OpenSSL version 4.1.0 released

[Tomas Mraz]

OpenSSL version 4.1.0 released
==============================

OpenSSL - The Open Source toolkit for SSL/TLS
https://www.openssl-library.org/

OpenSSL 4.1.0 has now been made available.

The release is available for download at:

   * https://github.com/openssl/openssl/releases

Please download and check this release.
To report a bug, open an issue on GitHub:

* https://github.com/openssl/openssl/issues


Release notes
=============

OpenSSL 4.1.0 is a feature release adding significant new functionality
to OpenSSL.

This release incorporates the following potentially significant or
incompatible
changes:

* Added VC-WIN32-MSVC2013 and VC-WIN64A-MSVC2013 build targets to provide
internal functions for bridging the gaps in C99 standard support
that are present in MSVC 2013.

* Added optimized ML-DSA and ML-KEM NTT operations on ppc64le;
optimized ML-DSA operations on x86_64;
AVX-512-optimized SHAKE x4 operations for ML-DSA on x86_64;
AVX-512 and VAES optimizations for AES-CBC decryption on x86_64.

* Changed tsget utility to use Net::Curl::Easy (from the Net-Curl CPAN
distribution) instead of the abandoned WWW::Curl::Easy. Users who rely
on tsget should install Net::Curl::Easy before upgrading.

* Dropped Windows-on-Itanium (VC-WIN64I) and Windows CE (VC-CE) targets
from Configurations.

* Dropped no-ecdsa and no-ecdh options from Configure, as these options
did not really disable the implementations. Use no-ec to disable
the elliptic curve support.

This release adds the following new features:

* Support for DTLS 1.3 (RFC 9147).
Refer to the ossl-guide-dtlsv13(7) manual page for details.

* Support for RFC 8701 GREASE (Generate Random Extensions And Sustain
Extensibility).

* DTLS support in the SSL listener API.

* Support for IKEV2 KDF.

* Initial support for the Elbrus2000 (e2k) architecture.

Known issues in 4.1.0:

* #32878
When a DTLS 1.3 KeyUpdate is received, all other outstanding
post-handshake records are dropped from the retransmission buffer.
This means post-handshake records still awaiting an ACK (such as a
NewSessionTicket) will no longer be retransmitted if the original
transmission is lost.

* #33277
A permanent receive failure on a DTLS listener can be reported as
SSL_ERROR_WANT_READ on an accepted connection. Polling and 
subsequent accept calls may also fail to report the error, causing
applications to continue waiting after a permanent failure.

* #33278
A retryable write failure on a nonblocking connection accepted 
from a DTLS listener can be reported as SSL_ERROR_SYSCALL instead
of SSL_ERROR_WANT_WRITE. Applications treating this result as
fatal may close a connection that is still usable.

* #33242
DTLS 1.3 servers may abort handshakes with an unexpected_message
alert when a client acknowledges part or all of the server's
first flight before sending its response. This can occur after
packet loss or while the client is preparing its authentication
response.

Fixes for these issues are in progress and planned for the next 4.1 patch
release.

Yours,

The OpenSSL Project Team.