Provide helpful debug when Unicorn is not installed

[ebursztein]

Currently the leak mapping code don't work when unicorn is not installed but don't crash and as a result silently fail

[Emulating target]
Starting emulation
Traceback (most recent call last):
  File "_ctypes/callbacks.c", line 234, in 'calling callback function'
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/unicorn-1.0.2rc4-py3.6.egg/unicorn/unicorn.py", line 479, in _hookcode_cb
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/devices/rainbow/generics/cortexm.py", line 109, in block_handler
    self.base_block_handler(address)
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/devices/rainbow/rainbow.py", line 414, in base_block_handler
    r = self.stubbed_functions[f](self)
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/chipwhisperer_leakage_automaton.py", line 194, in trigger_high
    self.trigger_hook = e.emu.hook_add(uc.UC_HOOK_MEM_WRITE,
NameError: name 'uc' is not defined
Traceback (most recent call last):
  File "_ctypes/callbacks.c", line 234, in 'calling callback function'
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/unicorn-1.0.2rc4-py3.6.egg/unicorn/unicorn.py", line 479, in _hookcode_cb
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/devices/rainbow/generics/cortexm.py", line 109, in block_handler
    self.base_block_handler(address)
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/devices/rainbow/rainbow.py", line 414, in base_block_handler
    r = self.stubbed_functions[f](self)
  File "/Users/elieb/git/scaaml/scaaml/scald/tracer/chipwhisperer_leakage_automaton.py", line 205, in trigger_low
    e.emu.hook_del(self.trigger_hook)
  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/unicorn-1.0.2rc4-py3.6.egg/unicorn/unicorn.py", line 592, in hook_del
TypeError: an integer is required (got type NoneType)
Encryption: FAIL
KEY=2b7e151628aed2a6abf7158809cf4f3c
 PT=6bc1bee22e409f96e93d7e117393172a
EXP=3ad77bb40d7a3660a89ecaf32466ef97

[jmichelp]

When I manually uninstalled unicorn and launched the tool, I got a completely different message than yours:

python3 emulate_target.py -c config/stm32f415_tinyaes_sync.json
scaaml/scald/tracer/devices/rainbow/rainbow.py:356: SyntaxWarning: "is" with a literal. Did you mean "=="?
if s is '':
Traceback (most recent call last):
File "emulate_target.py", line 18, in <module>
from scaaml.scald.tracer import ChipwhispererLeakageAutomaton
File "scaaml/scald/tracer/__init__.py", line 1, in <module>
from .chipwhisperer_leakage_automaton import ChipwhispererLeakageAutomaton  # noqa
File "scaaml/scald/tracer/chipwhisperer_leakage_automaton.py", line 4, in <module>
from .devices import Stm32f415
File "scaaml/scald/tracer/devices/__init__.py", line 17, in <module>
from .stm32 import Stm32fxxx  # noqa
File "scaaml/scald/tracer/devices/stm32.py", line 20, in <module>
from .cortex_m4 import CortexM4
File "scaaml/scald/tracer/devices/cortex_m4.py", line 2, in <module>
from .rainbow.generics import rainbow_cortexm
File "scaaml/scald/tracer/devices/rainbow/__init__.py", line 19, in <module>
from .rainbow import rainbowBase  # noqa
File "scaaml/scald/tracer/devices/rainbow/rainbow.py", line 22, in <module>
import unicorn as uc
ModuleNotFoundError: No module named 'unicorn'

And the execution stopped there.

According to your output, unicorn is installed but something's wrong with it.
File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/unicorn-1.0.2rc4-py3.6.egg/unicorn/unicorn.py", line 479, in _hookcod tells me that it is installed.

[jmichelp]

The problem came from commit ae12d7d which remove the following line:

import unicorn as uc