こんらんするな
$ php -a php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td)); 32 php > print_r(mcrypt_enc_get_block_size($td)); 16 php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_192, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td)); 32 php > print_r(mcrypt_enc_get_block_size($td)); 24 php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td)); 32 php > print_r(mcrypt_enc_get_block_size($td)); 32
すこしわかりやすく
php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td) * 8); 256 php > print_r(mcrypt_enc_get_block_size($td) * 8); 128 php > php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_192, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td) * 8); 256 php > print_r(mcrypt_enc_get_block_size($td) * 8); 192 php > php > $td = mcrypt_module_open(MCRYPT_RIJNDAEL_256, '', MCRYPT_MODE_CBC, ''); php > print_r(mcrypt_enc_get_key_size($td) * 8); 256 php > print_r(mcrypt_enc_get_block_size($td) * 8); 256
MCRYPT_RIJNDAELについて、ブロックの長さは選べるけど、鍵の長さは256bit固定なのね