I have a compiled binary of Dropbear. When I do file dbclient I get the following :
dbclient: ELF 32-bit LSB executable, ARM, version 1 (SYSV),
dynamically linked (uses shared libs), stripped
When I am trying to compile it on my own (very beginner) with
./configure --host=arm-linux-gnueabi --prefix=/ --disable-zlib
CC=arm-linux-gnueabi-gcc LD=arm-linux-gnueabi-ld make make install
I get the following after it compiled
dbclient: ELF 32-bit LSB executable, ARM, version 1 (SYSV),
dynamically linked (uses shared libs), for GNU/Linux 2.6.31,
BuildID[sha1]=0x016ac7e729afb02d60248393619b41380379777d, not stripped
For the stripped part, I don't care I could strip it later.
But my question is how to specify the "for GNU/Linux 2.6.31". What does it mean and how do I change it to target Linux 3.10.49 armv5tejl?
Related
I directly use the binary file you released to test on my arm64-based computer. But the test result is not normal operation. The reason is that nw interpreter needs to be /lib/ld-linux-aarch64.so.1 instead of /lib/ld-linux-armhf.so.3 on Linux version 4.19.172 for arm64.
How to compile the binary file so that the interpreter of this file is /lib/ld-linux-aarch64.so?
$ file ./nwjs-chromium-ffmpeg-branding/nwjs-v0.52.3-linux-arm/nw
$ ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 3.2.0, BuildID[xxHash]=4c8a98c5d541ac00, stripped
But, I want to get a binary executable file like this：
$ file ./nwjs-chromium-ffmpeg-branding/nwjs-v0.52.3-linux-arm/nw
$ ELF 32-bit LSB shared object, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-aarch64.so.1, for GNU/Linux 3.2.0, BuildID[xxHash]=4c8a98c5d541ac00, stripped
I'm trying to generate ARM Object file under ubuntu using arm-none-eabi package but without success.
url describing this format:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0041c/BCEJDJBC.html
root#ubuntu:~/arm/blink# arm-none-eabi-as hello.S
root#ubuntu:~/arm/blink# file a.out
a.out: ELF 32-bit LSB relocatable, ARM, version 1 (SYSV), not stripped
OpenSSL doesn't work well with valgrind unless you build it with a particular option so I've build OpenSSL again so that I can debug a program easily. The problem is, every time I build the program it links to an OpenSSL library I do not want. My makefile prints out a lot but the two lines that are most important are:
cc /usr/local/ssl/lib/libcrypto.so.1.0.0 /usr/local/ssl/lib/libssl.so.1.0.0 -L/opt/local/lib -shared -o bin/libcbitcoin-crypto.2.0.so build/CBOpenSSLCrypto.o
cc build/testCBNodeFull.o -L/home/matt/Desktop/cbitcoin/bin -lcbitcoin.2.0 -lcbitcoin-network.2.0 -lcbitcoin-storage.2.0 -lcbitcoin-threads.2.0 -lcbitcoin-logging.2.0 -lcbitcoin-crypto.2.0 -lcbitcoin.2.0 -lcbitcoin-file-ec.2.0 -lcbitcoin-rand.2.0 -L/opt/local/lib -lpthread -levent_core -levent_pthreads /usr/local/ssl/lib/libcrypto.so.1.0.0 -o bin/testCBNodeFull
As suggested elsewhere I'm specifying the precise location of the OpenSSL library I want. However ldd bin/testCBNodeFull gives me this:
libcrypto.so.1.0.0 => /lib/x86_64-linux-gnu/libcrypto.so.1.0.0
There is apparently nothing wrong with the library I want to link to:
$ file bin/testCBNodeFull
bin/testCBNodeFull: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0xd9472ecc11e12dc66d165c807a5dbe31fd461cf2, not stripped
$ file /usr/local/ssl/lib/libcrypto.so.1.0.0
/usr/local/ssl/lib/libcrypto.so.1.0.0: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, BuildID[sha1]=0xb75602dc478ae55576e21aac5251b915b1653e73, not stripped
Both compiled as x86-64 as you can see. Maybe there is a tool that allows me to change the location of the shared library of the executable?
Shared libraries are loaded at runtime, not compile time. So, you need to tell valgrind which OpenSSL library you want it to use at runtime. You can do this by setting the LD_LIBRARY_PATH environment variable to the directory containing your rebuilt object.
export LD_LIBRARY_PATH=/home/matt/mylib
#now try ldd bin/testCBNodeFull
I have a ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), which is also stripped, and I want to explore it. Does anyone know how to decompile such a file?
IDA plus Hex-Rays decompiler can decompile (to pseudo-C code) most of 32-bit x86 code, including Linux ELF files.
Disclaimer: I work for Hex-Rays.
Is there a way to know what shared libraries are used from a executable file ?
From DivFix++ for example:
$ file DivFix++
DivFix++: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.15, stripped
Using ldd:
$ ldd DivFix++
You can use the ldd command which prints the shared library dependencies:
ldd DivFix++