#30891 [Opn]: mcrypt_generic_init() not returning negative integer on error

ID:               30891
User updated by:  brian_bisaillon at rogers dot com
Reported By:      brian_bisaillon at rogers dot com
Status:           Open
Bug Type:         Documentation problem
Operating System: SuSE Linux 9.1
PHP Version:      5.0.2
New Comment:

Derick,

I'm glad it's not a bug. I will update my code to take into account
that a FALSE integer means that the encryption
identifier is invalid.

Thanks guys!


Previous Comments:
------------------------------------------------------------------------

[2004-11-25 22:57:59] derick@php.net

There is no bug here, it simply returns false when an invalid
encryption parameter is passed:

derick@kossu:~$ php -r 'var_dump(mcrypt_generic_init("foo", "key",
"1"));'

Warning: mcrypt_generic_init(): supplied argument is not a valid MCrypt
resource in Command line code on line 1
bool(false)

The documentation is slightly wrong:

The function returns a negative value on error, -3 when the key length
was incorrect, -4 when there was a memory allocation problem and any
other return value is an unknown error.

It should state that returning bool(false) means that the encryption
identifier is invalid.

------------------------------------------------------------------------

[2004-11-25 22:47:50] tony2001@php.net

Thank you for this bug report. To properly diagnose the problem, we
need a short but complete example script to be able to reproduce
this bug ourselves.

A proper reproducing script starts with <?php and ends with ?>,
is max. 10-20 lines long and does not require any external
resources such as databases, etc.

If possible, make the script source available online and provide
an URL to it here. Try avoid embedding huge scripts into the report.



------------------------------------------------------------------------

[2004-11-25 05:08:10] brian_bisaillon at rogers dot com

My error checking for -3 worked so it's setting a negative integer when
I supply an invalid $encryptionKey. However, the problem is with
returning negative integers for "unknown errors" such as an invalid
MCrypt resource. In those situations, it doesn't return a negative
integer like it's supposed to.

------------------------------------------------------------------------

[2004-11-25 05:00:28] brian_bisaillon at rogers dot com

Description:
------------
./configure --prefix=/opt/php
--with-apxs2=/opt/apache/bin/apxs \
--with-mod_charset --disable-cgi --enable-magic-quotes
--with-openssl \
--with-libxml-dir=/usr/lib --with-zlib --enable-bcmath
--with-bz2 \
--enable-calendar --with-jpeg-dir=/usr/lib
--with-tiff-dir=/usr/lib \
--with-curl --with-curlwrappers --with-db4 --with-cdb
--with-inifile \
--with-flatfile --enable-dbase --enable-dbx --enable-dio
--with-fam \
--enable-filepro --enable-ftp --with-gd
--with-png-dir=/usr/lib \
--with-xpm-dir=/usr/lib --with-ttf
--with-freetype-dir=/usr/lib \
--with-gettext --with-gmp --with-kerberos --with-ldap
--with-ldap-sasl \
--enable-mbstring --with-mcrypt --with-mhash
--with-mysql=/opt/mysql \
--with-mysqli=/opt/mysql/bin/mysql_config --with-ncurses
--with-unixODBC \
--with-pgsql=/opt/postgresql --with-readline
--enable-shmop --with-snmp \
--enable-ucd-snmp-hack --enable-soap --enable-sockets \
--enable-sqlite-utf8 --enable-sysvmsg --enable-sysvsem
--enable-sysvshm \
--with-tidy=/usr --enable-wddx --with-xmlrpc --with-xsl
--enable-yp \
--enable-maintainer-zts --enable-memory-limit
--enable-zend-multibyte \
--with-tsrm-pthreads

Reproduce code:
---------------
$returnValue =
@mcrypt_generic_init($this->encryptionDescriptor, $encryptionKey,
$this->SetRandomIv());
if (0 == intval($returnValue) && -3 !== $returnValue && -4
!== $returnValue) {
throw new Exception("<h1>\n  Initialization
Failed\n</h1>\n<strong>Fatal:</strong> mcrypt_generic_init(): An
unknown error occurred : phpwebtk.cryptography.Crypt.Exception
<strong>");
} else if (-3 == $returnValue) {
throw new Exception("<h1>\n  Initialization
Failed\n</h1>\n<strong>Fatal:</strong> mcrypt_generic_init(): The key
length was incorrect : phpwebtk.cryptography.Crypt.Exception
<strong>");
} else if (-4 == $returnValue) {
throw new Exception("<h1>\n  Initialization
Failed\n</h1>\n<strong>Fatal:</strong> mcrypt_generic_init(): There was
a memory allocation problem : phpwebtk.cryptography.Crypt.Exception
<strong>");
} else {
$ciphertext =
mcrypt_generic($this->encryptionDescriptor, $plaintext);
mcrypt_generic_deinit($this->encryptionDescriptor);
$this->CloseModule();
}

Expected result:
----------------
I expected the $returnValue to be a negative integer since
I gave a bogus $this->encryptionDescriptor and according
to the PHP manual, mcrypt_generic_init is supposed to
return a negative integer on error.

Actual result:
--------------
$returnValue was null despite the fact that
$this->encryptionDescriptor was invalid. It showed the
warning but I want to throw my own custom exception and
use the @mcrypt_generic_init() syntax to hide the default
warning. I cannot do that if a negative integer is not
being returned upon an error.


------------------------------------------------------------------------


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Edit this bug report at http://bugs.php.net/?id=30891&edit=1