*/
#include <avr/io.h>
-
-/*******************************************************************************
-* MACRO SECTION *
-*******************************************************************************/
-
-.macro push_ p1:req, p2:vararg
- push \p1
-.ifnb \p2
- push_ \p2
-.endif
-.endm
-
-.macro pop_ p1:req, p2:vararg
- pop \p1
-.ifnb \p2
- pop_ \p2
-.endif
-.endm
-
-.macro push_range from:req, to:req
- push \from
-.if \to-\from
- push_range "(\from+1)",\to
-.endif
-.endm
-
-.macro pop_range from:req, to:req
- pop \to
-.if \to-\from
- pop_range \from,"(\to-1)"
-.endif
-.endm
-
-.macro stack_alloc size:req, reg1=r30, reg2=r31
- in r0, _SFR_IO_ADDR(SREG)
- cli
- in \reg1, _SFR_IO_ADDR(SPL)
- in \reg2, _SFR_IO_ADDR(SPH)
- sbiw \reg1, \size
- out _SFR_IO_ADDR(SPH), \reg2
- out _SFR_IO_ADDR(SPL), \reg1
- out _SFR_IO_ADDR(SREG), r0
-.endm
-
-.macro stack_free size:req, reg1=r30, reg2=r31
- in r0, _SFR_IO_ADDR(SREG)
- cli
- in \reg1, _SFR_IO_ADDR(SPL)
- in \reg2, _SFR_IO_ADDR(SPH)
- adiw \reg1, \size
- out _SFR_IO_ADDR(SPH), \reg2
- out _SFR_IO_ADDR(SPL), \reg1
- out _SFR_IO_ADDR(SREG), r0
-.endm
-
-/*******************************************************************************
-* END of MACRO SECTION *
-*******************************************************************************/
+#include "avr-asm-macros.S"
/*
static void serpent_lt(uint8_t *b){
T2 = 22
T3 = 23
-.global serpent_lt
serpent_lt:
push_range 4, 17
movw r26, r24
pop_range 4, 17
ret
-
#endif
+
T0 = 22
T1 = 23
T2 = 24
brne 1b
ret
-.global serpent_lt
serpent_lt:
/* X0 := X0 <<< 13 */
movw r26, r24
rcall memrotr32
ret
-.global serpent_inv_lt
serpent_inv_lt:
/* X0 := X0 >>> 5 */
movw r26, r24
/* trashes:
* r20-r25, r30-r31
*/
-.global serpent_gen_w
serpent_gen_w:
movw r30, r24
/* ^i^b[0]*/
stack_free 32
ret
+/*
+ * void serpent_enc(void* buffer, const serpent_ctx_t* ctx){
+ */
+/*
+ * param buffer is passed in r24:r25
+ * param ctx is passed in r22:r23
+ */
+.global serpent_enc
+serpent_enc:
+ push_ r12, r13, r14, r15, r16
+ clr r16
+ movw r14, r24
+ movw r12, r22
+1:
+ movw r24, r14
+ movw r22, r12
+ ldi r20, 16
+ add r12, r20
+ adc r13, r1
+ clr r21
+ rcall memxor
+ movw r24, r14
+ mov r22, r16
+ rcall sbox128
+ movw r24, r14
+ rcall serpent_lt
+
+ inc r16
+ cpi r16, 31
+ brne 1b
+
+ movw r24, r14
+ movw r22, r12
+ ldi r20, 16
+ add r12, r20
+ adc r13, r1
+ clr r21
+ rcall memxor
+ movw r24, r14
+ mov r22, r16
+ rcall sbox128
+
+ inc r16
+ movw r24, r14
+ movw r22, r12
+ ldi r20, 16
+ clr r21
+ pop_ r16, r15, r14, r13, r12
+ rjmp memxor
+
+/*
+ * void serpent_dec(void* buffer, const serpent_ctx_t* ctx){
+ */
+/*
+ * param buffer is passed in r24:r25
+ * param ctx is passed in r22:r23
+ */
+.global serpent_dec
+serpent_dec:
+ push_ r12, r13, r14, r15, r16
+ movw r14, r24
+// ldi r16, lo8(32*16)
+// add r22, r16
+ ldi r16, hi8(32*16)
+ add r23, r16
+ movw r12, r22
+ ldi r20, 16
+ clr r21
+ rcall memxor
+
+ movw r24, r14
+ ldi r22, 31
+ rcall inv_sbox128
+
+ movw r24, r14
+ ldi r20, 16
+ sub r12, r20
+ sbc r13, r1
+ movw r22, r12
+ clr r21
+ rcall memxor
+ ldi r16, 31
+1:
+ dec r16
+ movw r24, r14
+ rcall serpent_inv_lt
+ movw r24, r14
+ mov r22, r16
+ rcall inv_sbox128
+ movw r24, r14
+ ldi r20, 16
+ sub r12, r20
+ sbc r13, r1
+ movw r22, r12
+ clr r21
+ rcall memxor
+
+ tst r16
+ brne 1b
+ pop_ r16, r15, r14, r13, r12
+ ret
+
+
+