move check_host_cert() from sshconnect,c to sshkey.c and refactor

it to make it more generally usable and testable.

ok markus@

1 files changed, 20 insertions, 36 deletions

diff --git a/usr.bin/ssh/sshconnect.c b/usr.bin/ssh/sshconnect.c
index 65f2773870b..47904020d6b 100644
--- a/usr.bin/ssh/sshconnect.c
+++ b/usr.bin/ssh/sshconnect.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect.c,v 1.349 2020/12/22 00:15:23 djm Exp $ */
+/* $OpenBSD: sshconnect.c,v 1.350 2021/01/26 00:49:30 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -568,36 +568,6 @@ confirm(const char *prompt, const char *fingerprint)
 }
 
 static int
-check_host_cert(const char *host, const struct sshkey *key)
-{
-	const char *reason;
-	int r;
-
-	if (sshkey_cert_check_authority(key, 1, 0, host, &reason) != 0) {
-		error("%s", reason);
-		return 0;
-	}
-	if (sshbuf_len(key->cert->critical) != 0) {
-		error("Certificate for %s contains unsupported "
-		    "critical options(s)", host);
-		return 0;
-	}
-	if ((r = sshkey_check_cert_sigtype(key,
-	    options.ca_sign_algorithms)) != 0) {
-		logit_fr(r, "certificate signature algorithm %s",
-		    (key->cert == NULL || key->cert->signature_type == NULL) ?
-		    "(null)" : key->cert->signature_type);
-		return 0;
-	}
-	/* Do not attempt hostkey update if a certificate was successful */
-	if (options.update_hostkeys != 0) {
-		options.update_hostkeys = 0;
-		debug3_f("certificate host key in use; disabling UpdateHostkeys");
-	}
-	return 1;
-}
-
-static int
 sockaddr_is_local(struct sockaddr *hostaddr)
 {
 	switch (hostaddr->sa_family) {
@@ -925,7 +895,7 @@ check_host_key(char *hostname, const struct ssh_conn_info *cinfo,
 	char *ip = NULL, *host = NULL;
 	char hostline[1000], *hostp, *fp, *ra;
 	char msg[1024];
-	const char *type;
+	const char *type, *fail_reason;
 	const struct hostkey_entry *host_found = NULL, *ip_found = NULL;
 	int len, cancelled_forwarding = 0, confirmed;
 	int local = sockaddr_is_local(hostaddr);
@@ -1031,10 +1001,24 @@ check_host_key(char *hostname, const struct ssh_conn_info *cinfo,
 		    host, type, want_cert ? "certificate" : "key");
 		debug("Found %s in %s:%lu", want_cert ? "CA key" : "key",
 		    host_found->file, host_found->line);
-		if (want_cert &&
-		    !check_host_cert(options.host_key_alias == NULL ?
-		    hostname : options.host_key_alias, host_key))
-			goto fail;
+		if (want_cert) {
+			if (sshkey_cert_check_host(host_key,
+			    options.host_key_alias == NULL ?
+			    hostname : options.host_key_alias, 0,
+			    options.ca_sign_algorithms, &fail_reason) != 0) {
+				error("%s", fail_reason);
+				goto fail;
+			}
+			/*
+			 * Do not attempt hostkey update if a certificate was
+			 * successfully matched.
+			 */
+			if (options.update_hostkeys != 0) {
+				options.update_hostkeys = 0;
+				debug3_f("certificate host key in use; "
+				    "disabling UpdateHostkeys");
+			}
+		}
 		/* Turn off UpdateHostkeys if key was in system known_hosts */
 		if (options.update_hostkeys != 0 &&
 		    (path_in_hostfiles(host_found->file,