even more ASM-fun now only decryption needs C-Stub

diff --git a/seed-asm.S b/seed-asm.S
index 62d8420bfd47b26ccf44d5e6dc9e05449139c08f..9abad3f02cf2202c6f666f5eee29cd90915dceae 100644 (file)
--- a/seed-asm.S
+++ b/seed-asm.S
@@ -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
+
+
+
+

diff --git a/seed-stub.c b/seed-stub.c
index d31665ce2819dce8146bc91f93ed97ab658fb795..d9c22899399a856569d80d256fd36e75ad47df89 100644 (file)
--- a/seed-stub.c
+++ b/seed-stub.c
@@ -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){
 
 
 
-
-