- add session with destructor callback
- remove vtls `session_free` method
- let `Curl_ssl_addsessionid()` take ownership
of session object, freeing it also on failures
- change tls backend use
- test_17, add tests for SSL session resumption
Closes#13386
- Use data->multi and not data->multi_easy to refer to the active multi.
The easy handle's active multi is always data->multi.
This is a follow up to 757dfdf which changed curl so that an easy handle
used with the easy interface and then multi interface cannot have two
different multi handles associated with it at the same time
(data->multi_easy from the easy interface and data->multi from the multi
interface).
Closes https://github.com/curl/curl/pull/12665
Reduced size of dynamically_allocated_data structure.
Reduced number of stored values in enum dupstring and enum dupblob. This
affects the reduced array placed in the UserDefined structure.
Closes#13188
- Treat TLS connection close (either due to a close_notify from the
server or just closed due to receiving 0) as pending data.
This is because in some cases schannel_recv knows the connection is
closed but has to return actual pending data so it can't return 0 or an
error to indicate no more data. In this case schannel_recv must be
called again, which only happens if readwrite_data sees that there is
still pending data.
Prior to this change if the total size of the body that libcurl expected
to receive from the server was unknown then it was possible under some
network conditions that libcurl would hang waiting to receive more data,
when in fact a close_notify alert indicating no more data would be sent
was already processed.
Fixes https://github.com/curl/curl/issues/12894
Closes https://github.com/curl/curl/pull/12910
```
lib/vtls/schannel.c:1201:22: warning: conversion to 'unsigned int' from 'int' may change the sign of the result [-Warith-conversion]
1201 | *extension_len = *list_len +
| ^
```
Closes#12616
https://best.openssf.org/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C++.html
as of 2023-11-29 [1].
Enable new recommended warnings (except `-Wsign-conversion`):
- enable `-Wformat=2` for clang (in both cmake and autotools).
- add `CURL_PRINTF()` internal attribute and mark functions accepting
printf arguments with it. This is a copy of existing
`CURL_TEMP_PRINTF()` but using `__printf__` to make it compatible
with redefinting the `printf` symbol:
https://gcc.gnu.org/onlinedocs/gcc-3.0.4/gcc_5.html#SEC94
- fix `CURL_PRINTF()` and existing `CURL_TEMP_PRINTF()` for
mingw-w64 and enable it on this platform.
- enable `-Wimplicit-fallthrough`.
- enable `-Wtrampolines`.
- add `-Wsign-conversion` commented with a FIXME.
- cmake: enable `-pedantic-errors` the way we do it with autotools.
Follow-up to d5c0351055#2747
- lib/curl_trc.h: use `CURL_FORMAT()`, this also fixes it to enable format
checks. Previously it was always disabled due to the internal `printf`
macro.
Fix them:
- fix bug where an `set_ipv6_v6only()` call was missed in builds with
`--disable-verbose` / `CURL_DISABLE_VERBOSE_STRINGS=ON`.
- add internal `FALLTHROUGH()` macro.
- replace obsolete fall-through comments with `FALLTHROUGH()`.
- fix fallthrough markups: Delete redundant ones (showing up as
warnings in most cases). Add missing ones. Fix indentation.
- silence `-Wformat-nonliteral` warnings with llvm/clang.
- fix one `-Wformat-nonliteral` warning.
- fix new `-Wformat` and `-Wformat-security` warnings.
- fix `CURL_FORMAT_SOCKET_T` value for mingw-w64. Also move its
definition to `lib/curl_setup.h` allowing use in `tests/server`.
- lib: fix two wrongly passed string arguments in log outputs.
Co-authored-by: Jay Satiro
- fix new `-Wformat` warnings on mingw-w64.
[1] 56c0fde389/docs/Compiler-Hardening-Guides/Compiler-Options-Hardening-Guide-for-C-and-C%2B%2B.mdCloses#12489
- add `struct ssl_peer` to keep hostname, dispname and sni
for a filter
- allocate `sni` for use in VTLS backend
- eliminate `Curl_ssl_snihost()` and its use of the download buffer
- use ssl_peer in SSL and QUIC filters
Closes#12349
Connection filter had a `get_select_socks()` method, inspired by the
various `getsocks` functions involved during the lifetime of a
transfer. These, depending on transfer state (CONNECT/DO/DONE/ etc.),
return sockets to monitor and flag if this shall be done for POLLIN
and/or POLLOUT.
Due to this design, sockets and flags could only be added, not
removed. This led to problems in filters like HTTP/2 where flow control
prohibits the sending of data until the peer increases the flow
window. The general transfer loop wants to write, adds POLLOUT, the
socket is writeable but no data can be written.
This leads to cpu busy loops. To prevent that, HTTP/2 did set the
`SEND_HOLD` flag of such a blocked transfer, so the transfer loop cedes
further attempts. This works if only one such filter is involved. If a
HTTP/2 transfer goes through a HTTP/2 proxy, two filters are
setting/clearing this flag and may step on each other's toes.
Connection filters `get_select_socks()` is replaced by
`adjust_pollset()`. They get passed a `struct easy_pollset` that keeps
up to `MAX_SOCKSPEREASYHANDLE` sockets and their `POLLIN|POLLOUT`
flags. This struct is initialized in `multi_getsock()` by calling the
various `getsocks()` implementations based on transfer state, as before.
After protocol handlers/transfer loop have set the sockets and flags
they want, the `easy_pollset` is *always* passed to the filters. Filters
"higher" in the chain are called first, starting at the first
not-yet-connection one. Each filter may add sockets and/or change
flags. When all flags are removed, the socket itself is removed from the
pollset.
Example:
* transfer wants to send, adds POLLOUT
* http/2 filter has a flow control block, removes POLLOUT and adds
POLLIN (it is waiting on a WINDOW_UPDATE from the server)
* TLS filter is connected and changes nothing
* h2-proxy filter also has a flow control block on its tunnel stream,
removes POLLOUT and adds POLLIN also.
* socket filter is connected and changes nothing
* The resulting pollset is then mixed together with all other transfers
and their pollsets, just as before.
Use of `SEND_HOLD` is no longer necessary in the filters.
All filters are adapted for the changed method. The handling in
`multi.c` has been adjusted, but its state handling the the protocol
handlers' `getsocks` method are untouched.
The most affected filters are http/2, ngtcp2, quiche and h2-proxy. TLS
filters needed to be adjusted for the connecting handshake read/write
handling.
No noticeable difference in performance was detected in local scorecard
runs.
Closes#11833
- Use CERT_CONTEXT's pbCertEncoded to determine chain order.
CERT_CONTEXT from SECPKG_ATTR_REMOTE_CERT_CONTEXT contains
end-entity/server certificate in pbCertEncoded. We can use this pointer
to determine the order of certificates when enumerating hCertStore using
CertEnumCertificatesInStore.
This change is to help ensure that the ordering of the certificate chain
requested by the user via CURLINFO_CERTINFO has the same ordering on all
versions of Windows.
Prior to this change Schannel certificate order was reversed in 8986df80
but that was later reverted in f540a39b when it was discovered that
Windows 11 22H2 does the reversal on its own.
Ref: https://github.com/curl/curl/issues/9706
Closes https://github.com/curl/curl/pull/11632
- If the user set a legacy algorithm list (CURLOPT_SSL_CIPHER_LIST) then
use the SCHANNEL_CRED legacy structure to pass the list to Schannel.
- If the user set both a legacy algorithm list and a TLS 1.3 cipher list
then abort.
Although MS doesn't document it, Schannel will not negotiate TLS 1.3
when SCHANNEL_CRED is used. That means setting a legacy algorithm list
limits the user to earlier versions of TLS.
Prior to this change, since 8beff435 (precedes 7.85.0), libcurl would
ignore legacy algorithms in Windows 10 1809 and later.
Reported-by: zhihaoy@users.noreply.github.com
Fixes https://github.com/curl/curl/pull/10741
Closes https://github.com/curl/curl/pull/10746
This reverts commit 8986df802d.
Windows does not guarantee a particular certificate ordering, even
though TLS may have its own ordering/relationship guarantees. Recent
versions of Windows 11 reversed the ordering of ceritifcates returned by
CertEnumCertificatesInStore, therefore this commit no longer works as
initially intended. libcurl makes no guarantees about certificate
ordering if the operating system can't.
Ref: https://github.com/curl/curl/issues/9706
Closes https://github.com/curl/curl/pull/11536
Aka "jumbo" or "amalgamation" builds. It means to compile all sources
per target as a single C source. This is experimental.
You can enable it by passing `-DCMAKE_UNITY_BUILD=ON` to cmake.
It requires CMake 3.16 or newer.
It makes builds (much) faster, allows for better optimizations and tends
to promote less ambiguous code.
Also add a new AppVeyor CI job and convert an existing one to use
"unity" mode (one MSVC, one MinGW), and enable it for one macOS CI job.
Fix related issues:
- add missing include guard to `easy_lock.h`.
- rename static variables and functions (and a macro) with names reused
across sources, or shadowed by local variables.
- add an `#undef` after use.
- add a missing `#undef` before use.
- move internal definitions from `ftp.h` to `ftp.c`.
- `curl_memory.h` fixes to make it work when included repeatedly.
- stop building/linking curlx bits twice for a static-mode curl tool.
These caused doubly defined symbols in unity builds.
- silence missing extern declarations compiler warning for ` _CRT_glob`.
- fix extern declarations for `tool_freq` and `tool_isVistaOrGreater`.
- fix colliding static symbols in debug mode: `debugtime()` and
`statename`.
- rename `ssl_backend_data` structure to unique names for each
TLS-backend, along with the `ssl_connect_data` struct member
referencing them. This required adding casts for each access.
- add workaround for missing `[P]UNICODE_STRING` types in certain Windows
builds when compiling `lib/ldap.c`. To support "unity" builds, we had
to enable `SCHANNEL_USE_BLACKLISTS` for Schannel (a Windows
`schannel.h` option) _globally_. This caused an indirect inclusion of
Windows `schannel.h` from `ldap.c` via `winldap.h` to have it enabled
as well. This requires `[P]UNICODE_STRING` types, which is apperantly
not defined automatically (as seen with both MSVS and mingw-w64).
This patch includes `<subauth.h>` to fix it.
Ref: https://github.com/curl/curl/runs/13987772013
Ref: https://dev.azure.com/daniel0244/curl/_build/results?buildId=15827&view=logs&jobId=2c9f582d-e278-56b6-4354-f38a4d851906&j=2c9f582d-e278-56b6-4354-f38a4d851906&t=90509b00-34fa-5a81-35d7-5ed9569d331c
- tweak unity builds to compile `lib/memdebug.c` separately in memory
trace builds to avoid PP confusion.
- force-disable unity for test programs.
- do not compile and link libcurl sources to libtests _twice_ when libcurl
is built in static mode.
KNOWN ISSUES:
- running tests with unity builds may fail in cases.
- some build configurations/env may not compile in unity mode. E.g.:
https://ci.appveyor.com/project/curlorg/curl/builds/47230972/job/51wfesgnfuauwl8q#L250
Ref: https://github.com/libssh2/libssh2/issues/1034
Ref: https://cmake.org/cmake/help/latest/prop_tgt/UNITY_BUILD.html
Ref: https://en.wikipedia.org/wiki/Unity_buildCloses#11095
Out of 415 labels throughout the code base, 86 of those labels were
not at the start of the line. Which means labels always at the start of
the line is the favoured style overall with 329 instances.
Out of the 86 labels not at the start of the line:
* 75 were indented with the same indentation level of the following line
* 8 were indented with exactly one space
* 2 were indented with one fewer indentation level then the following
line
* 1 was indented with the indentation level of the following line minus
three space (probably unintentional)
Co-Authored-By: Viktor Szakats
Closes#11134
New cfilter HTTP-CONNECT for h3/h2/http1.1 eyeballing.
- filter is installed when `--http3` in the tool is used (or
the equivalent CURLOPT_ done in the library)
- starts a QUIC/HTTP/3 connect right away. Should that not
succeed after 100ms (subject to change), a parallel attempt
is started for HTTP/2 and HTTP/1.1 via TCP
- both attempts are subject to IPv6/IPv4 eyeballing, same
as happens for other connections
- tie timeout to the ip-version HAPPY_EYEBALLS_TIMEOUT
- use a `soft` timeout at half the value. When the soft timeout
expires, the HTTPS-CONNECT filter checks if the QUIC filter
has received any data from the server. If not, it will start
the HTTP/2 attempt.
HTTP/3(ngtcp2) improvements.
- setting call_data in all cfilter calls similar to http/2 and vtls filters
for use in callback where no stream data is available.
- returning CURLE_PARTIAL_FILE for prematurely terminated transfers
- enabling pytest test_05 for h3
- shifting functionality to "connect" UDP sockets from ngtcp2
implementation into the udp socket cfilter. Because unconnected
UDP sockets are weird. For example they error when adding to a
pollset.
HTTP/3(quiche) improvements.
- fixed upload bug in quiche implementation, now passes 251 and pytest
- error codes on stream RESET
- improved debug logs
- handling of DRAIN during connect
- limiting pending event queue
HTTP/2 cfilter improvements.
- use LOG_CF macros for dynamic logging in debug build
- fix CURLcode on RST streams to be CURLE_PARTIAL_FILE
- enable pytest test_05 for h2
- fix upload pytests and improve parallel transfer performance.
GOAWAY handling for ngtcp2/quiche
- during connect, when the remote server refuses to accept new connections
and closes immediately (so the local conn goes into DRAIN phase), the
connection is torn down and a another attempt is made after a short grace
period.
This is the behaviour observed with nghttpx when we tell it to shut
down gracefully. Tested in pytest test_03_02.
TLS improvements
- ALPN selection for SSL/SSL-PROXY filters in one vtls set of functions, replaces
copy of logic in all tls backends.
- standardized the infof logging of offered ALPNs
- ALPN negotiated: have common function for all backends that sets alpn proprty
and connection related things based on the negotiated protocol (or lack thereof).
- new tests/tests-httpd/scorecard.py for testing h3/h2 protocol implementation.
Invoke:
python3 tests/tests-httpd/scorecard.py --help
for usage.
Improvements on gathering connect statistics and socket access.
- new CF_CTRL_CONN_REPORT_STATS cfilter control for having cfilters
report connection statistics. This is triggered when the connection
has completely connected.
- new void Curl_pgrsTimeWas(..) method to report a timer update with
a timestamp of when it happend. This allows for updating timers
"later", e.g. a connect statistic after full connectivity has been
reached.
- in case of HTTP eyeballing, the previous changes will update
statistics only from the filter chain that "won" the eyeballing.
- new cfilter query CF_QUERY_SOCKET for retrieving the socket used
by a filter chain.
Added methods Curl_conn_cf_get_socket() and Curl_conn_get_socket()
for convenient use of this query.
- Change VTLS backend to query their sub-filters for the socket when
checks during the handshake are made.
HTTP/3 documentation on how https eyeballing works.
TLS improvements
- ALPN selection for SSL/SSL-PROXY filters in one vtls set of functions, replaces
copy of logic in all tls backends.
- standardized the infof logging of offered ALPNs
- ALPN negotiated: have common function for all backends that sets alpn proprty
and connection related things based on the negotiated protocol (or lack thereof).
Scorecard with Caddy.
- configure can be run with `--with-test-caddy=path` to specify which caddy to use for testing
- tests/tests-httpd/scorecard.py now measures download speeds with caddy
pytest improvements
- adding Makfile to clean gen dir
- adding nghttpx rundir creation on start
- checking httpd version 2.4.55 for test_05 cases where it is needed. Skipping with message if too old.
- catch exception when checking for caddy existance on system.
Closes#10349
- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING
checksrc is updated to allow non-year using copyright statements
Closes#10205
- almost all backend calls pass the Curl_cfilter intance instead of
connectdata+sockindex
- ssl_connect_data is remove from struct connectdata and made internal
to vtls
- ssl_connect_data is allocated in the added filter, kept at cf->ctx
- added function to let a ssl filter access its ssl_primary_config and
ssl_config_data this selects the propert subfields in conn and data,
for filters added as plain or proxy
- adjusted all backends to use the changed api
- adjusted all backends to access config data via the exposed
functions, no longer using conn or data directly
cfilter renames for clear purpose:
- methods `Curl_conn_*(data, conn, sockindex)` work on the complete
filter chain at `sockindex` and connection `conn`.
- methods `Curl_cf_*(cf, ...)` work on a specific Curl_cfilter
instance.
- methods `Curl_conn_cf()` work on/with filter instances at a
connection.
- rebased and resolved some naming conflicts
- hostname validation (und session lookup) on SECONDARY use the same
name as on FIRST (again).
new debug macros and removing connectdata from function signatures where not
needed.
adapting schannel for new Curl_read_plain paramter.
Closes#9919
Prior to this change Curl_read_plain would attempt to read the
socket directly. On Windows that's a problem because recv data may be
cached by libcurl and that data is only drained using Curl_recv_plain.
Rather than rewrite Curl_read_plain to handle cached recv data, I
changed it to wrap Curl_recv_plain, in much the same way that
Curl_write_plain already wraps Curl_send_plain.
Curl_read_plain -> Curl_recv_plain
Curl_write_plain -> Curl_send_plain
This fixes a bug in the schannel backend where decryption of arbitrary
TLS records fails because cached recv data is never drained. We send
data (TLS records formed by Schannel) using Curl_write_plain, which
calls Curl_send_plain, and that may do a recv-before-send
("pre-receive") to cache received data. The code calls Curl_read_plain
to read data (TLS records from the server), which prior to this change
did not call Curl_recv_plain and therefore cached recv data wasn't
retrieved, resulting in malformed TLS records and decryption failure
(SEC_E_DECRYPT_FAILURE).
The bug has only been observed during Schannel TLS 1.3 handshakes. Refer
to the issue and PR for more information.
--
This is take 2 of the original fix. It preserves the original behavior
of Curl_read_plain to write 0 to the bytes read parameter on error,
since apparently some callers expect that (SOCKS tests were hanging).
The original fix which landed in 12e1def5 and was later reverted in
18383fbf failed to work properly because it did not do that.
Also, it changes Curl_write_plain the same way to complement
Curl_read_plain, and it changes Curl_send_plain to return -1 instead of
0 on CURLE_AGAIN to complement Curl_recv_plain.
Behavior on error with these changes:
Curl_recv_plain returns -1 and *code receives error code.
Curl_send_plain returns -1 and *code receives error code.
Curl_read_plain returns error code and *n (bytes read) receives 0.
Curl_write_plain returns error code and *written receives 0.
--
Ref: https://github.com/curl/curl/issues/9431#issuecomment-1312420361
Assisted-by: Joel Depooter
Reported-by: Egor Pugin
Fixes https://github.com/curl/curl/issues/9431
Closes https://github.com/curl/curl/pull/9949
Prior to this change Curl_read_plain would attempt to read the
socket directly. On Windows that's a problem because recv data may be
cached by libcurl and that data is only drained using Curl_recv_plain.
Rather than rewrite Curl_read_plain to handle cached recv data, I
changed it to wrap Curl_recv_plain, in much the same way that
Curl_write_plain already wraps Curl_send_plain.
Curl_read_plain -> Curl_recv_plain
Curl_write_plain -> Curl_send_plain
This fixes a bug in the schannel backend where decryption of arbitrary
TLS records fails because cached recv data is never drained. We send
data (TLS records formed by Schannel) using Curl_write_plain, which
calls Curl_send_plain, and that may do a recv-before-send
("pre-receive") to cache received data. The code calls Curl_read_plain
to read data (TLS records from the server), which prior to this change
did not call Curl_recv_plain and therefore cached recv data wasn't
retrieved, resulting in malformed TLS records and decryption failure
(SEC_E_DECRYPT_FAILURE).
The bug has only been observed during Schannel TLS 1.3 handshakes. Refer
to the issue and PR for more information.
Ref: https://github.com/curl/curl/issues/9431#issuecomment-1312420361
Assisted-by: Joel Depooter
Reported-by: Egor Pugin
Fixes https://github.com/curl/curl/issues/9431
Closes https://github.com/curl/curl/pull/9904
- general construct/destroy in connectdata
- default implementations of callback functions
- connect: cfilters for connect and accept
- socks: cfilter for socks proxying
- http_proxy: cfilter for http proxy tunneling
- vtls: cfilters for primary and proxy ssl
- change in general handling of data/conn
- Curl_cfilter_setup() sets up filter chain based on data settings,
if none are installed by the protocol handler setup
- Curl_cfilter_connect() boot straps filters into `connected` status,
used by handlers and multi to reach further stages
- Curl_cfilter_is_connected() to check if a conn is connected,
e.g. all filters have done their work
- Curl_cfilter_get_select_socks() gets the sockets and READ/WRITE
indicators for multi select to work
- Curl_cfilter_data_pending() asks filters if the have incoming
data pending for recv
- Curl_cfilter_recv()/Curl_cfilter_send are the general callbacks
installed in conn->recv/conn->send for io handling
- Curl_cfilter_attach_data()/Curl_cfilter_detach_data() inform filters
and addition/removal of a `data` from their connection
- adding vtl functions to prevent use of Curl_ssl globals directly
in other parts of the code.
Reviewed-by: Daniel Stenberg
Closes#9855
Even though `PICKY_COMPILER=ON` is the default, warnings were not
enabled when using llvm/clang, because `CMAKE_COMPILER_IS_CLANG` was
always false (in my tests at least).
This is the single use of this variable in curl, and in a different
place we already use `CMAKE_C_COMPILER_ID MATCHES "Clang"`, which works
as expected, so change the condition to use that instead.
Also fix the warnings uncovered by the above:
- lib: add casts to silence clang warnings
- schannel: add casts to silence clang warnings in ALPN code
Assuming the code is correct, solve the warnings with a cast.
This particular build case isn't CI tested.
There is a chance the warning is relevant for some platforms, perhaps
Windows 32-bit ARM7.
Closes#9783
These function pointers will have been set when the initial TLS
handshake was completed. If they are unchanged, there is no need to set
them again. If they have been changed, as is the case with HTTP/2, we
don't want to override that change. That would result in the
http22_recv/send functions being completely bypassed.
Prior to this change a connection that uses Schannel with HTTP/2 would
fail on renegotiation with error "Received HTTP/0.9 when not allowed".
Fixes https://github.com/curl/curl/issues/9451
Closes https://github.com/curl/curl/pull/9756
By default, the PFXImportCertStore API persists the key in the user's
key store (as though the certificate was being imported for permanent,
ongoing use.)
The documentation specifies that keys that are not to be persisted
should be imported with the flag PKCS12_NO_PERSIST_KEY.
NOTE: this flag is only supported on versions of Windows newer than XP
and Server 2003.
--
This is take 2 of the original fix. It extends the lifetime of the
client certificate store to that of the credential handle. The original
fix which landed in 70d010d and was later reverted in aec8d30 failed to
work properly because it did not do that.
Minor changes were made to the schannel credential context to support
closing the client certificate store handle at the end of an SSL session.
--
Reported-by: ShadowZzj@users.noreply.github.com
Fixes https://github.com/curl/curl/issues/9300
Supersedes https://github.com/curl/curl/pull/9363
Closes https://github.com/curl/curl/pull/9460
Next Protocol Negotiation is a TLS extension that was created and used
for agreeing to use the SPDY protocol (the precursor to HTTP/2) for
HTTPS. In the early days of HTTP/2, before the spec was finalized and
shipped, the protocol could be enabled using this extension with some
servers.
curl supports the NPN extension with some TLS backends since then, with
a command line option `--npn` and in libcurl with
`CURLOPT_SSL_ENABLE_NPN`.
HTTP/2 proper is made to use the ALPN (Application-Layer Protocol
Negotiation) extension and the NPN extension has no purposes
anymore. The HTTP/2 spec was published in May 2015.
Today, use of NPN in the wild should be extremely rare and most likely
totally extinct. Chrome removed NPN support in Chrome 51, shipped in
June 2016. Removed in Firefox 53, April 2017.
Closes#9307
By default, the PFXImportCertStore API persists the key in the user's
key store (as though the certificate was being imported for permanent,
ongoing use.)
The documentation specifies that keys that are not to be persisted
should be imported with the flag `PKCS12_NO_PERSIST_KEY`.
NOTE: this flag is only supported on versions of Windows newer than XP
and Server 2003.
Fixes#9300Closes#9363
- Support TLS 1.3 as the default max TLS version for Windows Server 2022
and Windows 11.
- Support specifying TLS 1.3 ciphers via existing option
CURLOPT_TLS13_CIPHERS (tool: --tls13-ciphers).
Closes https://github.com/curl/curl/pull/8419
- Use the Windows API to seed the fallback random generator.
This ensures to always have a random seed, even when libcurl is built
with a vtls backend lacking a random generator API, such as rustls
(experimental), GSKit and certain mbedTLS builds, or, when libcurl is
built without a TLS backend. We reuse the Windows-specific random
function from the Schannel backend.
- Implement support for `BCryptGenRandom()` [1] on Windows, as a
replacement for the deprecated `CryptGenRandom()` [2] function.
It is used as the secure random generator for Schannel, and also to
provide entropy for libcurl's fallback random generator. The new
function is supported on Vista and newer via its `bcrypt.dll`. It is
used automatically when building for supported versions. It also works
in UWP apps (the old function did not).
- Clear entropy buffer before calling the Windows random generator.
This avoids using arbitrary application memory as entropy (with
`CryptGenRandom()`) and makes sure to return in a predictable state
when an API call fails.
[1] https://docs.microsoft.com/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom
[2] https://docs.microsoft.com/windows/win32/api/wincrypt/nf-wincrypt-cryptgenrandomCloses#9027
Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the file
`.reuse/dep5`.
This commit also adds a Github workflow to check pull requests and adapts
copyright.pl to the changes.
Closes#8869
