Add blake2b writer.

furszy · furszy · commit 6dfc4d2e9173 · 2020-08-02T23:03:32.000-03:00
diff --git a/src/hash.h b/src/hash.h
@@ -28,6 +28,8 @@
 #include <sstream>
 #include <vector>
 
+#include <sodium.h>
+
 
 typedef uint256 ChainCode;
 
@@ -311,6 +313,45 @@ class CHashWriter
     }
 };
 
+/** A writer stream (for serialization) that computes a 256-bit BLAKE2b hash. */
+class CBLAKE2bWriter
+{
+private:
+    crypto_generichash_blake2b_state state;
+
+public:
+    int nType;
+    int nVersion;
+
+    CBLAKE2bWriter(int nTypeIn, int nVersionIn, const unsigned char* personal) : nType(nTypeIn), nVersion(nVersionIn) {
+        assert(crypto_generichash_blake2b_init_salt_personal(
+            &state,
+            NULL, 0, // No key.
+            32,
+            NULL,    // No salt.
+            personal) == 0);
+    }
+
+    CBLAKE2bWriter& write(const char *pch, size_t size) {
+        crypto_generichash_blake2b_update(&state, (const unsigned char*)pch, size);
+        return (*this);
+    }
+
+    // invalidates the object
+    uint256 GetHash() {
+        uint256 result;
+        crypto_generichash_blake2b_final(&state, (unsigned char*)&result, 32);
+        return result;
+    }
+
+    template<typename T>
+    CBLAKE2bWriter& operator<<(const T& obj) {
+        // Serialize to this stream
+        ::Serialize(*this, obj, nType, nVersion);
+        return (*this);
+    }
+};
+
 /** Compute the 256-bit hash of an object's serialization. */
 template <typename T>
 uint256 SerializeHash(const T& obj, int nType = SER_GETHASH, int nVersion = PROTOCOL_VERSION)
