1 files changed, 130 insertions, 0 deletions
diff --git a/ready_se/google/keymint/KM300/Applet/src/com/android/javacard/keymaster/KMRepository.java b/ready_se/google/keymint/KM300/Applet/src/com/android/javacard/keymaster/KMRepository.java
new file mode 100644
index 0000000..9fd2406
--- /dev/null
+++ b/ready_se/google/keymint/KM300/Applet/src/com/android/javacard/keymaster/KMRepository.java
@@ -0,0 +1,130 @@
+/*
+ * Copyright(C) 2020 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.javacard.keymaster;
+
+import javacard.framework.ISO7816;
+import javacard.framework.ISOException;
+import javacard.framework.JCSystem;
+import javacard.framework.Util;
+
+/**
+ * KMRepository class manages volatile memory usage by the applet. Note the repository is only used
+ * by applet and it is not intended to be used by seProvider.
+ */
+public class KMRepository {
+
+  // The maximum available heap memory.
+  public static final short HEAP_SIZE = 10000;
+  // Index pointing from the back of heap.
+  private static short[] reclaimIndex;
+  // Singleton instance
+  private static KMRepository repository;
+  // Heap buffer
+  private byte[] heap;
+  // Index to the heap buffer.
+  private short[] heapIndex;
+
+  public KMRepository(boolean isUpgrading) {
+    heap = JCSystem.makeTransientByteArray(HEAP_SIZE, JCSystem.CLEAR_ON_RESET);
+    heapIndex = JCSystem.makeTransientShortArray((short) 1, JCSystem.CLEAR_ON_RESET);
+    reclaimIndex = JCSystem.makeTransientShortArray((short) 1, JCSystem.CLEAR_ON_RESET);
+    reclaimIndex[0] = HEAP_SIZE;
+    repository = this;
+  }
+
+  public static KMRepository instance() {
+    return repository;
+  }
+
+  public void onUninstall() {
+    // Javacard Runtime environment cleans up the data.
+
+  }
+
+  public void onProcess() {}
+
+  public void clean() {
+    Util.arrayFillNonAtomic(heap, (short) 0, HEAP_SIZE, (byte) 0);
+    heapIndex[0] = 0;
+    reclaimIndex[0] = HEAP_SIZE;
+  }
+
+  public void onDeselect() {}
+
+  public void onSelect() {
+    // If write through caching is implemented then this method will restore the data into cache
+  }
+
+  // This function uses memory from the back of the heap(transient memory). Call
+  // reclaimMemory function immediately after the use.
+  public short allocReclaimableMemory(short length) {
+    if ((((short) (reclaimIndex[0] - length)) <= heapIndex[0]) || (length >= HEAP_SIZE / 2)) {
+      ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
+    }
+    reclaimIndex[0] -= length;
+    return reclaimIndex[0];
+  }
+
+  // Reclaims the memory back.
+  public void reclaimMemory(short length) {
+    if (reclaimIndex[0] < heapIndex[0]) {
+      ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
+    }
+    Util.arrayFillNonAtomic(heap, reclaimIndex[0], length, (byte) 0);
+    reclaimIndex[0] += length;
+  }
+
+  public short allocAvailableMemory() {
+    if (heapIndex[0] >= heap.length) {
+      ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
+    }
+    short index = heapIndex[0];
+    heapIndex[0] = reclaimIndex[0];
+    return index;
+  }
+
+  public short alloc(short length) {
+    if ((((short) (heapIndex[0] + length)) > heap.length)
+        || (((short) (heapIndex[0] + length)) > reclaimIndex[0])) {
+      ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
+    }
+    heapIndex[0] += length;
+    return (short) (heapIndex[0] - length);
+  }
+
+  public byte[] getHeap() {
+    return heap;
+  }
+
+  public short getHeapIndex() {
+    return heapIndex[0];
+  }
+
+  // Use this function to reset the heapIndex to its previous state.
+  // Some of the data might be lost so use it carefully.
+  public void setHeapIndex(short offset) {
+    if (offset > heapIndex[0] || offset < 0) {
+      ISOException.throwIt(ISO7816.SW_CONDITIONS_NOT_SATISFIED);
+    }
+    Util.arrayFillNonAtomic(heap, offset, (short) (heapIndex[0] - offset), (byte) 0);
+    heapIndex[0] = offset;
+  }
+
+  public short getHeapReclaimIndex() {
+    return reclaimIndex[0];
+  }
+}