LOWERCASE HTTP SCRAMBLE

REPORT  Z_LOWERCASE_HTTP_SCRAMBLE.
data: conv type ref to cl_abap_conv_out_ce,
buffer type xstring,
x4(4) type x,
y4(4) type x,
x type x,
i type i,
mask(4) type x value '0000003F',
dest(100) type x,
lf type f.


data: stab(64) type x value
'F0ED53B83244F1F876C67959FD4F13A2' &
'C15195EC5483C234774943A27DE26596' &
'5E5398789A17A33CD383A8B829FBDCA5' &
'55D702778413ACDDF9B83116610E6DFA'.
data: sourcelen type i,
key       type i,
source    type string,
destination type c LENGTH 100.
sourcelen = 5.
key = 26101957.
source = 'sifre'.


if sourcelen eq 0. exit. endif.


y4 = key.
x4 = key * 2.
y4 = y4 bit-xor x4.
x4 = key / 32.
y4 = y4 bit-xor x4.
y4 = y4 bit-and mask.


conv = cl_abap_conv_out_ce=>create( encoding = 'UTF-8' ).
call method conv->write( data = source ).
buffer = conv->get_buffer( ).


i = 0.
do sourcelen times.
if sy-index eq 40.
x4 = 1.
endif.
lf = ( key * i * i - i ) mod 256.
x = lf.
x = stab+y4(1) bit-xor x.
dest+i = buffer+i(1) bit-xor x.
i = i + 1.
y4 = y4 + 1.
y4 = y4 bit-and mask.
enddo.


write dest(sourcelen) to destination.
write destination.