Fix SipHash for big-endian (aws#1251)

andrewhop · Oct 20, 2023 · dc888d5 · dc888d5
1 parent 642e71f
commit dc888d5
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Showing 2 changed files with 17 additions and 10 deletions.
diff --git a/crypto/siphash/siphash.c b/crypto/siphash/siphash.c
@@ -41,11 +41,18 @@ uint64_t SIPHASH_24(const uint64_t key[2], const uint8_t *input,
                     size_t input_len) {
   const size_t orig_input_len = input_len;
 
-  uint64_t v[4];
-  v[0] = key[0] ^ UINT64_C(0x736f6d6570736575);
-  v[1] = key[1] ^ UINT64_C(0x646f72616e646f6d);
-  v[2] = key[0] ^ UINT64_C(0x6c7967656e657261);
-  v[3] = key[1] ^ UINT64_C(0x7465646279746573);
+  uint64_t v[4], k0, k1;
+#ifdef OPENSSL_BIG_ENDIAN
+  k0 = CRYPTO_bswap8(key[0]);
+  k1 = CRYPTO_bswap8(key[1]);
+#else
+  k0 = key[0];
+  k1 = key[1];
+#endif
+  v[0] = k0 ^ UINT64_C(0x736f6d6570736575);
+  v[1] = k1 ^ UINT64_C(0x646f72616e646f6d);
+  v[2] = k0 ^ UINT64_C(0x6c7967656e657261);
+  v[3] = k1 ^ UINT64_C(0x7465646279746573);
 
   while (input_len >= sizeof(uint64_t)) {
     uint64_t m = CRYPTO_load_u64_le(input);

diff --git a/crypto/siphash/siphash_test.cc b/crypto/siphash/siphash_test.cc
@@ -41,17 +41,17 @@ TEST(SipHash, Basic) {
 
 TEST(SipHash, Vectors) {
   FileTestGTest("crypto/siphash/siphash_tests.txt", [](FileTest *t) {
-    std::vector<uint8_t> key, msg, hash;
+    std::vector<uint8_t> key, msg, hash_bytes;
     ASSERT_TRUE(t->GetBytes(&key, "KEY"));
     ASSERT_TRUE(t->GetBytes(&msg, "IN"));
-    ASSERT_TRUE(t->GetBytes(&hash, "HASH"));
+    ASSERT_TRUE(t->GetBytes(&hash_bytes, "HASH"));
     ASSERT_EQ(16u, key.size());
-    ASSERT_EQ(8u, hash.size());
+    ASSERT_EQ(8u, hash_bytes.size());
+    uint64_t hash = CRYPTO_load_u64_le(hash_bytes.data());
 
     uint64_t key_words[2];
     memcpy(key_words, key.data(), key.size());
     uint64_t result = SIPHASH_24(key_words, msg.data(), msg.size());
-    EXPECT_EQ(Bytes(reinterpret_cast<uint8_t *>(&result), sizeof(result)),
-              Bytes(hash));
+    EXPECT_EQ(result, hash);
   });
 }