ARC4(?) File Encryption

[xcoder]

Print "#################################"

'Same program code for encrypltion and decryption

code$="AAE1E2E3FF" 'hex$

for i = 1 to len(code$)step 2

chunk$ = mid$(code$,i,2)

print chunk$,

byte = hexDec(chunk$)

print byte

key$ = key$ + chr$(byte)

next i



input "File to read: ";file$

input "File to write: ";file2$

open file$ for input as #1

open file2$ for output as #2



msg$ = input$(#1,lof(#1))

a$ = PRGA$(msg$,key$)

print #2,a$;

close #1

close #2

for i = 1 to 6

print space$(i);"Processing"

next





print "------------------End of File ---------------------"



print:print

print "End of Code"

End



function PRGA$(msg$,key$)

dim S(256)

dim K(256)

i = 0

j = 0

for i=0 to 255

S(i)= i

next i

print ""

for i = 0 to 255

K(i)= asc(mid$(key$,i mod len(key$)+1))

next i

for i = 0 to 255

j = (j+ S(i)+ K(i))mod 256

temp = S(i)

S(i)= S(j)

S(j)= temp

next i

'-------------------------------------------------

i = 0

j = 0

for x = 1 to len(msg$)

byte = asc(mid$(msg$,x,1)) 'cannot use i nor j

j = (j + S(i))mod 256

temp = S(i)

S(i) = S(j)

S(j) = temp

k = (S(i) + S(j))mod 256

cipher = byte xor k

ascii$ = ascii$ + chr$(cipher)

next x

PRGA$ = ascii$

end function