Version 17 of NaCl - Networking and Cryptography library (pronounced "salt")

Updated 2016-08-22 16:53:15 by EMJ

ALX 2016-08-19 17:05:00:

See http://sourceforge.net/projects/tclsnippets/files/nacl/ for releases, source, ...

The package has TEA Tcl Extension Architecture and has been tested under AIX, Linux, Mac OS X and Windows XP - 7.

This package is licensed unter BSD-3.


AMG: "NaCl" also refers to Google Chrome's Native Client sandbox. See NaTcl.

NaCl is an unfortunate choice of name, it conflicts with Google's "Native Client" (NaCl) library https://www.chromium.org/nativeclient which could well use a Tcl interface to enable full standard Tcl to run "native" within a browser at normal compiled speeds, and as such, we might prefer to rename this newer piece of software since Native Client has been around a while and probably has prior claim. Larry Smith

(2016-08-22) Note: according to Wikipedia, the NaCl crypto library has prior claim: 2008 vs. 2011 for Google's Native Client.

EMJ - 2016-08-22: See also http://nacl.cr.yp.to/ .


NAME

nacl - tcl package for Networking and Cryptography library (pronounced "salt")

SYNOPSIS

nacl::info
nacl::rcsid
nacl::randombytes names
nacl::randombytes source ?random|urandom|secrandomcopybytes|cryptgenrandom|default?
nacl::randombytes lengthValue
nacl::randombytes box ?-nonce?
nacl::randombytes scalarmult ?-scalar|-group?
nacl::randombytes secretbox ?-nonce|-key?
nacl::randombytes stream ?-nonce|-key?
nacl::randombytes auth ?-key?
nacl::randombytes onetimeauth ?-key?

Public-key cryptography

nacl::box info
nacl::box keypair publicKeyVariable secretKeyVariable
nacl::box cipherVariable messageValue nonceValue publicKeyValue secretKeyValue
nacl::box open messageVariable cipherValue nonceValue publicKeyValue secretKeyValue
nacl::scalarmult info
nacl::scalarmult resultVariable scalarValue groupValue
nacl::scalarmult base resultVariable scalarValue
nacl::sign info
nacl::sign keypair publicKeyVariable secretKeyVariable
nacl::sign signedVariable messageValue secretKeyValue
nacl::sign verify messageVariable signedValue publicKeyValue

Secret-key cryptography

nacl::secretbox info
nacl::secretbox cipherVariable messageValue nonceValue keyValue
nacl::secretbox open messageVariable cipherValue nonceValue keyValue
nacl::stream info
nacl::stream generate cipherVariable nonceValue keyValue
nacl::stream cipherVariable messageValue nonceValue keyValue
nacl::auth info
nacl::auth ?-hmac256|-hmac512256? authVariable messageValue keyValue
nacl::auth verify -hmac256|-hmac512256 authValue messageValue keyValue
nacl::onetimeauth info
nacl::onetimeauth authVariable messageValue keyValue
nacl::onetimeauth verify authValue messageValue keyValue

Low-level functions

nacl::hash info
nacl::hash ?-sha256|-sha512? hashVariable messageValue

DESCRIPTION

NaCl (pronounced "salt") is a new easy-to-use high-speed software library for network communication, encryption, decryption, signatures, etc. NaCl's goal is to provide all of the core operations needed to build higher-level cryptographic tools. Of course, other libraries already exist for these core operations. NaCl advances the state of the art by improving security, by improving usability, and by improving speed.

Key features

No data flow from secrets to load addresses. No data flow from secrets to branch conditions. No padding oracles. Centralizing randomness. Avoiding unnecessary randomness. Extremely high speed.

Functions supported

Simple NaCl applications need only six high-level NaCl functions: crypto_box for public-key authenticated encryption; crypto_box_open for verification and decryption; crypto_box_keypair to create a public key in the first place; and similarly for signatures crypto_sign, crypto_sign_open, and crypto_sign_keypair.

A minimalist implementation of the NaCl API would provide just these six functions. TweetNaCl is more ambitious, supporting all 25 of the NaCl functions listed below, which as mentioned earlier are all of the C NaCl functions used by applications. This list includes all of NaCl's "default" primitives except for crypto_auth_hmacsha512256, which was included in NaCl only for compatibility with standards and is superseded by crypto_onetimeauth.

The Ed25519 signature system has not yet been integrated into NaCl, since the Ed25519 software has not yet been fully audited; NaCl currently provides an older signature system. However, NaCl has announced that it will transition to Ed25519, so TweetNaCl provides Ed25519.

Public-key cryptography

  • Authenticated encryption using Curve25519, Salsa20, and Poly1305
    • crypto_box = crypto_box_curve25519xsalsa20poly1305
    • crypto_scalarmult = crypto_scalarmult_curve25519
  • Signatures using Ed25519
    • crypto_sign = crypto_sign_ed25519

Secret-key cryptography

  • Authenticated encryption using Salsa20 and Poly1305
    • crypto_secretbox = crypto_secretbox_xsalsa20poly1305
  • Encryption using Salsa20
    • crypto_stream = crypto_stream_xsalsa20
  • Authentication using HMAC-SHA-512-256
    • crypto_auth_hmacsha256_ref, crypto_auth_hmacsha512256_ref
  • One-time authentication using Poly1305
    • crypto_onetimeauth = crypto_onetimeauth_poly1305

Low-level functions

  • Hashing using SHA-512 or SHA-256
    • crypto_hash_sha256_ref, crypto_hash = crypto_hash_sha512

EXAMPLES

Public-key cryptography authenticated encryption using nacl::box

package require nacl

nacl::box keypair pub1 sec1
nacl::box keypair pub2 sec2
set nonce [nacl::randombytes box -nonce]
set message {My Secret Message}

if {[nacl::box encrypted $message $nonce $pub2 $sec1] == 0} {
  if {[nacl::box open decrypted $encrypted $nonce $pub1 $sec2] == 0} {
    puts "message decrypted = '$decrypted'"
  }
}

Public-key cryptography signatures using nacl::sign

package require nacl

nacl::sign keypair pub sec
set message {My Message}

if {[nacl::sign encrypted $message $sec] == 0} {
  if {[nacl::sign verify decrypted $encrypted $pub] == 0} {
    puts "signed message decrypted = '$decrypted'"
  }
}

Secret-key cryptography authenticated encryption using nacl::secretbox

package require nacl

set key [nacl::randombytes secretbox -key]
set nonce [nacl::randombytes secretbox -nonce]
set message {My Secret Message}

if {[nacl::secretbox encrypted $message $nonce $key] == 0} {
  if {[nacl::secretbox open decrypted $encrypted $nonce $key] == 0} {
    puts "message decrypted = '$decrypted'"
  }
}

Secret-key cryptography encryption using nacl::stream

package require nacl

set key [nacl::randombytes stream -key]
set nonce [nacl::randombytes stream -nonce]
set message {My Secret Message}

if {[nacl::stream encrypted $message $nonce $key] == 0} {
  if {[nacl::stream decrypted $encrypted $nonce $key] == 0} {
    puts "message decrypted = '$decrypted'"
  }
}

Secret-key cryptography authentication using nacl::auth

package require nacl

set key [nacl::randombytes auth -key]
set message {My Message}

if {[nacl::auth -hmac512256 auth $message $key] == 0} {
  if {[nacl::auth verify -hmac512256 $auth $message $key] == 0} {
    puts {authentication OK}
  }
}

Secret-key cryptography one-time authentication using nacl::onetimeauth

package require nacl

set key [nacl::randombytes onetimeauth -key]
set message {My Message}

if {[nacl::onetimeauth auth $message $key] == 0} {
  if {[nacl: onetimeauth verify $auth $message $key] == 0} {
    puts {one-time authentication OK}
  }
}

Hashing using nacl::hash

package require nacl

if {[nacl::hash -sha256 hash {NaCl does SHA256}] == 0} {
}

or

package require nacl

if {[nacl::hash -sha512 hash {NaCl does SHA512}] == 0} {
}

SEE ALSO

https://nacl.cr.yp.to 20110221
https://tweetnacl.cr.yp.to 20140427

LEGAL NOTICE

Copyright (C) 2016 Alexander Schoepe, Bochum, DE

NaCl and TweetNaCl crypto library are public domain and the Tcl package BSD-3 license

Contributors (alphabetical order)
Daniel J. Bernstein, University of Illinois at Chicago and Technische Universiteit Eindhoven
Bernard van Gastel, Radboud Universiteit Nijmegen
Wesley Janssen, Radboud Universiteit Nijmegen
Tanja Lange, Technische Universiteit Eindhoven
Peter Schwabe, Radboud Universiteit Nijmegen
Sjaak Smetsers, Radboud Universiteit Nijmegen