Split up crypto/sha2

src/crypto/sha256.h

@@ -0,0 +1,28 @@
+// Copyright (c) 2014 The Bitcoin developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_SHA256_H
+#define BITCOIN_SHA256_H
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/** A hasher class for SHA-256. */
+class CSHA256
+{
+private:
+    uint32_t s[8];
+    unsigned char buf[64];
+    size_t bytes;
+
+public:
+    static const size_t OUTPUT_SIZE = 32;
+
+    CSHA256();
+    CSHA256& Write(const unsigned char* data, size_t len);
+    void Finalize(unsigned char hash[OUTPUT_SIZE]);
+    CSHA256& Reset();
+};
+
+#endif // BITCOIN_SHA256_H