web-based and command line mcrypting and back again

I am trying to figure out how to encrypt data using the web-based php
mcrypt function and then decrypt it using the command line (cli) mcrypt
binary, and vica-versa.

I cannot seem to get the same encrypted output for the same data,
between the two methods. I've tried to ensure I am using the same
algorithms and modes for both methods by testing the mcrypt_enc_get_*
functions. I think the problem may lie in the way both methods are
being seeded.

Web-Based PHP Example:

$key = 'test';
$data[] = 'abcdefghijklmnopqrstuvwxyz';
$m = 0;

foreach ($data as $dt)
{
$td = mcrypt_module_open('tripledes', '', 'ecb', '');
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
mcrypt_generic_init($td, $key, $iv);
$CRYPT[$m] = mcrypt_generic($td, $dt);

/*
echo mcrypt_enc_get_algorithms_name($td);
echo mcrypt_enc_get_block_size($td);
echo mcrypt_enc_get_iv_size($td);
echo mcrypt_enc_get_key_size($td);
echo mcrypt_enc_get_modes_name($td);
echo mcrypt_enc_get_supported_key_sizes($td);
echo mcrypt_enc_is_block_algorithm_mode($td);
echo mcrypt_enc_is_block_algorithm($td);
echo mcrypt_enc_is_block_mode($td);
echo mcrypt_enc_self_test($td);
*/

$DECRYPT[$m] = mdecrypt_generic($td, $dt);
mcrypt_generic_deinit($td);
mcrypt_module_close($td);

echo "crypt_" . base64_encode($CRYPT[$m]) . "_<br />\n";
echo "decrypt_" . base64_decode(rtrim($DECRYPT[$m])) . "_<br />\n";

$m++;
}

Note: I believe it is the line where the $iv variable is being set that
is causing the issue and/or I cannot reproduce the same seeding using
the command line options.


Command Line Example:

echo "abcdefghijklmnopqrstuvwxyz" | mcrypt -Fb -m ecb -a tripledes |
encode-base64

echo "" | decode-base64 | mcrypt -dFb -m ecb -a tripledes


I would appreciate any comments or suggestions.

Respectfully,


Gary

Hi,

Tuesday, January 6, 2004, 8:48:17 PM, you wrote:
GCN> I am trying to figure out how to encrypt data using the web-based php
GCN> mcrypt function and then decrypt it using the command line (cli) mcrypt
GCN> binary, and vica-versa.

GCN> I cannot seem to get the same encrypted output for the same data,
GCN> between the two methods. I've tried to ensure I am using the same
GCN> algorithms and modes for both methods by testing the mcrypt_enc_get_*
GCN> functions. I think the problem may lie in the way both methods are
GCN> being seeded.

GCN> Web-Based PHP Example:

GCN> $key = 'test';
GCN> $data[] = 'abcdefghijklmnopqrstuvwxyz';
GCN> $m = 0;

GCN> foreach ($data as $dt)
GCN> {
GCN> $td = mcrypt_module_open('tripledes', '', 'ecb', '');
GCN> $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
GCN> mcrypt_generic_init($td, $key, $iv);
GCN> $CRYPT[$m] = mcrypt_generic($td, $dt);

GCN> /*
GCN> echo mcrypt_enc_get_algorithms_name($td);
GCN> echo mcrypt_enc_get_block_size($td);
GCN> echo mcrypt_enc_get_iv_size($td);
GCN> echo mcrypt_enc_get_key_size($td);
GCN> echo mcrypt_enc_get_modes_name($td);
GCN> echo mcrypt_enc_get_supported_key_sizes($td);
GCN> echo mcrypt_enc_is_block_algorithm_mode($td);
GCN> echo mcrypt_enc_is_block_algorithm($td);
GCN> echo mcrypt_enc_is_block_mode($td);
GCN> echo mcrypt_enc_self_test($td);
GCN> */

GCN> $DECRYPT[$m] = mdecrypt_generic($td, $dt);
GCN> mcrypt_generic_deinit($td);
GCN> mcrypt_module_close($td);

GCN> echo "crypt_" . base64_encode($CRYPT[$m]) . "_<br />\n";
GCN> echo "decrypt_" . base64_decode(rtrim($DECRYPT[$m])) . "_<br />\n";

GCN> $m++;
GCN> }

GCN> Note: I believe it is the line where the $iv variable is being set that
GCN> is causing the issue and/or I cannot reproduce the same seeding using
GCN> the command line options.


GCN> Command Line Example:

GCN> echo "abcdefghijklmnopqrstuvwxyz" | mcrypt -Fb -m ecb -a tripledes |
GCN> encode-base64

GCN> echo "" | decode-base64 | mcrypt -dFb -m ecb -a tripledes


GCN> I would appreciate any comments or suggestions.

GCN> Respectfully,


GCN> Gary


try setting the iv to all 0's
$iv = 0;
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);

--
regards,
Tom

Tom,

I appreciate the suggestion, but even after setting the iv to zero
within the php code and including the --noiv option within the command
line; it still does not produce the same base64 encoded string under
both methods.

I noticed that the command line was keying off of 2 passphrases and the
php code off of only 1, so I forced the command line to key off of only
1 passphrase--to no avail.

I am obviously missing something. Someone out there has had to have
done this at least once before.

Any other suggestions would be appreciated.

Respectfully,


Gary


Tom Rogers wrote:
> Hi,
>
> Tuesday, January 6, 2004, 8:48:17 PM, you wrote:
> GCN> I am trying to figure out how to encrypt data using the web-based php
> GCN> mcrypt function and then decrypt it using the command line (cli) mcrypt
> GCN> binary, and vica-versa.
>
> GCN> I cannot seem to get the same encrypted output for the same data,
> GCN> between the two methods. I've tried to ensure I am using the same
> GCN> algorithms and modes for both methods by testing the mcrypt_enc_get_*
> GCN> functions. I think the problem may lie in the way both methods are
> GCN> being seeded.
>
> GCN> Web-Based PHP Example:
>
> GCN> $key = 'test';
> GCN> $data[] = 'abcdefghijklmnopqrstuvwxyz';
> GCN> $m = 0;
>
> GCN> foreach ($data as $dt)
> GCN> {
> GCN> $td = mcrypt_module_open('tripledes', '', 'ecb', '');
> GCN> $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
> GCN> mcrypt_generic_init($td, $key, $iv);
> GCN> $CRYPT[$m] = mcrypt_generic($td, $dt);
>
> GCN> /*
> GCN> echo mcrypt_enc_get_algorithms_name($td);
> GCN> echo mcrypt_enc_get_block_size($td);
> GCN> echo mcrypt_enc_get_iv_size($td);
> GCN> echo mcrypt_enc_get_key_size($td);
> GCN> echo mcrypt_enc_get_modes_name($td);
> GCN> echo mcrypt_enc_get_supported_key_sizes($td);
> GCN> echo mcrypt_enc_is_block_algorithm_mode($td);
> GCN> echo mcrypt_enc_is_block_algorithm($td);
> GCN> echo mcrypt_enc_is_block_mode($td);
> GCN> echo mcrypt_enc_self_test($td);
> GCN> */
>
> GCN> $DECRYPT[$m] = mdecrypt_generic($td, $dt);
> GCN> mcrypt_generic_deinit($td);
> GCN> mcrypt_module_close($td);
>
> GCN> echo "crypt_" . base64_encode($CRYPT[$m]) . "_<br />\n";
> GCN> echo "decrypt_" . base64_decode(rtrim($DECRYPT[$m])) . "_<br />\n";
>
> GCN> $m++;
> GCN> }
>
> GCN> Note: I believe it is the line where the $iv variable is being set that
> GCN> is causing the issue and/or I cannot reproduce the same seeding using
> GCN> the command line options.
>
>
> GCN> Command Line Example:
>
> GCN> echo "abcdefghijklmnopqrstuvwxyz" | mcrypt -Fb -m ecb -a tripledes |
> GCN> encode-base64
>
> GCN> echo "" | decode-base64 | mcrypt -dFb -m ecb -a tripledes
>
>
> GCN> I would appreciate any comments or suggestions.
>
> GCN> Respectfully,
>
>
> GCN> Gary
>
>
> try setting the iv to all 0's
> $iv = 0;
> $iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
>

Hi,

Wednesday, January 7, 2004, 8:54:16 AM, you wrote:
GCN> Tom,

GCN> I appreciate the suggestion, but even after setting the iv to zero
GCN> within the php code and including the --noiv option within the command
GCN> line; it still does not produce the same base64 encoded string under
GCN> both methods.

GCN> I noticed that the command line was keying off of 2 passphrases and the
GCN> php code off of only 1, so I forced the command line to key off of only
GCN> 1 passphrase--to no avail.

GCN> I am obviously missing something. Someone out there has had to have
GCN> done this at least once before.

GCN> Any other suggestions would be appreciated.

GCN> Respectfully,


GCN> Gary

The only way I could get it to work was using an encryption class of
mine and a php command line script. The mycrpt command line just didn't get it
right. Here is what I did

<?php
$key = 'test';
$data[] = 'abcdefghijklmnopqrstuvwxyz';
$m = 0;
class encrypt_class{
var $secret;
function encrypt_class(){
$this->secret = 'test';
}
Function encode($id){
$eid = $iv = 0;
$len = strlen($id);
$id = $len.'-'.$id;
$td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, "");
$key = substr($this->secret, 0, mcrypt_enc_get_key_size ($td));
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
mcrypt_generic_init ($td, $key, $iv);
$eid = base64_encode(mcrypt_generic ($td, $id));
mcrypt_generic_deinit($td);
return $eid;
}
Function decode($eid){
$id = $iv = 0;
$td = mcrypt_module_open (MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, "");
$key = substr($this->secret, 0, mcrypt_enc_get_key_size ($td));
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
mcrypt_generic_init ($td, $key, $iv);
$id = mdecrypt_generic ($td, base64_decode($eid));
$len = strtok($id,'-');
$id = substr($id,(strlen($len)+1),$len);
mcrypt_generic_deinit($td);
return $id;
}
}
$code = new encrypt_class();
foreach ($data as $dt)
{

$CRYPT[$m] = $code->encode($dt);


$DECRYPT[$m] = $code->decode($CRYPT[$m]);

echo "crypt_".$CRYPT[$m]."_<br />\n";
echo "decrypt_".$DECRYPT[$m]."_<br />\n";

$m++;
}
?>

shell script decode.php 'encrypted string'

#!/usr/bin/php
<?
Function decode($eid){
$secret = 'test';
$id = $iv = 0;
$td = mcrypt_module_open (MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, "");
$key = substr($secret, 0, mcrypt_enc_get_key_size ($td));
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
mcrypt_generic_init ($td, $key, $iv);
$id = mdecrypt_generic ($td, base64_decode($eid));
$len = strtok($id,'-');
$id = substr($id,(strlen($len)+1),$len);
mcrypt_generic_deinit($td);
return $id;
}
echo decode($argv[1])
?>




--
regards,
Tom