Add specialization of SipHash for 256 + 32 bit data

We'll need a version of SipHash for tuples of 256 bits and 32 bits
data, when CCoinsViewCache switches from using txids to COutPoints as
keys.

1 files changed, 17 insertions, 0 deletions

diff --git a/src/test/hash_tests.cpp b/src/test/hash_tests.cpp
index d8de765db1..bb7e473248 100644
--- a/src/test/hash_tests.cpp
+++ b/src/test/hash_tests.cpp
@@ -128,6 +128,23 @@ BOOST_AUTO_TEST_CASE(siphash)
     tx.nVersion = 1;
     ss << tx;
     BOOST_CHECK_EQUAL(SipHashUint256(1, 2, ss.GetHash()), 0x79751e980c2a0a35ULL);
+
+    // Check consistency between CSipHasher and SipHashUint256[Extra].
+    FastRandomContext ctx;
+    for (int i = 0; i < 16; ++i) {
+        uint64_t k1 = ctx.rand64();
+        uint64_t k2 = ctx.rand64();
+        uint256 x = GetRandHash();
+        uint32_t n = ctx.rand32();
+        uint8_t nb[4];
+        WriteLE32(nb, n);
+        CSipHasher sip256(k1, k2);
+        sip256.Write(x.begin(), 32);
+        CSipHasher sip288 = sip256;
+        sip288.Write(nb, 4);
+        BOOST_CHECK_EQUAL(SipHashUint256(k1, k2, x), sip256.Finalize());
+        BOOST_CHECK_EQUAL(SipHashUint256Extra(k1, k2, x, n), sip288.Finalize());
+    }
 }
 
 BOOST_AUTO_TEST_SUITE_END()