1 files changed, 119 insertions, 0 deletions
diff --git a/android/security/keystore/recovery/KeyDerivationParams.java b/android/security/keystore/recovery/KeyDerivationParams.java
new file mode 100644
index 00000000..fc909a0a
--- /dev/null
+++ b/android/security/keystore/recovery/KeyDerivationParams.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2017 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 android.security.keystore.recovery;
+
+import android.annotation.IntDef;
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+
+import com.android.internal.util.Preconditions;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Collection of parameters which define a key derivation function.
+ * Currently only supports salted SHA-256
+ *
+ * @hide
+ */
+@SystemApi
+public final class KeyDerivationParams implements Parcelable {
+    private final int mAlgorithm;
+    private byte[] mSalt;
+
+    /** @hide */
+    @Retention(RetentionPolicy.SOURCE)
+    @IntDef(prefix = {"ALGORITHM_"}, value = {ALGORITHM_SHA256, ALGORITHM_ARGON2ID})
+    public @interface KeyDerivationAlgorithm {
+    }
+
+    /**
+     * Salted SHA256
+     */
+    public static final int ALGORITHM_SHA256 = 1;
+
+    /**
+     * Argon2ID
+     * @hide
+     */
+    // TODO: add Argon2ID support.
+    public static final int ALGORITHM_ARGON2ID = 2;
+
+    /**
+     * Creates instance of the class to to derive key using salted SHA256 hash.
+     */
+    public static KeyDerivationParams createSha256Params(@NonNull byte[] salt) {
+        return new KeyDerivationParams(ALGORITHM_SHA256, salt);
+    }
+
+    /**
+     * @hide
+     */
+    // TODO: Make private once legacy API is removed
+    public KeyDerivationParams(@KeyDerivationAlgorithm int algorithm, @NonNull byte[] salt) {
+        mAlgorithm = algorithm;
+        mSalt = Preconditions.checkNotNull(salt);
+    }
+
+    /**
+     * Gets algorithm.
+     */
+    public @KeyDerivationAlgorithm int getAlgorithm() {
+        return mAlgorithm;
+    }
+
+    /**
+     * Gets salt.
+     */
+    public @NonNull byte[] getSalt() {
+        return mSalt;
+    }
+
+    public static final Parcelable.Creator<KeyDerivationParams> CREATOR =
+            new Parcelable.Creator<KeyDerivationParams>() {
+        public KeyDerivationParams createFromParcel(Parcel in) {
+                return new KeyDerivationParams(in);
+        }
+
+        public KeyDerivationParams[] newArray(int length) {
+            return new KeyDerivationParams[length];
+        }
+    };
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeInt(mAlgorithm);
+        out.writeByteArray(mSalt);
+    }
+
+    /**
+     * @hide
+     */
+    protected KeyDerivationParams(Parcel in) {
+        mAlgorithm = in.readInt();
+        mSalt = in.createByteArray();
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+}