Sha256 can just be a helper method on SolanaProgramDerivedAddress - i…

…t doesn't need to be it's own class

message-encoding/src/main/java/com/lmax/solana4j/encoding/SolanaProgramDerivedAddress.java

@@ -3,10 +3,11 @@
 import com.lmax.solana4j.api.ProgramDerivedAddress;
 import com.lmax.solana4j.api.PublicKey;
 import com.lmax.solana4j.util.Ed25519;
-import com.lmax.solana4j.util.Sha256;
 
 import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
 import java.util.List;
 import java.util.Objects;
 
@@ -37,7 +38,7 @@ static ProgramDerivedAddress deriveProgramAddress(final List<byte[]> seeds, fina
             programId.write(seedsBuffer);
             seedsBuffer.put(PROGRAM_DERIVED_ADDRESS_BYTES);
 
-            final byte[] programAddress = Sha256.hash(seedsBuffer.array());
+            final byte[] programAddress = hash(seedsBuffer.array());
 
             if (isOffCurve(programAddress))
             {
@@ -48,6 +49,20 @@ static ProgramDerivedAddress deriveProgramAddress(final List<byte[]> seeds, fina
         throw new RuntimeException("Could not find a program address off the curve.");
     }
 
+    private static byte[] hash(final byte[] input)
+    {
+        final MessageDigest digest;
+        try
+        {
+            digest = MessageDigest.getInstance("SHA-256");
+        }
+        catch (final NoSuchAlgorithmException e)
+        {
+            throw new RuntimeException(e);
+        }
+        return digest.digest(input);
+    }
+
     private static boolean isOffCurve(final byte[] programAddress)
     {
         try