nauta.cu users cannot connect with core 1.156.1

[link2xt]

The failure looks like this:

Manually setting strict_tls to false reportedly solved the problem, but normaly strict_tls should be set for nauta because it is a recognized provider that has strict_tls disabled: https://github.com/deltachat/deltachat-core-rust/blob/2ee83bf78629d67ee260ec371013494a293f1e32/src/provider/data.rs#L1003

There was a change #6186 in core 1.151.0, but this should keep using OpenSSL on Android instead of Rustls if strict_tls is disabled.

If the users upgraded from a previous Android release this must have been an upgrade from core 1.155.4. Core 1.151.0 was some time ago.
Since it is ArcaneChat, it should have been core 1.155.5.

[link2xt]

82ea4e2 updated openssl-src from 300.3.0+3.3.0 to 300.4.2+3.4.1.
That was between 1.155.6 and 1.156.0.
I don't see anything deprecated in https://openssl-library.org/news/openssl-3.4-notes/ that can make it incompatible.

[link2xt]

From the log submitted by users, this is what happens when attempting to configure a new account:

03-01 17:50:32.455 20058  7290 🟠 DeltaChat: [accId=72] src/imap/client.rs:151: Failed to connect to imap.nauta.cu (181.225.231.14:143): STARTTLS upgrade failed: OpenSSL error.
03-01 17:50:32.455 20058  7290 🟠 DeltaChat: [accId=72] src/imap.rs:354: IMAP failed to connect: STARTTLS upgrade failed: OpenSSL error.
03-01 17:50:32.455 20058  7290 🟠 DeltaChat: [accId=72] deltachat-ffi/src/lib.rs:449: Configure failed: STARTTLS upgrade failed

Same for SMTP:

03-01 17:50:32.540 20058  7290 🟠 DeltaChat: [accId=72] src/smtp/connect.rs:131: Failed to connect to smtp.nauta.cu (181.225.231.12:25): STARTTLS upgrade failed: OpenSSL error.
03-01 17:50:32.540 20058  7290 🟠 DeltaChat: [accId=72] src/smtp.rs:145: SMTP failed to connect and authenticate: SMTP failed to connect: STARTTLS upgrade failed: OpenSSL error.

So it is not that we accidentally switched to Rustls, but OpenSSL upgrade broke things likely.

[link2xt]

The error is also bad, this is where "OpenSSL error" seems to come from:
https://github.com/sfackler/rust-openssl/blob/acd312c2dd29e5bc7995f99c238a26169944eb6e/openssl/src/ssl/error.rs#L118

[link2xt]

It is reproducible.
On Android if you go into classic login, type whatever as a login @nine.testrun.org and whatever password (it is not used anyway because TLS fails) and select "accept invalid certificates", it fails configuration with "Configuration failed. Error: OpenSSL error". On desktop seems to work.

[link2xt]

Looks like it got broken in 1.156.0 with 67f768f which upgraded native-tls from 0.2.11 to 0.2.13. The problem is fixed in native-tls 0.2.14: sfackler/rust-native-tls#324