NaCl (software)#Implementations

• {{code|crypto_box}}, public-key authenticated encryption. Key agreement happens via X25519; encryption is done by Salsa20-Poly1305.{{cite book|last1=Bernstein|first1=Daniel J.|title=Cryptography in NaCl|date=10 March 2009|url=https://cr.yp.to/highspeed/naclcrypto-20090310.pdf|access-date=8 February 2016|archive-url=https://web.archive.org/web/20170325015935/https://cr.yp.to/highspeed/naclcrypto-20090310.pdf|archive-date=25 March 2017|url-status=live}}
• {{code|crypto_scalarmult}}, scalar multiplication on X25519. This function can be used for elliptic-curve Diffie–Hellman.
• {{code|crypto_sign}}, signatures using Ed25519 and SHA-512.

• {{code|crypto_secretbox}}, private-key authenticated encryption using Salsa20-Poly1305.
• {{code|crypto_stream}}, encryption using Salsa20, XSalsa20, or AES.
• {{code|crypto_auth}}, authentication using HMAC-SHA-512-256.
• {{code|crypto_onetimeauth}}, single-message authentication using Poly1305.

• {{code|crypto_hash}}, hashing using SHA-512 or SHA-256{{cite web |url=https://nacl.cr.yp.to/hash.html |title=Hashing: crypto_hash |date=2010-08-30 |access-date=2015-11-14}}
• {{code|crypto_verify}}, string comparison in constant time.{{cite web |title=String comparison: crypto_verify |url=https://nacl.cr.yp.to/verify.html |website=nacl.cr.yp.to |access-date=19 January 2024}}

The reference implementation is written in C, often incorporating inline assembly routines. C++ support is implemented as a wrapper. A Python wrapper was planned,{{cite web| url=https://nacl.cr.yp.to/internals.html | title = NaCl Internals}} but is not part of the latest (20110221) release. The home page, last updated in 2016, mentions prototype wrappers.

The reference NaCl implementation has a variety of programming language bindings, such as PHP{{cite web |url=https://github.com/Gasol/pecl-nacl | title= NaCl PHP Extension | publisher=Github| date= 2019-06-14 }} and Tcl.{{cite web|url=http://wiki.tcl.tk/47681 | title= Tclers Wiki - NaCl for Tcl}}{{third-party inline|date=July 2016}}

Libsodium is an API-compatible fork of reference NaCl created in 2013. It is "installable and packageable", or in other words can be compiled into a dynamic library and installed as a software package thanks to the addition of build files (NaCl had none). It is also "portable and cross-compilable".{{cite web |last1=Denis |first1=Frank |title=libsodium: A modern, portable, easy to use crypto library. |website=GitHub |url=https://github.com/jedisct1/libsodium |date=18 January 2024}}

As libsodium can be dynamically linked, it serves as the basis for a number of bindings in languages such as Pharo,{{Cite web|url=http://smalltalkhub.com/tonyg/Crypto-Nacl/|title=SmalltalkHub repository}} Perl 5,{{cite web|url=https://metacpan.org/pod/Crypt::NaCl::Sodium|title=Crypt::NaCl::Sodium}} and Python.{{cite web |title=pyca/pynacl |url=https://github.com/pyca/pynacl |author=((Python Cryptographic Authority))|website=GitHub |date=18 January 2024 |quote=PyNaCl is a Python binding to libsodium, which is a fork of the Networking and Cryptography library.}}{{cite web |title=Bindings for other languages |url=https://doc.libsodium.org/bindings_for_other_languages |website=libsodium}}

libsodium also extends the NaCl API with new algorithms (e.g. BLAKE2,{{cite web|url=https://download.libsodium.org/doc/hashing/generic_hashing.html#algorithm-details |date=2017-12-13 |access-date=2018-05-19|title=Generic hashing }} ChaCha20-Poly1305, AEGIS){{cite web |title=AEAD constructions |url=https://doc.libsodium.org/secret-key_cryptography/aead |website=libsodium}} and new classes of functions (e.g. secure memory, random number generation, short-input hashing,{{cite web |title=Short-input hashing |url=https://doc.libsodium.org/hashing/short-input_hashing |website=libsodium}} password hashing and key derivation).

In 2013, the NaCl team and three others released TweetNaCl, a condensed implementation of NaCl's 25 functions that fits in the size of 100 tweets (140 symbols each).{{cite web|url=https://tweetnacl.cr.yp.to/ | title=TweetNaCl|author1=Daniel J. Bernstein

|author2=Bernard van Gastel

|author3=Wesley Janssen

|author4=Tanja Lange

|author5=Peter Schwabe

|author6=Sjaak Smetsers|date=2013}}

TweetNaCl has been used as the basis of ports including TweetNaCl.js{{cite web|url=https://tweetnacl.js.org/ | title=TweetNaCl.js}} and TweetNaCl-Java.{{cite web|url=https://github.com/InstantWebP2P/tweetnacl-java/ | title=TweetNaCl-Java| website=GitHub}} It has also been rewritten in the SPARK Ada subset as SPARKNaCl, which the authors describe as "(unlike TweetNaCl) readable owing to the large number of explanatory comments and contracts in the code."{{cite web|url=https://www.github.com/rod-chapman/SPARKNaCl/ | title=SPARKNaCl| website=GitHub}}

• RustCrypto - a popular set of pure-Rust crypto libraries that includes an NaCl compatibility layer.
• dryoc — a pure-Rust cryptography library implementing the libsodium/NaCl API with support for protected memory.{{cite web|url=https://github.com/brndnmtthws/dryoc | title=Don't Roll Your Own Crypto (dryoc): pure-Rust, hard to misuse cryptography library | website=GitHub }}
• Monocypher — a rewrite of NaCl in C. Aims to have the speed of reference NaCl and the size of TweetNaCl.{{cite web |last1=Vaillant |first1=Loup |title=LoupVaillant/Monocypher |website=GitHub |url=https://github.com/LoupVaillant/Monocypher |date=17 January 2024}}

• The use of the term salt in cryptography
• Comparison of cryptography libraries
• List of free and open-source software packages

{{Reflist|30em}}

• {{Official website|https://nacl.cr.yp.to/}}

Category:Public-domain software

Category:Cryptographic software

Category:2008 software