+DES/3DES

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

diff --git a/seed-asm.S b/seed-asm.S
new file mode 100644 (file)
index 0000000..3f757d8
--- /dev/null
+++ b/seed-asm.S
@@ -0,0 +1,90 @@
+/**
+ * \file       seed-asm.S
+ * \author     Daniel Otte 
+ * \date       2007-06-1
+ * \brief      SEED parts in assembler for AVR
+ * \par License        
+ * GPL
+ * 
+ */
+SPL = 0x3D
+SPH = 0x3E
+SREG = 0x3F
+
+
+/*******************************************************************************
+
+       void changeendian32(uint32_t * a){
+               *a = (*a & 0x000000FF) << 24 |
+                        (*a & 0x0000FF00) <<  8 |
+                        (*a & 0x00FF0000) >>  8 |
+                        (*a & 0xFF000000) >> 24;
+       }
+
+*/
+/*
+.global changeendian32
+; === change_endian32 ===
+; function that changes the endianess of a 32-bit word
+;  param1: the 32-bit word
+;      given in r25,r24,r23,22 (r25 is most significant)
+;  modifys: r21, r22
+changeendian32:
+       movw r20,  r22 ; (r22,r23) --> (r20,r21)
+       mov r22, r25
+       mov r23, r24
+       mov r24, r21
+       mov r25, r20 
+       ret
+
+*/
+
+/*******************************************************************************
+       uint32_t bigendian_sum32(uint32_t a, uint32_t b){
+               changeendian32(&a);
+               changeendian32(&b);
+               a += b;
+               changeendian32(&a);
+               return a;
+       }
+*/
+
+.global bigendian_sum32
+; === bigendian_sum32 ===
+; function that adds two 32-bit words in the bigendian way and returns the result
+;  param1: the first 32-bit word
+;      given in r25,r24,r23,22 (r25 is most significant for little endian)
+;  param2: the second 32-bit word
+;      given in r21,r20,r19,18 (r21 is most significant for little endian)
+;  modifys: 
+bigendian_sum32:
+       add r25, r21
+       adc r24, r20
+       adc r23, r19
+       adc r22, r18
+       ret
+       
+.global bigendian_sub32
+; === bigendian_sub32 ===
+; function that subtracts a 32-bit words from another in the bigendian way and returns the result
+;  param1: the minuend 32-bit word
+;      given in r25,r24,r23,22 (r25 is most significant for little endian)
+;  param2: the subtrahend 32-bit word
+;      given in r21,r20,r19,18 (r21 is most significant for little endian)
+;  modifys: 
+bigendian_sub32:
+       sub r25, r21
+       sbc r24, r20
+       sbc r23, r19
+       sbc r22, r18
+       ret
+       
+
+
+
+
+
+
+
+
+       
\ No newline at end of file