Add aarch64 documentation, which enables doctests (#875)

* Add aarch64 documentation, which enables doctests

* Fix failing doctest

* Attempt to figure out whats going on with Travis

* Use the Xenial version of qemu-static since the Zesty version is broken for AArch64

docs/source/shellcraft/aarch64.rst

@@ -0,0 +1,19 @@
+.. testsetup:: *
+
+   from pwn import *
+   context.clear(arch='aarch64')
+
+:mod:`pwnlib.shellcraft.aarch64` --- Shellcode for AArch64
+===========================================================
+
+:mod:`pwnlib.shellcraft.aarch64`
+-----------------------------
+
+.. automodule:: pwnlib.shellcraft.aarch64
+   :members:
+
+:mod:`pwnlib.shellcraft.aarch64.linux`
+-----------------------------------
+
+.. automodule:: pwnlib.shellcraft.aarch64.linux
+   :members:

pwnlib/shellcraft/templates/aarch64/linux/cat.asm

@@ -9,7 +9,28 @@ Opens a file and writes its contents to the specified file descriptor.
 Example:
 
     >>> write('flag', 'This is the flag\n')
-    >>> run_assembly(shellcraft.cat('flag')).recvline()
+    >>> shellcode = shellcraft.cat('flag') + shellcraft.exit(0)
+    >>> print disasm(asm(shellcode))
+       0:   d10043ff        sub     sp, sp, #0x10
+       4:   d28d8cc0        mov     x0, #0x6c66                     // #27750
+       8:   f2acec20        movk    x0, #0x6761, lsl #16
+       c:   f80003e0        stur    x0, [sp]
+      10:   910003e0        mov     x0, sp
+      14:   aa1f03e1        mov     x1, xzr
+      18:   aa1f03e2        mov     x2, xzr
+      1c:   d2808008        mov     x8, #0x400                      // #1024
+      20:   d4000001        svc     #0x0
+      24:   aa0003e1        mov     x1, x0
+      28:   d2800020        mov     x0, #0x1                        // #1
+      2c:   aa1f03e2        mov     x2, xzr
+      30:   d29fffe3        mov     x3, #0xffff                     // #65535
+      34:   f2afffe3        movk    x3, #0x7fff, lsl #16
+      38:   d28008e8        mov     x8, #0x47                       // #71
+      3c:   d4000001        svc     #0x0
+      40:   aa1f03e0        mov     x0, xzr
+      44:   d2800ba8        mov     x8, #0x5d                       // #93
+      48:   d4000001        svc     #0x0
+    >>> run_assembly(shellcode).recvline()
     'This is the flag\n'
 </%docstring>
 

travis/install.sh

@@ -10,7 +10,7 @@ local_deb_extract()
 
 install_deb()
 {
-    version=zesty
+    version=${2:-zesty}
     package=$1
     echo "Installing $package"
     INDEX="http://packages.ubuntu.com/en/$version/amd64/$package/download"
@@ -28,7 +28,7 @@ setup_travis()
     [[ -f usr/bin/objcopy ]] || install_deb binutils
 
     # Install/upgrade qemu
-    [[ -f usr/bin/qemu-arm-static ]] || install_deb qemu-user-static
+    [[ -f usr/bin/qemu-arm-static ]] || install_deb qemu-user-static xenial
 
     # Install cross-binutils
     [[ -f usr/bin/x86_64-linux-gnu-ar ]]    || install_deb binutils-multiarch