How can I execute a jar file included in c++ with a Base64 string without write it on the HDD?

Question

How I can execute a jar file included in my c++ exe file in a Base64 string without write it on the HDD? Is it possibile execute it from memory or something like this without have 2 files on the HDD?

Thanks in advance

The OS may place parts of your program on the HDD and only load them as necessary. Thus your program may be using the HDD anyway. — Thomas Matthews, Feb 13 '16 at 22:01
my idea was like launch4j but i have no idea how works it because launch4j exe has been detected as virus — , Feb 13 '16 at 22:03

Brandon · Accepted Answer · 2016-02-15T05:29:14.407

Using JNI:

Create a JVM instance.
Create a ByteArrayInputStream on the decoded base64 jar string.
Create a JarInputStream and pass it the ByteArrayInputStream.
Iterate each jarEntry in the JarInputStream and load the class with a ClassLoader.
Store each class in a HashMap for quick access.

Another way is to call JNI's:

jclass DefineClass(JNIEnv *env, const char *name, jobject loader, const jbyte *buf, jsize bufLen);

Example: https://github.com/Brandon-T/Cpp-JVM

I added the example to my Github since it was way too large to fit on StackOverflow. Note: You do not need the JNI wrapper that I wrote. It would cut down on code by a ton if you use raw JNI.

The wrapper is there from some legacy code I wrote a long time ago and I decided to just use it and have it keep track of the JavaVM and JNIEnv for me.

EDIT: Beware that I hardcoded the path to libJVM and libJNI:

https://github.com/Brandon-T/Cpp-JVM/blob/master/JVM.cpp#L41 because I couldn't get the JVM running on OSX without it.

can you write an exmple? Is the first time that i use JNI on C++, I've read some tutorials but I don't understand how do this — , Feb 14 '16 at 21:02

How can I execute a jar file included in c++ with a Base64 string without write it on the HDD?

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