Prepare further fixes of X509_ALGOR_set0() misuse

In rsa_alg_set_oaep_padding() rename los to ostr for consistency with
astr, make it have function scope, free ostr in the error path and assume
X509_ALGOR_set0() success.

ok jca

1 files changed, 7 insertions, 8 deletions

diff --git a/src/lib/libcrypto/rsa/rsa_ameth.c b/src/lib/libcrypto/rsa/rsa_ameth.c
index 0558144dc7..cbdf7a36e9 100644
--- a/src/lib/libcrypto/rsa/rsa_ameth.c
+++ b/src/lib/libcrypto/rsa/rsa_ameth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_ameth.c,v 1.47 2023/11/08 17:07:07 tb Exp $ */
+/* $OpenBSD: rsa_ameth.c,v 1.48 2023/11/08 19:14:43 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -914,6 +914,7 @@ rsa_alg_set_oaep_padding(X509_ALGOR *alg, EVP_PKEY_CTX *pkey_ctx)
         const EVP_MD *md, *mgf1md;
         RSA_OAEP_PARAMS *oaep = NULL;
         ASN1_STRING *astr = NULL;
+        ASN1_OCTET_STRING *ostr = NULL;
         unsigned char *label;
         int labellen;
         int ret = 0;
@@ -937,19 +938,16 @@ rsa_alg_set_oaep_padding(X509_ALGOR *alg, EVP_PKEY_CTX *pkey_ctx)
         /* XXX - why do we not set oaep->maskHash here? */
 
         if (labellen > 0) {
-                ASN1_OCTET_STRING *los;
                 oaep->pSourceFunc = X509_ALGOR_new();
                 if (oaep->pSourceFunc == NULL)
                         goto err;
-                los = ASN1_OCTET_STRING_new();
-                if (los == NULL)
+                if ((ostr = ASN1_OCTET_STRING_new()) == NULL)
                         goto err;
-                if (!ASN1_OCTET_STRING_set(los, label, labellen)) {
-                        ASN1_OCTET_STRING_free(los);
+                if (!ASN1_OCTET_STRING_set(ostr, label, labellen))
                         goto err;
-                }
                 X509_ALGOR_set0(oaep->pSourceFunc, OBJ_nid2obj(NID_pSpecified),
-                    V_ASN1_OCTET_STRING, los);
+                    V_ASN1_OCTET_STRING, ostr);
+                ostr = NULL;
         }
         /* create string with pss parameter encoding. */
         if ((astr = ASN1_item_pack(oaep, &RSA_OAEP_PARAMS_it, NULL)) == NULL)
@@ -962,6 +960,7 @@ rsa_alg_set_oaep_padding(X509_ALGOR *alg, EVP_PKEY_CTX *pkey_ctx)
  err:
         RSA_OAEP_PARAMS_free(oaep);
         ASN1_STRING_free(astr);
+        ASN1_OCTET_STRING_free(ostr);
 
         return ret;
 }