require "random/secure" module Cox class Error < ::Exception end class VerificationFailed < Error end class DecryptionFailed < Error end end require "./cox/*" module Cox def self.encrypt(data, nonce : Nonce, recipient_public_key : PublicKey, sender_secret_key : SecretKey) data_buffer = data.to_slice data_size = data_buffer.bytesize output_buffer = Bytes.new(data_buffer.bytesize + LibSodium::MAC_SIZE) if LibSodium.crypto_box_easy(output_buffer.to_unsafe, data_buffer, data_size, nonce.pointer, recipient_public_key.pointer, sender_secret_key.pointer) != 0 raise Error.new("crypto_box_easy") end output_buffer end def self.encrypt(data, recipient_public_key : PublicKey, sender_secret_key : SecretKey) nonce = Nonce.new {nonce, encrypt(data, nonce, recipient_public_key, sender_secret_key)} end def self.decrypt(data, nonce : Nonce, sender_public_key : PublicKey, recipient_secret_key : SecretKey) data_buffer = data.to_slice data_size = data_buffer.bytesize output_buffer = Bytes.new(data_buffer.bytesize - LibSodium::MAC_SIZE) if LibSodium.crypto_box_open_easy(output_buffer.to_unsafe, data_buffer.to_unsafe, data_size, nonce.pointer, sender_public_key.pointer, recipient_secret_key.pointer) != 0 raise DecryptionFailed.new("crypto_box_open_easy") end output_buffer end def self.sign_detached(message, secret_key : SignSecretKey) message_buffer = message.to_slice message_buffer_size = message_buffer.bytesize signature_output_buffer = Bytes.new(LibSodium::SIGNATURE_SIZE) if LibSodium.crypto_sign_detached(signature_output_buffer.to_unsafe, 0, message_buffer.to_unsafe, message_buffer_size, secret_key.pointer) != 0 raise Error.new("crypto_sign_detached") end signature_output_buffer end def self.verify_detached(signature, message, public_key : SignPublicKey) signature_buffer = signature.to_slice message_buffer = message.to_slice message_buffer_size = message_buffer.bytesize verified = LibSodium.crypto_sign_verify_detached(signature_buffer.to_unsafe, message_buffer.to_unsafe, message_buffer_size, public_key.pointer) verified.zero? end end if Cox::LibSodium.sodium_init() == -1 STDERR.puts("Failed to init libsodium") exit(1) end