4.0.0

xmlseclibs 4.0.0

PHP 8.0+ and phpseclib/phpseclib ~3.0 required; OpenSSL is optional.

Highlights

• Crypto moved to phpseclib (symmetric, RSA, RSA-OAEP, X.509); RSA-PSS (RSA_SHA256_MGF1) supported
• Safe-by-default verifyDocument() — pinned key, algorithm allowlists, validated node set
• enableLegacyMode() for temporary pre-4.0 interop while migrating peers
• Compact templates via stripWhitespace; omit_uri for references without a URI; extensibility via protected members (#152)

Security (breaking defaults)

• DOCTYPE rejected on signature verify (entity-ref / Id bypass; same class of issue as CVE-2025-23369); also rejected in decrypted XML
• XPath Filtering Transforms rejected on verify by default (pre-auth DoS); capped when enabled
• RSA-1.5 key transport denied on decrypt by default; uniform decrypt errors (no padding oracle)
• verify() always binds SignatureMethod to the supplied key; HMAC cannot be loaded from certs/PEM
• References fail closed (unknown transforms, external/duplicate-Id URIs, unknown C14N)
• SSRF hardening on add509Cert() URL fetch; EncryptedKey/RetrievalMethod depth caps; hash_equals for digests/HMAC

Other

• Configurable transforms element; setSignatureId(); clearer throws when signature context is missing
• Interop: whitespace-stripped signature/EncryptedData templates for C# SignedXml / Python signxml-style peers
• PHP 8 / static-analysis hardening; PHP 8.5 deprecation fix in makeAsnSegment()

Migration

Prefer verifyDocument() with a pinned key. Use enableLegacyMode() only while updating peers — it restores DOCTYPE-on-verify, XPath transforms, and RSA-1.5; it does not undo algorithm/key binding, uniform decrypt errors, or decrypted-XML DOCTYPE rejection. Prefer RSA-OAEP and AES-GCM for new deployments.

Full detail: CHANGELOG.txt (4.0.0) and the “Breaking changes (3.1 → 4.0)” section in README.md.

Full Changelog: 3.1.5...4.0.0