adding RSA-OAEP

[avr-crypto-lib.git] / skipjack / skipjack.c

diff --git a/skipjack/skipjack.c b/skipjack/skipjack.c
index ec36edff403c4c826762ada4797b6057accf3ed3..0b432492f38bac1c64b14a60e6037a444d05f3fa 100644 (file)
--- a/skipjack/skipjack.c
+++ b/skipjack/skipjack.c
@@ -80,33 +80,40 @@ const uint8_t skipjack_ftable[] PROGMEM ={
 };
 
 /*****************************************************************************/
+static
+uint16_t skipjack_sub_g(uint8_t g, uint8_t k, uint8_t *key){
+       return pgm_read_byte(&(skipjack_ftable[g ^ key[9 - k % 10]]));
+}
 
+static
 uint16_t skipjack_g(uint16_t g, uint8_t k, uint8_t *key){
        #define G1 (((uint8_t*)&g)[1])
        #define G2 (((uint8_t*)&g)[0])
        /* this could also be rolled up */
-       G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[9-(4*k+0)%10]]));
-       G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[9-(4*k+1)%10]]));
-       G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[9-(4*k+2)%10]]));
-       G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[9-(4*k+3)%10]]));
+       k *= 4;
+       G1 ^= skipjack_sub_g(G2, k + 0, key);
+       G2 ^= skipjack_sub_g(G1, k + 1, key);
+       G1 ^= skipjack_sub_g(G2, k + 2, key);
+       G2 ^= skipjack_sub_g(G1, k + 3, key);
        return g;       
 }
 
 /*****************************************************************************/
-
+static
 uint16_t skipjack_g_inv(uint16_t g, uint8_t k, uint8_t *key){
 //     #define G1 (((uint8_t)&g)[1])
 //     #define G2 (((uint8_t)&g)[0])
        /* this could also be rolled up */
-       G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[9-(4*k+3)%10]]));
-       G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[9-(4*k+2)%10]]));
-       G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[9-(4*k+1)%10]]));
-       G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[9-(4*k+0)%10]]));
-       return g;       
+       k *= 4;
+       G2 ^= skipjack_sub_g(G1, k + 3, key);
+       G1 ^= skipjack_sub_g(G2, k + 2, key);
+       G2 ^= skipjack_sub_g(G1, k + 1, key);
+       G1 ^= skipjack_sub_g(G2, k + 0, key);
+       return g;
 }
 
 /*****************************************************************************/
-
+static
 void skipjack_a(uint16_t* w, uint8_t k, uint8_t* key){
        uint16_t t;
        t = w[0];
@@ -117,7 +124,7 @@ void skipjack_a(uint16_t* w, uint8_t k, uint8_t* key){
 }
 
 /*****************************************************************************/
-
+static
 void skipjack_a_inv(uint16_t* w, uint8_t k, uint8_t* key){
        uint16_t t;
        t = w[3] ^ w[2];
@@ -128,7 +135,7 @@ void skipjack_a_inv(uint16_t* w, uint8_t k, uint8_t* key){
 }
 
 /*****************************************************************************/
-
+static
 void skipjack_b(uint16_t* w, uint8_t k, uint8_t* key){
        uint16_t t;
        t = w[3];
@@ -139,7 +146,7 @@ void skipjack_b(uint16_t* w, uint8_t k, uint8_t* key){
 }
 
 /*****************************************************************************/
-
+static
 void skipjack_b_inv(uint16_t* w, uint8_t k, uint8_t* key){
        uint16_t t;
        t = w[1];