commit b121a2673645c08d1384ba6497f4397d3fdb1a11
author Brian Smith <brian@briansmith.org> Fri Feb 05 14:18:26 2016 -1000
committer David Benjamin <davidben@google.com> Mon Feb 08 18:33:09 2016 +0000
tree eacfb38d26116d9a04a23a48fbe45f0aa64aab93
parent 4862b3b93ccae376a357de002120df089d3e4c53

Remove unused |ec_GFp_simple_group_check_discriminant|.

Change-Id: I995a445fea1de7f85ec917694abb8273a82339d3
Reviewed-on: https://boringssl-review.googlesource.com/7092
Reviewed-by: David Benjamin <davidben@google.com>

crypto/ec/internal.h

diff --git a/crypto/ec/internal.h b/crypto/ec/internal.h
index d1881b8..55d2afa 100644
--- a/crypto/ec/internal.h
+++ b/crypto/ec/internal.h
@@ -174,7 +174,6 @@
 int ec_GFp_simple_group_get_curve(const EC_GROUP *, BIGNUM *p, BIGNUM *a,
                                   BIGNUM *b, BN_CTX *);
 unsigned ec_GFp_simple_group_get_degree(const EC_GROUP *);
-int ec_GFp_simple_group_check_discriminant(const EC_GROUP *, BN_CTX *);
 int ec_GFp_simple_point_init(EC_POINT *);
 void ec_GFp_simple_point_finish(EC_POINT *);
 void ec_GFp_simple_point_clear_finish(EC_POINT *);

crypto/ec/simple.c

diff --git a/crypto/ec/simple.c b/crypto/ec/simple.c
index 354b1c7..4eb612e 100644
--- a/crypto/ec/simple.c
+++ b/crypto/ec/simple.c
@@ -224,76 +224,6 @@
   return BN_num_bits(&group->field);
 }
 
-int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx) {
-  int ret = 0;
-  BIGNUM *a, *b, *order, *tmp_1, *tmp_2;
-  const BIGNUM *p = &group->field;
-  BN_CTX *new_ctx = NULL;
-
-  if (ctx == NULL) {
-    ctx = new_ctx = BN_CTX_new();
-    if (ctx == NULL) {
-      OPENSSL_PUT_ERROR(EC, ERR_R_MALLOC_FAILURE);
-      goto err;
-    }
-  }
-  BN_CTX_start(ctx);
-  a = BN_CTX_get(ctx);
-  b = BN_CTX_get(ctx);
-  tmp_1 = BN_CTX_get(ctx);
-  tmp_2 = BN_CTX_get(ctx);
-  order = BN_CTX_get(ctx);
-  if (order == NULL) {
-    goto err;
-  }
-
-  if (group->meth->field_decode) {
-    if (!group->meth->field_decode(group, a, &group->a, ctx) ||
-        !group->meth->field_decode(group, b, &group->b, ctx)) {
-      goto err;
-    }
-  } else {
-    if (!BN_copy(a, &group->a) || !BN_copy(b, &group->b)) {
-      goto err;
-    }
-  }
-
-  /* check the discriminant:
-   * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p)
-   * 0 =< a, b < p */
-  if (BN_is_zero(a)) {
-    if (BN_is_zero(b)) {
-      goto err;
-    }
-  } else if (!BN_is_zero(b)) {
-    if (!BN_mod_sqr(tmp_1, a, p, ctx) ||
-        !BN_mod_mul(tmp_2, tmp_1, a, p, ctx) ||
-        !BN_lshift(tmp_1, tmp_2, 2)) {
-      goto err;
-    }
-    /* tmp_1 = 4*a^3 */
-
-    if (!BN_mod_sqr(tmp_2, b, p, ctx) ||
-        !BN_mul_word(tmp_2, 27)) {
-      goto err;
-    }
-    /* tmp_2 = 27*b^2 */
-
-    if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx) ||
-        BN_is_zero(a)) {
-      goto err;
-    }
-  }
-  ret = 1;
-
-err:
-  if (ctx != NULL) {
-    BN_CTX_end(ctx);
-  }
-  BN_CTX_free(new_ctx);
-  return ret;
-}
-
 int ec_GFp_simple_point_init(EC_POINT *point) {
   BN_init(&point->X);
   BN_init(&point->Y);