View Source SensitiveData (Sensitive Data v0.1.0)

This library aims to make data leak prevention straightforward and convenient, by making it easy to follow most of the Erlang Ecosystem Foundation's recommendations regarding protecting sensitive data.

For a quick overview, take a look at the Getting Started and Cheatsheet pages.

While wrapping sensitive data within a SensitiveData.Wrapper instance will conform to many recommendations in the linked article (such as wrapping sensitive data in a closure, pruning stack traces, and deriving the Inspect protocol), it doesn't cover others which may be relevant to your situation (such as using the :private option for ETS tables containing sensitive data, flagging the current process as sensitive using :erlang.process_flag(:sensitive, true) in processes holding sensitive data, and so on).

Beware
This library is intended to prevent accidental leakage of sensitive data, it WILL NOT keep data safe from a malicious actor that has access to your system. For example, the wrapped sensitive data could be read via BEAM introspection functionality, such as :erlang.fun_info(..., :env)

Summary

Types

exec_opts()

Functions

exec(fun, opts \\ [])

Executes the provided function, ensuring no data leaks in case of error.

gets_sensitive(prompt, opts \\ [])

Reads a line from stdin, without echoing the input back to the console.

Types

exec_opts()

@type exec_opts() :: [
  into: SensitiveData.Wrapper.spec(),
  exception_redactor: SensitiveData.Redaction.exception_redactor(),
  stacktrace_redactor: SensitiveData.Redaction.stacktrace_redactor()
]

Functions

exec(fun, opts \\ [])

@spec exec((-> result), exec_opts()) :: result
when result: term() | SensitiveData.Wrapper.t() | no_return()

Executes the provided function, ensuring no data leaks in case of error.

Options

:into - a SensitiveData.Wrapper.spec/0 value into which the fun execution result should be wrapped.
:exception_redactor - the SensitiveData.Redaction.exception_redactor/0 to use when redacting an Exception.t/0. Defaults to SensitiveData.Redactors.Exception.drop/1, which is also the fallback if the custom redactor fails. See Custom Failure Redaction.
:stacktrace_redactor - the SensitiveData.Redaction.stacktrace_redactor/0 to use when redacting a stack trace. Defaults to SensitiveData.Redactors.Stacktrace.strip/1, which is also the fallback if the custom redactor fails. See Custom Failure Redaction.

Examples

iex> Map.get("SOME_PASSWORD", :foobar)
** (BadMapError) expected a map, got: "SOME_PASSWORD"

iex> SensitiveData.exec(fn ->
...>   Map.get("SOME_PASSWORD", :foobar)
...> end)
** (SensitiveData.RedactedException) an exception of type `BadMapError` was raised in a sensitive context

Passing the execution result to a SecretData module implementing the SensitiveData.Wrapper behaviour:

SensitiveData.exec(fn ->
  System.fetch_env!("DATABASE_PASSWORD")
end, into: SecretData)
#SecretData<...>

gets_sensitive(prompt, opts \\ [])

@spec gets_sensitive(prompt, [{:into, SensitiveData.Wrapper.spec()}]) ::
  user_input | SensitiveData.Wrapper.t()
when prompt: String.t(), user_input: String.t()

Reads a line from stdin, without echoing the input back to the console.

Options

:into - a SensitiveData.Wrapper.spec/0 value into which the input should be wrapped. By default, the input is not wrapped and is returned as-is, similarly to IO.gets/2.

Examples

To display a prompt and await user input:

SensitiveData.gets_sensitive("Enter your database password: ")

To do the same but wrap the result within a SecretData module implementing the SensitiveData.Wrapper behaviour:

SensitiveData.gets_sensitive("Enter your database password: ",
  into: SecretData)