Simplify RSA_setup_blinding()

Make this look a bit more like other code we cleaned up avoiding nesting
and unnecessary else branches.

ok jsing

1 files changed, 16 insertions, 21 deletions

diff --git a/src/lib/libcrypto/rsa/rsa_crpt.c b/src/lib/libcrypto/rsa/rsa_crpt.c
index 15108e24f0..a53ec54b32 100644
--- a/src/lib/libcrypto/rsa/rsa_crpt.c
+++ b/src/lib/libcrypto/rsa/rsa_crpt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_crpt.c,v 1.23 2023/07/28 10:05:16 tb Exp $ */
+/* $OpenBSD: rsa_crpt.c,v 1.24 2023/08/08 13:49:45 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -187,44 +187,39 @@ err:
 BN_BLINDING *
 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
 {
-        BIGNUM *e;
+        BIGNUM *e = NULL;
         BIGNUM n;
-        BN_CTX *ctx;
+        BN_CTX *ctx = NULL;
         BN_BLINDING *ret = NULL;
 
-        if (in_ctx == NULL) {
-                if ((ctx = BN_CTX_new()) == NULL)
-                        return 0;
-        } else
-                ctx = in_ctx;
+        if ((ctx = in_ctx) == NULL)
+                ctx = BN_CTX_new();
+        if (ctx == NULL)
+                goto err;
 
         BN_CTX_start(ctx);
 
-        if (rsa->e == NULL) {
+        if ((e = rsa->e) == NULL)
                 e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
-                if (e == NULL) {
-                        RSAerror(RSA_R_NO_PUBLIC_EXPONENT);
-                        goto err;
-                }
-        } else
-                e = rsa->e;
+        if (e == NULL) {
+                RSAerror(RSA_R_NO_PUBLIC_EXPONENT);
+                goto err;
+        }
 
         BN_init(&n);
         BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME);
 
-        ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp,
-            rsa->_method_mod_n);
-
-        if (ret == NULL) {
+        if ((ret = BN_BLINDING_create_param(NULL, e, &n, ctx,
+            rsa->meth->bn_mod_exp, rsa->_method_mod_n)) == NULL) {
                 RSAerror(ERR_R_BN_LIB);
                 goto err;
         }
         CRYPTO_THREADID_current(BN_BLINDING_thread_id(ret));
 err:
         BN_CTX_end(ctx);
-        if (in_ctx == NULL)
+        if (ctx != in_ctx)
                 BN_CTX_free(ctx);
-        if (rsa->e == NULL)
+        if (e != rsa->e)
                 BN_free(e);
 
         return ret;