add and use constant time 32 byte equality function

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/unit_tests/crypto.cpp b/tests/unit_tests/crypto.cpp
index 9e1680568..29fa88f9d 100644
--- a/tests/unit_tests/crypto.cpp
+++ b/tests/unit_tests/crypto.cpp
@@ -81,3 +81,18 @@ TEST(Crypto, null_keys)
   ASSERT_EQ(memcmp(crypto::null_skey.data, zero, 32), 0);
   ASSERT_EQ(memcmp(crypto::null_pkey.data, zero, 32), 0);
 }
+
+TEST(Crypto, verify_32)
+{
+  // all bytes are treated the same, so we can brute force just one byte
+  unsigned char k0[32] = {0}, k1[32] = {0};
+  for (unsigned int i0 = 0; i0 < 256; ++i0)
+  {
+    k0[0] = i0;
+    for (unsigned int i1 = 0; i1 < 256; ++i1)
+    {
+      k1[0] = i1;
+      ASSERT_EQ(!crypto_verify_32(k0, k1), i0 == i1);
+    }
+  }
+}