According to https://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-05
it is "http/1.1" and not "http/1.0".

Add ALPN support when using GnuTLS >= 3.2.0. This allows
libcurl to negotiate HTTP/2.0 for https connections when
built with GnuTLS.

See:
http://www.gnutls.org/manual/gnutls.html#Application-Layer-Protocol-Negotiation-_0028ALPN_0029
http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-04

When doing multi-part formposts, libcurl used a pseudo-random value that
was seeded with time(). This turns out to be bad for users who formpost
data that is provided with users who then can guess how the boundary
string will look like and then they can forge a different formpost part
and trick the receiver.

My advice to such implementors is (still even after this change) to not
rely on the boundary strings being cryptographically strong. Fix your
code and logic to not depend on them that much!

I moved the Curl_rand() function into the sslgen.c source file now to be
able to take advantage of the SSL library's random function if it
provides one. If not, try to use the RANDOM_FILE for seeding and as a
last resort keep the old logic, just modified to also add microseconds
which makes it harder to properly guess the exact seed.

The formboundary() function in formdata.c is now using 64 bit entropy
for the boundary and therefore the string of dashes was reduced by 4
letters and there are 16 hex digits following it. The total length is
thus still the same.

Bug: http://curl.haxx.se/bug/view.cgi?id=1251
Reported-by: "Floris"

This commit renames lib/setup.h to lib/curl_setup.h and
renames lib/setup_once.h to lib/curl_setup_once.h.

Removes the need and usage of a header inclusion guard foreign
to libcurl. [1]

Removes the need and presence of an alarming notice we carried
in old setup_once.h [2]

----------------------------------------

1 - lib/setup_once.h used __SETUP_ONCE_H macro as header inclusion guard
    up to commit ec691ca3 which changed this to HEADER_CURL_SETUP_ONCE_H,
    this single inclusion guard is enough to ensure that inclusion of
    lib/setup_once.h done from lib/setup.h is only done once.

    Additionally lib/setup.h has always used __SETUP_ONCE_H macro to
    protect inclusion of setup_once.h even after commit ec691ca3, this
    was to avoid a circular header inclusion triggered when building a
    c-ares enabled version with c-ares sources available which also has
    a setup_once.h header. Commit ec691ca3 exposes the real nature of
    __SETUP_ONCE_H usage in lib/setup.h, it is a header inclusion guard
    foreign to libcurl belonging to c-ares's setup_once.h

    The renaming this commit does, fixes the circular header inclusion,
    and as such removes the need and usage of a header inclusion guard
    foreign to libcurl. Macro __SETUP_ONCE_H no longer used in libcurl.

2 - Due to the circular interdependency of old lib/setup_once.h and the
    c-ares setup_once.h header, old file lib/setup_once.h has carried
    back from 2006 up to now days an alarming and prominent notice about
    the need of keeping libcurl's and c-ares's setup_once.h in sync.

    Given that this commit fixes the circular interdependency, the need
    and presence of mentioned notice is removed.

    All mentioned interdependencies come back from now old days when
    the c-ares project lived inside a curl subdirectory. This commit
    removes last traces of such fact.

This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:

  f871de00... build: make use of 76 lib/*.h renamed files
  ffd8e127... build: rename 76 lib/*.h files

This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:

  c087374c... curl_setup.h: remove redundant include guard

This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:

  13606bbf... build: make use of 93 lib/*.c renamed files
  5b6e7927... build: rename 93 lib/*.c files
  7d83dfff... build: commit 13606bbf follow-up 1

Start of related discussion thread:

  http://curl.haxx.se/mail/lib-2013-01/0012.html

Asking for confirmation on pushing this revertion commit:

  http://curl.haxx.se/mail/lib-2013-01/0048.html

Confirmation summary:

  http://curl.haxx.se/mail/lib-2013-01/0079.html

NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.

  lib/curl_imap.h
  lib/curl_smtp.h

76 private header files renamed to use our standard naming scheme.

This commit only does the file renaming.

----------------------------------------

  renamed:    amigaos.h -> curl_amigaos.h
  renamed:    arpa_telnet.h -> curl_arpa_telnet.h
  renamed:    asyn.h -> curl_asyn.h
  renamed:    axtls.h -> curl_axtls.h
  renamed:    bundles.h -> curl_bundles.h
  renamed:    conncache.h -> curl_conncache.h
  renamed:    connect.h -> curl_connect.h
  renamed:    content_encoding.h -> curl_content_encoding.h
  renamed:    cookie.h -> curl_cookie.h
  renamed:    cyassl.h -> curl_cyassl.h
  renamed:    dict.h -> curl_dict.h
  renamed:    easyif.h -> curl_easyif.h
  renamed:    escape.h -> curl_escape.h
  renamed:    file.h -> curl_file.h
  renamed:    fileinfo.h -> curl_fileinfo.h
  renamed:    formdata.h -> curl_formdata.h
  renamed:    ftp.h -> curl_ftp.h
  renamed:    ftplistparser.h -> curl_ftplistparser.h
  renamed:    getinfo.h -> curl_getinfo.h
  renamed:    gopher.h -> curl_gopher.h
  renamed:    gtls.h -> curl_gtls.h
  renamed:    hash.h -> curl_hash.h
  renamed:    hostcheck.h -> curl_hostcheck.h
  renamed:    hostip.h -> curl_hostip.h
  renamed:    http.h -> curl_http.h
  renamed:    http_chunks.h -> curl_http_chunks.h
  renamed:    http_digest.h -> curl_http_digest.h
  renamed:    http_negotiate.h -> curl_http_negotiate.h
  renamed:    http_proxy.h -> curl_http_proxy.h
  renamed:    if2ip.h -> curl_if2ip.h
  renamed:    imap.h -> curl_imap.h
  renamed:    inet_ntop.h -> curl_inet_ntop.h
  renamed:    inet_pton.h -> curl_inet_pton.h
  renamed:    krb4.h -> curl_krb4.h
  renamed:    llist.h -> curl_llist.h
  renamed:    memdebug.h -> curl_memdebug.h
  renamed:    multiif.h -> curl_multiif.h
  renamed:    netrc.h -> curl_netrc.h
  renamed:    non-ascii.h -> curl_non-ascii.h
  renamed:    nonblock.h -> curl_nonblock.h
  renamed:    nssg.h -> curl_nssg.h
  renamed:    parsedate.h -> curl_parsedate.h
  renamed:    pingpong.h -> curl_pingpong.h
  renamed:    polarssl.h -> curl_polarssl.h
  renamed:    pop3.h -> curl_pop3.h
  renamed:    progress.h -> curl_progress.h
  renamed:    qssl.h -> curl_qssl.h
  renamed:    rawstr.h -> curl_rawstr.h
  renamed:    rtsp.h -> curl_rtsp.h
  renamed:    select.h -> curl_select.h
  renamed:    sendf.h -> curl_sendf.h
  renamed:    setup.h -> curl_setup.h
  renamed:    setup_once.h -> curl_setup_once.h
  renamed:    share.h -> curl_share.h
  renamed:    slist.h -> curl_slist.h
  renamed:    smtp.h -> curl_smtp.h
  renamed:    sockaddr.h -> curl_sockaddr.h
  renamed:    socks.h -> curl_socks.h
  renamed:    speedcheck.h -> curl_speedcheck.h
  renamed:    splay.h -> curl_splay.h
  renamed:    ssh.h -> curl_ssh.h
  renamed:    sslgen.h -> curl_sslgen.h
  renamed:    ssluse.h -> curl_ssluse.h
  renamed:    strdup.h -> curl_strdup.h
  renamed:    strequal.h -> curl_strequal.h
  renamed:    strerror.h -> curl_strerror.h
  renamed:    strtok.h -> curl_strtok.h
  renamed:    strtoofft.h -> curl_strtoofft.h
  renamed:    telnet.h -> curl_telnet.h
  renamed:    tftp.h -> curl_tftp.h
  renamed:    timeval.h -> curl_timeval.h
  renamed:    transfer.h -> curl_transfer.h
  renamed:    url.h -> curl_url.h
  renamed:    urldata.h -> curl_urldata.h
  renamed:    warnless.h -> curl_warnless.h
  renamed:    wildcard.h -> curl_wildcard.h

----------------------------------------

76 private header files renamed to use our standard naming scheme.

This change affects 322 files in libcurl's source tree.

curl_ntlm_msgs.c would previously use an #ifdef maze and direct
SSL-library calls instead of using the SSL layer we have for this
purpose.

With locking, plus test, plus documentation

Stop the abuse of CURLE_FAILED_INIT as return code for things not being
init related by introducing two new return codes:

CURLE_NOT_BUILT_IN and CURLE_UNKNOWN_OPTION

CURLE_NOT_BUILT_IN replaces return code 4 that has been obsoleted for
several years. It is used for returning error when something is
attempted to be used but the feature/option was not enabled or
explictitly disabled at build-time. Getting this error mostly means that
libcurl needs to be rebuilt.

CURLE_FAILED_INIT is now saved and used strictly for init
failures. Getting this problem means something went seriously wrong,
like a resource shortage or similar.

CURLE_UNKNOWN_OPTION is the option formerly known as
CURLE_UNKNOWN_TELNET_OPTION (and the old name is still present,
separately defined to be removed in a very distant future). This error
code is meant to be used to return when an option is given to libcurl
that isn't known. This problem would mostly indicate a problem in the
program that uses libcurl.

The non-blocking connect improvement for IMAP showed that we didn't
properly define the Curl_ssl_connect_nonblocking function for non-SSL
builds.

Reported by: Tor Arntsen

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.

Signed-off-by: Ben Greear <greearb@candelatech.com>

  (http://curl.haxx.se/bug/view.cgi?id=2786255) with a patch, identifying how
  libcurl did not deal with SSL session ids properly if the server rejected a
  re-use of one. Starting now, it will forget the rejected one and remember
  the new. This change was for OpenSSL only, it is likely that other SSL lib
  code needs similar fixes.

  (http://curl.haxx.se/bug/view.cgi?id=2255627) which pointed out that a
  program using libcurl's multi interface to download a HTTPS page with a
  libcurl built powered by OpenSSL, would easily get silly and instead hand
  over SSL details as data instead of the actual HTTP headers and body. This
  happened because libcurl would consider the connection handshake done too
  early. This problem was introduced at September 22nd 2008 with my fix of the
  bug #2107377

  The correct fix is now instead done within the GnuTLS-handling code, as both
  the OpenSSL and the NSS code already deal with this situation in similar
  fashion. I added test case 560 in an attempt to verify this fix, but
  unfortunately it didn't trigger it even before this fix!

  enabling this feature with CURLOPT_CERTINFO for a request using SSL (HTTPS
  or FTPS), libcurl will gather lots of server certificate info and that info
  can then get extracted by a client after the request has completed with
  curl_easy_getinfo()'s CURLINFO_CERTINFO option. Linus Nielsen Feltzing
  helped me test and smoothen out this feature.

  Unfortunately, this feature currently only works with libcurl built to use
  OpenSSL.

  This feature was sponsored by networking4all.com - thanks!

  libraries are supported. Starting now, each underlying SSL library support
  code does a set of defines for the 16 functions the generic layer (sslgen.c)
  uses (all these new function defines use the prefix "curlssl_"). This
  greatly simplified the generic layer in readability by involving much less
  #ifdefs and other preprocessor stuff and should make it easier for people to
  make libcurl work with new SSL libraries.

  Hopefully I can later on document these 16 functions somewhat as well.

  I also made most of the internal SSL-dependent functions (using Curl_ssl_
  prefix) #defined to nothing when no SSL support is requested - previously
  they would unnecessarily call mostly empty functions.

  of tetetest's patch for curl_easy_send()

of a socket after it has been closed, when the FTP-SSL data connection is taken
down.

  curl that uses the new CURLOPT_FTP_SSL_CCC option in libcurl. If enabled, it
  will make libcurl shutdown SSL/TLS after the authentication is done on a
  FTP-SSL operation.

They all now return ssize_t to Curl_write().

Unfortunately, Curl_read() is in a sorrier state but it too would benefit from
a similar cleanup.

checks on the to-be-returned socket to make sure it truly seems to be alive
and well. For SSL connection it (only) uses OpenSSL functions.

(when using OpenSSL).

internally, with code provided by sslgen.c. All SSL-layer-specific code is
then written in ssluse.c (for OpenSSL) and gtls.c (for GnuTLS).

As far as possible, internals should not need to know what SSL layer that is
in use. Building with GnuTLS currently makes two test cases fail.

TODO.gnutls contains a few known outstanding issues for the GnuTLS support.

GnuTLS support is enabled with configure --with-gnutls