<div dir="ltr"><div><br></div><div>Hello,</div><div><br></div><div>It's not clear for me the task 5 from the GDB section.</div><div><br></div><div>1. What means to print the stack ? We have to examine the memory between the ebp and esp pointers of the current frame stack ?</div><div>2. What registers must be printed ? The values of eax, ebx ..., or the registers saved on stack ?</div><div>3. Which is the third frame ? I see that the compute_hash is called from main. This means that the ebp from the compute_hash frame stack will point to the ebp from the main frame stack and in this case will be 0.</div><div><br></div><div>Thanks, Alex</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Nov 11, 2014 at 11:42 AM, Lucian Mogosanu <span dir="ltr"><<a href="mailto:lucian.mogosanu@gmail.com" target="_blank">lucian.mogosanu@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On Tue, Nov 11, 2014 at 08:57:02AM +0000, Razvan Nitu wrote:<br>
> Hello all,<br>
><br>
> When I tried to run the hasher binary I got this error [1]. I recompiled, but<br>
> i received [2]. I figured it might be the fact that I don't have the 32-bit<br>
> library so I compiled everything without the -m32 flag and everything worked<br>
> fine. I think that this might cause some issues if the script contains<br>
> breakpoints at hardcoded addresses. This leads me to my second question: can<br>
> we assume that ASLR is disabled ?<br>
><br>
> Razvan<br>
><br>
><br>
> [1] ./hasher: error while loading shared libraries: libcrypto.so.1.0.0:<br>
> cannot open shared object file: No such file or directory<br>
><br>
> [2] In file included from /usr/include/openssl/sha.h:63:0,<br>
> from hasher.c:1:<br>
> /usr/include/openssl/e_os2.h:56:33: fatal error: openssl/opensslconf.h: No<br>
> such file or directory<br>
> #include <openssl/opensslconf.h><br>
<br>
</span>The files you are looking for are in the libssl1.0.0 and libssl-dev libraries:<br>
<br>
spyked@tuvok:~% apt-file search opensslconf.h<br>
libcyassl-dev: /usr/include/cyassl/openssl/opensslconf.h<br>
libssl-dev: /usr/include/x86_64-linux-gnu/openssl/opensslconf.h<br>
<br>
(obviously you need libssl-dev:i386 if you are going to compile with m32)<br>
<br>
spyked@tuvok:~% apt-file search libcrypto.so.1.0.0<br>
libssl1.0.0: /usr/lib/x86_64-linux-gnu/libcrypto.so.1.0.0<br>
<br>
(same here, you need libssl1.0.0:i386)<br>
<br>
Lucian<br>
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