require "./lib_sodium" require "./wipe" require "./crypto_box/secret_key" require "./nonce" module Sodium # Use Sodium::CryptoBox::SecretKey#box class CryptoBox include Wipe MAC_SIZE = LibSodium.crypto_box_macbytes.to_i # :nodoc: NM_SIZE = LibSodium.crypto_box_beforenmbytes.to_i raise "NM_SIZE=#{NM_SIZE}, assumed it was 32" if NM_SIZE != 32 @[Wipe::Var] @key = StaticArray(UInt8, 32).new 0 # :nodoc: # Used by SecretKey#box def initialize(@secret_key : SecretKey, @public_key : PublicKey) # Precalculate key for later use. # Large speed gains with small data sizes and many messages. # Small speed gains with large data sizes or few messages. if LibSodium.crypto_box_beforenm(@key, @public_key.to_slice, @secret_key.to_slice) != 0 raise Error.new("crypto_box_beforenm") end end # Encrypts data and returns {ciphertext, nonce} def encrypt(src) encrypt src.to_slice end # Encrypts data and returns {ciphertext, nonce} # # Optionally supply a destination buffer. def encrypt(src : Bytes, dst = Bytes.new(src.bytesize + MAC_SIZE), nonce = Nonce.new) : {Bytes, Nonce} if LibSodium.crypto_box_easy_afternm(dst, src, src.bytesize, nonce.to_slice, @key.to_slice) != 0 raise Error.new("crypto_box_easy") end {dst, nonce} end # Returns decrypted message. # def decrypt(src) decrypt src.to_slice end # Returns decrypted message. # # Optionally supply a destination buffer. def decrypt(src : Bytes, dst = Bytes.new(src.bytesize - MAC_SIZE), nonce = Nonce.random) : Bytes if LibSodium.crypto_box_open_easy_afternm(dst, src, src.bytesize, nonce.to_slice, @key) != 0 raise Error::DecryptionFailed.new("crypto_box_open_easy") end dst end # TODO detached end end