php-in-php: hash_pbkdf2() — native VmHash path without host \\hash_pbkdf2() (ext/hash/hash_pbkdf2.c, bootstrap) #6186

Category

php-in-php / bootstrap

Problem

hash_pbkdf2() VM implementation delegates to host Zend \hash_pbkdf2() (ext/standard/VmHash.php line 35). That blocks self-host/AOT paths where host ext/hash is absent and violates PHP-in-PHP: PBKDF2 semantics belong in ext/ + existing VmHashNative FFI, not permanent host delegation.

Enum-case operand TypeError parity is tracked separately (#5972); this issue is the native implementation + host delegation removal.

php-src reference

• ext/hash/hash_pbkdf2.c — PHP_FUNCTION(hash_pbkdf2) HMAC-based PBKDF2
• ext/hash/php_hash.h — algorithm dispatch

Repro (bootstrap)

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
grep -n "hash_pbkdf2" ext/standard/VmHash.php
php bin/vm.php -r "echo hash_pbkdf2(\"sha256\", \"pass\", \"salt\", 1, 8);\n";"
'

Today VmHash::hashPbkdf2() contains return \hash_pbkdf2(...).

Scope (this repo)

• Implement PBKDF2 in ext/standard/VmHashNative.php (or sibling) using existing OpenSSL/libsodium FFI patterns from VmHashNative
• Wire ext/standard/hash_pbkdf2.php VM path to native helper
• JIT/AOT: lower through VmHashNative / delete any C-only shortcut tables
• Delete host \hash_pbkdf2() call from VmHash.php
• Lines removed from C: none expected (no new runtime/*.c); shrink host dependency surface

Done when

• hash_pbkdf2('sha256', 'pass', 'salt', 1, 8) returns deterministic digest matching Zend on VM
• No \hash_pbkdf2( host calls remain under ext/standard/VmHash.php
• test/compliance/cases/stdlib/hash_pbkdf2_basic.phpt green on VM
• JIT/AOT smoke when lowering lands (script/capability-matrix.php notes updated)
• make bootstrap-inventory-check still green (ext/hash on spine path)

Related: #5972 (enum operands), #4790 / #5989 (VmHashNative / hash_crypto.c deletion), #3773 (original parity).