Crypto++ module is too big.

[SeungYoup Lee]

I have a problem. 

I want to only RSA module in Android ndk enviroment.

When I build Crypto++ ..(so) ..  but module size too big 

(cryptopp module, stl module, user module = 3.. too many..) 

I visits many site.. but i can't small build..

(also i sam it. .. http://morgwai.pl/ndkTutorial/ )

I want to build crypto++ static library (because reduce module size..) 

How can I start... ? 

Please help me..

Reference.. 

https://stackoverflow.com/questions/8914264/subset-of-cryptopp-library-for-mobile-usage-ios-android-ndk

If you want to use crypto++ (and there are many good reasons you'd want to) this is probably a scenario where you're just best off letting the linkers do their job. I was concerned about this some time ago, and I could not do any better by hand than the optimizing linkers could.

I confirmed this by dusting off my old test app that uses crypto++ to generate a new random RSA key, sign a string and verify that string. Here are the numbers I see:

• libcryptopp.a - crypto++ built for release as a static library using clang++ against the iOS SDK 5.0. There was no special attmept to minimize size, just built with -fvisibility=hidden -fvisibility-inlines-hidden and -Os:22.5MB

• Empty app from the default iOS single view template, built with -Os: 34KB

• The same empty app with "self test" code added that generates a keypair, signs (and therefore hashes) a string using RSA/SHA256, hex encodes it, prints the signature, decodes the signature and verifies the signature over the original string, built with -Os against the libcryptopp.a from my first bullet above: 389KB

The linker seems to be doing a good job here. If you're seeing something drastically different, make sure you're really looking at release binaries.

[Jeffrey Walton]

On Thursday, September 18, 2014 11:20:59 PM UTC-4, SeungYoup Lee wrote:

I want to only RSA module in Android ndk enviroment.

When I build Crypto++ ..(so) ..  but module size too big 

(cryptopp module, stl module, user module = 3.. too many..) 

I visits many site.. but i can't small build..

(also i sam it. .. http://morgwai.pl/ndkTutorial/ )

I want to build crypto++ static library (because reduce module size..) 

How can I start... ? 

Please help me..

I think you are doing many things you should be. The issue is the Crypto++ shared object has a lot of functionality, and you don't want or need it.

Here's how I would approach it:

1. Compile Crypto++ with -ffunction-sections -fdata-sections
2. Create a wrapped shared object, compile with -Os
3. Wrapper uses -fvisibility=hidden and -Wl,--exclude-libs,ALL
4  Wrapper links against libcryptopp.a
5. Run 'strip' after building you library

I believe strip uses --strip-unneeded. I think you can get more aggressive (like --strip-debug and --strip-all) . But the downside is your crash reports will become useless.

You should add -ffunction-sections, -fdata-sections, -fvisibility=hidden and -Wl,--exclude-libs,ALL to CFLAGS and CXXFLAGS.

There's also a page on the Crypto++ wiki covering Android at http://www.cryptopp.com/wiki/Android_%28Command_Line%29 . The wiki is still having some problems (like thumbnail images not available), but you can read it.
 

[SeungYoup Lee]

Hi ! First of all .. I very appreciate with your answer ! 

I don't expect answer .. but I saw your answer and I moved it. 

I saw your other article about crypto++ and I learned a lot of things ! 

for example.. http://www.codeproject.com/script/Membership/View.aspx?mid=349853 

CASE1 : Vmware + Ubuntu 14.0 + NDK 10r 

I saw this site. but it is very difficult for me.

http://www.cryptopp.com/wiki/Android_%28Command_Line%29

So, I download source file and I unzip cryptopp-android-14.zip 

https://github.com/noloader/cryptopp-5.6.2-android-14

After unzip file (cryptopp-android-14.zip) i get libcryptopp.a file. 

1) I create Android Application Project in Eclipse ( also I install CDT Plugin ) 

2) I create jni folder and copy cryptopp header file (in cryptopp-android-14.zip include files) 

3) I put libcryptopp.a file in libs/libcryptopp.a

4) I reference this site http://morgwai.pl/ndkTutorial/ 

and visit http://morgwai.pl/ndkTutorial/ 

5) download NdkTutorial project and copy src folder, AndroidmManifest.xml, res folder 

(if you error file in res folder just remove!, and R file error appropreate change) 

6) I create my module in jni folder named crypt_user.cpp 

extern "C" {

JNIEXPORT jstring JNICALL Java_pl_morgwai_ndktutorial_Native_fun(JNIEnv *env,

jobject) {

string readSignater;

string publicFileName = "publicKey";

string message = "RSA System Test";

try {

AutoSeededRandomPool rng;

InvertibleRSAFunction parameters;

parameters.GenerateRandomWithKeySize(rng, 1024);

RSA::PublicKey publicKey(parameters);

.... 

} // try

catch (CryptoPP::Exception& e) {

std::cerr << "Error: " << e.what() << std::endl;

}

return (env)->NewStringUTF("Hello JNI!!!!!");

}

}

7) Edit Android.mk file 

LOCAL_PATH := $(call my-dir) 

include $(CLEAR_VARS)

LOCAL_MODULE := static_crypt          # anything.. 

LOCAL_SRC_FILES := ../libs/libcryptopp.a        #  libs/libcryptopp.a (in cryptopp-android-14.zip include files) 

include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS) 

LOCAL_MODULE    := mymodule

LOCAL_C_INCLUDES := \

$(LOCAL_PATH)/cryptopp \

FILE_LIST := \

$(wildcard $(LOCAL_PATH)/*.c*) \

LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%)  

# Add ..

LOCAL_CFLAGS := -Os

LOCAL_CFLAGS += -ffunction-sections

LOCAL_CFLAGS += -fdata-sections

LOCAL_CFLAGS += -fvisibility=hidden

LOCAL_CFLAGS += -Wl

LOCAL_CFLAGS += --exclude-libs

LOCAL_STATIC_LIBRARIES := static_crypt 

include $(BUILD_SHARED_LIBRARY) 

8) Edit Application.mk 

APP_ABI := armeabi 

APP_STL := stlport_static 

APP_PLATFORM := android-8

APP_CFLAGS += -Wno-error=format-security

APP_CFLAGS += -fexceptions \

-fpermissive \

-frtti

9) build command ndk-build 

move project position 

ex)   /workspace/Staticbuild/jni

and ndk-build 

$ ndk-build

[armeabi] SharedLibrary  : libmymodule.so

[armeabi] Install        : libmymodule.so 

10) After build the module size 5KB !! 

11) For test, I Edit 

package pl.morgwai.ndktutorial;

public class Native {

public static final String LOG_TAG = Native.class.getSimpleName();

static {

System.loadLibrary("mymodule");

}

public native String fun();

}

CASE2 : window  + NDK 10r 

I download Crypto++ 5.6.2 and build in eclipse with window enviroment 

( setting :  install cygwin for window & install eclipse CDT plugin ) 

Environment

- Eclipse with CDT

- window 

- cygwin 

- NDK, SDK (android) 

First, I build raw crypto++ source code static library. 

1) Create Android Application Project in Eclipse

2) Create JNI Folder and copy Crypto++ source code all (Specific position) 

3) In Eclipse project, click right click . new -> convert c++ project ( select static library option) 

4) create Android.mk file and Application.mk file 

< Application.mk > 

APP_ABI := armeabi

APP_STL := stlport_static

APP_CFLAGS += -Wno-error=format-security

APP_CFLAGS += -fexceptions \

-fpermissive

< Android.mk > 

# sattic library build file 

include $(CLEAR_VARS)

# module name ramdom .. (you want) 

LOCAL_MODULE    := random name 

# put crptopp all file (jni/cryptopp) 

FILE_LIST := $(wildcard $(LOCAL_PATH)/cryptopp/*.c*)

LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%) 

include $(BUILD_STATIC_LIBRARY) 

# dummy so file 

include $(CLEAR_VARS)

LOCAL_MODULE    := garbage

LOCAL_STATIC_LIBRARIES :=  random name 

include $(BUILD_SHARED_LIBRARY)

5) Chaing eclipse project setting properties 

-C/C++ build : builder Settings - build command : ndk-build.cmd

-C/C++ General : Path and symbols - Include Setting position toolchain.. 

(similar : http://202psj.tistory.com/465)

6) build and get libcrypto.a ( project - obj - local - armeabi - XXX.a) 

Second, I create another project 

1) Create Android Application Project in Eclipse

2) Create Jni Folder and copyt crypto++ header file 

3) And write my code under jni folder ( reference crypto++ api ) + put libcrypto.a file 

4) Edit Android.mk, Application.mk and build so library 

LOCAL_PATH := $(call my-dir) 

include $(CLEAR_VARS)

LOCAL_MODULE := cryptopplibrary

# static build library position

LOCAL_SRC_FILES := ../libs/libcrpytopp.a        

include $(PREBUILT_STATIC_LIBRARY)

include $(CLEAR_VARS) 

LOCAL_LDLIBS := -llog -lz

LOCAL_MODULE    := temp

LOCAL_CFLAGS := -Os

LOCAL_CFLAGS += -ffunction-sections

LOCAL_CFLAGS += -fdata-sections

LOCAL_CFLAGS += -fvisibility=hidden

LOCAL_CFLAGS += -Wl

LOCAL_CFLAGS += --exclude-libs

LOCAL_C_INCLUDES := \

$(LOCAL_PATH) \

$(LOCAL_PATH)/cryptopp \

FILE_LIST := \

$(wildcard $(LOCAL_PATH)/*.c*) \

LOCAL_SRC_FILES := $(FILE_LIST:$(LOCAL_PATH)/%=%)  

LOCAL_STATIC_LIBRARIES := cryptopplibrary

include $(BUILD_SHARED_LIBRARY) 

4) After build , I create my crypto library (only i want function ) 

The size is down!! 

[Jeffrey Walton]

On Thursday, September 18, 2014 at 11:20:59 PM UTC-4, SeungYoup Lee wrote:

I have a problem. 

I want to only RSA module in Android ndk enviroment.

When I build Crypto++ ..(so) ..  but module size too big 

(cryptopp module, stl module, user module = 3.. too many..) 

I visits many site.. but i can't small build..

(also i sam it. .. http://morgwai.pl/ndkTutorial/ )

I want to build crypto++ static library (because reduce module size..) 

How can I start... ?

This is a bit late but... We added a wiki page on creating wrapper DLLs. Also see https://www.cryptopp.com/wiki/Wrapper_DLL .

Jeff