... and fix some typos from the 62d15f15 commit.

Allow an appliction to set libcurl specific SSL options. The first and
only options supported right now is CURLSSLOPT_ALLOW_BEAST.

It will make libcurl to disable any work-arounds the underlying SSL
library may have to address a known security flaw in the SSL3 and TLS1.0
protocol versions.

This is a reaction to us unconditionally removing that behavior after
this security advisory:

http://curl.haxx.se/docs/adv_20120124B.html

... it did however cause a lot of programs to fail because of old
servers not liking this work-around. Now programs can opt to decrease
the security in order to interoperate with old servers better.

This adds three new options to control the behavior of TCP keepalives:

- CURLOPT_TCP_KEEPALIVE: enable/disable probes
- CURLOPT_TCP_KEEPIDLE: idle time before sending first probe
- CURLOPT_TCP_KEEPINTVL: delay between successive probes

While not all operating systems support the TCP_KEEPIDLE and
TCP_KEEPINTVL knobs, the library will still allow these options to be
set by clients, silently ignoring the values.

When CURLOPT_REFERER has been used, curl_easy_reset() did not properly
clear it.

Verified with the new test 598

Bug: http://curl.haxx.se/bug/view.cgi?id=3481551
Reported by: Michael Day

When the target host was given as a IPv6 numerical address, it was not
properly put within square brackets for the Host: header in the CONNECT
request. The "normal" request did fine.

Reported by: "zooloo"
Bug: http://curl.haxx.se/bug/view.cgi?id=3482093

When connecting to a domain with multiple IP addresses, allow different,
decreasing connection timeout values. This should guarantee some
connections attempts with sufficiently long timeouts, while still
providing fallback.

With advice from Nikos Mavrogiannopoulos, changed the priority string to
add "actual priorities" and favour ARCFOUR. This makes libcurl work
better when enforcing SSLv3 with GnuTLS. Both in the sense that the
libmicrohttpd test is now working again but also that it mitigates a
weakness in the older SSL/TLS protocols.

Bug: http://curl.haxx.se/mail/lib-2012-01/0225.html
Reported by: Christian Grothoff

Protocols (IMAP, POP3 and SMTP) that use the path part of a URL in a
decoded manner now use the new Curl_urldecode() function to reject URLs
with embedded control codes (anything that is or decodes to a byte value
less than 32).

URLs containing such codes could easily otherwise be used to do harm and
allow users to do unintended actions with otherwise innocent tools and
applications. Like for example using a URL like
pop3://pop3.example.com/1%0d%0aDELE%201 when the app wants a URL to get
a mail and instead this would delete one.

This flaw is considered a security vulnerability: CVE-2012-0036

Security advisory at: http://curl.haxx.se/docs/adv_20120124.html

Reported by: Dan Fandrich

OpenSSL added a work-around for a SSL 3.0/TLS 1.0 CBC vulnerability
(http://www.openssl.org/~bodo/tls-cbc.txt). In 0.9.6e they added a bit
to SSL_OP_ALL that _disables_ that work-around despite the fact that
SSL_OP_ALL is documented to do "rather harmless" workarounds.

The libcurl code uses the SSL_OP_ALL define and thus logically always
disables the OpenSSL fix.

In order to keep the secure work-around workding, the
SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS bit must not be set and this change
makes sure of this.

Reported by: product-security at Apple

Using a URL with embedded user name and password didn't work if the host
was given as a numerical IPv6 string, like ftp://user:password@[::1]/

Reported by: Brandon Wang
Bug: http://curl.haxx.se/mail/archive-2012-01/0047.html

avoid checking preprocessor definition official value

Apparently ssl_get_ciphersuite() is needed to get the name of the used
cipher suite.

The value was turned negative when it shouldn't have been

... it is now named havege_random!

Reported by: Robert Schumann
Bug: http://curl.haxx.se/mail/lib-2012-01/0178.html

Fix a bug where input was read from stdin even when a different FILE *
had been configured via CURLOPT_READDATA

bug: http://curl.haxx.se/bug/view.cgi?id=3474308

Leak triggered when CURLOPT_SSLCERTTYPE and CURLOPT_SSLKEYTYPE set to P12
and both CURLOPT_SSLCERT and CURLOPT_SSLKEY point to the same PKCS#12 file.

SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG option enabling allowed successfull
interoperability with web server Netscape Enterprise Server 2.0.1 released
back in 1996 more than 15 years ago.

Due to CVE-2010-4180, option SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG has
become ineffective as of OpenSSL 0.9.8q and 1.0.0c. In order to mitigate
CVE-2010-4180 when using previous OpenSSL versions we no longer enable
this option regardless of OpenSSL version and SSL_OP_ALL definition.

Some functions using getaddrinfo and gethostbyname were still
mistakingly being used/linked even if c-ares was selected as resolver
backend.

Reported by: Arthur Murray
Bug: http://curl.haxx.se/mail/lib-2012-01/0160.html

Test 161 updated accordingly

Previously the code would create a dummy socket while resolving just to
have curl_multi_fdset() return something but the non-win32 version
doesn't do it this way and the creation and use of a socket that isn't
made with the common create-socket callback can be confusing to apps
using the multi_socket API etc.

This change removes the dummy socket and thus will cause
curl_multi_fdset() to return with maxfd == -1 more often.

With this change, curl compiles with the new OPENSSL_NO_SSL_INTERN
cflag. This flag might become the default in some distant future.

Fixed a problem in POP3 and IMAP where a connection would fail when
CURLUSESSL_TRY was specified for a server that didn't support
SSL/TLS connections rather than continuing.

The STARTTLS response code in SMTP, POP3 and IMAP would return
CURLE_LOGIN_DENIED rather than CURLE_USE_SSL_FAILED when SSL/TLS
was not available on the server.

Reported by: Gokhan Sengun
Bug: http://curl.haxx.se/mail/lib-2012-01/0018.html

Unfortunately we have no test cases for this and I have no SSPI build or
server to verify this with. The change seems simple enough though.

Bug: http://curl.haxx.se/bug/view.cgi?id=3466497
Reported by: Patrice Guerin

When the buffer gets realloced to hold the file name in the
SSH_SFTP_READDIR_LINK state, the counter was not bumped accordingly.

Reported by: Armel Asselin
Patch by: Armel Asselin
Bug: http://curl.haxx.se/mail/lib-2011-12/0249.html

... to make sure the DNS cache is properly case insensitive

When a HTTP connection is re-used for a subsequent request without
proxy, it would always re-use the Host: header of the first request. As
host names are case insensitive it would make curl send another host
name case that what the particular request used.

Now it will instead always use the most recent host name to always use
the desired casing.

Added test case 1318 to verify.

Bug: http://curl.haxx.se/mail/lib-2011-12/0314.html
Reported by: Alex Vinnik