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Revision 1.370, Mon Nov 25 00:51:37 2019 UTC (4 years, 6 months ago) by djm
Branch: MAIN
Changes since 1.369: +10 -3 lines

Add new structure for signature options

This is populated during signature verification with additional fields
that are present in and covered by the signature. At the moment, it is
only used to record security key-specific options, especially the flags
field.

with and ok markus@

/* $OpenBSD: ssh-keygen.c,v 1.370 2019/11/25 00:51:37 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 <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>

#ifdef WITH_OPENSSL
#include <openssl/evp.h>
#include <openssl/pem.h>
#endif

#include <stdint.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <limits.h>
#include <locale.h>

#include "xmalloc.h"
#include "sshkey.h"
#include "authfile.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 "atomicio.h"
#include "krl.h"
#include "digest.h"
#include "utf8.h"
#include "authfd.h"
#include "sshsig.h"
#include "ssh-sk.h"
#include "sk-api.h" /* XXX for SSH_SK_USER_PRESENCE_REQD; remove */

#ifdef ENABLE_PKCS11
#include "ssh-pkcs11.h"
#endif

#ifdef WITH_OPENSSL
# define DEFAULT_KEY_TYPE_NAME "rsa"
#else
# define DEFAULT_KEY_TYPE_NAME "ed25519"
#endif

/*
 * 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

static int quiet = 0;

/* Flag indicating that we just want to see the key fingerprint */
static int print_fingerprint = 0;
static int print_bubblebabble = 0;

/* Hash algorithm to use for fingerprints. */
static int fingerprint_hash = SSH_FP_HASH_DEFAULT;

/* The identity file name, given on the command line or entered by the user. */
static char identity_file[PATH_MAX];
static int have_identity = 0;

/* This is set to the passphrase if given on the command line. */
static char *identity_passphrase = NULL;

/* This is set to the new passphrase if given on the command line. */
static char *identity_new_passphrase = NULL;

/* Key type when certifying */
static u_int cert_key_type = SSH2_CERT_TYPE_USER;

/* "key ID" of signed key */
static char *cert_key_id = NULL;

/* Comma-separated list of principal names for certifying keys */
static char *cert_principals = NULL;

/* Validity period for certificates */
static u_int64_t cert_valid_from = 0;
static 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)
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 */
enum {
	FMT_RFC4716,
	FMT_PKCS8,
	FMT_PEM
} convert_format = FMT_RFC4716;

static char *key_type_name = NULL;

/* Load key from this PKCS#11 provider */
static char *pkcs11provider = NULL;

/* FIDO/U2F provider to use */
static char *sk_provider = NULL;

/* Format for writing private keys */
static int private_key_format = SSHKEY_PRIVATE_OPENSSH;

/* Cipher for new-format private keys */
static char *openssh_format_cipher = NULL;

/*
 * Number of KDF rounds to derive new format keys /
 * number of primality trials when screening moduli.
 */
static int rounds = 0;

/* argv0 */
extern char *__progname;

static 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)
{
	if (type == KEY_UNSPEC)
		fatal("unknown key type %s", key_type_name);
	if (*bitsp == 0) {
#ifdef WITH_OPENSSL
		u_int nid;

		switch(type) {
		case KEY_DSA:
			*bitsp = DEFAULT_BITS_DSA;
			break;
		case 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;
			break;
		case KEY_RSA:
			*bitsp = DEFAULT_BITS;
			break;
		}
#endif
	}
#ifdef WITH_OPENSSL
	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);
		else if (*bitsp > OPENSSL_RSA_MAX_MODULUS_BITS)
			fatal("Invalid RSA key length: maximum is %d bits",
			    OPENSSL_RSA_MAX_MODULUS_BITS);
		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
}

/*
 * Checks whether a file exists and, if so, asks the user whether they wish
 * to overwrite it.
 * Returns nonzero if the file does not already exist or if the user agrees to
 * overwrite, or zero otherwise.
 */
static int
confirm_overwrite(const char *filename)
{
	char yesno[3];
	struct stat st;

	if (stat(filename, &st) != 0)
		return 1;
	printf("%s already exists.\n", filename);
	printf("Overwrite (y/n)? ");
	fflush(stdout);
	if (fgets(yesno, sizeof(yesno), stdin) == NULL)
		return 0;
	if (yesno[0] != 'y' && yesno[0] != 'Y')
		return 0;
	return 1;
}

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;
		case KEY_ECDSA_CERT:
		case KEY_ECDSA:
			name = _PATH_SSH_CLIENT_ID_ECDSA;
			break;
		case KEY_ECDSA_SK_CERT:
		case KEY_ECDSA_SK:
			name = _PATH_SSH_CLIENT_ID_ECDSA_SK;
			break;
		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_ED25519_SK:
		case KEY_ED25519_SK_CERT:
			name = _PATH_SSH_CLIENT_ID_ED25519_SK;
			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(const char *filename, char **commentp)
{
	char *pass;
	struct sshkey *prv;
	int r;

	if (commentp != NULL)
		*commentp = NULL;
	if ((r = sshkey_load_private(filename, "", &prv, commentp)) == 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, commentp);
	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)
{
	struct sshbuf *b;
	char comment[61], *b64;
	int r;

	if ((b = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new failed", __func__);
	if ((r = sshkey_putb(k, b)) != 0)
		fatal("key_to_blob failed: %s", ssh_err(r));
	if ((b64 = sshbuf_dtob64_string(b, 1)) == NULL)
		fatal("%s: sshbuf_dtob64_string failed", __func__);

	/* 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);

	sshkey_free(k);
	sshbuf_free(b);

	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
	fprintf(stdout, "Comment: \"%s\"\n%s", comment, b64);
	fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
	free(b64);
	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;
	case KEY_ECDSA:
		if (!PEM_write_EC_PUBKEY(stdout, k->ecdsa))
			fatal("PEM_write_EC_PUBKEY failed");
		break;
	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) == -1)
		fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
	if ((r = sshkey_load_public(identity_file, &k, NULL)) != 0)
		k = load_identity(identity_file, NULL);
	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(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 ((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);
		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);
		free(type);
		return NULL;
	}
	free(cipher);

	if (strstr(type, "dsa")) {
		ktype = KEY_DSA;
	} else if (strstr(type, "rsa")) {
		ktype = KEY_RSA;
	} else {
		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);
			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("%s: remaining bytes in key blob %d", __func__, rlen);

	/* try the key */
	if (sshkey_sign(key, &sig, &slen, data, sizeof(data),
	    NULL, NULL, 0) != 0 ||
	    sshkey_verify(key, sig, slen, data, sizeof(data),
	    NULL, 0, NULL) != 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];
	struct sshbuf *buf;
	char encoded[8096];
	FILE *fp;

	if ((buf = sshbuf_new()) == NULL)
		fatal("sshbuf_new failed");
	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';
	if ((r = sshbuf_b64tod(buf, encoded)) != 0)
		fatal("%s: base64 decoding failed: %s", __func__, ssh_err(r));
	if (*private)
		*k = do_convert_private_ssh2(buf);
	else if ((r = sshkey_fromb(buf, k)) != 0)
		fatal("decode blob failed: %s", ssh_err(r));
	sshbuf_free(buf);
	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;
	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;
	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) == -1)
		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;
		case KEY_ECDSA:
			ok = PEM_write_ECPrivateKey(stdout, k->ecdsa, NULL,
			    NULL, 0, NULL, NULL);
			break;
		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;
	char *comment = NULL;

	if (!have_identity)
		ask_filename(pw, "Enter file in which the key is");
	if (stat(identity_file, &st) == -1)
		fatal("%s: %s", identity_file, strerror(errno));
	prv = load_identity(identity_file, &comment);
	if ((r = sshkey_write(prv, stdout)) != 0)
		error("sshkey_write failed: %s", ssh_err(r));
	sshkey_free(prv);
	if (comment != NULL && *comment != '\0')
		fprintf(stdout, " %s", comment);
	fprintf(stdout, "\n");
	free(comment);
	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(1);
	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_get() >= 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_get() >= 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) == -1)
		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 },
		{ "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_int32_t bits = 0;
	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, private_key_format, openssh_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 */
	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
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 && !ctx->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 = NULL, *ra = NULL;

	fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
	rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;

	if (l->status == HKF_STATUS_MATCHED) {
		if (ctx->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 (ctx->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 (ctx->hash_hosts)
				known_hosts_hash(l, ctx);
			else if (print_fingerprint) {
				fp = sshkey_fingerprint(l->key, fptype, rep);
				ra = sshkey_fingerprint(l->key,
				    fingerprint_hash, SSH_FP_RANDOMART);
				if (fp == NULL || ra == NULL)
					fatal("%s: sshkey_fingerprint failed",
					    __func__);
				mprintf("%s %s %s %s\n", ctx->host,
				    sshkey_type(l->key), fp, l->comment);
				if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
					printf("%s\n", ra);
				free(ra);
				free(fp);
			} else
				fprintf(ctx->out, "%s\n", l->line);
			return 0;
		}
	} else if (ctx->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, int find_host,
    int delete_host, int hash_hosts)
{
	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;
	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
	 * 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) == -1)
		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, private_key_format, openssh_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,
    int print_generic)
{
	struct sshkey *public;
	char *comment = NULL;
	struct stat st;
	int r;

	if (fname == NULL)
		fatal("%s: no filename", __func__);
	if (stat(fname, &st) == -1) {
		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, const char *identity_comment)
{
	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) == -1)
		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 &&
	    private_key_format != SSHKEY_PRIVATE_OPENSSH) {
		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("Old comment: %s\n", comment);
	else
		printf("No existing comment\n");

	if (identity_comment) {
		strlcpy(new_comment, identity_comment, sizeof(new_comment));
	} else {
		printf("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';
	}
	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,
	    new_comment, private_key_format, openssh_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);

	if (strlen(new_comment) > 0)
		printf("Comment '%s' applied\n", new_comment);
	else
		printf("Comment removed\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(struct sshkey *key, u_char **sigp, size_t *lenp,
    const u_char *data, size_t datalen,
    const char *alg, const char *provider, 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, 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, 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, NULL);
	}
	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 (sshkey_is_cert(public))
			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, sk_provider, agent_signer,
			    &agent_fd)) != 0)
				fatal("Couldn't certify key %s via agent: %s",
				    tmp, ssh_err(r));
		} else {
			if ((r = sshkey_certify(public, ca, key_type_name,
			    sk_provider)) != 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);
		if (cert_serial_autoinc)
			cert_serial++;
	}
#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 (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);
	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) == -1)
		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);
}

#ifdef WITH_OPENSSL
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, 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;
	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 (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);

	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);
}
#endif

static struct sshkey *
load_sign_key(const char *keypath, const struct sshkey *pubkey)
{
	size_t i, slen, plen = strlen(keypath);
	char *privpath = xstrdup(keypath);
	const char *suffixes[] = { "-cert.pub", ".pub", NULL };
	struct sshkey *ret = NULL, *privkey = NULL;
	int r;

	/*
	 * If passed a public key filename, then try to locate the correponding
	 * private key. This lets us specify certificates on the command-line
	 * and have ssh-keygen find the appropriate private key.
	 */
	for (i = 0; suffixes[i]; i++) {
		slen = strlen(suffixes[i]);
		if (plen <= slen ||
		    strcmp(privpath + plen - slen, suffixes[i]) != 0)
			continue;
		privpath[plen - slen] = '\0';
		debug("%s: %s looks like a public key, using private key "
		    "path %s instead", __func__, keypath, privpath);
	}
	if ((privkey = load_identity(privpath, NULL)) == NULL) {
		error("Couldn't load identity %s", keypath);
		goto done;
	}
	if (!sshkey_equal_public(pubkey, privkey)) {
		error("Public key %s doesn't match private %s",
		    keypath, privpath);
		goto done;
	}
	if (sshkey_is_cert(pubkey) && !sshkey_is_cert(privkey)) {
		/*
		 * Graft the certificate onto the private key to make
		 * it capable of signing.
		 */
		if ((r = sshkey_to_certified(privkey)) != 0) {
			error("%s: sshkey_to_certified: %s", __func__,
			    ssh_err(r));
			goto done;
		}
		if ((r = sshkey_cert_copy(pubkey, privkey)) != 0) {
			error("%s: sshkey_cert_copy: %s", __func__, ssh_err(r));
			goto done;
		}
	}
	/* success */
	ret = privkey;
	privkey = NULL;
 done:
	sshkey_free(privkey);
	free(privpath);
	return ret;
}

static int
sign_one(struct sshkey *signkey, const char *filename, int fd,
    const char *sig_namespace, sshsig_signer *signer, void *signer_ctx)
{
	struct sshbuf *sigbuf = NULL, *abuf = NULL;
	int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno;
	char *wfile = NULL, *asig = NULL, *fp = NULL;

	if (!quiet) {
		if (fd == STDIN_FILENO)
			fprintf(stderr, "Signing data on standard input\n");
		else
			fprintf(stderr, "Signing file %s\n", filename);
	}
	if (signer == NULL && sshkey_is_sk(signkey) &&
	    (signkey->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
		if ((fp = sshkey_fingerprint(signkey, fingerprint_hash,
		    SSH_FP_DEFAULT)) == NULL)
			fatal("%s: sshkey_fingerprint failed", __func__);
		fprintf(stderr, "Confirm user presence for key %s %s\n",
		    sshkey_type(signkey), fp);
		free(fp);
	}
	if ((r = sshsig_sign_fd(signkey, NULL, sk_provider, fd, sig_namespace,
	    &sigbuf, signer, signer_ctx)) != 0) {
		error("Signing %s failed: %s", filename, ssh_err(r));
		goto out;
	}
	if ((r = sshsig_armor(sigbuf, &abuf)) != 0) {
		error("%s: sshsig_armor: %s", __func__, ssh_err(r));
		goto out;
	}
	if ((asig = sshbuf_dup_string(abuf)) == NULL) {
		error("%s: buffer error", __func__);
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}

	if (fd == STDIN_FILENO) {
		fputs(asig, stdout);
		fflush(stdout);
	} else {
		xasprintf(&wfile, "%s.sig", filename);
		if (confirm_overwrite(wfile)) {
			if ((wfd = open(wfile, O_WRONLY|O_CREAT|O_TRUNC,
			    0666)) == -1) {
				oerrno = errno;
				error("Cannot open %s: %s",
				    wfile, strerror(errno));
				errno = oerrno;
				r = SSH_ERR_SYSTEM_ERROR;
				goto out;
			}
			if (atomicio(vwrite, wfd, asig,
			    strlen(asig)) != strlen(asig)) {
				oerrno = errno;
				error("Cannot write to %s: %s",
				    wfile, strerror(errno));
				errno = oerrno;
				r = SSH_ERR_SYSTEM_ERROR;
				goto out;
			}
			if (!quiet) {
				fprintf(stderr, "Write signature to %s\n",
				    wfile);
			}
		}
	}
	/* success */
	r = 0;
 out:
	free(wfile);
	free(asig);
	sshbuf_free(abuf);
	sshbuf_free(sigbuf);
	if (wfd != -1)
		close(wfd);
	return r;
}

static int
sign(const char *keypath, const char *sig_namespace, int argc, char **argv)
{
	int i, fd = -1, r, ret = -1;
	int agent_fd = -1;
	struct sshkey *pubkey = NULL, *privkey = NULL, *signkey = NULL;
	sshsig_signer *signer = NULL;

	/* Check file arguments. */
	for (i = 0; i < argc; i++) {
		if (strcmp(argv[i], "-") != 0)
			continue;
		if (i > 0 || argc > 1)
			fatal("Cannot sign mix of paths and standard input");
	}

	if ((r = sshkey_load_public(keypath, &pubkey, NULL)) != 0) {
		error("Couldn't load public key %s: %s", keypath, ssh_err(r));
		goto done;
	}

	if ((r = ssh_get_authentication_socket(&agent_fd)) != 0)
		debug("Couldn't get agent socket: %s", ssh_err(r));
	else {
		if ((r = ssh_agent_has_key(agent_fd, pubkey)) == 0)
			signer = agent_signer;
		else
			debug("Couldn't find key in agent: %s", ssh_err(r));
	}

	if (signer == NULL) {
		/* Not using agent - try to load private key */
		if ((privkey = load_sign_key(keypath, pubkey)) == NULL)
			goto done;
		signkey = privkey;
	} else {
		/* Will use key in agent */
		signkey = pubkey;
	}

	if (argc == 0) {
		if ((r = sign_one(signkey, "(stdin)", STDIN_FILENO,
		    sig_namespace, signer, &agent_fd)) != 0)
			goto done;
	} else {
		for (i = 0; i < argc; i++) {
			if (strcmp(argv[i], "-") == 0)
				fd = STDIN_FILENO;
			else if ((fd = open(argv[i], O_RDONLY)) == -1) {
				error("Cannot open %s for signing: %s",
				    argv[i], strerror(errno));
				goto done;
			}
			if ((r = sign_one(signkey, argv[i], fd, sig_namespace,
			    signer, &agent_fd)) != 0)
				goto done;
			if (fd != STDIN_FILENO)
				close(fd);
			fd = -1;
		}
	}

	ret = 0;
done:
	if (fd != -1 && fd != STDIN_FILENO)
		close(fd);
	sshkey_free(pubkey);
	sshkey_free(privkey);
	return ret;
}

static int
verify(const char *signature, const char *sig_namespace, const char *principal,
    const char *allowed_keys, const char *revoked_keys)
{
	int r, ret = -1, sigfd = -1;
	struct sshbuf *sigbuf = NULL, *abuf = NULL;
	struct sshkey *sign_key = NULL;
	char *fp = NULL;
	struct sshkey_sig_details *sig_details = NULL;

	memset(&sig_details, 0, sizeof(sig_details));
	if ((abuf = sshbuf_new()) == NULL)
		fatal("%s: sshbuf_new() failed", __func__);

	if ((sigfd = open(signature, O_RDONLY)) < 0) {
		error("Couldn't open signature file %s", signature);
		goto done;
	}

	if ((r = sshkey_load_file(sigfd, abuf)) != 0) {
		error("Couldn't read signature file: %s", ssh_err(r));
		goto done;
	}
	if ((r = sshsig_dearmor(abuf, &sigbuf)) != 0) {
		error("%s: sshsig_armor: %s", __func__, ssh_err(r));
		return r;
	}
	if ((r = sshsig_verify_fd(sigbuf, STDIN_FILENO, sig_namespace,
	    &sign_key, &sig_details)) != 0)
		goto done; /* sshsig_verify() prints error */

	if ((fp = sshkey_fingerprint(sign_key, fingerprint_hash,
	    SSH_FP_DEFAULT)) == NULL)
		fatal("%s: sshkey_fingerprint failed", __func__);
	debug("Valid (unverified) signature from key %s", fp);
	if (sig_details != NULL) {
		debug2("%s: signature details: counter = %u, flags = 0x%02x",
		    __func__, sig_details->sk_counter, sig_details->sk_flags);
	}
	free(fp);
	fp = NULL;

	if (revoked_keys != NULL) {
		if ((r = sshkey_check_revoked(sign_key, revoked_keys)) != 0) {
			debug3("sshkey_check_revoked failed: %s", ssh_err(r));
			goto done;
		}
	}

	if (allowed_keys != NULL &&
	    (r = sshsig_check_allowed_keys(allowed_keys, sign_key,
					   principal, sig_namespace)) != 0) {
		debug3("sshsig_check_allowed_keys failed: %s", ssh_err(r));
		goto done;
	}
	/* success */
	ret = 0;
done:
	if (!quiet) {
		if (ret == 0) {
			if ((fp = sshkey_fingerprint(sign_key, fingerprint_hash,
			    SSH_FP_DEFAULT)) == NULL) {
				fatal("%s: sshkey_fingerprint failed",
				    __func__);
			}
			if (principal == NULL) {
				printf("Good \"%s\" signature with %s key %s\n",
				       sig_namespace, sshkey_type(sign_key), fp);

			} else {
				printf("Good \"%s\" signature for %s with %s key %s\n",
				       sig_namespace, principal,
				       sshkey_type(sign_key), fp);
			}
		} else {
			printf("Could not verify signature.\n");
		}
	}
	if (sigfd != -1)
		close(sigfd);
	sshbuf_free(sigbuf);
	sshbuf_free(abuf);
	sshkey_free(sign_key);
	sshkey_sig_details_free(sig_details);
	free(fp);
	return ret;
}

static void
usage(void)
{
	fprintf(stderr,
	    "usage: ssh-keygen [-q] [-b bits] [-C comment] [-f output_keyfile] [-m format]\n"
	    "                  [-t dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa]\n"
	    "                  [-N new_passphrase] [-w provider] [-x flags]\n"
	    "       ssh-keygen -p [-f keyfile] [-m format] [-N new_passphrase]\n"
	    "                   [-P old_passphrase]\n"
	    "       ssh-keygen -i [-f input_keyfile] [-m key_format]\n"
	    "       ssh-keygen -e [-f input_keyfile] [-m key_format]\n"
	    "       ssh-keygen -y [-f input_keyfile]\n"
	    "       ssh-keygen -c [-C comment] [-f keyfile] [-P passphrase]\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 [-lv] [-f known_hosts_file]\n"
	    "       ssh-keygen -H [-f known_hosts_file]\n"
	    "       ssh-keygen -R hostname [-f known_hosts_file]\n"
	    "       ssh-keygen -r hostname [-g] [-f input_keyfile]\n"
#ifdef WITH_OPENSSL
	    "       ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]\n"
	    "       ssh-keygen -f input_file -T output_file [-v] [-a rounds] [-J num_lines]\n"
	    "                  [-j start_line] [-K checkpt] [-W generator]\n"
#endif
	    "       ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]\n"
	    "                  [-n principals] [-O option] [-V validity_interval]\n"
	    "                  [-z serial_number] file ...\n"
	    "       ssh-keygen -L [-f input_keyfile]\n"
	    "       ssh-keygen -A [-f prefix_path]\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"
	    "       ssh-keygen -Y check-novalidate -n namespace -s signature_file\n"
	    "       ssh-keygen -Y sign -f key_file -n namespace file ...\n"
	    "       ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n"
	    "       		-n namespace -s signature_file [-r revocation_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 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 ull, cert_serial = 0;
	char *identity_comment = NULL, *ca_key_path = NULL;
	u_int32_t bits = 0;
	uint8_t sk_flags = SSH_SK_USER_PRESENCE_REQD;
	FILE *f;
	const char *errstr;
	int log_level = SYSLOG_LEVEL_INFO;
	char *sign_op = NULL;
#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;

	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
	sanitise_stdfd();

#ifdef WITH_OPENSSL
	OpenSSL_add_all_algorithms();
#endif
	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)
		fatal("No user exists for uid %lu", (u_long)getuid());
	if (gethostname(hostname, sizeof(hostname)) == -1)
		fatal("gethostname: %s", strerror(errno));

	sk_provider = getenv("SSH_SK_PROVIDER");

	/* Remaining character: d */
	while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvy"
	    "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Y:Z:"
	    "a:b:f:g:j:m:n:r:s:t:w:x:z:")) != -1) {
		switch (opt) {
		case 'A':
			gen_all_hostkeys = 1;
			break;
		case 'b':
			bits = (u_int32_t)strtonum(optarg, 1, UINT32_MAX,
			    &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;
				private_key_format = SSHKEY_PRIVATE_PKCS8;
				break;
			}
			if (strcasecmp(optarg, "PEM") == 0) {
				convert_format = FMT_PEM;
				private_key_format = SSHKEY_PRIVATE_PEM;
				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':
			openssh_format_cipher = optarg;
			break;
		case 'C':
			identity_comment = optarg;
			break;
		case 'q':
			quiet = 1;
			break;
		case 'e':
			/* 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 'Y':
			sign_op = optarg;
			break;
		case 'w':
			sk_provider = optarg;
			break;
		case 'x':
			if (*optarg == '\0')
				fatal("Missing security key flags");
			ull = strtoull(optarg, &ep, 0);
			if (*ep != '\0')
				fatal("Security key flags \"%s\" is not a "
				    "number", optarg);
			if (ull > 0xff)
				fatal("Invalid security key flags 0x%llx", ull);
			sk_flags = (uint8_t)ull;
			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))
				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();
		}
	}

	if (sk_provider == NULL)
		sk_provider = "internal";

	/* reinit */
	log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);

	argv += optind;
	argc -= optind;

	if (sign_op != NULL) {
		if (cert_principals == NULL || *cert_principals == '\0') {
			error("Too few arguments for sign/verify: "
			    "missing namespace");
			exit(1);
		}
		if (strncmp(sign_op, "sign", 4) == 0) {
			if (!have_identity) {
				error("Too few arguments for sign: "
				    "missing key");
				exit(1);
			}
			return sign(identity_file, cert_principals, argc, argv);
		} else if (strncmp(sign_op, "check-novalidate", 16) == 0) {
			if (ca_key_path == NULL) {
				error("Too few arguments for check-novalidate: "
				      "missing signature file");
				exit(1);
			}
			return verify(ca_key_path, cert_principals,
				      NULL, NULL, NULL);
		} else if (strncmp(sign_op, "verify", 6) == 0) {
			if (ca_key_path == NULL) {
				error("Too few arguments for verify: "
				    "missing signature file");
				exit(1);
			}
			if (!have_identity) {
				error("Too few arguments for sign: "
				    "missing allowed keys file");
				exit(1);
			}
			if (cert_key_id == NULL) {
				error("Too few arguments for verify: "
				    "missing principal ID");
				exit(1);
			}
			return verify(ca_key_path, cert_principals,
			    cert_key_id, identity_file, rr_hostname);
		}
		usage();
		/* NOTREACHED */
	}

	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();
	}
#ifdef WITH_OPENSSL
	if (gen_krl) {
		do_gen_krl(pw, update_krl, ca_key_path,
		    cert_serial, identity_comment, argc, argv);
		return (0);
	}
	if (check_krl) {
		do_check_krl(pw, argc, argv);
		return (0);
	}
#endif
	if (ca_key_path != NULL) {
		if (cert_key_id == NULL)
			fatal("Must specify key id (-I) when certifying");
		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, find_host,
		    delete_host, hash_hosts);
	}
	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, identity_comment);
#ifdef WITH_OPENSSL
	if (convert_to)
		do_convert_to(pw);
	if (convert_from)
		do_convert_from(pw);
#else /* WITH_OPENSSL */
	if (convert_to || convert_from)
		fatal("key conversion disabled at compile time");
#endif /* WITH_OPENSSL */
	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, 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,
			    print_generic);
			n += do_print_resource_record(pw,
			    _PATH_HOST_DSA_KEY_FILE, rr_hostname,
			    print_generic);
			n += do_print_resource_record(pw,
			    _PATH_HOST_ECDSA_KEY_FILE, rr_hostname,
			    print_generic);
			n += do_print_resource_record(pw,
			    _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);
		}
	}

#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);
	switch (type) {
	case KEY_ECDSA_SK:
	case KEY_ED25519_SK:
		if (sshsk_enroll(type, sk_provider,
		    cert_key_id == NULL ? "ssh:" : cert_key_id,
		    sk_flags, NULL, &private, NULL) != 0)
			exit(1); /* error message already printed */
		break;
	default:
		if ((r = sshkey_generate(type, bits, &private)) != 0)
			fatal("sshkey_generate failed");
		break;
	}
	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) == -1) {
			if (errno != ENOENT) {
				error("Could not stat %s: %s", dotsshdir,
				    strerror(errno));
			} else if (mkdir(dotsshdir, 0700) == -1) {
				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 (!confirm_overwrite(identity_file))
		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, private_key_format, openssh_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);
}