add 'AMD64' arch in get_system_arch()

[pingport80]

Summary

This PR appends a condition in the method get_system_arch() which returns the value of platform.uname()[4] when ctypes module is not present. The value can be x86_64 and AMD64 based on the processor type. But for consistency it should return x64 in both the cases.

Before

if arch == 'x86_64`:
    return arch

After

if arch == `x86_64` or arch == `AMD64`:
    return arch

[cdelafuente-r7]

Do you think this should be a case insensitive test instead? I'm not sure about the exact output of platform.uname().

[timwr]

I think it's worth calling arch.lower() see https://github.com/rapid7/metasploit-payloads/pull/530/files and https://github.com/rapid7/metasploit-framework/blob/master/lib/msf/core/post/linux/kernel.rb

[pingport80]

okay, I'll update it, thanks!

[adfoster-r7]

Mac:

>>> import platform
>>> platform.uname()[4]
'x86_64'

Linux:

>>> import platform
>>> platform.uname()[4]
'x86_64'

Windows vm with python 3.1.1 installed via choco

>>> import platform
>>> platform.uname()[4]
'AMD64'
>>>

Potentially relevant issue was raised on Python itself platform.uname()[4] returns 'amd64' on Windows and 'x86-64' on Linux:

Cygwin on Windows uses "x86_64", FreeBSD uses "amd64", Linux uses "x86_64". Mac OS X uses "x86_64" for Intels (and ppc64" for PowerPCs).

[adfoster-r7]

#555 (comment)

In particular:

Cygwin on Windows uses "x86_64", FreeBSD uses "amd64", Linux uses "x86_64". Mac OS X uses "x86_64" for Intels (and ppc64" for PowerPCs).

Should we add those values too? 👀

[adfoster-r7]

It looks like the edgecases are only really around powerpc, which isn't a super relevant target these days

From the freebsd uname man pages:

EXAMPLES
     The hardware platform (-m)	can be different from the machine's processor
     architecture (-p),	e.g., on 64-bit	PowerPC, -m would return powerpc and
     -p	would return powerpc64