upstream commit

fix signed/unsigned errors reported by clang-3.7; add
 sshbuf_dup_string() to replace a common idiom of strdup(sshbuf_ptr()) with
 better safety checking; feedback and ok markus@

Upstream-ID: 71f926d9bb3f1efed51319a6daf37e93d57c8820

1 files changed, 24 insertions, 1 deletions

diff --git a/sshbuf-misc.c b/sshbuf-misc.c
index 3da4b80e7..15dcfbc79 100644
--- a/sshbuf-misc.c
+++ b/sshbuf-misc.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sshbuf-misc.c,v 1.5 2015/10/05 17:11:21 djm Exp $     */
+/*      $OpenBSD: sshbuf-misc.c,v 1.6 2016/05/02 08:49:03 djm Exp $     */
 /*
  * Copyright (c) 2011 Damien Miller
  *
@@ -136,3 +136,26 @@ sshbuf_b64tod(struct sshbuf *buf, const char *b64)
         return 0;
 }
 
+char *
+sshbuf_dup_string(struct sshbuf *buf)
+{
+        const u_char *p = NULL, *s = sshbuf_ptr(buf);
+        size_t l = sshbuf_len(buf);
+        char *r;
+
+        if (s == NULL || l > SIZE_MAX)
+                return NULL;
+        /* accept a nul only as the last character in the buffer */
+        if (l > 0 && (p = memchr(s, '\0', l)) != NULL) {
+                if (p != s + l - 1)
+                        return NULL;
+                l--; /* the nul is put back below */
+        }
+        if ((r = malloc(l + 1)) == NULL)
+                return NULL;
+        if (l > 0)
+                memcpy(r, s, l);
+        r[l] = '\0';
+        return r;
+}
+