Adding upstream version 1:7.9p1.upstream/1%7.9p1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2945 insertions, 0 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
new file mode 100644
index 0000000..46b3af5
--- /dev/null
+++ b/ssh-keygen.c
@@ -0,0 +1,2945 @@
+/* $OpenBSD: ssh-keygen.c,v 1.322 2018/09/14 04:17:44 djm Exp $ */
+/*
+ * Author: Tatu Ylonen <ylo@cs.hut.fi>
+ * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+ *                    All rights reserved
+ * Identity and host key generation and maintenance.
+ *
+ * As far as I am concerned, the code I have written for this software
+ * can be used freely for any purpose.  Any derived versions of this
+ * software must be clearly marked as such, and if the derived work is
+ * incompatible with the protocol description in the RFC file, it must be
+ * called by a name other than "ssh" or "Secure Shell".
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+
+#ifdef WITH_OPENSSL
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+#include "openbsd-compat/openssl-compat.h"
+#endif
+
+#include <errno.h>
+#include <fcntl.h>
+#include <netdb.h>
+#ifdef HAVE_PATHS_H
+# include <paths.h>
+#endif
+#include <pwd.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+#include <locale.h>
+#include <time.h>
+
+#include "xmalloc.h"
+#include "sshkey.h"
+#include "authfile.h"
+#include "uuencode.h"
+#include "sshbuf.h"
+#include "pathnames.h"
+#include "log.h"
+#include "misc.h"
+#include "match.h"
+#include "hostfile.h"
+#include "dns.h"
+#include "ssh.h"
+#include "ssh2.h"
+#include "ssherr.h"
+#include "ssh-pkcs11.h"
+#include "atomicio.h"
+#include "krl.h"
+#include "digest.h"
+#include "utf8.h"
+#include "authfd.h"
+
+#ifdef WITH_OPENSSL
+# define DEFAULT_KEY_TYPE_NAME "rsa"
+#else
+# 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
+#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;
+
+/*
+ * 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;
+
+/* Hash algorithm to use for fingerprints. */
+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;
+
+/* This is set to the passphrase if given on the command line. */
+char *identity_passphrase = NULL;
+
+/* This is set to the new passphrase if given on the command line. */
+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;
+
+/* Prefer to use agent keys for CA signing */
+int prefer_agent = 0;
+
+/* Certificate serial number */
+unsigned long long cert_serial = 0;
+
+/* Key type when certifying */
+u_int cert_key_type = SSH2_CERT_TYPE_USER;
+
+/* "key ID" of signed key */
+char *cert_key_id = NULL;
+
+/* Comma-separated list of principal names for certifying keys */
+char *cert_principals = NULL;
+
+/* Validity period for certificates */
+u_int64_t cert_valid_from = 0;
+u_int64_t cert_valid_to = ~0ULL;
+
+/* Certificate options */
+#define CERTOPT_X_FWD	(1)
+#define CERTOPT_AGENT_FWD	(1<<1)
+#define CERTOPT_PORT_FWD	(1<<2)
+#define CERTOPT_PTY		(1<<3)
+#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;
+
+/* Arbitrary extensions specified by user */
+struct cert_userext {
+	char *key;
+	char *val;
+	int crit;
+};
+struct cert_userext *cert_userext;
+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;
+
+/* Load key from this PKCS#11 provider */
+char *pkcs11provider = NULL;
+
+/* Use new OpenSSH private key format when writing SSH2 keys instead of PEM */
+int use_new_format = 1;
+
+/* Cipher for new-format private keys */
+char *new_format_cipher = NULL;
+
+/*
+ * Number of KDF rounds to derive new format keys /
+ * number of primality trials when screening moduli.
+ */
+int rounds = 0;
+
+/* argv0 */
+extern char *__progname;
+
+char hostname[NI_MAXHOST];
+
+#ifdef WITH_OPENSSL
+/* moduli.c */
+int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
+int prime_test(FILE *, FILE *, u_int32_t, u_int32_t, char *, unsigned long,
+    unsigned long);
+#endif
+
+static void
+type_bits_valid(int type, const char *name, u_int32_t *bitsp)
+{
+#ifdef WITH_OPENSSL
+	u_int maxbits, nid;
+#endif
+
+	if (type == KEY_UNSPEC)
+		fatal("unknown key type %s", key_type_name);
+	if (*bitsp == 0) {
+#ifdef WITH_OPENSSL
+		if (type == KEY_DSA)
+			*bitsp = DEFAULT_BITS_DSA;
+		else if (type == KEY_ECDSA) {
+			if (name != NULL &&
+			    (nid = sshkey_ecdsa_nid_from_name(name)) > 0)
+				*bitsp = sshkey_curve_nid_to_bits(nid);
+			if (*bitsp == 0)
+				*bitsp = DEFAULT_BITS_ECDSA;
+		} else
+#endif
+			*bitsp = DEFAULT_BITS;
+	}
+#ifdef WITH_OPENSSL
+	maxbits = (type == KEY_DSA) ?
+	    OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
+	if (*bitsp > maxbits)
+		fatal("key bits exceeds maximum %d", maxbits);
+	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
+}
+
+static void
+ask_filename(struct passwd *pw, const char *prompt)
+{
+	char buf[1024];
+	char *name = NULL;
+
+	if (key_type_name == NULL)
+		name = _PATH_SSH_CLIENT_ID_RSA;
+	else {
+		switch (sshkey_type_from_name(key_type_name)) {
+		case KEY_DSA_CERT:
+		case KEY_DSA:
+			name = _PATH_SSH_CLIENT_ID_DSA;
+			break;
+#ifdef OPENSSL_HAS_ECC
+		case KEY_ECDSA_CERT:
+		case KEY_ECDSA:
+			name = _PATH_SSH_CLIENT_ID_ECDSA;
+			break;
+#endif
+		case KEY_RSA_CERT:
+		case KEY_RSA:
+			name = _PATH_SSH_CLIENT_ID_RSA;
+			break;
+		case KEY_ED25519:
+		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");
+		}
+	}
+	snprintf(identity_file, sizeof(identity_file),
+	    "%s/%s", pw->pw_dir, name);
+	printf("%s (%s): ", prompt, identity_file);
+	fflush(stdout);
+	if (fgets(buf, sizeof(buf), stdin) == NULL)
+		exit(1);
+	buf[strcspn(buf, "\n")] = '\0';
+	if (strcmp(buf, "") != 0)
+		strlcpy(identity_file, buf, sizeof(identity_file));
+	have_identity = 1;
+}
+
+static struct sshkey *
+load_identity(char *filename)
+{
+	char *pass;
+	struct sshkey *prv;
+	int r;
+
+	if ((r = sshkey_load_private(filename, "", &prv, NULL)) == 0)
+		return prv;
+	if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
+		fatal("Load key \"%s\": %s", filename, ssh_err(r));
+	if (identity_passphrase)
+		pass = xstrdup(identity_passphrase);
+	else
+		pass = read_passphrase("Enter passphrase: ", RP_ALLOW_STDIN);
+	r = sshkey_load_private(filename, pass, &prv, NULL);
+	explicit_bzero(pass, strlen(pass));
+	free(pass);
+	if (r != 0)
+		fatal("Load key \"%s\": %s", filename, ssh_err(r));
+	return prv;
+}
+
+#define SSH_COM_PUBLIC_BEGIN		"---- BEGIN SSH2 PUBLIC KEY ----"
+#define SSH_COM_PUBLIC_END		"---- END SSH2 PUBLIC KEY ----"
+#define SSH_COM_PRIVATE_BEGIN		"---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
+#define	SSH_COM_PRIVATE_KEY_MAGIC	0x3f6ff9eb
+
+#ifdef WITH_OPENSSL
+static void
+do_convert_to_ssh2(struct passwd *pw, struct sshkey *k)
+{
+	size_t len;
+	u_char *blob;
+	char comment[61];
+	int r;
+
+	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) */
+	snprintf(comment, sizeof(comment),
+	    "%u-bit %s, converted by %s@%s from OpenSSH",
+	    sshkey_size(k), sshkey_type(k),
+	    pw->pw_name, hostname);
+
+	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
+	fprintf(stdout, "Comment: \"%s\"\n", comment);
+	dump_base64(stdout, blob, len);
+	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
+	sshkey_free(k);
+	free(blob);
+	exit(0);
+}
+
+static void
+do_convert_to_pkcs8(struct sshkey *k)
+{
+	switch (sshkey_type_plain(k->type)) {
+	case KEY_RSA:
+		if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
+			fatal("PEM_write_RSA_PUBKEY failed");
+		break;
+	case KEY_DSA:
+		if (!PEM_write_DSA_PUBKEY(stdout, k->dsa))
+			fatal("PEM_write_DSA_PUBKEY failed");
+		break;
+#ifdef OPENSSL_HAS_ECC
+	case KEY_ECDSA:
+		if (!PEM_write_EC_PUBKEY(stdout, k->ecdsa))
+			fatal("PEM_write_EC_PUBKEY failed");
+		break;
+#endif
+	default:
+		fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
+	}
+	exit(0);
+}
+
+static void
+do_convert_to_pem(struct sshkey *k)
+{
+	switch (sshkey_type_plain(k->type)) {
+	case KEY_RSA:
+		if (!PEM_write_RSAPublicKey(stdout, k->rsa))
+			fatal("PEM_write_RSAPublicKey failed");
+		break;
+	default:
+		fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
+	}
+	exit(0);
+}
+
+static void
+do_convert_to(struct passwd *pw)
+{
+	struct sshkey *k;
+	struct stat st;
+	int r;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+	if ((r = sshkey_load_public(identity_file, &k, NULL)) != 0)
+		k = load_identity(identity_file);
+	switch (convert_format) {
+	case FMT_RFC4716:
+		do_convert_to_ssh2(pw, k);
+		break;
+	case FMT_PKCS8:
+		do_convert_to_pkcs8(k);
+		break;
+	case FMT_PEM:
+		do_convert_to_pem(k);
+		break;
+	default:
+		fatal("%s: unknown key format %d", __func__, convert_format);
+	}
+	exit(0);
+}
+
+/*
+ * This is almost exactly the bignum1 encoding, but with 32 bit for length
+ * instead of 16.
+ */
+static void
+buffer_get_bignum_bits(struct sshbuf *b, BIGNUM *value)
+{
+	u_int bytes, bignum_bits;
+	int r;
+
+	if ((r = sshbuf_get_u32(b, &bignum_bits)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	bytes = (bignum_bits + 7) / 8;
+	if (sshbuf_len(b) < bytes)
+		fatal("%s: input buffer too small: need %d have %zu",
+		    __func__, bytes, sshbuf_len(b));
+	if (BN_bin2bn(sshbuf_ptr(b), bytes, value) == NULL)
+		fatal("%s: BN_bin2bn failed", __func__);
+	if ((r = sshbuf_consume(b, bytes)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+}
+
+static struct sshkey *
+do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
+{
+	struct sshbuf *b;
+	struct sshkey *key = NULL;
+	char *type, *cipher;
+	u_char e1, e2, e3, *sig = NULL, data[] = "abcde12345";
+	int r, rlen, ktype;
+	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)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+	if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
+		error("bad magic 0x%x != 0x%x", magic,
+		    SSH_COM_PRIVATE_KEY_MAGIC);
+		sshbuf_free(b);
+		return NULL;
+	}
+	if ((r = sshbuf_get_u32(b, &i1)) != 0 ||
+	    (r = sshbuf_get_cstring(b, &type, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(b, &cipher, NULL)) != 0 ||
+	    (r = sshbuf_get_u32(b, &i2)) != 0 ||
+	    (r = sshbuf_get_u32(b, &i3)) != 0 ||
+	    (r = sshbuf_get_u32(b, &i4)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+	debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
+	if (strcmp(cipher, "none") != 0) {
+		error("unsupported cipher %s", cipher);
+		free(cipher);
+		sshbuf_free(b);
+		free(type);
+		return NULL;
+	}
+	free(cipher);
+
+	if (strstr(type, "dsa")) {
+		ktype = KEY_DSA;
+	} else if (strstr(type, "rsa")) {
+		ktype = KEY_RSA;
+	} else {
+		sshbuf_free(b);
+		free(type);
+		return NULL;
+	}
+	if ((key = sshkey_new(ktype)) == NULL)
+		fatal("sshkey_new failed");
+	free(type);
+
+	switch (key->type) {
+	case KEY_DSA:
+		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 ||
+		    (e1 < 30 && (r = sshbuf_get_u8(b, &e2)) != 0) ||
+		    (e1 < 30 && (r = sshbuf_get_u8(b, &e3)) != 0))
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
+		e = e1;
+		debug("e %lx", e);
+		if (e < 30) {
+			e <<= 8;
+			e += e2;
+			debug("e %lx", e);
+			e <<= 8;
+			e += e3;
+			debug("e %lx", 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;
+		}
+		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);
+	if (rlen != 0)
+		error("do_convert_private_ssh2_from_blob: "
+		    "remaining bytes in key blob %d", rlen);
+	sshbuf_free(b);
+
+	/* try the key */
+	if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 ||
+	    sshkey_verify(key, sig, slen, data, sizeof(data), NULL, 0) != 0) {
+		sshkey_free(key);
+		free(sig);
+		return NULL;
+	}
+	free(sig);
+	return key;
+}
+
+static int
+get_line(FILE *fp, char *line, size_t len)
+{
+	int c;
+	size_t pos = 0;
+
+	line[0] = '\0';
+	while ((c = fgetc(fp)) != EOF) {
+		if (pos >= len - 1)
+			fatal("input line too long.");
+		switch (c) {
+		case '\r':
+			c = fgetc(fp);
+			if (c != EOF && c != '\n' && ungetc(c, fp) == EOF)
+				fatal("unget: %s", strerror(errno));
+			return pos;
+		case '\n':
+			return pos;
+		}
+		line[pos++] = c;
+		line[pos] = '\0';
+	}
+	/* We reached EOF */
+	return -1;
+}
+
+static void
+do_convert_from_ssh2(struct passwd *pw, struct sshkey **k, int *private)
+{
+	int r, blen, escaped = 0;
+	u_int len;
+	char line[1024];
+	u_char blob[8096];
+	char encoded[8096];
+	FILE *fp;
+
+	if ((fp = fopen(identity_file, "r")) == NULL)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+	encoded[0] = '\0';
+	while ((blen = get_line(fp, line, sizeof(line))) != -1) {
+		if (blen > 0 && line[blen - 1] == '\\')
+			escaped++;
+		if (strncmp(line, "----", 4) == 0 ||
+		    strstr(line, ": ") != NULL) {
+			if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
+				*private = 1;
+			if (strstr(line, " END ") != NULL) {
+				break;
+			}
+			/* fprintf(stderr, "ignore: %s", line); */
+			continue;
+		}
+		if (escaped) {
+			escaped--;
+			/* fprintf(stderr, "escaped: %s", line); */
+			continue;
+		}
+		strlcat(encoded, line, sizeof(encoded));
+	}
+	len = strlen(encoded);
+	if (((len % 4) == 3) &&
+	    (encoded[len-1] == '=') &&
+	    (encoded[len-2] == '=') &&
+	    (encoded[len-3] == '='))
+		encoded[len-3] = '\0';
+	blen = uudecode(encoded, blob, sizeof(blob));
+	if (blen < 0)
+		fatal("uudecode failed.");
+	if (*private)
+		*k = do_convert_private_ssh2_from_blob(blob, blen);
+	else if ((r = sshkey_from_blob(blob, blen, k)) != 0)
+		fatal("decode blob failed: %s", ssh_err(r));
+	fclose(fp);
+}
+
+static void
+do_convert_from_pkcs8(struct sshkey **k, int *private)
+{
+	EVP_PKEY *pubkey;
+	FILE *fp;
+
+	if ((fp = fopen(identity_file, "r")) == NULL)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+	if ((pubkey = PEM_read_PUBKEY(fp, NULL, NULL, NULL)) == NULL) {
+		fatal("%s: %s is not a recognised public key format", __func__,
+		    identity_file);
+	}
+	fclose(fp);
+	switch (EVP_PKEY_base_id(pubkey)) {
+	case EVP_PKEY_RSA:
+		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
+			fatal("sshkey_new failed");
+		(*k)->type = KEY_RSA;
+		(*k)->rsa = EVP_PKEY_get1_RSA(pubkey);
+		break;
+	case EVP_PKEY_DSA:
+		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
+			fatal("sshkey_new failed");
+		(*k)->type = KEY_DSA;
+		(*k)->dsa = EVP_PKEY_get1_DSA(pubkey);
+		break;
+#ifdef OPENSSL_HAS_ECC
+	case EVP_PKEY_EC:
+		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
+			fatal("sshkey_new failed");
+		(*k)->type = KEY_ECDSA;
+		(*k)->ecdsa = EVP_PKEY_get1_EC_KEY(pubkey);
+		(*k)->ecdsa_nid = sshkey_ecdsa_key_to_nid((*k)->ecdsa);
+		break;
+#endif
+	default:
+		fatal("%s: unsupported pubkey type %d", __func__,
+		    EVP_PKEY_base_id(pubkey));
+	}
+	EVP_PKEY_free(pubkey);
+	return;
+}
+
+static void
+do_convert_from_pem(struct sshkey **k, int *private)
+{
+	FILE *fp;
+	RSA *rsa;
+
+	if ((fp = fopen(identity_file, "r")) == NULL)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+	if ((rsa = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
+		if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
+			fatal("sshkey_new failed");
+		(*k)->type = KEY_RSA;
+		(*k)->rsa = rsa;
+		fclose(fp);
+		return;
+	}
+	fatal("%s: unrecognised raw private key format", __func__);
+}
+
+static void
+do_convert_from(struct passwd *pw)
+{
+	struct sshkey *k = NULL;
+	int r, private = 0, ok = 0;
+	struct stat st;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+
+	switch (convert_format) {
+	case FMT_RFC4716:
+		do_convert_from_ssh2(pw, &k, &private);
+		break;
+	case FMT_PKCS8:
+		do_convert_from_pkcs8(&k, &private);
+		break;
+	case FMT_PEM:
+		do_convert_from_pem(&k, &private);
+		break;
+	default:
+		fatal("%s: unknown key format %d", __func__, convert_format);
+	}
+
+	if (!private) {
+		if ((r = sshkey_write(k, stdout)) == 0)
+			ok = 1;
+		if (ok)
+			fprintf(stdout, "\n");
+	} else {
+		switch (k->type) {
+		case KEY_DSA:
+			ok = PEM_write_DSAPrivateKey(stdout, k->dsa, NULL,
+			    NULL, 0, NULL, NULL);
+			break;
+#ifdef OPENSSL_HAS_ECC
+		case KEY_ECDSA:
+			ok = PEM_write_ECPrivateKey(stdout, k->ecdsa, NULL,
+			    NULL, 0, NULL, NULL);
+			break;
+#endif
+		case KEY_RSA:
+			ok = PEM_write_RSAPrivateKey(stdout, k->rsa, NULL,
+			    NULL, 0, NULL, NULL);
+			break;
+		default:
+			fatal("%s: unsupported key type %s", __func__,
+			    sshkey_type(k));
+		}
+	}
+
+	if (!ok)
+		fatal("key write failed");
+	sshkey_free(k);
+	exit(0);
+}
+#endif
+
+static void
+do_print_public(struct passwd *pw)
+{
+	struct sshkey *prv;
+	struct stat st;
+	int r;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s", identity_file, strerror(errno));
+	prv = load_identity(identity_file);
+	if ((r = sshkey_write(prv, stdout)) != 0)
+		error("sshkey_write failed: %s", ssh_err(r));
+	sshkey_free(prv);
+	fprintf(stdout, "\n");
+	exit(0);
+}
+
+static void
+do_download(struct passwd *pw)
+{
+#ifdef ENABLE_PKCS11
+	struct sshkey **keys = NULL;
+	int i, nkeys;
+	enum sshkey_fp_rep rep;
+	int fptype;
+	char *fp, *ra;
+
+	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
+	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
+
+	pkcs11_init(0);
+	nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys);
+	if (nkeys <= 0)
+		fatal("cannot read public key from pkcs11");
+	for (i = 0; i < nkeys; i++) {
+		if (print_fingerprint) {
+			fp = sshkey_fingerprint(keys[i], fptype, rep);
+			ra = sshkey_fingerprint(keys[i], fingerprint_hash,
+			    SSH_FP_RANDOMART);
+			if (fp == NULL || ra == NULL)
+				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)
+				printf("%s\n", ra);
+			free(ra);
+			free(fp);
+		} else {
+			(void) sshkey_write(keys[i], stdout); /* XXX check */
+			fprintf(stdout, "\n");
+		}
+		sshkey_free(keys[i]);
+	}
+	free(keys);
+	pkcs11_terminate();
+	exit(0);
+#else
+	fatal("no pkcs11 support");
+#endif /* ENABLE_PKCS11 */
+}
+
+static struct sshkey *
+try_read_key(char **cpp)
+{
+	struct sshkey *ret;
+	int r;
+
+	if ((ret = sshkey_new(KEY_UNSPEC)) == NULL)
+		fatal("sshkey_new failed");
+	if ((r = sshkey_read(ret, cpp)) == 0)
+		return ret;
+	/* Not a key */
+	sshkey_free(ret);
+	return NULL;
+}
+
+static void
+fingerprint_one_key(const struct sshkey *public, const char *comment)
+{
+	char *fp = NULL, *ra = NULL;
+	enum sshkey_fp_rep rep;
+	int fptype;
+
+	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
+	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
+	fp = sshkey_fingerprint(public, fptype, rep);
+	ra = sshkey_fingerprint(public, fingerprint_hash, SSH_FP_RANDOMART);
+	if (fp == NULL || ra == NULL)
+		fatal("%s: sshkey_fingerprint failed", __func__);
+	mprintf("%u %s %s (%s)\n", sshkey_size(public), fp,
+	    comment ? comment : "no comment", sshkey_type(public));
+	if (log_level >= SYSLOG_LEVEL_VERBOSE)
+		printf("%s\n", ra);
+	free(ra);
+	free(fp);
+}
+
+static void
+fingerprint_private(const char *path)
+{
+	struct stat st;
+	char *comment = NULL;
+	struct sshkey *public = NULL;
+	int r;
+
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s", path, strerror(errno));
+	if ((r = sshkey_load_public(path, &public, &comment)) != 0) {
+		debug("load public \"%s\": %s", path, ssh_err(r));
+		if ((r = sshkey_load_private(path, NULL,
+		    &public, &comment)) != 0) {
+			debug("load private \"%s\": %s", path, ssh_err(r));
+			fatal("%s is not a key file.", path);
+		}
+	}
+
+	fingerprint_one_key(public, comment);
+	sshkey_free(public);
+	free(comment);
+}
+
+static void
+do_fingerprint(struct passwd *pw)
+{
+	FILE *f;
+	struct sshkey *public = NULL;
+	char *comment = NULL, *cp, *ep, *line = NULL;
+	size_t linesize = 0;
+	int i, invalid = 1;
+	const char *path;
+	u_long lnum = 0;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	path = identity_file;
+
+	if (strcmp(identity_file, "-") == 0) {
+		f = stdin;
+		path = "(stdin)";
+	} else if ((f = fopen(path, "r")) == NULL)
+		fatal("%s: %s: %s", __progname, path, strerror(errno));
+
+	while (getline(&line, &linesize, f) != -1) {
+		lnum++;
+		cp = line;
+		cp[strcspn(cp, "\n")] = '\0';
+		/* Trim leading space and comments */
+		cp = line + strspn(line, " \t");
+		if (*cp == '#' || *cp == '\0')
+			continue;
+
+		/*
+		 * Input may be plain keys, private keys, authorized_keys
+		 * or known_hosts.
+		 */
+
+		/*
+		 * Try private keys first. Assume a key is private if
+		 * "SSH PRIVATE KEY" appears on the first line and we're
+		 * not reading from stdin (XXX support private keys on stdin).
+		 */
+		if (lnum == 1 && strcmp(identity_file, "-") != 0 &&
+		    strstr(cp, "PRIVATE KEY") != NULL) {
+			free(line);
+			fclose(f);
+			fingerprint_private(path);
+			exit(0);
+		}
+
+		/*
+		 * If it's not a private key, then this must be prepared to
+		 * accept a public key prefixed with a hostname or options.
+		 * Try a bare key first, otherwise skip the leading stuff.
+		 */
+		if ((public = try_read_key(&cp)) == NULL) {
+			i = strtol(cp, &ep, 10);
+			if (i == 0 || ep == NULL ||
+			    (*ep != ' ' && *ep != '\t')) {
+				int quoted = 0;
+
+				comment = cp;
+				for (; *cp && (quoted || (*cp != ' ' &&
+				    *cp != '\t')); cp++) {
+					if (*cp == '\\' && cp[1] == '"')
+						cp++;	/* Skip both */
+					else if (*cp == '"')
+						quoted = !quoted;
+				}
+				if (!*cp)
+					continue;
+				*cp++ = '\0';
+			}
+		}
+		/* Retry after parsing leading hostname/key options */
+		if (public == NULL && (public = try_read_key(&cp)) == NULL) {
+			debug("%s:%lu: not a public key", path, lnum);
+			continue;
+		}
+
+		/* Find trailing comment, if any */
+		for (; *cp == ' ' || *cp == '\t'; cp++)
+			;
+		if (*cp != '\0' && *cp != '#')
+			comment = cp;
+
+		fingerprint_one_key(public, comment);
+		sshkey_free(public);
+		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);
+	exit(0);
+}
+
+static void
+do_gen_all_hostkeys(struct passwd *pw)
+{
+	struct {
+		char *key_type;
+		char *key_type_display;
+		char *path;
+	} key_types[] = {
+#ifdef WITH_OPENSSL
+		{ "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
+		{ "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
+#ifdef OPENSSL_HAS_ECC
+		{ "ecdsa", "ECDSA",_PATH_HOST_ECDSA_KEY_FILE },
+#endif /* OPENSSL_HAS_ECC */
+#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 }
+	};
+
+	int first = 0;
+	struct stat st;
+	struct sshkey *private, *public;
+	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++) {
+		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));
+			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);
+		}
+		printf("%s ", key_types[i].key_type_display);
+		fflush(stdout);
+		type = sshkey_type_from_name(key_types[i].key_type);
+		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("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, prv_tmp, "",
+		    comment, use_new_format, new_format_cipher, rounds)) != 0) {
+			error("Saving key \"%s\" failed: %s",
+			    prv_tmp, ssh_err(r));
+			goto failnext;
+		}
+		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: %s", pub_tmp, strerror(errno));
+			close(fd);
+			goto failnext;
+		}
+		if ((r = sshkey_write(public, f)) != 0) {
+			error("write key failed: %s", ssh_err(r));
+			fclose(f);
+			goto failnext;
+		}
+		fprintf(f, " %s\n", comment);
+		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");
+}
+
+struct known_hosts_ctx {
+	const char *host;	/* Hostname searched for in find/delete case */
+	FILE *out;		/* Output file, stdout for find_hosts case */
+	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 */
+};
+
+static int
+known_hosts_hash(struct hostkey_foreach_line *l, void *_ctx)
+{
+	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:
+	case HKF_STATUS_MATCHED:
+		/*
+		 * Don't hash hosts already already hashed, with wildcard
+		 * characters or a CA/revocation marker.
+		 */
+		if (was_hashed || has_wild || l->marker != MRK_NONE) {
+			fprintf(ctx->out, "%s\n", l->line);
+			if (has_wild && !find_host) {
+				logit("%s:%lu: ignoring host name "
+				    "with wildcard: %.64s", l->path,
+				    l->linenum, l->hosts);
+			}
+			return 0;
+		}
+		/*
+		 * Split any comma-separated hostnames from the host list,
+		 * hash and store separately.
+		 */
+		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);
+			ctx->has_unhashed = 1;
+		}
+		free(ohosts);
+		return 0;
+	case HKF_STATUS_INVALID:
+		/* Retain invalid lines, but mark file as invalid. */
+		ctx->invalid = 1;
+		logit("%s:%lu: invalid line", l->path, l->linenum);
+		/* FALLTHROUGH */
+	default:
+		fprintf(ctx->out, "%s\n", l->line);
+		return 0;
+	}
+	/* NOTREACHED */
+	return -1;
+}
+
+static int
+known_hosts_find_delete(struct hostkey_foreach_line *l, void *_ctx)
+{
+	struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
+	enum sshkey_fp_rep rep;
+	int fptype;
+	char *fp;
+
+	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
+	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
+
+	if (l->status == HKF_STATUS_MATCHED) {
+		if (delete_host) {
+			if (l->marker != MRK_NONE) {
+				/* Don't remove CA and revocation lines */
+				fprintf(ctx->out, "%s\n", l->line);
+			} else {
+				/*
+				 * Hostname matches and has no CA/revoke
+				 * marker, delete it by *not* writing the
+				 * line to ctx->out.
+				 */
+				ctx->found_key = 1;
+				if (!quiet)
+					printf("# Host %s found: line %lu\n",
+					    ctx->host, l->linenum);
+			}
+			return 0;
+		} else if (find_host) {
+			ctx->found_key = 1;
+			if (!quiet) {
+				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)
+				known_hosts_hash(l, ctx);
+			else if (print_fingerprint) {
+				fp = sshkey_fingerprint(l->key, fptype, rep);
+				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) {
+		/* Retain non-matching hosts when deleting */
+		if (l->status == HKF_STATUS_INVALID) {
+			ctx->invalid = 1;
+			logit("%s:%lu: invalid line", l->path, l->linenum);
+		}
+		fprintf(ctx->out, "%s\n", l->line);
+	}
+	return 0;
+}
+
+static void
+do_known_hosts(struct passwd *pw, const char *name)
+{
+	char *cp, tmp[PATH_MAX], old[PATH_MAX];
+	int r, fd, oerrno, inplace = 0;
+	struct known_hosts_ctx ctx;
+	u_int foreach_options;
+
+	if (!have_identity) {
+		cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
+		if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
+		    sizeof(identity_file))
+			fatal("Specified known hosts path too long");
+		free(cp);
+		have_identity = 1;
+	}
+
+	memset(&ctx, 0, sizeof(ctx));
+	ctx.out = stdout;
+	ctx.host = name;
+
+	/*
+	 * Find hosts goes to stdout, hash and deletions happen in-place
+	 * A corner case is ssh-keygen -HF foo, which should go to stdout
+	 */
+	if (!find_host && (hash_hosts || delete_host)) {
+		if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
+		    strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
+		    strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
+		    strlcat(old, ".old", sizeof(old)) >= sizeof(old))
+			fatal("known_hosts path too long");
+		umask(077);
+		if ((fd = mkstemp(tmp)) == -1)
+			fatal("mkstemp: %s", strerror(errno));
+		if ((ctx.out = fdopen(fd, "w")) == NULL) {
+			oerrno = errno;
+			unlink(tmp);
+			fatal("fdopen: %s", strerror(oerrno));
+		}
+		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, (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));
+	}
+
+	if (inplace)
+		fclose(ctx.out);
+
+	if (ctx.invalid) {
+		error("%s is not a valid known_hosts file.", identity_file);
+		if (inplace) {
+			error("Not replacing existing known_hosts "
+			    "file because of errors");
+			unlink(tmp);
+		}
+		exit(1);
+	} else if (delete_host && !ctx.found_key) {
+		logit("Host %s not found in %s", name, identity_file);
+		if (inplace)
+			unlink(tmp);
+	} else if (inplace) {
+		/* Backup existing file */
+		if (unlink(old) == -1 && errno != ENOENT)
+			fatal("unlink %.100s: %s", old, strerror(errno));
+		if (link(identity_file, old) == -1)
+			fatal("link %.100s to %.100s: %s", identity_file, old,
+			    strerror(errno));
+		/* Move new one into place */
+		if (rename(tmp, identity_file) == -1) {
+			error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
+			    strerror(errno));
+			unlink(tmp);
+			unlink(old);
+			exit(1);
+		}
+
+		printf("%s updated.\n", identity_file);
+		printf("Original contents retained as %s\n", old);
+		if (ctx.has_unhashed) {
+			logit("WARNING: %s contains unhashed entries", old);
+			logit("Delete this file to ensure privacy "
+			    "of hostnames");
+		}
+	}
+
+	exit (find_host && !ctx.found_key);
+}
+
+/*
+ * Perform changing a passphrase.  The argument is the passwd structure
+ * for the current user.
+ */
+static void
+do_change_passphrase(struct passwd *pw)
+{
+	char *comment;
+	char *old_passphrase, *passphrase1, *passphrase2;
+	struct stat st;
+	struct sshkey *private;
+	int r;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s", identity_file, strerror(errno));
+	/* Try to load the file with empty passphrase. */
+	r = sshkey_load_private(identity_file, "", &private, &comment);
+	if (r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
+		if (identity_passphrase)
+			old_passphrase = xstrdup(identity_passphrase);
+		else
+			old_passphrase =
+			    read_passphrase("Enter old passphrase: ",
+			    RP_ALLOW_STDIN);
+		r = sshkey_load_private(identity_file, old_passphrase,
+		    &private, &comment);
+		explicit_bzero(old_passphrase, strlen(old_passphrase));
+		free(old_passphrase);
+		if (r != 0)
+			goto badkey;
+	} else if (r != 0) {
+ badkey:
+		fatal("Failed to load key %s: %s", identity_file, ssh_err(r));
+	}
+	if (comment)
+		mprintf("Key has comment '%s'\n", comment);
+
+	/* Ask the new passphrase (twice). */
+	if (identity_new_passphrase) {
+		passphrase1 = xstrdup(identity_new_passphrase);
+		passphrase2 = NULL;
+	} else {
+		passphrase1 =
+			read_passphrase("Enter new passphrase (empty for no "
+			    "passphrase): ", RP_ALLOW_STDIN);
+		passphrase2 = read_passphrase("Enter same passphrase again: ",
+		    RP_ALLOW_STDIN);
+
+		/* Verify that they are the same. */
+		if (strcmp(passphrase1, passphrase2) != 0) {
+			explicit_bzero(passphrase1, strlen(passphrase1));
+			explicit_bzero(passphrase2, strlen(passphrase2));
+			free(passphrase1);
+			free(passphrase2);
+			printf("Pass phrases do not match.  Try again.\n");
+			exit(1);
+		}
+		/* Destroy the other copy. */
+		explicit_bzero(passphrase2, strlen(passphrase2));
+		free(passphrase2);
+	}
+
+	/* Save the file using the new passphrase. */
+	if ((r = sshkey_save_private(private, identity_file, passphrase1,
+	    comment, use_new_format, new_format_cipher, rounds)) != 0) {
+		error("Saving key \"%s\" failed: %s.",
+		    identity_file, ssh_err(r));
+		explicit_bzero(passphrase1, strlen(passphrase1));
+		free(passphrase1);
+		sshkey_free(private);
+		free(comment);
+		exit(1);
+	}
+	/* Destroy the passphrase and the copy of the key in memory. */
+	explicit_bzero(passphrase1, strlen(passphrase1));
+	free(passphrase1);
+	sshkey_free(private);		 /* Destroys contents */
+	free(comment);
+
+	printf("Your identification has been saved with the new passphrase.\n");
+	exit(0);
+}
+
+/*
+ * Print the SSHFP RR.
+ */
+static int
+do_print_resource_record(struct passwd *pw, char *fname, char *hname)
+{
+	struct sshkey *public;
+	char *comment = NULL;
+	struct stat st;
+	int r;
+
+	if (fname == NULL)
+		fatal("%s: no filename", __func__);
+	if (stat(fname, &st) < 0) {
+		if (errno == ENOENT)
+			return 0;
+		fatal("%s: %s", fname, strerror(errno));
+	}
+	if ((r = sshkey_load_public(fname, &public, &comment)) != 0)
+		fatal("Failed to read v2 public key from \"%s\": %s.",
+		    fname, ssh_err(r));
+	export_dns_rr(hname, public, stdout, print_generic);
+	sshkey_free(public);
+	free(comment);
+	return 1;
+}
+
+/*
+ * Change the comment of a private key file.
+ */
+static void
+do_change_comment(struct passwd *pw)
+{
+	char new_comment[1024], *comment, *passphrase;
+	struct sshkey *private;
+	struct sshkey *public;
+	struct stat st;
+	FILE *f;
+	int r, fd;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (stat(identity_file, &st) < 0)
+		fatal("%s: %s", identity_file, strerror(errno));
+	if ((r = sshkey_load_private(identity_file, "",
+	    &private, &comment)) == 0)
+		passphrase = xstrdup("");
+	else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
+		fatal("Cannot load private key \"%s\": %s.",
+		    identity_file, ssh_err(r));
+	else {
+		if (identity_passphrase)
+			passphrase = xstrdup(identity_passphrase);
+		else if (identity_new_passphrase)
+			passphrase = xstrdup(identity_new_passphrase);
+		else
+			passphrase = read_passphrase("Enter passphrase: ",
+			    RP_ALLOW_STDIN);
+		/* Try to load using the passphrase. */
+		if ((r = sshkey_load_private(identity_file, passphrase,
+		    &private, &comment)) != 0) {
+			explicit_bzero(passphrase, strlen(passphrase));
+			free(passphrase);
+			fatal("Cannot load private key \"%s\": %s.",
+			    identity_file, ssh_err(r));
+		}
+	}
+
+	if (private->type != KEY_ED25519 && private->type != KEY_XMSS &&
+	    !use_new_format) {
+		error("Comments are only supported for keys stored in "
+		    "the new format (-o).");
+		explicit_bzero(passphrase, strlen(passphrase));
+		sshkey_free(private);
+		exit(1);
+	}
+	if (comment)
+		printf("Key now has comment '%s'\n", comment);
+	else
+		printf("Key now has no comment\n");
+
+	if (identity_comment) {
+		strlcpy(new_comment, identity_comment, sizeof(new_comment));
+	} else {
+		printf("Enter new comment: ");
+		fflush(stdout);
+		if (!fgets(new_comment, sizeof(new_comment), stdin)) {
+			explicit_bzero(passphrase, strlen(passphrase));
+			sshkey_free(private);
+			exit(1);
+		}
+		new_comment[strcspn(new_comment, "\n")] = '\0';
+	}
+
+	/* Save the file using the new passphrase. */
+	if ((r = sshkey_save_private(private, identity_file, passphrase,
+	    new_comment, use_new_format, new_format_cipher, rounds)) != 0) {
+		error("Saving key \"%s\" failed: %s",
+		    identity_file, ssh_err(r));
+		explicit_bzero(passphrase, strlen(passphrase));
+		free(passphrase);
+		sshkey_free(private);
+		free(comment);
+		exit(1);
+	}
+	explicit_bzero(passphrase, strlen(passphrase));
+	free(passphrase);
+	if ((r = sshkey_from_private(private, &public)) != 0)
+		fatal("sshkey_from_private failed: %s", ssh_err(r));
+	sshkey_free(private);
+
+	strlcat(identity_file, ".pub", sizeof(identity_file));
+	fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd == -1)
+		fatal("Could not save your public key in %s", identity_file);
+	f = fdopen(fd, "w");
+	if (f == NULL)
+		fatal("fdopen %s failed: %s", identity_file, strerror(errno));
+	if ((r = sshkey_write(public, f)) != 0)
+		fatal("write key failed: %s", ssh_err(r));
+	sshkey_free(public);
+	fprintf(f, " %s\n", new_comment);
+	fclose(f);
+
+	free(comment);
+
+	printf("The comment in your key file has been changed.\n");
+	exit(0);
+}
+
+static void
+add_flag_option(struct sshbuf *c, const char *name)
+{
+	int r;
+
+	debug3("%s: %s", __func__, name);
+	if ((r = sshbuf_put_cstring(c, name)) != 0 ||
+	    (r = sshbuf_put_string(c, NULL, 0)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+}
+
+static void
+add_string_option(struct sshbuf *c, const char *name, const char *value)
+{
+	struct sshbuf *b;
+	int r;
+
+	debug3("%s: %s=%s", __func__, name, value);
+	if ((b = sshbuf_new()) == NULL)
+		fatal("%s: sshbuf_new failed", __func__);
+	if ((r = sshbuf_put_cstring(b, value)) != 0 ||
+	    (r = sshbuf_put_cstring(c, name)) != 0 ||
+	    (r = sshbuf_put_stringb(c, b)) != 0)
+		fatal("%s: buffer error: %s", __func__, ssh_err(r));
+
+	sshbuf_free(b);
+}
+
+#define OPTIONS_CRITICAL	1
+#define OPTIONS_EXTENSIONS	2
+static void
+prepare_options_buf(struct sshbuf *c, int which)
+{
+	size_t i;
+
+	sshbuf_reset(c);
+	if ((which & OPTIONS_CRITICAL) != 0 &&
+	    certflags_command != NULL)
+		add_string_option(c, "force-command", certflags_command);
+	if ((which & OPTIONS_EXTENSIONS) != 0 &&
+	    (certflags_flags & CERTOPT_X_FWD) != 0)
+		add_flag_option(c, "permit-X11-forwarding");
+	if ((which & OPTIONS_EXTENSIONS) != 0 &&
+	    (certflags_flags & CERTOPT_AGENT_FWD) != 0)
+		add_flag_option(c, "permit-agent-forwarding");
+	if ((which & OPTIONS_EXTENSIONS) != 0 &&
+	    (certflags_flags & CERTOPT_PORT_FWD) != 0)
+		add_flag_option(c, "permit-port-forwarding");
+	if ((which & OPTIONS_EXTENSIONS) != 0 &&
+	    (certflags_flags & CERTOPT_PTY) != 0)
+		add_flag_option(c, "permit-pty");
+	if ((which & OPTIONS_EXTENSIONS) != 0 &&
+	    (certflags_flags & CERTOPT_USER_RC) != 0)
+		add_flag_option(c, "permit-user-rc");
+	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 *
+load_pkcs11_key(char *path)
+{
+#ifdef ENABLE_PKCS11
+	struct sshkey **keys = NULL, *public, *private = NULL;
+	int r, i, nkeys;
+
+	if ((r = sshkey_load_public(path, &public, NULL)) != 0)
+		fatal("Couldn't load CA public key \"%s\": %s",
+		    path, ssh_err(r));
+
+	nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase, &keys);
+	debug3("%s: %d keys", __func__, nkeys);
+	if (nkeys <= 0)
+		fatal("cannot read public key from pkcs11");
+	for (i = 0; i < nkeys; i++) {
+		if (sshkey_equal_public(public, keys[i])) {
+			private = keys[i];
+			continue;
+		}
+		sshkey_free(keys[i]);
+	}
+	free(keys);
+	sshkey_free(public);
+	return private;
+#else
+	fatal("no pkcs11 support");
+#endif /* ENABLE_PKCS11 */
+}
+
+/* Signer for sshkey_certify_custom that uses the agent */
+static int
+agent_signer(const 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)
+{
+	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 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;
+		if (cert_principals != NULL) {
+			otmp = tmp = xstrdup(cert_principals);
+			plist = NULL;
+			for (; (cp = strsep(&tmp, ",")) != NULL; n++) {
+				plist = xreallocarray(plist, n + 1, sizeof(*plist));
+				if (*(plist[n] = xstrdup(cp)) == '\0')
+					fatal("Empty principal name");
+			}
+			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_XMSS)
+			fatal("%s: key \"%s\" type %s cannot be certified",
+			    __func__, tmp, sshkey_type(public));
+
+		/* Prepare certificate to sign */
+		if ((r = sshkey_to_certified(public)) != 0)
+			fatal("Could not upgrade key %s to certificate: %s",
+			    tmp, ssh_err(r));
+		public->cert->type = cert_key_type;
+		public->cert->serial = (u_int64_t)cert_serial;
+		public->cert->key_id = xstrdup(cert_key_id);
+		public->cert->nprincipals = n;
+		public->cert->principals = plist;
+		public->cert->valid_after = cert_valid_from;
+		public->cert->valid_before = cert_valid_to;
+		prepare_options_buf(public->cert->critical, OPTIONS_CRITICAL);
+		prepare_options_buf(public->cert->extensions,
+		    OPTIONS_EXTENSIONS);
+		if ((r = sshkey_from_private(ca,
+		    &public->cert->signature_key)) != 0)
+			fatal("sshkey_from_private (ca key): %s", ssh_err(r));
+
+		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';
+		xasprintf(&out, "%s-cert.pub", tmp);
+		free(tmp);
+
+		if ((fd = open(out, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
+			fatal("Could not open \"%s\" for writing: %s", out,
+			    strerror(errno));
+		if ((f = fdopen(fd, "w")) == NULL)
+			fatal("%s: fdopen: %s", __func__, strerror(errno));
+		if ((r = sshkey_write(public, f)) != 0)
+			fatal("Could not write certified key to %s: %s",
+			    out, ssh_err(r));
+		fprintf(f, " %s\n", comment);
+		fclose(f);
+
+		if (!quiet) {
+			sshkey_format_cert_validity(public->cert,
+			    valid, sizeof(valid));
+			logit("Signed %s key %s: id \"%s\" serial %llu%s%s "
+			    "valid %s", sshkey_cert_type(public),
+			    out, public->cert->key_id,
+			    (unsigned long long)public->cert->serial,
+			    cert_principals != NULL ? " for " : "",
+			    cert_principals != NULL ? cert_principals : "",
+			    valid);
+		}
+
+		sshkey_free(public);
+		free(out);
+	}
+#ifdef ENABLE_PKCS11
+	pkcs11_terminate();
+#endif
+	exit(0);
+}
+
+static u_int64_t
+parse_relative_time(const char *s, time_t now)
+{
+	int64_t mul, secs;
+
+	mul = *s == '-' ? -1 : 1;
+
+	if ((secs = convtime(s + 1)) == -1)
+		fatal("Invalid relative certificate time %s", s);
+	if (mul == -1 && secs > now)
+		fatal("Certificate time %s cannot be represented", s);
+	return now + (u_int64_t)(secs * mul);
+}
+
+static void
+parse_cert_times(char *timespec)
+{
+	char *from, *to;
+	time_t now = time(NULL);
+	int64_t secs;
+
+	/* +timespec relative to now */
+	if (*timespec == '+' && strchr(timespec, ':') == NULL) {
+		if ((secs = convtime(timespec + 1)) == -1)
+			fatal("Invalid relative certificate life %s", timespec);
+		cert_valid_to = now + secs;
+		/*
+		 * Backdate certificate one minute to avoid problems on hosts
+		 * with poorly-synchronised clocks.
+		 */
+		cert_valid_from = ((now - 59)/ 60) * 60;
+		return;
+	}
+
+	/*
+	 * from:to, where
+	 * from := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "always"
+	 *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS | "forever"
+	 */
+	from = xstrdup(timespec);
+	to = strchr(from, ':');
+	if (to == NULL || from == to || *(to + 1) == '\0')
+		fatal("Invalid certificate life specification %s", timespec);
+	*to++ = '\0';
+
+	if (*from == '-' || *from == '+')
+		cert_valid_from = parse_relative_time(from, now);
+	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 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");
+	free(from);
+}
+
+static void
+add_cert_option(char *opt)
+{
+	char *val, *cp;
+	int iscrit = 0;
+
+	if (strcasecmp(opt, "clear") == 0)
+		certflags_flags = 0;
+	else if (strcasecmp(opt, "no-x11-forwarding") == 0)
+		certflags_flags &= ~CERTOPT_X_FWD;
+	else if (strcasecmp(opt, "permit-x11-forwarding") == 0)
+		certflags_flags |= CERTOPT_X_FWD;
+	else if (strcasecmp(opt, "no-agent-forwarding") == 0)
+		certflags_flags &= ~CERTOPT_AGENT_FWD;
+	else if (strcasecmp(opt, "permit-agent-forwarding") == 0)
+		certflags_flags |= CERTOPT_AGENT_FWD;
+	else if (strcasecmp(opt, "no-port-forwarding") == 0)
+		certflags_flags &= ~CERTOPT_PORT_FWD;
+	else if (strcasecmp(opt, "permit-port-forwarding") == 0)
+		certflags_flags |= CERTOPT_PORT_FWD;
+	else if (strcasecmp(opt, "no-pty") == 0)
+		certflags_flags &= ~CERTOPT_PTY;
+	else if (strcasecmp(opt, "permit-pty") == 0)
+		certflags_flags |= CERTOPT_PTY;
+	else if (strcasecmp(opt, "no-user-rc") == 0)
+		certflags_flags &= ~CERTOPT_USER_RC;
+	else if (strcasecmp(opt, "permit-user-rc") == 0)
+		certflags_flags |= CERTOPT_USER_RC;
+	else if (strncasecmp(opt, "force-command=", 14) == 0) {
+		val = opt + 14;
+		if (*val == '\0')
+			fatal("Empty force-command option");
+		if (certflags_command != NULL)
+			fatal("force-command already specified");
+		certflags_command = xstrdup(val);
+	} else if (strncasecmp(opt, "source-address=", 15) == 0) {
+		val = opt + 15;
+		if (*val == '\0')
+			fatal("Empty source-address option");
+		if (certflags_src_addr != NULL)
+			fatal("source-address already specified");
+		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);
+}
+
+static void
+show_options(struct sshbuf *optbuf, int in_critical)
+{
+	char *name, *arg;
+	struct sshbuf *options, *option = NULL;
+	int r;
+
+	if ((options = sshbuf_fromb(optbuf)) == NULL)
+		fatal("%s: sshbuf_fromb failed", __func__);
+	while (sshbuf_len(options) != 0) {
+		sshbuf_free(option);
+		option = NULL;
+		if ((r = sshbuf_get_cstring(options, &name, NULL)) != 0 ||
+		    (r = sshbuf_froms(options, &option)) != 0)
+			fatal("%s: buffer error: %s", __func__, ssh_err(r));
+		printf("                %s", name);
+		if (!in_critical &&
+		    (strcmp(name, "permit-X11-forwarding") == 0 ||
+		    strcmp(name, "permit-agent-forwarding") == 0 ||
+		    strcmp(name, "permit-port-forwarding") == 0 ||
+		    strcmp(name, "permit-pty") == 0 ||
+		    strcmp(name, "permit-user-rc") == 0))
+			printf("\n");
+		else if (in_critical &&
+		    (strcmp(name, "force-command") == 0 ||
+		    strcmp(name, "source-address") == 0)) {
+			if ((r = sshbuf_get_cstring(option, &arg, NULL)) != 0)
+				fatal("%s: buffer error: %s",
+				    __func__, ssh_err(r));
+			printf(" %s\n", arg);
+			free(arg);
+		} else {
+			printf(" UNKNOWN OPTION (len %zu)\n",
+			    sshbuf_len(option));
+			sshbuf_reset(option);
+		}
+		free(name);
+		if (sshbuf_len(option) != 0)
+			fatal("Option corrupt: extra data at end");
+	}
+	sshbuf_free(option);
+	sshbuf_free(options);
+}
+
+static void
+print_cert(struct sshkey *key)
+{
+	char valid[64], *key_fp, *ca_fp;
+	u_int i;
+
+	key_fp = sshkey_fingerprint(key, fingerprint_hash, SSH_FP_DEFAULT);
+	ca_fp = sshkey_fingerprint(key->cert->signature_key,
+	    fingerprint_hash, SSH_FP_DEFAULT);
+	if (key_fp == NULL || ca_fp == NULL)
+		fatal("%s: sshkey_fingerprint fail", __func__);
+	sshkey_format_cert_validity(key->cert, valid, sizeof(valid));
+
+	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("        Key ID: \"%s\"\n", key->cert->key_id);
+	printf("        Serial: %llu\n", (unsigned long long)key->cert->serial);
+	printf("        Valid: %s\n", valid);
+	printf("        Principals: ");
+	if (key->cert->nprincipals == 0)
+		printf("(none)\n");
+	else {
+		for (i = 0; i < key->cert->nprincipals; i++)
+			printf("\n                %s",
+			    key->cert->principals[i]);
+		printf("\n");
+	}
+	printf("        Critical Options: ");
+	if (sshbuf_len(key->cert->critical) == 0)
+		printf("(none)\n");
+	else {
+		printf("\n");
+		show_options(key->cert->critical, 1);
+	}
+	printf("        Extensions: ");
+	if (sshbuf_len(key->cert->extensions) == 0)
+		printf("(none)\n");
+	else {
+		printf("\n");
+		show_options(key->cert->extensions, 0);
+	}
+}
+
+static void
+do_show_cert(struct passwd *pw)
+{
+	struct sshkey *key = NULL;
+	struct stat st;
+	int r, is_stdin = 0, ok = 0;
+	FILE *f;
+	char *cp, *line = NULL;
+	const char *path;
+	size_t linesize = 0;
+	u_long lnum = 0;
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which the key is");
+	if (strcmp(identity_file, "-") != 0 && stat(identity_file, &st) < 0)
+		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+
+	path = identity_file;
+	if (strcmp(path, "-") == 0) {
+		f = stdin;
+		path = "(stdin)";
+		is_stdin = 1;
+	} else if ((f = fopen(identity_file, "r")) == NULL)
+		fatal("fopen %s: %s", identity_file, strerror(errno));
+
+	while (getline(&line, &linesize, f) != -1) {
+		lnum++;
+		sshkey_free(key);
+		key = NULL;
+		/* Trim leading space and comments */
+		cp = line + strspn(line, " \t");
+		if (*cp == '#' || *cp == '\0')
+			continue;
+		if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
+			fatal("sshkey_new");
+		if ((r = sshkey_read(key, &cp)) != 0) {
+			error("%s:%lu: invalid key: %s", path,
+			    lnum, ssh_err(r));
+			continue;
+		}
+		if (!sshkey_is_cert(key)) {
+			error("%s:%lu is not a certificate", path, lnum);
+			continue;
+		}
+		ok = 1;
+		if (!is_stdin && lnum == 1)
+			printf("%s:\n", path);
+		else
+			printf("%s:%lu:\n", path, lnum);
+		print_cert(key);
+	}
+	free(line);
+	sshkey_free(key);
+	fclose(f);
+	exit(ok ? 0 : 1);
+}
+
+static void
+load_krl(const char *path, struct ssh_krl **krlp)
+{
+	struct sshbuf *krlbuf;
+	int r, fd;
+
+	if ((krlbuf = sshbuf_new()) == NULL)
+		fatal("sshbuf_new failed");
+	if ((fd = open(path, O_RDONLY)) == -1)
+		fatal("open %s: %s", path, strerror(errno));
+	if ((r = sshkey_load_file(fd, krlbuf)) != 0)
+		fatal("Unable to load KRL: %s", ssh_err(r));
+	close(fd);
+	/* XXX check sigs */
+	if ((r = ssh_krl_from_blob(krlbuf, krlp, NULL, 0)) != 0 ||
+	    *krlp == NULL)
+		fatal("Invalid KRL file: %s", ssh_err(r));
+	sshbuf_free(krlbuf);
+}
+
+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 = NULL;
+	u_char *blob = NULL;
+	size_t blen = 0, linesize = 0;
+	unsigned long long serial, serial2;
+	int i, was_explicit_key, was_sha1, was_sha256, was_hash, r;
+	FILE *krl_spec;
+
+	path = tilde_expand_filename(file, pw->pw_uid);
+	if (strcmp(path, "-") == 0) {
+		krl_spec = stdin;
+		free(path);
+		path = xstrdup("(standard input)");
+	} else if ((krl_spec = fopen(path, "r")) == NULL)
+		fatal("fopen %s: %s", path, strerror(errno));
+
+	if (!quiet)
+		printf("Revoking from %s\n", path);
+	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++) {
+			if (cp[i] == '#' || cp[i] == '\n') {
+				cp[i] = '\0';
+				break;
+			}
+			if (cp[i] == ' ' || cp[i] == '\t') {
+				/* Remember the start of a span of whitespace */
+				if (r == -1)
+					r = i;
+			} else
+				r = -1;
+		}
+		if (r != -1)
+			cp[r] = '\0';
+		if (*cp == '\0')
+			continue;
+		if (strncasecmp(cp, "serial:", 7) == 0) {
+			if (ca == NULL && !wild_ca) {
+				fatal("revoking certificates by serial number "
+				    "requires specification of a CA key");
+			}
+			cp += 7;
+			cp = cp + strspn(cp, " \t");
+			errno = 0;
+			serial = strtoull(cp, &ep, 0);
+			if (*cp == '\0' || (*ep != '\0' && *ep != '-'))
+				fatal("%s:%lu: invalid serial \"%s\"",
+				    path, lnum, cp);
+			if (errno == ERANGE && serial == ULLONG_MAX)
+				fatal("%s:%lu: serial out of range",
+				    path, lnum);
+			serial2 = serial;
+			if (*ep == '-') {
+				cp = ep + 1;
+				errno = 0;
+				serial2 = strtoull(cp, &ep, 0);
+				if (*cp == '\0' || *ep != '\0')
+					fatal("%s:%lu: invalid serial \"%s\"",
+					    path, lnum, cp);
+				if (errno == ERANGE && serial2 == ULLONG_MAX)
+					fatal("%s:%lu: serial out of range",
+					    path, lnum);
+				if (serial2 <= serial)
+					fatal("%s:%lu: invalid serial range "
+					    "%llu:%llu", path, lnum,
+					    (unsigned long long)serial,
+					    (unsigned long long)serial2);
+			}
+			if (ssh_krl_revoke_cert_by_serial_range(krl,
+			    ca, serial, serial2) != 0) {
+				fatal("%s: revoke serial failed",
+				    __func__);
+			}
+		} else if (strncasecmp(cp, "id:", 3) == 0) {
+			if (ca == NULL && !wild_ca) {
+				fatal("revoking certificates by key ID "
+				    "requires specification of a CA key");
+			}
+			cp += 3;
+			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;
+				cp = cp + strspn(cp, " \t");
+				was_explicit_key = 1;
+			} else if (strncasecmp(cp, "sha1:", 5) == 0) {
+				cp += 5;
+				cp = cp + strspn(cp, " \t");
+				was_sha1 = 1;
+			} 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("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) {
+				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)
+{
+	struct ssh_krl *krl;
+	struct stat sb;
+	struct sshkey *ca = NULL;
+	int fd, i, r, wild_ca = 0;
+	char *tmp;
+	struct sshbuf *kbuf;
+
+	if (*identity_file == '\0')
+		fatal("KRL generation requires an output file");
+	if (stat(identity_file, &sb) == -1) {
+		if (errno != ENOENT)
+			fatal("Cannot access KRL \"%s\": %s",
+			    identity_file, strerror(errno));
+		if (updating)
+			fatal("KRL \"%s\" does not exist", identity_file);
+	}
+	if (ca_key_path != NULL) {
+		if (strcasecmp(ca_key_path, "none") == 0)
+			wild_ca = 1;
+		else {
+			tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
+			if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
+				fatal("Cannot load CA public key %s: %s",
+				    tmp, ssh_err(r));
+			free(tmp);
+		}
+	}
+
+	if (updating)
+		load_krl(identity_file, &krl);
+	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);
+
+	for (i = 0; i < argc; i++)
+		update_krl_from_file(pw, argv[i], wild_ca, ca, krl);
+
+	if ((kbuf = sshbuf_new()) == NULL)
+		fatal("sshbuf_new failed");
+	if (ssh_krl_to_blob(krl, kbuf, NULL, 0) != 0)
+		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, sshbuf_mutable_ptr(kbuf), sshbuf_len(kbuf)) !=
+	    sshbuf_len(kbuf))
+		fatal("write %s: %s", identity_file, strerror(errno));
+	close(fd);
+	sshbuf_free(kbuf);
+	ssh_krl_free(krl);
+	sshkey_free(ca);
+}
+
+static void
+do_check_krl(struct passwd *pw, int argc, char **argv)
+{
+	int i, r, ret = 0;
+	char *comment;
+	struct ssh_krl *krl;
+	struct sshkey *k;
+
+	if (*identity_file == '\0')
+		fatal("KRL checking requires an input file");
+	load_krl(identity_file, &krl);
+	for (i = 0; i < argc; i++) {
+		if ((r = sshkey_load_public(argv[i], &k, &comment)) != 0)
+			fatal("Cannot load public key %s: %s",
+			    argv[i], ssh_err(r));
+		r = ssh_krl_check_key(krl, k);
+		printf("%s%s%s%s: %s\n", argv[i],
+		    *comment ? " (" : "", comment, *comment ? ")" : "",
+		    r == 0 ? "ok" : "REVOKED");
+		if (r != 0)
+			ret = 1;
+		sshkey_free(k);
+		free(comment);
+	}
+	ssh_krl_free(krl);
+	exit(ret);
+}
+
+static void
+usage(void)
+{
+	fprintf(stderr,
+	    "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa]\n"
+	    "                  [-N new_passphrase] [-C comment] [-f output_keyfile]\n"
+	    "       ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-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"
+	    "       ssh-keygen -c [-P passphrase] [-C comment] [-f keyfile]\n"
+	    "       ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]\n"
+	    "       ssh-keygen -B [-f input_keyfile]\n");
+#ifdef ENABLE_PKCS11
+	fprintf(stderr,
+	    "       ssh-keygen -D pkcs11\n");
+#endif
+	fprintf(stderr,
+	    "       ssh-keygen -F hostname [-f known_hosts_file] [-l]\n"
+	    "       ssh-keygen -H [-f known_hosts_file]\n"
+	    "       ssh-keygen -R hostname [-f known_hosts_file]\n"
+	    "       ssh-keygen -r hostname [-f input_keyfile] [-g]\n"
+#ifdef WITH_OPENSSL
+	    "       ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]\n"
+	    "       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] [-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"
+	    "                  file ...\n"
+	    "       ssh-keygen -Q -f krl_file file ...\n");
+	exit(1);
+}
+
+/*
+ * Main program for key management.
+ */
+int
+main(int argc, char **argv)
+{
+	char dotsshdir[PATH_MAX], comment[1024], *passphrase1, *passphrase2;
+	char *rr_hostname = NULL, *ep, *fp, *ra;
+	struct sshkey *private, *public;
+	struct passwd *pw;
+	struct stat st;
+	int r, opt, type, fd;
+	int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
+	FILE *f;
+	const char *errstr;
+#ifdef WITH_OPENSSL
+	/* Moduli generation/screening */
+	char out_file[PATH_MAX], *checkpoint = NULL;
+	u_int32_t memory = 0, generator_wanted = 0;
+	int do_gen_candidates = 0, do_screen_candidates = 0;
+	unsigned long start_lineno = 0, lines_to_process = 0;
+	BIGNUM *start = NULL;
+#endif
+
+	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();
+
+	__progname = ssh_get_progname(argv[0]);
+
+#ifdef WITH_OPENSSL
+	OpenSSL_add_all_algorithms();
+#endif
+	log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);
+
+	seed_rng();
+
+	msetlocale();
+
+	/* we need this for the home * directory.  */
+	pw = getpwuid(getuid());
+	if (!pw)
+		fatal("No user exists for uid %lu", (u_long)getuid());
+	if (gethostname(hostname, sizeof(hostname)) < 0)
+		fatal("gethostname: %s", strerror(errno));
+
+	/* 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) {
+		case 'A':
+			gen_all_hostkeys = 1;
+			break;
+		case 'b':
+			bits = (u_int32_t)strtonum(optarg, 10, 32768, &errstr);
+			if (errstr)
+				fatal("Bits has bad value %s (%s)",
+					optarg, errstr);
+			break;
+		case 'E':
+			fingerprint_hash = ssh_digest_alg_by_name(optarg);
+			if (fingerprint_hash == -1)
+				fatal("Invalid hash algorithm \"%s\"", optarg);
+			break;
+		case 'F':
+			find_host = 1;
+			rr_hostname = optarg;
+			break;
+		case 'H':
+			hash_hosts = 1;
+			break;
+		case 'I':
+			cert_key_id = optarg;
+			break;
+		case 'R':
+			delete_host = 1;
+			rr_hostname = optarg;
+			break;
+		case 'L':
+			show_cert = 1;
+			break;
+		case 'l':
+			print_fingerprint = 1;
+			break;
+		case 'B':
+			print_bubblebabble = 1;
+			break;
+		case 'm':
+			if (strcasecmp(optarg, "RFC4716") == 0 ||
+			    strcasecmp(optarg, "ssh2") == 0) {
+				convert_format = FMT_RFC4716;
+				break;
+			}
+			if (strcasecmp(optarg, "PKCS8") == 0) {
+				convert_format = FMT_PKCS8;
+				break;
+			}
+			if (strcasecmp(optarg, "PEM") == 0) {
+				convert_format = FMT_PEM;
+				use_new_format = 0;
+				break;
+			}
+			fatal("Unsupported conversion format \"%s\"", optarg);
+		case 'n':
+			cert_principals = optarg;
+			break;
+		case 'o':
+			/* no-op; new format is already the default */
+			break;
+		case 'p':
+			change_passphrase = 1;
+			break;
+		case 'c':
+			change_comment = 1;
+			break;
+		case 'f':
+			if (strlcpy(identity_file, optarg,
+			    sizeof(identity_file)) >= sizeof(identity_file))
+				fatal("Identity filename too long");
+			have_identity = 1;
+			break;
+		case 'g':
+			print_generic = 1;
+			break;
+		case 'P':
+			identity_passphrase = optarg;
+			break;
+		case 'N':
+			identity_new_passphrase = optarg;
+			break;
+		case 'Q':
+			check_krl = 1;
+			break;
+		case 'O':
+			add_cert_option(optarg);
+			break;
+		case 'Z':
+			new_format_cipher = optarg;
+			break;
+		case 'C':
+			identity_comment = optarg;
+			break;
+		case 'q':
+			quiet = 1;
+			break;
+		case 'e':
+		case 'x':
+			/* export key */
+			convert_to = 1;
+			break;
+		case 'h':
+			cert_key_type = SSH2_CERT_TYPE_HOST;
+			certflags_flags = 0;
+			break;
+		case 'k':
+			gen_krl = 1;
+			break;
+		case 'i':
+		case 'X':
+			/* import key */
+			convert_from = 1;
+			break;
+		case 'y':
+			print_public = 1;
+			break;
+		case 's':
+			ca_key_path = optarg;
+			break;
+		case 't':
+			key_type_name = optarg;
+			break;
+		case 'D':
+			pkcs11provider = optarg;
+			break;
+		case 'U':
+			prefer_agent = 1;
+			break;
+		case 'u':
+			update_krl = 1;
+			break;
+		case 'v':
+			if (log_level == SYSLOG_LEVEL_INFO)
+				log_level = SYSLOG_LEVEL_DEBUG1;
+			else {
+				if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
+				    log_level < SYSLOG_LEVEL_DEBUG3)
+					log_level++;
+			}
+			break;
+		case 'r':
+			rr_hostname = optarg;
+			break;
+		case 'a':
+			rounds = (int)strtonum(optarg, 1, INT_MAX, &errstr);
+			if (errstr)
+				fatal("Invalid number: %s (%s)",
+					optarg, errstr);
+			break;
+		case 'V':
+			parse_cert_times(optarg);
+			break;
+		case 'z':
+			errno = 0;
+			cert_serial = strtoull(optarg, &ep, 10);
+			if (*optarg < '0' || *optarg > '9' || *ep != '\0' ||
+			    (errno == ERANGE && cert_serial == ULLONG_MAX))
+				fatal("Invalid serial number \"%s\"", optarg);
+			break;
+#ifdef WITH_OPENSSL
+		/* Moduli generation/screening */
+		case 'G':
+			do_gen_candidates = 1;
+			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
+			    sizeof(out_file))
+				fatal("Output filename too long");
+			break;
+		case 'J':
+			lines_to_process = strtoul(optarg, NULL, 10);
+			break;
+		case 'j':
+			start_lineno = strtoul(optarg, NULL, 10);
+			break;
+		case 'K':
+			if (strlen(optarg) >= PATH_MAX)
+				fatal("Checkpoint filename too long");
+			checkpoint = xstrdup(optarg);
+			break;
+		case 'M':
+			memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX,
+			    &errstr);
+			if (errstr)
+				fatal("Memory limit is %s: %s", errstr, optarg);
+			break;
+		case 'S':
+			/* XXX - also compare length against bits */
+			if (BN_hex2bn(&start, optarg) == 0)
+				fatal("Invalid start point.");
+			break;
+		case 'T':
+			do_screen_candidates = 1;
+			if (strlcpy(out_file, optarg, sizeof(out_file)) >=
+			    sizeof(out_file))
+				fatal("Output filename too long");
+			break;
+		case 'W':
+			generator_wanted = (u_int32_t)strtonum(optarg, 1,
+			    UINT_MAX, &errstr);
+			if (errstr != NULL)
+				fatal("Desired generator invalid: %s (%s)",
+				    optarg, errstr);
+			break;
+#endif /* WITH_OPENSSL */
+		case '?':
+		default:
+			usage();
+		}
+	}
+
+	/* reinit */
+	log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
+
+	argv += optind;
+	argc -= optind;
+
+	if (ca_key_path != NULL) {
+		if (argc < 1 && !gen_krl) {
+			error("Too few arguments.");
+			usage();
+		}
+	} else if (argc > 0 && !gen_krl && !check_krl) {
+		error("Too many arguments.");
+		usage();
+	}
+	if (change_passphrase && change_comment) {
+		error("Can only have one of -p and -c.");
+		usage();
+	}
+	if (print_fingerprint && (delete_host || hash_hosts)) {
+		error("Cannot use -l with -H or -R.");
+		usage();
+	}
+	if (gen_krl) {
+		do_gen_krl(pw, update_krl, argc, argv);
+		return (0);
+	}
+	if (check_krl) {
+		do_check_krl(pw, argc, argv);
+		return (0);
+	}
+	if (ca_key_path != NULL) {
+		if (cert_key_id == NULL)
+			fatal("Must specify key id (-I) when certifying");
+		do_ca_sign(pw, argc, argv);
+	}
+	if (show_cert)
+		do_show_cert(pw);
+	if (delete_host || hash_hosts || find_host)
+		do_known_hosts(pw, rr_hostname);
+	if (pkcs11provider != NULL)
+		do_download(pw);
+	if (print_fingerprint || print_bubblebabble)
+		do_fingerprint(pw);
+	if (change_passphrase)
+		do_change_passphrase(pw);
+	if (change_comment)
+		do_change_comment(pw);
+#ifdef WITH_OPENSSL
+	if (convert_to)
+		do_convert_to(pw);
+	if (convert_from)
+		do_convert_from(pw);
+#endif
+	if (print_public)
+		do_print_public(pw);
+	if (rr_hostname != NULL) {
+		unsigned int n = 0;
+
+		if (have_identity) {
+			n = do_print_resource_record(pw,
+			    identity_file, rr_hostname);
+			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);
+			n += do_print_resource_record(pw,
+			    _PATH_HOST_DSA_KEY_FILE, rr_hostname);
+			n += do_print_resource_record(pw,
+			    _PATH_HOST_ECDSA_KEY_FILE, rr_hostname);
+			n += do_print_resource_record(pw,
+			    _PATH_HOST_ED25519_KEY_FILE, rr_hostname);
+			n += do_print_resource_record(pw,
+			    _PATH_HOST_XMSS_KEY_FILE, rr_hostname);
+			if (n == 0)
+				fatal("no keys found.");
+			exit(0);
+		}
+	}
+
+#ifdef WITH_OPENSSL
+	if (do_gen_candidates) {
+		FILE *out = fopen(out_file, "w");
+
+		if (out == NULL) {
+			error("Couldn't open modulus candidate file \"%s\": %s",
+			    out_file, strerror(errno));
+			return (1);
+		}
+		if (bits == 0)
+			bits = DEFAULT_BITS;
+		if (gen_candidates(out, memory, bits, start) != 0)
+			fatal("modulus candidate generation failed");
+
+		return (0);
+	}
+
+	if (do_screen_candidates) {
+		FILE *in;
+		FILE *out = fopen(out_file, "a");
+
+		if (have_identity && strcmp(identity_file, "-") != 0) {
+			if ((in = fopen(identity_file, "r")) == NULL) {
+				fatal("Couldn't open modulus candidate "
+				    "file \"%s\": %s", identity_file,
+				    strerror(errno));
+			}
+		} else
+			in = stdin;
+
+		if (out == NULL) {
+			fatal("Couldn't open moduli file \"%s\": %s",
+			    out_file, strerror(errno));
+		}
+		if (prime_test(in, out, rounds == 0 ? 100 : rounds,
+		    generator_wanted, checkpoint,
+		    start_lineno, lines_to_process) != 0)
+			fatal("modulus screening failed");
+		return (0);
+	}
+#endif
+
+	if (gen_all_hostkeys) {
+		do_gen_all_hostkeys(pw);
+		return (0);
+	}
+
+	if (key_type_name == NULL)
+		key_type_name = DEFAULT_KEY_TYPE_NAME;
+
+	type = sshkey_type_from_name(key_type_name);
+	type_bits_valid(type, key_type_name, &bits);
+
+	if (!quiet)
+		printf("Generating public/private %s key pair.\n",
+		    key_type_name);
+	if ((r = sshkey_generate(type, bits, &private)) != 0)
+		fatal("sshkey_generate failed");
+	if ((r = sshkey_from_private(private, &public)) != 0)
+		fatal("sshkey_from_private failed: %s\n", ssh_err(r));
+
+	if (!have_identity)
+		ask_filename(pw, "Enter file in which to save the key");
+
+	/* Create ~/.ssh directory if it doesn't already exist. */
+	snprintf(dotsshdir, sizeof dotsshdir, "%s/%s",
+	    pw->pw_dir, _PATH_SSH_USER_DIR);
+	if (strstr(identity_file, dotsshdir) != NULL) {
+		if (stat(dotsshdir, &st) < 0) {
+			if (errno != ENOENT) {
+				error("Could not stat %s: %s", dotsshdir,
+				    strerror(errno));
+			} else if (mkdir(dotsshdir, 0700) < 0) {
+				error("Could not create directory '%s': %s",
+				    dotsshdir, strerror(errno));
+			} else if (!quiet)
+				printf("Created directory '%s'.\n", dotsshdir);
+		}
+	}
+	/* If the file already exists, ask the user to confirm. */
+	if (stat(identity_file, &st) >= 0) {
+		char yesno[3];
+		printf("%s already exists.\n", identity_file);
+		printf("Overwrite (y/n)? ");
+		fflush(stdout);
+		if (fgets(yesno, sizeof(yesno), stdin) == NULL)
+			exit(1);
+		if (yesno[0] != 'y' && yesno[0] != 'Y')
+			exit(1);
+	}
+	/* Ask for a passphrase (twice). */
+	if (identity_passphrase)
+		passphrase1 = xstrdup(identity_passphrase);
+	else if (identity_new_passphrase)
+		passphrase1 = xstrdup(identity_new_passphrase);
+	else {
+passphrase_again:
+		passphrase1 =
+			read_passphrase("Enter passphrase (empty for no "
+			    "passphrase): ", RP_ALLOW_STDIN);
+		passphrase2 = read_passphrase("Enter same passphrase again: ",
+		    RP_ALLOW_STDIN);
+		if (strcmp(passphrase1, passphrase2) != 0) {
+			/*
+			 * The passphrases do not match.  Clear them and
+			 * retry.
+			 */
+			explicit_bzero(passphrase1, strlen(passphrase1));
+			explicit_bzero(passphrase2, strlen(passphrase2));
+			free(passphrase1);
+			free(passphrase2);
+			printf("Passphrases do not match.  Try again.\n");
+			goto passphrase_again;
+		}
+		/* Clear the other copy of the passphrase. */
+		explicit_bzero(passphrase2, strlen(passphrase2));
+		free(passphrase2);
+	}
+
+	if (identity_comment) {
+		strlcpy(comment, identity_comment, sizeof(comment));
+	} else {
+		/* Create default comment field for the passphrase. */
+		snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
+	}
+
+	/* Save the key with the given passphrase and comment. */
+	if ((r = sshkey_save_private(private, identity_file, passphrase1,
+	    comment, use_new_format, new_format_cipher, rounds)) != 0) {
+		error("Saving key \"%s\" failed: %s",
+		    identity_file, ssh_err(r));
+		explicit_bzero(passphrase1, strlen(passphrase1));
+		free(passphrase1);
+		exit(1);
+	}
+	/* Clear the passphrase. */
+	explicit_bzero(passphrase1, strlen(passphrase1));
+	free(passphrase1);
+
+	/* Clear the private key and the random number generator. */
+	sshkey_free(private);
+
+	if (!quiet)
+		printf("Your identification has been saved in %s.\n", identity_file);
+
+	strlcat(identity_file, ".pub", sizeof(identity_file));
+	if ((fd = open(identity_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
+		fatal("Unable to save public key to %s: %s",
+		    identity_file, strerror(errno));
+	if ((f = fdopen(fd, "w")) == NULL)
+		fatal("fdopen %s failed: %s", identity_file, strerror(errno));
+	if ((r = sshkey_write(public, f)) != 0)
+		error("write key failed: %s", ssh_err(r));
+	fprintf(f, " %s\n", comment);
+	if (ferror(f) || fclose(f) != 0)
+		fatal("write public failed: %s", strerror(errno));
+
+	if (!quiet) {
+		fp = sshkey_fingerprint(public, fingerprint_hash,
+		    SSH_FP_DEFAULT);
+		ra = sshkey_fingerprint(public, fingerprint_hash,
+		    SSH_FP_RANDOMART);
+		if (fp == NULL || ra == NULL)
+			fatal("sshkey_fingerprint failed");
+		printf("Your public key has been saved in %s.\n",
+		    identity_file);
+		printf("The key fingerprint is:\n");
+		printf("%s %s\n", fp, comment);
+		printf("The key's randomart image is:\n");
+		printf("%s\n", ra);
+		free(ra);
+		free(fp);
+	}
+
+	sshkey_free(public);
+	exit(0);
+}