Address some signed vs unsigned warnings and check that an integer value

is positive before passing it to several functions as a size_t.
Additionally, in tls_load_file() there is not much point using calloc(),
when we're immediately reading into the buffer (having an extra byte for
NUL termination seems pointless given the API).

ok beck@ miod@

1 files changed, 14 insertions, 4 deletions

diff --git a/src/lib/libtls/tls_util.c b/src/lib/libtls/tls_util.c
index 8cf3345caf..dbb2d170d5 100644
--- a/src/lib/libtls/tls_util.c
+++ b/src/lib/libtls/tls_util.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: tls_util.c,v 1.4 2016/10/03 04:13:58 bcook Exp $ */
+/* $OpenBSD: tls_util.c,v 1.5 2016/11/04 15:59:16 jsing Exp $ */
 /*
  * Copyright (c) 2014 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2015 Reyk Floeter <reyk@openbsd.org>
@@ -89,13 +89,19 @@ tls_host_port(const char *hostport, char **host, char **port)
 static int
 tls_password_cb(char *buf, int size, int rwflag, void *u)
 {
-        size_t  len;
+        size_t len;
+
+        if (size < 0)
+                return (0);
+
         if (u == NULL) {
                 memset(buf, 0, size);
                 return (0);
         }
+
         if ((len = strlcpy(buf, u, size)) >= (size_t)size)
                 return (0);
+
         return (len);
 }
 
@@ -110,6 +116,7 @@ tls_load_file(const char *name, size_t *len, char *password)
         struct stat st;
         size_t size;
         int fd = -1;
+        ssize_t n;
 
         *len = 0;
 
@@ -120,10 +127,13 @@ tls_load_file(const char *name, size_t *len, char *password)
         if (password == NULL) {
                 if (fstat(fd, &st) != 0)
                         goto fail;
+                if (st.st_size < 0)
+                        goto fail;
                 size = (size_t)st.st_size;
-                if ((buf = calloc(1, size + 1)) == NULL)
+                if ((buf = malloc(size)) == NULL)
                         goto fail;
-                if (read(fd, buf, size) != size)
+                n = read(fd, buf, size);
+                if (n < 0 || (size_t)n != size)
                         goto fail;
                 close(fd);
                 goto done;