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avr-crypto-lib
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even more ASM-fun now only decryption needs C-Stub

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bg 2008-12-11 17:46:12 +00:00
parent 20f6d949b7
commit fabad4ec56
2 changed files with 164 additions and 5 deletions
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164
seed-asm.S
View File

@ -477,7 +477,7 @@ seed_getnextkeys:
push_range 10, 17
push r28
push r29
andi r22, 0x0F
; andi r22, 0x0F
bst r22,0
rcall compute_keys
brtc even_round
@ -586,7 +586,7 @@ seed_getprevkeys:
push r28
push r29
movw r28, r24
andi r22, 0x0F
; andi r22, 0x0F
bst r22, 0
brts r_odd_round
r_even_round:
@ -676,3 +676,163 @@ seed_kc:
.long 0x8d676ede
.long 0x1bcfdcbc
/******************************************************************************/
/*
#define L (((uint64_t*)buffer)[0])
#define R (((uint64_t*)buffer)[1])
void seed_enc(void * buffer, seed_ctx_t * ctx){
uint8_t r;
keypair_t k;
for(r=0; r<8; ++r){
k = seed_getnextkeys(ctx->k, 2*r);
/ *
DEBUG_S("\r\n\tDBG ka,0: "); uart_hexdump(&k.k0, 4);
DEBUG_S("\r\n\tDBG ka,1: "); uart_hexdump(&k.k1, 4);
DEBUG_S("\r\n\t DBG L: "); uart_hexdump((uint8_t*)buffer+0, 8);
DEBUG_S("\r\n\t DBG R: "); uart_hexdump((uint8_t*)buffer+8, 8);
* /
L ^= seed_f_function(&R,k.k0,k.k1);
k = seed_getnextkeys(ctx->k, 2*r+1);
/ *
DEBUG_S("\r\n\tDBG kb,0: "); uart_hexdump(&k.k0, 4);
DEBUG_S("\r\n\tDBG kb,1: "); uart_hexdump(&k.k1, 4);
DEBUG_S("\r\n\t DBG L: "); uart_hexdump((uint8_t*)buffer+8, 8);
DEBUG_S("\r\n\t DBG R: "); uart_hexdump((uint8_t*)buffer+0, 8);
* /
R ^= seed_f_function(&L,k.k0,k.k1);
}
/ * just an exchange without temp. variable * /
L ^= R;
R ^= L;
L ^= R;
}
*/
/*
* param buffer: r24:r25
* param ctx: r22:r23
*/
CTR = 9
xLPTR = 10
xRPTR = 12
CPTR = 14
.global seed_enc
seed_enc:
push_range 9, 17
push r28
push r29
clr CTR
movw xLPTR, r24
adiw r24, 8
movw xRPTR, r24
movw CPTR, r22
1:
movw r28, xLPTR
movw r24, CPTR
mov r22, CTR
lsl r22
rcall seed_getnextkeys
/* use pen & paper to understand the following permutation */
movw r16, r22
movw r22, r18
movw r18, r24
movw r24, r20
movw r20, r22
movw r22, r24
movw r24, xRPTR
rcall seed_f_function
ld r0, Y
eor r0, r18
st Y+, r0
ld r0, Y
eor r0, r19
st Y+, r0
ld r0, Y
eor r0, r20
st Y+, r0
ld r0, Y
eor r0, r21
st Y+, r0
ld r0, Y
eor r0, r22
st Y+, r0
ld r0, Y
eor r0, r23
st Y+, r0
ld r0, Y
eor r0, r24
st Y+, r0
ld r0, Y
eor r0, r25
st Y+, r0
/* secound half */
movw r24, CPTR
mov r22, CTR
lsl r22
inc r22
rcall seed_getnextkeys
movw r16, r22
movw r22, r18
movw r18, r24
movw r24, r20
movw r20, r22
movw r22, r24
movw r24, xLPTR
rcall seed_f_function
ld r0, Y
eor r0, r18
st Y+, r0
ld r0, Y
eor r0, r19
st Y+, r0
ld r0, Y
eor r0, r20
st Y+, r0
ld r0, Y
eor r0, r21
st Y+, r0
ld r0, Y
eor r0, r22
st Y+, r0
ld r0, Y
eor r0, r23
st Y+, r0
ld r0, Y
eor r0, r24
st Y+, r0
ld r0, Y
eor r0, r25
st Y+, r0
inc CTR
bst CTR, 3
brts 3f
rjmp 1b
3:
movw r28, xLPTR
movw r30, xRPTR
ldi r17, 8
4:
ld r10, Y
ld r11, Z
st Z+, r10
st Y+, r11
dec r17
brne 4b
5:
pop r29
pop r28
pop_range 9, 17
ret

5
seed-stub.c
View File

@ -44,7 +44,7 @@ keypair_t seed_getnextkeys(uint32_t *keystate, uint8_t curround);
keypair_t seed_getprevkeys(uint32_t *keystate, uint8_t curround);
/******************************************************************************/
#if 0
#define L (((uint64_t*)buffer)[0])
#define R (((uint64_t*)buffer)[1])
@ -75,6 +75,7 @@ void seed_enc(void * buffer, seed_ctx_t * ctx){
R ^= L;
L ^= R;
}
#endif
/******************************************************************************/
@ -117,5 +118,3 @@ void seed_dec(void * buffer, seed_ctx_t * ctx){