Remove unnecessary NULL checks, part 1.

First batch of the alphabet.

Change-Id: If4e60f4fbb69e04eb4b70aa1b2240e329251bfa5
Reviewed-on: https://boringssl-review.googlesource.com/4514
Reviewed-by: Adam Langley <agl@google.com>

crypto/bio/buffer.c

@@ -122,17 +122,13 @@ err1:
 static int buffer_free(BIO *bio) {
   BIO_F_BUFFER_CTX *ctx;
 
-  if (bio == NULL) {
+  if (bio == NULL || bio->ptr == NULL) {
     return 0;
   }
 
   ctx = (BIO_F_BUFFER_CTX *)bio->ptr;
-  if (ctx->ibuf != NULL) {
-    OPENSSL_free(ctx->ibuf);
-  }
-  if (ctx->obuf != NULL) {
-    OPENSSL_free(ctx->obuf);
-  }
+  OPENSSL_free(ctx->ibuf);
+  OPENSSL_free(ctx->obuf);
   OPENSSL_free(bio->ptr);
 
   bio->ptr = NULL;

crypto/bio/connect.c

@@ -161,9 +161,7 @@ static int conn_state(BIO *bio, BIO_CONNECT *c) {
                 break;
               }
             }
-            if (c->param_port != NULL) {
-              OPENSSL_free(c->param_port);
-            }
+            OPENSSL_free(c->param_port);
             c->param_port = BUF_strdup(p);
           }
         }
@@ -286,12 +284,8 @@ static void BIO_CONNECT_free(BIO_CONNECT *c) {
     return;
   }
 
-  if (c->param_hostname != NULL) {
-    OPENSSL_free(c->param_hostname);
-  }
-  if (c->param_port != NULL) {
-    OPENSSL_free(c->param_port);
-  }
+  OPENSSL_free(c->param_hostname);
+  OPENSSL_free(c->param_port);
   OPENSSL_free(c);
 }
 
@@ -426,17 +420,13 @@ static long conn_ctrl(BIO *bio, int cmd, long num, void *ptr) {
       if (ptr != NULL) {
         bio->init = 1;
         if (num == 0) {
-          if (data->param_hostname != NULL) {
-            OPENSSL_free(data->param_hostname);
-          }
+          OPENSSL_free(data->param_hostname);
           data->param_hostname = BUF_strdup(ptr);
           if (data->param_hostname == NULL) {
             ret = 0;
           }
         } else if (num == 1) {
-          if (data->param_port != NULL) {
-            OPENSSL_free(data->param_port);
-          }
+          OPENSSL_free(data->param_port);
           data->param_port = BUF_strdup(ptr);
           if (data->param_port == NULL) {
             ret = 0;

crypto/bio/pair.c

@@ -145,7 +145,7 @@ static int bio_free(BIO *bio) {
     bio_destroy_pair(bio);
   }
 
-  if (b->buf != NULL && !b->buf_externally_allocated) {
+  if (!b->buf_externally_allocated) {
     OPENSSL_free(b->buf);
   }
 
@@ -793,14 +793,10 @@ int BIO_new_bio_pair_external_buf(BIO** bio1_p, size_t writebuf1_len,
 
 err:
   if (ret == 0) {
-    if (bio1) {
-      BIO_free(bio1);
-      bio1 = NULL;
-    }
-    if (bio2) {
-      BIO_free(bio2);
-      bio2 = NULL;
-    }
+    BIO_free(bio1);
+    bio1 = NULL;
+    BIO_free(bio2);
+    bio2 = NULL;
   }
 
   *bio1_p = bio1;

crypto/bn/bn.c

@@ -88,7 +88,7 @@ void BN_free(BIGNUM *bn) {
     return;
   }
 
-  if (bn->d != NULL && (bn->flags & BN_FLG_STATIC_DATA) == 0) {
+  if ((bn->flags & BN_FLG_STATIC_DATA) == 0) {
     OPENSSL_free(bn->d);
   }
 
@@ -304,9 +304,7 @@ BIGNUM *bn_wexpand(BIGNUM *bn, unsigned words) {
 
   memcpy(a, bn->d, sizeof(BN_ULONG) * bn->top);
 
-  if (bn->d) {
-    OPENSSL_free(bn->d);
-  }
+  OPENSSL_free(bn->d);
   bn->d = a;
   bn->dmax = words;
 

crypto/bn/convert.c

@@ -407,13 +407,9 @@ char *BN_bn2dec(const BIGNUM *a) {
   ok = 1;
 
 err:
-  if (bn_data != NULL) {
-    OPENSSL_free(bn_data);
-  }
-  if (t != NULL) {
-    BN_free(t);
-  }
-  if (!ok && buf) {
+  OPENSSL_free(bn_data);
+  BN_free(t);
+  if (!ok) {
     OPENSSL_free(buf);
     buf = NULL;
   }

crypto/bn/ctx.c

@@ -205,9 +205,7 @@ static void BN_STACK_init(BN_STACK *st) {
 }
 
 static void BN_STACK_finish(BN_STACK *st) {
-  if (st->size) {
-    OPENSSL_free(st->indexes);
-  }
+  OPENSSL_free(st->indexes);
 }
 
 static int BN_STACK_push(BN_STACK *st, unsigned int idx) {
@@ -222,9 +220,7 @@ static int BN_STACK_push(BN_STACK *st, unsigned int idx) {
     if (st->depth) {
       memcpy(newitems, st->indexes, st->depth * sizeof(unsigned int));
     }
-    if (st->size) {
-      OPENSSL_free(st->indexes);
-    }
+    OPENSSL_free(st->indexes);
     st->indexes = newitems;
     st->size = newsize;
   }

crypto/bn/div.c

@@ -492,9 +492,7 @@ int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m,
 
   ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m));
 
-  if (abs_m) {
-    BN_free(abs_m);
-  }
+  BN_free(abs_m);
   return ret;
 }
 

crypto/bn/exponentiation.c

@@ -763,7 +763,7 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
   ret = 1;
 
 err:
-  if (in_mont == NULL && mont != NULL) {
+  if (in_mont == NULL) {
     BN_MONT_CTX_free(mont);
   }
   BN_CTX_end(ctx);
@@ -878,8 +878,7 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
   BN_CTX_start(ctx);
 
   /* Allocate a montgomery context if it was not supplied by the caller.
-   * If this is not done, things will break in the montgomery part.
-   */
+   * If this is not done, things will break in the montgomery part. */
   if (in_mont != NULL) {
     mont = in_mont;
   } else {
@@ -1191,14 +1190,12 @@ int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
   }
   ret = 1;
 err:
-  if ((in_mont == NULL) && (mont != NULL)) {
+  if (in_mont == NULL) {
     BN_MONT_CTX_free(mont);
   }
   if (powerbuf != NULL) {
     OPENSSL_cleanse(powerbuf, powerbufLen);
-    if (powerbufFree) {
-      OPENSSL_free(powerbufFree);
-    }
+    OPENSSL_free(powerbufFree);
   }
   BN_CTX_end(ctx);
   return (ret);
@@ -1353,7 +1350,7 @@ int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
   ret = 1;
 
 err:
-  if (in_mont == NULL && mont != NULL) {
+  if (in_mont == NULL) {
     BN_MONT_CTX_free(mont);
   }
   BN_CTX_end(ctx);
@@ -1557,7 +1554,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1,
   ret = 1;
 
 err:
-  if (in_mont == NULL && mont != NULL) {
+  if (in_mont == NULL) {
     BN_MONT_CTX_free(mont);
   }
   BN_CTX_end(ctx);

crypto/bn/random.c

@@ -321,8 +321,6 @@ int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range, const BIGNUM *priv,
   ret = 1;
 
 err:
-  if (k_bytes) {
-    OPENSSL_free(k_bytes);
-  }
+  OPENSSL_free(k_bytes);
   return ret;
 }

crypto/bn/sqrt.c

@@ -420,7 +420,7 @@ vrfy:
 
 end:
   if (err) {
-    if (ret != NULL && ret != in) {
+    if (ret != in) {
       BN_clear_free(ret);
     }
     ret = NULL;

crypto/bytestring/cbb.c

@@ -66,7 +66,7 @@ int CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len) {
 
 void CBB_cleanup(CBB *cbb) {
   if (cbb->base) {
-    if (cbb->base->buf && cbb->base->can_resize) {
+    if (cbb->base->can_resize) {
       OPENSSL_free(cbb->base->buf);
     }
     OPENSSL_free(cbb->base);

crypto/bytestring/cbs.c

@@ -52,10 +52,8 @@ size_t CBS_len(const CBS *cbs) {
 }
 
 int CBS_stow(const CBS *cbs, uint8_t **out_ptr, size_t *out_len) {
-  if (*out_ptr != NULL) {
-    OPENSSL_free(*out_ptr);
-    *out_ptr = NULL;
-  }
+  OPENSSL_free(*out_ptr);
+  *out_ptr = NULL;
   *out_len = 0;
 
   if (cbs->len == 0) {

crypto/dh/dh.c

@@ -179,9 +179,7 @@ static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src) {
     }
   }
 
-  if (*dst) {
-    BN_free(*dst);
-  }
+  BN_free(*dst);
   *dst = a;
   return 1;
 }
@@ -204,11 +202,10 @@ static int int_dh_param_copy(DH *to, const DH *from, int is_x942) {
     return 0;
   }
 
-  if (to->seed) {
-    OPENSSL_free(to->seed);
-    to->seed = NULL;
-    to->seedlen = 0;
-  }
+  OPENSSL_free(to->seed);
+  to->seed = NULL;
+  to->seedlen = 0;
+
   if (from->seed) {
     to->seed = BUF_memdup(from->seed, from->seedlen);
     if (!to->seed) {

crypto/dh/dh_impl.c

@@ -245,10 +245,10 @@ err:
     OPENSSL_PUT_ERROR(DH, generate_key, ERR_R_BN_LIB);
   }
 
-  if (pub_key != NULL && dh->pub_key == NULL) {
+  if (dh->pub_key == NULL) {
     BN_free(pub_key);
   }
-  if (priv_key != NULL && dh->priv_key == NULL) {
+  if (dh->priv_key == NULL) {
     BN_free(priv_key);
   }
   BN_CTX_free(ctx);

crypto/dh/dh_test.c

@@ -189,18 +189,10 @@ int main(int argc, char *argv[]) {
 err:
   ERR_print_errors_fp(stderr);
 
-  if (abuf != NULL) {
-    OPENSSL_free(abuf);
-  }
-  if (bbuf != NULL) {
-    OPENSSL_free(bbuf);
-  }
-  if (b != NULL) {
-    DH_free(b);
-  }
-  if (a != NULL) {
-    DH_free(a);
-  }
+  OPENSSL_free(abuf);
+  OPENSSL_free(bbuf);
+  DH_free(b);
+  DH_free(a);
   return ret;
 }
 
@@ -493,18 +485,10 @@ bad_err:
   ERR_print_errors_fp(stderr);
 
 err:
-  if (Z1 != NULL) {
-    OPENSSL_free(Z1);
-  }
-  if (Z2 != NULL) {
-    OPENSSL_free(Z2);
-  }
-  if (dhA != NULL) {
-    DH_free(dhA);
-  }
-  if (dhB != NULL) {
-    DH_free(dhB);
-  }
+  OPENSSL_free(Z1);
+  OPENSSL_free(Z2);
+  DH_free(dhA);
+  DH_free(dhB);
 
   fprintf(stderr, "Test failed RFC5114 set %d\n", i + 1);
   return 0;

crypto/dsa/dsa.c

@@ -134,27 +134,13 @@ void DSA_free(DSA *dsa) {
 
   CRYPTO_free_ex_data(&g_ex_data_class, dsa, &dsa->ex_data);
 
-  if (dsa->p != NULL) {
-    BN_clear_free(dsa->p);
-  }
-  if (dsa->q != NULL) {
-    BN_clear_free(dsa->q);
-  }
-  if (dsa->g != NULL) {
-    BN_clear_free(dsa->g);
-  }
-  if (dsa->pub_key != NULL) {
-    BN_clear_free(dsa->pub_key);
-  }
-  if (dsa->priv_key != NULL) {
-    BN_clear_free(dsa->priv_key);
-  }
-  if (dsa->kinv != NULL) {
-    BN_clear_free(dsa->kinv);
-  }
-  if (dsa->r != NULL) {
-    BN_clear_free(dsa->r);
-  }
+  BN_clear_free(dsa->p);
+  BN_clear_free(dsa->q);
+  BN_clear_free(dsa->g);
+  BN_clear_free(dsa->pub_key);
+  BN_clear_free(dsa->priv_key);
+  BN_clear_free(dsa->kinv);
+  BN_clear_free(dsa->r);
   CRYPTO_MUTEX_cleanup(&dsa->method_mont_p_lock);
   OPENSSL_free(dsa);
 }
@@ -198,12 +184,8 @@ void DSA_SIG_free(DSA_SIG *sig) {
     return;
   }
 
-  if (sig->r) {
-    BN_free(sig->r);
-  }
-  if (sig->s) {
-    BN_free(sig->s);
-  }
+  BN_free(sig->r);
+  BN_free(sig->s);
   OPENSSL_free(sig);
 }
 
@@ -282,12 +264,8 @@ int DSA_check_signature(int *out_valid, const uint8_t *digest,
   ret = DSA_do_check_signature(out_valid, digest, digest_len, s, dsa);
 
 err:
-  if (der != NULL) {
-    OPENSSL_free(der);
-  }
-  if (s) {
-    DSA_SIG_free(s);
-  }
+  OPENSSL_free(der);
+  DSA_SIG_free(s);
   return ret;
 }
 
@@ -365,8 +343,6 @@ DH *DSA_dup_DH(const DSA *r) {
   return ret;
 
 err:
-  if (ret != NULL) {
-    DH_free(ret);
-  }
+  DH_free(ret);
   return NULL;
 }

crypto/dsa/dsa_impl.c

@@ -162,14 +162,10 @@ static int sign_setup(const DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
     goto err;
   }
 
-  if (*kinvp != NULL) {
-    BN_clear_free(*kinvp);
-  }
+  BN_clear_free(*kinvp);
   *kinvp = kinv;
   kinv = NULL;
-  if (*rp != NULL) {
-    BN_clear_free(*rp);
-  }
+  BN_clear_free(*rp);
   *rp = r;
   ret = 1;
 
@@ -277,15 +273,10 @@ err:
     BN_free(r);
     BN_free(s);
   }
-  if (ctx != NULL) {
-    BN_CTX_free(ctx);
-  }
+  BN_CTX_free(ctx);
   BN_clear_free(&m);
   BN_clear_free(&xr);
-  if (kinv != NULL) {
-    /* dsa->kinv is NULL now if we used it */
-    BN_clear_free(kinv);
-  }
+  BN_clear_free(kinv);
 
   return ret;
 }
@@ -392,9 +383,7 @@ err:
   if (ret != 1) {
     OPENSSL_PUT_ERROR(DSA, verify, ERR_R_BN_LIB);
   }
-  if (ctx != NULL) {
-    BN_CTX_free(ctx);
-  }
+  BN_CTX_free(ctx);
   BN_free(&u1);
   BN_free(&u2);
   BN_free(&t1);
@@ -447,15 +436,13 @@ static int keygen(DSA *dsa) {
   ok = 1;
 
 err:
-  if (pub_key != NULL && dsa->pub_key == NULL) {
+  if (dsa->pub_key == NULL) {
     BN_free(pub_key);
   }
-  if (priv_key != NULL && dsa->priv_key == NULL) {
+  if (dsa->priv_key == NULL) {
     BN_free(priv_key);
   }
-  if (ctx != NULL) {
-    BN_CTX_free(ctx);
-  }
+  BN_CTX_free(ctx);
 
   return ok;
 }
@@ -706,15 +693,9 @@ end:
 
 err:
   if (ok) {
-    if (ret->p) {
-      BN_free(ret->p);
-    }
-    if (ret->q) {
-      BN_free(ret->q);
-    }
-    if (ret->g) {
-      BN_free(ret->g);
-    }
+    BN_free(ret->p);
+    BN_free(ret->q);
+    BN_free(ret->g);
     ret->p = BN_dup(p);
     ret->q = BN_dup(q);
     ret->g = BN_dup(g);
@@ -735,9 +716,7 @@ err:
     BN_CTX_free(ctx);
   }
 
-  if (mont != NULL) {
-    BN_MONT_CTX_free(mont);
-  }
+  BN_MONT_CTX_free(mont);
 
   return ok;
 }

crypto/dsa/dsa_test.c

@@ -247,9 +247,7 @@ static int test_generate(FILE *out) {
   }
 
 end:
-  if (dsa != NULL) {
-    DSA_free(dsa);
-  }
+  DSA_free(dsa);
 
   return ok;
 }
@@ -271,9 +269,7 @@ static int test_verify(const uint8_t *sig, size_t sig_len, int expect) {
   ERR_clear_error();
 
 end:
-  if (dsa != NULL) {
-    DSA_free(dsa);
-  }
+  DSA_free(dsa);
 
   return ok;
 }