Add AES stream codecs #19
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lib/kryptonite/aes.ex
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| ## Examples | ||
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| iex> {key, iv} = {generate_key!(), Random.bytes!(16)} | ||
| iex> cypher = 'This is a secret' |> stream_encrypt(key, iv) |> Enum.to_list() |
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Readability:
iex> cypher = "This is a secret"
...> |> stream_encrypt(key, iv)
...> |> Enum.to_list()
lib/kryptonite/aes.ex
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| iex> {key, iv} = {generate_key!(), Random.bytes!(16)} | ||
| iex> msg = "This is a secret..." | ||
| iex> cypher = msg |> String.to_charlist() |> stream_encrypt(key, iv) |> Enum.to_list() | ||
| iex> msg == cypher |> stream_decrypt(key, iv) |> Enum.to_list() |> :erlang.iolist_to_binary |
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Cool! Readability:
iex> msg == cypher
...> |> stream_decrypt(key, iv)
...> |> Enum.to_list()
...> |> :erlang.iolist_to_binary
| ## Examples | ||
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| iex> {key, iv} = {generate_key!(), Random.bytes!(16)} | ||
| iex> File.write!("/tmp/plain.txt", "This is a secret") |
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Race condition here when running parallel builds. I'd probably add a timestamp based identifier to the filename. WDYT?
| iex> {:ok, tag} = | ||
| ...> "/tmp/plain.txt" | ||
| ...> |> File.stream!() | ||
| ...> |> stream_encrypt(File.stream!("/tmp/secret.aes"), key, iv, "Auth...") |
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Race condition - maybe reuse the same timestamp / random identifier here?
| @doc """ | ||
| Check integrity then decrypts a stream encrypted with `stream_encrypt/5` | ||
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| Raise `Kryptonite.AES.StreamIntegrityError` in case of integrity checking error. |
| |> Stream.concat(in_stream) | ||
| |> stream_tag(ad) | ||
| |> case do | ||
| ^tag -> |
| @@ -244,4 +346,9 @@ defmodule Kryptonite.AES do | |||
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| @spec cut_key(binary) :: binary | |||
| defp cut_key(<<key::binary-size(@key_byte_size), _::binary>>), do: key | |||
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| defp do_stream_encrypt(elem, acc) do | |||
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Maybe we could have this a def instead of defp so later we could unit-test it in isolation and have a @spec that properly guards weird changes from happening?
| @@ -244,4 +346,9 @@ defmodule Kryptonite.AES do | |||
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| @spec cut_key(binary) :: binary | |||
| defp cut_key(<<key::binary-size(@key_byte_size), _::binary>>), do: key | |||
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| defp do_stream_encrypt(elem, acc) do | |||
| {acc, cypher} = :crypto.stream_encrypt(acc, elem |> List.wrap()) | |||
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I wish we could pipe stuff on 2nd argument... Wouldn't an infix library be awesome? Something that would allow:
{acc, cypher} = elem
|> List.wrap()
2> :crypto.stream_encrypt(acc)
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@jeanparpaillon I'm closing this, because I needed to be able to change it and I didn't have access to your repo. Instead I've opened a PR on a local branch that you also have access to. See #20 |
When encoding (large files), working with binaries can rapidly kill the VM.
This patch adds 2 functions for encoding and decoding streams with AES (CTR mode)
For instance: