I notice github actions's environment has no mbedtls, may I build mbedtls in CI too?

You should be able to just add something like apt-get -q -y install mbedtls-dev to the github-actions build prep steps.

https://github.com/libevent/libevent/pull/1028/checks?check_run_id=712190097
It seem like cmake build dir shouldn't be cache?
because source dir may be different.

It seem like cmake build dir shouldn't be cache?

It should, otherwise it will make build significantly slower (especially on CI)
@ygj6 working on fixing this

As a workaround for this PR you can change cache key

In general looks good, but lots of copy-paste in bufferevent_mbedtls.c can you reduce it please? (and it is not only to make code clean but also bufferevent_openssl.c contains some quirks/issues that I would love to keep in one place to avoid out-of-sync problems)

I also think that current implementation is ugly, and need to reuse some logic from openssl.
but how can I locate all issue/quirks from bufferevent_openssl.c?
sorry for unfamiliar.

but how can I locate all issue/quirks from bufferevent_openssl.c?

How about move generic code out from the bufferevent_openssl and use it for both openssl and mbedtls, thus you will avoid copy-pasting?
And after this that generic parts can be cleaned up, separately

but how can I locate all issue/quirks from bufferevent_openssl.c?

How about move generic code out from the bufferevent_openssl and use it for both openssl and mbedtls, thus you will avoid copy-pasting?
And after this that generic parts can be cleaned up, separately

there is a problem when reuse code with openssl and mbedtls.
that is we can't link libevent_openssl and libevent_mbedtls together,
although this situation is rarely.
or we have to add one more library like libevent_ssl_common

or we have to add one more library like libevent_ssl_common

Sound ok, but this library should not be exported, only archive or cmake object

If we don't export libevent_ssl_common, we can't link libevent_openssl and libevent_mbedtls together.
May I mistake something?

If we don't export libevent_ssl_common, we can't link libevent_openssl and libevent_mbedtls together

They will just both contains the same code in the library, this is how archive library works

P.S. maybe I misunderstand you?

I review code of bufferevent_openssl.c and bufferevent_mbedtls.c.
And I found that it's too hard to reuse some code in two file directly.
they has similar but different struct/function/error code.
If we want reuse code between SSL library, we must make an abstract layer of SSL which encapsulation implementation of OpenSSL and mbedtls.
That's a little bigger for this PR.
can we do it after this PR?

can we do it after this PR?

Ok

windows CI is OK all now, maybe you mistake link? https://github.com/libevent/libevent/actions/runs/168370501

@okhowang Ok, will address those minor bits by myself

@okhowang thanks a lot for this functionality!

BTW can you also add:

• tests for https using mbed TLS layer?
• https-client mbed TLS support

@okhowang thanks a lot for this functionality!

BTW can you also add:

• tests for https using mbed TLS layer?
• https-client mbed TLS support

I will do it later.

Plus there are also the following warnings:

[26/195] Building C object CMakeFiles/event_openssl_static.dir/bufferevent_openssl.c.o
../bufferevent_openssl.c:402:2: warning: cast between incompatible function types from ‘int (*)(const SSL *)’ {aka ‘int (*)(const struct
 ssl_st *)’} to ‘size_t (*)(void *)’ {aka ‘long unsigned int (*)(void *)’} [-Wcast-function-type]
  402 |  (size_t(*)(void *))SSL_pending,
      |  ^
[27/195] Building C object CMakeFiles/event_openssl_shared.dir/bufferevent_openssl.c.o
../bufferevent_openssl.c:402:2: warning: cast between incompatible function types from ‘int (*)(const SSL *)’ {aka ‘int (*)(const struct
 ssl_st *)’} to ‘size_t (*)(void *)’ {aka ‘long unsigned int (*)(void *)’} [-Wcast-function-type]
  402 |  (size_t(*)(void *))SSL_pending,

https-client mbed TLS support

https-client is based on OpenSSL currently,
and there is a ssl-client-mbedtls.c.
you mean I need add a https-client-mbedtls?
@azat

you mean I need add a https-client-mbedtls?

@okhowang This will be okay too (if this will be done w/o copy-paste, or with minimal copy-paste)

P.S. sorry for the delay