possible rijndael bug

[lg]

Hello hackers.

I recently examined rijndael implementation, which ships in sys/crypto/rijndael and there
is code in function rijndael_padEncrypt()(from rijndael-api-fst.c):

numBlocks = inputOctets/16;
...
...
padLen = 16 - (inputOctets - 16*numBlocks);
if (padLen > 0 && padLen <= 16)
        panic("...");
bcopy(input, block, 16 - padLen);
for (cp = block + 16 - padLen; cp < block + 16; cp++)
	*cp = padLen;
rijndaelEncrypt(block, outBuffer, key->keySched, key->ROUNDS);
...

so padLen check will always success and it surely will panic, or even if we admit that 
padLen check is bypassed(what is impossible i think) then bcopy() will be called with 
larger size argument then size of block array or with negative size. Isn't this padLen 
check is unneeded? or maybe it should look like 'if (padLen <= 0 || padLen > 16)'?

In RFC2040 there is a description about how to process last block and there is not such 
checks.