1 files changed, 65 insertions, 0 deletions
diff --git a/libdex/Leb128.cpp b/libdex/Leb128.cpp
new file mode 100644
index 000000000..ed09e19aa
--- /dev/null
+++ b/libdex/Leb128.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2008 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.
+ */
+
+/*
+ * Functions for interpreting LEB128 (little endian base 128) values
+ */
+
+#include "Leb128.h"
+
+/*
+ * Reads an unsigned LEB128 value, updating the given pointer to point
+ * just past the end of the read value and also indicating whether the
+ * value was syntactically valid. The only syntactically *invalid*
+ * values are ones that are five bytes long where the final byte has
+ * any but the low-order four bits set. Additionally, if the limit is
+ * passed as non-NULL and bytes would need to be read past the limit,
+ * then the read is considered invalid.
+ */
+int readAndVerifyUnsignedLeb128(const u1** pStream, const u1* limit,
+        bool* okay) {
+    const u1* ptr = *pStream;
+    int result = readUnsignedLeb128(pStream);
+
+    if (((limit != NULL) && (*pStream > limit))
+            || (((*pStream - ptr) == 5) && (ptr[4] > 0x0f))) {
+        *okay = false;
+    }
+
+    return result;
+}
+
+/*
+ * Reads a signed LEB128 value, updating the given pointer to point
+ * just past the end of the read value and also indicating whether the
+ * value was syntactically valid. The only syntactically *invalid*
+ * values are ones that are five bytes long where the final byte has
+ * any but the low-order four bits set. Additionally, if the limit is
+ * passed as non-NULL and bytes would need to be read past the limit,
+ * then the read is considered invalid.
+ */
+int readAndVerifySignedLeb128(const u1** pStream, const u1* limit,
+        bool* okay) {
+    const u1* ptr = *pStream;
+    int result = readSignedLeb128(pStream);
+
+    if (((limit != NULL) && (*pStream > limit))
+            || (((*pStream - ptr) == 5) && (ptr[4] > 0x0f))) {
+        *okay = false;
+    }
+
+    return result;
+}