tests: add JA4 pcap tests (aws#4714)

.github/workflows/ci_rust.yml

@@ -272,7 +272,7 @@ jobs:
         run: grep "rust-version = \"$(cat ${{env.ROOT_PATH}}/rust-toolchain)\"" ${{env.ROOT_PATH}}/s2n-tls-tokio/Cargo.toml
 
   pcaps:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v3
         with:
@@ -285,7 +285,9 @@ jobs:
           rustup override set stable
 
       - name: Install tshark
-        run: sudo apt-get install -y tshark
+        run: |
+          sudo apt-get install -y tshark
+          tshark --version
 
       - name: Generate bindings
         working-directory: ${{env.ROOT_PATH}}
@@ -299,4 +301,4 @@ jobs:
 
       - name: Run tests
         working-directory: ${{env.PCAP_TEST_PATH}}
-        run: cargo test
+        run: cargo test --all-features

tests/pcap/Cargo.toml

@@ -4,6 +4,10 @@ version = "0.1.0"
 edition = "2021"
 publish = false
 
+[features]
+default = []
+ja4 = [] # Older versions of tshark do not support JA4
+
 [dependencies]
 anyhow = "1.0.86"
 hex = "0.4.3"

tests/pcap/src/client_hello.rs

@@ -23,6 +23,16 @@ impl ClientHello {
         self.0.packet.metadata(Self::JA3_STR).map(str::to_owned)
     }
 
+    const JA4_HASH: &'static str = "tls.handshake.ja4";
+    pub fn ja4_hash(&self) -> Option<String> {
+        self.0.packet.metadata(Self::JA4_HASH).map(str::to_owned)
+    }
+
+    const JA4_STR: &'static str = "tls.handshake.ja4_r";
+    pub fn ja4_string(&self) -> Option<String> {
+        self.0.packet.metadata(Self::JA4_STR).map(str::to_owned)
+    }
+
     pub fn message(&self) -> &HandshakeMessage {
         &self.0
     }

tests/pcap/tests/s2n_client_hellos.rs

@@ -14,9 +14,9 @@ fn get_s2n_hello(pcap_hello: &PcapHello) -> Result<Box<S2NHello>> {
     Ok(r?)
 }
 
-fn test_all_client_hellos<F>(test_fn: F) -> Result<()>
+fn test_all_client_hellos<F>(mut test_fn: F) -> Result<()>
 where
-    F: FnOnce(PcapHello, Box<S2NHello>) -> Result<()> + Copy,
+    F: FnMut(PcapHello, Box<S2NHello>) -> Result<()>,
 {
     let pcaps = all_pcaps();
     for pcap in pcaps {
@@ -62,3 +62,29 @@ fn ja3_fingerprints() -> Result<()> {
         Ok(())
     })
 }
+
+#[cfg(feature = "ja4")]
+#[test]
+fn ja4_fingerprints() -> Result<()> {
+    use s2n_tls::fingerprint;
+
+    let mut builder = fingerprint::Builder::new(FingerprintType::JA4)?;
+
+    test_all_client_hellos(|pcap_hello, s2n_hello| {
+        let mut fingerprint = builder.build(&s2n_hello)?;
+
+        let s2n_ja4_hash = fingerprint
+            .hash()
+            .context("s2n failed to calculate ja4 hash")?
+            .to_owned();
+
+        let s2n_ja4_str = fingerprint
+            .raw()
+            .context("s2n failed to calculate ja4 string")?
+            .to_owned();
+
+        assert_eq!(pcap_hello.ja4_hash(), Some(s2n_ja4_hash));
+        assert_eq!(pcap_hello.ja4_string(), Some(s2n_ja4_str));
+        Ok(())
+    })
+}