monocypher-cr
monocypher.cr
Crystal wrapper for a cryptographic library Monocypher (Official site, Github page)
Note: Sources of Monocypher (version 3.1.2 currently) are included in the shard and will be linked statically with application. On the other hand, if libmonocypher.so is present in library paths at the time of compilation, linker seems to prefer dynamic linking.
Also included is the standard ED25519 cryptography which Monocypher supplies as an optional component.
Installation
- Add this to your application's
shard.yml
:
dependencies:
monocypher:
github: konovod/monocypher
-
shards update
will install a shard and compile Monocypher static library. So you need clang or gcc.2.1. On Windows: currently, shards way isn't supported, but you can compile monocypher manually using following commands(from visual studio development prompt):
cd ext cl /c /EHsc /O2 /MT monocypher.c cl /c /EHsc /O2 /MT monocypher-ed25519.c lib monocypher.obj monocypher-ed25519.obj
and then copy
monocypher.lib
file to where your Crystal looks for lib files.
Usage
- The wrapper is created with an additional requirement - using a crypto library for encrypting/decrypting of messages shouldn't cause heap allocations. So it doesn't provide function
plaintext = Crypto.unlock(ciphertext, key)
(as it will require allocation ofplaintext
every time message being decrypted). Instead it provideCrypto.decrypt(key: Bytes, input: Bytes, output: Bytes)
function that will operate on preallocated buffers. - Most functions receive named arguments. This makes code slightly more verbose, but hopefully will prevent messing up arguments order.
Example of usage:
require "monocypher"
channel = Channel(Bytes).new # should be fixed size in real apps
alice_secret = Crypto::SecretKey.new
alice_public = Crypto::PublicKey.new(secret: alice_secret)
bob_secret = Crypto::SecretKey.new
bob_public = Crypto::PublicKey.new(secret: bob_secret)
# sender part
spawn do
alice_shared = Crypto::SymmetricKey.new(our_secret: alice_secret, their_public: bob_public)
message = "This is a test message русский текст"
plaintext = message.to_slice
ciphertext = Bytes.new(plaintext.size + Crypto::OVERHEAD_SYMMETRIC)
Crypto.encrypt(key: alice_shared, input: plaintext, output: ciphertext)
channel.send ciphertext
end
# receiver part
bob_shared = Crypto::SymmetricKey.new(our_secret: bob_secret, their_public: alice_public)
ciphertext = channel.receive
result = Bytes.new(ciphertext.size - Crypto::OVERHEAD_SYMMETRIC)
Crypto.decrypt(key: bob_shared, input: ciphertext, output: result)
puts String.new(result)
check spec
dir for more usage examples (TODO - other examples)
Hashes
Monocypher includes functions for cryptographic hashes Blake2b and SHA-512, they are wrapped with simple crystal functions
Crypto.sha512("".to_slice).hexstring
# "cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e"
Crypto.blake2b("abc".to_slice, key: "".to_slice, hash_size: 64).hexstring
# same as Crypto.blake2b("abc".to_slice).hexstring
# ba80a53f981c4d0d6a2797b69f12f6e94c212f14685ac4b74b12bb6fdbffa2d17d87c5392aab792dc252d5de4533cc9518d38aa8dbf1925ab92386edd4009923
There is also Digest
interface used in Crystal stdlib:
digest = Crypto::Digest::SHA512.new
digest << "123"
digest.final.hexstring # "3c9909afec25354d551dae21590bb26e38d53f2173b8d3dc3eee4c047e7ab1c1eb8b85103e3be7ba613b31bb5c9c36214dc9f14a42fd7a2fdb84856bca5c44c2"
digest = Crypto::Digest::Blake2b.new
digest << "123"
digest.final.hexstring # "ba80a53f981c4d0d6a2797b69f12f6e94c212f14685ac4b74b12bb6fdbffa2d17d87c5392aab792dc252d5de4533cc9518d38aa8dbf1925ab92386edd4009923"
monocypher-cr
- 0
- 0
- 0
- 0
- 1
- over 2 years ago
- February 28, 2022
MIT License
Thu, 07 Nov 2024 14:24:41 GMT