chore: Move over final neqo-crypt changes (#37)

larseggert · Not-Nik · web-flow · commit 6d4cc4c5ec7c · 2026-04-21T11:35:11.000+02:00
* chore: Move over final neqo-crypt changes I think with this landed, we're ready for cutting 0.0.1 and landing mozilla/neqo#3399. * Add tests for disable-encryption --------- Co-authored-by: Nikolas Wipper <nwipper@mozilla.com>
diff --git a/build.rs b/build.rs
@@ -65,36 +65,70 @@ struct Bindings {
 // bindgen needs access to libclang.
 // On windows, this doesn't just work, you have to set LIBCLANG_PATH.
 // Rather than download the 400Mb+ files, like gecko does, let's just reuse their work.
+// On macOS, clang-sys prefers the highest-versioned libclang it can find, which may be a
+// Homebrew LLVM that doesn't have the correct macOS SDK include paths, resulting in broken
+// bindings. Force use of Xcode's libclang instead.
 fn setup_clang() {
-    // If this isn't Windows, or we're in CI, then we don't need to do anything.
-    if env::consts::OS != "windows" || env::var("GITHUB_WORKFLOW").unwrap_or_default() == "CI" {
+    println!("cargo:rerun-if-env-changed=LIBCLANG_PATH");
+    println!("cargo:rerun-if-env-changed=CI");
+    // In CI, the environment is already configured correctly.
+    if env::var("CI").is_ok() {
         return;
     }
-    println!("rerun-if-env-changed=LIBCLANG_PATH");
-    println!("rerun-if-env-changed=MOZBUILD_STATE_PATH");
     if env::var("LIBCLANG_PATH").is_ok() {
         return;
     }
-    let mozbuild_root = if let Ok(dir) = env::var("MOZBUILD_STATE_PATH") {
-        PathBuf::from(dir.trim())
-    } else {
-        eprintln!("warning: Building without a gecko setup is not likely to work.");
-        eprintln!("         A working libclang is needed to build nss-rs.");
-        eprintln!("         Either LIBCLANG_PATH or MOZBUILD_STATE_PATH needs to be set.");
-        eprintln!();
-        eprintln!("    We recommend checking out https://github.com/mozilla/gecko-dev");
-        eprintln!("    Then run `./mach bootstrap` which will retrieve clang.");
-        eprintln!("    Make sure to export MOZBUILD_STATE_PATH when building.");
-        return;
-    };
-    let libclang_dir = mozbuild_root.join("clang").join("lib");
-    if libclang_dir.is_dir() {
-        unsafe {
-            env::set_var("LIBCLANG_PATH", libclang_dir.to_str().unwrap());
+    if env::consts::OS == "macos" {
+        if let Ok(output) = Command::new("xcode-select").arg("--print-path").output() {
+            if output.status.success() {
+                let xcode_path = String::from_utf8_lossy(&output.stdout).trim().to_string();
+                let candidates = [
+                    PathBuf::from(&xcode_path).join("Toolchains/XcodeDefault.xctoolchain/usr/lib"),
+                    PathBuf::from(&xcode_path).join("usr/lib"),
+                ];
+                if let Some(libclang_dir) = candidates.iter().find(|p| p.is_dir()) {
+                    unsafe {
+                        env::set_var("LIBCLANG_PATH", libclang_dir.to_str().unwrap());
+                    }
+                } else {
+                    println!(
+                        "cargo:warning=Xcode toolchain libclang not found at {}; set LIBCLANG_PATH if build fails",
+                        candidates[0].display()
+                    );
+                }
+            } else {
+                println!(
+                    "cargo:warning=xcode-select returned an error; set LIBCLANG_PATH if build fails"
+                );
+            }
+        } else {
+            println!("cargo:warning=xcode-select not found; set LIBCLANG_PATH if build fails");
+        }
+    } else if env::consts::OS == "windows" {
+        println!("cargo:rerun-if-env-changed=MOZBUILD_STATE_PATH");
+        let mozbuild_root = if let Ok(dir) = env::var("MOZBUILD_STATE_PATH") {
+            PathBuf::from(dir.trim())
+        } else {
+            println!("cargo:warning=Building without a gecko setup is not likely to work.");
+            println!("cargo:warning=A working libclang is needed to build nss-rs.");
+            println!("cargo:warning=Either LIBCLANG_PATH or MOZBUILD_STATE_PATH needs to be set.");
+            println!(
+                "cargo:warning=We recommend checking out https://github.com/mozilla/gecko-dev"
+            );
+            println!("cargo:warning=Then run `./mach bootstrap` which will retrieve clang.");
+            println!("cargo:warning=Make sure to export MOZBUILD_STATE_PATH when building.");
+            return;
+        };
+        let libclang_dir = mozbuild_root.join("clang").join("lib");
+        if libclang_dir.is_dir() {
+            unsafe {
+                env::set_var("LIBCLANG_PATH", libclang_dir.to_str().unwrap());
+            }
+        } else {
+            println!(
+                "cargo:warning=LIBCLANG_PATH isn't set; maybe run ./mach bootstrap with gecko"
+            );
         }
-        println!("rustc-env:LIBCLANG_PATH={}", libclang_dir.to_str().unwrap());
-    } else {
-        println!("warning: LIBCLANG_PATH isn't set; maybe run ./mach bootstrap with gecko");
     }
 }
 
@@ -167,8 +201,7 @@ fn build_nss(dir: PathBuf) {
         // Generate static libraries in addition to shared libraries.
         String::from("--static"),
     ];
-    let target = env::var("TARGET").unwrap();
-    if target.starts_with("aarch64-") {
+    if env::var("CARGO_CFG_TARGET_ARCH").unwrap() == "aarch64" {
         build_nss.push(String::from("--target=arm64"));
     }
     let status = Command::new(get_bash())
@@ -180,7 +213,8 @@ fn build_nss(dir: PathBuf) {
 }
 
 fn dynamic_link() {
-    let dynamic_libs = if env::consts::OS == "windows" {
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    let dynamic_libs = if target_os == "windows" {
         [
             "nssutil3.dll",
             "nss3.dll",
@@ -198,12 +232,13 @@ fn dynamic_link() {
 }
 
 fn static_link() {
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
     let mut static_libs = vec![
         "certdb",
         "certhi",
         "cryptohi",
         "freebl_static",
-        if env::consts::OS == "windows" {
+        if target_os == "windows" {
             "libnspr4"
         } else {
             "nspr4"
@@ -215,12 +250,12 @@ fn static_link() {
         "nsspki",
         "nssutil",
         "pk11wrap_static",
-        if env::consts::OS == "windows" {
+        if target_os == "windows" {
             "libplc4"
         } else {
             "plc4"
         },
-        if env::consts::OS == "windows" {
+        if target_os == "windows" {
             "libplds4"
         } else {
             "plds4"
@@ -230,7 +265,7 @@ fn static_link() {
     ];
     // macOS always dynamically links against the system sqlite library.
     // See https://github.com/nss-dev/nss/blob/a8c22d8fc0458db3e261acc5e19b436ab573a961/coreconf/Darwin.mk#L130-L135
-    if env::consts::OS == "macos" {
+    if target_os == "macos" {
         println!("cargo:rustc-link-lib=dylib=sqlite3");
     } else {
         static_libs.push("sqlite");
@@ -263,11 +298,7 @@ fn static_link() {
 fn get_includes(nsstarget: &Path, nssdist: &Path) -> Vec<PathBuf> {
     let nsprinclude = nsstarget.join("include").join("nspr");
     let nssinclude = nssdist.join("public").join("nss");
-    let includes = vec![nsprinclude, nssinclude];
-    for i in &includes {
-        println!("cargo:include={}", i.to_str().unwrap());
-    }
-    includes
+    vec![nsprinclude, nssinclude]
 }
 
 fn build_bindings(base: &str, bindings: &Bindings, flags: &[String], gecko: bool) {
@@ -285,14 +316,15 @@ fn build_bindings(base: &str, bindings: &Bindings, flags: &[String], gecko: bool
     builder = builder.clang_arg("-v");
 
     if !gecko {
+        let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
         builder = builder.clang_arg("-DNO_NSPR_10_SUPPORT");
-        if env::consts::OS == "windows" {
+        if target_os == "windows" {
             builder = builder.clang_arg("-DWIN");
-        } else if env::consts::OS == "macos" {
+        } else if target_os == "macos" {
             builder = builder.clang_arg("-DDARWIN");
-        } else if env::consts::OS == "linux" {
+        } else if target_os == "linux" {
             builder = builder.clang_arg("-DLINUX");
-        } else if env::consts::OS == "android" {
+        } else if target_os == "android" {
             builder = builder.clang_arg("-DLINUX");
             builder = builder.clang_arg("-DANDROID");
         }
@@ -365,11 +397,9 @@ fn pkg_config() -> Result<Vec<String>, Box<dyn Error>> {
 
     let mut flags: Vec<String> = Vec::new();
 
-    for f in cfg_str.split(' ') {
-        if let Some(include) = f.strip_prefix("-I") {
+    for f in cfg_str.split_whitespace() {
+        if f.starts_with("-I") {
             flags.push(String::from(f));
-
-            println!("cargo:include={include}");
         } else if let Some(path) = f.strip_prefix("-L") {
             println!("cargo:rustc-link-search=native={path}");
         } else if let Some(lib) = f.strip_prefix("-l") {
@@ -383,15 +413,12 @@ fn pkg_config() -> Result<Vec<String>, Box<dyn Error>> {
 }
 
 fn setup_standalone(nss_dir: String) -> Vec<String> {
-    setup_clang();
-
     let nss = PathBuf::from(nss_dir);
-    println!("cargo:rerun-if-env-changed={}", nss.display());
+    println!("cargo:rerun-if-env-changed=NSS_DIR");
     println!("cargo:rerun-if-env-changed=NSS_PREBUILT");
 
     // $NSS_DIR/../dist/
     let nssdist = nss.parent().unwrap().join("dist");
-    println!("cargo:rerun-if-env-changed={}", nssdist.display());
     let nsstarget = "Release";
 
     // If NSS_PREBUILT is set to a non-zero value, we assume that the NSS libraries are already
@@ -411,7 +438,7 @@ fn setup_standalone(nss_dir: String) -> Vec<String> {
     if env::var("CARGO_CFG_FUZZING").is_ok()
         || env::var("PROFILE").unwrap_or_default() == "debug"
         // FIXME: NSPR doesn't build proper dynamic libraries on Windows.
-        || env::consts::OS == "windows"
+        || env::var("CARGO_CFG_TARGET_OS").unwrap() == "windows"
     {
         static_link();
     } else {
@@ -537,7 +564,10 @@ fn process_config(config: &mut HashMap<String, Bindings>) {
 }
 
 fn main() {
+    println!("cargo:rerun-if-changed=src/min_version.rs");
+    println!("cargo:rerun-if-changed=min_version.txt");
     println!("cargo:rustc-check-cfg=cfg(nss_nodb)");
+    setup_clang();
 
     let flags = if cfg!(feature = "gecko") {
         setup_for_gecko()
diff --git a/src/aead.rs b/src/aead.rs
@@ -361,6 +361,95 @@ mod recprot {
             write!(f, "[NULL AEAD]")
         }
     }
+
+    #[cfg(test)]
+    #[cfg_attr(coverage_nightly, coverage(off))]
+    mod tests {
+        use super::{AEAD_NULL_TAG, RecordProtection};
+
+        fn aead() -> RecordProtection {
+            RecordProtection {}
+        }
+
+        #[test]
+        fn expansion() {
+            assert_eq!(aead().expansion(), AEAD_NULL_TAG.len());
+        }
+
+        #[test]
+        fn debug() {
+            assert_eq!(format!("{:?}", aead()), "[NULL AEAD]");
+        }
+
+        #[test]
+        fn encrypt_decrypt_roundtrip() {
+            let a = aead();
+            let plaintext = b"hello world";
+            let mut out = vec![0u8; plaintext.len() + a.expansion()];
+            let encrypted = a.encrypt(0, b"aad", plaintext, &mut out).unwrap();
+            assert_eq!(encrypted.len(), plaintext.len() + a.expansion());
+            assert_eq!(&encrypted[..plaintext.len()], plaintext);
+            assert_eq!(&encrypted[plaintext.len()..], AEAD_NULL_TAG);
+
+            let mut dec_out = vec![0u8; plaintext.len()];
+            let decrypted = a.decrypt(0, b"aad", encrypted, &mut dec_out).unwrap();
+            assert_eq!(decrypted, plaintext);
+        }
+
+        #[test]
+        fn encrypt_in_place_roundtrip() {
+            let a = aead();
+            let plaintext = b"hello";
+            let mut buf = plaintext.to_vec();
+            buf.resize(plaintext.len() + a.expansion(), 0);
+            let len = a.encrypt_in_place(0, b"", &mut buf).unwrap();
+            assert_eq!(len, buf.len());
+            assert_eq!(&buf[plaintext.len()..], AEAD_NULL_TAG);
+
+            let dec_len = a.decrypt_in_place(0, b"", &mut buf).unwrap();
+            assert_eq!(dec_len, plaintext.len());
+            assert_eq!(&buf[..dec_len], plaintext);
+        }
+
+        #[test]
+        fn decrypt_empty_plaintext() {
+            // Zero-length plaintext (just the tag) is valid.
+            let a = aead();
+            let mut out = vec![0u8; a.expansion()];
+            a.encrypt(0, b"", b"", &mut out).unwrap();
+            let mut dec = vec![];
+            let res = a.decrypt(0, b"", &out, &mut dec).unwrap();
+            assert_eq!(res, b"");
+        }
+
+        #[test]
+        fn decrypt_fails_too_short() {
+            let a = aead();
+            let short = &AEAD_NULL_TAG[..a.expansion() - 1];
+            assert!(a.decrypt(0, b"", short, &mut []).is_err());
+        }
+
+        #[test]
+        fn decrypt_fails_bad_tag() {
+            let a = aead();
+            let plaintext = b"test";
+            let mut buf = vec![0u8; plaintext.len() + a.expansion()];
+            a.encrypt(0, b"", plaintext, &mut buf).unwrap();
+            // Corrupt the tag.
+            let tag_start = plaintext.len();
+            buf[tag_start] ^= 0xff;
+            assert!(a.decrypt(0, b"", &buf, &mut []).is_err());
+        }
+
+        #[test]
+        fn decrypt_rejects_all_zero_data_bytes() {
+            // All-zero plaintext with correct tag should fail (looks like padding).
+            let a = aead();
+            let mut buf = vec![0u8; 4 + a.expansion()];
+            buf[4..].copy_from_slice(AEAD_NULL_TAG);
+            assert!(a.decrypt(0, b"", &buf, &mut []).is_err());
+        }
+    }
 }
 
 /// All the nonces are the same length.  Exploit that.
diff --git a/src/constants.rs b/src/constants.rs
@@ -165,3 +165,17 @@ remap_enum! {
         TLS_SIG_RSA_PSS_PSS_SHA512 = ssl_sig_rsa_pss_pss_sha512,
     }
 }
+
+#[cfg(test)]
+#[cfg_attr(coverage_nightly, coverage(off))]
+mod tests {
+    use super::Epoch;
+
+    #[test]
+    fn epoch_into_usize() {
+        assert_eq!(usize::from(Epoch::Initial), 0);
+        assert_eq!(usize::from(Epoch::ZeroRtt), 1);
+        assert_eq!(usize::from(Epoch::Handshake), 2);
+        assert_eq!(usize::from(Epoch::ApplicationData), 3);
+    }
+}
diff --git a/src/err.rs b/src/err.rs
@@ -22,7 +22,7 @@ pub mod nspr {
     include!(concat!(env!("OUT_DIR"), "/nspr_err.rs"));
 }
 
-#[expect(dead_code, reason = "Some constants are not used.")]
+#[cfg_attr(not(test), expect(dead_code, reason = "Some constants are not used."))]
 pub mod mozpkix {
     // These are manually extracted from the many bindings generated
     // by bindgen when provided with the simple header:
@@ -306,4 +306,35 @@ mod tests {
             Error::String
         );
     }
+
+    #[test]
+    fn mozpkix_error_codes_are_negative() {
+        use crate::err::mozpkix::*;
+        let codes = [
+            MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE,
+            MOZILLA_PKIX_ERROR_CA_CERT_USED_AS_END_ENTITY,
+            MOZILLA_PKIX_ERROR_INADEQUATE_KEY_SIZE,
+            MOZILLA_PKIX_ERROR_V1_CERT_USED_AS_CA,
+            MOZILLA_PKIX_ERROR_NO_RFC822NAME_MATCH,
+            MOZILLA_PKIX_ERROR_NOT_YET_VALID_CERTIFICATE,
+            MOZILLA_PKIX_ERROR_NOT_YET_VALID_ISSUER_CERTIFICATE,
+            MOZILLA_PKIX_ERROR_SIGNATURE_ALGORITHM_MISMATCH,
+            MOZILLA_PKIX_ERROR_OCSP_RESPONSE_FOR_CERT_MISSING,
+            MOZILLA_PKIX_ERROR_VALIDITY_TOO_LONG,
+            MOZILLA_PKIX_ERROR_REQUIRED_TLS_FEATURE_MISSING,
+            MOZILLA_PKIX_ERROR_INVALID_INTEGER_ENCODING,
+            MOZILLA_PKIX_ERROR_EMPTY_ISSUER_NAME,
+            MOZILLA_PKIX_ERROR_ADDITIONAL_POLICY_CONSTRAINT_FAILED,
+            MOZILLA_PKIX_ERROR_SELF_SIGNED_CERT,
+            MOZILLA_PKIX_ERROR_MITM_DETECTED,
+            END_OF_LIST,
+        ];
+        for (i, &code) in codes.iter().enumerate() {
+            assert_eq!(
+                code,
+                -16384 + i32::try_from(i).unwrap(),
+                "mozpkix code at index {i}"
+            );
+        }
+    }
 }
