https://github.com/geocar/qsalt

NaCL bindings for Q/KDB
https://github.com/geocar/qsalt

Last synced: about 1 month ago
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NaCL bindings for Q/KDB

• Host: GitHub
• URL: https://github.com/geocar/qsalt
• Owner: geocar
• Created: 2015-12-02T19:57:10.000Z (about 9 years ago)
• Default Branch: master
• Last Pushed: 2016-06-11T14:56:16.000Z (over 8 years ago)
• Last Synced: 2024-08-03T17:12:36.321Z (5 months ago)
• Language: C
• Size: 20.5 KB
• Stars: 2
• Watchers: 5
• Forks: 1
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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• awesome-q - geocar/qsalt

README

        
[NaCL](http://nacl.cr.yp.to/) bindings for q/kdb.

##### Table of Contents  

* [Loading](#loading)

* Public Key

 * [Authenticated Encryption](#public-key-authenticated-encryption)

 * [Signatures](#public-key-signatures)

* Secret Key

 * [Authenticated Encryption](#secret-key-authenticated-encryption)

* Utilities

 * [Hashing](#hashing)

 * [Comparing Strings](#comparing-strings)

* [Building](#building)

##Loading

You can load qsalt with:

    .qsalt:@[`qsalt 2:(`qsalt;1);0]

##Public Key Authenticated Encryption

Generate (public;private) keypair:

    alice:.qsalt.pkey`

    bob:.qsalt.pkey`

Alice creates a ciphertext message for Bob:

    message:.qsalt.pencrypt[(.qsalt.nonce`;"this is secret");bob 0;alice 1]

Bob decodes the ciphertext message:

    .qsalt.pdecrypt[message;alice 0;bob 1]

If the ciphertext has been corrupted or was not created by Alice, then null will be returned.

##Public Key Signatures

Generate (public;private) keypair:

    alice:.qsalt.newkey`

    bob:.qsalt.newkey`

Alice signs a message for Bob. Note that the message is not encrypted.

    message:.qsalt.sign["this is verified";alice 1]

Bob then verifies the signature:

    .qsalt.verify[message;alice 0]

If the signature is invalid, then null will be returned.

##Secret Key Authenticated Encryption

There are several ways to generate a secret key; it can be any 32 random bytes:

    secret:.qsalt.random32`

Encrypting a message requires a nonce; this nonce must not be reused:

    message:.qsalt.sencrypt[(.qsalt.nonce`;"this is also secret");secret]

Decrypting the message also verifies it:

    .qsalt.sdecrypt[message;secret]

If the message was altered, then null will be returned.

##Hashing

Calculates the SHA512 hash of a string/bytearray:

    .qsalt.hash "whatever"

##Comparing Strings

`.qsalt.cmp16` and `.qsalt.cmp32` are constant-time comparison functions and should be used for comparing byte-strings.

    .qsalt.cmp16["this is sixteen!";"this is sixteen!"]

    .qsalt.cmp16["this is sixteen!";"somethinginvalid"]

# Building

The makefile assumes kdb/q is installed in `$HOME/q` and that you have [k.h](http://kx.com/q/c/c/k.h) installed in `$HOME/q/c`:

    q/c/k.h

qsalt requires NaCL. On Debian systems you can install:

    sudo apt-get install libsodium-dev

then build with:

    make nacl=-lsodium arch=64

Note if you're building for the 32-bit version of KDB you will need:

    sudo apt-get install libsodium-dev:i386

then build with:

    make nacl=-lsodium arch=32

on other systems you install it from [The NaCL homepage](http://nacl.cr.yp.to/install.html); You can unpack it directly into this tree:

    wget http://hyperelliptic.org/nacl/nacl-20110221.tar.bz2

    bunzip2 < nacl-20110221.tar.bz2 | tar -xf -

    (cd nacl-20110221 && ./do)

Then to build:

    make nacl=nacl-20110221/build/*/lib/amd64/libnacl.a

As a convenience, [tweetnacl](tweetnacl.c) is included, and can be used with:

    make nacl=tweetnacl.c arch=32

    make nacl=tweetnacl.c arch=64