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@

diff --git a/lib/libcrypto/ct/ct_oct.c b/lib/libcrypto/ct/ct_oct.c
index 3dae7d8..94e67c6 100644 (file)
--- a/lib/libcrypto/ct/ct_oct.c
+++ b/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;
 }