Rework asn1_item_flags_i2d()

Flip the logic of NULL checks on out and *out to unindent, use calloc()
instead of malloc() and check on assign. Also drop the newly added len2
again, it isn't needed.

ok jsing

diff --git a/lib/libcrypto/asn1/tasn_enc.c b/lib/libcrypto/asn1/tasn_enc.c
index 1b9cfa1..6e0524c 100644 (file)
--- a/lib/libcrypto/asn1/tasn_enc.c
+++ b/lib/libcrypto/asn1/tasn_enc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tasn_enc.c,v 1.28 2023/03/06 08:08:31 tb Exp $ */
+/* $OpenBSD: tasn_enc.c,v 1.29 2023/03/06 12:00:27 tb Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2000.
  */
@@ -106,27 +106,28 @@ static int
 asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it,
     int flags)
 {
-       if (out && !*out) {
-               unsigned char *p, *buf;
-               int len, len2;
-               len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags);
-               if (len <= 0)
-                       return len;
-               buf = malloc(len);
-               if (!buf)
-                       return -1;
-               p = buf;
-               len2 = ASN1_item_ex_i2d(&val, &p, it, -1, flags);
-               if (len2 != len) {
-                       freezero(buf, len);
-                       ASN1error(ASN1_R_LENGTH_ERROR);
-                       return -1;
-               }
-               *out = buf;
+       unsigned char *p, *buf;
+       int len;
+
+       if (out == NULL || *out != NULL)
+               return ASN1_item_ex_i2d(&val, out, it, -1, flags);
+
+       if ((len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags)) <= 0)
                return len;
+
+       if ((buf = calloc(1, len)) == NULL)
+               return -1;
+
+       p = buf;
+       if (ASN1_item_ex_i2d(&val, &p, it, -1, flags) != len) {
+               freezero(buf, len);
+               ASN1error(ASN1_R_LENGTH_ERROR);
+               return -1;
        }
 
-       return ASN1_item_ex_i2d(&val, out, it, -1, flags);
+       *out = buf;
+
+       return len;
 }
 
 /* Encode an item, taking care of IMPLICIT tagging (if any).