Since around 2018, we have been using spaces for indentation for newly
added code[1]. The mixed use of tabs and spaces has repeatedly confused
new contributors who configured their editors to use a different tab
size than 8. Since git blame can now skip specific commits, ruby/ruby
did a mass reformatting of tabs in 2022[2]. Do the same in ruby/openssl.

While at it, fix a few indentation issues, mainly in switch-case labels
and in ossl_ssl_session.c, which used doubled indentation size.

This patch contains white-space changes only. git diff -w output should
be empty.

[1] https://bugs.ruby-lang.org/issues/14246
[2] https://bugs.ruby-lang.org/issues/18891

https://github.com/ruby/openssl/commit/4d6214f507

These declarations were added to every source file because older
versions of RDoc did not resolve ancestor tree across files. Since
RDoc 6.9.0 supports this, this workaround is no longer needed.

    https://redirect.github.com/ruby/rdoc/pull/1217

https://github.com/ruby/openssl/commit/6491ce63be

With the introduction of OpenSSL 3 providers, newly implemented
algorithms do not necessarily have a corresponding NID assigned. To use
such an algorithm, it has to be "fetched" from providers using the new
EVP_*_fetch() functions.

For digest algorithms, we have to use EVP_MD_fetch() instead of the
existing EVP_get_digestbyname(). However, it is not a drop-in
replacement because:

 - EVP_MD_fetch() does not support all algorithm name aliases recognized
   by EVP_get_digestbyname().

 - Both return an EVP_MD, but the one returned by EVP_MD_fetch() is
   sometimes reference counted and the user has to explicitly release
   it with EVP_MD_free().

So, keep using EVP_get_digestbyname() for all OpenSSL versions for now,
and fall back to EVP_MD_fetch() if it fails. In the latter case, prepare
a T_DATA object to manage the fetched EVP_MD's lifetime.

https://github.com/ruby/openssl/commit/9fc2179403

https://github.com/ruby/openssl/commit/17f87d2cf0

Drop support for OpenSSL 1.1.0. OpenSSL 1.1.0 was a non-LTS release and
it has reached upstream EOL in 2019-12 along with OpenSSL 1.0.2.
Distributions that shipped with OpenSSL 1.1.0 include:

 - Debian 9 (EOL 2022-06)
 - Ubuntu 18.04 LTS (EOL 2023-04)

https://github.com/ruby/openssl/commit/ba83abe920

https://github.com/ruby/openssl/commit/85d6b7f192

Update the references to the file "LICENCE" with "COPYING".

The file LICENCE doesn't exist in ruby/ruby nor ruby/openssl. This has
been always the case since OpenSSL for Ruby 2 was merged to the ruby
tree as a standard library in 2003.

In OpenSSL for Ruby 2's CVS repository[1], the LICENCE file contained
an old version of the Ruby License, identical to the COPYING file that
was in Ruby's tree at that time (r4128[2]).

[1] http://cvs.savannah.gnu.org/viewvc/rubypki/ossl2/LICENCE?revision=1.1.1.1&view=markup
[2] https://github.com/ruby/ruby/blob/231247c010acba191b78ed2d1310c935e63ad919/COPYING

https://github.com/ruby/openssl/commit/5bccf07d04

The vast majority have no reference so it's just a matter of setting the flags.

For the couple exception, they have very little references so it's
easy.

https://github.com/ruby/openssl/commit/2c7c6de69e

Current OpenSSL 3.0.x release has a regression with zero-length MAC
keys. While this issue should be fixed in a future release of OpenSSL,
we can use EVP_PKEY_new_raw_private_key() in place of the problematic
EVP_PKEY_new_mac_key() to avoid the issue. OpenSSL 3.0's man page
recommends using it regardless:

> EVP_PKEY_new_mac_key() works in the same way as
> EVP_PKEY_new_raw_private_key().  New applications should use
> EVP_PKEY_new_raw_private_key() instead.

Fixes https://github.com/ruby/openssl/issues/369#issuecomment-1224912710

https://github.com/ruby/openssl/commit/4293f18b1f

According to the manpage, the "siglen" parameter must be initialized
beforehand.

https://github.com/ruby/openssl/commit/6a60c7b2e7