Support SipHash with arbitrary byte writes

1 files changed, 36 insertions, 3 deletions

diff --git a/src/hash.cpp b/src/hash.cpp
index a518314a53..20a83342db 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -100,12 +100,15 @@ CSipHasher::CSipHasher(uint64_t k0, uint64_t k1)
     v[2] = 0x6c7967656e657261ULL ^ k0;
     v[3] = 0x7465646279746573ULL ^ k1;
     count = 0;
+    tmp = 0;
 }
 
 CSipHasher& CSipHasher::Write(uint64_t data)
 {
     uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
 
+    assert(count % 8 == 0);
+
     v3 ^= data;
     SIPROUND;
     SIPROUND;
@@ -116,7 +119,35 @@ CSipHasher& CSipHasher::Write(uint64_t data)
     v[2] = v2;
     v[3] = v3;
 
-    count++;
+    count += 8;
+    return *this;
+}
+
+CSipHasher& CSipHasher::Write(const unsigned char* data, size_t size)
+{
+    uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
+    uint64_t t = tmp;
+    int c = count;
+
+    while (size--) {
+        t |= ((uint64_t)(*(data++))) << (8 * (c % 8));
+        c++;
+        if ((c & 7) == 0) {
+            v3 ^= t;
+            SIPROUND;
+            SIPROUND;
+            v0 ^= t;
+            t = 0;
+        }
+    }
+
+    v[0] = v0;
+    v[1] = v1;
+    v[2] = v2;
+    v[3] = v3;
+    count = c;
+    tmp = t;
+
     return *this;
 }
 
@@ -124,10 +155,12 @@ uint64_t CSipHasher::Finalize() const
 {
     uint64_t v0 = v[0], v1 = v[1], v2 = v[2], v3 = v[3];
 
-    v3 ^= ((uint64_t)count) << 59;
+    uint64_t t = tmp | (((uint64_t)count) << 56);
+
+    v3 ^= t;
     SIPROUND;
     SIPROUND;
-    v0 ^= ((uint64_t)count) << 59;
+    v0 ^= t;
     v2 ^= 0xFF;
     SIPROUND;
     SIPROUND;