99 lines
3.6 KiB
Python
99 lines
3.6 KiB
Python
# Author: Trevor Perrin
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# See the LICENSE file for legal information regarding use of this file.
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from .compat import *
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import binascii
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#This code is shared with tackpy (somewhat), so I'd rather make minimal
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#changes, and preserve the use of a2b_base64 throughout.
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def dePem(s, name):
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"""Decode a PEM string into a bytearray of its payload.
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The input must contain an appropriate PEM prefix and postfix
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based on the input name string, e.g. for name="CERTIFICATE"::
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-----BEGIN CERTIFICATE-----
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MIIBXDCCAUSgAwIBAgIBADANBgkqhkiG9w0BAQUFADAPMQ0wCwYDVQQDEwRUQUNL
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...
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KoZIhvcNAQEFBQADAwA5kw==
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-----END CERTIFICATE-----
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The first such PEM block in the input will be found, and its
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payload will be base64 decoded and returned.
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"""
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prefix = "-----BEGIN %s-----" % name
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postfix = "-----END %s-----" % name
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start = s.find(prefix)
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if start == -1:
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raise SyntaxError("Missing PEM prefix")
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end = s.find(postfix, start+len(prefix))
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if end == -1:
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raise SyntaxError("Missing PEM postfix")
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s = s[start+len("-----BEGIN %s-----" % name) : end]
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retBytes = a2b_base64(s) # May raise SyntaxError
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return retBytes
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def dePemList(s, name):
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"""Decode a sequence of PEM blocks into a list of bytearrays.
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The input must contain any number of PEM blocks, each with the appropriate
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PEM prefix and postfix based on the input name string, e.g. for
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name="TACK BREAK SIG". Arbitrary text can appear between and before and
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after the PEM blocks. For example::
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Created by TACK.py 0.9.3 Created at 2012-02-01T00:30:10Z
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-----BEGIN TACK BREAK SIG-----
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ATKhrz5C6JHJW8BF5fLVrnQss6JnWVyEaC0p89LNhKPswvcC9/s6+vWLd9snYTUv
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YMEBdw69PUP8JB4AdqA3K6Ap0Fgd9SSTOECeAKOUAym8zcYaXUwpk0+WuPYa7Zmm
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SkbOlK4ywqt+amhWbg9txSGUwFO5tWUHT3QrnRlE/e3PeNFXLx5Bckg=
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-----END TACK BREAK SIG-----
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Created by TACK.py 0.9.3 Created at 2012-02-01T00:30:11Z
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-----BEGIN TACK BREAK SIG-----
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ATKhrz5C6JHJW8BF5fLVrnQss6JnWVyEaC0p89LNhKPswvcC9/s6+vWLd9snYTUv
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YMEBdw69PUP8JB4AdqA3K6BVCWfcjN36lx6JwxmZQncS6sww7DecFO/qjSePCxwM
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+kdDqX/9/183nmjx6bf0ewhPXkA0nVXsDYZaydN8rJU1GaMlnjcIYxY=
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-----END TACK BREAK SIG-----
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All such PEM blocks will be found, decoded, and return in an ordered list
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of bytearrays, which may have zero elements if not PEM blocks are found.
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"""
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bList = []
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prefix = "-----BEGIN %s-----" % name
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postfix = "-----END %s-----" % name
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while 1:
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start = s.find(prefix)
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if start == -1:
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return bList
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end = s.find(postfix, start+len(prefix))
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if end == -1:
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raise SyntaxError("Missing PEM postfix")
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s2 = s[start+len(prefix) : end]
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retBytes = a2b_base64(s2) # May raise SyntaxError
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bList.append(retBytes)
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s = s[end+len(postfix) : ]
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def pem(b, name):
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"""Encode a payload bytearray into a PEM string.
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The input will be base64 encoded, then wrapped in a PEM prefix/postfix
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based on the name string, e.g. for name="CERTIFICATE"::
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-----BEGIN CERTIFICATE-----
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MIIBXDCCAUSgAwIBAgIBADANBgkqhkiG9w0BAQUFADAPMQ0wCwYDVQQDEwRUQUNL
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...
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KoZIhvcNAQEFBQADAwA5kw==
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-----END CERTIFICATE-----
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"""
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s1 = b2a_base64(b)[:-1] # remove terminating \n
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s2 = ""
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while s1:
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s2 += s1[:64] + "\n"
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s1 = s1[64:]
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s = ("-----BEGIN %s-----\n" % name) + s2 + \
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("-----END %s-----\n" % name)
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return s
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def pemSniff(inStr, name):
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searchStr = "-----BEGIN %s-----" % name
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return searchStr in inStr
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