===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh-keygen.c,v
retrieving revision 1.288
retrieving revision 1.332
diff -u -r1.288 -r1.332
--- src/usr.bin/ssh/ssh-keygen.c	2016/02/15 09:47:49	1.288
+++ src/usr.bin/ssh/ssh-keygen.c	2019/06/21 04:21:04	1.332
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.288 2016/02/15 09:47:49 dtucker Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.332 2019/06/21 04:21:04 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -28,10 +28,10 @@
 #include <string.h>
 #include <unistd.h>
 #include <limits.h>
+#include <locale.h>
 
 #include "xmalloc.h"
 #include "sshkey.h"
-#include "rsa.h"
 #include "authfile.h"
 #include "uuencode.h"
 #include "sshbuf.h"
@@ -47,6 +47,8 @@
 #include "atomicio.h"
 #include "krl.h"
 #include "digest.h"
+#include "utf8.h"
+#include "authfd.h"
 
 #ifdef ENABLE_PKCS11
 #include "ssh-pkcs11.h"
@@ -58,76 +60,52 @@
 # define DEFAULT_KEY_TYPE_NAME "ed25519"
 #endif
 
-/* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
-#define DEFAULT_BITS		2048
+/*
+ * Default number of bits in the RSA, DSA and ECDSA keys.  These value can be
+ * overridden on the command line.
+ *
+ * These values, with the exception of DSA, provide security equivalent to at
+ * least 128 bits of security according to NIST Special Publication 800-57:
+ * Recommendation for Key Management Part 1 rev 4 section 5.6.1.
+ * For DSA it (and FIPS-186-4 section 4.2) specifies that the only size for
+ * which a 160bit hash is acceptable is 1kbit, and since ssh-dss specifies only
+ * SHA1 we limit the DSA key size 1k bits.
+ */
+#define DEFAULT_BITS		3072
 #define DEFAULT_BITS_DSA	1024
 #define DEFAULT_BITS_ECDSA	256
-u_int32_t bits = 0;
 
-/*
- * Flag indicating that we just want to change the passphrase.  This can be
- * set on the command line.
- */
-int change_passphrase = 0;
+static int quiet = 0;
 
-/*
- * Flag indicating that we just want to change the comment.  This can be set
- * on the command line.
- */
-int change_comment = 0;
-
-int quiet = 0;
-
-int log_level = SYSLOG_LEVEL_INFO;
-
-/* Flag indicating that we want to hash a known_hosts file */
-int hash_hosts = 0;
-/* Flag indicating that we want lookup a host in known_hosts file */
-int find_host = 0;
-/* Flag indicating that we want to delete a host from a known_hosts file */
-int delete_host = 0;
-
-/* Flag indicating that we want to show the contents of a certificate */
-int show_cert = 0;
-
 /* Flag indicating that we just want to see the key fingerprint */
-int print_fingerprint = 0;
-int print_bubblebabble = 0;
+static int print_fingerprint = 0;
+static int print_bubblebabble = 0;
 
 /* Hash algorithm to use for fingerprints. */
-int fingerprint_hash = SSH_FP_HASH_DEFAULT;
+static int fingerprint_hash = SSH_FP_HASH_DEFAULT;
 
 /* The identity file name, given on the command line or entered by the user. */
-char identity_file[1024];
-int have_identity = 0;
+static char identity_file[1024];
+static int have_identity = 0;
 
 /* This is set to the passphrase if given on the command line. */
-char *identity_passphrase = NULL;
+static char *identity_passphrase = NULL;
 
 /* This is set to the new passphrase if given on the command line. */
-char *identity_new_passphrase = NULL;
+static char *identity_new_passphrase = NULL;
 
-/* This is set to the new comment if given on the command line. */
-char *identity_comment = NULL;
-
-/* Path to CA key when certifying keys. */
-char *ca_key_path = NULL;
-
-/* Certificate serial number */
-unsigned long long cert_serial = 0;
-
 /* Key type when certifying */
-u_int cert_key_type = SSH2_CERT_TYPE_USER;
+static u_int cert_key_type = SSH2_CERT_TYPE_USER;
 
 /* "key ID" of signed key */
-char *cert_key_id = NULL;
+static char *cert_key_id = NULL;
 
 /* Comma-separated list of principal names for certifying keys */
-char *cert_principals = NULL;
+static char *cert_principals = NULL;
 
 /* Validity period for certificates */
-u_int64_t cert_valid_from = 0;
-u_int64_t cert_valid_to = ~0ULL;
+static u_int64_t cert_valid_from = 0;
+static u_int64_t cert_valid_to = ~0ULL;
 
 /* Certificate options */
 #define CERTOPT_X_FWD	(1)
@@ -137,42 +115,47 @@
 #define CERTOPT_USER_RC	(1<<4)
 #define CERTOPT_DEFAULT	(CERTOPT_X_FWD|CERTOPT_AGENT_FWD| \
 			 CERTOPT_PORT_FWD|CERTOPT_PTY|CERTOPT_USER_RC)
-u_int32_t certflags_flags = CERTOPT_DEFAULT;
-char *certflags_command = NULL;
-char *certflags_src_addr = NULL;
+static u_int32_t certflags_flags = CERTOPT_DEFAULT;
+static char *certflags_command = NULL;
+static char *certflags_src_addr = NULL;
 
+/* Arbitrary extensions specified by user */
+struct cert_userext {
+	char *key;
+	char *val;
+	int crit;
+};
+static struct cert_userext *cert_userext;
+static size_t ncert_userext;
+
 /* Conversion to/from various formats */
-int convert_to = 0;
-int convert_from = 0;
 enum {
 	FMT_RFC4716,
 	FMT_PKCS8,
 	FMT_PEM
 } convert_format = FMT_RFC4716;
-int print_public = 0;
-int print_generic = 0;
 
-char *key_type_name = NULL;
+static char *key_type_name = NULL;
 
 /* Load key from this PKCS#11 provider */
-char *pkcs11provider = NULL;
+static char *pkcs11provider = NULL;
 
 /* Use new OpenSSH private key format when writing SSH2 keys instead of PEM */
-int use_new_format = 0;
+static int use_new_format = 1;
 
 /* Cipher for new-format private keys */
-char *new_format_cipher = NULL;
+static char *new_format_cipher = NULL;
 
 /*
  * Number of KDF rounds to derive new format keys /
  * number of primality trials when screening moduli.
  */
-int rounds = 0;
+static int rounds = 0;
 
 /* argv0 */
 extern char *__progname;
 
-char hostname[NI_MAXHOST];
+static char hostname[NI_MAXHOST];
 
 #ifdef WITH_OPENSSL
 /* moduli.c */
@@ -200,8 +183,7 @@
 				*bitsp = sshkey_curve_nid_to_bits(nid);
 			if (*bitsp == 0)
 				*bitsp = DEFAULT_BITS_ECDSA;
-		}
-		else
+		} else
 #endif
 			*bitsp = DEFAULT_BITS;
 	}
@@ -210,13 +192,21 @@
 	    OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
 	if (*bitsp > maxbits)
 		fatal("key bits exceeds maximum %d", maxbits);
-	if (type == KEY_DSA && *bitsp != 1024)
-		fatal("DSA keys must be 1024 bits");
-	else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 1024)
-		fatal("Key must at least be 1024 bits");
-	else if (type == KEY_ECDSA && sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
-		fatal("Invalid ECDSA key length - valid lengths are "
-		    "256, 384 or 521 bits");
+	switch (type) {
+	case KEY_DSA:
+		if (*bitsp != 1024)
+			fatal("Invalid DSA key length: must be 1024 bits");
+		break;
+	case KEY_RSA:
+		if (*bitsp < SSH_RSA_MINIMUM_MODULUS_SIZE)
+			fatal("Invalid RSA key length: minimum is %d bits",
+			    SSH_RSA_MINIMUM_MODULUS_SIZE);
+		break;
+	case KEY_ECDSA:
+		if (sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
+			fatal("Invalid ECDSA key length: valid lengths are "
+			    "256, 384 or 521 bits");
+	}
 #endif
 }
 
@@ -230,9 +220,6 @@
 		name = _PATH_SSH_CLIENT_ID_RSA;
 	else {
 		switch (sshkey_type_from_name(key_type_name)) {
-		case KEY_RSA1:
-			name = _PATH_SSH_CLIENT_IDENTITY;
-			break;
 		case KEY_DSA_CERT:
 		case KEY_DSA:
 			name = _PATH_SSH_CLIENT_ID_DSA;
@@ -249,6 +236,10 @@
 		case KEY_ED25519_CERT:
 			name = _PATH_SSH_CLIENT_ID_ED25519;
 			break;
+		case KEY_XMSS:
+		case KEY_XMSS_CERT:
+			name = _PATH_SSH_CLIENT_ID_XMSS;
+			break;
 		default:
 			fatal("bad key type");
 		}
@@ -302,8 +293,6 @@
 	char comment[61];
 	int r;
 
-	if (k->type == KEY_RSA1)
-		fatal("version 1 keys are not supported");
 	if ((r = sshkey_to_blob(k, &blob, &len)) != 0)
 		fatal("key_to_blob failed: %s", ssh_err(r));
 	/* Comment + surrounds must fit into 72 chars (RFC 4716 sec 3.3) */
@@ -325,7 +314,6 @@
 do_convert_to_pkcs8(struct sshkey *k)
 {
 	switch (sshkey_type_plain(k->type)) {
-	case KEY_RSA1:
 	case KEY_RSA:
 		if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
 			fatal("PEM_write_RSA_PUBKEY failed");
@@ -348,18 +336,10 @@
 do_convert_to_pem(struct sshkey *k)
 {
 	switch (sshkey_type_plain(k->type)) {
-	case KEY_RSA1:
 	case KEY_RSA:
 		if (!PEM_write_RSAPublicKey(stdout, k->rsa))
 			fatal("PEM_write_RSAPublicKey failed");
 		break;
-#if notyet /* OpenSSH 0.9.8 lacks this function */
-	case KEY_DSA:
-		if (!PEM_write_DSAPublicKey(stdout, k->dsa))
-			fatal("PEM_write_DSAPublicKey failed");
-		break;
-#endif
-	/* XXX ECDSA? */
 	default:
 		fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
 	}
@@ -428,7 +408,10 @@
 	u_int magic, i1, i2, i3, i4;
 	size_t slen;
 	u_long e;
-
+	BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL;
+	BIGNUM *dsa_pub_key = NULL, *dsa_priv_key = NULL;
+	BIGNUM *rsa_n = NULL, *rsa_e = NULL, *rsa_d = NULL;
+	BIGNUM *rsa_p = NULL, *rsa_q = NULL, *rsa_iqmp = NULL;
 	if ((b = sshbuf_from(blob, blen)) == NULL)
 		fatal("%s: sshbuf_from failed", __func__);
 	if ((r = sshbuf_get_u32(b, &magic)) != 0)
@@ -466,17 +449,29 @@
 		free(type);
 		return NULL;
 	}
-	if ((key = sshkey_new_private(ktype)) == NULL)
-		fatal("key_new_private failed");
+	if ((key = sshkey_new(ktype)) == NULL)
+		fatal("sshkey_new failed");
 	free(type);
 
 	switch (key->type) {
 	case KEY_DSA:
-		buffer_get_bignum_bits(b, key->dsa->p);
-		buffer_get_bignum_bits(b, key->dsa->g);
-		buffer_get_bignum_bits(b, key->dsa->q);
-		buffer_get_bignum_bits(b, key->dsa->pub_key);
-		buffer_get_bignum_bits(b, key->dsa->priv_key);
+		if ((dsa_p = BN_new()) == NULL ||
+		    (dsa_q = BN_new()) == NULL ||
+		    (dsa_g = BN_new()) == NULL ||
+		    (dsa_pub_key = BN_new()) == NULL ||
+		    (dsa_priv_key = BN_new()) == NULL)
+			fatal("%s: BN_new", __func__);
+		buffer_get_bignum_bits(b, dsa_p);
+		buffer_get_bignum_bits(b, dsa_g);
+		buffer_get_bignum_bits(b, dsa_q);
+		buffer_get_bignum_bits(b, dsa_pub_key);
+		buffer_get_bignum_bits(b, dsa_priv_key);
+		if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g))
+			fatal("%s: DSA_set0_pqg failed", __func__);
+		dsa_p = dsa_q = dsa_g = NULL; /* transferred */
+		if (!DSA_set0_key(key->dsa, dsa_pub_key, dsa_priv_key))
+			fatal("%s: DSA_set0_key failed", __func__);
+		dsa_pub_key = dsa_priv_key = NULL; /* transferred */
 		break;
 	case KEY_RSA:
 		if ((r = sshbuf_get_u8(b, &e1)) != 0 ||
@@ -493,18 +488,34 @@
 			e += e3;
 			debug("e %lx", e);
 		}
-		if (!BN_set_word(key->rsa->e, e)) {
+		if ((rsa_e = BN_new()) == NULL)
+			fatal("%s: BN_new", __func__);
+		if (!BN_set_word(rsa_e, e)) {
+			BN_clear_free(rsa_e);
 			sshbuf_free(b);
 			sshkey_free(key);
 			return NULL;
 		}
-		buffer_get_bignum_bits(b, key->rsa->d);
-		buffer_get_bignum_bits(b, key->rsa->n);
-		buffer_get_bignum_bits(b, key->rsa->iqmp);
-		buffer_get_bignum_bits(b, key->rsa->q);
-		buffer_get_bignum_bits(b, key->rsa->p);
-		if ((r = rsa_generate_additional_parameters(key->rsa)) != 0)
+		if ((rsa_n = BN_new()) == NULL ||
+		    (rsa_d = BN_new()) == NULL ||
+		    (rsa_p = BN_new()) == NULL ||
+		    (rsa_q = BN_new()) == NULL ||
+		    (rsa_iqmp = BN_new()) == NULL)
+			fatal("%s: BN_new", __func__);
+		buffer_get_bignum_bits(b, rsa_d);
+		buffer_get_bignum_bits(b, rsa_n);
+		buffer_get_bignum_bits(b, rsa_iqmp);
+		buffer_get_bignum_bits(b, rsa_q);
+		buffer_get_bignum_bits(b, rsa_p);
+		if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, rsa_d))
+			fatal("%s: RSA_set0_key failed", __func__);
+		rsa_n = rsa_e = rsa_d = NULL; /* transferred */
+		if (!RSA_set0_factors(key->rsa, rsa_p, rsa_q))
+			fatal("%s: RSA_set0_factors failed", __func__);
+		rsa_p = rsa_q = NULL; /* transferred */
+		if ((r = ssh_rsa_complete_crt_parameters(key, rsa_iqmp)) != 0)
 			fatal("generate RSA parameters failed: %s", ssh_err(r));
+		BN_clear_free(rsa_iqmp);
 		break;
 	}
 	rlen = sshbuf_len(b);
@@ -515,7 +526,7 @@
 
 	/* try the key */
 	if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 ||
-	    sshkey_verify(key, sig, slen, data, sizeof(data), 0) != 0) {
+	    sshkey_verify(key, sig, slen, data, sizeof(data), NULL, 0) != 0) {
 		sshkey_free(key);
 		free(sig);
 		return NULL;
@@ -612,7 +623,7 @@
 		    identity_file);
 	}
 	fclose(fp);
-	switch (EVP_PKEY_type(pubkey->type)) {
+	switch (EVP_PKEY_base_id(pubkey)) {
 	case EVP_PKEY_RSA:
 		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
 			fatal("sshkey_new failed");
@@ -634,7 +645,7 @@
 		break;
 	default:
 		fatal("%s: unsupported pubkey type %d", __func__,
-		    EVP_PKEY_type(pubkey->type));
+		    EVP_PKEY_base_id(pubkey));
 	}
 	EVP_PKEY_free(pubkey);
 	return;
@@ -645,9 +656,6 @@
 {
 	FILE *fp;
 	RSA *rsa;
-#ifdef notyet
-	DSA *dsa;
-#endif
 
 	if ((fp = fopen(identity_file, "r")) == NULL)
 		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
@@ -659,18 +667,6 @@
 		fclose(fp);
 		return;
 	}
-#if notyet /* OpenSSH 0.9.8 lacks this function */
-	rewind(fp);
-	if ((dsa = PEM_read_DSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
-		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
-			fatal("sshkey_new failed");
-		(*k)->type = KEY_DSA;
-		(*k)->dsa = dsa;
-		fclose(fp);
-		return;
-	}
-	/* XXX ECDSA */
-#endif
 	fatal("%s: unrecognised raw private key format", __func__);
 }
 
@@ -745,7 +741,7 @@
 		fatal("%s: %s", identity_file, strerror(errno));
 	prv = load_identity(identity_file);
 	if ((r = sshkey_write(prv, stdout)) != 0)
-		error("key_write failed: %s", ssh_err(r));
+		error("sshkey_write failed: %s", ssh_err(r));
 	sshkey_free(prv);
 	fprintf(stdout, "\n");
 	exit(0);
@@ -764,7 +760,7 @@
 	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
 
-	pkcs11_init(0);
+	pkcs11_init(1);
 	nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys);
 	if (nkeys <= 0)
 		fatal("cannot read public key from pkcs11");
@@ -777,7 +773,7 @@
 				fatal("%s: sshkey_fingerprint fail", __func__);
 			printf("%u %s %s (PKCS11 key)\n", sshkey_size(keys[i]),
 			    fp, sshkey_type(keys[i]));
-			if (log_level >= SYSLOG_LEVEL_VERBOSE)
+			if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
 				printf("%s\n", ra);
 			free(ra);
 			free(fp);
@@ -801,13 +797,6 @@
 	struct sshkey *ret;
 	int r;
 
-	if ((ret = sshkey_new(KEY_RSA1)) == NULL)
-		fatal("sshkey_new failed");
-	/* Try RSA1 */
-	if ((r = sshkey_read(ret, cpp)) == 0)
-		return ret;
-	/* Try modern */
-	sshkey_free(ret);
 	if ((ret = sshkey_new(KEY_UNSPEC)) == NULL)
 		fatal("sshkey_new failed");
 	if ((r = sshkey_read(ret, cpp)) == 0)
@@ -830,9 +819,9 @@
 	ra = sshkey_fingerprint(public, fingerprint_hash, SSH_FP_RANDOMART);
 	if (fp == NULL || ra == NULL)
 		fatal("%s: sshkey_fingerprint failed", __func__);
-	printf("%u %s %s (%s)\n", sshkey_size(public), fp,
+	mprintf("%u %s %s (%s)\n", sshkey_size(public), fp,
 	    comment ? comment : "no comment", sshkey_type(public));
-	if (log_level >= SYSLOG_LEVEL_VERBOSE)
+	if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
 		printf("%s\n", ra);
 	free(ra);
 	free(fp);
@@ -867,10 +856,11 @@
 {
 	FILE *f;
 	struct sshkey *public = NULL;
-	char *comment = NULL, *cp, *ep, line[SSH_MAX_PUBKEY_BYTES];
+	char *comment = NULL, *cp, *ep, *line = NULL;
+	size_t linesize = 0;
 	int i, invalid = 1;
 	const char *path;
-	long int lnum = 0;
+	u_long lnum = 0;
 
 	if (!have_identity)
 		ask_filename(pw, "Enter file in which the key is");
@@ -882,7 +872,8 @@
 	} else if ((f = fopen(path, "r")) == NULL)
 		fatal("%s: %s: %s", __progname, path, strerror(errno));
 
-	while (read_keyfile_line(f, path, line, sizeof(line), &lnum) == 0) {
+	while (getline(&line, &linesize, f) != -1) {
+		lnum++;
 		cp = line;
 		cp[strcspn(cp, "\n")] = '\0';
 		/* Trim leading space and comments */
@@ -902,6 +893,7 @@
 		 */
 		if (lnum == 1 && strcmp(identity_file, "-") != 0 &&
 		    strstr(cp, "PRIVATE KEY") != NULL) {
+			free(line);
 			fclose(f);
 			fingerprint_private(path);
 			exit(0);
@@ -933,7 +925,7 @@
 		}
 		/* Retry after parsing leading hostname/key options */
 		if (public == NULL && (public = try_read_key(&cp)) == NULL) {
-			debug("%s:%ld: not a public key", path, lnum);
+			debug("%s:%lu: not a public key", path, lnum);
 			continue;
 		}
 
@@ -948,6 +940,7 @@
 		invalid = 0; /* One good key in the file is sufficient */
 	}
 	fclose(f);
+	free(line);
 
 	if (invalid)
 		fatal("%s is not a public key file.", path);
@@ -963,34 +956,53 @@
 		char *path;
 	} key_types[] = {
 #ifdef WITH_OPENSSL
-#ifdef WITH_SSH1
-		{ "rsa1", "RSA1", _PATH_HOST_KEY_FILE },
-#endif /* WITH_SSH1 */
 		{ "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
 		{ "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
 		{ "ecdsa", "ECDSA",_PATH_HOST_ECDSA_KEY_FILE },
 #endif /* WITH_OPENSSL */
 		{ "ed25519", "ED25519",_PATH_HOST_ED25519_KEY_FILE },
+#ifdef WITH_XMSS
+		{ "xmss", "XMSS",_PATH_HOST_XMSS_KEY_FILE },
+#endif /* WITH_XMSS */
 		{ NULL, NULL, NULL }
 	};
 
+	u_int bits = 0;
 	int first = 0;
 	struct stat st;
 	struct sshkey *private, *public;
-	char comment[1024];
+	char comment[1024], *prv_tmp, *pub_tmp, *prv_file, *pub_file;
 	int i, type, fd, r;
 	FILE *f;
 
 	for (i = 0; key_types[i].key_type; i++) {
-		if (stat(key_types[i].path, &st) == 0)
-			continue;
-		if (errno != ENOENT) {
+		public = private = NULL;
+		prv_tmp = pub_tmp = prv_file = pub_file = NULL;
+
+		xasprintf(&prv_file, "%s%s",
+		    identity_file, key_types[i].path);
+
+		/* Check whether private key exists and is not zero-length */
+		if (stat(prv_file, &st) == 0) {
+			if (st.st_size != 0)
+				goto next;
+		} else if (errno != ENOENT) {
 			error("Could not stat %s: %s", key_types[i].path,
 			    strerror(errno));
-			first = 0;
-			continue;
+			goto failnext;
 		}
 
+		/*
+		 * Private key doesn't exist or is invalid; proceed with
+		 * key generation.
+		 */
+		xasprintf(&prv_tmp, "%s%s.XXXXXXXXXX",
+		    identity_file, key_types[i].path);
+		xasprintf(&pub_tmp, "%s%s.pub.XXXXXXXXXX",
+		    identity_file, key_types[i].path);
+		xasprintf(&pub_file, "%s%s.pub",
+		    identity_file, key_types[i].path);
+
 		if (first == 0) {
 			first = 1;
 			printf("%s: generating new host keys: ", __progname);
@@ -998,56 +1010,76 @@
 		printf("%s ", key_types[i].key_type_display);
 		fflush(stdout);
 		type = sshkey_type_from_name(key_types[i].key_type);
-		strlcpy(identity_file, key_types[i].path, sizeof(identity_file));
+		if ((fd = mkstemp(prv_tmp)) == -1) {
+			error("Could not save your public key in %s: %s",
+			    prv_tmp, strerror(errno));
+			goto failnext;
+		}
+		close(fd); /* just using mkstemp() to generate/reserve a name */
 		bits = 0;
 		type_bits_valid(type, NULL, &bits);
 		if ((r = sshkey_generate(type, bits, &private)) != 0) {
-			error("key_generate failed: %s", ssh_err(r));
-			first = 0;
-			continue;
+			error("sshkey_generate failed: %s", ssh_err(r));
+			goto failnext;
 		}
 		if ((r = sshkey_from_private(private, &public)) != 0)
 			fatal("sshkey_from_private failed: %s", ssh_err(r));
 		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name,
 		    hostname);
-		if ((r = sshkey_save_private(private, identity_file, "",
+		if ((r = sshkey_save_private(private, prv_tmp, "",
 		    comment, use_new_format, new_format_cipher, rounds)) != 0) {
 			error("Saving key \"%s\" failed: %s",
-			    identity_file, ssh_err(r));
-			sshkey_free(private);
-			sshkey_free(public);
-			first = 0;
-			continue;
+			    prv_tmp, ssh_err(r));
+			goto failnext;
 		}
-		sshkey_free(private);
-		strlcat(identity_file, ".pub", sizeof(identity_file));
-		fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-		if (fd == -1) {
-			error("Could not save your public key in %s",
-			    identity_file);
-			sshkey_free(public);
-			first = 0;
-			continue;
+		if ((fd = mkstemp(pub_tmp)) == -1) {
+			error("Could not save your public key in %s: %s",
+			    pub_tmp, strerror(errno));
+			goto failnext;
 		}
+		(void)fchmod(fd, 0644);
 		f = fdopen(fd, "w");
 		if (f == NULL) {
-			error("fdopen %s failed", identity_file);
+			error("fdopen %s failed: %s", pub_tmp, strerror(errno));
 			close(fd);
-			sshkey_free(public);
-			first = 0;
-			continue;
+			goto failnext;
 		}
 		if ((r = sshkey_write(public, f)) != 0) {
 			error("write key failed: %s", ssh_err(r));
 			fclose(f);
-			sshkey_free(public);
-			first = 0;
-			continue;
+			goto failnext;
 		}
 		fprintf(f, " %s\n", comment);
-		fclose(f);
-		sshkey_free(public);
+		if (ferror(f) != 0) {
+			error("write key failed: %s", strerror(errno));
+			fclose(f);
+			goto failnext;
+		}
+		if (fclose(f) != 0) {
+			error("key close failed: %s", strerror(errno));
+			goto failnext;
+		}
 
+		/* Rename temporary files to their permanent locations. */
+		if (rename(pub_tmp, pub_file) != 0) {
+			error("Unable to move %s into position: %s",
+			    pub_file, strerror(errno));
+			goto failnext;
+		}
+		if (rename(prv_tmp, prv_file) != 0) {
+			error("Unable to move %s into position: %s",
+			    key_types[i].path, strerror(errno));
+ failnext:
+			first = 0;
+			goto next;
+		}
+ next:
+		sshkey_free(private);
+		sshkey_free(public);
+		free(prv_tmp);
+		free(pub_tmp);
+		free(prv_file);
+		free(pub_file);
 	}
 	if (first != 0)
 		printf("\n");
@@ -1059,6 +1091,9 @@
 	int has_unhashed;	/* When hashing, original had unhashed hosts */
 	int found_key;		/* For find/delete, host was found */
 	int invalid;		/* File contained invalid items; don't delete */
+	int hash_hosts;		/* Hash hostnames as we go */
+	int find_host;		/* Search for specific hostname */
+	int delete_host;	/* Delete host from known_hosts */
 };
 
 static int
@@ -1067,6 +1102,7 @@
 	struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
 	char *hashed, *cp, *hosts, *ohosts;
 	int has_wild = l->hosts && strcspn(l->hosts, "*?!") != strlen(l->hosts);
+	int was_hashed = l->hosts && l->hosts[0] == HASH_DELIM;
 
 	switch (l->status) {
 	case HKF_STATUS_OK:
@@ -1075,11 +1111,10 @@
 		 * Don't hash hosts already already hashed, with wildcard
 		 * characters or a CA/revocation marker.
 		 */
-		if ((l->match & HKF_MATCH_HOST_HASHED) != 0 ||
-		    has_wild || l->marker != MRK_NONE) {
+		if (was_hashed || has_wild || l->marker != MRK_NONE) {
 			fprintf(ctx->out, "%s\n", l->line);
-			if (has_wild && !find_host) {
-				logit("%s:%ld: ignoring host name "
+			if (has_wild && !ctx->find_host) {
+				logit("%s:%lu: ignoring host name "
 				    "with wildcard: %.64s", l->path,
 				    l->linenum, l->hosts);
 			}
@@ -1091,6 +1126,7 @@
 		 */
 		ohosts = hosts = xstrdup(l->hosts);
 		while ((cp = strsep(&hosts, ",")) != NULL && *cp != '\0') {
+			lowercase(cp);
 			if ((hashed = host_hash(cp, NULL, 0)) == NULL)
 				fatal("hash_host failed");
 			fprintf(ctx->out, "%s %s\n", hashed, l->rawkey);
@@ -1101,7 +1137,7 @@
 	case HKF_STATUS_INVALID:
 		/* Retain invalid lines, but mark file as invalid. */
 		ctx->invalid = 1;
-		logit("%s:%ld: invalid line", l->path, l->linenum);
+		logit("%s:%lu: invalid line", l->path, l->linenum);
 		/* FALLTHROUGH */
 	default:
 		fprintf(ctx->out, "%s\n", l->line);
@@ -1123,7 +1159,7 @@
 	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
 
 	if (l->status == HKF_STATUS_MATCHED) {
-		if (delete_host) {
+		if (ctx->delete_host) {
 			if (l->marker != MRK_NONE) {
 				/* Don't remove CA and revocation lines */
 				fprintf(ctx->out, "%s\n", l->line);
@@ -1135,34 +1171,34 @@
 				 */
 				ctx->found_key = 1;
 				if (!quiet)
-					printf("# Host %s found: line %ld\n",
+					printf("# Host %s found: line %lu\n",
 					    ctx->host, l->linenum);
 			}
 			return 0;
-		} else if (find_host) {
+		} else if (ctx->find_host) {
 			ctx->found_key = 1;
 			if (!quiet) {
-				printf("# Host %s found: line %ld %s\n",
+				printf("# Host %s found: line %lu %s\n",
 				    ctx->host,
 				    l->linenum, l->marker == MRK_CA ? "CA" :
 				    (l->marker == MRK_REVOKE ? "REVOKED" : ""));
 			}
-			if (hash_hosts)
+			if (ctx->hash_hosts)
 				known_hosts_hash(l, ctx);
 			else if (print_fingerprint) {
 				fp = sshkey_fingerprint(l->key, fptype, rep);
-				printf("%s %s %s %s\n", ctx->host,
+				mprintf("%s %s %s %s\n", ctx->host,
 				    sshkey_type(l->key), fp, l->comment);
 				free(fp);
 			} else
 				fprintf(ctx->out, "%s\n", l->line);
 			return 0;
 		}
-	} else if (delete_host) {
+	} else if (ctx->delete_host) {
 		/* Retain non-matching hosts when deleting */
 		if (l->status == HKF_STATUS_INVALID) {
 			ctx->invalid = 1;
-			logit("%s:%ld: invalid line", l->path, l->linenum);
+			logit("%s:%lu: invalid line", l->path, l->linenum);
 		}
 		fprintf(ctx->out, "%s\n", l->line);
 	}
@@ -1170,7 +1206,8 @@
 }
 
 static void
-do_known_hosts(struct passwd *pw, const char *name)
+do_known_hosts(struct passwd *pw, const char *name, int find_host,
+    int delete_host, int hash_hosts)
 {
 	char *cp, tmp[PATH_MAX], old[PATH_MAX];
 	int r, fd, oerrno, inplace = 0;
@@ -1189,6 +1226,9 @@
 	memset(&ctx, 0, sizeof(ctx));
 	ctx.out = stdout;
 	ctx.host = name;
+	ctx.hash_hosts = hash_hosts;
+	ctx.find_host = find_host;
+	ctx.delete_host = delete_host;
 
 	/*
 	 * Find hosts goes to stdout, hash and deletions happen in-place
@@ -1210,13 +1250,12 @@
 		}
 		inplace = 1;
 	}
-
 	/* XXX support identity_file == "-" for stdin */
 	foreach_options = find_host ? HKF_WANT_MATCH : 0;
 	foreach_options |= print_fingerprint ? HKF_WANT_PARSE_KEY : 0;
-	if ((r = hostkeys_foreach(identity_file,
-	    hash_hosts ? known_hosts_hash : known_hosts_find_delete, &ctx,
-	    name, NULL, foreach_options)) != 0) {
+	if ((r = hostkeys_foreach(identity_file, (find_host || !hash_hosts) ?
+	    known_hosts_find_delete : known_hosts_hash, &ctx, name, NULL,
+	    foreach_options)) != 0) {
 		if (inplace)
 			unlink(tmp);
 		fatal("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
@@ -1302,7 +1341,7 @@
 		fatal("Failed to load key %s: %s", identity_file, ssh_err(r));
 	}
 	if (comment)
-		printf("Key has comment '%s'\n", comment);
+		mprintf("Key has comment '%s'\n", comment);
 
 	/* Ask the new passphrase (twice). */
 	if (identity_new_passphrase) {
@@ -1354,7 +1393,8 @@
  * Print the SSHFP RR.
  */
 static int
-do_print_resource_record(struct passwd *pw, char *fname, char *hname)
+do_print_resource_record(struct passwd *pw, char *fname, char *hname,
+    int print_generic)
 {
 	struct sshkey *public;
 	char *comment = NULL;
@@ -1381,7 +1421,7 @@
  * Change the comment of a private key file.
  */
 static void
-do_change_comment(struct passwd *pw)
+do_change_comment(struct passwd *pw, const char *identity_comment)
 {
 	char new_comment[1024], *comment, *passphrase;
 	struct sshkey *private;
@@ -1418,20 +1458,23 @@
 		}
 	}
 
-	if (private->type != KEY_RSA1 && private->type != KEY_ED25519 &&
+	if (private->type != KEY_ED25519 && private->type != KEY_XMSS &&
 	    !use_new_format) {
-		error("Comments are only supported for RSA1 or keys stored in "
+		error("Comments are only supported for keys stored in "
 		    "the new format (-o).");
 		explicit_bzero(passphrase, strlen(passphrase));
 		sshkey_free(private);
 		exit(1);
 	}
-	printf("Key now has comment '%s'\n", comment);
+	if (comment)
+		printf("Old comment: %s\n", comment);
+	else
+		printf("No existing comment\n");
 
 	if (identity_comment) {
 		strlcpy(new_comment, identity_comment, sizeof(new_comment));
 	} else {
-		printf("Enter new comment: ");
+		printf("New comment: ");
 		fflush(stdout);
 		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
 			explicit_bzero(passphrase, strlen(passphrase));
@@ -1440,6 +1483,13 @@
 		}
 		new_comment[strcspn(new_comment, "\n")] = '\0';
 	}
+	if (comment != NULL && strcmp(comment, new_comment) == 0) {
+		printf("No change to comment\n");
+		free(passphrase);
+		sshkey_free(private);
+		free(comment);
+		exit(0);
+	}
 
 	/* Save the file using the new passphrase. */
 	if ((r = sshkey_save_private(private, identity_file, passphrase,
@@ -1455,7 +1505,7 @@
 	explicit_bzero(passphrase, strlen(passphrase));
 	free(passphrase);
 	if ((r = sshkey_from_private(private, &public)) != 0)
-		fatal("key_from_private failed: %s", ssh_err(r));
+		fatal("sshkey_from_private failed: %s", ssh_err(r));
 	sshkey_free(private);
 
 	strlcat(identity_file, ".pub", sizeof(identity_file));
@@ -1473,7 +1523,11 @@
 
 	free(comment);
 
-	printf("The comment in your key file has been changed.\n");
+	if (strlen(new_comment) > 0)
+		printf("Comment '%s' applied\n", new_comment);
+	else
+		printf("Comment removed\n");
+
 	exit(0);
 }
 
@@ -1510,6 +1564,8 @@
 static void
 prepare_options_buf(struct sshbuf *c, int which)
 {
+	size_t i;
+
 	sshbuf_reset(c);
 	if ((which & OPTIONS_CRITICAL) != 0 &&
 	    certflags_command != NULL)
@@ -1532,6 +1588,17 @@
 	if ((which & OPTIONS_CRITICAL) != 0 &&
 	    certflags_src_addr != NULL)
 		add_string_option(c, "source-address", certflags_src_addr);
+	for (i = 0; i < ncert_userext; i++) {
+		if ((cert_userext[i].crit && (which & OPTIONS_EXTENSIONS)) ||
+		    (!cert_userext[i].crit && (which & OPTIONS_CRITICAL)))
+			continue;
+		if (cert_userext[i].val == NULL)
+			add_flag_option(c, cert_userext[i].key);
+		else {
+			add_string_option(c, cert_userext[i].key,
+			    cert_userext[i].val);
+		}
+	}
 }
 
 static struct sshkey *
@@ -1564,26 +1631,76 @@
 #endif /* ENABLE_PKCS11 */
 }
 
+/* Signer for sshkey_certify_custom that uses the agent */
+static int
+agent_signer(struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen,
+    const char *alg, u_int compat, void *ctx)
+{
+	int *agent_fdp = (int *)ctx;
+
+	return ssh_agent_sign(*agent_fdp, key, sigp, lenp,
+	    data, datalen, alg, compat);
+}
+
 static void
-do_ca_sign(struct passwd *pw, int argc, char **argv)
+do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
+    unsigned long long cert_serial, int cert_serial_autoinc,
+    int argc, char **argv)
 {
-	int r, i, fd;
+	int r, i, fd, found, agent_fd = -1;
 	u_int n;
 	struct sshkey *ca, *public;
 	char valid[64], *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
 	FILE *f;
+	struct ssh_identitylist *agent_ids;
+	size_t j;
 
 #ifdef ENABLE_PKCS11
 	pkcs11_init(1);
 #endif
 	tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
 	if (pkcs11provider != NULL) {
+		/* If a PKCS#11 token was specified then try to use it */
 		if ((ca = load_pkcs11_key(tmp)) == NULL)
 			fatal("No PKCS#11 key matching %s found", ca_key_path);
-	} else
+	} else if (prefer_agent) {
+		/*
+		 * Agent signature requested. Try to use agent after making
+		 * sure the public key specified is actually present in the
+		 * agent.
+		 */
+		if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
+			fatal("Cannot load CA public key %s: %s",
+			    tmp, ssh_err(r));
+		if ((r = ssh_get_authentication_socket(&agent_fd)) != 0)
+			fatal("Cannot use public key for CA signature: %s",
+			    ssh_err(r));
+		if ((r = ssh_fetch_identitylist(agent_fd, &agent_ids)) != 0)
+			fatal("Retrieve agent key list: %s", ssh_err(r));
+		found = 0;
+		for (j = 0; j < agent_ids->nkeys; j++) {
+			if (sshkey_equal(ca, agent_ids->keys[j])) {
+				found = 1;
+				break;
+			}
+		}
+		if (!found)
+			fatal("CA key %s not found in agent", tmp);
+		ssh_free_identitylist(agent_ids);
+		ca->flags |= SSHKEY_FLAG_EXT;
+	} else {
+		/* CA key is assumed to be a private key on the filesystem */
 		ca = load_identity(tmp);
+	}
 	free(tmp);
 
+	if (key_type_name != NULL &&
+	    sshkey_type_from_name(key_type_name) != ca->type)  {
+		fatal("CA key type %s doesn't match specified %s",
+		    sshkey_ssh_name(ca), key_type_name);
+	}
+
 	for (i = 0; i < argc; i++) {
 		/* Split list of principals */
 		n = 0;
@@ -1597,13 +1714,16 @@
 			}
 			free(otmp);
 		}
+		if (n > SSHKEY_CERT_MAX_PRINCIPALS)
+			fatal("Too many certificate principals specified");
 	
 		tmp = tilde_expand_filename(argv[i], pw->pw_uid);
 		if ((r = sshkey_load_public(tmp, &public, &comment)) != 0)
 			fatal("%s: unable to open \"%s\": %s",
 			    __func__, tmp, ssh_err(r));
 		if (public->type != KEY_RSA && public->type != KEY_DSA &&
-		    public->type != KEY_ECDSA && public->type != KEY_ED25519)
+		    public->type != KEY_ECDSA && public->type != KEY_ED25519 &&
+		    public->type != KEY_XMSS)
 			fatal("%s: key \"%s\" type %s cannot be certified",
 			    __func__, tmp, sshkey_type(public));
 
@@ -1623,10 +1743,18 @@
 		    OPTIONS_EXTENSIONS);
 		if ((r = sshkey_from_private(ca,
 		    &public->cert->signature_key)) != 0)
-			fatal("key_from_private (ca key): %s", ssh_err(r));
+			fatal("sshkey_from_private (ca key): %s", ssh_err(r));
 
-		if (sshkey_certify(public, ca) != 0)
-			fatal("Couldn't not certify key %s", tmp);
+		if (agent_fd != -1 && (ca->flags & SSHKEY_FLAG_EXT) != 0) {
+			if ((r = sshkey_certify_custom(public, ca,
+			    key_type_name, agent_signer, &agent_fd)) != 0)
+				fatal("Couldn't certify key %s via agent: %s",
+				    tmp, ssh_err(r));
+		} else {
+			if ((sshkey_certify(public, ca, key_type_name)) != 0)
+				fatal("Couldn't certify key %s: %s",
+				    tmp, ssh_err(r));
+		}
 
 		if ((cp = strrchr(tmp, '.')) != NULL && strcmp(cp, ".pub") == 0)
 			*cp = '\0';
@@ -1658,6 +1786,8 @@
 
 		sshkey_free(public);
 		free(out);
+		if (cert_serial_autoinc)
+			cert_serial++;
 	}
 #ifdef ENABLE_PKCS11
 	pkcs11_terminate();
@@ -1679,40 +1809,6 @@
 	return now + (u_int64_t)(secs * mul);
 }
 
-static u_int64_t
-parse_absolute_time(const char *s)
-{
-	struct tm tm;
-	time_t tt;
-	char buf[32], *fmt;
-
-	/*
-	 * POSIX strptime says "The application shall ensure that there
-	 * is white-space or other non-alphanumeric characters between
-	 * any two conversion specifications" so arrange things this way.
-	 */
-	switch (strlen(s)) {
-	case 8:
-		fmt = "%Y-%m-%d";
-		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
-		break;
-	case 14:
-		fmt = "%Y-%m-%dT%H:%M:%S";
-		snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
-		    s, s + 4, s + 6, s + 8, s + 10, s + 12);
-		break;
-	default:
-		fatal("Invalid certificate time format %s", s);
-	}
-
-	memset(&tm, 0, sizeof(tm));
-	if (strptime(buf, fmt, &tm) == NULL)
-		fatal("Invalid certificate time %s", s);
-	if ((tt = mktime(&tm)) < 0)
-		fatal("Certificate time %s cannot be represented", s);
-	return (u_int64_t)tt;
-}
-
 static void
 parse_cert_times(char *timespec)
 {
@@ -1735,8 +1831,8 @@
 
 	/*
 	 * from:to, where
-	 * from := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS
-	 *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS
+	 * from := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "always"
+	 *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "forever"
 	 */
 	from = xstrdup(timespec);
 	to = strchr(from, ':');
@@ -1746,13 +1842,17 @@
 
 	if (*from == '-' || *from == '+')
 		cert_valid_from = parse_relative_time(from, now);
-	else
-		cert_valid_from = parse_absolute_time(from);
+	else if (strcmp(from, "always") == 0)
+		cert_valid_from = 0;
+	else if (parse_absolute_time(from, &cert_valid_from) != 0)
+		fatal("Invalid from time \"%s\"", from);
 
 	if (*to == '-' || *to == '+')
 		cert_valid_to = parse_relative_time(to, now);
-	else
-		cert_valid_to = parse_absolute_time(to);
+	else if (strcmp(to, "forever") == 0)
+		cert_valid_to = ~(u_int64_t)0;
+	else if (parse_absolute_time(to, &cert_valid_to) != 0)
+		fatal("Invalid to time \"%s\"", to);
 
 	if (cert_valid_to <= cert_valid_from)
 		fatal("Empty certificate validity interval");
@@ -1762,7 +1862,8 @@
 static void
 add_cert_option(char *opt)
 {
-	char *val;
+	char *val, *cp;
+	int iscrit = 0;
 
 	if (strcasecmp(opt, "clear") == 0)
 		certflags_flags = 0;
@@ -1802,6 +1903,18 @@
 		if (addr_match_cidr_list(NULL, val) != 0)
 			fatal("Invalid source-address list");
 		certflags_src_addr = xstrdup(val);
+	} else if (strncasecmp(opt, "extension:", 10) == 0 ||
+		   (iscrit = (strncasecmp(opt, "critical:", 9) == 0))) {
+		val = xstrdup(strchr(opt, ':') + 1);
+		if ((cp = strchr(val, '=')) != NULL)
+			*cp++ = '\0';
+		cert_userext = xreallocarray(cert_userext, ncert_userext + 1,
+		    sizeof(*cert_userext));
+		cert_userext[ncert_userext].key = val;
+		cert_userext[ncert_userext].val = cp == NULL ?
+		    NULL : xstrdup(cp);
+		cert_userext[ncert_userext].crit = iscrit;
+		ncert_userext++;
 	} else
 		fatal("Unsupported certificate option \"%s\"", opt);
 }
@@ -1866,8 +1979,9 @@
 	printf("        Type: %s %s certificate\n", sshkey_ssh_name(key),
 	    sshkey_cert_type(key));
 	printf("        Public key: %s %s\n", sshkey_type(key), key_fp);
-	printf("        Signing CA: %s %s\n",
-	    sshkey_type(key->cert->signature_key), ca_fp);
+	printf("        Signing CA: %s %s (using %s)\n",
+	    sshkey_type(key->cert->signature_key), ca_fp,
+	    key->cert->signature_type);
 	printf("        Key ID: \"%s\"\n", key->cert->key_id);
 	printf("        Serial: %llu\n", (unsigned long long)key->cert->serial);
 	printf("        Valid: %s\n", valid);
@@ -1903,9 +2017,10 @@
 	struct stat st;
 	int r, is_stdin = 0, ok = 0;
 	FILE *f;
-	char *cp, line[SSH_MAX_PUBKEY_BYTES];
+	char *cp, *line = NULL;
 	const char *path;
-	long int lnum = 0;
+	size_t linesize = 0;
+	u_long lnum = 0;
 
 	if (!have_identity)
 		ask_filename(pw, "Enter file in which the key is");
@@ -1920,7 +2035,8 @@
 	} else if ((f = fopen(identity_file, "r")) == NULL)
 		fatal("fopen %s: %s", identity_file, strerror(errno));
 
-	while (read_keyfile_line(f, path, line, sizeof(line), &lnum) == 0) {
+	while (getline(&line, &linesize, f) != -1) {
+		lnum++;
 		sshkey_free(key);
 		key = NULL;
 		/* Trim leading space and comments */
@@ -1928,7 +2044,7 @@
 		if (*cp == '#' || *cp == '\0')
 			continue;
 		if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
-			fatal("key_new");
+			fatal("sshkey_new");
 		if ((r = sshkey_read(key, &cp)) != 0) {
 			error("%s:%lu: invalid key: %s", path,
 			    lnum, ssh_err(r));
@@ -1945,6 +2061,7 @@
 			printf("%s:%lu:\n", path, lnum);
 		print_cert(key);
 	}
+	free(line);
 	sshkey_free(key);
 	fclose(f);
 	exit(ok ? 0 : 1);
@@ -1972,14 +2089,51 @@
 }
 
 static void
+hash_to_blob(const char *cp, u_char **blobp, size_t *lenp,
+    const char *file, u_long lnum)
+{
+	char *tmp;
+	size_t tlen;
+	struct sshbuf *b;
+	int r;
+
+	if (strncmp(cp, "SHA256:", 7) != 0)
+		fatal("%s:%lu: unsupported hash algorithm", file, lnum);
+	cp += 7;
+
+	/*
+	 * OpenSSH base64 hashes omit trailing '='
+	 * characters; put them back for decode.
+	 */
+	tlen = strlen(cp);
+	tmp = xmalloc(tlen + 4 + 1);
+	strlcpy(tmp, cp, tlen + 1);
+	while ((tlen % 4) != 0) {
+		tmp[tlen++] = '=';
+		tmp[tlen] = '\0';
+	}
+	if ((b = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_b64tod(b, tmp)) != 0)
+		fatal("%s:%lu: decode hash failed: %s", file, lnum, ssh_err(r));
+	free(tmp);
+	*lenp = sshbuf_len(b);
+	*blobp = xmalloc(*lenp);
+	memcpy(*blobp, sshbuf_ptr(b), *lenp);
+	sshbuf_free(b);
+}
+
+static void
 update_krl_from_file(struct passwd *pw, const char *file, int wild_ca,
     const struct sshkey *ca, struct ssh_krl *krl)
 {
 	struct sshkey *key = NULL;
 	u_long lnum = 0;
-	char *path, *cp, *ep, line[SSH_MAX_PUBKEY_BYTES];
+	char *path, *cp, *ep, *line = NULL;
+	u_char *blob = NULL;
+	size_t blen = 0, linesize = 0;
 	unsigned long long serial, serial2;
-	int i, was_explicit_key, was_sha1, r;
+	int i, was_explicit_key, was_sha1, was_sha256, was_hash, r;
 	FILE *krl_spec;
 
 	path = tilde_expand_filename(file, pw->pw_uid);
@@ -1992,9 +2146,9 @@
 
 	if (!quiet)
 		printf("Revoking from %s\n", path);
-	while (read_keyfile_line(krl_spec, path, line, sizeof(line),
-	    &lnum) == 0) {
-		was_explicit_key = was_sha1 = 0;
+	while (getline(&line, &linesize, krl_spec) != -1) {
+		lnum++;
+		was_explicit_key = was_sha1 = was_sha256 = was_hash = 0;
 		cp = line + strspn(line, " \t");
 		/* Trim trailing space, comments and strip \n */
 		for (i = 0, r = -1; cp[i] != '\0'; i++) {
@@ -2059,6 +2213,11 @@
 			cp = cp + strspn(cp, " \t");
 			if (ssh_krl_revoke_cert_by_key_id(krl, ca, cp) != 0)
 				fatal("%s: revoke key ID failed", __func__);
+		} else if (strncasecmp(cp, "hash:", 5) == 0) {
+			cp += 5;
+			cp = cp + strspn(cp, " \t");
+			hash_to_blob(cp, &blob, &blen, file, lnum);
+			r = ssh_krl_revoke_key_sha256(krl, blob, blen);
 		} else {
 			if (strncasecmp(cp, "key:", 4) == 0) {
 				cp += 4;
@@ -2068,36 +2227,57 @@
 				cp += 5;
 				cp = cp + strspn(cp, " \t");
 				was_sha1 = 1;
-			} else {
+			} else if (strncasecmp(cp, "sha256:", 7) == 0) {
+				cp += 7;
+				cp = cp + strspn(cp, " \t");
+				was_sha256 = 1;
 				/*
 				 * Just try to process the line as a key.
 				 * Parsing will fail if it isn't.
 				 */
 			}
 			if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
-				fatal("key_new");
+				fatal("sshkey_new");
 			if ((r = sshkey_read(key, &cp)) != 0)
 				fatal("%s:%lu: invalid key: %s",
 				    path, lnum, ssh_err(r));
 			if (was_explicit_key)
 				r = ssh_krl_revoke_key_explicit(krl, key);
-			else if (was_sha1)
-				r = ssh_krl_revoke_key_sha1(krl, key);
-			else
+			else if (was_sha1) {
+				if (sshkey_fingerprint_raw(key,
+				    SSH_DIGEST_SHA1, &blob, &blen) != 0) {
+					fatal("%s:%lu: fingerprint failed",
+					    file, lnum);
+				}
+				r = ssh_krl_revoke_key_sha1(krl, blob, blen);
+			} else if (was_sha256) {
+				if (sshkey_fingerprint_raw(key,
+				    SSH_DIGEST_SHA256, &blob, &blen) != 0) {
+					fatal("%s:%lu: fingerprint failed",
+					    file, lnum);
+				}
+				r = ssh_krl_revoke_key_sha256(krl, blob, blen);
+			} else
 				r = ssh_krl_revoke_key(krl, key);
 			if (r != 0)
 				fatal("%s: revoke key failed: %s",
 				    __func__, ssh_err(r));
+			freezero(blob, blen);
+			blob = NULL;
+			blen = 0;
 			sshkey_free(key);
 		}
 	}
 	if (strcmp(path, "-") != 0)
 		fclose(krl_spec);
+	free(line);
 	free(path);
 }
 
 static void
-do_gen_krl(struct passwd *pw, int updating, int argc, char **argv)
+do_gen_krl(struct passwd *pw, int updating, const char *ca_key_path,
+    unsigned long long krl_version, const char *krl_comment,
+    int argc, char **argv)
 {
 	struct ssh_krl *krl;
 	struct stat sb;
@@ -2132,10 +2312,10 @@
 	else if ((krl = ssh_krl_init()) == NULL)
 		fatal("couldn't create KRL");
 
-	if (cert_serial != 0)
-		ssh_krl_set_version(krl, cert_serial);
-	if (identity_comment != NULL)
-		ssh_krl_set_comment(krl, identity_comment);
+	if (krl_version != 0)
+		ssh_krl_set_version(krl, krl_version);
+	if (krl_comment != NULL)
+		ssh_krl_set_comment(krl, krl_comment);
 
 	for (i = 0; i < argc; i++)
 		update_krl_from_file(pw, argv[i], wild_ca, ca, krl);
@@ -2146,7 +2326,7 @@
 		fatal("Couldn't generate KRL");
 	if ((fd = open(identity_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
 		fatal("open %s: %s", identity_file, strerror(errno));
-	if (atomicio(vwrite, fd, (void *)sshbuf_ptr(kbuf), sshbuf_len(kbuf)) !=
+	if (atomicio(vwrite, fd, sshbuf_mutable_ptr(kbuf), sshbuf_len(kbuf)) !=
 	    sshbuf_len(kbuf))
 		fatal("write %s: %s", identity_file, strerror(errno));
 	close(fd);
@@ -2188,9 +2368,10 @@
 usage(void)
 {
 	fprintf(stderr,
-	    "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa | rsa1]\n"
+	    "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa] [-m format]\n"
 	    "                  [-N new_passphrase] [-C comment] [-f output_keyfile]\n"
-	    "       ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile]\n"
+	    "       ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-m format]\n"
+	    "                   [-f keyfile]\n"
 	    "       ssh-keygen -i [-m key_format] [-f input_keyfile]\n"
 	    "       ssh-keygen -e [-m key_format] [-f input_keyfile]\n"
 	    "       ssh-keygen -y [-f input_keyfile]\n"
@@ -2211,8 +2392,9 @@
 	    "       ssh-keygen -T output_file -f input_file [-v] [-a rounds] [-J num_lines]\n"
 	    "                  [-j start_line] [-K checkpt] [-W generator]\n"
 #endif
-	    "       ssh-keygen -s ca_key -I certificate_identity [-h] [-n principals]\n"
-	    "                  [-O option] [-V validity_interval] [-z serial_number] file ...\n"
+	    "       ssh-keygen -s ca_key -I certificate_identity [-h] [-U]\n"
+	    "                  [-D pkcs11_provider] [-n principals] [-O option]\n"
+	    "                  [-V validity_interval] [-z serial_number] file ...\n"
 	    "       ssh-keygen -L [-f input_keyfile]\n"
 	    "       ssh-keygen -A\n"
 	    "       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]\n"
@@ -2233,9 +2415,17 @@
 	struct passwd *pw;
 	struct stat st;
 	int r, opt, type, fd;
+	int change_passphrase = 0, change_comment = 0, show_cert = 0;
+	int find_host = 0, delete_host = 0, hash_hosts = 0;
 	int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
+	int prefer_agent = 0, convert_to = 0, convert_from = 0;
+	int print_public = 0, print_generic = 0, cert_serial_autoinc = 0;
+	unsigned long long cert_serial = 0;
+	char *identity_comment = NULL, *ca_key_path = NULL;
+	u_int bits = 0;
 	FILE *f;
 	const char *errstr;
+	int log_level = SYSLOG_LEVEL_INFO;
 #ifdef WITH_OPENSSL
 	/* Moduli generation/screening */
 	char out_file[PATH_MAX], *checkpoint = NULL;
@@ -2248,13 +2438,14 @@
 	extern int optind;
 	extern char *optarg;
 
-	ssh_malloc_init();	/* must be called before any mallocs */
 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();
 
 	OpenSSL_add_all_algorithms();
 	log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
 
+	setlocale(LC_CTYPE, "");
+
 	/* we need this for the home * directory.  */
 	pw = getpwuid(getuid());
 	if (!pw)
@@ -2262,8 +2453,8 @@
 	if (gethostname(hostname, sizeof(hostname)) < 0)
 		fatal("gethostname: %s", strerror(errno));
 
-	/* Remaining characters: UYdw */
-	while ((opt = getopt(argc, argv, "ABHLQXceghiklopquvxy"
+	/* Remaining characters: Ydw */
+	while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvxy"
 	    "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Z:"
 	    "a:b:f:g:j:m:n:r:s:t:z:")) != -1) {
 		switch (opt) {
@@ -2271,7 +2462,7 @@
 			gen_all_hostkeys = 1;
 			break;
 		case 'b':
-			bits = (u_int32_t)strtonum(optarg, 256, 32768, &errstr);
+			bits = (u_int32_t)strtonum(optarg, 10, 32768, &errstr);
 			if (errstr)
 				fatal("Bits has bad value %s (%s)",
 					optarg, errstr);
@@ -2316,6 +2507,7 @@
 			}
 			if (strcasecmp(optarg, "PEM") == 0) {
 				convert_format = FMT_PEM;
+				use_new_format = 0;
 				break;
 			}
 			fatal("Unsupported conversion format \"%s\"", optarg);
@@ -2323,7 +2515,7 @@
 			cert_principals = optarg;
 			break;
 		case 'o':
-			use_new_format = 1;
+			/* no-op; new format is already the default */
 			break;
 		case 'p':
 			change_passphrase = 1;
@@ -2390,6 +2582,9 @@
 		case 'D':
 			pkcs11provider = optarg;
 			break;
+		case 'U':
+			prefer_agent = 1;
+			break;
 		case 'u':
 			update_krl = 1;
 			break;
@@ -2416,6 +2611,10 @@
 			break;
 		case 'z':
 			errno = 0;
+			if (*optarg == '+') {
+				cert_serial_autoinc = 1;
+				optarg++;
+			}
 			cert_serial = strtoull(optarg, &ep, 10);
 			if (*optarg < '0' || *optarg > '9' || *ep != '\0' ||
 			    (errno == ERANGE && cert_serial == ULLONG_MAX))
@@ -2431,10 +2630,10 @@
 			break;
 		case 'J':
 			lines_to_process = strtoul(optarg, NULL, 10);
-                        break;
+			break;
 		case 'j':
 			start_lineno = strtoul(optarg, NULL, 10);
-                        break;
+			break;
 		case 'K':
 			if (strlen(optarg) >= PATH_MAX)
 				fatal("Checkpoint filename too long");
@@ -2496,7 +2695,8 @@
 	}
 #ifdef WITH_OPENSSL
 	if (gen_krl) {
-		do_gen_krl(pw, update_krl, argc, argv);
+		do_gen_krl(pw, update_krl, ca_key_path,
+		    cert_serial, identity_comment, argc, argv);
 		return (0);
 	}
 	if (check_krl) {
@@ -2507,12 +2707,15 @@
 	if (ca_key_path != NULL) {
 		if (cert_key_id == NULL)
 			fatal("Must specify key id (-I) when certifying");
-		do_ca_sign(pw, argc, argv);
+		do_ca_sign(pw, ca_key_path, prefer_agent,
+		    cert_serial, cert_serial_autoinc, argc, argv);
 	}
 	if (show_cert)
 		do_show_cert(pw);
-	if (delete_host || hash_hosts || find_host)
-		do_known_hosts(pw, rr_hostname);
+	if (delete_host || hash_hosts || find_host) {
+		do_known_hosts(pw, rr_hostname, find_host,
+		    delete_host, hash_hosts);
+	}
 	if (pkcs11provider != NULL)
 		do_download(pw);
 	if (print_fingerprint || print_bubblebabble)
@@ -2520,7 +2723,7 @@
 	if (change_passphrase)
 		do_change_passphrase(pw);
 	if (change_comment)
-		do_change_comment(pw);
+		do_change_comment(pw, identity_comment);
 #ifdef WITH_OPENSSL
 	if (convert_to)
 		do_convert_to(pw);
@@ -2533,21 +2736,28 @@
 		unsigned int n = 0;
 
 		if (have_identity) {
-			n = do_print_resource_record(pw,
-			    identity_file, rr_hostname);
+			n = do_print_resource_record(pw, identity_file,
+			    rr_hostname, print_generic);
 			if (n == 0)
 				fatal("%s: %s", identity_file, strerror(errno));
 			exit(0);
 		} else {
 
 			n += do_print_resource_record(pw,
-			    _PATH_HOST_RSA_KEY_FILE, rr_hostname);
+			    _PATH_HOST_RSA_KEY_FILE, rr_hostname,
+			    print_generic);
 			n += do_print_resource_record(pw,
-			    _PATH_HOST_DSA_KEY_FILE, rr_hostname);
+			    _PATH_HOST_DSA_KEY_FILE, rr_hostname,
+			    print_generic);
 			n += do_print_resource_record(pw,
-			    _PATH_HOST_ECDSA_KEY_FILE, rr_hostname);
+			    _PATH_HOST_ECDSA_KEY_FILE, rr_hostname,
+			    print_generic);
 			n += do_print_resource_record(pw,
-			    _PATH_HOST_ED25519_KEY_FILE, rr_hostname);
+			    _PATH_HOST_ED25519_KEY_FILE, rr_hostname,
+			    print_generic);
+			n += do_print_resource_record(pw,
+			    _PATH_HOST_XMSS_KEY_FILE, rr_hostname,
+			    print_generic);
 			if (n == 0)
 				fatal("no keys found.");
 			exit(0);
@@ -2611,9 +2821,9 @@
 		printf("Generating public/private %s key pair.\n",
 		    key_type_name);
 	if ((r = sshkey_generate(type, bits, &private)) != 0)
-		fatal("key_generate failed");
+		fatal("sshkey_generate failed");
 	if ((r = sshkey_from_private(private, &public)) != 0)
-		fatal("key_from_private failed: %s\n", ssh_err(r));
+		fatal("sshkey_from_private failed: %s\n", ssh_err(r));
 
 	if (!have_identity)
 		ask_filename(pw, "Enter file in which to save the key");
@@ -2708,7 +2918,8 @@
 	if ((r = sshkey_write(public, f)) != 0)
 		error("write key failed: %s", ssh_err(r));
 	fprintf(f, " %s\n", comment);
-	fclose(f);
+	if (ferror(f) || fclose(f) != 0)
+		fatal("write public failed: %s", strerror(errno));
 
 	if (!quiet) {
 		fp = sshkey_fingerprint(public, fingerprint_hash,