Change to check last return value of BN_CTX_get

To make it consistent in the code base

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/3749)

9 files changed, 32 insertions, 47 deletions

diff --git a/crypto/bn/bn_div.c b/crypto/bn/bn_div.c
index 5e620b2096..bd49e07dbc 100644
--- a/crypto/bn/bn_div.c
+++ b/crypto/bn/bn_div.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -191,14 +191,11 @@ int BN_div(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, const BIGNUM *divisor,
     }
 
     BN_CTX_start(ctx);
+    res = (dv == NULL) ? BN_CTX_get(ctx) : dv;
     tmp = BN_CTX_get(ctx);
     snum = BN_CTX_get(ctx);
     sdiv = BN_CTX_get(ctx);
-    if (dv == NULL)
-        res = BN_CTX_get(ctx);
-    else
-        res = dv;
-    if (sdiv == NULL || res == NULL || tmp == NULL || snum == NULL)
+    if (sdiv == NULL)
         goto err;
 
     /* First we normalise the numbers */
diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c
index 5e6bb4474f..72d6cad910 100644
--- a/crypto/bn/bn_exp.c
+++ b/crypto/bn/bn_exp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -50,10 +50,7 @@ int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
     }
 
     BN_CTX_start(ctx);
-    if ((r == a) || (r == p))
-        rr = BN_CTX_get(ctx);
-    else
-        rr = r;
+    rr = ((r == a) || (r == p)) ? BN_CTX_get(ctx) : r;
     v = BN_CTX_get(ctx);
     if (rr == NULL || v == NULL)
         goto err;
@@ -85,7 +82,7 @@ int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
  err:
     BN_CTX_end(ctx);
     bn_check_top(r);
-    return (ret);
+    return ret;
 }
 
 int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
@@ -189,7 +186,7 @@ int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     BN_CTX_start(ctx);
     aa = BN_CTX_get(ctx);
     val[0] = BN_CTX_get(ctx);
-    if (!aa || !val[0])
+    if (val[0] == NULL)
         goto err;
 
     BN_RECP_CTX_init(&recp);
@@ -330,7 +327,7 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
     d = BN_CTX_get(ctx);
     r = BN_CTX_get(ctx);
     val[0] = BN_CTX_get(ctx);
-    if (!d || !r || !val[0])
+    if (val[0] == NULL)
         goto err;
 
     /*
@@ -1095,7 +1092,7 @@ int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
     int b, bits, ret = 0;
     int r_is_one;
     BN_ULONG w, next_w;
-    BIGNUM *d, *r, *t;
+    BIGNUM *r, *t;
     BIGNUM *swap_tmp;
 #define BN_MOD_MUL_WORD(r, w, m) \
                 (BN_mul_word(r, (w)) && \
@@ -1148,10 +1145,9 @@ int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
     }
 
     BN_CTX_start(ctx);
-    d = BN_CTX_get(ctx);
     r = BN_CTX_get(ctx);
     t = BN_CTX_get(ctx);
-    if (d == NULL || r == NULL || t == NULL)
+    if (t == NULL)
         goto err;
 
     if (in_mont != NULL)
@@ -1266,7 +1262,7 @@ int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     BN_CTX_start(ctx);
     d = BN_CTX_get(ctx);
     val[0] = BN_CTX_get(ctx);
-    if (!d || !val[0])
+    if (val[0] == NULL)
         goto err;
 
     if (!BN_nnmod(val[0], a, m, ctx))
diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c
index 5141c21f6d..2fc71b4e53 100644
--- a/crypto/bn/bn_exp2.c
+++ b/crypto/bn/bn_exp2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -50,7 +50,7 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1,
     r = BN_CTX_get(ctx);
     val1[0] = BN_CTX_get(ctx);
     val2[0] = BN_CTX_get(ctx);
-    if (!d || !r || !val1[0] || !val2[0])
+    if (val2[0] == NULL)
         goto err;
 
     if (in_mont != NULL)
diff --git a/crypto/bn/bn_gcd.c b/crypto/bn/bn_gcd.c
index 067642644e..ba41bc72d4 100644
--- a/crypto/bn/bn_gcd.c
+++ b/crypto/bn/bn_gcd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -23,7 +23,7 @@ int BN_gcd(BIGNUM *r, const BIGNUM *in_a, const BIGNUM *in_b, BN_CTX *ctx)
     BN_CTX_start(ctx);
     a = BN_CTX_get(ctx);
     b = BN_CTX_get(ctx);
-    if (a == NULL || b == NULL)
+    if (b == NULL)
         goto err;
 
     if (BN_copy(a, in_a) == NULL)
diff --git a/crypto/bn/bn_gf2m.c b/crypto/bn/bn_gf2m.c
index c118b39be8..39b0e3849f 100644
--- a/crypto/bn/bn_gf2m.c
+++ b/crypto/bn/bn_gf2m.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2002-2017 The OpenSSL Project Authors. All Rights Reserved.
  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
@@ -557,13 +557,11 @@ int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
 
     BN_CTX_start(ctx);
 
-    if ((b = BN_CTX_get(ctx)) == NULL)
-        goto err;
-    if ((c = BN_CTX_get(ctx)) == NULL)
-        goto err;
-    if ((u = BN_CTX_get(ctx)) == NULL)
-        goto err;
-    if ((v = BN_CTX_get(ctx)) == NULL)
+    b = BN_CTX_get(ctx);
+    c = BN_CTX_get(ctx);
+    u = BN_CTX_get(ctx);
+    v = BN_CTX_get(ctx);
+    if (v == NULL)
         goto err;
 
     if (!BN_GF2m_mod(u, a, p))
diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index 6d37279a5e..9dad113d02 100644
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -180,7 +180,7 @@ int BN_from_montgomery(BIGNUM *ret, const BIGNUM *a, BN_MONT_CTX *mont,
     BN_CTX_start(ctx);
     t1 = BN_CTX_get(ctx);
     t2 = BN_CTX_get(ctx);
-    if (t1 == NULL || t2 == NULL)
+    if (t2 == NULL)
         goto err;
 
     if (!BN_copy(t1, a))
diff --git a/crypto/bn/bn_recp.c b/crypto/bn/bn_recp.c
index 20585b9d4b..80bfa2d38b 100644
--- a/crypto/bn/bn_recp.c
+++ b/crypto/bn/bn_recp.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -87,17 +87,11 @@ int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
     BIGNUM *a, *b, *d, *r;
 
     BN_CTX_start(ctx);
+    d = (dv != NULL) ? dv : BN_CTX_get(ctx);
+    r = (rem != NULL) ? rem : BN_CTX_get(ctx);
     a = BN_CTX_get(ctx);
     b = BN_CTX_get(ctx);
-    if (dv != NULL)
-        d = dv;
-    else
-        d = BN_CTX_get(ctx);
-    if (rem != NULL)
-        r = rem;
-    else
-        r = BN_CTX_get(ctx);
-    if (a == NULL || b == NULL || d == NULL || r == NULL)
+    if (b == NULL)
         goto err;
 
     if (BN_ucmp(m, &(recp->N)) < 0) {
diff --git a/crypto/bn/bn_sqr.c b/crypto/bn/bn_sqr.c
index 44e7332acf..4e8df0e3ec 100644
--- a/crypto/bn/bn_sqr.c
+++ b/crypto/bn/bn_sqr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -32,7 +32,7 @@ int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
     BN_CTX_start(ctx);
     rr = (a != r) ? r : BN_CTX_get(ctx);
     tmp = BN_CTX_get(ctx);
-    if (!rr || !tmp)
+    if (rr == NULL || tmp == NULL)
         goto err;
 
     max = 2 * al;               /* Non-zero (from above) */
diff --git a/crypto/bn/bn_x931p.c b/crypto/bn/bn_x931p.c
index 8bfbcac6a4..17bc8c73ca 100644
--- a/crypto/bn/bn_x931p.c
+++ b/crypto/bn/bn_x931p.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -62,10 +62,10 @@ int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2,
         return 0;
 
     BN_CTX_start(ctx);
-    if (!p1)
+    if (p1 == NULL)
         p1 = BN_CTX_get(ctx);
 
-    if (!p2)
+    if (p2 == NULL)
         p2 = BN_CTX_get(ctx);
 
     t = BN_CTX_get(ctx);