finished asm version of serpent (may be optimized later)

[avr-crypto-lib.git] / serpent-asm.S

diff --git a/serpent-asm.S b/serpent-asm.S
index 1005fd368b56ac1ceed0735ba90d3e172668cd52..56c5dd038888d6d5fa05b8d5f6896d0616cb41b7 100644 (file)
--- a/serpent-asm.S
+++ b/serpent-asm.S
@@ -123,7 +123,6 @@ T1 = 21
 T2 = 22
 T3 = 23
 
-.global serpent_lt
 serpent_lt:
        push_range 4, 17
        movw r26, r24
@@ -278,8 +277,8 @@ serpent_lt:
        
        pop_range 4, 17
        ret
-
 #endif
+
 T0 = 22
 T1 = 23
 T2 = 24
@@ -339,7 +338,6 @@ memeor32:
   brne 1b
   ret
 
-.global serpent_lt
 serpent_lt:
         /* X0 := X0 <<< 13 */
        movw r26, r24
@@ -432,7 +430,6 @@ serpent_lt:
        rcall memrotr32
        ret
 
-.global serpent_inv_lt
 serpent_inv_lt:
         /* X0 := X0 >>> 5 */
        movw r26, r24
@@ -541,7 +538,6 @@ static uint32_t serpent_gen_w(uint32_t * b, uint8_t i){
  /* trashes:
   *  r20-r25, r30-r31
   */
-.global serpent_gen_w
 serpent_gen_w:
        movw r30, r24
        /* ^i^b[0]*/
@@ -694,7 +690,111 @@ serpent_init:
        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     
+       
+       
+