From 3cbdf91cf1df4049248f458db24afa4348a43bdf Mon Sep 17 00:00:00 2001
From: kitsunecafe <rowan@kitsu.cafe>
Date: Sun, 6 Oct 2024 03:41:27 -0500
Subject: [PATCH] md5

---
 Cargo.lock | 11 +++++++++++
 Cargo.toml |  2 ++
 src/lib.rs | 22 ++++++++++++++++++++++
 3 files changed, 35 insertions(+)

diff --git a/Cargo.lock b/Cargo.lock
index 3c4fd98..c545fdb 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -68,6 +68,16 @@ version = "0.2.159"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
 
+[[package]]
+name = "md-5"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d89e7ee0cfbedfc4da3340218492196241d89eefb6dab27de5df917a6d2e78cf"
+dependencies = [
+ "cfg-if",
+ "digest",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.86"
@@ -122,6 +132,7 @@ name = "subresource_integrity"
 version = "0.1.0"
 dependencies = [
  "base64",
+ "md-5",
  "serde",
  "sha2",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 4d799f4..a5ec3fa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,8 +6,10 @@ edition = "2021"
 [features]
 default = []
 serde = ["dep:serde"]
+md5 = ["dep:md-5"]
 
 [dependencies]
 base64 = "0.22.1"
+md-5 = { version = "0.10.6", optional = true }
 serde = { version = "1.0.210", features = ["derive"], optional = true }
 sha2 = "0.10.8"
diff --git a/src/lib.rs b/src/lib.rs
index 08472ab..e772b7b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,6 +16,8 @@ pub enum Error {
 #[derive(Debug, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub enum Algorithm {
+    #[cfg(feature = "md5")]
+    MD5,
     SHA256,
     SHA384,
     SHA512,
@@ -24,6 +26,8 @@ pub enum Algorithm {
 impl Algorithm {
     pub fn digest(&self, data: impl AsRef<[u8]>) -> Vec<u8> {
         match self {
+            #[cfg(feature = "md5")]
+            Self::MD5 => md5::Md5::digest(data).to_vec(),
             Self::SHA256 => sha2::Sha256::digest(data).to_vec(),
             Self::SHA384 => sha2::Sha384::digest(data).to_vec(),
             Self::SHA512 => sha2::Sha512::digest(data).to_vec(),
@@ -34,6 +38,8 @@ impl Algorithm {
 impl fmt::Display for Algorithm {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let value = match self {
+            #[cfg(feature = "md5")]
+            Self::MD5 => "md5",
             Self::SHA256 => "sha256",
             Self::SHA384 => "sha384",
             Self::SHA512 => "sha512",
@@ -48,6 +54,8 @@ impl TryFrom<&str> for Algorithm {
 
     fn try_from(value: &str) -> Result<Self, Self::Error> {
         match value {
+            #[cfg(feature = "md5")]
+            "md5" => Ok(Self::MD5),
             "sha256" => Ok(Self::SHA256),
             "sha384" => Ok(Self::SHA384),
             "sha512" => Ok(Self::SHA512),
@@ -126,6 +134,20 @@ mod test {
     use crate::Integrity;
     use base64::Engine;
     use sha2::Digest;
+    
+    #[cfg(feature = "md5")]
+    #[test]
+    fn try_from_md5() {
+        let value = "alert('Hello, world.');";
+        let digest = md5::Md5::digest(value);
+        let hash = base64::prelude::BASE64_STANDARD.encode(digest);
+        let integrity_value = format!("md5-{hash}");
+        let integrity = Integrity::try_from(integrity_value.as_str()).unwrap();
+
+        assert_eq!(integrity.algorithm, Algorithm::MD5);
+        assert_eq!(integrity.hash, digest.as_slice());
+        assert_eq!(integrity.to_string(), integrity_value)
+    }
 
     #[test]
     fn try_from_sha256() {