Implementation of VerusHash CPU-friendly hash algorithm, parameters to enable it, miner, and all changes required to support it on new asset chains

src/crypto/verus_hash.cpp

@@ -0,0 +1,75 @@
+// (C) 2018 The Verus Developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+/*
+This provides the PoW hash function for Verus, a CPU-optimized hash 
+function with a Haraka V2 core. Unlike Haraka, which is made for short 
+inputs only, Verus Hash takes any length of input and produces a 256 
+bit output.
+*/
+#include <string.h>
+#include "crypto/common.h"
+#include "crypto/verus_hash.h"
+
+void CVerusHash::Hash(void *result, const void *data, size_t len)
+{
+    unsigned char buf[128];
+    unsigned char *bufPtr = buf;
+    int pos = 0, nextOffset = 64;
+    unsigned char *bufPtr2 = bufPtr + nextOffset;
+    unsigned char *ptr = (unsigned char *)data;
+
+    // put our last result or zero at beginning of buffer each time
+    memset(bufPtr, 0, 32);
+
+    // digest up to 32 bytes at a time
+    for ( ; pos < len; pos += 32)
+    {
+        if (len - pos >= 32)
+        {
+            memcpy(bufPtr + 32, ptr + pos, 32);
+        }
+        else
+        {
+            int i = (int)(len - pos);
+            memcpy(bufPtr + 32, ptr + pos, i);
+            memset(bufPtr + 32 + i, 0, 32 - i);
+        }
+        haraka512(bufPtr2, bufPtr);
+        bufPtr2 = bufPtr;
+        bufPtr += nextOffset;
+        nextOffset *= -1;
+    }
+    memcpy(result, bufPtr, 32);
+};
+
+CVerusHash &CVerusHash::Write(const unsigned char *data, size_t len)
+{
+    unsigned char *tmp;
+
+    // digest up to 32 bytes at a time
+    for ( int pos = 0; pos < len; pos += 32)
+    {
+        int room = 32 - curPos;
+
+        if (len - pos >= room)
+        {
+            memcpy(curBuf + 32 + curPos, data + pos, room);
+            haraka512(result, curBuf);
+            tmp = curBuf;
+            curBuf = result;
+            result = tmp;
+            pos += room;
+            curPos = 0;
+        }
+        else
+        {
+            memcpy(curBuf + 32 + curPos, data + pos, len - pos);
+            curPos = 32 - (len - pos);
+            pos = len;
+        }
+    }
+    return *this;
+}
+