1 files changed, 56 insertions, 0 deletions
diff --git a/src/java/com/android/internal/net/eap/crypto/HmacSha256ByteSigner.java b/src/java/com/android/internal/net/eap/crypto/HmacSha256ByteSigner.java
new file mode 100644
index 00000000..db6e4b30
--- /dev/null
+++ b/src/java/com/android/internal/net/eap/crypto/HmacSha256ByteSigner.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.net.eap.crypto;
+
+import com.android.internal.net.crypto.KeyGenerationUtils;
+import com.android.internal.net.crypto.KeyGenerationUtils.ByteSigner;
+
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ * HmacSha256ByteSigner is a {@link ByteSigner} to be used for computing HMAC-SHA-256 values for
+ * specific keys and data.
+ */
+public class HmacSha256ByteSigner implements KeyGenerationUtils.ByteSigner {
+    private static final String TAG = HmacSha256ByteSigner.class.getSimpleName();
+    private static final String MAC_ALGORITHM_STRING = "HmacSHA256";
+    private static final HmacSha256ByteSigner sInstance = new HmacSha256ByteSigner();
+
+    /**
+     * Gets instance of HmacSha256ByteSigner.
+     *
+     * @return HmacSha256ByteSigner instance.
+     */
+    public static HmacSha256ByteSigner getInstance() {
+        return sInstance;
+    }
+
+    @Override
+    public byte[] signBytes(byte[] keyBytes, byte[] dataToSign) {
+        try {
+            Mac mac = Mac.getInstance(MAC_ALGORITHM_STRING);
+            mac.init(new SecretKeySpec(keyBytes, MAC_ALGORITHM_STRING));
+            return mac.doFinal(dataToSign);
+        } catch (NoSuchAlgorithmException | InvalidKeyException ex) {
+            throw new IllegalArgumentException(ex);
+        }
+    }
+}