From 3b3774ee693c417b5131f79b0c34cca798b4774a Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Fri, 9 Aug 2024 01:26:21 +0000
Subject: [PATCH] Move `UntrustedString` and `PrintableString` to
 `lightning-types`

`lightning-invoice` currently has a dependency on the entire
`lightning` crate just because it wants to use some of the useful
types from it. This is obviously backwards and leads to some
awkwardness like the BOLT 11 invoice signing API in the `lightning`
crate taking a `[u5]` rather than a `Bolt11Invoice`.

This takes one more step, moving the `UntrustedString` and
`PrintableString` types to `lightning-types`.
---
 lightning-types/src/lib.rs                    |  1 +
 .../util => lightning-types/src}/string.rs    | 20 +------------------
 lightning/src/util/mod.rs                     |  5 ++++-
 lightning/src/util/ser.rs                     | 12 +++++++++++
 4 files changed, 18 insertions(+), 20 deletions(-)
 rename {lightning/src/util => lightning-types/src}/string.rs (77%)

diff --git a/lightning-types/src/lib.rs b/lightning-types/src/lib.rs
index bcfb2b62d..1539401d3 100644
--- a/lightning-types/src/lib.rs
+++ b/lightning-types/src/lib.rs
@@ -26,3 +26,4 @@ extern crate core;
 pub mod features;
 pub mod payment;
 pub mod routing;
+pub mod string;
diff --git a/lightning/src/util/string.rs b/lightning-types/src/string.rs
similarity index 77%
rename from lightning/src/util/string.rs
rename to lightning-types/src/string.rs
index ab12486a0..ae5395a52 100644
--- a/lightning/src/util/string.rs
+++ b/lightning-types/src/string.rs
@@ -9,31 +9,13 @@
 
 //! Utilities for strings.
 
+use alloc::string::String;
 use core::fmt;
-use crate::io::{self, Read};
-use crate::ln::msgs;
-use crate::util::ser::{Writeable, Writer, Readable};
-
-#[allow(unused_imports)]
-use crate::prelude::*;
 
 /// Struct to `Display` fields in a safe way using `PrintableString`
 #[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord, Default)]
 pub struct UntrustedString(pub String);
 
-impl Writeable for UntrustedString {
-	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
-		self.0.write(w)
-	}
-}
-
-impl Readable for UntrustedString {
-	fn read<R: Read>(r: &mut R) -> Result<Self, msgs::DecodeError> {
-		let s: String = Readable::read(r)?;
-		Ok(Self(s))
-	}
-}
-
 impl fmt::Display for UntrustedString {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		PrintableString(&self.0).fmt(f)
diff --git a/lightning/src/util/mod.rs b/lightning/src/util/mod.rs
index a81a36c55..cfcea8379 100644
--- a/lightning/src/util/mod.rs
+++ b/lightning/src/util/mod.rs
@@ -21,7 +21,6 @@ pub mod message_signing;
 pub mod invoice;
 pub mod persist;
 pub mod scid_utils;
-pub mod string;
 pub mod sweep;
 pub mod wakers;
 #[cfg(fuzzing)]
@@ -54,3 +53,7 @@ pub mod test_utils;
 #[cfg(any(test, feature = "_test_utils"))]
 pub mod test_channel_signer;
 
+pub mod string {
+	//! Utilities to wrap untrusted strings and handle them (more) safely
+	pub use lightning_types::string::{PrintableString, UntrustedString};
+}
diff --git a/lightning/src/util/ser.rs b/lightning/src/util/ser.rs
index 3d3d97252..29c52f6a0 100644
--- a/lightning/src/util/ser.rs
+++ b/lightning/src/util/ser.rs
@@ -627,6 +627,18 @@ impl<'a> From<&'a String> for WithoutLength<&'a String> {
 	fn from(s: &'a String) -> Self { Self(s) }
 }
 
+impl Writeable for UntrustedString {
+	fn write<W: Writer>(&self, w: &mut W) -> Result<(), io::Error> {
+		self.0.write(w)
+	}
+}
+
+impl Readable for UntrustedString {
+	fn read<R: Read>(r: &mut R) -> Result<Self, DecodeError> {
+		let s: String = Readable::read(r)?;
+		Ok(Self(s))
+	}
+}
 
 impl Writeable for WithoutLength<&UntrustedString> {
 	#[inline]
-- 
2.39.5