#![cfg_attr(docsrs, feature(doc_auto_cfg, doc_cfg))]

#![doc = include_str!("../README.md")]

// @@ begin lint list maintained by maint/add_warning @@

#![allow(renamed_and_removed_lints)] // @@REMOVE_WHEN(ci_arti_stable)

#![allow(unknown_lints)] // @@REMOVE_WHEN(ci_arti_nightly)

#![warn(missing_docs)]

#![warn(noop_method_call)]

#![warn(unreachable_pub)]

#![warn(clippy::all)]

#![deny(clippy::await_holding_lock)]

#![deny(clippy::cargo_common_metadata)]

#![deny(clippy::cast_lossless)]

#![deny(clippy::checked_conversions)]

#![warn(clippy::cognitive_complexity)]

#![deny(clippy::debug_assert_with_mut_call)]

#![deny(clippy::exhaustive_enums)]

#![deny(clippy::exhaustive_structs)]

#![deny(clippy::expl_impl_clone_on_copy)]

#![deny(clippy::fallible_impl_from)]

#![deny(clippy::implicit_clone)]

#![deny(clippy::large_stack_arrays)]

#![warn(clippy::manual_ok_or)]

#![deny(clippy::missing_docs_in_private_items)]

#![warn(clippy::needless_borrow)]

#![warn(clippy::needless_pass_by_value)]

#![warn(clippy::option_option)]

#![deny(clippy::print_stderr)]

#![deny(clippy::print_stdout)]

#![warn(clippy::rc_buffer)]

#![deny(clippy::ref_option_ref)]

#![warn(clippy::semicolon_if_nothing_returned)]

#![warn(clippy::trait_duplication_in_bounds)]

#![deny(clippy::unchecked_duration_subtraction)]

#![deny(clippy::unnecessary_wraps)]

#![warn(clippy::unseparated_literal_suffix)]

#![deny(clippy::unwrap_used)]

#![deny(clippy::mod_module_files)]

#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness

#![allow(clippy::uninlined_format_args)]

#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945

#![allow(clippy::result_large_err)] // temporary workaround for arti#587

#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best

#![allow(clippy::needless_lifetimes)] // See arti#1765

#![allow(mismatched_lifetime_syntaxes)] // temporary workaround for arti#2060

//! <!-- @@ end lint list maintained by maint/add_warning @@ -->

// TODO: Try making it not Deref and having expose+expose_mut instead; how bad is it?

use educe::Educe;

#[cfg(feature = "serde")]

use serde::{Deserialize, Serialize};

mod err;

mod flags;

mod impls;

pub use err::Error;

pub use flags::{Guard, disable_safe_logging, enforce_safe_logging, with_safe_logging_suppressed};

use std::ops::Deref;

/// A `Result` returned by the flag-manipulation functions in `safelog`.

pub type Result<T> = std::result::Result<T, Error>;

// Re-exported for macros.

#[doc(hidden)]

pub use flags::unsafe_logging_enabled;

/// A wrapper type for a sensitive value.

///

/// By default, a `Sensitive<T>` behaves the same as a regular `T`, except that

/// attempts to turn it into a string (via `Display`, `Debug`, etc) all produce

/// the string `[scrubbed]`.

///

/// This behavior can be overridden locally by using

/// [`with_safe_logging_suppressed`] and globally with [`disable_safe_logging`].

#[educe(

    Default(bound),

    Deref,

    DerefMut,

    Eq(bound),

    Hash(bound),

    Ord(bound),

    PartialEq(bound),

    PartialOrd(bound)

)]

#[cfg_attr(feature = "serde", serde(transparent))]

pub struct Sensitive<T>(T);

impl<T> Sensitive<T> {

    /// Create a new `Sensitive<T>`, wrapping a provided `value`.

    /// Extract the inner value from this `Sensitive<T>`.

    /// Extract the inner value from this `Sensitive<T>`.

    #[deprecated = "Use the new into_inner method instead"]

    /// Converts `&Sensitive<T>` to `Sensitive<&T>`

    /// Return a reference to the inner value

    //

    // This isn't `AsRef` or `as_ref` because we don't want to offer "de-sensitivisation"

    // via what is usually a semantically-neutral interface.

}

/// Wrap a value as `Sensitive`.

///

/// This function is an alias for [`Sensitive::new`].

impl<T> From<T> for Sensitive<T> {

}

/// Helper: Declare one or more Display-like implementations for a

/// Sensitive-like type.  These implementations will delegate to their std::fmt

/// types if safe logging is disabled, and write `[scrubbed]` otherwise.

macro_rules! impl_display_traits {

    { $($trait:ident),* } => {

    $(

        impl<T: std::fmt::$trait> std::fmt::$trait for Sensitive<T> {

                } else {

                }

        }

        impl<T: std::fmt::$trait> std::fmt::$trait for BoxSensitive<T> {

            #[inline]

        }

   )*

   }

}

/// A wrapper suitable for logging and including in errors

///

/// This is a newtype around `Box<Sensitive<T>>`.

///

/// This is useful particularly in errors,

/// where the box can help reduce the size of error variants

/// (for example ones containing large values like an `OwnedChanTarget`).

///

/// `BoxSensitive<T>` dereferences to [`Sensitive<T>`].

//

// Making it be a newtype rather than a type alias allows us to implement

// `into_inner` and `From<T>` and so on.

#[derive(Clone, Hash, Eq, PartialEq, Ord, PartialOrd)]

pub struct BoxSensitive<T>(Box<Sensitive<T>>);

impl<T> From<T> for BoxSensitive<T> {

}

impl<T> BoxSensitive<T> {

    /// Return the innermost `T`

}

impl<T> Deref for BoxSensitive<T> {

    type Target = Sensitive<T>;

}

impl_display_traits! {

    Display, Debug, Binary, Octal, LowerHex, UpperHex, LowerExp, UpperExp, Pointer

}

/// A `redactable` object is one where we know a way to display _part_ of it

/// when we are running with safe logging enabled.

///

/// For example, instead of referring to a user as `So-and-So` or `[scrubbed]`,

/// this trait would allow referring to the user as `S[...]`.

///

/// # Privacy notes

///

/// Displaying some information about an object is always less safe than

/// displaying no information about it!

///

/// For example, in an environment with only a small number of users, the first

/// letter of a user's name might be plenty of information to identify them

/// uniquely.

///

/// Even if a piece of redacted information is safe on its own, several pieces

/// of redacted information, when taken together, can be enough for an adversary

/// to infer more than you want.  For example, if you log somebody's first

/// initial, month of birth, and last-two-digits of ID number, you have just

/// discarded 99.9% of potential individuals from the attacker's consideration.

pub trait Redactable: std::fmt::Display + std::fmt::Debug {

    /// As `Display::fmt`, but produce a redacted representation.

    fn display_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;

    /// As `Debug::fmt`, but produce a redacted representation.

    /// Return a smart pointer that will display or debug this object as its

    /// redacted form.

    /// Return a smart pointer that redacts this object if `redact` is true.

        } else {

        }

}

impl<'a, T: Redactable + ?Sized> Redactable for &'a T {

}

/// A wrapper around a `Redactable` that displays it in redacted format.

#[educe(

    Default(bound),

    Deref,

    DerefMut,

    Eq(bound),

    Hash(bound),

    Ord(bound),

    PartialEq(bound),

    PartialOrd(bound)

)]

#[derive(derive_more::From)]

#[cfg_attr(feature = "serde", serde(transparent))]

pub struct Redacted<T: Redactable>(T);

impl<T: Redactable> Redacted<T> {

    /// Create a new `Redacted`.

    /// Consume this wrapper and return its inner value.

    /// Converts `&Redacted<T>` to `Redacted<&T>`

    /// Return a reference to the inner value

    //

    // This isn't `AsRef` or `as_ref` because we don't want to offer "de-redaction"

    // via what is usually a semantically-neutral interface.

}

impl<T: Redactable> std::fmt::Display for Redacted<T> {

        } else {

        }

}

impl<T: Redactable> std::fmt::Debug for Redacted<T> {

        } else {

        }

}

/// An object that may or may not be redacted.

///

/// Used to implement conditional redaction

#[derive(Clone, derive_more::Display)]

pub struct MaybeRedacted<T: Redactable>(either::Either<T, Redacted<T>>);

impl<T: Redactable> std::fmt::Debug for MaybeRedacted<T> {

        use std::fmt::Debug;

        }

}

/// A type that can be displayed in a redacted or un-redacted form,

/// but which forces the caller to choose.

///

/// See [`Redactable`] for more discussion on redaction.

///

/// Unlike [`Redactable`], this type is "inherently sensitive":

/// Types implementing `DisplayRedacted` should not typically implement

/// [`Display`](std::fmt::Display).

///

/// For external types that implement `Display`,

/// or for types which are usually _not_ sensitive,

/// `Redacted` is likely a better choice.

pub trait DisplayRedacted {

    /// As [`Display::fmt`](std::fmt::Display::fmt), but write this object

    /// in its redacted form.

    fn fmt_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;

    /// As [`Display::fmt`](std::fmt::Display::fmt), but write this object

    /// in its un-redacted form.

    fn fmt_unredacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;

    // TODO: At some point in the future, when default values are supported for GATs,

    // it might be good to turn these RPIT functions into associated types.

    /// Return a pointer wrapping this object that can be Displayed in redacted form

    /// if safe-logging is enabled.

    ///

    /// (If safe-logging is not enabled, it will de displayed in its unredacted form.)

    /// Return a pointer wrapping this object that can be Displayed in unredacted form.

}

impl<'a, T> DisplayRedacted for &'a T

where

    T: DisplayRedacted + ?Sized,

{

}

/// A wrapper around a [`DisplayRedacted`] that implements [`Display`](std::fmt::Display)

/// by displaying the object in its redacted form

/// if safe-logging is enabled.

///

/// (If safe-logging is not enabled, it will de displayed in its unredacted form.)

#[allow(clippy::exhaustive_structs)]

#[derive(derive_more::AsRef)]

pub struct DispRedacted<T: ?Sized>(pub T);

/// A wrapper around a [`DisplayRedacted`] that implements [`Display`](std::fmt::Display)

/// by displaying the object in its un-redacted form.

#[allow(clippy::exhaustive_structs)]

#[derive(derive_more::AsRef)]

pub struct DispUnredacted<T: ?Sized>(pub T);

impl<T> std::fmt::Display for DispRedacted<T>

where

    T: DisplayRedacted + ?Sized,

{

        } else {

        }

}

impl<T> std::fmt::Display for DispUnredacted<T>

where

    T: DisplayRedacted + ?Sized,

{

}

/// A type that can be debugged in a redacted or un-redacted form,

/// but which forces the caller to choose.

///

/// See [`Redactable`] for more discussion on redaction.

///

/// Unlike [`Redactable`], this type is "inherently sensitive":

/// [`Debug`](std::fmt::Debug) will display it in redacted or un-redacted format

/// depending on whether safe logging is enabled.

///

/// For external types that implement `Debug`,

/// or for types which are usually _not_ sensitive,

/// `Redacted` is likely a better choice.

pub trait DebugRedacted {

    /// As [`Debug::fmt`](std::fmt::Debug::fmt), but write this object

    /// in its redacted form.

    fn fmt_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;

    /// As [`Debug::fmt`](std::fmt::Debug::fmt), but write this object

    /// in its unredacted form.

    fn fmt_unredacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result;

}

/// Implement [`std::fmt::Debug`] for a type that implements [`DebugRedacted`].

///

/// The implementation will use fmt_redacted() when safe-logging is enabled,

/// and fmt_unredacted() otherwise.

///

/// (NOTE we can't just write 'impl<T:DebugRedacted> Debug for T`;

/// Rust doesn't like it.)

#[macro_export]

macro_rules! derive_redacted_debug {

    {$t:ty} => {

    impl std::fmt::Debug for $t {

            } else {

            }

    }

}}

#[cfg(test)]

mod test {

    // @@ begin test lint list maintained by maint/add_warning @@

    #![allow(clippy::bool_assert_comparison)]

    #![allow(clippy::clone_on_copy)]

    #![allow(clippy::dbg_macro)]

    #![allow(clippy::mixed_attributes_style)]

    #![allow(clippy::print_stderr)]

    #![allow(clippy::print_stdout)]

    #![allow(clippy::single_char_pattern)]

    #![allow(clippy::unwrap_used)]

    #![allow(clippy::unchecked_duration_subtraction)]

    #![allow(clippy::useless_vec)]

    #![allow(clippy::needless_pass_by_value)]

    //! <!-- @@ end test lint list maintained by maint/add_warning @@ -->

    use super::*;

    use serial_test::serial;

    use static_assertions::{assert_impl_all, assert_not_impl_any};

    #[test]

    fn clone_bound() {

        // Here we'll make sure that educe bounds work about the way we expect.

        #[derive(Clone)]

        struct A;

        struct B;

        let _x = Sensitive(A).clone();

        let _y = Sensitive(B);

        assert_impl_all!(Sensitive<A> : Clone);

        assert_not_impl_any!(Sensitive<B> : Clone);

    }

    #[test]

    #[serial]

    fn debug_vec() {

        type SVec = Sensitive<Vec<u32>>;

        let mut sv = SVec::default();

        assert!(sv.is_empty());

        sv.push(104);

        sv.push(49);

        assert_eq!(sv.len(), 2);

        assert!(!flags::unsafe_logging_enabled());

        assert_eq!(format!("{:?}", &sv), "[scrubbed]");

        assert_eq!(format!("{:?}", sv.as_ref()), "[scrubbed]");

        assert_eq!(format!("{:?}", sv.as_inner()), "[104, 49]");

        let normal = with_safe_logging_suppressed(|| format!("{:?}", &sv));

        assert_eq!(normal, "[104, 49]");

        let _g = disable_safe_logging().unwrap();

        assert_eq!(format!("{:?}", &sv), "[104, 49]");

        assert_eq!(sv, SVec::from(vec![104, 49]));

        assert_eq!(sv.clone().into_inner(), vec![104, 49]);

        assert_eq!(*sv, vec![104, 49]);

    }

    #[test]

    #[serial]

    #[allow(deprecated)]

    fn deprecated() {

        type SVec = Sensitive<Vec<u32>>;

        let sv = Sensitive(vec![104, 49]);

        assert_eq!(SVec::unwrap(sv), vec![104, 49]);

    }

    #[test]

    #[serial]

    fn display_various() {

        let val = Sensitive::<u32>::new(0x0ed19a);

        let closure1 = || {

            format!(

                "{:?}, {}, {:o}, {:x}, {:X}, {:b}",

                &val, &val, &val, &val, &val, &val,

            )

        };

        let s1 = closure1();

        let s2 = with_safe_logging_suppressed(closure1);

        assert_eq!(

            s1,

            "[scrubbed], [scrubbed], [scrubbed], [scrubbed], [scrubbed], [scrubbed]"

        );

        assert_eq!(

            s2,

            "971162, 971162, 3550632, ed19a, ED19A, 11101101000110011010"

        );

        let n = 1.0E32;

        let val = Sensitive::<f64>::new(n);

        let expect = format!("{:?}, {}, {:e}, {:E}", n, n, n, n);

        let closure2 = || format!("{:?}, {}, {:e}, {:E}", &val, &val, &val, &val);

        let s1 = closure2();

        let s2 = with_safe_logging_suppressed(closure2);

        assert_eq!(s1, "[scrubbed], [scrubbed], [scrubbed], [scrubbed]");

        assert_eq!(s2, expect);

        let ptr: *const u8 = std::ptr::null();

        let val = Sensitive::new(ptr);

        let expect = format!("{:?}, {:p}", ptr, ptr);

        let closure3 = || format!("{:?}, {:p}", val, val);

        let s1 = closure3();

        let s2 = with_safe_logging_suppressed(closure3);

        assert_eq!(s1, "[scrubbed], [scrubbed]");

        assert_eq!(s2, expect);

    }

    #[test]

    #[serial]

    fn box_sensitive() {

        let b: BoxSensitive<_> = "hello world".into();

        assert_eq!(b.clone().into_inner(), "hello world");

        let closure = || format!("{} {:?}", b, b);

        assert_eq!(closure(), "[scrubbed] [scrubbed]");

        assert_eq!(

            with_safe_logging_suppressed(closure),

            r#"hello world "hello world""#

        );

        assert_eq!(b.len(), 11);

    }

    #[test]

    #[serial]

    fn test_redacted() {

        let localhost = std::net::Ipv4Addr::LOCALHOST;

        let closure = || format!("{} {:?}", localhost.redacted(), localhost.redacted());

        assert_eq!(closure(), "127.x.x.x 127.x.x.x");

        assert_eq!(with_safe_logging_suppressed(closure), "127.0.0.1 127.0.0.1");

        let closure = |b| {

            format!(

                "{} {:?}",

                localhost.maybe_redacted(b),

                localhost.maybe_redacted(b)

            )

        };

        assert_eq!(closure(true), "127.x.x.x 127.x.x.x");

        assert_eq!(closure(false), "127.0.0.1 127.0.0.1");

        assert_eq!(Redacted::new(localhost).unwrap(), localhost);

    }

    struct RedactionCheck(u32);

    impl DisplayRedacted for RedactionCheck {

        fn fmt_unredacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

            write!(f, "{}", self.0)

        }

        fn fmt_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

            let v = self.0.to_string();

            write!(f, "{}xxx", v.chars().next().unwrap())

        }

    }

    impl DebugRedacted for RedactionCheck {

        fn fmt_redacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

            write!(f, "Num({})", self.display_redacted())

        }

        fn fmt_unredacted(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {

            write!(f, "Num({})", self.display_unredacted())

        }

    }

    derive_redacted_debug!(RedactionCheck);

    #[test]

    #[serial]

    fn display_redacted() {

        let n = RedactionCheck(999);

        assert_eq!(&n.display_unredacted().to_string(), "999");

        assert_eq!(&n.display_redacted().to_string(), "9xxx");

        with_safe_logging_suppressed(|| assert_eq!(&n.display_redacted().to_string(), "999"));

        assert_eq!(DispRedacted(&n).to_string(), "9xxx");

        assert_eq!(DispUnredacted(&n).to_string(), "999");

        assert_eq!(&format!("{n:?}"), "Num(9xxx)");

        with_safe_logging_suppressed(|| assert_eq!(&format!("{n:?}"), "Num(999)"));

    }

}