diff --git a/applypatch/Android.mk b/applypatch/Android.mk
index 49f9989..bc2e69e 100644
--- a/applypatch/Android.mk
+++ b/applypatch/Android.mk
@@ -20,7 +20,7 @@
 LOCAL_SRC_FILES := applypatch.cpp bspatch.cpp freecache.cpp imgpatch.cpp utils.cpp
 LOCAL_MODULE := libapplypatch
 LOCAL_MODULE_TAGS := eng
-LOCAL_C_INCLUDES += external/bzip2 external/zlib bootable/recovery
+LOCAL_C_INCLUDES += bootable/recovery
 LOCAL_STATIC_LIBRARIES += libbase libotafault libmtdutils libmincrypt libbz libz
 
 include $(BUILD_STATIC_LIBRARY)
@@ -28,6 +28,30 @@
 include $(CLEAR_VARS)
 
 LOCAL_CLANG := true
+LOCAL_SRC_FILES := bspatch.cpp imgpatch.cpp utils.cpp
+LOCAL_MODULE := libimgpatch
+LOCAL_C_INCLUDES += bootable/recovery
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_STATIC_LIBRARIES += libmincrypt libbz libz
+
+include $(BUILD_STATIC_LIBRARY)
+
+ifeq ($(HOST_OS),linux)
+include $(CLEAR_VARS)
+
+LOCAL_CLANG := true
+LOCAL_SRC_FILES := bspatch.cpp imgpatch.cpp utils.cpp
+LOCAL_MODULE := libimgpatch
+LOCAL_C_INCLUDES += bootable/recovery
+LOCAL_EXPORT_C_INCLUDE_DIRS := $(LOCAL_PATH)/include
+LOCAL_STATIC_LIBRARIES += libmincrypt libbz libz
+
+include $(BUILD_HOST_STATIC_LIBRARY)
+endif  # HOST_OS == linux
+
+include $(CLEAR_VARS)
+
+LOCAL_CLANG := true
 LOCAL_SRC_FILES := main.cpp
 LOCAL_MODULE := applypatch
 LOCAL_C_INCLUDES += bootable/recovery
diff --git a/applypatch/bspatch.cpp b/applypatch/bspatch.cpp
index 9d201b4..75975ad 100644
--- a/applypatch/bspatch.cpp
+++ b/applypatch/bspatch.cpp
@@ -22,6 +22,7 @@
 
 #include <stdio.h>
 #include <sys/stat.h>
+#include <sys/types.h>
 #include <errno.h>
 #include <malloc.h>
 #include <unistd.h>
diff --git a/applypatch/imgpatch.cpp b/applypatch/imgpatch.cpp
index 26888f8..3e72b2c 100644
--- a/applypatch/imgpatch.cpp
+++ b/applypatch/imgpatch.cpp
@@ -31,13 +31,22 @@
 #include "imgdiff.h"
 #include "utils.h"
 
+int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
+                    const unsigned char* patch_data, ssize_t patch_size,
+                    SinkFn sink, void* token) {
+  Value patch = {VAL_BLOB, patch_size,
+      reinterpret_cast<char*>(const_cast<unsigned char*>(patch_data))};
+  return ApplyImagePatch(
+      old_data, old_size, &patch, sink, token, nullptr, nullptr);
+}
+
 /*
  * Apply the patch given in 'patch_filename' to the source data given
  * by (old_data, old_size).  Write the patched output to the 'output'
  * file, and update the SHA context with the output data as well.
  * Return 0 on success.
  */
-int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size __unused,
+int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
                     const Value* patch,
                     SinkFn sink, void* token, SHA_CTX* ctx,
                     const Value* bonus_data) {
@@ -80,6 +89,10 @@
             size_t src_len = Read8(normal_header+8);
             size_t patch_offset = Read8(normal_header+16);
 
+            if (src_start + src_len > static_cast<size_t>(old_size)) {
+                printf("source data too short\n");
+                return -1;
+            }
             ApplyBSDiffPatch(old_data + src_start, src_len,
                              patch, patch_offset, sink, token, ctx);
         } else if (type == CHUNK_RAW) {
@@ -123,6 +136,11 @@
             int memLevel = Read4(deflate_header+52);
             int strategy = Read4(deflate_header+56);
 
+            if (src_start + src_len > static_cast<size_t>(old_size)) {
+                printf("source data too short\n");
+                return -1;
+            }
+
             // Decompress the source data; the chunk header tells us exactly
             // how big we expect it to be when decompressed.
 
diff --git a/applypatch/include/applypatch/imgpatch.h b/applypatch/include/applypatch/imgpatch.h
new file mode 100644
index 0000000..64d9aa9
--- /dev/null
+++ b/applypatch/include/applypatch/imgpatch.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef _IMGPATCH_H
+#define _IMGPATCH_H
+
+typedef ssize_t (*SinkFn)(const unsigned char*, ssize_t, void*);
+
+int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
+                    const unsigned char* patch_data, ssize_t patch_size,
+                    SinkFn sink, void* token);
+
+#endif  //_IMGPATCH_H