[Python 2 to 3] Bytes fixes

[gpotter2]

Here's the most boring part of it. That should bring neally all bytes support for the core. Contribution files will be changed later.

This PR:

• introduces some util functions in scapy.compat.py that works on both python 2 and 3:
  -- raw(x) : returns the byte form of a string/packet/int/list of ints
  -- plain_str(x) : does exactly the opposite: bytes/int ==> str
  -- hex_bytes / bytes_hex ==> converts hex => bytes or bytes => hex
• Remove stupid BGP bug in a test: None ==> "None" ==> "\x04". Fixed by using raw

[codecov-io]

Codecov Report

Merging #674 into master will increase coverage by 0.01%.
The diff coverage is 80.81%.

@@            Coverage Diff             @@
##           master     #674      +/-   ##
==========================================
+ Coverage   80.69%   80.71%   +0.01%     
==========================================
  Files         137      137              
  Lines       33903    34005     +102     
==========================================
+ Hits        27357    27446      +89     
- Misses       6546     6559      +13

Impacted Files	Coverage Δ
scapy/layers/all.py	83.33% <0%> (-4.91%)	⬇️
scapy/asn1/mib.py	78.47% <100%> (+0.15%)	⬆️
scapy/layers/vrrp.py	84.09% <100%> (+0.36%)	⬆️
scapy/arch/common.py	100% <100%> (ø)	⬆️
scapy/layers/tls/crypto/h_mac.py	92.06% <100%> (+0.12%)	⬆️
scapy/pton_ntop.py	97.26% <100%> (+0.2%)	⬆️
scapy/layers/tls/crypto/pkcs1.py	73.48% <100%> (+0.2%)	⬆️
scapy/dadict.py	98.71% <100%> (+0.01%)	⬆️
scapy/modules/nmap.py	97.01% <100%> (+0.04%)	⬆️
scapy/arch/__init__.py	90% <100%> (ø)	⬆️
... and 40 more

[gpotter2]

@p-l- @guedou Calling for review.

[gpotter2]

Ok I'm now able to boot scapy using python 3 (windows and ubuntu)... Tons of stuff must be broken though...

[gpotter2]

Rebased (apply mtury's work).

[gpotter2]

Status update:

• Squashed and rebased
• Removed many raw() unneeded
• Some raw() are important: when raw bytes want to be converted from str to bytes, it's required to use raw() (non-ascii str)

[guedou]

@gpotter2 don't forget to update the title when it its ready to be reviewed =)

[gpotter2]

@guedou @p-l- Ready to be reviewed

[gpotter2]

I've added python 3 launchers

[guedou]

Is this really needed ?

[gpotter2]

No, nice catch

[guedou]

Is the new indentation needed ?

[gpotter2]

Yes, the change log is a bit messy but the code is

if six.PY2:
    def crc32(x):
        return "%08X" % (0xffffffff & zlib.crc32(x))

    def sha1(x):
         return hashlib.sha1(x).hexdigest().upper()
else:
    def crc32(x):
        return "%08X" % (0xffffffff & zlib.crc32(bytearray(x, "utf8")))

    def sha1(x):
        return hashlib.sha1(x.encode("utf8")).hexdigest().upper()

[guedou]

It looks good to me !