Simplify RSA_setup_blinding()

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

ok jsing

diff --git a/lib/libcrypto/rsa/rsa_crpt.c b/lib/libcrypto/rsa/rsa_crpt.c
index 15108e2..a53ec54 100644 (file)
--- a/lib/libcrypto/rsa/rsa_crpt.c
+++ b/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;