by Simo Sorce.
Optimizations:
* Improved performance of the x86_64 AES implementation using the aesni instructions. Gives a large speedup for operations processing multiple blocks at a time (including CTR mode, GCM mode, and CBC decrypt, but *not* CBC encrypt).
* Improved performance for CTR mode, for the common case of 16-byte block size. Pass more data at a time to underlying block cipher, and fill the counter blocks more efficiently. Extension to also handle GCM mode efficiently contributed by Nikos Mavrogiannopoulos.
* New x86_64 implementation of sha1 and sha256, for processors supporting the sha_ni instructions. Speedup of 3-5 times on affected processors.
* Improved parameters for the precomputation of tables used for ecc signatures. Roughly 10%-15% speedup of the ecdsa sign operation using the secp_256r1, secp_384r1 and secp_521r1 curves, and 25% speedup of ed25519 sign operation, benchmarked on x86_64. Table sizes unchanged, around 16 KB per curve.
* In ARM fat builds, automatically select Neon implementation of Chacha, where possible. Contributed by Yuriy M. Kaminskiy.
Deleted features:
* The header file des-compat.h and everything declared therein has been deleted, as announced earlier. This file provided a subset of the old libdes/ssleay/openssl interface for DES and triple-DES. DES is still supported, via the functions declared in des.h.
* Functions using the old struct aes_ctx have been marked as deprecated. Use the fixed key size interface instead, e.g., struct aes256_ctx, introduced in Nettle-3.0.
* The header file nettle-stdint.h, and corresponding autoconf tests, have been deleted. Nettle now requires that the compiler/libc provides <stdint.h>.
Miscellaneous:
* Support for big-endian ARM systems, contributed by Michael Weiser.
* The programs aesdata, desdata, twofishdata, shadata and gcmdata are no longer built by default. Makefile improvements contributed by Jay Foad.
* The "example" program examples/eratosthenes.c has been deleted.
* The contents of hash context structs, and the deprecated aes_ctx struct, have been reorganized, to enable later optimizations.