1 files changed, 58 insertions, 1 deletions

diff --git a/crypto/poly1305/poly1305_test.cc b/crypto/poly1305/poly1305_test.cc
index cae30a42..2c25e93b 100644
--- a/crypto/poly1305/poly1305_test.cc
+++ b/crypto/poly1305/poly1305_test.cc
@@ -24,6 +24,54 @@
 #include "../test/file_test.h"
 
 
+static bool TestSIMD(FileTest *t, unsigned excess,
+                     const std::vector<uint8_t> &key,
+                     const std::vector<uint8_t> &in,
+                     const std::vector<uint8_t> &mac) {
+  poly1305_state state;
+  CRYPTO_poly1305_init(&state, key.data());
+
+  size_t done = 0;
+
+  // Feed 16 bytes in. Some implementations begin in non-SIMD mode and upgrade
+  // on-demand. Stress the upgrade path.
+  size_t todo = 16;
+  if (todo > in.size()) {
+    todo = in.size();
+  }
+  CRYPTO_poly1305_update(&state, in.data(), todo);
+  done += todo;
+
+  for (;;) {
+    // Feed 128 + |excess| bytes to test SIMD mode.
+    if (done + 128 + excess > in.size()) {
+      break;
+    }
+    CRYPTO_poly1305_update(&state, in.data() + done, 128 + excess);
+    done += 128 + excess;
+
+    // Feed |excess| bytes to ensure SIMD mode can handle short inputs.
+    if (done + excess > in.size()) {
+      break;
+    }
+    CRYPTO_poly1305_update(&state, in.data() + done, excess);
+    done += excess;
+  }
+
+  // Consume the remainder and finish.
+  CRYPTO_poly1305_update(&state, in.data() + done, in.size() - done);
+
+  // |CRYPTO_poly1305_finish| requires a 16-byte-aligned output.
+  alignas(16) uint8_t out[16];
+  CRYPTO_poly1305_finish(&state, out);
+  if (!t->ExpectBytesEqual(mac.data(), mac.size(), out, 16)) {
+    t->PrintLine("SIMD pattern %u failed.", excess);
+    return false;
+  }
+
+  return true;
+}
+
 static bool TestPoly1305(FileTest *t, void *arg) {
   std::vector<uint8_t> key, in, mac;
   if (!t->GetBytes(&key, "Key") ||
@@ -54,11 +102,20 @@ static bool TestPoly1305(FileTest *t, void *arg) {
     CRYPTO_poly1305_update(&state, &in[i], 1);
   }
   CRYPTO_poly1305_finish(&state, out);
-  if (!t->ExpectBytesEqual(out, 16, mac.data(), mac.size())) {
+  if (!t->ExpectBytesEqual(mac.data(), mac.size(), out, 16)) {
     t->PrintLine("Streaming Poly1305 failed.");
     return false;
   }
 
+  // Test SIMD stress patterns. OpenSSL's AVX2 assembly needs a multiple of
+  // four blocks, so test up to three blocks of excess.
+  if (!TestSIMD(t, 0, key, in, mac) ||
+      !TestSIMD(t, 16, key, in, mac) ||
+      !TestSIMD(t, 32, key, in, mac) ||
+      !TestSIMD(t, 48, key, in, mac)) {
+    return false;
+  }
+
   return true;
 }