How to link crypto shared library in Android JNI

Question

I am writing a wrapper to use some functions of crypto. I build crypto lib from openssl-android with Android-NDK. Now i have the libcrypto.so that i need, but i don´t know how to link it with my wrapper.

My project tree is like this

(proj root)
|
|->(src)
|->(src)-> com.package
|->(src)-> com.package->NativeCipher.java
|
|->(jni)
|->(jni)->Android.mk
|->(jni)->NativeCipher.c

NativeCipher.java

public class NativeCipher {
    static {
         System.loadLibrary("crypto");
         System.loadLibrary("NativeCipher");
     }

     public static native byte[] AESEncrypt(byte[] in, byte[] key);
}

NativeCipher.c

#include <string.h>
#include <jni.h>
#include <aes.h>

jbyteArray Java_com_package_NativeCipher_AESEncrypt(JNIEnv* env, jobject this, jbyteArray in, jbyteArray key)
{
    // All my code here
}

I need to use the functions of #include that crypto provides. However, i don't know what to do with the .so files that NDK generates and how to make the Android.mk file to build.

Thanks in advance, i tried to be as specific as posible.

Answer 1

Native libraries go to the libs/armeabi or libs/armeabi-v7a of your Android project. You might want to rename the OpenSSL library though, because the system already has a libcrypto.so . As for your own JNI wrapper, just take the shared library sample from the NDK and modify to use your own files.