Problem decrypting data stored in MySQL using mcrypt

Hi All,

I'm trying to implement encryption on certain data fields in my MySQL
database and I'm experiencing ongoing problems.

I seem to be able to encrypt the data without issues, but can't figure
out how to decrypt the data.

My field in my test table, in which I'm storing the encrypted data, is
a TEXT type field.

The code I'm using, from the PHP help file, is:

[ begin code ]

$key = "mysecretkey";
$input = "This is some plain text.";
$td = mcrypt_module_open ('tripledes', '', 'ecb', '');
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND);
mcrypt_generic_init ($td, $key, $iv);
$encrypted_data = mcrypt_generic ($td, $input);
$insq = "INSERT into test (entry) VALUES ('$encrypted_data')";
mysql_query($insq);
mcrypt_generic_deinit ($td);
mcrypt_module_close ($td);
$query = "SELECT entry from test";
$res = mysql_query($query);
$row = mysql_fetch_array($res);
mysql_free_result($res);
$et = $row["entry"];
$td = mcrypt_module_open ('tripledes', '', 'ecb', '');
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND);
mcrypt_generic_init ($td, $key, $iv);
$plain = mdecrypt_generic ($td, $et);
mcrypt_generic_deinit ($td);
mcrypt_module_close ($td);
echo "$input<p>$et<p>$plain<p>";

[ end code ]

The output from the echo statement, which I was expecting to be
<plaintext> <encrypted text> <decrypted plaintext>, is:

[ begin echo output]

This is some plain text.

#faÖŸdšK𳵚"‡Á¸•Š‹ßÐt£

#faÖŸdšK𳵚"‡Á¸•Š‹ßÐt£

[ end echo output ]

I assume some of the characters won't display properly in this post,
however I can verify that the <encrypted text> (line 2) and <decrypted
plaintext> (line 3) appear to be identical.

Can anyone give me an insight into what I'm doing wrong?

I'm using PHP version 4.3.4 and Apache 1.3.28 on WindowsXP, if these
are meaningful.

Any help will be immensely appreciated!

Much warmth,

Murray
http://www.planetthoughtful.org
Building a thoughtful planet,
One quirky comment at a time.

"M Wells" <planetquirky@planetthoughtful.org> wrote in message
news:bit210liidvt9vvcio7lrt1o937prf4vdb@4ax.com...
> Hi All,
>
> I'm trying to implement encryption on certain data fields in my MySQL
> database and I'm experiencing ongoing problems.
>
> I seem to be able to encrypt the data without issues, but can't figure
> out how to decrypt the data.
>
> My field in my test table, in which I'm storing the encrypted data, is
> a TEXT type field.
>
> The code I'm using, from the PHP help file, is:
>
> [ begin code ]
>
> $key = "mysecretkey";
> $input = "This is some plain text.";
> $td = mcrypt_module_open ('tripledes', '', 'ecb', '');
> $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND);
> mcrypt_generic_init ($td, $key, $iv);
> $encrypted_data = mcrypt_generic ($td, $input);
> $insq = "INSERT into test (entry) VALUES ('$encrypted_data')";
> mysql_query($insq);
> mcrypt_generic_deinit ($td);
> mcrypt_module_close ($td);
> $query = "SELECT entry from test";
> $res = mysql_query($query);
> $row = mysql_fetch_array($res);
> mysql_free_result($res);
> $et = $row["entry"];
> $td = mcrypt_module_open ('tripledes', '', 'ecb', '');
> $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size ($td), MCRYPT_RAND);
> mcrypt_generic_init ($td, $key, $iv);
> $plain = mdecrypt_generic ($td, $et);
> mcrypt_generic_deinit ($td);
> mcrypt_module_close ($td);
> echo "$input<p>$et<p>$plain<p>";
>
> [ end code ]
>
> The output from the echo statement, which I was expecting to be
> <plaintext> <encrypted text> <decrypted plaintext>, is:
>
> [ begin echo output]
>
> This is some plain text.
>
> #faÖYdsKð³µs"?Á¸.S<ßÐt£
>
> #faÖYdsKð³µs"?Á¸.S<ßÐt£
>
> [ end echo output ]
>
> I assume some of the characters won't display properly in this post,
> however I can verify that the <encrypted text> (line 2) and <decrypted
> plaintext> (line 3) appear to be identical.
>
> Can anyone give me an insight into what I'm doing wrong?
>
> I'm using PHP version 4.3.4 and Apache 1.3.28 on WindowsXP, if these
> are meaningful.
>
> Any help will be immensely appreciated!
>
> Much warmth,
>
> Murray
> http://www.planetthoughtful.org
> Building a thoughtful planet,
> One quirky comment at a time.

I can't see where you're going wrong - but if I were you, I'd concentrate on
getting the encryption/decryption working first, before doing anything with
the result to/from MySQL - I am a newbie at MySQL and I'm wondering if the
data being stored is different than that being recovered)... You could try
and do an md5 hash on the encrypted data send to and from the database and
compare them both - If the hashes are different, then the data you are
reading back might look the same ,but are different...

Thats about as much as I can suggest...