OpenSSL 4.0.0 - News

← Back to newsDiscussions: hackernewsArticle43 Comments

OpenSSL 4.0.0 is a feature release adding significant new functionality
to OpenSSL.

This release incorporates the following potentially significant or incompatible
changes:

  • Removed extra leading '00:' when printing key data such as an RSA modulus
    in hexadecimal format where the first (most significant) byte is >= 0x80.

  • Standardized the width of hexadecimal dumps to 24 bytes for signatures
    (to stay within the 80 characters limit) and 16 bytes for everything else.

  • Lower bounds checks are now enforced when using PKCS5_PBKDF2_HMAC API
    with FIPS provider.

  • Added AKID verification checks when X509_V_FLAG_X509_STRICT is set.

  • Augmented CRL verification process with several additional checks.

  • libcrypto no longer cleans up globally allocated data via atexit().

  • BIO_snprintf() now uses snprintf() provided by libc instead of internal
    implementation.

  • OPENSSL_cleanup() now runs in a global destructor, or not at all
    by default.

  • ASN1_STRING has been made opaque.

  • Signatures of numerous API functions, including those that are related
    to X509 processing, are changed to include const qualifiers for argument
    and return types, where suitable.

  • Deprecated X509_cmp_time(), X509_cmp_current_time(),
    and X509_cmp_timeframe() in favor of X509_check_certificate_times().

  • Removed support for the SSLv2 Client Hello.

  • Removed support for SSLv3. SSLv3 has been deprecated since 2015,
    and OpenSSL had it disabled by default since version 1.1.0 (2016).

  • Removed support for engines. The no-engine build option
    and the OPENSSL_NO_ENGINE macro are always present.

  • Support of deprecated elliptic curves in TLS according to RFC 8422 was
    disabled at compile-time by default. To enable it, use the
    enable-tls-deprecated-ec configuration option.

  • Support of explicit EC curves was disabled at compile-time by default.
    To enable it, use the enable-ec_explicit_curves configuration option.

  • Removed c_rehash script tool. Use openssl rehash instead.

  • Removed the deprecated msie-hack option from the openssl ca command.

  • Removed BIO_f_reliable() implementation without replacement.
    It was broken since 3.0 release without any complaints.

  • Removed deprecated support for custom EVP_CIPHER, EVP_MD, EVP_PKEY,
    and EVP_PKEY_ASN1 methods.

  • Removed deprecated fixed SSL/TLS version method functions.

  • Removed deprecated functions ERR_get_state(), ERR_remove_state()
    and ERR_remove_thread_state(). The ERR_STATE object is now always
    opaque.

  • Dropped darwin-i386{,-cc} and darwin-ppc{,64}{,-cc} targets
    from Configurations.

This release adds the following new features:

  • Support for Encrypted Client Hello (ECH, RFC 9849).
    See doc/designs/ech-api.md for details.

  • Support for RFC 8998, signature algorithm sm2sig_sm3, key exchange
    group curveSM2, and [tls-hybrid-sm2-mlkem] post-quantum group
    curveSM2MLKEM768.

  • cSHAKE function support as per SP 800-185.

  • "ML-DSA-MU" digest algorithm support.

  • Support for SNMP KDF and SRTP KDF.

  • FIPS self tests can now be deferred and run as needed when installing
    the FIPS module with the -defer_tests option of the openssl fipsinstall
    command.

  • Support for using either static or dynamic VC runtime linkage
    on Windows.

  • Support for negotiated FFDHE key exchange in TLS 1.2 in accordance
    with RFC 7919.