Following an offline discussion with some internals folks, I've put together
a general hashing extensions which could potentially find a place in core as
an enabled by default extension:
ext/hash:
string hash(string $algo, string $value[,$raw=false])
string hash_file(string $algo, string $filename[,$raw=false])
Where $algo is (currently) any of 'md5', 'sha1', 'sha256', 'sha384',
'sha512', 'ripemd128', 'ripemd160' each of which are implemented internally
using raw math and no library dependencies. I've also got an upgrade path
laid out for extracting md5() and sha1() from core in future versions (6.0?)
without compromising backward compatability.
The extension also supports incremental hashing:
resource hash_init($algo);
bool hash_update($context, $data);
string hash_final($context[,$raw=false])
External extensions can already "register" additional hashing algos using
the module dependency hooks now available.
For the future I've got plans for allowing registration of userspace hashing
functions, HMAC support, and a streams filter implementation as well as
additional engines: crc, haval, md4, etc...
Examples:
$digest = hash('sha256', 'abc');
$ctx = hash_init('sha256');
hash_update($ctx, 'a');
hash_update($ctx, 'bc');
$digest = hash_final($ctx);
I'm just putting on some finishing touches and will post a tarball later
today.
-Sara
I'm just putting on some finishing touches and will post a tarball later
today.
Meh... It'll be easier to discuss within CVS... It's in pecl/hash as of now.
-Sara
Sara Golemon wrote:
string hash(string $algo, string $value[,$raw=false])
string hash_file(string $algo, string $filename[,$raw=false])
Hm... hash(string $value[, $algo='sha256' [,$raw=false]])?
Assuming that sha256 is always going to be the best default is pretty
short-sighted.
It's only a matter of time before that one is partially broken in some
way too; we won't be able to change the default value of the function
by then, because everyone using the default will have code that
depends on sha256, and voila, we've gotten locked into something that
might not be so desirable.
Default values should be avoided unless they're always going to make sense.
--Wez.
Sara Golemon wrote:
string hash(string $algo, string $value[,$raw=false])
string hash_file(string $algo, string $filename[,$raw=false])Hm... hash(string $value[, $algo='sha256' [,$raw=false]])?
Hi,
I'm missing the functionality to get a list of registered hash functions
so one can probe whether a certain hash function is available or not.
- Markus
I'm missing the functionality to get a list of registered hash functions
so one can probe whether a certain hash function is available or not.
There is now :)
array hash_algos(void)
Returns numerically indexed array of hashing engine names.
And just incase anyone missed it. The proto for hash_init() has been
extended:
resource hash_init(string algo[, int options, string key])
Options currently has one possible value: HASH_HMAC
When specified, key must be specified as well (to be used for the HMAC key).
HMAC can be used with any of the hashing algos included in ext/hash.
Examples of using HMAC with official test vectors can be found in
tests/hmac-md5.phpt
I'd rather not complicate the proto for the core hash() function with HMAC
and other options, but maybe a separate hash_hmac() and/or hash_hmac_file()
might be in order?
-Sara