- OpenBSD CVS Sync

   - djm@cvs.openbsd.org 2010/03/03 01:44:36
     [auth-options.c key.c]
     reject strings with embedded ASCII nul chars in certificate key IDs,
     principal names and constraints

1 files changed, 20 insertions, 8 deletions

diff --git a/auth-options.c b/auth-options.c
index 396bda62f..d14624bf4 100644
--- a/auth-options.c
+++ b/auth-options.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth-options.c,v 1.45 2010/02/26 20:29:54 djm Exp $ */
+/* $OpenBSD: auth-options.c,v 1.46 2010/03/03 01:44:36 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -391,7 +391,7 @@ int
 auth_cert_constraints(Buffer *c_orig, struct passwd *pw)
 {
         u_char *name = NULL, *data_blob = NULL;
-        u_int len;
+        u_int nlen, dlen, clen;
         Buffer c, data;
         int ret = -1;
 
@@ -410,14 +410,18 @@ auth_cert_constraints(Buffer *c_orig, struct passwd *pw)
         buffer_append(&c, buffer_ptr(c_orig), buffer_len(c_orig));
 
         while (buffer_len(&c) > 0) {
-                if ((name = buffer_get_string_ret(&c, NULL)) == NULL ||
-                    (data_blob = buffer_get_string_ret(&c, &len)) == NULL) {
+                if ((name = buffer_get_string_ret(&c, &nlen)) == NULL ||
+                    (data_blob = buffer_get_string_ret(&c, &dlen)) == NULL) {
                         error("Certificate constraints corrupt");
                         goto out;
                 }
-                buffer_append(&data, data_blob, len);
+                buffer_append(&data, data_blob, dlen);
                 debug3("found certificate constraint \"%.100s\" len %u",
-                    name, len);
+                    name, dlen);
+                if (strlen(name) != nlen) {
+                        error("Certificate constraint name contains \\0");
+                        goto out;
+                }
                 if (strcmp(name, "permit-X11-forwarding") == 0)
                         cert_no_x11_forwarding_flag = 0;
                 else if (strcmp(name, "permit-agent-forwarding") == 0)
@@ -429,13 +433,17 @@ auth_cert_constraints(Buffer *c_orig, struct passwd *pw)
                 else if (strcmp(name, "permit-user-rc") == 0)
                         cert_no_user_rc = 0;
                 else if (strcmp(name, "force-command") == 0) {
-                        char *command = buffer_get_string_ret(&data, NULL);
+                        char *command = buffer_get_string_ret(&data, &clen);
 
                         if (command == NULL) {
                                 error("Certificate constraint \"%s\" corrupt",
                                     name);
                                 goto out;
                         }
+                        if (strlen(command) != clen) {
+                                error("force-command constrain contains \\0");
+                                goto out;
+                        }
                         if (cert_forced_command != NULL) {
                                 error("Certificate has multiple "
                                     "forced-command constraints");
@@ -444,7 +452,7 @@ auth_cert_constraints(Buffer *c_orig, struct passwd *pw)
                         }
                         cert_forced_command = command;
                 } else if (strcmp(name, "source-address") == 0) {
-                        char *allowed = buffer_get_string_ret(&data, NULL);
+                        char *allowed = buffer_get_string_ret(&data, &clen);
                         const char *remote_ip = get_remote_ipaddr();
                         
                         if (allowed == NULL) {
@@ -452,6 +460,10 @@ auth_cert_constraints(Buffer *c_orig, struct passwd *pw)
                                     name);
                                 goto out;
                         }
+                        if (strlen(allowed) != clen) {
+                                error("source-address constrain contains \\0");
+                                goto out;
+                        }
                         if (cert_source_address_done++) {
                                 error("Certificate has multiple "
                                     "source-address constraints");