pyasn1: IndexError: tuple index out of range when encoding X509 Cert

I think this one was not reported yet 😃

I used pyasn1 to extract the X509 certificate part of an PKCS#7 Message, here is an example:

import binascii
from pyasn1.codec.der.decoder import decode
from pyasn1.codec.der.encoder import encode

certhex  = b"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"

pkcs7message = binascii.unhexlify(certhex)

message, _ = decode(pkcs7message)
cert = encode(message[1][3])
print(cert)

With version 0.3.3 this fails due to the following error, it worked fine with the versions before 0.3.1:

Traceback (most recent call last):
  File "bla.py", line 12, in <module>
    cert = encode(message[1][3])
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\codec\der\encoder.py", line 56, in __call__
    return encoder.Encoder.__call__(self, value, defMode, maxChunkSize, ifNotEmpty=ifNotEmpty)
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\codec\cer\encoder.py", line 208, in __call__
    return encoder.Encoder.__call__(self, value, defMode, maxChunkSize, ifNotEmpty)
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\codec\ber\encoder.py", line 483, in __call__
    self, value, defMode, maxChunkSize, ifNotEmpty=ifNotEmpty
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\codec\ber\encoder.py", line 61, in encode
    encodeFun, value, defMode, maxChunkSize, ifNotEmpty=ifNotEmpty
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\codec\cer\encoder.py", line 156, in encodeValue
    substrate = encodeFun(value[idx], defMode, maxChunkSize, namedTypes[idx].isOptional) + substrate
  File "C:\Program Files\Anaconda3\lib\site-packages\pyasn1\type\namedtype.py", line 155, in __getitem__
    return self.__namedTypes[idx]
IndexError: tuple index out of range

Maybe, it has to do how I use it, maybe it is a real bug.

By the way, this is how I use it: https://github.com/androguard/androguard/blob/master/androguard/core/bytecodes/apk.py#L836 I also need to remove the first identifier in the DER Coded sequence, which does not look right, but I did not found another way. (If you know a better way to extract the cert from the message please tell me 😃)