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, 16 insertions, 11 deletions

diff --git a/monitor.c b/monitor.c
index 6b780e480..dce920c23 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.158 2016/03/07 19:02:43 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.159 2016/05/02 08:49:03 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -34,6 +34,7 @@
 
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #ifdef HAVE_PATHS_H
 #include <paths.h>
 #endif
@@ -688,7 +689,8 @@ mm_answer_sign(int sock, Buffer *m)
         u_char *p = NULL, *signature = NULL;
         char *alg = NULL;
         size_t datlen, siglen, alglen;
-        int r, keyid, is_proof = 0;
+        int r, is_proof = 0;
+        u_int keyid;
         const char proof_req[] = "hostkeys-prove-00@openssh.com";
 
         debug3("%s", __func__);
@@ -697,6 +699,8 @@ mm_answer_sign(int sock, Buffer *m)
             (r = sshbuf_get_string(m, &p, &datlen)) != 0 ||
             (r = sshbuf_get_cstring(m, &alg, &alglen)) != 0)
                 fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        if (keyid > INT_MAX)
+                fatal("%s: invalid key ID", __func__);
 
         /*
          * Supported KEX types use SHA1 (20 bytes), SHA256 (32 bytes),
@@ -1289,7 +1293,8 @@ static int
 monitor_valid_userblob(u_char *data, u_int datalen)
 {
         Buffer b;
-        char *p, *userstyle;
+        u_char *p;
+        char *userstyle, *cp;
         u_int len;
         int fail = 0;
 
@@ -1314,26 +1319,26 @@ monitor_valid_userblob(u_char *data, u_int datalen)
         }
         if (buffer_get_char(&b) != SSH2_MSG_USERAUTH_REQUEST)
                 fail++;
-        p = buffer_get_cstring(&b, NULL);
+        cp = buffer_get_cstring(&b, NULL);
         xasprintf(&userstyle, "%s%s%s", authctxt->user,
             authctxt->style ? ":" : "",
             authctxt->style ? authctxt->style : "");
-        if (strcmp(userstyle, p) != 0) {
-                logit("wrong user name passed to monitor: expected %s != %.100s",
-                    userstyle, p);
+        if (strcmp(userstyle, cp) != 0) {
+                logit("wrong user name passed to monitor: "
+                    "expected %s != %.100s", userstyle, cp);
                 fail++;
         }
         free(userstyle);
-        free(p);
+        free(cp);
         buffer_skip_string(&b);
         if (datafellows & SSH_BUG_PKAUTH) {
                 if (!buffer_get_char(&b))
                         fail++;
         } else {
-                p = buffer_get_cstring(&b, NULL);
-                if (strcmp("publickey", p) != 0)
+                cp = buffer_get_cstring(&b, NULL);
+                if (strcmp("publickey", cp) != 0)
                         fail++;
-                free(p);
+                free(cp);
                 if (!buffer_get_char(&b))
                         fail++;
                 buffer_skip_string(&b);