PureBasic Forums - English

moricode wrote: Mon Jan 20, 2025 8:05 amyou could even make it smaller by using only one procedure to encrypt and decrypt , they are same actually.

Procedure dec(buf,size)
  ProcedureReturn enc(buf,size)
EndProcedure

moricode wrote: Mon Jan 20, 2025 8:05 am you do not need a super complex world class security encryption for your simple office daily application's ,
unless you are working with the Pentagon .

for other case ,you can try this super easy , super fast tiny encryption method for some good medium security .

1. On line 15, you re-allocate the memory "buf" to be a multiple of 4. However, "size + n" with "n=size%4" does not align on 4! If size is 5, n calculates to 1 and size+n become 6.
2. Further, ReAllocateMemory requier a memory address created by AllocateMemory. The code crashes when "buf" is a different address.
3. On line 18, you set "*n=buf" if the buffer can't be re-allocated. That doesn't make sense, does it, because then you forgot to encrypt the last bytes.

NicTheQuick wrote: Wed Jan 22, 2025 12:15 pm Sorry, but that's bullshit. Either you use proper encryption or you don't. There is nothing in between. Why do you want to tell people here that they only need such cheap encryption for their stuff?

Caronte3D wrote: Wed Jan 22, 2025 2:36 pm Even if you intention was nice, with PB is very easy to use a good encryption method, so... IMHO, no need to use worse ones

STARGÅTE wrote: Thu Jan 23, 2025 2:11 pm @moricode:

Your code has some bugs:

1. On line 15, you re-allocate the memory "buf" to be a multiple of 4. However, "size + n" with "n=size%4" does not align on 4! If size is 5, n calculates to 1 and size+n become 6.
2. Further, ReAllocateMemory requier a memory address created by AllocateMemory. The code crashes when "buf" is a different address.
3. On line 18, you set "*n=buf" if the buffer can't be re-allocated. That doesn't make sense, does it, because then you forgot to encrypt the last bytes.

Nevertheless, I agree with NicTheQuick. Either you use a real encryption on nothing at all. And why do you thing. Further, I doubt that your encryption is "super fast", because typical encryption algorithms are nowadays implemented on hardware level:https://en.wikipedia.org/wiki/AES_instruction_set

Structure key 
   k.b[0]
EndStructure
DataSection
   key:
   Data.i $ABCDEFAB,$9876BCDE,$dcbaafe0  ; xor multiple loop with 3 key , key = 4 byte
EndDataSection

Global *key.key
*key = ?key

Procedure New_Enc_Dec(buf,size)
   b= size
   For i = 0 To 2
      b -1
      For p=0 To b
         key = *key\k[i]
         IF p%2
            key!*key\k[i+1]
         ENDIF
         j=buf+p
         PokeB(j,PeekB(j)!key)
      Next 
   Next
   ProcedureReturn buf
EndProcedure

; --------------------------------------------
; Example use: 
A$="The quick brown fox jumps over the lazy dog 12 times a day"
L=Len(A$)<<1+2
*u=AllocateMemory(200)
PokeS(*u,A$)
Debug PeekS(*u)
Debug "---- Encrypted ----"
Encrypt = New_Enc_dec(*u, L )

Debug PeekS( Encrypt)
Debug "----Decrypted ----"

Decrypt = New_Enc_Dec(*u, L )
Debug PeekS(Decrypt,L)

1. On line 15, "b -1", you decrease the loop limit each round by one byte. So the latter bytes are encrypted just one or two rounds, not three.
2. The "key" structure is now a byte array and as your round-loop has only three rounds (plus an extra byte) you use only 4 bytes of your 12 bytes key!
3. What is the sense of line 18-20, where you change the key itself, when the byte position is odd?

moricode wrote: Fri Jan 24, 2025 2:57 am

NicTheQuick wrote: Wed Jan 22, 2025 12:15 pm Sorry, but that's bullshit. Either you use proper encryption or you don't. There is nothing in between. Why do you want to tell people here that they only need such cheap encryption for their stuff?

dose forum means user can have difference idea and more discuss on variant code method ?
and some body can correct the bugs and raise more better code and more people can learn from insight from codes that never seen before ?

does we need brain storming ?

do you allow the chicken to grow up when it is still in the egg grader ?

what do you think ?

silent the junior user to bring up idea ?

Sorry , and with my million apologize .