Remove unnecessary NULL checks, part 2.

Stuff in crypto/ec.

Change-Id: I3bd238c365c4766ed8abc6f835a107478b43b159
Reviewed-on: https://boringssl-review.googlesource.com/4515
Reviewed-by: Adam Langley <agl@google.com>

8 files changed, 88 insertions, 238 deletions

diff --git a/crypto/ec/ec.c b/crypto/ec/ec.c
index ab65ffb0..10220cbc 100644
--- a/crypto/ec/ec.c
+++ b/crypto/ec/ec.c
@@ -364,30 +364,14 @@ err:
     EC_GROUP_free(group);
     group = NULL;
   }
-  if (P) {
-    EC_POINT_free(P);
-  }
-  if (ctx) {
-    BN_CTX_free(ctx);
-  }
-  if (p) {
-    BN_free(p);
-  }
-  if (a) {
-    BN_free(a);
-  }
-  if (b) {
-    BN_free(b);
-  }
-  if (order) {
-    BN_free(order);
-  }
-  if (x) {
-    BN_free(x);
-  }
-  if (y) {
-    BN_free(y);
-  }
+  EC_POINT_free(P);
+  BN_CTX_free(ctx);
+  BN_free(p);
+  BN_free(a);
+  BN_free(b);
+  BN_free(order);
+  BN_free(x);
+  BN_free(y);
   return group;
 }
 
@@ -424,9 +408,7 @@ void EC_GROUP_free(EC_GROUP *group) {
 
   ec_pre_comp_free(group->pre_comp);
 
-  if (group->generator != NULL) {
-    EC_POINT_free(group->generator);
-  }
+  EC_POINT_free(group->generator);
   BN_free(&group->order);
   BN_free(&group->cofactor);
 
@@ -497,9 +479,7 @@ EC_GROUP *EC_GROUP_dup(const EC_GROUP *a) {
 
 err:
   if (!ok) {
-    if (t) {
-      EC_GROUP_free(t);
-    }
+    EC_GROUP_free(t);
     return NULL;
   } else {
     return t;
diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c
index c32ae131..ff3dca6d 100644
--- a/crypto/ec/ec_asn1.c
+++ b/crypto/ec/ec_asn1.c
@@ -172,9 +172,7 @@ ECPKPARAMETERS *ec_asn1_group2pkparameters(const EC_GROUP *group,
       return NULL;
     }
   } else {
-    if (ret->value.named_curve) {
-      ASN1_OBJECT_free(ret->value.named_curve);
-    }
+    ASN1_OBJECT_free(ret->value.named_curve);
   }
 
   /* use the ASN.1 OID to describe the the elliptic curve parameters. */
@@ -257,10 +255,8 @@ static EC_GROUP *d2i_ECPKParameters(EC_GROUP **groupp, const uint8_t **inp,
     return NULL;
   }
 
-  if (groupp && *groupp) {
-    EC_GROUP_free(*groupp);
-  }
   if (groupp) {
+    EC_GROUP_free(*groupp);
     *groupp = group;
   }
 
@@ -307,9 +303,7 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **in, long len) {
   }
 
   if (priv_key->parameters) {
-    if (ret->group) {
-      EC_GROUP_free(ret->group);
-    }
+    EC_GROUP_free(ret->group);
     ret->group = ec_asn1_pkparameters2group(priv_key->parameters);
   }
 
@@ -333,9 +327,7 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **in, long len) {
     goto err;
   }
 
-  if (ret->pub_key) {
-    EC_POINT_free(ret->pub_key);
-  }
+  EC_POINT_free(ret->pub_key);
   ret->pub_key = EC_POINT_new(ret->group);
   if (ret->pub_key == NULL) {
     OPENSSL_PUT_ERROR(EC, d2i_ECPrivateKey, ERR_R_EC_LIB);
@@ -377,15 +369,13 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const uint8_t **in, long len) {
 
 err:
   if (!ok) {
-    if (ret && (a == NULL || *a != ret)) {
+    if (a == NULL || *a != ret) {
       EC_KEY_free(ret);
     }
     ret = NULL;
   }
 
-  if (priv_key) {
-    EC_PRIVATEKEY_free(priv_key);
-  }
+  EC_PRIVATEKEY_free(priv_key);
 
   return ret;
 }
@@ -478,12 +468,8 @@ int i2d_ECPrivateKey(const EC_KEY *key, uint8_t **outp) {
   ok = 1;
 
 err:
-  if (buffer) {
-    OPENSSL_free(buffer);
-  }
-  if (priv_key) {
-    EC_PRIVATEKEY_free(priv_key);
-  }
+  OPENSSL_free(buffer);
+  EC_PRIVATEKEY_free(priv_key);
   return (ok ? ret : 0);
 }
 
diff --git a/crypto/ec/ec_key.c b/crypto/ec/ec_key.c
index 0f4e666b..bbf5fee8 100644
--- a/crypto/ec/ec_key.c
+++ b/crypto/ec/ec_key.c
@@ -153,15 +153,9 @@ void EC_KEY_free(EC_KEY *r) {
     METHOD_unref(r->ecdsa_meth);
   }
 
-  if (r->group != NULL) {
-    EC_GROUP_free(r->group);
-  }
-  if (r->pub_key != NULL) {
-    EC_POINT_free(r->pub_key);
-  }
-  if (r->priv_key != NULL) {
-    BN_clear_free(r->priv_key);
-  }
+  EC_GROUP_free(r->group);
+  EC_POINT_free(r->pub_key);
+  BN_clear_free(r->priv_key);
 
   CRYPTO_free_ex_data(&g_ex_data_class, r, &r->ex_data);
 
@@ -177,9 +171,7 @@ EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src) {
   /* Copy the parameters. */
   if (src->group) {
     /* TODO(fork): duplicating the group seems wasteful. */
-    if (dest->group) {
-      EC_GROUP_free(dest->group);
-    }
+    EC_GROUP_free(dest->group);
     dest->group = EC_GROUP_dup(src->group);
     if (dest->group == NULL) {
       return NULL;
@@ -188,9 +180,7 @@ EC_KEY *EC_KEY_copy(EC_KEY *dest, const EC_KEY *src) {
 
   /* Copy the public key. */
   if (src->pub_key && src->group) {
-    if (dest->pub_key) {
-      EC_POINT_free(dest->pub_key);
-    }
+    EC_POINT_free(dest->pub_key);
     dest->pub_key = EC_POINT_dup(src->pub_key, src->group);
     if (dest->pub_key == NULL) {
       return NULL;
@@ -248,9 +238,7 @@ int EC_KEY_is_opaque(const EC_KEY *key) {
 const EC_GROUP *EC_KEY_get0_group(const EC_KEY *key) { return key->group; }
 
 int EC_KEY_set_group(EC_KEY *key, const EC_GROUP *group) {
-  if (key->group != NULL) {
-    EC_GROUP_free(key->group);
-  }
+  EC_GROUP_free(key->group);
   /* TODO(fork): duplicating the group seems wasteful but see
    * |EC_KEY_set_conv_form|. */
   key->group = EC_GROUP_dup(group);
@@ -262,9 +250,7 @@ const BIGNUM *EC_KEY_get0_private_key(const EC_KEY *key) {
 }
 
 int EC_KEY_set_private_key(EC_KEY *key, const BIGNUM *priv_key) {
-  if (key->priv_key) {
-    BN_clear_free(key->priv_key);
-  }
+  BN_clear_free(key->priv_key);
   key->priv_key = BN_dup(priv_key);
   return (key->priv_key == NULL) ? 0 : 1;
 }
@@ -274,9 +260,7 @@ const EC_POINT *EC_KEY_get0_public_key(const EC_KEY *key) {
 }
 
 int EC_KEY_set_public_key(EC_KEY *key, const EC_POINT *pub_key) {
-  if (key->pub_key != NULL) {
-    EC_POINT_free(key->pub_key);
-  }
+  EC_POINT_free(key->pub_key);
   key->pub_key = EC_POINT_dup(pub_key, key->group);
   return (key->pub_key == NULL) ? 0 : 1;
 }
@@ -367,12 +351,8 @@ int EC_KEY_check_key(const EC_KEY *eckey) {
   ok = 1;
 
 err:
-  if (ctx != NULL) {
-    BN_CTX_free(ctx);
-  }
-  if (point != NULL) {
-    EC_POINT_free(point);
-  }
+  BN_CTX_free(ctx);
+  EC_POINT_free(point);
   return ok;
 }
 
@@ -423,12 +403,8 @@ int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
   ok = 1;
 
 err:
-  if (ctx) {
-    BN_CTX_free(ctx);
-  }
-  if (point) {
-    EC_POINT_free(point);
-  }
+  BN_CTX_free(ctx);
+  EC_POINT_free(point);
   return ok;
 }
 
@@ -489,18 +465,14 @@ int EC_KEY_generate_key(EC_KEY *eckey) {
   ok = 1;
 
 err:
-  if (order) {
-    BN_free(order);
-  }
-  if (pub_key != NULL && eckey->pub_key == NULL) {
+  BN_free(order);
+  if (eckey->pub_key == NULL) {
     EC_POINT_free(pub_key);
   }
-  if (priv_key != NULL && eckey->priv_key == NULL) {
+  if (eckey->priv_key == NULL) {
     BN_free(priv_key);
   }
-  if (ctx != NULL) {
-    BN_CTX_free(ctx);
-  }
+  BN_CTX_free(ctx);
   return ok;
 }
 
diff --git a/crypto/ec/ec_montgomery.c b/crypto/ec/ec_montgomery.c
index f152b13f..74dbc6ce 100644
--- a/crypto/ec/ec_montgomery.c
+++ b/crypto/ec/ec_montgomery.c
@@ -127,38 +127,26 @@ int ec_GFp_mont_group_init(EC_GROUP *group) {
 }
 
 void ec_GFp_mont_group_finish(EC_GROUP *group) {
-  if (group->mont != NULL) {
-    BN_MONT_CTX_free(group->mont);
-    group->mont = NULL;
-  }
-  if (group->one != NULL) {
-    BN_free(group->one);
-    group->one = NULL;
-  }
+  BN_MONT_CTX_free(group->mont);
+  group->mont = NULL;
+  BN_free(group->one);
+  group->one = NULL;
   ec_GFp_simple_group_finish(group);
 }
 
 void ec_GFp_mont_group_clear_finish(EC_GROUP *group) {
-  if (group->mont != NULL) {
-    BN_MONT_CTX_free(group->mont);
-    group->mont = NULL;
-  }
-  if (group->one != NULL) {
-    BN_clear_free(group->one);
-    group->one = NULL;
-  }
+  BN_MONT_CTX_free(group->mont);
+  group->mont = NULL;
+  BN_clear_free(group->one);
+  group->one = NULL;
   ec_GFp_simple_group_clear_finish(group);
 }
 
 int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src) {
-  if (dest->mont != NULL) {
-    BN_MONT_CTX_free(dest->mont);
-    dest->mont = NULL;
-  }
-  if (dest->one != NULL) {
-    BN_clear_free(dest->one);
-    dest->one = NULL;
-  }
+  BN_MONT_CTX_free(dest->mont);
+  dest->mont = NULL;
+  BN_clear_free(dest->one);
+  dest->one = NULL;
 
   if (!ec_GFp_simple_group_copy(dest, src)) {
     return 0;
@@ -183,10 +171,8 @@ int ec_GFp_mont_group_copy(EC_GROUP *dest, const EC_GROUP *src) {
   return 1;
 
 err:
-  if (dest->mont != NULL) {
-    BN_MONT_CTX_free(dest->mont);
-    dest->mont = NULL;
-  }
+  BN_MONT_CTX_free(dest->mont);
+  dest->mont = NULL;
   return 0;
 }
 
@@ -197,14 +183,10 @@ int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
   BIGNUM *one = NULL;
   int ret = 0;
 
-  if (group->mont != NULL) {
-    BN_MONT_CTX_free(group->mont);
-    group->mont = NULL;
-  }
-  if (group->one != NULL) {
-    BN_free(group->one);
-    group->one = NULL;
-  }
+  BN_MONT_CTX_free(group->mont);
+  group->mont = NULL;
+  BN_free(group->one);
+  group->one = NULL;
 
   if (ctx == NULL) {
     ctx = new_ctx = BN_CTX_new();
@@ -241,15 +223,9 @@ int ec_GFp_mont_group_set_curve(EC_GROUP *group, const BIGNUM *p,
   }
 
 err:
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
-  if (mont != NULL) {
-    BN_MONT_CTX_free(mont);
-  }
-  if (one != NULL) {
-    BN_free(one);
-  }
+  BN_CTX_free(new_ctx);
+  BN_MONT_CTX_free(mont);
+  BN_free(one);
   return ret;
 }
 
diff --git a/crypto/ec/oct.c b/crypto/ec/oct.c
index 1cb7c2f0..816a42f5 100644
--- a/crypto/ec/oct.c
+++ b/crypto/ec/oct.c
@@ -164,18 +164,14 @@ static size_t ec_GFp_simple_point2oct(const EC_GROUP *group,
   if (used_ctx) {
     BN_CTX_end(ctx);
   }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 
 err:
   if (used_ctx) {
     BN_CTX_end(ctx);
   }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return 0;
 }
 
@@ -275,9 +271,7 @@ static int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -456,9 +450,7 @@ int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
diff --git a/crypto/ec/p256-64.c b/crypto/ec/p256-64.c
index a1d278e1..8f824dec 100644
--- a/crypto/ec/p256-64.c
+++ b/crypto/ec/p256-64.c
@@ -1647,9 +1647,7 @@ int ec_GFp_nistp256_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -1899,21 +1897,11 @@ int ec_GFp_nistp256_points_mul(const EC_GROUP *group, EC_POINT *r,
 
 err:
   BN_CTX_end(ctx);
-  if (generator != NULL) {
-    EC_POINT_free(generator);
-  }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
-  if (secrets != NULL) {
-    OPENSSL_free(secrets);
-  }
-  if (pre_comp != NULL) {
-    OPENSSL_free(pre_comp);
-  }
-  if (tmp_smallfelems != NULL) {
-    OPENSSL_free(tmp_smallfelems);
-  }
+  EC_POINT_free(generator);
+  BN_CTX_free(new_ctx);
+  OPENSSL_free(secrets);
+  OPENSSL_free(pre_comp);
+  OPENSSL_free(tmp_smallfelems);
   return ret;
 }
 
diff --git a/crypto/ec/simple.c b/crypto/ec/simple.c
index 24781195..69fd2e43 100644
--- a/crypto/ec/simple.c
+++ b/crypto/ec/simple.c
@@ -226,9 +226,7 @@ int ec_GFp_simple_group_set_curve(EC_GROUP *group, const BIGNUM *p,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -268,9 +266,7 @@ int ec_GFp_simple_group_get_curve(const EC_GROUP *group, BIGNUM *p, BIGNUM *a,
   ret = 1;
 
 err:
-  if (new_ctx) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -345,9 +341,7 @@ err:
   if (ctx != NULL) {
     BN_CTX_end(ctx);
   }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -446,9 +440,7 @@ int ec_GFp_simple_set_Jprojective_coordinates_GFp(
   ret = 1;
 
 err:
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -491,9 +483,7 @@ int ec_GFp_simple_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
   ret = 1;
 
 err:
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -612,9 +602,7 @@ int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -805,9 +793,7 @@ end:
     /* otherwise we already called BN_CTX_end */
     BN_CTX_end(ctx);
   }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -934,9 +920,7 @@ int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -1053,9 +1037,7 @@ int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -1168,9 +1150,7 @@ int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
 
 end:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -1211,9 +1191,7 @@ int ec_GFp_simple_make_affine(const EC_GROUP *group, EC_POINT *point,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   return ret;
 }
 
@@ -1358,9 +1336,7 @@ int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
 
 err:
   BN_CTX_end(ctx);
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
+  BN_CTX_free(new_ctx);
   if (prod_Z != NULL) {
     for (i = 0; i < num; i++) {
       if (prod_Z[i] == NULL) {
diff --git a/crypto/ec/wnaf.c b/crypto/ec/wnaf.c
index 0beee2f9..d87a7d97 100644
--- a/crypto/ec/wnaf.c
+++ b/crypto/ec/wnaf.c
@@ -631,18 +631,10 @@ int ec_wNAF_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
   ret = 1;
 
 err:
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
-  if (tmp != NULL) {
-    EC_POINT_free(tmp);
-  }
-  if (wsize != NULL) {
-    OPENSSL_free(wsize);
-  }
-  if (wNAF_len != NULL) {
-    OPENSSL_free(wNAF_len);
-  }
+  BN_CTX_free(new_ctx);
+  EC_POINT_free(tmp);
+  OPENSSL_free(wsize);
+  OPENSSL_free(wNAF_len);
   if (wNAF != NULL) {
     signed char **w;
 
@@ -659,9 +651,7 @@ err:
 
     OPENSSL_free(val);
   }
-  if (val_sub != NULL) {
-    OPENSSL_free(val_sub);
-  }
+  OPENSSL_free(val_sub);
   return ret;
 }
 
@@ -699,10 +689,8 @@ int ec_wNAF_precompute_mult(EC_GROUP *group, BN_CTX *ctx) {
   int ret = 0;
 
   /* if there is an old EC_PRE_COMP object, throw it away */
-  if (group->pre_comp) {
-    ec_pre_comp_free(group->pre_comp);
-    group->pre_comp = NULL;
-  }
+  ec_pre_comp_free(group->pre_comp);
+  group->pre_comp = NULL;
 
   generator = EC_GROUP_get0_generator(group);
   if (generator == NULL) {
@@ -841,12 +829,8 @@ err:
   if (ctx != NULL) {
     BN_CTX_end(ctx);
   }
-  if (new_ctx != NULL) {
-    BN_CTX_free(new_ctx);
-  }
-  if (pre_comp) {
-    ec_pre_comp_free(pre_comp);
-  }
+  BN_CTX_free(new_ctx);
+  ec_pre_comp_free(pre_comp);
   if (points) {
     EC_POINT **p;
 
@@ -855,12 +839,8 @@ err:
     }
     OPENSSL_free(points);
   }
-  if (tmp_point) {
-    EC_POINT_free(tmp_point);
-  }
-  if (base) {
-    EC_POINT_free(base);
-  }
+  EC_POINT_free(tmp_point);
+  EC_POINT_free(base);
   return ret;
 }