- OpenBSD CVS Sync

   - djm@cvs.openbsd.org 2010/02/26 20:29:54
     [PROTOCOL PROTOCOL.agent PROTOCOL.certkeys addrmatch.c auth-options.c]
     [auth-options.h auth.h auth2-pubkey.c authfd.c dns.c dns.h hostfile.c]
     [hostfile.h kex.h kexdhs.c kexgexs.c key.c key.h match.h monitor.c]
     [myproposal.h servconf.c servconf.h ssh-add.c ssh-agent.c ssh-dss.c]
     [ssh-keygen.1 ssh-keygen.c ssh-rsa.c ssh.1 ssh.c ssh2.h sshconnect.c]
     [sshconnect2.c sshd.8 sshd.c sshd_config.5]
     Add support for certificate key types for users and hosts.

     OpenSSH certificate key types are not X.509 certificates, but a much
     simpler format that encodes a public key, identity information and
     some validity constraints and signs it with a CA key. CA keys are
     regular SSH keys. This certificate style avoids the attack surface
     of X.509 certificates and is very easy to deploy.

     Certified host keys allow automatic acceptance of new host keys
     when a CA certificate is marked as sh/known_hosts.
     see VERIFYING HOST KEYS in ssh(1) for details.

     Certified user keys allow authentication of users when the signing
     CA key is marked as trusted in authorized_keys. See "AUTHORIZED_KEYS
     FILE FORMAT" in sshd(8) for details.

     Certificates are minted using ssh-keygen(1), documentation is in
     the "CERTIFICATES" section of that manpage.

     Documentation on the format of certificates is in the file
     PROTOCOL.certkeys

     feedback and ok markus@

1 files changed, 27 insertions, 4 deletions

diff --git a/hostfile.c b/hostfile.c
index cd28bf44..fc7f84c7 100644
--- a/hostfile.c
+++ b/hostfile.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hostfile.c,v 1.46 2009/10/11 23:03:15 djm Exp $ */
+/* $OpenBSD: hostfile.c,v 1.47 2010/02/26 20:29:54 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -199,7 +199,7 @@ check_host_in_hostfile_by_key_or_type(const char *filename,
 {
 	FILE *f;
 	char line[8192];
-	int linenum = 0;
+	int linenum = 0, want_cert = key_is_cert(key);
 	u_int kbits;
 	char *cp, *cp2, *hashed_host;
 	HostStatus end_return;
@@ -229,6 +229,23 @@ check_host_in_hostfile_by_key_or_type(const char *filename,
 		if (!*cp || *cp == '#' || *cp == '\n')
 			continue;
 
+		/*
+		 * Ignore CA keys when looking for raw keys.
+		 * Ignore raw keys when looking for CA keys.
+		 */
+		if (strncasecmp(cp, CA_MARKER, sizeof(CA_MARKER) - 1) == 0 &&
+		    (cp[sizeof(CA_MARKER) - 1] == ' ' ||
+		    cp[sizeof(CA_MARKER) - 1] == '\t')) {
+			if (want_cert) {
+				/* Skip the marker and following whitespace */
+				cp += sizeof(CA_MARKER);
+				for (; *cp == ' ' || *cp == '\t'; cp++)
+					;
+			} else
+				continue;
+		} else if (want_cert)
+			continue;
+
 		/* Find the end of the host name portion. */
 		for (cp2 = cp; *cp2 && *cp2 != ' ' && *cp2 != '\t'; cp2++)
 			;
@@ -273,8 +290,14 @@ check_host_in_hostfile_by_key_or_type(const char *filename,
 			continue;
 
 		/* Check if the current key is the same as the given key. */
-		if (key_equal(key, found)) {
-			/* Ok, they match. */
+		if (want_cert && key_equal(key->cert->signature_key, found)) {
+			/* Found CA cert for key */
+			debug3("check_host_in_hostfile: CA match line %d",
+			    linenum);
+			fclose(f);
+			return HOST_OK;
+		} else if (!want_cert && key_equal(key, found)) {
+			/* Found identical key */
 			debug3("check_host_in_hostfile: match line %d", linenum);
 			fclose(f);
 			return HOST_OK;