If php_random_bytes_throw fails, the nonce will be uninitialized, but
still sent to the server. The client nonce is intended to protect
against a malicious server. See section 5.10 and 5.12 of RFC 7616 [1],
and bullet point 2 below.
Tim pointed out that even though it's the MD5 of the nonce that gets sent,
enumerating 31 bits is trivial. So we have still a stack information leak
of 31 bits.
Furthermore, Tim found the following issues:
* The small size of cnonce might cause the server to erroneously reject
a request due to a repeated (cnonce, nc) pair. As per the birthday
problem 31 bits of randomness will return a duplication with 50%
chance after less than 55000 requests and nc always starts counting at 1.
* The cnonce is intended to protect the client and password against a
malicious server that returns a constant server nonce where the server
precomputed a rainbow table between passwords and correct client response.
As storage is fairly cheap, a server could precompute the client responses
for (a subset of) client nonces and still have a chance of reversing the
client response with the same probability as the cnonce duplication.
Precomputing the rainbow table for all 2^31 cnonces increases the rainbow
table size by factor 2 billion, which is infeasible. But precomputing it
for 2^14 cnonces only increases the table size by factor 16k and the server
would still have a 10% chance of successfully reversing a password with a
single client request.
This patch fixes the issues by increasing the nonce size, and checking
the return value of php_random_bytes_throw(). In the process we also get
rid of the MD5 hashing of the nonce.
[1] RFC 7616: https://www.rfc-editor.org/rfc/rfc7616
Co-authored-by: Tim Düsterhus <timwolla@php.net>
Fix it by extending the array sizes by one character. As the input is
limited to the maximum path length, there will always be place to append
the slash. As the php_check_specific_open_basedir() simply uses the
strings to compare against each other, no new failures related to too
long paths are introduced.
We'll let the DOM and XML case handle a potentially too long path in the
library code.
PHP’s implementation of crypt_blowfish differs from the upstream Openwall
version by adding a “PHP Hack”, which allows one to cut short the BCrypt salt
by including a `$` character within the characters that represent the salt.
Hashes that are affected by the “PHP Hack” may erroneously validate any
password as valid when used with `password_verify` and when comparing the
return value of `crypt()` against the input.
The PHP Hack exists since the first version of PHP’s own crypt_blowfish
implementation that was added in 1e820eca02.
No clear reason is given for the PHP Hack’s existence. This commit removes it,
because BCrypt hashes containing a `$` character in their salt are not valid
BCrypt hashes.
When traversing the result array, we need to cater to `param_name`
possibly being `NULL`. Prior to PHP 7.0.0, this was implicitly done
because `param_name` was of type `char*`.
Closes GH-9739.
The issue is that PS(mod)->s_validate_sid is always defined for user modules, thus we need to check that the actual callable is set
Add another regression test to ensure current working behaviour is not broken (which was by the previous incorrect fix)
Closes GH-9638
Commit fbe3059 included an unintended change to the test which checks if
dns_get_record populates its additional parameter. This patch reverts
such change.
The issue was not detected by the CIs because their tests run in
the --offline mode, and the test in question needs internet connection.
Closes GH-9625.
When a tar phar is created, `phar_open_from_fp()` is also called, but
since the file has just been created, none of the format checks can
succeed, so we continue to loop, but must not check again for the
format. Therefore, we bring back the old `test` variable.
Closes GH-9620.
The phar wrapper needs to uncompress the file; the uncompressed file
might be compressed, so the wrapper implementation loops. This raises
potential DOS issues regarding too deep or even infinite recursion (the
latter are called compressed file quines[1]). We avoid that by
introducing a recursion limit; we choose the somewhat arbitrary limit
`3`.
This issue has been reported by real_as3617 and gPayl0ad.
[1] <https://honno.dev/gzip-quine/>
