[Aboriginal] Using native-build.sh for An Android native C compiler

[Earlence Fernandes]

note that I modify PATH and LD_LIBRARY_PATH to _include_ the bin/ and lib/
of the native compiler.
otherwise, the executable does not run.
and I specify an absolute path in dlopen, so I dont see how it can get
confused.

-Earlence

On Sat, Jul 16, 2011 at 9:05 PM, Earlence Fernandes <earlenceferns at gmail.com
> wrote:

> >Have you tried to dlopen() one of the other shared libraries that comes
> >with uClibc just to make sure that the issue is dlopen() and not it
> >being really confused by that particular library?
>
> I tried it with libm.a shipped with my native compiler. It worked ok!!
>
> strange that is doesn't open /system/lib/libc.so
> Thoughts?
>
> -Earlence
>
>
> On Sat, Jul 16, 2011 at 8:49 PM, Earlence Fernandes <
> earlenceferns at gmail.com> wrote:
>
>> Yes, it is bionic's libc.
>> This is what readelf says about the header:
>> $ readelf -h /system/lib/libc.so
>> ELF Header:
>>   Magic:   7f 45 4c 46 01 01 01 00 00 00 00 00 00 00 00 00
>>   Class:                             ELF32
>>   Data:                              2's complement, little endian
>>   Version:                           1 (current)
>>   OS/ABI:                            UNIX - System V
>>   ABI Version:                       0
>>   Type:                              DYN (Shared object file)
>>   Machine:                           ARM
>>   Version:                           0x1
>>   Entry point address:               0x0
>>   Start of program headers:          52 (bytes into file)
>>   Start of section headers:          273024 (bytes into file)
>>   Flags:                             0x5000000, Version5 EABI
>>   Size of this header:               52 (bytes)
>>   Size of program headers:           32 (bytes)
>>   Number of program headers:         6
>>   Size of section headers:           40 (bytes)
>>   Number of section headers:         22
>>   Section header string table index: 21
>>
>> therefore, We can conclude
>> 1. its a proper library for ARM EABI
>> 2. its no an issue specific to my build (bcoz of the simple program I
>> wrote to read this libc.so and the result of running it with multiple
>> builds).
>> 3. its a ucLibC thing.
>>
>> What I'm trying to do is basically compile and execute one of the root
>> exploits directly on the device. No! I'm not a malware writer, but we are
>> security researchers (http://few.vu.nl/~earlence)
>>
>> http://pastebin.com/JTUbLjcz
>> That is the GingerBreak exploit that I'm trying to compile.
>>
>> -Earlence
>>
>>
>> On Sat, Jul 16, 2011 at 8:18 PM, Rob Landley <rob at landley.net> wrote:
>>
>>> On 07/16/2011 12:59 PM, Earlence Fernandes wrote:
>>> > Thank you for the reply.
>>> >
>>> > 1. gb is custom software (sorry I should have made a note of that).
>>> > 2. I rewrote a simple program with one line
>>> >
>>> > void *dlh = dlopen("/system/lib/libc.so", RTLD_NOW);
>>>
>>> Um, question: is that bionic's libc you're attempting to dlopen?  (It's
>>> an ELF binary, right?  What does readelf -a say about it?  Note that
>>> attemting to dlopen() a linker script may not end well.)
>>>
>>> Have you tried to dlopen() one of the other shared libraries that comes
>>> with uClibc just to make sure that the issue is dlopen() and not it
>>> being really confused by that particular library?
>>>
>>> > I tried it on my build - same problem. seg fault.
>>> > I tried it with the build you sent me, same problem - seg faults again.
>>> >
>>> > Is it possible to write a program precompiled with Android's dynamic
>>> > linker that will bootstrap the uclibc version? (I know going off topic
>>> > here).
>>>
>>> I don't understand what you're trying to do there, could you explain?
>>> (You can exec one program from another, if that's what you mean by
>>> boostrap.)
>>>
>>> > Or would it be possible to link the program against android ldl.a in
>>> the
>>> > first place?
>>>
>>> I expect it's possible to link it, whether the result would work
>>> involves knowing more about android than I do.
>>>
>>> > -Earlence
>>>
>>> Rob
>>>
>>
>>
>
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