Stdlib: hash_init()/hash_update()/hash_final()/hash_copy() — VmHashContext incremental handlers (phase 1 of #3357) #7174

Category

stdlib | php-in-php

Problem

#6937 (closed) registered ext/hash skeleton stubs so function_exists('hash_init') is true, but hash_init() still throws Error: … not implemented in this compiler build (issue #3357). Streaming/incremental hashing and hash_copy() fork semantics are blocked for frameworks, file digest loops, and self-host paths that expect ext/hash parity.

Verified 2026-06-06:

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php bin/vm.php -r "var_export(function_exists(\"hash_init\")); echo PHP_EOL; hash_init(\"sha256\");" 2>&1 | head -4
'
# true
# Fatal: hash_init() is not implemented in this compiler build (issue #3357)

php-src reference

• php/php-src ext/hash/hash.c — php_hash_init, php_hash_update, php_hash_final, php_hash_copy
• php/php-src ext/hash/hash.stub.php — HashContext object model (PHP 8+)
• php/php-src ext/hash/php_hash.h — context lifecycle (hash_final invalidates; hash_copy independent clone)

Repro

<?php
$ctx = hash_init('sha256');
hash_update($ctx, 'hello ');
hash_update($ctx, 'world');
echo hash_final($ctx), "\n";

$ctx2 = hash_copy($ctx);
echo hash_final($ctx2), "\n";

./script/docker-exec.sh -- bash -lc 'source script/php-env.sh
php repro_hash_context.php
php bin/vm.php repro_hash_context.php 2>&1 | head -5
'

Scope (PHP-in-PHP first)

php-src-strict

• Invalid algo → ValueError (match one-shot hash()).
• Enum-case operands on string params → TypeError naming enum class (Stdlib: hash()/hash_hmac()/md5()/sha1()/crc32() — enum case operands must TypeError (ext/hash, ext/standard) #5780 pattern), not backing scalar coercion.
• hash_final($ctx) invalidates $ctx; second final → catchable Error per Zend.

Done when

• Repro prints two identical SHA-256 hex digests on VM
• hash_copy() produces independent context; updating one does not affect the other
• test/compliance/cases/stdlib/hash_context_incremental.phpt green under php bin/vm.php
• ./script/ci-fast.sh --filter hash_context_incremental passes
• Capability matrix updated; umbrella Stdlib: hash_init() / hash_update() / hash_final() / hash_copy() — incremental ext/hash API #3357 can close when PBKDF2/HKDF siblings also green