DES encryption in PHP
I am coding a Drupal payment method module and within this I need to generate a hash to send to a bank. Bank asks me to code certain strings into the DES/ECB hash. They also provide test environment and here comes my problem. With the string B7DC02D5D6F2689E and key 7465737465703031 I should get result hash 3627C7356B25922B (after bin2hex, of course). This is by the bank test page and I have also checked this on this page: http://www.riscure.com/tech-corner/online-crypto-tools/des.html (encryption java applet).
My problem is that whatever I do I cant get my PHP code to provide the correct result. This is a simple function I am trying to use:
function encrypt($hash, $key)
{
$hash = strtoupper(substr(sha1($hash), 0, 16));
$key = strtoupper(bin2hex($key));
$block = mcrypt_get_block_size('des', 'ecb');
if (($pad = $block - (strlen($hash) % $block)) < $block) {
$hash .= str_repeat(chr($pad), $pad);
}
$sig = strtoupper(bin2hex(mcrypt_encrypt(MCRYPT_DES, $key, $hash, MCRYPT_MODE_ECB)));
return $sig;
}
and I have been trying sth like this as well:
function encrypt( $value, $key) {
$hash = strtoupper(substr(sha1($value), 0, 16));
$key = strtoupper(substr(bin2hex($key), 0, 16));
// encrypt hash with key
if (function_exists('mcrypt_module_open')) { // We have mcrypt 2.4.x
$td = mcrypt_module_open(MCRYPT_DES, "", MCRYPT_MODE_ECB, "");
$iv = mcrypt_create_iv(mcrypt_enc_get_iv_size ($td), MCRYPT_RAND);
mcrypt_generic_init($td, $key, $iv);
$signature = strtoupper(bin2hex(mcrypt_generic ($td, $hash)));
mcrypt_generic_end ($td);
}
else
{ // We have 2.2.x only
$signature = strtoupper(bin2hex(mcrypt_ecb (MCRYPT_3DES, $key, $hash, MCRYPT_ENCRYPT)));
}
return $signature;
}
None of these gave the correct signature. Any idea what's wrong? For now I am dealing with this issue more than 3 hrs, so I appreciate any help. I am not very familiar with this encryption stuff. Thanks a lot.
Btw.: Those $hash and $key mentioned above 开发者_如何转开发are after the strtoupper, substr and bin2hex functions at the beginning of my code snippets.
Simple solution:
function encrypt($hash, $key) {
return mcrypt_encrypt("des", pack("H*", $key), pack("H*", $hash), "ecb");
}
print bin2hex(encrypt("B7DC02D5D6F2689E", "7465737465703031"));
This prints 3627c7356b25922b
for me, so it looks like that's working.
You were on the right track with bin2hex()
, but that was converting in the wrong direction. (There's unfortunately no hex2bin()
function, so you have to use pack()
instead.)
You also don't need an IV for a single-block encryption like this.
You plaintext, B7DC02D5D6F2689E
, is 8 bytes = 64 bits. This is an exact block for DES so you don't need any padding in ECB mode. I suggest that you remove the padding code entirely. All DEC-ECB needs in this case is the block to encrypt and the key; no padding and no IV.
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