Most of these have been skipped on Windows for no good reason (`lstat`
is available there as of PHP 4). Several others would only fail,
because the `blksize` and `blocks` elements are always `-1` on Windows,
which can easily be fixed by using `%i` format specifiers instead of
`%d`.
* Modify php_hash_ops to contain the algorithm name and
serialize and unserialize methods.
* Implement __serialize and __unserialize magic methods on
HashContext.
Note that serialized HashContexts are not necessarily portable
between PHP versions or from architecture to architecture.
(Most are, though Keccak and slow SHA3s are not.)
An exception is thrown when an unsupported serialization is
attempted.
Because of security concerns, HASH_HMAC contexts are not
currently serializable; attempting to serialize one throws
an exception.
Serialization exposes the state of HashContext memory, so ensure
that memory is zeroed before use by allocating it with a new
php_hash_alloc_context function. Performance impact is
negligible.
Some hash internal states have logical pointers into a buffer,
or sponge, that absorbs input provided in bytes rather than
chunks. The unserialize functions for these hash functions
must validate that the logical pointers are all within bounds,
lest future hash operations cause out-of-bounds memory accesses.
* Adler32, CRC32, FNV, joaat: simple state, no buffer positions
* Gost, MD2, SHA3, Snefru, Tiger, Whirlpool: buffer positions
must be validated
* MD4, MD5, SHA1, SHA2, haval, ripemd: buffer positions encoded
bitwise, forced to within bounds on use; no need to validate
Previously, the Keccak_HashInstance was separately allocated.
This could cause memory leaks on errors. For instance,
in php_hash_do_hash_hmac, the following code cleans up after
a file read error:
if (n < 0) {
efree(context);
efree(K);
zend_string_release(digest);
RETURN_FALSE;
}
This does not call the context's hash_final operation, which
was the only way to free the separately-allocated Keccak state.
The simplest fix is simply to place the Keccak_HashInstance state
inside the context object. Then it doesn't need to be freed.
As a result, there is no need to call hash_final in the
HashContext destructor: HashContexts cannot contain internally
allocated resources.
A `BSTR` is similar to a `zend_string`; it stores the length of the
string just before the actual string, and thus the string may contain
NUL bytes. However, `php_com_olestring_to_string()` is supposed to
deal with arbitrary `OLECHAR*`s which may not be `BSTR`s, so we
introduce `php_com_bstr_to_string()` and use it for the only case where
we actually have to deal with `BSTR`s which may contain NUL bytes.
Contrary to `php_com_olestring_to_string()` we return a `zend_string`,
so we can save the re-allocation when converting to a `zval`.
We also cater to `php_com_string_to_olestring()` not being binary safe,
with basically the same fix we did for `php_com_olestring_to_string()`.
Casting objects to bool is supposed to yield `true`. Since the
`cast_object` handler is required now, we have to implement the
`_IS_BOOL` conversion there.
This properly addresses the issue from bug #79741. Silently
interpreting objects as mangled property tables is almost
always a bad idea.
Closes GH-5773.
exit() is now internally implemented by throwing an exception,
performing a normal stack unwind and a clean shutdown. This ensures
that no persistent resource leaks occur.
The exception is internal, cannot be caught and does not result in
the execution of finally blocks. This may be relaxed in the future.
Closes GH-5768.
Dmitry Stogov