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handle PKCS#7 CompressedData #66
Description
gmime currently has some commented out/unimplemented functions for handling PKCS#7 CompressedData messages. These should be implemented, so i'm just recording that as an open issue.
The functions in particular are:
g_mime_application_pkcs7_mime_compressg_mime_application_pkcs7_mime_decompress
for specification reference, see § 3.6 of RFC 8551
Activity
jstedfast commentedon Dec 2, 2019
Yea, I think I aborted my efforts on support for this because I wasn't sure how to do it using GpgME.
dkg commentedon Dec 3, 2019
I don't think it should require gpgme at all -- compression and decompression are completely unrelated to cryptography, they just happen to use the same PKCS#7 framing.
jstedfast commentedon Dec 9, 2019
Sure, but I was hoping gpgme supported it because otherwise I need to implement asn1 myself.
Maybe I can use libksba, but that looks like it's missing some API that might be needed. Hard to tell right now.
I'll also need to add new virtual methods for this (theoretically), so this may be best as a v4.0 API as well.
sakwaa commentedon Mar 27, 2020
Are there any updates to the implementation for the compress/decompress? I ran into the same issue.. I have a multipart/signed part with a compressed message and I can't figure out how to decompress to get the message contents as readable text. Thanks!
jstedfast commentedon Mar 27, 2020
No updates. I haven't had enough free time to look into this yet.
Implement CMS CompressedData support
jstedfast commentedon Oct 28, 2026
Implemented in commit 3e12c5d on v4.0-dev. Adds RFC 3274 CMS CompressedData compression and DER/BER decompression using zlib, without requiring a crypto backend. Decompression requires an explicit expanded-size limit and validates nesting, checksums, truncation, and trailing data. Verified with regression tests, two-way OpenSSL interoperability, and sanitizer tests with and without crypto support.