OpenSSL 4.1.0 (installer revision 2)

Installer revision 2. This is an installer-only fix. OpenSSL is unchanged: the same openssl-4.1.0 and FIPS openssl-3.1.2 sources as 4.1.0-1.

• The libcrypto and libssl DLLs in the x86 and arm64 installers are now Authenticode-signed; in 4.1.0-1 they were not (#30).
• 4.1.0-2 has the same version number as 4.1.0-1, so it does not upgrade it. If 4.1.0-1 is installed, uninstall it first (Settings > Apps > OpenSSL Library), then install 4.1.0-2.

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

• openssl/openssl#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. A fix is in progress and planned for a future
  release.

• openssl/openssl#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.

• openssl/openssl#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.

• openssl/openssl#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.

Windows installers

Built from openssl-4.1.0 with the FIPS 140-3 validated provider from openssl-3.1.2, using installer commit da213f8. All installers and the files they install are signed by OpenSSL Software Services Czech, s.r.o. See the README for the available variants and the command-line options.