upstream: Make sshpkt_get_bignum2() allocate the bignum it is

parsing rather than make the caller do it. Saves a lot of boilerplate code.

from markus@ ok djm@

OpenBSD-Commit-ID: 576bf784f9a240f5a1401f7005364e59aed3bce9

1 files changed, 13 insertions, 4 deletions

diff --git a/sshbuf-getput-crypto.c b/sshbuf-getput-crypto.c
index a49b72ef7..3dd1e1446 100644
--- a/sshbuf-getput-crypto.c
+++ b/sshbuf-getput-crypto.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf-getput-crypto.c,v 1.6 2019/01/21 09:52:25 djm Exp $    */
+/*      $OpenBSD: sshbuf-getput-crypto.c,v 1.7 2019/01/21 09:54:11 djm Exp $    */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -32,16 +32,25 @@
 #include "sshbuf.h"
 
 int
-sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM *v)
+sshbuf_get_bignum2(struct sshbuf *buf, BIGNUM **valp)
 {
+        BIGNUM *v;
         const u_char *d;
         size_t len;
         int r;
 
+        if (valp != NULL)
+                *valp = NULL;
         if ((r = sshbuf_get_bignum2_bytes_direct(buf, &d, &len)) != 0)
                 return r;
-        if (v != NULL && BN_bin2bn(d, len, v) == NULL)
-                return SSH_ERR_ALLOC_FAIL;
+        if (valp != NULL) {
+                if ((v = BN_new()) == NULL ||
+                    BN_bin2bn(d, len, v) == NULL) {
+                        BN_clear_free(v);
+                        return SSH_ERR_ALLOC_FAIL;
+                }
+                *valp = v;
+        }
         return 0;
 }