Why does GPG not like this encrypted message?

I had the following encrypted message laying around on my computer from back when I was playing around with GPG (and in this case, Enigmail)

-----BEGIN PGP MESSAGE-----
Charset: ISO-8859-15
Version: GnuPG v2.0.20 (MingW32)
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

.............+AWJjL0Un8xWK0lFgw26Oos
ynzsVjy9fZAVlzoVN3XgucjIG8guTrakLbbvF0aMwDIwUXb3x1b+4hGNmkx+TUQV
kE6WcnnJw5B+8/m3CQ+IxbalHKAOu7VRHZ7XJCvY6dLAIQGSmwx77S3TV4zKH5PR
p3e15GJbcM+Gfo9Ka8u6KtGZALEk9xsZjH3QmfyB66dARp4/u7gJZrJ9hd5bzXJ9
LfjEvqygdpTeak2etz+r90WbiC/P4mnXQoxz7s3m1nJESb6VcpipJFkfwFdl1BYx
0XVfY/uH/gkQGiPNQL.....................O87w==
=Cnbj
-----END PGP MESSAGE-----

If I attempt to run gpg --list-packets or gpg --decrypt on the message, I get the following output (with the "invalid character skipped" warning repeated about thirty times):

gpg: invalid radix64 character 2E skipped
gpg: invalid radix64 character 2E skipped
gpg: invalid radix64 character 2E skipped
gpg: invalid radix64 character 2E skipped
gpg: CRC error; A3E958 - 0A76E3
gpg: [don't know]: invalid packet (ctb=3a)

Why does GPG not like this message? What is wrong with it?

IQAndreas

Posted 2014-11-14T20:56:03.540

Reputation: 2 317

Answers

ASCII-armored OpenPGP messages are represented in Radix-64 (Base64 variation with checksum added), which doesn't have the dot symbol ., so obviously the data is simply corrupted.

Based on sequential repetition of the same character it is also likely the message was purposely edited to obscure it.

JohnKiller

Posted 2014-11-14T20:56:03.540

Reputation: 143

@jens-erat thanks for the edit, guess I still have a lot to learn :) – JohnKiller – 2014-11-14T21:54:36.763

-----BEGIN PGP MESSAGE----- Version: OpenPGP.js v2.5.13 Comment: https://openpgpjs.org , this was the problem , just remove and all will work.

– waza123 – 2018-03-09T14:07:46.513

This error message could be caused by extra line breaks being added to the message after it was encrypted. I got a similar error message for this cause.

To avoid this issue for a combination of mailvelope and gmail / Google Inbox, encrypt the message as a file and attach the file. It would seem plausible that this is a work around for other scenarios.

This blog provides a more in-depth explanation.

Edward Moffett

Posted 2014-11-14T20:56:03.540

Reputation: 101