improving present

[arm-crypto-lib.git] / des / des.c

diff --git a/des/des.c b/des/des.c
index f7b99526fa15bf97984e303e81320074f0b5255d..5ad65948eda6e166bcbeccfb14eacf9ab49b5411 100644 (file)
--- a/des/des.c
+++ b/des/des.c
@@ -202,10 +202,9 @@ const uint8_t shiftkeyinv_permtab[] = {
 #define ROTTABLE_INV  0x3F7E
 /******************************************************************************/
 
-void permute(uint8_t *ptable, const uint8_t *in, uint8_t *out){
-       uint8_t ib, ob; /* in-bytes and out-bytes */
+void permute(const uint8_t *ptable, const uint8_t *in, uint8_t *out){
+       uint8_t ob; /* in-bytes and out-bytes */
        uint8_t byte, bit; /* counter for bit and byte */
-       ib = ptable[0];
        ob = ptable[1];
        ptable = &(ptable[2]);
        for(byte=0; byte<ob; ++byte){
@@ -298,13 +297,17 @@ uint32_t des_f(uint32_t r, uint8_t* kr){
 /******************************************************************************/
 
 void des_enc(void* out, const void* in, const void* key){
-#define R *((uint32_t*)&(data[4]))
-#define L *((uint32_t*)&(data[0]))
+#define R (data.v32[1])
+#define L (data.v32[0])
 
-       uint8_t data[8],kr[6],k[7];
+       uint8_t kr[6],k[7];
        uint8_t i;
+       union {
+               uint8_t v8[8];
+               uint32_t v32[2];
+       } data;
        
-       permute((uint8_t*)ip_permtab, (uint8_t*)in, data);
+       permute((uint8_t*)ip_permtab, (uint8_t*)in, data.v8);
        permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);
        for(i=0; i<8; ++i){
                shiftkey(k);
@@ -324,19 +327,19 @@ void des_enc(void* out, const void* in, const void* key){
        R ^= L;
        L ^= R;
        R ^= L;
-       
-       permute((uint8_t*)inv_ip_permtab, data, (uint8_t*)out);
+       permute((uint8_t*)inv_ip_permtab, data.v8, (uint8_t*)out);
 }
 
 /******************************************************************************/
 
 void des_dec(void* out, const void* in, const uint8_t* key){
-#define R *((uint32_t*)&(data[4]))
-#define L *((uint32_t*)&(data[0]))
-
-       uint8_t data[8],kr[6],k[7];
+       uint8_t kr[6],k[7];
+       union {
+               uint8_t v8[8];
+               uint32_t v32[2];
+       } data;
        int8_t i;
-       permute((uint8_t*)ip_permtab, (uint8_t*)in, data);
+       permute((uint8_t*)ip_permtab, (uint8_t*)in, data.v8);
        permute((uint8_t*)pc1_permtab, (const uint8_t*)key, k);
        for(i=7; i>=0; --i){
                
@@ -359,8 +362,7 @@ void des_dec(void* out, const void* in, const uint8_t* key){
        R ^= L;
        L ^= R;
        R ^= L;
-       
-       permute((uint8_t*)inv_ip_permtab, data, (uint8_t*)out);
+       permute((uint8_t*)inv_ip_permtab, data.v8, (uint8_t*)out);
 }
 
 /******************************************************************************/