Python – convert the key in MIME encoded form in python

encodingpython

I need to convert the key in MIME encoded form which is presently comes in (ascii armored) radix 64 format. For that, I have to get this radix64 format in its binary form and also need to remove its header and checksum than coversion in MIME format, but I didnt find any method which can do this conversion.

f = urllib.urlopen('http://pool.sks-keyservers.net:11371/pks/lookup?op=get&search= 0x58e9390daf8c5bf3') #Retrieve the public key from PKS

data = f.read()
decoded_bytes = base64.b64decode(data)
print decoded_bytes

I used the base64.b64decode method and it gives me the following error:

Traceback (most recent call last):
  File "RetEnc.py", line 12, in ?
    decoded_bytes = base64.b64decode(data)
  File "/usr/lib/python2.4/base64.py", line 76, in b64decode
    raise TypeError(msg)
TypeError: Incorrect padding

Why am I get this TypeError: Incorrect padding error, and how cn I fix it?

Best Solution

For a start, when you do use a valid search value ("jay" returns an error stating "too many values"), you will receive an HTML page from which you need to extract the actual key. Trying a search value of "jaysh" I get the following response:

>>> print urllib.urlopen('http://pool.sks-keyservers.net:11371/pks/lookup?op=get&search=jaysh').read()
<html><head><title>Public Key Server -- Get ``jaysh ''</title></head>
<body><h1>Public Key Server -- Get ``jaysh ''</h1>
<pre>
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: SKS 1.1.1
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=tvYU
-----END PGP PUBLIC KEY BLOCK-----
</pre>
</body></html>

So you need to look only at the key which is wrapped by the <pre> HTML tags.

By the way, there are other issues that you will need to contend with such as multiple keys being returned because you are searching by "name", when you should be searching by keyID. For example, keyID 0x58E9390DAF8C5BF3 will return the public key for jaysh and only jaysh and the corresponsing URL is http://pool.sks-keyservers.net:11371/pks/lookup?op=get&search=0x58E9390DAF8C5BF3.

This was mostly covered in my earlier answer to this question which I presume you also asked.

Related Solutions

Python – What’s the canonical way to check for type in Python

To check if o is an instance of str or any subclass of str, use isinstance (this would be the "canonical" way):

if isinstance(o, str):

To check if the type of o is exactly str (exclude subclasses):

if type(o) is str:

The following also works, and can be useful in some cases:

if issubclass(type(o), str):

See Built-in Functions in the Python Library Reference for relevant information.

One more note: in this case, if you're using Python 2, you may actually want to use:

if isinstance(o, basestring):

because this will also catch Unicode strings (unicode is not a subclass of str; both str and unicode are subclasses of basestring). Note that basestring no longer exists in Python 3, where there's a strict separation of strings (str) and binary data (bytes).

Alternatively, isinstance accepts a tuple of classes. This will return True if o is an instance of any subclass of any of (str, unicode):

if isinstance(o, (str, unicode)):

Python – Convert hex string to int in Python

Without the 0x prefix, you need to specify the base explicitly, otherwise there's no way to tell:

x = int("deadbeef", 16)

With the 0x prefix, Python can distinguish hex and decimal automatically.

>>> print(int("0xdeadbeef", 0))
3735928559
>>> print(int("10", 0))
10

(You must specify 0 as the base in order to invoke this prefix-guessing behavior; if you omit the second parameter int() will assume base-10.)

Best Solution

Related Solutions

Python – What’s the canonical way to check for type in Python

Python – Convert hex string to int in Python

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