Always allocate a new stack in o2i_SCT_LIST().

If we're given a pointer to an existing stack, free it and allocate a new
one rather than poping and freeing all of the existing entries so we can
reuse it. While here rename some arguments and variables.

ok inoguchi@ tb@

1 files changed, 14 insertions, 19 deletions

diff --git a/src/lib/libcrypto/ct/ct_oct.c b/src/lib/libcrypto/ct/ct_oct.c
index 3dae7d8456..94e67c6bc3 100644
--- a/src/lib/libcrypto/ct/ct_oct.c
+++ b/src/lib/libcrypto/ct/ct_oct.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: ct_oct.c,v 1.7 2021/12/20 17:19:19 jsing Exp $ */
+/*      $OpenBSD: ct_oct.c,v 1.8 2021/12/20 17:23:07 jsing Exp $ */
 /*
  * Written by Rob Stradling (rob@comodo.com) and Stephen Henson
  * (steve@openssl.org) for the OpenSSL project 2014.
@@ -316,10 +316,10 @@ i2o_SCT(const SCT *sct, unsigned char **out)
 }
 
 STACK_OF(SCT) *
-o2i_SCT_LIST(STACK_OF(SCT) **scts, const unsigned char **pp, size_t len)
+o2i_SCT_LIST(STACK_OF(SCT) **out_scts, const unsigned char **pp, size_t len)
 {
         CBS cbs, cbs_scts, cbs_sct;
-        STACK_OF(SCT) *sk = NULL;
+        STACK_OF(SCT) *scts = NULL;
 
         CBS_init(&cbs, *pp, len);
 
@@ -330,18 +330,14 @@ o2i_SCT_LIST(STACK_OF(SCT) **scts, const unsigned char **pp, size_t len)
         if (CBS_len(&cbs) != 0)
                 goto err_invalid;
 
-        if (scts == NULL || *scts == NULL) {
-                if ((sk = sk_SCT_new_null()) == NULL)
-                        return NULL;
-        } else {
-                SCT *sct;
-
-                /* Use the given stack, but empty it first. */
-                sk = *scts;
-                while ((sct = sk_SCT_pop(sk)) != NULL)
-                        SCT_free(sct);
+        if (out_scts != NULL) {
+                SCT_LIST_free(*out_scts);
+                *out_scts = NULL;
         }
 
+        if ((scts = sk_SCT_new_null()) == NULL)
+                return NULL;
+
         while (CBS_len(&cbs_scts) > 0) {
                 SCT *sct;
 
@@ -350,24 +346,23 @@ o2i_SCT_LIST(STACK_OF(SCT) **scts, const unsigned char **pp, size_t len)
 
                 if (!o2i_SCT_internal(&sct, &cbs_sct))
                         goto err;
-                if (!sk_SCT_push(sk, sct)) {
+                if (!sk_SCT_push(scts, sct)) {
                         SCT_free(sct);
                         goto err;
                 }
         }
 
-        if (scts != NULL && *scts == NULL)
-                *scts = sk;
+        if (out_scts != NULL)
+                *out_scts = scts;
 
         *pp = CBS_data(&cbs);
 
-        return sk;
+        return scts;
 
  err_invalid:
         CTerror(CT_R_SCT_LIST_INVALID);
  err:
-        if (scts == NULL || *scts == NULL)
-                SCT_LIST_free(sk);
+        SCT_LIST_free(scts);
 
         return NULL;
 }