cloudflare/boring v5.0.0-alpha.1

v5.0.0-alpha.1

Repository: cloudflare/boring

Tag: v5.0.0-alpha.1

Published: 2026-01-21T17:25:12Z

Prerelease: yes

Release notes:

Breaking changes

Upgrade to 4.21.1 first and fix any deprecation warnings.

Cargo features removed/simplified

• FIPS only needs the fips Cargo feature, and the rest is customized via env vars (like BORING_BSSL_FIPS_PATH): https://github.com/cloudflare/boring/pull/383
• Removed the "kx-*" features https://github.com/cloudflare/boring/pull/393
• Post-quantum is enabled by default (X25519MLKEM768 and P256Kyber768Draft00) and the "pq-experimental" Cargo feature flag is not used any more.

Other changes

• Updated BoringSSL to a newer version with updated patches by @nox in https://github.com/cloudflare/boring/pull/419
• Removed SslCurve API. Identifying curves by name is more reliable across different builds of BoringSSL. https://github.com/cloudflare/boring/pull/390
• Removed deprecated X509CheckFlags https://github.com/cloudflare/boring/pull/425
• X509Store is immutable, but cloneable https://github.com/cloudflare/boring/pull/426
• Minimum Hyper version upgraded from v0
• Added SslRef::curve_name() by @ghedo in https://github.com/cloudflare/boring/pull/396
• Added set_ticket_key_callback (SSL_CTX_set_tlsext_ticket_key_cb) by @toidiu in https://github.com/cloudflare/boring/pull/330
• SslCipherRef::protocol_id by @nox in https://github.com/cloudflare/boring/pull/409
• set_strict_cipher_list by @abernardeau-wallix in https://github.com/cloudflare/boring/pull/416
• set_ex_data() will always Drop previous values https://github.com/cloudflare/boring/pull/424
• Removed blanket Eq from FFI types
• BIO_set_retry_write on WouldBlock @ihciah in https://github.com/cloudflare/boring/pull/118

Full Changelog: https://github.com/cloudflare/boring/compare/v4.19.0...v5.0.0-alpha.1