Fix pushed to master. Updated graph:

Is large change to cipher API really needed (new open/encrypt with less flexibility)? How that would affect performance? Would following new interfaces to gcry_cipher API work instead?

• gcry_cipher_setup_geniv(hd, int ivlen, int method): for setting up IV generator with parameters such as IV length, method id (RFC5116, TLS 1.3, SSH, etc), (other parameters?)
• gcry_cipher_geniv(hd, byte *outiv): for generating new iv: generate IV using select method, set IV internally and output generated IV to 'ivout'.
• gcry_cipher_genkey(hd, byte *outkey, int keylen, int method): for generating keys, generate key internally with parameters (method id, other?), setup key internally and output generated key to 'outkey'. (how keys from key exchange protocol be handled? using existing setkey?)

I went through my test files and found that --enarmor on zero length input file did no longer work. I made separate patch to fix that issue, which then also needs another approach for handling compress issue noticed earlier:

Does this look ok to push to master? @werner @gniibe

New versions of patches 0005 and 0006 - fixes EOF handling issues noticed with compression/decompression:

Does these patches look ok? @gniibe @werner

I used "1<<30" by example of existing code in g10/free-packet.c, which is another place where iobuf_read is reading to NULL.

(note: -O2 is added only for compiling powerpc vector implementation files)

I added check to configure.ac for missing -O flag and tests with -O2. If adding -O2 does not help, then powerpc vector implementations wont be build at all.

Does the patches look ok to push to master? @werner @gniibe

Thanks. All my tests work now.

Just more background what I'm doing with these tests. I started testing with set of different sized test files (generated from urandom) to detect any bugs in my changes, which try to reduce amount of memory copies in iobuf_read/iobuf_write. Size ranges for these test-files are 0...17408, 32256...66560 and 130560...132096 bytes. These files are encrypted with different settings (public key/symmetric/cfb/ocb/different algos) and then decrypted and decrypted file compared to original.

I tested the fix. It appears to break OCB encrypting files shorter than 65515 bytes:

$ gpg --batch --symmetric --passphrase=bug --output=enc_065514.gpg --rfc4880bis --force-aead --cipher-algo AES128 --compress-algo none plain_065514
$ ls -laF *065514*
-rw-rw-r-- 1 jussi jussi   100 Feb  22 18:51 enc_065514.gpg
-rw-rw-r-- 1 jussi jussi 65514 Feb  22 18:42 plain_065514
$ sha256sum plain_065514
5711955703f4d96f510ad5a660c3ccd0d01f0b2dd2561ba6586159ad941cbcde  plain_065514
$ gpg --batch --decrypt --passphrase=bug --output=- enc_065514.gpg | sha256sum
gpg: AES.OCB encrypted session key
gpg: encrypted with 1 passphrase
e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855  -

Benchmarking blog post that I linked tested GnuPG in symmetric mode, gpg --symmetric. I think symmetric case is important too from performance point of view, there is tools that use gpg --symmetric as bulk encryption/decryption backend (for example duplicity backup tool). Such encrypted files have tag3 (symmetric-key ESK) packet followed tag18 (encrypted and MDC) packet. Could existence of Tag18 packet in input be used as marker for input being rfc4880 and allow disabling those extra hash contexts? As I understand those hashes should not be needed with rfc4880 input (but I don't know all the historical details).

I planned to reply to your email on mailing-list, but I just have too little time.

Thanks for report. Those powerpc vector implementations expect that compiler optimizations are enabled and here provided CFLAGS did not have '-Ox' parameter. This could be worked around by introducing -O2 always when building those files (confiugre.ac & cipher/Makefile.am change) or using 'optimize' attributes to required functions (cipher/*-ppc*.c change).

Thanks for report. I got similar report earlier this week from gentoo user through email and made following patch for them to test. I'll push it to master soon.

Ok, I'll add.

DCO has not appeared on mailing-list. You can this from check list archives, https://lists.gnupg.org/pipermail/gcrypt-devel/2021-December/thread.html

I did some finishing touches on coding style:

Few comments on new patch:

Thanks, however I didn't see your email on mailing-list. Maybe the email got stuck on the way.