From 8e978703528187520005b0f5062b8f24a8613190 Mon Sep 17 00:00:00 2001
From: kitsunecafe <rowan@kitsu.cafe>
Date: Sun, 6 Oct 2024 03:00:17 -0500
Subject: [PATCH] serde feature and support

---
 Cargo.lock           | 56 +++++++++++++++++++++++++++++++++
 Cargo.toml           |  2 ++
 src/lib.rs           |  5 ++-
 src/serialization.rs | 73 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 135 insertions(+), 1 deletion(-)
 create mode 100644 src/serialization.rs

diff --git a/Cargo.lock b/Cargo.lock
index ff734a7..3c4fd98 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -68,6 +68,44 @@ version = "0.2.159"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5e719e8df665df0d1c8fbfd238015744736151d4445ec0836b8e628aae103b77"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.37"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5b9d34b8991d19d98081b46eacdd8eb58c6f2b201139f7c5f643cc155a633af"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "serde"
+version = "1.0.210"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8e3592472072e6e22e0a54d5904d9febf8508f65fb8552499a1abc7d1078c3a"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.210"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "243902eda00fad750862fc144cea25caca5e20d615af0a81bee94ca738f1df1f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "sha2"
 version = "0.10.8"
@@ -84,15 +122,33 @@ name = "subresource_integrity"
 version = "0.1.0"
 dependencies = [
  "base64",
+ "serde",
  "sha2",
 ]
 
+[[package]]
+name = "syn"
+version = "2.0.79"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89132cd0bf050864e1d38dc3bbc07a0eb8e7530af26344d3d2bbbef83499f590"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "typenum"
 version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "unicode-ident"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e91b56cd4cadaeb79bbf1a5645f6b4f8dc5bde8834ad5894a8db35fda9efa1fe"
+
 [[package]]
 name = "version_check"
 version = "0.9.5"
diff --git a/Cargo.toml b/Cargo.toml
index 100ee93..4d799f4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,9 @@ edition = "2021"
 
 [features]
 default = []
+serde = ["dep:serde"]
 
 [dependencies]
 base64 = "0.22.1"
+serde = { version = "1.0.210", features = ["derive"], optional = true }
 sha2 = "0.10.8"
diff --git a/src/lib.rs b/src/lib.rs
index 4861751..08472ab 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,6 @@
+#[cfg(feature = "serde")]
+pub mod serialization;
+
 use core::fmt;
 
 use base64::{prelude::BASE64_STANDARD, Engine};
@@ -11,6 +14,7 @@ pub enum Error {
 }
 
 #[derive(Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum Algorithm {
     SHA256,
     SHA384,
@@ -102,7 +106,6 @@ impl TryFrom<&str> for Integrity {
 
     fn try_from(value: &str) -> Result<Self, Self::Error> {
         let (algo, hash) = Self::split(value)?;
-        println!("{algo} {hash}");
         Self::from_base64(Algorithm::try_from(algo)?, hash)
     }
 }
diff --git a/src/serialization.rs b/src/serialization.rs
new file mode 100644
index 0000000..f490d65
--- /dev/null
+++ b/src/serialization.rs
@@ -0,0 +1,73 @@
+use serde::Serialize;
+
+use crate::Integrity;
+
+impl Serialize for Integrity {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(self.to_string().as_str())
+    }
+}
+
+impl<'de> serde::Deserialize<'de> for Integrity {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        deserializer.deserialize_string(IntegrityVisitor)
+    }
+}
+
+struct IntegrityVisitor;
+impl<'de> serde::de::Visitor<'de> for IntegrityVisitor {
+    type Value = Integrity;
+
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str("a string with the format of <hash-algo>-<base64-hash>")
+    }
+
+    fn visit_str<E>(self, v: &str) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        Integrity::try_from(v).map_err(|_| E::custom("invalid sri"))
+    }
+
+    fn visit_borrowed_str<E>(self, v: &'de str) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        Integrity::try_from(v).map_err(|_| E::custom("invalid sri"))
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+    where
+        E: serde::de::Error,
+    {
+        Integrity::try_from(v).map_err(|_| E::custom("invalid sri"))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use serde::{
+        de::{
+            value::{Error as ValueError, StrDeserializer},
+            IntoDeserializer,
+        },
+        Deserialize,
+    };
+
+    use crate::Integrity;
+
+    #[test]
+    fn serde_deserialization() {
+        let de: StrDeserializer<ValueError> =
+            "sha384-H8BRh8j48O9oYatfu5AZzq6A9RINhZO5H16dQZngK7T62em8MUt1FLm52t+eX6xO"
+                .into_deserializer();
+        let result = Integrity::deserialize(de).unwrap();
+        assert!(result.verify("alert(\'Hello, world.\');"));
+    }
+}