From: jsing <jsing@openbsd.org>
Date: Thu, 12 May 2022 20:06:46 +0000 (+0000)
Subject: Call the ASN1_OP_D2I_PRE callback after ASN1_item_ex_new().
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=2960f0cd6c4b256952c3f9c8db9fde74fc28e7f8;p=openbsd

Call the ASN1_OP_D2I_PRE callback after ASN1_item_ex_new().

In asn1_item_ex_d2i_choice(), only call the ASN1_OP_D2I_PRE callback after
allocation has occurred via ASN1_item_ex_new(). This matches the sequence
handling code and the documentation.

Discussed with tb@
---

diff --git a/lib/libcrypto/asn1/tasn_dec.c b/lib/libcrypto/asn1/tasn_dec.c
index db4424b6bea..48ac38a883b 100644
--- a/lib/libcrypto/asn1/tasn_dec.c
+++ b/lib/libcrypto/asn1/tasn_dec.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tasn_dec.c,v 1.66 2022/05/12 19:52:31 jsing Exp $ */
+/* $OpenBSD: tasn_dec.c,v 1.67 2022/05/12 20:06:46 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -135,6 +135,9 @@ asn1_item_ex_d2i_choice(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
 	ASN1_VALUE **pchptr;
 	int i, ret;
 
+	if (aux != NULL)
+		asn1_cb = aux->asn1_cb;
+
 	if (it->itype != ASN1_ITYPE_CHOICE)
 		goto err;
 
@@ -152,21 +155,16 @@ asn1_item_ex_d2i_choice(ASN1_VALUE **pval, CBS *cbs, const ASN1_ITEM *it,
 		*pval = NULL;
 	}
 
-	if (aux != NULL)
-		asn1_cb = aux->asn1_cb;
+	if (!ASN1_item_ex_new(&achoice, it)) {
+		ASN1error(ERR_R_NESTED_ASN1_ERROR);
+		goto err;
+	}
 
 	if (asn1_cb != NULL && !asn1_cb(ASN1_OP_D2I_PRE, &achoice, it, NULL)) {
 		ASN1error(ASN1_R_AUX_ERROR);
 		goto err;
 	}
 
-	if (achoice == NULL) {
-		if (!ASN1_item_ex_new(&achoice, it)) {
-			ASN1error(ERR_R_NESTED_ASN1_ERROR);
-			goto err;
-		}
-	}
-
 	/* Try each possible CHOICE in turn. */
 	for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
 		pchptr = asn1_get_field_ptr(&achoice, tt);