... as the code style mandates.

... not only HTTP uses this now.

Closes #1875

CA path processing was implemented when mbedtls.c was added to libcurl
in fe7590f7, but it was never enabled.

Bug: https://github.com/curl/curl/issues/1877


Reported-by:  <SBKarr@users.noreply.github.com>

If the default write callback is used and no destination has been set, a
NULL pointer would be passed to fwrite()'s 4th argument.

OSS-fuzz bug https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=3327
(not publicly open yet)

Detected by OSS-fuzz
Closes #1874

`conn->connect_state` is NULL when doing a regular non-CONNECT request
over the proxy and should therefor be considered complete at once.

Fixes #1853
Closes #1862
Reported-by: Lawrence Wagerfield

Another mistake in my manual fixups of the largely mechanical
search-and-replace ("connssl->" -> "BACKEND->"), just like the previous
commit concerning HTTPS proxies (and hence not caught during my
earlier testing).

Fixes #1855
Closes #1871

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

In d65e6cc4 (vtls: prepare the SSL backends for encapsulated private
data, 2017-06-21), this developer prepared for a separation of the
private data of the SSL backends from the general connection data.

This conversion was partially automated (search-and-replace) and
partially manual (e.g. proxy_ssl's backend data).

Sadly, there was a crucial error in the manual part, where the wrong
handle was used: rather than connecting ssl[sockindex]' BIO to the
proxy_ssl[sockindex]', we reconnected proxy_ssl[sockindex]. The reason
was an incorrect location to paste "BACKEND->"... d'oh.

Reported by Jay Satiro in https://github.com/curl/curl/issues/1855

.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Ever since 70f1db32

 (vtls: encapsulate SSL backend-specific data,
2017-07-28), the code handling HTTPS proxies was broken because the
pointer to the SSL backend data was not swapped between
conn->ssl[sockindex] and conn->proxy_ssl[sockindex] as intended, but
instead set to NULL (causing segmentation faults).

[jes: provided the commit message, tested and verified the patch]

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

... instead of the prefix-less version since WolfSSL 3.12 now uses an
enum with that name that causes build failures for us.

Fixes #1865
Closes #1867
Reported-by: Gisle Vanem

- The part kind MIMEKIND_FILE and associated code are suppressed.
- Seek data origin offset not used anymore: suppressed.
- MIMEKIND_NAMEDFILE renamed MIMEKIND_FILE; associated fields/functions
  renamed accordingly.
- Curl_getformdata() processes stdin via a callback.

Back in 2008, (and commit 3f3d6ebe) we changed the logic in how we
determine the native type for `curl_off_t`. To really make sure we
didn't break ABI without bumping SONAME, we introduced logic that
attempted to detect that it would use a different size and thus not be
compatible. We also provided a manual switch that allowed users to tell
configure to bump SONAME by force.

Today, we know of no one who ever got a SONAME bump auto-detected and we
don't know of anyone who's using the manual bump feature. The auto-
detection is also no longer working since we introduced defining
curl_off_t in system.h (7.55.0).

Finally, this bumping logic is not present in the cmake build.

Closes #1861

- Do a case-insensitive comparison of CURL_SSL_BACKEND env as well.

- Change Curl_strcasecompare calls to strcasecompare
  (maps to the former but shorter).

Follow-up to c290b8fb.

Bug: https://github.com/curl/curl/commit/c290b8f#commitcomment-24094313

Co-authored-by: Jay Satiro

This is an adaptation of 2 of Peter Wu's SSLKEYLOGFILE implementations.

The first one, written for old OpenSSL versions:
https://git.lekensteyn.nl/peter/wireshark-notes/tree/src/sslkeylog.c

The second one, written for BoringSSL and new OpenSSL versions:
https://github.com/curl/curl/pull/1346

Note the first one is GPL licensed but the author gave permission to
waive that license for libcurl.

As of right now this feature is disabled by default, and does not have
a configure option to enable it. To enable this feature define
ENABLE_SSLKEYLOGFILE when building libcurl and set environment
variable SSLKEYLOGFILE to a pathname that will receive the keys.

And in Wireshark change your preferences to point to that key file:
Edit > Preferences > Protocols > SSL > Master-Secret

Co-authored-by: Peter Wu

Ref: https://github.com/curl/curl/pull/1030
Ref: https://github.com/curl/curl/pull/1346

Closes https://github.com/curl/curl/pull/1866

mime_state is now a typedef.

curl_mime_encoder() is operational and documented.
curl tool -F option is extended with ";encoder=".
curl tool --libcurl option generates calls to curl_mime_encoder().
New encoder tests 648 & 649.
Test 1404 extended with an encoder specification.

... and slightly edited to follow our code style better.

Up2date versions of OpenSSL maintain the default reasonably secure
without breaking compatibility, so it is better not to override the
default by curl.  Suggested at https://bugzilla.redhat.com/1483972

Closes #1846

Added test 1904 to verify.

Reported-by: Lawrence Wagerfield
Fixes #1859
Closes #1860

and some minor whitespace fixes

... not *CACERT_BADFILE as it isn't really because of a bad file.

Bug: https://curl.haxx.se/mail/lib-2017-09/0002.html
Closes #1858

To support telling a string is nul-terminated, symbol CURL_ZERO_TERMINATED
has been introduced.

Documentation updated accordingly.

symbols in versions updated. Added form API symbols deprecation info.

This feature is badly supported in Windows: as a replacement, a caller has
to use curl_mime_data_cb() with fread, fseek and possibly fclose
callbacks to process opened files.

The cli tool and documentation are updated accordingly.

The feature is however kept internally for form API compatibility, with
the known caveats it always had.

As a side effect, stdin size is not determined by the cli tool even if
possible and this results in a chunked transfer encoding. Test 173 is
updated accordingly.

Available in HTTP, SMTP and IMAP.
Deprecates the FORM API.
See CURLOPT_MIMEPOST.
Lib code and associated documentation.

The case keyword may be followed by a constant expression and thus should
allow it to start with an open parenthesis.

Some calls in different modules were setting the data handle to NULL, causing
segmentation faults when using builds that enable character code conversions.

Closes #1849

- Fix handling certificate subjects that are already UTF-8 encoded.

Follow-up to b3b75d17 from two days ago. Since then a copy would be
skipped if the subject was already UTF-8, possibly resulting in a NULL
deref later on.

Ref: https://github.com/curl/curl/issues/1823
Ref: https://github.com/curl/curl/pull/1831

Closes https://github.com/curl/curl/pull/1836

... instead of cyassl, as this is the current name for it.

Closes #1844

Reported-by: Dan Fandrich
Bug: https://curl.haxx.se/mail/lib-2017-08/0121.html
Closes #1843

Closes https://github.com/curl/curl/pull/1840

destroy_async_data() assumes that if the flag "done" is not set yet, the
thread itself will clean up once the request is complete.  But if an
error (generally OOM) occurs before the thread even has a chance to
start, it will never get a chance to clean up and memory will be leaked.
By clearing "done" only just before starting the thread, the correct
cleanup sequence will happen in all cases.

This used to be set in some configurations to EAI_MEMORY which is not a
valid value for errno and caused Curl_strerror to fail an assertion.