Can't resolve 46 characters domains

[Petr Czepiec]

Hi,

It's not possible resolve domain if any part of DNS (label) have 46 characters, for example:

>>> DNS.dnslookup('1234567890123456789012345678901234567890123456', 'a')
Traceback (most recent call last):
  File "/usr/lib64/python3.4/encodings/idna.py", line 165, in encode
    raise UnicodeError("label empty or too long")
UnicodeError: label empty or too long

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.4/site-packages/DNS/lazy.py", line 37, in dnslookup
    result = Base.DnsRequest(name=name, qtype=qtype).req()
  File "/usr/lib/python3.4/site-packages/DNS/Base.py", line 319, in req
    m.addQuestion(qname, qtype, Class.IN)
  File "/usr/lib/python3.4/site-packages/DNS/Lib.py", line 628, in addQuestion
    self.addname(qname)
  File "/usr/lib/python3.4/site-packages/DNS/Lib.py", line 192, in addname
    buf = buf + (bytes(chr(n), enc) + label)
UnicodeError: encoding with 'idna' codec failed (UnicodeError: label empty or too long)

I think line 192 of Lib.py:
buf = buf + (bytes(chr(n), enc) + label)
is a nonsense (why is there IDNA encoding for num of chars of label?)

Thanks,
Petr Czepiec

[Petr Czepiec (petr-czepiec)]

I fixed it in branch https://code.launchpad.net/~petr-czepiec/py3dns/py3dns, file DNS/Lib.py, line 192:
buf = buf + bytes([n]) + label

please check and merge it,

Petr Czepiec

[Scott Kitterman (kitterman)]

I'm not sure why I didn't see this when it came in. Sorry for the delay. Thanks for the fix. I'll release something with this included shortly.

[Scott Kitterman (kitterman)]

Fixed in 3.1.1.