How can I extract an attachment from the email body (encoded as base64)

Question

How can I extract attachments from an email when they arrive encoded in the body of the email like this:

------ =_NEXTPART_FORMSCAPE_MAIL_message101122101615
Content-Type: application/octet-stream; name="MyFile_hasalongish
     filename_22-NOV-2010.pdf"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="MyFile_hasalongishfilename_22-NOV-2010.pdf"
Content-Description: MyFile_hasalongishfilename_22-NOV-2010.pdf

JVBEDi0xLjMKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0
ZFRGVSdsfSDF43N0cmVhbQp4nJ0b23IVN/LdXzG1D7vnbOUMo9tISiWpBduAN2CMbZJN
[...]
OUIwOEYxRDcyRjkwRDAxRUU1QzBDMjhEM0Y+XQo+PgpzdGFydHhyZWYKMTMwNDQKJSVF
T0YK
------ =_NEXTPART_FORMSCAPE_MAIL_message101122101615--

You'll need to find a UUDECODE tool to convert the ASCII to a valid file. — , Nov 22 '10 at 00:37
On what operating system, or with what mail architecture (local unix delivery, fetchmail, Thunderbird, Outlook, ...)? — Gilles 'SO- stop being evil', Nov 22 '10 at 00:52

score 21 · Answer 1 · answered Oct 21 '13 at 23:37

21

Copy only the base64 encoded text into a new text file foo.txt.

base64 --decode foo.txt > bar.pdf

I just decoded a base64 stream that had an extra bit on the end that I had to remove. It looked like this: --=_59494bda030d4629113a60ff13935d81--. Before I removed it I got the error: Invalid character in input stream. After I deleted it, no decoding errors and it opened just fine.

answered Oct 21 '13 at 23:37

Simon Woodside

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Also if facing `invalid input` errors, some might find useful to add `--ignore-garbage` (or just `-i`) flag – deevee Nov 16 '21 at 08:51
The @deevee tip worked like a charm to me, thanks! – Charles Santos Aug 09 '23 at 16:23

score 4 · Accepted Answer · edited Feb 05 '15 at 22:34

4

Save the email to a text file with the extension .uue and extract the attachment with a de-archiver.

edited Feb 05 '15 at 22:34

Giacomo1968

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answered Nov 22 '10 at 00:38

Rob Kam

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score 1 · Answer 3 · answered Nov 22 '10 at 00:47

1

I was able to recover the file using a base64 decoder and copying only the actual text that was the encoded attachment, not any of the surrounding header/footer stuff.

answered Nov 22 '10 at 00:47

DrStalker

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How can I extract an attachment from the email body (encoded as base64)

3 Answers3