PHP hash_algos() Function: Usage and Examples

hash_algos lists hash algorithm identifiers supported by the current PHP hash extension, including algorithms unsuitable for security.

The examples explain the data format, expected results and the difference between this API and nearby cryptographic operations.

What It Does

The operation is intended for: hash_algos lists hash algorithm identifiers supported by the current PHP hash extension, including algorithms unsuitable for security.

Part of core PHP or a normally bundled standard extension; check your deployment configuration.

Syntax and Return Value

hash_algos(): array

This API accepts no required parameters, or its signature must be checked on the target runtime.

The declared return type is shown above. Errors can include false results or exceptions depending on this API: An ordinary hash is not encryption and is not a password-storage function. Use HMAC when a shared-secret authenticity check is needed.

Example 1: Basic Operation

Inspect the expected result: do not print secrets or reuse illustrative credentials in production.

<?php
$available = hash_algos();
var_dump(in_array("sha256", $available, true));

Example 2: A Different Use Case

Inspect available algorithms rather than assuming a requested identifier exists.

<?php
// Check the alternative case.
$available = hash_algos();
var_dump(in_array("sha512", $available, true));

Practical Example: Checking the Result

Inspect available algorithms rather than assuming a requested identifier exists.

<?php
// Verify the expected behavior before using results.
$available = hash_algos();
echo count($available);

Important Behavior and Edge Cases

An ordinary hash is not encryption and is not a password-storage function. Use HMAC when a shared-secret authenticity check is needed.

Distinguish digest encoding from secret-key authentication and keep fixed-length expected authentication values for comparisons.

Comparison with Related Functions

Common Beginner Mistakes

Key Takeaways

• hash_algos lists hash algorithm identifiers supported by the current PHP hash extension, including algorithms unsuitable for security.
• An ordinary hash is not encryption and is not a password-storage function. Use HMAC when a shared-secret authenticity check is needed.
• hash() computes a digest in one call; hash_init/hash_update/hash_final support incremental input.

Apply this behavior to a real application only after confirming the required extension, configuration and failure handling on the deployment runtime.