This library provides easy to use functions for encryption/decryption
among other things. There is some overlap with things that
OpenSSL also provides but not all.
Note: the only change between 5.0.9 and 5.0.9.1 is:
* Build improvements on *NIX (faster compiling and lower memory requirements)
* Windows version is unchanged and still 5.0.9
And if it is actually used/installed then make it a little bit
harder to bypass the case where the digitale signature does not match.
And yes, the bypass option does exist because in the future we
may have a different signing key. Who knows from what old version
people may upgrade years from now, after all.
version or newer on the sytem, otherwise we fall back to shipped version.
This fixes https://bugs.unrealircd.org/view.php?id=5187 among others.
It means:
* Case insensitive matches work better in UTF8 now, such as extended Latin.
For example, a spamfilter on "ę" now also matches "Ę", while previously
it did not catch this.
* Other PCRE2 features such as https://www.pcre.org/current/doc/html/pcre2syntax.html#SEC5
are now available. For example you can now set a spamfilter with the regex
\p{Arabic} to block all Arabic script, or
\p{Cyrillic} to block all Cyrillic script (such as Russian)
Use these new tools with care, of course. Blocking an entire language,
or script, is quite a drastic measure.
All of this was possible because of the new PCRE2_MATCH_INVALID_UTF
compile time option which was introduced in PCRE2 10.34.
This also means we now require at least that PCRE2 version so
everyone can benefit from this new spamfilter UTF8 feature.
Many systems come with older PCRE2 versions so this means we will
fall back to the shipped PCRE2 version in UnrealIRCd. This means
./Config will take a little longer to compile things.
Although there is no indication as of now, but if this feature would
break things heavily then it might get reverted or configurable.
This is also why it was added just after 5.0.4 release and not right
before it, it needs some heavy testing.
Bram Matthys