Merge r1526168, r1527291, r1527295, r1563420, r1588851, r1666363, r1679470

Merge r1526168, r1527291, r1527295, r1563420, r1588851, r1666363, r1679470

r1526168 | kbrand | 2013-09-25 14:52:35 +0200 (Wed, 25 Sep 2013) | 21 lines

Streamline ephemeral key handling:

- drop support for ephemeral RSA keys (only allowed/needed
  for export ciphers)

- drop pTmpKeys from the per-process SSLModConfigRec, and remove
  the temp key generation at startup (unnecessary for DHE/ECDHE)

- unconditionally disable null and export-grade ciphers by always
  prepending "!aNULL:!eNULL:!EXP:" to any cipher suite string

- do not configure per-connection SSL_tmp_*_callbacks, as it is
  sufficient to set them for the SSL_CTX

- set default curve for ECDHE at startup, obviating the need
  for a per-handshake callback, for the time being (and also
  configure SSL_OP_SINGLE_ECDH_USE, previously left out)

For additional background, see
https://mail-archives.apache.org/mod_mbox/httpd-dev/201309.mbox/%3C52358ED1.2070704@velox.ch%3E

r1527291 | kbrand | 2013-09-29 11:36:31 +0200 (Sun, 29 Sep 2013) | 9 lines

Follow-up fixes for r1526168:

- drop SSL_TMP_KEY_* constants from ssl_private.h, too

- make sure we also disable aNULL, eNULL and EXP ciphers
  for per-directory SSLCipherSuite directives

- apply the same treatment to SSLProxyCipherSuite

r1527295 | kbrand | 2013-09-29 12:35:46 +0200 (Sun, 29 Sep 2013) | 20 lines

Improve ephemeral key handling (companion to r1526168):

- allow to configure custom DHE or ECDHE parameters via the
  SSLCertificateFile directive, and adapt its documentation
  accordingly (addresses PR 49559)

- add standardized DH parameters from RFCs 2409 and 3526,
  use them based on the length of the certificate's RSA/DSA key,
  and add a FAQ entry for clients which limit DH support
  to 1024 bits (such as Java 7 and earlier)

- move ssl_dh_GetParamFromFile() from ssl_engine_dh.c to
  ssl_util_ssl.c, and add ssl_ec_GetParamFromFile()

- drop ssl_engine_dh.c from mod_ssl

For the standardized DH parameters, OpenSSL version 0.9.8a
or later is required, which was therefore made a new minimum
requirement in r1527294.

r1563420 | kbrand | 2014-02-01 15:04:23 +0100 (Sat, 01 Feb 2014) | 3 lines

enable auto curve selection for ephemeral ECDH keys
when compiled against OpenSSL 1.0.2 or later

r1588851 | kbrand | 2014-04-21 08:39:24 +0200 (Mon, 21 Apr 2014) | 3 lines

ssl_callback_TmpDH: for OpenSSL 1.0.2 and later, set the current cert to the
one actually used for the connection before calling SSL_get_privatekey(ssl)

r1666363 | jkaluza | 2015-03-13 08:32:46 +0100 (Fri, 13 Mar 2015) | 4 lines

* mod_ssl: fix small memory leak in ssl_init_server_certs when ECDH is used.
SSL_CTX_set_tmp_ecdh increases reference count, so we have to call EC_KEY_free,
otherwise eckey will not be freed.

r1679470 | ylavic | 2015-05-15 00:38:20 +0200 (Fri, 15 May 2015) | 5 lines

mod_ssl: follow up to r1527291.
Always prepend "!aNULL:!eNULL:" to SSL_DEFAULT_CIPHER_LIST (default for
SSL[Proxy]CipherSuite) since we support OpenSSL versions where this was
not yet included by default.

Reviewed by: ylavic, wrowe, rjung
Backported by: ylavic

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1680916 13f79535-47bb-0310-9956-ffa450edef68