svn commit: r322341 - in stable: 10/crypto/openssh 11/crypto/openssh

[Xin LI]

Author: delphij
Date: Thu Aug 10 06:36:37 2017
New Revision: 322341
URL: https://svnweb.freebsd.org/changeset/base/322341

Log:
  Apply upstream fix:
  
  Skip passwords longer than 1k in length so clients can't
  easily DoS sshd by sending very long passwords, causing it to spend CPU
  hashing them. feedback djm@, ok markus at .
  
  Brought to our attention by tomas.kuthan at oracle.com, shilei-c at
  360.cn and coredump at autistici.org
  
  Security:	CVE-2016-6515
  Security:	FreeBSD-SA-17:06.openssh

Modified:
  stable/11/crypto/openssh/auth-passwd.c

Changes in other areas also in this revision:
Modified:
  stable/10/crypto/openssh/auth-passwd.c

Modified: stable/11/crypto/openssh/auth-passwd.c
==============================================================================
--- stable/11/crypto/openssh/auth-passwd.c	Thu Aug 10 05:38:31 2017	(r322340)
+++ stable/11/crypto/openssh/auth-passwd.c	Thu Aug 10 06:36:37 2017	(r322341)
@@ -66,6 +66,8 @@ extern login_cap_t *lc;
 #define DAY		(24L * 60 * 60) /* 1 day in seconds */
 #define TWO_WEEKS	(2L * 7 * DAY)	/* 2 weeks in seconds */
 
+#define MAX_PASSWORD_LEN	1024
+
 void
 disable_forwarding(void)
 {
@@ -86,6 +88,9 @@ auth_password(Authctxt *authctxt, const char *password
 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
 	static int expire_checked = 0;
 #endif
+
+	if (strlen(password) > MAX_PASSWORD_LEN)
+		return 0;
 
 #ifndef HAVE_CYGWIN
 	if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)