1 files changed, 119 insertions, 105 deletions

diff --git a/ssh-add.c b/ssh-add.c
index 0035cb84a0c1..2d5bec89cec5 100644
--- a/ssh-add.c
+++ b/ssh-add.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-add.c,v 1.173 2024/09/06 02:30:44 djm Exp $ */
+/* $OpenBSD: ssh-add.c,v 1.181 2025/09/29 03:17:54 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -54,6 +54,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <limits.h>
+#include <time.h>
 
 #include "xmalloc.h"
 #include "ssh.h"
@@ -70,6 +71,8 @@
 #include "sk-api.h"
 #include "hostfile.h"
 
+#define CERT_EXPIRY_GRACE	(5*60)
+
 /* argv0 */
 extern char *__progname;
 
@@ -84,10 +87,6 @@ static char *default_files[] = {
 #endif /* WITH_OPENSSL */
 	_PATH_SSH_CLIENT_ID_ED25519,
 	_PATH_SSH_CLIENT_ID_ED25519_SK,
-	_PATH_SSH_CLIENT_ID_XMSS,
-#ifdef WITH_DSA
-	_PATH_SSH_CLIENT_ID_DSA,
-#endif
 	NULL
 };
 
@@ -99,10 +98,6 @@ static int lifetime = 0;
 /* User has to confirm key use */
 static int confirm = 0;
 
-/* Maximum number of signatures (XMSS) */
-static u_int maxsign = 0;
-static u_int minleft = 0;
-
 /* we keep a cache of one passphrase */
 static char *pass = NULL;
 static void
@@ -243,19 +238,36 @@ delete_all(int agent_fd, int qflag)
 }
 
 static int
+check_cert_lifetime(const struct sshkey *cert, int cert_lifetime)
+{
+	time_t now;
+	uint64_t n;
+
+	if (cert == NULL || cert->cert == NULL || !sshkey_is_cert(cert) ||
+	    cert->cert->valid_before == 0xFFFFFFFFFFFFFFFFULL)
+		return cert_lifetime;
+	if ((now = time(NULL)) <= 0)
+		fatal_f("system time is at/before epoch");
+	if ((uint64_t)now > (cert->cert->valid_before + CERT_EXPIRY_GRACE))
+		return -1; /* certificate already expired */
+	n = (CERT_EXPIRY_GRACE + cert->cert->valid_before) - (uint64_t)now;
+	n = MINIMUM(n, INT_MAX);
+	if (cert_lifetime <= 0)
+		return (int)n;
+	return MINIMUM(cert_lifetime, (int)n);
+}
+
+static int
 add_file(int agent_fd, const char *filename, int key_only, int cert_only,
-    int qflag, const char *skprovider,
+    int qflag, int Nflag, const char *skprovider,
     struct dest_constraint **dest_constraints,
     size_t ndest_constraints)
 {
-	struct sshkey *private, *cert;
+	struct sshkey *private = NULL, *cert = NULL;
 	char *comment = NULL;
 	char msg[1024], *certpath = NULL;
-	int r, fd, ret = -1;
-	size_t i;
-	u_int32_t left;
+	int cert_lifetime, r, fd, ret = -1;
 	struct sshbuf *keyblob;
-	struct ssh_identitylist *idlist;
 
 	if (strcmp(filename, "-") == 0) {
 		fd = STDIN_FILENO;
@@ -331,38 +343,6 @@ add_file(int agent_fd, const char *filename, int key_only, int cert_only,
 		comment = xstrdup(filename);
 	sshbuf_free(keyblob);
 
-	/* For XMSS */
-	if ((r = sshkey_set_filename(private, filename)) != 0) {
-		fprintf(stderr, "Could not add filename to private key: %s (%s)\n",
-		    filename, comment);
-		goto out;
-	}
-	if (maxsign && minleft &&
-	    (r = ssh_fetch_identitylist(agent_fd, &idlist)) == 0) {
-		for (i = 0; i < idlist->nkeys; i++) {
-			if (!sshkey_equal_public(idlist->keys[i], private))
-				continue;
-			left = sshkey_signatures_left(idlist->keys[i]);
-			if (left < minleft) {
-				fprintf(stderr,
-				    "Only %d signatures left.\n", left);
-				break;
-			}
-			fprintf(stderr, "Skipping update: ");
-			if (left == minleft) {
-				fprintf(stderr,
-				    "required signatures left (%d).\n", left);
-			} else {
-				fprintf(stderr,
-				    "more signatures left (%d) than"
-				    " required (%d).\n", left, minleft);
-			}
-			ssh_free_identitylist(idlist);
-			goto out;
-		}
-		ssh_free_identitylist(idlist);
-	}
-
 	if (sshkey_is_sk(private)) {
 		if (skprovider == NULL) {
 			fprintf(stderr, "Cannot load FIDO key %s "
@@ -374,26 +354,27 @@ add_file(int agent_fd, const char *filename, int key_only, int cert_only,
 		skprovider = NULL;
 	}
 
-	if (!cert_only &&
-	    (r = ssh_add_identity_constrained(agent_fd, private, comment,
-	    lifetime, confirm, maxsign, skprovider,
-	    dest_constraints, ndest_constraints)) == 0) {
-		ret = 0;
-		if (!qflag) {
-			fprintf(stderr, "Identity added: %s (%s)\n",
-			    filename, comment);
-			if (lifetime != 0) {
-				fprintf(stderr,
-				    "Lifetime set to %d seconds\n", lifetime);
-			}
-			if (confirm != 0) {
-				fprintf(stderr, "The user must confirm "
-				    "each use of the key\n");
+	if (!cert_only) {
+		if ((r = ssh_add_identity_constrained(agent_fd, private,
+		    comment, lifetime, confirm, skprovider,
+		    dest_constraints, ndest_constraints)) == 0) {
+			ret = 0;
+			if (!qflag) {
+				fprintf(stderr, "Identity added: %s (%s)\n",
+				    filename, comment);
+				if (lifetime != 0) {
+					fprintf(stderr, "Lifetime set to %s\n",
+					    fmt_timeframe((time_t)lifetime));
+				}
+				if (confirm != 0) {
+					fprintf(stderr, "The user must confirm "
+					    "each use of the key\n");
+				}
 			}
+		} else {
+			fprintf(stderr, "Could not add identity \"%s\": %s\n",
+			    filename, ssh_err(r));
 		}
-	} else {
-		fprintf(stderr, "Could not add identity \"%s\": %s\n",
-		    filename, ssh_err(r));
 	}
 
 	/* Skip trying to load the cert if requested */
@@ -412,25 +393,28 @@ add_file(int agent_fd, const char *filename, int key_only, int cert_only,
 	if (!sshkey_equal_public(cert, private)) {
 		error("Certificate %s does not match private key %s",
 		    certpath, filename);
-		sshkey_free(cert);
+		goto out;
+	}
+
+	cert_lifetime = lifetime;
+	if (!Nflag &&
+	    (cert_lifetime = check_cert_lifetime(cert, cert_lifetime)) == -1) {
+		logit("Certificate %s has already expired; ignored", certpath);
 		goto out;
 	}
 
 	/* Graft with private bits */
 	if ((r = sshkey_to_certified(private)) != 0) {
 		error_fr(r, "sshkey_to_certified");
-		sshkey_free(cert);
 		goto out;
 	}
 	if ((r = sshkey_cert_copy(cert, private)) != 0) {
 		error_fr(r, "sshkey_cert_copy");
-		sshkey_free(cert);
 		goto out;
 	}
-	sshkey_free(cert);
-
+	/* send to agent */
 	if ((r = ssh_add_identity_constrained(agent_fd, private, comment,
-	    lifetime, confirm, maxsign, skprovider,
+	    cert_lifetime, confirm, skprovider,
 	    dest_constraints, ndest_constraints)) != 0) {
 		error_r(r, "Certificate %s (%s) add failed", certpath,
 		    private->cert->key_id);
@@ -440,9 +424,9 @@ add_file(int agent_fd, const char *filename, int key_only, int cert_only,
 	if (!qflag) {
 		fprintf(stderr, "Certificate added: %s (%s)\n", certpath,
 		    private->cert->key_id);
-		if (lifetime != 0) {
-			fprintf(stderr, "Lifetime set to %d seconds\n",
-			    lifetime);
+		if (cert_lifetime != 0) {
+			fprintf(stderr, "Lifetime set to %s\n",
+			    fmt_timeframe((time_t)cert_lifetime));
 		}
 		if (confirm != 0) {
 			fprintf(stderr, "The user must confirm each use "
@@ -453,6 +437,7 @@ add_file(int agent_fd, const char *filename, int key_only, int cert_only,
  out:
 	free(certpath);
 	free(comment);
+	sshkey_free(cert);
 	sshkey_free(private);
 
 	return ret;
@@ -534,7 +519,6 @@ list_identities(int agent_fd, int do_fp)
 	char *fp;
 	int r;
 	struct ssh_identitylist *idlist;
-	u_int32_t left;
 	size_t i;
 
 	if ((r = ssh_fetch_identitylist(agent_fd, &idlist)) != 0) {
@@ -559,12 +543,7 @@ list_identities(int agent_fd, int do_fp)
 				    ssh_err(r));
 				continue;
 			}
-			fprintf(stdout, " %s", idlist->comments[i]);
-			left = sshkey_signatures_left(idlist->keys[i]);
-			if (left > 0)
-				fprintf(stdout,
-				    " [signatures left %d]", left);
-			fprintf(stdout, "\n");
+			fprintf(stdout, " %s\n", idlist->comments[i]);
 		}
 	}
 	ssh_free_identitylist(idlist);
@@ -623,7 +602,7 @@ load_resident_keys(int agent_fd, const char *skprovider, int qflag,
 		    fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
 			fatal_f("sshkey_fingerprint failed");
 		if ((r = ssh_add_identity_constrained(agent_fd, key, "",
-		    lifetime, confirm, maxsign, skprovider,
+		    lifetime, confirm, skprovider,
 		    dest_constraints, ndest_constraints)) != 0) {
 			error("Unable to add key %s %s",
 			    sshkey_type(key), fp);
@@ -655,7 +634,7 @@ load_resident_keys(int agent_fd, const char *skprovider, int qflag,
 
 static int
 do_file(int agent_fd, int deleting, int key_only, int cert_only,
-    char *file, int qflag, const char *skprovider,
+    char *file, int qflag, int Nflag, const char *skprovider,
     struct dest_constraint **dest_constraints, size_t ndest_constraints)
 {
 	if (deleting) {
@@ -663,7 +642,7 @@ do_file(int agent_fd, int deleting, int key_only, int cert_only,
 		    cert_only, qflag) == -1)
 			return -1;
 	} else {
-		if (add_file(agent_fd, file, key_only, cert_only, qflag,
+		if (add_file(agent_fd, file, key_only, cert_only, qflag, Nflag,
 		    skprovider, dest_constraints, ndest_constraints) == -1)
 			return -1;
 	}
@@ -687,6 +666,47 @@ stringlist_append(char ***listp, const char *s)
 }
 
 static void
+stringlist_free(char **list)
+{
+	size_t i = 0;
+
+	if (list == NULL)
+		return;
+	for (i = 0; list[i] != NULL; i++)
+		free(list[i]);
+	free(list);
+}
+
+static void
+free_dest_constraint_hop(struct dest_constraint_hop *dch)
+{
+	u_int i;
+
+	if (dch == NULL)
+		return;
+	free(dch->user);
+	free(dch->hostname);
+	for (i = 0; i < dch->nkeys; i++)
+		sshkey_free(dch->keys[i]);
+	free(dch->keys);
+	free(dch->key_is_ca);
+}
+
+static void
+free_dest_constraints(struct dest_constraint **dcs, size_t ndcs)
+{
+	size_t i;
+
+	for (i = 0; i < ndcs; i++) {
+		free_dest_constraint_hop(&dcs[i]->from);
+		free_dest_constraint_hop(&dcs[i]->to);
+		free(dcs[i]);
+	}
+	free(dcs);
+}
+
+
+static void
 parse_dest_constraint_hop(const char *s, struct dest_constraint_hop *dch,
     char **hostkey_files)
 {
@@ -794,9 +814,6 @@ usage(void)
 	fprintf(stderr,
 "usage: ssh-add [-CcDdKkLlqvXx] [-E fingerprint_hash] [-H hostkey_file]\n"
 "               [-h destination_constraint] [-S provider] [-t life]\n"
-#ifdef WITH_XMSS
-"               [-M maxsign] [-m minleft]\n"
-#endif
 "               [file ...]\n"
 "       ssh-add -s pkcs11 [-Cv] [certificate ...]\n"
 "       ssh-add -e pkcs11\n"
@@ -814,12 +831,12 @@ main(int argc, char **argv)
 	char **dest_constraint_strings = NULL, **hostkey_files = NULL;
 	int r, i, ch, deleting = 0, ret = 0, key_only = 0, cert_only = 0;
 	int do_download = 0, xflag = 0, lflag = 0, Dflag = 0;
-	int qflag = 0, Tflag = 0;
+	int qflag = 0, Tflag = 0, Nflag = 0;
 	SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
 	LogLevel log_level = SYSLOG_LEVEL_INFO;
 	struct sshkey *k, **certs = NULL;
 	struct dest_constraint **dest_constraints = NULL;
-	size_t ndest_constraints = 0, ncerts = 0;
+	size_t n, ndest_constraints = 0, ncerts = 0;
 
 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();
@@ -846,7 +863,7 @@ main(int argc, char **argv)
 
 	skprovider = getenv("SSH_SK_PROVIDER");
 
-	while ((ch = getopt(argc, argv, "vkKlLCcdDTxXE:e:h:H:M:m:qs:S:t:")) != -1) {
+	while ((ch = getopt(argc, argv, "vkKlLNCcdDTxXE:e:h:H:M:m:qs:S:t:")) != -1) {
 		switch (ch) {
 		case 'v':
 			if (log_level == SYSLOG_LEVEL_INFO)
@@ -854,6 +871,9 @@ main(int argc, char **argv)
 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
 				log_level++;
 			break;
+		case 'N':
+			Nflag = 1;
+			break;
 		case 'E':
 			fingerprint_hash = ssh_digest_alg_by_name(optarg);
 			if (fingerprint_hash == -1)
@@ -890,20 +910,8 @@ main(int argc, char **argv)
 			confirm = 1;
 			break;
 		case 'm':
-			minleft = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
-			if (minleft == 0) {
-				usage();
-				ret = 1;
-				goto done;
-			}
-			break;
 		case 'M':
-			maxsign = (u_int)strtonum(optarg, 1, UINT_MAX, NULL);
-			if (maxsign == 0) {
-				usage();
-				ret = 1;
-				goto done;
-			}
+			/* deprecated */
 			break;
 		case 'd':
 			deleting = 1;
@@ -1003,6 +1011,9 @@ main(int argc, char **argv)
 		    dest_constraints, ndest_constraints,
 		    certs, ncerts) == -1)
 			ret = 1;
+		for (n = 0; n < ncerts; n++)
+			sshkey_free(certs[n]);
+		free(certs);
 		goto done;
 	}
 	if (do_download) {
@@ -1032,7 +1043,7 @@ main(int argc, char **argv)
 			if (stat(buf, &st) == -1)
 				continue;
 			if (do_file(agent_fd, deleting, key_only, cert_only,
-			    buf, qflag, skprovider,
+			    buf, qflag, Nflag, skprovider,
 			    dest_constraints, ndest_constraints) == -1)
 				ret = 1;
 			else
@@ -1043,13 +1054,16 @@ main(int argc, char **argv)
 	} else {
 		for (i = 0; i < argc; i++) {
 			if (do_file(agent_fd, deleting, key_only, cert_only,
-			    argv[i], qflag, skprovider,
+			    argv[i], qflag, Nflag, skprovider,
 			    dest_constraints, ndest_constraints) == -1)
 				ret = 1;
 		}
 	}
 done:
 	clear_pass();
+	stringlist_free(hostkey_files);
+	stringlist_free(dest_constraint_strings);
+	free_dest_constraints(dest_constraints, ndest_constraints);
 	ssh_close_authentication_socket(agent_fd);
 	return ret;
 }