Re: PHP to decode AES

On Oct 18, 2012, at 4:39 PM, Adam Richardson <simpleshot@gmail.com> wrote: > On Thu, Oct 18, 2012 at 12:06 PM, Rick Dwyer <rpdwyer@earthlink.net> wrote: >> Hello all. >> >> Has anyone ever tried to decode a JAVA AES/CBC encrypted string with PHP before? >> >> I found a tutorial online with the following code to use as starting point, but it fails to >> return anything readable: >> >> $code ='Hello World'; >> $key = 'my key'; >> >> function decrypt($code, $key) { >> $key = hex2bin($key); >> $code = hex2bin($code); >> $td = mcrypt_module_open("rijndael-128", "", "cbc", >> ""); >> mcrypt_generic_init($td, $key, "fedcba9876543210"); >> $decrypted = mdecrypt_generic($td, $code); >> mcrypt_generic_deinit($td); >> mcrypt_module_close($td); >> return utf8_encode(trim($decrypted)); >> } >> >> >> function hex2bin($hexdata) { >> $bindata = ""; >> for ($i = 0; $i < strlen($hexdata); $i += 2) { >> $bindata .= chr(hexdec(substr($hexdata, $i, 2))); >> } >> return $bindata; >> } >> echo decrypt($code, $key); >> >> The above returns output containing a series of unprintable characters. >> >> I thought maybe it was due to $code not being in a hex format, but after converting to hex >> and resubmitting, I still unprintable characters. >> >> Any info is appreciated. > > Can you post the Java code you're using? There are things such as the > padding specification that could cause some issues. > > Adam > Hi all. We were able to get it to work. But thank you for your replies. But for anyone interested (including anyone who has emailed me privately implying I was up to something untoward), the specs from the client were as follows: Unencrypted: "2012-10-18T10:57:43+0200 someurl.com" Encrypted + base64: "ch7WvaSrCiHLstNeNUp5SkPfPGqZ8vrNPJT+9vU7jN/C" Encrypt algorithm: AES/CBC, PKCS5Padding, IV of 16 NULL (0x0 hex) bytes Key: "someKEY123-12346" -------------------------------------------------------------------------------------------------------------------- $iv = mcrypt_create_iv(32); $key = 'someKEY123-12346'; $text = '2012-10-18T10:57:43+0200 someurl.com'; $size = mcrypt_get_block_size('rijndael-128', 'cbc'); $text = pkcs5_pad($text, $size); $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $text, MCRYPT_MODE_CBC, $iv); $decrypttext = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, base64_decode('ch7WvaSrCiHLstNeNUp5SkPfPGqZ8vrNPJT+9vU7jN/C'), MCRYPT_MODE_CBC, $iv); function pkcs5_pad ($text, $blocksize) { $pad = $blocksize - (strlen($text) % $blocksize); return $text . str_repeat(chr($pad), $pad); } echo $decrypttext; …