From c1a5fb54dd57088c1b0acd99c4cc8c2b7cafe51a Mon Sep 17 00:00:00 2001
From: "Diego F. Aranha" <dfaranha@gmail.com>
Date: Sat, 28 Dec 2024 20:31:08 +0100
Subject: [PATCH] Fix regressions from last commit.

---
 src/bn/relic_bn_rec.c   | 50 ++++++++++++++++++-----------------------
 src/ep/relic_ep_curve.c |  8 +++----
 test/test_bn.c          | 12 ++++------
 test/test_ep.c          |  4 ++--
 4 files changed, 32 insertions(+), 42 deletions(-)

diff --git a/src/bn/relic_bn_rec.c b/src/bn/relic_bn_rec.c
index 69c46196f..0e05cae33 100644
--- a/src/bn/relic_bn_rec.c
+++ b/src/bn/relic_bn_rec.c
@@ -829,11 +829,11 @@ void bn_rec_jsf(int8_t *jsf, size_t *len, const bn_t k, const bn_t l) {
 
 }
 
-void bn_rec_glv(bn_t k0, bn_t k1, const bn_t k, const bn_t n, const bn_t *v1,
-		const bn_t *v2) {
+void bn_rec_glv(bn_t k0, bn_t k1, const bn_t k, const bn_t n, const bn_st *v1,
+		const bn_st *v2) {
 	bn_t t, b1, b2;
 	int r1, r2;
-	size_t bits = bn_bits(n), d = bits >> (RLC_DIG_LOG), b = bits % RLC_DIG;
+	size_t bits;
 
 	bn_null(b1);
 	bn_null(b2);
@@ -844,35 +844,26 @@ void bn_rec_glv(bn_t k0, bn_t k1, const bn_t k, const bn_t n, const bn_t *v1,
 		bn_new(b2);
 		bn_new(t);
 
-		dv_zero(t->dp, RLC_BN_SIZE);
-		dv_copy(t->dp, k->dp, k->used);
-		
-		dv_zero(b1->dp, RLC_BN_SIZE);
-		dv_copy(b1->dp, v1[0]->dp, v1[0]->used);
-		b1->sign = v1[0]->sign;
-		b1->used = v1[0]->used;
-		
-		dv_zero(b2->dp, RLC_BN_SIZE);
-		t->used = k->used;
-		bn_mul(b1, b1, t);
-		r1 = (b1->dp[d] >> b) & (dig_t)1;
-		dv_rshd(b1->dp, b1->dp, RLC_BN_SIZE, d);
-		bn_rshb_low(b1->dp, b1->dp, RLC_BN_SIZE, b + 1);
+		bn_abs(t, k);
+		bits = bn_bits(n);
+
+		bn_mul(b1, t, &(v1[0]));
+		r1 = bn_get_bit(b1, bits);
+		bn_rsh(b1, b1, bits + 1);
 		bn_add_dig(b1, b1, r1);
 
-		bn_mul(b2, t, v2[0]);
-		r2 = (b2->dp[d] >> b) & (dig_t)1;
-		dv_rshd(b2->dp, b2->dp, RLC_BN_SIZE, d);
-		bn_rshb_low(b2->dp, b2->dp, RLC_BN_SIZE, b + 1);
+		bn_mul(b2, t, &(v2[0]));
+		r2 = bn_get_bit(b2, bits);
+		bn_rsh(b2, b2, bits + 1);
 		bn_add_dig(b2, b2, r2);
 
-		bn_mul(k0, b1, v1[1]);
-		bn_mul(k1, b2, v2[1]);
+		bn_mul(k0, b1, &(v1[1]));
+		bn_mul(k1, b2, &(v2[1]));
 		bn_add(k0, k0, k1);
 		bn_sub(k0, t, k0);
 
-		bn_mul(k1, b1, v1[2]);
-		bn_mul(t, b2, v2[2]);
+		bn_mul(k1, b1, &(v1[2]));
+		bn_mul(t, b2, &(v2[2]));
 		bn_add(k1, k1, t);
 		bn_neg(k1, k1);
 	}
@@ -886,7 +877,7 @@ void bn_rec_glv(bn_t k0, bn_t k1, const bn_t k, const bn_t n, const bn_t *v1,
 	}
 }
 
-void bn_rec_sac(int8_t *b, size_t *len, bn_t *k, size_t c, size_t m, size_t n) {
+void bn_rec_sac(int8_t *b, size_t *len, const bn_t *k, size_t c, size_t m, size_t n) {
 	/* Assume k0 is the sign-aligner. */
 	bn_t *t = RLC_ALLOCA(bn_t, m);
 	size_t l = RLC_CEIL(n, c * m) + 1;
@@ -905,11 +896,14 @@ void bn_rec_sac(int8_t *b, size_t *len, bn_t *k, size_t c, size_t m, size_t n) {
 	}
 
 	RLC_TRY {
-		fp_prime_get_par(t[0]);
-		l = RLC_MAX(l, bn_bits(t[0]) + 1);
 		for (size_t i = 0; i < m; i++) {
 			bn_null(t[i]);
 			bn_new(t[i]);
+		}
+
+		fp_prime_get_par(t[0]);
+		l = RLC_MAX(l, bn_bits(t[0]) + 1);
+		for (size_t i = 0; i < m; i++) {
 			bn_copy(t[i], k[i]);
 			/* The current basis for some curves might be one bit longer. */
 			if (ep_curve_is_pairf() == EP_BN) {
diff --git a/src/ep/relic_ep_curve.c b/src/ep/relic_ep_curve.c
index ebb78d054..9659ebf96 100644
--- a/src/ep/relic_ep_curve.c
+++ b/src/ep/relic_ep_curve.c
@@ -272,12 +272,12 @@ dig_t *ep_curve_get_beta(void) {
 	return core_get()->beta;
 }
 
-const bn_t *ep_curve_get_v1(void) {
-	return (const bn_t *)core_get()->ep_v1;
+const bn_st *ep_curve_get_v1(void) {
+	return (const bn_st *)core_get()->ep_v1;
 }
 
-const bn_t *ep_curve_get_v2(void) {
-	return (const bn_t *)core_get()->ep_v2;
+const bn_st *ep_curve_get_v2(void) {
+	return (const bn_st *)core_get()->ep_v2;
 }
 
 #endif
diff --git a/test/test_bn.c b/test/test_bn.c
index 8c4e4c7fc..8e435c413 100644
--- a/test/test_bn.c
+++ b/test/test_bn.c
@@ -2244,12 +2244,12 @@ static int recoding(void) {
 		TEST_CASE("glv recoding is correct") {
 			if (ep_param_set_any_endom() == RLC_OK) {
 				for (size_t i = 0; i < 3; i++) {
-					bn_copy(v1[i], ep_curve_get_v1()[i]);
-					bn_copy(v2[i], ep_curve_get_v2()[i]);
+					bn_copy(v1[i], &(core_get()->ep_v1[i]));
+					bn_copy(v2[i], &(core_get()->ep_v2[i]));
 				}
 				ep_curve_get_ord(b);
 				bn_rand_mod(a, b);
-				bn_rec_glv(b, c, a, b, (const bn_t *)v1, (const bn_t *)v2);
+				bn_rec_glv(b, c, a, b, ep_curve_get_v1(), ep_curve_get_v2());
 				ep_curve_get_ord(v2[0]);
 				/* Check that subscalars have the right length. */
 				TEST_ASSERT(bn_bits(b) <= 1 + (bn_bits(v2[0]) >> 1), end);
@@ -2288,13 +2288,9 @@ static int recoding(void) {
 			size_t l = RLC_BN_BITS;
 			int8_t ptr[2 * RLC_BN_BITS] = { 0 };
 			if (ep_param_set_any_endom() == RLC_OK) {
-				for (size_t i = 0; i < 3; i++) {
-					bn_copy(v1[i], ep_curve_get_v1()[i]);
-					bn_copy(v2[i], ep_curve_get_v2()[i]);
-				}
 				ep_curve_get_ord(b);
 				bn_rand_mod(a, b);
-				bn_rec_glv(b, c, a, b, (const bn_t *)v1, (const bn_t *)v2);
+				bn_rec_glv(b, c, a, b, ep_curve_get_v1(), ep_curve_get_v2());
 				ep_curve_get_ord(v2[0]);
 				bn_rec_sac(ptr, &l, v1, 1, 2, bn_bits(v2[0]));
 				if (bn_is_even(b)) {
diff --git a/test/test_ep.c b/test/test_ep.c
index 391943a84..c7a7c1bdb 100644
--- a/test/test_ep.c
+++ b/test/test_ep.c
@@ -500,8 +500,8 @@ static int endomorphism(void) {
 		if (ep_curve_is_endom()) {
 			/* Recover lambda parameter. */
 			for (size_t i = 0; i < 3; i++) {
-				bn_copy(v1[i], ep_curve_get_v1()[i]);
-				bn_copy(v2[i], ep_curve_get_v2()[i]);
+				bn_copy(v1[i], &(core_get()->ep_v1[i]));
+				bn_copy(v2[i], &(core_get()->ep_v2[i]));
 			}
 			ep_curve_get_ord(v2[0]);
 			if (bn_cmp_dig(v1[2], 1) == RLC_EQ) {