Hardcode numwords in vli_modSub
diff --git a/include/tinycrypt/ecc.h b/include/tinycrypt/ecc.h
index 6895294..3d60267 100644
--- a/include/tinycrypt/ecc.h
+++ b/include/tinycrypt/ecc.h
@@ -343,8 +343,7 @@
* @param num_words IN -- number of words
*/
void uECC_vli_modSub(uECC_word_t *result, const uECC_word_t *left,
- const uECC_word_t *right, const uECC_word_t *mod,
- wordcount_t num_words);
+ const uECC_word_t *right, const uECC_word_t *mod);
/*
* @brief Computes P' = (x1', y1', Z3), P + Q = (x3, y3, Z3) or
diff --git a/tinycrypt/ecc.c b/tinycrypt/ecc.c
index e4e2b45..e7558e9 100644
--- a/tinycrypt/ecc.c
+++ b/tinycrypt/ecc.c
@@ -431,11 +431,9 @@
}
void uECC_vli_modSub(uECC_word_t *result, const uECC_word_t *left,
- const uECC_word_t *right, const uECC_word_t *mod,
- wordcount_t num_words)
+ const uECC_word_t *right, const uECC_word_t *mod)
{
uECC_word_t l_borrow = uECC_vli_sub(result, left, right);
- (void) num_words;
if (l_borrow) {
/* In this case, result == -diff == (max int) - diff. Since -x % d == d - x,
* we can get the correct result from result + mod (with overflow). */
@@ -598,7 +596,7 @@
uECC_vli_modAdd(X1, X1, Z1, curve->p); /* t1 = x1 + z1^2 */
uECC_vli_modAdd(Z1, Z1, Z1, curve->p); /* t3 = 2*z1^2 */
- uECC_vli_modSub(Z1, X1, Z1, curve->p, num_words); /* t3 = x1 - z1^2 */
+ uECC_vli_modSub(Z1, X1, Z1, curve->p); /* t3 = x1 - z1^2 */
uECC_vli_modMult_fast(X1, X1, Z1); /* t1 = x1^2 - z1^4 */
uECC_vli_modAdd(Z1, X1, X1, curve->p); /* t3 = 2*(x1^2 - z1^4) */
@@ -613,12 +611,12 @@
/* t1 = 3/2*(x1^2 - z1^4) = B */
uECC_vli_modMult_fast(Z1, X1, X1); /* t3 = B^2 */
- uECC_vli_modSub(Z1, Z1, t5, curve->p, num_words); /* t3 = B^2 - A */
- uECC_vli_modSub(Z1, Z1, t5, curve->p, num_words); /* t3 = B^2 - 2A = x3 */
- uECC_vli_modSub(t5, t5, Z1, curve->p, num_words); /* t5 = A - x3 */
+ uECC_vli_modSub(Z1, Z1, t5, curve->p); /* t3 = B^2 - A */
+ uECC_vli_modSub(Z1, Z1, t5, curve->p); /* t3 = B^2 - 2A = x3 */
+ uECC_vli_modSub(t5, t5, Z1, curve->p); /* t5 = A - x3 */
uECC_vli_modMult_fast(X1, X1, t5); /* t1 = B * (A - x3) */
/* t4 = B * (A - x3) - y1^4 = y3: */
- uECC_vli_modSub(t4, X1, t4, curve->p, num_words);
+ uECC_vli_modSub(t4, X1, t4, curve->p);
uECC_vli_set(X1, Z1);
uECC_vli_set(Z1, Y1);
@@ -630,10 +628,9 @@
uECC_Curve curve)
{
uECC_word_t _3[NUM_ECC_WORDS] = {3}; /* -a = 3 */
- wordcount_t num_words = curve->num_words;
uECC_vli_modMult_fast(result, x, x); /* r = x^2 */
- uECC_vli_modSub(result, result, _3, curve->p, num_words); /* r = x^2 - 3 */
+ uECC_vli_modSub(result, result, _3, curve->p); /* r = x^2 - 3 */
uECC_vli_modMult_fast(result, result, x); /* r = x^3 - 3x */
/* r = x^3 - 3x + b: */
uECC_vli_modAdd(result, result, curve->b, curve->p);
@@ -790,22 +787,21 @@
/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
uECC_word_t t5[NUM_ECC_WORDS];
const uECC_Curve curve = &curve_secp256r1;
- const wordcount_t num_words = NUM_ECC_WORDS;
- uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */
+ uECC_vli_modSub(t5, X2, X1, curve->p); /* t5 = x2 - x1 */
uECC_vli_modMult_rnd(t5, t5, t5, s); /* t5 = (x2 - x1)^2 = A */
uECC_vli_modMult_rnd(X1, X1, t5, s); /* t1 = x1*A = B */
uECC_vli_modMult_rnd(X2, X2, t5, s); /* t3 = x2*A = C */
- uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */
+ uECC_vli_modSub(Y2, Y2, Y1, curve->p); /* t4 = y2 - y1 */
uECC_vli_modMult_rnd(t5, Y2, Y2, s); /* t5 = (y2 - y1)^2 = D */
- uECC_vli_modSub(t5, t5, X1, curve->p, num_words); /* t5 = D - B */
- uECC_vli_modSub(t5, t5, X2, curve->p, num_words); /* t5 = D - B - C = x3 */
- uECC_vli_modSub(X2, X2, X1, curve->p, num_words); /* t3 = C - B */
+ uECC_vli_modSub(t5, t5, X1, curve->p); /* t5 = D - B */
+ uECC_vli_modSub(t5, t5, X2, curve->p); /* t5 = D - B - C = x3 */
+ uECC_vli_modSub(X2, X2, X1, curve->p); /* t3 = C - B */
uECC_vli_modMult_rnd(Y1, Y1, X2, s); /* t2 = y1*(C - B) */
- uECC_vli_modSub(X2, X1, t5, curve->p, num_words); /* t3 = B - x3 */
+ uECC_vli_modSub(X2, X1, t5, curve->p); /* t3 = B - x3 */
uECC_vli_modMult_rnd(Y2, Y2, X2, s); /* t4 = (y2 - y1)*(B - x3) */
- uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y3 */
+ uECC_vli_modSub(Y2, Y2, Y1, curve->p); /* t4 = y3 */
uECC_vli_set(X2, t5);
}
@@ -831,32 +827,31 @@
uECC_word_t t6[NUM_ECC_WORDS];
uECC_word_t t7[NUM_ECC_WORDS];
const uECC_Curve curve = &curve_secp256r1;
- const wordcount_t num_words = NUM_ECC_WORDS;
- uECC_vli_modSub(t5, X2, X1, curve->p, num_words); /* t5 = x2 - x1 */
+ uECC_vli_modSub(t5, X2, X1, curve->p); /* t5 = x2 - x1 */
uECC_vli_modMult_rnd(t5, t5, t5, s); /* t5 = (x2 - x1)^2 = A */
uECC_vli_modMult_rnd(X1, X1, t5, s); /* t1 = x1*A = B */
uECC_vli_modMult_rnd(X2, X2, t5, s); /* t3 = x2*A = C */
uECC_vli_modAdd(t5, Y2, Y1, curve->p); /* t5 = y2 + y1 */
- uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words); /* t4 = y2 - y1 */
+ uECC_vli_modSub(Y2, Y2, Y1, curve->p); /* t4 = y2 - y1 */
- uECC_vli_modSub(t6, X2, X1, curve->p, num_words); /* t6 = C - B */
+ uECC_vli_modSub(t6, X2, X1, curve->p); /* t6 = C - B */
uECC_vli_modMult_rnd(Y1, Y1, t6, s); /* t2 = y1 * (C - B) = E */
uECC_vli_modAdd(t6, X1, X2, curve->p); /* t6 = B + C */
uECC_vli_modMult_rnd(X2, Y2, Y2, s); /* t3 = (y2 - y1)^2 = D */
- uECC_vli_modSub(X2, X2, t6, curve->p, num_words); /* t3 = D - (B + C) = x3 */
+ uECC_vli_modSub(X2, X2, t6, curve->p); /* t3 = D - (B + C) = x3 */
- uECC_vli_modSub(t7, X1, X2, curve->p, num_words); /* t7 = B - x3 */
+ uECC_vli_modSub(t7, X1, X2, curve->p); /* t7 = B - x3 */
uECC_vli_modMult_rnd(Y2, Y2, t7, s); /* t4 = (y2 - y1)*(B - x3) */
/* t4 = (y2 - y1)*(B - x3) - E = y3: */
- uECC_vli_modSub(Y2, Y2, Y1, curve->p, num_words);
+ uECC_vli_modSub(Y2, Y2, Y1, curve->p);
uECC_vli_modMult_rnd(t7, t5, t5, s); /* t7 = (y2 + y1)^2 = F */
- uECC_vli_modSub(t7, t7, t6, curve->p, num_words); /* t7 = F - (B + C) = x3' */
- uECC_vli_modSub(t6, t7, X1, curve->p, num_words); /* t6 = x3' - B */
+ uECC_vli_modSub(t7, t7, t6, curve->p); /* t7 = F - (B + C) = x3' */
+ uECC_vli_modSub(t6, t7, X1, curve->p); /* t6 = x3' - B */
uECC_vli_modMult_rnd(t6, t6, t5, s); /* t6 = (y2+y1)*(x3' - B) */
/* t2 = (y2+y1)*(x3' - B) - E = y3': */
- uECC_vli_modSub(Y1, t6, Y1, curve->p, num_words);
+ uECC_vli_modSub(Y1, t6, Y1, curve->p);
uECC_vli_set(X1, t7);
}
@@ -894,7 +889,7 @@
XYcZ_addC_rnd(Rx[1 - nb], Ry[1 - nb], Rx[nb], Ry[nb], ws);
/* Find final 1/Z value. */
- uECC_vli_modSub(z, Rx[1], Rx[0], curve->p, num_words); /* X1 - X0 */
+ uECC_vli_modSub(z, Rx[1], Rx[0], curve->p); /* X1 - X0 */
uECC_vli_modMult_fast(z, z, Ry[1 - nb]); /* Yb * (X1 - X0) */
uECC_vli_modMult_fast(z, z, point); /* xP * Yb * (X1 - X0) */
uECC_vli_modInv(z, z, curve->p, num_words); /* 1 / (xP * Yb * (X1 - X0))*/
diff --git a/tinycrypt/ecc_dsa.c b/tinycrypt/ecc_dsa.c
index e6ce7fc..77e3efe 100644
--- a/tinycrypt/ecc_dsa.c
+++ b/tinycrypt/ecc_dsa.c
@@ -253,7 +253,7 @@
uECC_vli_set(sum + num_words, _public + num_words);
uECC_vli_set(tx, curve->G);
uECC_vli_set(ty, curve->G + num_words);
- uECC_vli_modSub(z, sum, tx, curve->p, num_words); /* z = x2 - x1 */
+ uECC_vli_modSub(z, sum, tx, curve->p); /* z = x2 - x1 */
XYcZ_add(tx, ty, sum, sum + num_words, curve);
uECC_vli_modInv(z, z, curve->p, num_words); /* z = 1/z */
apply_z(sum, sum + num_words, z);
@@ -283,7 +283,7 @@
uECC_vli_set(tx, point);
uECC_vli_set(ty, point + num_words);
apply_z(tx, ty, z);
- uECC_vli_modSub(tz, rx, tx, curve->p, num_words); /* Z = x2 - x1 */
+ uECC_vli_modSub(tz, rx, tx, curve->p); /* Z = x2 - x1 */
XYcZ_add(tx, ty, rx, ry, curve);
uECC_vli_modMult_fast(z, z, tz);
}