The bug was introduced in 806dbb02 (a wrong value was passed in as the
first argument to the default callback in our wrapper).

When NSS-powered libcurl connected to a SSL server with
CURLOPT_SSL_VERIFYPEER equal to zero, NSS remembered that the peer
certificate was accepted by libcurl and did not ask the second time when
connecting to the same server with CURLOPT_SSL_VERIFYPEER equal to one.

This patch turns off the SSL session cache for the particular SSL socket
if peer verification is disabled.  In order to avoid any performance
impact, the peer verification is completely skipped in that case, which
makes it even faster than before.

Bug: https://bugzilla.redhat.com/678580

Flaw introduced in fc77790b and present in curl-7.21.4.
Bug: https://bugzilla.redhat.com/669702#c16

... in case more than one CA is loaded.

Bug: https://bugzilla.redhat.com/670802

... and update the curl.1 and curl_easy_setopt.3 man pages such that
they do not suggest to use an OpenSSL utility if curl is not built
against OpenSSL.

Bug: https://bugzilla.redhat.com/669702

As the function doesn't really use the connectdata struct but only the
SessionHanadle struct I modified what argument it wants.

Bug: https://bugzilla.redhat.com/623663

Since some systems don't have PATH_MAX and it isn't that clever to
assume a fixed maximum path length, the code now allocates buffer space
instead of using stack.

Reported by: Samuel Thibault
Bug: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=608521

When configured with '--without-ssl --with-nss', NTLM authentication
now uses NSS crypto library for MD5 and DES.  For MD4 we have a local
implementation in that case.  More details are available at
https://bugzilla.redhat.com/603783

In order to get it working, curl_global_init() must be called with
CURL_GLOBAL_SSL or CURL_GLOBAL_ALL.  That's necessary because NSS needs
to be initialized globally and we do so only when the NSS library is
actually required by protocol.  The mentioned call of curl_global_init()
is responsible for creating of the initialization mutex.

There was also slightly changed the NSS initialization scenario, in
particular, loading of the NSS PEM module.  It used to be loaded always
right after the NSS library was initialized.  Now the library is
initialized as soon as any SSL or NTLM is required, while the PEM module
is prevented from being loaded until the SSL is actually required.

FTP(S) use two connections that can be set to different recv and
send functions independently, so by introducing recv+send pairs
in the same manner we already have sockets/connections we can
work with FTPS fine.

This commit fixes the FTPS regression introduced in change d64bd82b.

Howard Chu brought the bulk work of this patch that properly
moves out the sending and recving of data to the parts of the
code that are properly responsible for the various ways of doing
so.

Daniel Stenberg assisted with polishing a few bits and fixed some
minor flaws in the original patch.

Another upside of this patch is that we now abuse CURLcodes less
with the "magic" -1 return codes and instead use CURLE_AGAIN more
consistently.

  a broken TLS server. However it does not happen if SSL version is selected
  manually. The approach was originally taken from PSM. Kaspar Brand helped me
  to complete the patch. Original bug reports:
  https://bugzilla.redhat.com/525496
  https://bugzilla.redhat.com/527771

  closed NSPR descriptor. The issue was hard to find, reported several times
  before and always closed unresolved. More info at the RH bug:
  https://bugzilla.redhat.com/534176

  in non-blocking mode.

false positive on a leaked socket, so this introduces a way to tell the system
that the socket is indeed closed without explicitly closing it!

  libcurl called NSS to close the SSL "session" it also closed the actual
  socket.

added support for new SQLite cert database format: added a runtime check for version 3.12.0, and depending on the result add 'sql:' prefix to cert database directory so that newer SQLIte database format works.

added aditional check for the directory specified with SSL_DIR, and fall back to hardcoded directory if not a valid directory.

  libcurl-NSS. Originally reported at:
  https://bugzilla.redhat.com/show_bug.cgi?id=516056#c9

  verbose error messages. Originally reported at:
  https://bugzilla.redhat.com/show_bug.cgi?id=516056

  in NSS-powered libcurl. Now the client certificates can be selected
  automatically by a NSS built-in hook. Additionally pre-login to all PKCS11
  slots is no more performed. It used to cause problems with HW tokens.

- Fixed reference counting for NSS client certificates. Now the PEM reader
  module should be always properly unloaded on Curl_nss_cleanup(). If the unload
  fails though, libcurl will try to reuse the already loaded instance.

  issue with client certs that caused issues like segfaults.
  http://curl.haxx.se/mail/lib-2009-05/0316.html

  PK11_CreateGenericObject() function.