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;----------------------------------------------------------------------------; ; RC4 CipherSaber in a chip V1.0 beta ; ; low level layer Protocol ; ;----------------------------------------------------------------------------; ;*************************************************************************** ; ; AT90S8515Px ; SIGNAL_NAME ______ ______ SIGNAL_NAME ; . | - | . ; . --> (TO) PB0 --| 1 40 |-- VCC . ; . --> (T1) PB1 --| 2 39 |-- PA0 (AD0) <-> . ; . --> (AIN0) PB2 --| 3 38 |-- PA1 (AD1) <-> . ; . --> (AIN1) PB3 --| 4 37 |-- PA2 (AD2) <-> . ; . --> (SS*) PB4 --| 5 36 |-- PA3 (AD3) <-> . ; . <-- (MOSI) PB5 --| 6 35 |-- PA4 (AD4) <-> . ; . --> (MISO) PB6 --| 7 34 |-- PA5 (AD5) <-> . ; . <-- (SCK) PB7 --| 8 33 |-- PA6 (AD6) <-> . ; . --> RESET* ->| 9 32 |-- PA7 (AD7) <-> . ;rs 232. --> (RXD) PD0 --| 10 31 |-- ICP <-- . ;rs 232. <-- (TXD) PD1 --| 11 30 |-- ALE --> . ; . --> (INT0) PD2 --| 12 29 |-- OC1B --> . ; . --> (INT1) PD3 --| 13 28 |-- PC7 (A15) --> . ; . <-> PD4 --| 14 27 |-- PC6 (A14) --> . ; . <-- (OC1A) PD5 --| 15 26 |-- PC5 (A13) --> . ; . <-- (WR*) PD6 --| 16 25 |-- PC4 (A12) --> . ; . <-- (RD*) PD7 --| 17 24 |-- PC3 (A11) --> . ; . --> XTAL1 ->| 18 23 |-- PC2 (A10) --> . ; . <-- XTAL2 <-| 19 22 |-- PC1 (A9) --> . ; GND --| 20 21 |-- PC0 (A8) --> . ; |_____________| ; ; (DIP-40) ; ;*************************************************************************** ;*Algorithm RC4 CipherSaber by Ron Rivest of RSA Security ;*************************************************************************** ;S-array is initialized whiy s0=0 ,s1=1 ,s2=2 ,s3=3, ,,,s255=255 ;k-array is initialized whit PassPhrase + 10 ramdom bytes (mod key_leng) ;*************************************************************************** ;* Definitions ;*************************************************************************** .include "c:\atmel\inc\8515def.inc";Define chip particulars ;***** Global register variables .def temp = R16 .def key_length = r17 .def Ath = r18 ;adresse pointer .def Bth = r19 ;adresse pointer .def Nth = r20 ;adresse pointer .def a = r21 .def b = r22 .def n = r23 .def temp2 = r24 .def loop_255 = r25 .equ S_array = $60 .equ k_array = $160 .cseg ; Interrupt vectors .org 0 rjmp reset ;Reset Vector ;*************************************************************************** ;* reset ;*************************************************************************** ; Main program entry point on reset reset: ldi temp,low(RAMEND) out SPL,temp ;init Stack Pointer ldi temp,high(RAMEND) out SPH,temp ldi YH,high(S_array) ldi YL,low(S_array) ;init Y-pointer ldi temp,0 ;*************************************************************************** ;* initialization of S array (key for Encryption) ;*************************************************************************** ini_s: st Y+,temp ;start of ini of S_array inc temp brne ini_s ;end of ini of S_arry ;*************************************************************************** ;* initialization of k array (PassPhrase) ;*************************************************************************** ldi temp,0 ldi YH,high(k_array) ldi YL,low(k_array);init Y-pointer ini_K_loop: ldi ZH,high(key*2) ldi ZL,low(key*2);init Z-pointer ldi key_length,56 ini_k: lpm ;get constant st Y+,r0 ;store in SRAM and increment Y-pointer adiw ZL,1 ;increment Z-pointer dec key_length brne ini_k ;*************************************************************************** ;* Generation of Pseudo-Random Stream ;*************************************************************************** ramdom: ldi loop_255,255 ldi key_length,15 ldi n,0 ldi a,0 ldi b,0 ldi ath,0 ldi nth,0 ldi bth,0 s0: ldi YH,high(k_array) ldi YL,low(k_array) ;init Y-pointer ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer s1: cp a,ath ;check if poiter is a desired position breq s1_out ;if yes go load memory location inc a ;if no ok not bad just add a adiw r28,1 ;dont forget to add memory pointer rjmp s1 ;now is time to make a other ride s1_out: ld a,y k1: cp n,nth ;check if poiter is a desired position breq k1_out ;if yes go load memory location inc n ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp k1 ;now is time to make a other ride k1_out: ld n,z add a,n ;(a+n) add b,a ;b=(a+n+b) add bth,a ;bth=(a+n+b) b adress pointer ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi N,0 s2: cp N,Nth ;check if poiter is a desired position breq s2_out ;if yes go load memory location inc N ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp s2 ;now is time to make a other ride s2_out: ld temp,z ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi B,0 s3: cp B,Bth ;check if poiter is a desired position breq s3_out ;if yes go load memory location inc B ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp s3 ;now is time to make a other ride s3_out: ld temp2,z st z,temp ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi N,0 s4: cp N,Nth ;check if poiter is a desired position breq s4_out ;if yes go load memory location inc N ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp s4 ;now is time to make a other ride s4_out: st z,temp2 ldi a,0 ldi n,0 inc ath inc nth cp nth,loop_255 breq xor cp ath,key_length breq mod_key rjmp s0 ; rjmp xor mod_key: ldi ath,0 rjmp s0 ;*************************************************************************** ;* now is time to scramble the data (the proff of your are guilty) ;*************************************************************************** xor: ldi n,0 ; ldi a,0 ldi b,0 ldi ath,0 ldi nth,0 ldi bth,0 encryp: ldi ZH,high(s_array) ldi ZL,low(s_array) ldi A,0 inc ath e1: cp a,ath ;check if poiter is a desired position breq e1_out ;if yes go load memory location inc a ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp e1 ;now is time to make a other ride E1_out: ld a,z add bth,a ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi A,0 E2: cp A,Ath ;check if poiter is a desired position breq E2_out ;if yes go load memory location inc A ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp E2 ;now is time to make a other ride E2_out: ld temp,z ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi B,0 E3: cp B,Bth ;check if poiter is a desired position breq E3_out ;if yes go load memory location inc B ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp E3 ;now is time to make a other ride E3_out: ld temp2,z st z,temp ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi A,0 E4: cp A,Ath ;check if poiter is a desired position breq E4_out ;if yes go load memory location inc A ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp E4 ;now is time to make a other ride E4_out: st z,temp2 add temp2,temp add nth,temp2 ldi ZH,high(s_array) ldi ZL,low(s_array) ;init Z-pointer ldi n,0 E5: cp N,Nth ;check if poiter is a desired position breq E5_out ;if yes go load memory location inc N ;if no ok not bad just add a adiw r30,1 ;dont forget to add memory pointer rjmp E5 ;now is time to make a other ride E5_out: ld N,z ldi nth,0 byte_xor: ; eor n,data end: rjmp encryp key: .db "this is the test passphrase using for test",0 |