Class: Nuckle::Box

Inherits:
Object
  • Object
show all
Defined in:
lib/nuckle/box.rb

Overview

Public-key authenticated encryption: Curve25519-XSalsa20-Poly1305.

Compatible with NaCl crypto_box / libsodium crypto_box_curve25519xsalsa20poly1305.

Constant Summary collapse

NONCEBYTES = 
24
PUBLICKEYBYTES = 
32
PRIVATEKEYBYTES = 
32
BEFORENMBYTES = 
32
MACBYTES = 
16

Instance Method Summary collapse

Constructor Details

#initialize(public_key, private_key) ⇒ Box

Returns a new instance of Box.

Parameters:

  • public_key (PublicKey, String) —

    peer’s 32-byte public key

  • private_key (PrivateKey, String) —

    own 32-byte private key



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# File 'lib/nuckle/box.rb', line 18

def initialize(public_key, private_key)
  pk = extract_bytes(public_key, PUBLICKEYBYTES, "public key")
  sk = extract_bytes(private_key, PRIVATEKEYBYTES, "private key")

  # Compute shared secret via Curve25519 DH
  shared = Internals::Curve25519.scalarmult(sk, pk)

  # Derive symmetric key via HSalsa20 (the "beforenm" step)
  key = Internals::Salsa20.hsalsa20(shared, "\x00" * 16)

  @secret_box = SecretBox.new(key)
end

Instance Method Details

#decrypt(nonce, ciphertext) ⇒ Object Also known as: open

Decrypt ciphertext with 24-byte nonce.



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# File 'lib/nuckle/box.rb', line 42

def decrypt(nonce, ciphertext)
  @secret_box.decrypt(nonce, ciphertext)
end

#encrypt(nonce, plaintext) ⇒ Object Also known as: box

Encrypt plaintext with 24-byte nonce.



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# File 'lib/nuckle/box.rb', line 36

def encrypt(nonce, plaintext)
  @secret_box.encrypt(nonce, plaintext)
end

#nonce_bytes ⇒ Integer

Returns required nonce length in bytes.

Returns:

  • (Integer) —

    required nonce length in bytes



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# File 'lib/nuckle/box.rb', line 33

def nonce_bytes = NONCEBYTES