diff --git a/src/sodium/cipher/chalsa.cr b/src/sodium/cipher/chalsa.cr index 854feaa..ab74a0e 100644 --- a/src/sodium/cipher/chalsa.cr +++ b/src/sodium/cipher/chalsa.cr @@ -6,6 +6,8 @@ module Sodium::Cipher # # What? They're both dance? abstract class Chalsa + include Random + getter key : Crypto::Secret getter! nonce : Bytes? @@ -42,7 +44,7 @@ module Sodium::Cipher end def random_nonce - self.nonce = Random::Secure.random_bytes nonce_size + self.nonce = ::Random::Secure.random_bytes nonce_size end # Xor's src with the cipher output and returns a new Slice @@ -60,17 +62,14 @@ module Sodium::Cipher # Use as a CSPRNG. def random_bytes(bytes : Bytes) : Bytes - # TODO: Switch to memset - Sodium.memzero bytes update bytes, bytes bytes end - # Use as a CSPRNG. - def random_bytes(size : Int) : Bytes - bytes = Bytes.new size - update bytes, bytes - bytes + def next_u : UInt8 + buf = uninitialized UInt8[1] + random_bytes buf.to_slice + buf.unsafe_as(UInt8) end # Always returns false. Sadness... @@ -90,11 +89,22 @@ module Sodium::Cipher {% for key, val in {"XSalsa20" => "xsalsa20", "Salsa20" => "salsa20", "XChaCha20" => "xchacha20", "ChaCha20Ietf" => "chacha20_ietf", "ChaCha20" => "chacha20"} %} # These classes can be used to generate pseudo-random data from a key, # or as building blocks for implementing custom constructions, but they - # are not alternatives to secretbox. + # are not alternatives to `SecretBox`. # # See [https://libsodium.gitbook.io/doc/advanced/stream_ciphers](https://libsodium.gitbook.io/doc/advanced/stream_ciphers) for further information. # - # This class mimicks the OpenSSL::Cipher interface with minor differences. + # This class mimicks the `OpenSSL::Cipher` interface with minor differences. + # + # Also provides a `::Random` interface. + # * Lacks forward secrecy. + # * ~3x faster than `::Random::Secure` + # + # Use with caution. When in doubt use `::Random::Secure` + # + # Possibly safe uses: + # * Test data + # * Overwriting storage with random data + # * Single player video games (maybe) # # See `spec/sodium/cipher/chalsa_spec.cr` for examples on how to use this class. # @@ -104,7 +114,7 @@ module Sodium::Cipher NONCE_SIZE = LibSodium.crypto_stream_{{ val.id }}_noncebytes.to_i32 def self.random - new key: Sodium::SecureBuffer.random(KEY_SIZE), nonce: Random::Secure.random_bytes(NONCE_SIZE) + new key: Sodium::SecureBuffer.random(KEY_SIZE), nonce: ::Random::Secure.random_bytes(NONCE_SIZE) end # Xor's src with the cipher output and places in dst.