GNU Nettle 3.0 is a major update to the library that breaks ABI compatibility with earlier versions of Nettle but is "mostly" source-level API compatible. Besides fixing a number of bugs and reworking some library interfaces, new features to Nettle 3.0 include:
- Support for Poly1305-AES MAC.
- Support for the ChaCha stream cipher and experimental ChaCha-Poly1305 AEAD mode support.
- Support for the EAX and CCM modes.
- New x86_64 assembly for GCM and MD5 to provide 10~20% performance speed-ups.
Nettle is designed to be very versatile as a low-level crypto library and to fit into most any application. Nettle can be interfaced directly from C programs but there's bindings for many different languages -- even Perl, Haskell, and TCL. More information on GNU Nettle 3.0 can be found via the project site. The release announcement for Nettle 3.0 can be found on the info-gnu list.