1 files changed, 54 insertions, 33 deletions
diff --git a/src/hash.cpp b/src/hash.cpp
index 4ce4da4c3..a7eb5a2a0 100644
--- a/src/hash.cpp
+++ b/src/hash.cpp
@@ -1,4 +1,9 @@
+// Copyright (c) 2013-2014 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 #include "hash.h"
+#include "crypto/hmac_sha512.h"
 
 inline uint32_t ROTL32(uint32_t x, int8_t r)
 {
@@ -9,45 +14,48 @@ unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char
 {
     // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
     uint32_t h1 = nHashSeed;
-    const uint32_t c1 = 0xcc9e2d51;
-    const uint32_t c2 = 0x1b873593;
+    if (vDataToHash.size() > 0)
+    {
+        const uint32_t c1 = 0xcc9e2d51;
+        const uint32_t c2 = 0x1b873593;
 
-    const int nblocks = vDataToHash.size() / 4;
+        const int nblocks = vDataToHash.size() / 4;
 
-    //----------
-    // body
-    const uint32_t* blocks = (const uint32_t*)(&vDataToHash[0] + nblocks * 4);
+        //----------
+        // body
+        const uint32_t* blocks = (const uint32_t*)(&vDataToHash[0] + nblocks * 4);
 
-    for (int i = -nblocks; i; i++) {
-        uint32_t k1 = blocks[i];
+        for (int i = -nblocks; i; i++) {
+            uint32_t k1 = blocks[i];
 
-        k1 *= c1;
-        k1 = ROTL32(k1, 15);
-        k1 *= c2;
+            k1 *= c1;
+            k1 = ROTL32(k1, 15);
+            k1 *= c2;
 
-        h1 ^= k1;
-        h1 = ROTL32(h1, 13);
-        h1 = h1 * 5 + 0xe6546b64;
-    }
+            h1 ^= k1;
+            h1 = ROTL32(h1, 13);
+            h1 = h1 * 5 + 0xe6546b64;
+        }
 
-    //----------
-    // tail
-    const uint8_t* tail = (const uint8_t*)(&vDataToHash[0] + nblocks * 4);
-
-    uint32_t k1 = 0;
-
-    switch (vDataToHash.size() & 3) {
-    case 3:
-        k1 ^= tail[2] << 16;
-    case 2:
-        k1 ^= tail[1] << 8;
-    case 1:
-        k1 ^= tail[0];
-        k1 *= c1;
-        k1 = ROTL32(k1, 15);
-        k1 *= c2;
-        h1 ^= k1;
-    };
+        //----------
+        // tail
+        const uint8_t* tail = (const uint8_t*)(&vDataToHash[0] + nblocks * 4);
+
+        uint32_t k1 = 0;
+
+        switch (vDataToHash.size() & 3) {
+        case 3:
+            k1 ^= tail[2] << 16;
+        case 2:
+            k1 ^= tail[1] << 8;
+        case 1:
+            k1 ^= tail[0];
+            k1 *= c1;
+            k1 = ROTL32(k1, 15);
+            k1 *= c2;
+            h1 ^= k1;
+        };
+    }
 
     //----------
     // finalization
@@ -60,3 +68,16 @@ unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char
 
     return h1;
 }
+
+void BIP32Hash(const unsigned char chainCode[32], unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64])
+{
+    unsigned char num[4];
+    num[0] = (nChild >> 24) & 0xFF;
+    num[1] = (nChild >> 16) & 0xFF;
+    num[2] = (nChild >>  8) & 0xFF;
+    num[3] = (nChild >>  0) & 0xFF;
+    CHMAC_SHA512(chainCode, 32).Write(&header, 1)
+                               .Write(data, 32)
+                               .Write(num, 4)
+                               .Finalize(output);
+}