[sync] Upstream the Android ProfileSyncService

chrome/android/java/src/org/chromium/chrome/browser/util/HashUtil.java

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.util;
+
+import android.util.Log;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Formatter;
+
+import javax.annotation.Nullable;
+
+/**
+ * Helper functions for working with hashes.
+ */
+public final class HashUtil {
+    private static final String TAG = HashUtil.class.getSimpleName();
+
+    private HashUtil() {
+    }
+
+    public static class Params {
+        private final String mText;
+        private String mSalt;
+
+        public Params(String text) {
+            mText = text;
+        }
+
+        public Params withSalt(String salt) {
+            mSalt = salt;
+            return this;
+        }
+    }
+
+    public static String getMd5Hash(Params params) {
+        return getHash(params, "MD5");
+    }
+
+    private static String getHash(Params params, String algorithm) {
+        try {
+            String digestText = params.mText + (params.mSalt == null ? "" : params.mSalt);
+            MessageDigest m = MessageDigest.getInstance(algorithm);
+            byte[] digest = m.digest(digestText.getBytes());
+            return encodeHex(digest);
+        } catch (NoSuchAlgorithmException e) {
+            Log.e(TAG, "Unable to find digest algorithm " + algorithm);
+            return null;
+        }
+    }
+
+    private static String encodeHex(byte[] data) {
+        StringBuilder sb = new StringBuilder(data.length * 2);
+        Formatter formatter = new Formatter(sb);
+        for (byte b : data) {
+            formatter.format("%02x", b);
+        }
+        return sb.toString();
+    }
+}