mauricelambert/rc6encryption

This package implements the RC6 encryption.

rc6encryption's Issues

bug when generating L list

Extracted from wiki:

L is initially a c-length list of 0-valued w-length words
for i = b-1 down to 0 do:
L[i/u] = (L[i/u] << 8) + K[i]

Which means:

L[3]= k[15]k[14]k[13]k[12]
L[2]= k[11]k[10]k[9]k[8]
L[1]= k[7]k[6]k[5]k[4]
L[0]= k[3]k[2]k[1]k[0]

One modification plan:

#block = f"{block}{bin(char)[2:]:0>8}"
block = f"{bin(char)[2:]:0>8}{block}"

#self.key_integer_reverse_blocks.reverse()
self.key_integer_reverse_blocks

Bug in key expansion

Key expansion pseudo code: https://en.wikipedia.org/wiki/RC5#Key_expansion (RC5 and RC6 share key expansion)

Note the line: do 3 * max(t, c) times:

Compare with https://github.com/mauricelambert/RC6Encryption/blob/main/RC6Encryption.py#L235-L239

but it should be

v = 3 * (
            self.key_blocks_number
            if self.key_blocks_number > self.round2_4
            else self.round2_4
        )

i.e. the multiplication by three should be on the outside of the expression.