HASH_INIT(3) 1 HASH_INIT(3)
hash_init - Initialize an incremental hashing context
SYNOPSIS
resource hash_init NULL (string $algo, [int $options], [string $key])
DESCRIPTION
PARAMETERS
o $algo
- Name of selected hashing algorithm (i.e. "md5", "sha256", "haval160,4", etc..). For a list of supported algorithms see
hash_algos(3).
o $options
- Optional settings for hash generation, currently supports only one option: HASH_HMAC. When specified, the $key must be speci-
fied.
o $key
- When HASH_HMAC is specified for $options, a shared secret key to be used with the HMAC hashing method must be supplied in this
parameter.
RETURN VALUES
Returns a Hashing Context resource for use with hash_update(3), hash_update_stream(3), hash_update_file(3), and hash_final(3).
EXAMPLES
Example #1
Incremental hashing example
<?php
$ctx = hash_init('md5');
hash_update($ctx, 'The quick brown fox ');
hash_update($ctx, 'jumped over the lazy dog.');
echo hash_final($ctx);
?>
The above example will output:
5c6ffbdd40d9556b73a21e63c3e0e904
SEE ALSO
hash(3), hash_algos(3), hash_file(3), hash_hmac(3), hash_hmac_file(3).
PHP Documentation Group HASH_INIT(3)
