[PAC] Add unit tests for sip hash

Author: jchlanda

compiler/rustc_middle/src/ptrauth/discriminator.rs

@@ -48,8 +48,8 @@ The computation is structured into three conceptual stages:
 
 - High-level API
   - `FnPtrDiscriminatorSource`
-  - `compute_fn_ptr_type_discriminator_for`
-  - `clone_discriminated_ptrauth_schema_for`
+  - `ptrauth_compute_fn_ptr_type_discriminator_for`
+  - `ptrauth_clone_discriminated_schema_for`
 
 - Low-level API
   - `FnPtrTypeDiscriminatorInput`
@@ -163,7 +163,10 @@ impl<'tcx> FnPtrDiscriminatorSource<'tcx> for ty::FnSig<'tcx> {
 ///
 /// Returns `None` if the supplied source does not represent a function pointer
 /// type (for example, a non-function `Ty`).
-pub fn compute_fn_ptr_type_discriminator_for<'tcx, S>(tcx: TyCtxt<'tcx>, source: S) -> Option<u16>
+pub fn ptrauth_compute_fn_ptr_type_discriminator_for<'tcx, S>(
+    tcx: TyCtxt<'tcx>,
+    source: S,
+) -> Option<u16>
 where
     S: FnPtrDiscriminatorSource<'tcx>,
 {
@@ -184,7 +187,7 @@ where
 /// This is intended as a convenience helper for code generation sites that need
 /// to attach function pointer type discrimination to a generic schema before
 /// calling `get_fn_addr`.
-pub fn clone_discriminated_ptrauth_schema_for<'tcx, S>(
+pub fn ptrauth_clone_discriminated_schema_for<'tcx, S>(
     tcx: TyCtxt<'tcx>,
     mut schema: Option<PointerAuthSchema>,
     source: S,
@@ -193,7 +196,7 @@ where
     S: FnPtrDiscriminatorSource<'tcx>,
 {
     if let Some(ref mut s) = schema {
-        if let Some(disc) = compute_fn_ptr_type_discriminator_for(tcx, source) {
+        if let Some(disc) = ptrauth_compute_fn_ptr_type_discriminator_for(tcx, source) {
             s.constant_discriminator = disc;
         }
     }

compiler/rustc_middle/src/ptrauth/llvm_siphash/llvm_siphash_vectors.rs

@@ -0,0 +1,68 @@
+pub(super) const TEST_KEY: [u8; 16] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
+
+pub(super) const EXPECTED64: [[u8; 8]; 64] = [
+    [0x31, 0x0e, 0x0e, 0xdd, 0x47, 0xdb, 0x6f, 0x72],
+    [0xfd, 0x67, 0xdc, 0x93, 0xc5, 0x39, 0xf8, 0x74],
+    [0x5a, 0x4f, 0xa9, 0xd9, 0x09, 0x80, 0x6c, 0x0d],
+    [0x2d, 0x7e, 0xfb, 0xd7, 0x96, 0x66, 0x67, 0x85],
+    [0xb7, 0x87, 0x71, 0x27, 0xe0, 0x94, 0x27, 0xcf],
+    [0x8d, 0xa6, 0x99, 0xcd, 0x64, 0x55, 0x76, 0x18],
+    [0xce, 0xe3, 0xfe, 0x58, 0x6e, 0x46, 0xc9, 0xcb],
+    [0x37, 0xd1, 0x01, 0x8b, 0xf5, 0x00, 0x02, 0xab],
+    [0x62, 0x24, 0x93, 0x9a, 0x79, 0xf5, 0xf5, 0x93],
+    [0xb0, 0xe4, 0xa9, 0x0b, 0xdf, 0x82, 0x00, 0x9e],
+    [0xf3, 0xb9, 0xdd, 0x94, 0xc5, 0xbb, 0x5d, 0x7a],
+    [0xa7, 0xad, 0x6b, 0x22, 0x46, 0x2f, 0xb3, 0xf4],
+    [0xfb, 0xe5, 0x0e, 0x86, 0xbc, 0x8f, 0x1e, 0x75],
+    [0x90, 0x3d, 0x84, 0xc0, 0x27, 0x56, 0xea, 0x14],
+    [0xee, 0xf2, 0x7a, 0x8e, 0x90, 0xca, 0x23, 0xf7],
+    [0xe5, 0x45, 0xbe, 0x49, 0x61, 0xca, 0x29, 0xa1],
+    [0xdb, 0x9b, 0xc2, 0x57, 0x7f, 0xcc, 0x2a, 0x3f],
+    [0x94, 0x47, 0xbe, 0x2c, 0xf5, 0xe9, 0x9a, 0x69],
+    [0x9c, 0xd3, 0x8d, 0x96, 0xf0, 0xb3, 0xc1, 0x4b],
+    [0xbd, 0x61, 0x79, 0xa7, 0x1d, 0xc9, 0x6d, 0xbb],
+    [0x98, 0xee, 0xa2, 0x1a, 0xf2, 0x5c, 0xd6, 0xbe],
+    [0xc7, 0x67, 0x3b, 0x2e, 0xb0, 0xcb, 0xf2, 0xd0],
+    [0x88, 0x3e, 0xa3, 0xe3, 0x95, 0x67, 0x53, 0x93],
+    [0xc8, 0xce, 0x5c, 0xcd, 0x8c, 0x03, 0x0c, 0xa8],
+    [0x94, 0xaf, 0x49, 0xf6, 0xc6, 0x50, 0xad, 0xb8],
+    [0xea, 0xb8, 0x85, 0x8a, 0xde, 0x92, 0xe1, 0xbc],
+    [0xf3, 0x15, 0xbb, 0x5b, 0xb8, 0x35, 0xd8, 0x17],
+    [0xad, 0xcf, 0x6b, 0x07, 0x63, 0x61, 0x2e, 0x2f],
+    [0xa5, 0xc9, 0x1d, 0xa7, 0xac, 0xaa, 0x4d, 0xde],
+    [0x71, 0x65, 0x95, 0x87, 0x66, 0x50, 0xa2, 0xa6],
+    [0x28, 0xef, 0x49, 0x5c, 0x53, 0xa3, 0x87, 0xad],
+    [0x42, 0xc3, 0x41, 0xd8, 0xfa, 0x92, 0xd8, 0x32],
+    [0xce, 0x7c, 0xf2, 0x72, 0x2f, 0x51, 0x27, 0x71],
+    [0xe3, 0x78, 0x59, 0xf9, 0x46, 0x23, 0xf3, 0xa7],
+    [0x38, 0x12, 0x05, 0xbb, 0x1a, 0xb0, 0xe0, 0x12],
+    [0xae, 0x97, 0xa1, 0x0f, 0xd4, 0x34, 0xe0, 0x15],
+    [0xb4, 0xa3, 0x15, 0x08, 0xbe, 0xff, 0x4d, 0x31],
+    [0x81, 0x39, 0x62, 0x29, 0xf0, 0x90, 0x79, 0x02],
+    [0x4d, 0x0c, 0xf4, 0x9e, 0xe5, 0xd4, 0xdc, 0xca],
+    [0x5c, 0x73, 0x33, 0x6a, 0x76, 0xd8, 0xbf, 0x9a],
+    [0xd0, 0xa7, 0x04, 0x53, 0x6b, 0xa9, 0x3e, 0x0e],
+    [0x92, 0x59, 0x58, 0xfc, 0xd6, 0x42, 0x0c, 0xad],
+    [0xa9, 0x15, 0xc2, 0x9b, 0xc8, 0x06, 0x73, 0x18],
+    [0x95, 0x2b, 0x79, 0xf3, 0xbc, 0x0a, 0xa6, 0xd4],
+    [0xf2, 0x1d, 0xf2, 0xe4, 0x1d, 0x45, 0x35, 0xf9],
+    [0x87, 0x57, 0x75, 0x19, 0x04, 0x8f, 0x53, 0xa9],
+    [0x10, 0xa5, 0x6c, 0xf5, 0xdf, 0xcd, 0x9a, 0xdb],
+    [0xeb, 0x75, 0x09, 0x5c, 0xcd, 0x98, 0x6c, 0xd0],
+    [0x51, 0xa9, 0xcb, 0x9e, 0xcb, 0xa3, 0x12, 0xe6],
+    [0x96, 0xaf, 0xad, 0xfc, 0x2c, 0xe6, 0x66, 0xc7],
+    [0x72, 0xfe, 0x52, 0x97, 0x5a, 0x43, 0x64, 0xee],
+    [0x5a, 0x16, 0x45, 0xb2, 0x76, 0xd5, 0x92, 0xa1],
+    [0xb2, 0x74, 0xcb, 0x8e, 0xbf, 0x87, 0x87, 0x0a],
+    [0x6f, 0x9b, 0xb4, 0x20, 0x3d, 0xe7, 0xb3, 0x81],
+    [0xea, 0xec, 0xb2, 0xa3, 0x0b, 0x22, 0xa8, 0x7f],
+    [0x99, 0x24, 0xa4, 0x3c, 0xc1, 0x31, 0x57, 0x24],
+    [0xbd, 0x83, 0x8d, 0x3a, 0xaf, 0xbf, 0x8d, 0xb7],
+    [0x0b, 0x1a, 0x2a, 0x32, 0x65, 0xd5, 0x1a, 0xea],
+    [0x13, 0x50, 0x79, 0xa3, 0x23, 0x1c, 0xe6, 0x60],
+    [0x93, 0x2b, 0x28, 0x46, 0xe4, 0xd7, 0x06, 0x66],
+    [0xe1, 0x91, 0x5f, 0x5c, 0xb1, 0xec, 0xa4, 0x6c],
+    [0xf3, 0x25, 0x96, 0x5c, 0xa1, 0x6d, 0x62, 0x9f],
+    [0x57, 0x5f, 0xf2, 0x8e, 0x60, 0x38, 0x1b, 0xe5],
+    [0x72, 0x45, 0x06, 0xeb, 0x4c, 0x32, 0x8a, 0x95],
+];

…rustc_middle/src/ptrauth/llvm_siphash.rs …c_middle/src/ptrauth/llvm_siphash/mod.rscompiler/rustc_middle/src/ptrauth/llvm_siphash.rs renamed to compiler/rustc_middle/src/ptrauth/llvm_siphash/mod.rs compiler/rustc_middle/src/ptrauth/llvm_siphash.rs renamed to compiler/rustc_middle/src/ptrauth/llvm_siphash/mod.rs

@@ -1,4 +1,4 @@
-// LLVM SipHash-2-4
+// LLVM SipHash-2-4 (64 bit version)
 pub fn llvm_pointer_auth_stable_siphash(data: &[u8]) -> u16 {
     let raw = llvm_siphash_2_4_64(data);
 
@@ -91,10 +91,9 @@ fn load_u64_partial(bytes: &[u8]) -> u64 {
     b
 }
 
-// LLVM siphash<2,4> 64-bit output
-fn llvm_siphash_2_4_64(data: &[u8]) -> u64 {
-    let k0 = u64_from_le(&SIPHASH_KEY[0..8]);
-    let k1 = u64_from_le(&SIPHASH_KEY[8..16]);
+fn siphash_2_4_64_with_key(data: &[u8], key: &[u8; 16]) -> u64 {
+    let k0 = u64_from_le(&key[0..8]);
+    let k1 = u64_from_le(&key[8..16]);
 
     let mut v0: u64 = 0x736f6d6570736575 ^ k0;
     let mut v1: u64 = 0x646f72616e646f6d ^ k1;
@@ -140,3 +139,13 @@ fn llvm_siphash_2_4_64(data: &[u8]) -> u64 {
 
     v0 ^ v1 ^ v2 ^ v3
 }
+// LLVM siphash<2,4> 64-bit output
+fn llvm_siphash_2_4_64(data: &[u8]) -> u64 {
+    siphash_2_4_64_with_key(data, &SIPHASH_KEY)
+}
+
+#[cfg(test)]
+mod llvm_siphash_vectors;
+
+#[cfg(test)]
+mod tests;

compiler/rustc_middle/src/ptrauth/llvm_siphash/tests.rs

@@ -0,0 +1,55 @@
+use llvm_siphash_vectors::{EXPECTED64, TEST_KEY};
+
+use super::*;
+
+// These tests mirror the SipHash tests from LLVM's Support/SipHashTest.cpp.
+// The implementation here is a faithful Rust translation of the LLVM 64-bit
+// SipHash-2-4 implementation used for pointer authentication discriminators.
+//
+// TEST_KEY and EXPECTED64 are copied from the upstream SipHash reference
+// vectors. Keeping these values identical ensures that the Rust implementation
+// produces the same SipHash output as LLVM.
+//
+// Run with:
+//   x.py test compiler/rustc_middle --test-args siphash
+
+#[test]
+fn siphash24_reference_vectors_64() {
+    // Validate the SipHash-2-4 implementation against the upstream SipHash
+    // reference vectors.
+    //
+    // Each input is the byte sequence [0, 1, ..., len-1] and is hashed using
+    // the reference key TEST_KEY ([0, 1, ..., 15]). The expected values are
+    // compared byte-for-byte with the LLVM reference implementation output
+    // (EXPECTED64).
+    //
+    // This test verifies the correctness of the SipHash primitive itself,
+    // independently of the pointer authentication discriminator logic.
+    let mut input = [0u8; 64];
+
+    for len in 0..EXPECTED64.len() {
+        input[len] = len as u8;
+
+        let hash = siphash_2_4_64_with_key(&input[..len], &TEST_KEY);
+
+        assert_eq!(hash.to_le_bytes(), EXPECTED64[len]);
+    }
+}
+
+#[test]
+fn pointer_auth_stable_siphash() {
+    // Validate the rustc pointer-authentication SipHash wrapper against the
+    // values used by the LLVM implementation.
+    //
+    // The returned value is a 16-bit discriminator derived from the stable
+    // SipHash-2-4 output.
+    assert_eq!(llvm_pointer_auth_stable_siphash(b""), 0xE793);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"strlen"), 0xF468);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"_ZN1 ind; f"), 0x2D15);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"isa"), 0x6AE1);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"objc_class:superclass"), 0xB5AB,);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"block_descriptor"), 0xC0BB,);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"method_list_t"), 0xC310,);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"_Zptrkvttf"), 1);
+    assert_eq!(llvm_pointer_auth_stable_siphash(b"_Zaflhllod"), 0xFFFF);
+}

compiler/rustc_middle/src/ptrauth/mod.rs

@@ -2,6 +2,6 @@ pub mod discriminator;
 pub mod llvm_siphash;
 
 pub use discriminator::{
-    FnPtrDiscriminatorSource, FnPtrTypeDiscriminatorInput, clone_discriminated_ptrauth_schema_for,
-    compute_fn_ptr_type_discriminator_for,
+    FnPtrDiscriminatorSource, FnPtrTypeDiscriminatorInput, ptrauth_clone_discriminated_schema_for,
+    ptrauth_compute_fn_ptr_type_discriminator_for,
 };

src/doc/rustc/src/platform-support/aarch64-unknown-linux-pauthtest.md

@@ -474,18 +474,20 @@ The following categories are supported (all present in tree):
   * invalid_target_pointer_authentication.rs
   * type_discrimination_not_supported_pointer_authentication.rs
   * incompatible_pauth.rs
+* Unit tests for siphash function:
+  * compiler/rustc_middle/src/ptrauth/llvm_siphash/tests.rs
 
 All tests from `assembly-llvm`, `codegen-llvm`, `codegen-units`, `coverage`,
-`crashes`, `incremental`, `library`, `mir-opt`, `run-make`, `ui` and
-`ui-fulldeps` subsets are expected to pass.
+`crashes`, `incremental`, `library`, `mir-opt`, `run-make`, `rust_middle` `ui`
+and `ui-fulldeps` subsets are expected to pass.
 
 Command to run all passing tests (with tests added by this target explicitly
 named for convenience):
 
 ```sh
 x.py test --target aarch64-unknown-linux-pauthtest --force-rerun assembly-llvm \
   codegen-llvm codegen-units coverage crashes incremental library mir-opt \
-  run-make ui ui-fulldeps \
+  run-make rust_middle ui ui-fulldeps \
   tests/assembly-llvm/pauth-basic.rs \
   tests/codegen-llvm/pauth/pauth-attr-cli-flags.rs \
   tests/codegen-llvm/pauth/pauth-attr-special-funcs.rs \