vkernel - Fixup previous commit, where some bits got lost during rebaseing.

[dragonfly.git] / crypto / openssh / ssh-keygen.c

/* $OpenBSD: ssh-keygen.c,v 1.290 2016/05/02 09:36:42 djm Exp $ */
/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Identity and host key generation and maintenance.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>

#ifdef WITH_OPENSSL
#include <openssl/evp.h>
#include <openssl/pem.h>
#include "openbsd-compat/openssl-compat.h"
#endif

#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <limits.h>

#include "xmalloc.h"
#include "sshkey.h"
#include "rsa.h"
#include "authfile.h"
#include "uuencode.h"
#include "sshbuf.h"
#include "pathnames.h"
#include "log.h"
#include "misc.h"
#include "match.h"
#include "hostfile.h"
#include "dns.h"
#include "ssh.h"
#include "ssh2.h"
#include "ssherr.h"
#include "ssh-pkcs11.h"
#include "atomicio.h"
#include "krl.h"
#include "digest.h"

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

/* Number of bits in the RSA/DSA key.  This value can be set on the command line. */
#define DEFAULT_BITS            2048
#define DEFAULT_BITS_DSA        1024
#define DEFAULT_BITS_ECDSA      256
u_int32_t bits = 0;

/*
 * Flag indicating that we just want to change the passphrase.  This can be
 * set on the command line.
 */
int change_passphrase = 0;

/*
 * Flag indicating that we just want to change the comment.  This can be set
 * on the command line.
 */
int change_comment = 0;

int quiet = 0;

int log_level = SYSLOG_LEVEL_INFO;

/* Flag indicating that we want to hash a known_hosts file */
int hash_hosts = 0;
/* Flag indicating that we want lookup a host in known_hosts file */
int find_host = 0;
/* Flag indicating that we want to delete a host from a known_hosts file */
int delete_host = 0;

/* Flag indicating that we want to show the contents of a certificate */
int show_cert = 0;

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

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

/* The identity file name, given on the command line or entered by the user. */
char identity_file[1024];
int have_identity = 0;

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

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

/* This is set to the new comment if given on the command line. */
char *identity_comment = NULL;

/* Path to CA key when certifying keys. */
char *ca_key_path = NULL;

/* Certificate serial number */
unsigned long long cert_serial = 0;

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

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

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

/* Validity period for certificates */
u_int64_t cert_valid_from = 0;
u_int64_t cert_valid_to = ~0ULL;

/* Certificate options */
#define CERTOPT_X_FWD   (1)
#define CERTOPT_AGENT_FWD       (1<<1)
#define CERTOPT_PORT_FWD        (1<<2)
#define CERTOPT_PTY             (1<<3)
#define CERTOPT_USER_RC (1<<4)
#define CERTOPT_DEFAULT (CERTOPT_X_FWD|CERTOPT_AGENT_FWD| \
                         CERTOPT_PORT_FWD|CERTOPT_PTY|CERTOPT_USER_RC)
u_int32_t certflags_flags = CERTOPT_DEFAULT;
char *certflags_command = NULL;
char *certflags_src_addr = NULL;

/* Conversion to/from various formats */
int convert_to = 0;
int convert_from = 0;
enum {
        FMT_RFC4716,
        FMT_PKCS8,
        FMT_PEM
} convert_format = FMT_RFC4716;
int print_public = 0;
int print_generic = 0;

char *key_type_name = NULL;

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

/* Use new OpenSSH private key format when writing SSH2 keys instead of PEM */
int use_new_format = 0;

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

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

/* argv0 */
extern char *__progname;

char hostname[NI_MAXHOST];

#ifdef WITH_OPENSSL
/* moduli.c */
int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
int prime_test(FILE *, FILE *, u_int32_t, u_int32_t, char *, unsigned long,
    unsigned long);
#endif

static void
type_bits_valid(int type, const char *name, u_int32_t *bitsp)
{
#ifdef WITH_OPENSSL
        u_int maxbits, nid;
#endif

        if (type == KEY_UNSPEC)
                fatal("unknown key type %s", key_type_name);
        if (*bitsp == 0) {
#ifdef WITH_OPENSSL
                if (type == KEY_DSA)
                        *bitsp = DEFAULT_BITS_DSA;
                else if (type == KEY_ECDSA) {
                        if (name != NULL &&
                            (nid = sshkey_ecdsa_nid_from_name(name)) > 0)
                                *bitsp = sshkey_curve_nid_to_bits(nid);
                        if (*bitsp == 0)
                                *bitsp = DEFAULT_BITS_ECDSA;
                } else
#endif
                        *bitsp = DEFAULT_BITS;
        }
#ifdef WITH_OPENSSL
        maxbits = (type == KEY_DSA) ?
            OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
        if (*bitsp > maxbits)
                fatal("key bits exceeds maximum %d", maxbits);
        if (type == KEY_DSA && *bitsp != 1024)
                fatal("DSA keys must be 1024 bits");
        else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 1024)
                fatal("Key must at least be 1024 bits");
        else if (type == KEY_ECDSA && sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
                fatal("Invalid ECDSA key length - valid lengths are "
                    "256, 384 or 521 bits");
#endif
}

static void
ask_filename(struct passwd *pw, const char *prompt)
{
        char buf[1024];
        char *name = NULL;

        if (key_type_name == NULL)
                name = _PATH_SSH_CLIENT_ID_RSA;
        else {
                switch (sshkey_type_from_name(key_type_name)) {
                case KEY_RSA1:
                        name = _PATH_SSH_CLIENT_IDENTITY;
                        break;
                case KEY_DSA_CERT:
                case KEY_DSA:
                        name = _PATH_SSH_CLIENT_ID_DSA;
                        break;
#ifdef OPENSSL_HAS_ECC
                case KEY_ECDSA_CERT:
                case KEY_ECDSA:
                        name = _PATH_SSH_CLIENT_ID_ECDSA;
                        break;
#endif
                case KEY_RSA_CERT:
                case KEY_RSA:
                        name = _PATH_SSH_CLIENT_ID_RSA;
                        break;
                case KEY_ED25519:
                case KEY_ED25519_CERT:
                        name = _PATH_SSH_CLIENT_ID_ED25519;
                        break;
                default:
                        fatal("bad key type");
                }
        }
        snprintf(identity_file, sizeof(identity_file),
            "%s/%s", pw->pw_dir, name);
        printf("%s (%s): ", prompt, identity_file);
        fflush(stdout);
        if (fgets(buf, sizeof(buf), stdin) == NULL)
                exit(1);
        buf[strcspn(buf, "\n")] = '\0';
        if (strcmp(buf, "") != 0)
                strlcpy(identity_file, buf, sizeof(identity_file));
        have_identity = 1;
}

static struct sshkey *
load_identity(char *filename)
{
        char *pass;
        struct sshkey *prv;
        int r;

        if ((r = sshkey_load_private(filename, "", &prv, NULL)) == 0)
                return prv;
        if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
                fatal("Load key \"%s\": %s", filename, ssh_err(r));
        if (identity_passphrase)
                pass = xstrdup(identity_passphrase);
        else
                pass = read_passphrase("Enter passphrase: ", RP_ALLOW_STDIN);
        r = sshkey_load_private(filename, pass, &prv, NULL);
        explicit_bzero(pass, strlen(pass));
        free(pass);
        if (r != 0)
                fatal("Load key \"%s\": %s", filename, ssh_err(r));
        return prv;
}

#define SSH_COM_PUBLIC_BEGIN            "---- BEGIN SSH2 PUBLIC KEY ----"
#define SSH_COM_PUBLIC_END              "---- END SSH2 PUBLIC KEY ----"
#define SSH_COM_PRIVATE_BEGIN           "---- BEGIN SSH2 ENCRYPTED PRIVATE KEY ----"
#define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb

#ifdef WITH_OPENSSL
static void
do_convert_to_ssh2(struct passwd *pw, struct sshkey *k)
{
        size_t len;
        u_char *blob;
        char comment[61];
        int r;

        if (k->type == KEY_RSA1)
                fatal("version 1 keys are not supported");
        if ((r = sshkey_to_blob(k, &blob, &len)) != 0)
                fatal("key_to_blob failed: %s", ssh_err(r));
        /* Comment + surrounds must fit into 72 chars (RFC 4716 sec 3.3) */
        snprintf(comment, sizeof(comment),
            "%u-bit %s, converted by %s@%s from OpenSSH",
            sshkey_size(k), sshkey_type(k),
            pw->pw_name, hostname);

        fprintf(stdout, "%s\n", SSH_COM_PUBLIC_BEGIN);
        fprintf(stdout, "Comment: \"%s\"\n", comment);
        dump_base64(stdout, blob, len);
        fprintf(stdout, "%s\n", SSH_COM_PUBLIC_END);
        sshkey_free(k);
        free(blob);
        exit(0);
}

static void
do_convert_to_pkcs8(struct sshkey *k)
{
        switch (sshkey_type_plain(k->type)) {
        case KEY_RSA1:
        case KEY_RSA:
                if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
                        fatal("PEM_write_RSA_PUBKEY failed");
                break;
        case KEY_DSA:
                if (!PEM_write_DSA_PUBKEY(stdout, k->dsa))
                        fatal("PEM_write_DSA_PUBKEY failed");
                break;
#ifdef OPENSSL_HAS_ECC
        case KEY_ECDSA:
                if (!PEM_write_EC_PUBKEY(stdout, k->ecdsa))
                        fatal("PEM_write_EC_PUBKEY failed");
                break;
#endif
        default:
                fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
        }
        exit(0);
}

static void
do_convert_to_pem(struct sshkey *k)
{
        switch (sshkey_type_plain(k->type)) {
        case KEY_RSA1:
        case KEY_RSA:
                if (!PEM_write_RSAPublicKey(stdout, k->rsa))
                        fatal("PEM_write_RSAPublicKey failed");
                break;
#if notyet /* OpenSSH 0.9.8 lacks this function */
        case KEY_DSA:
                if (!PEM_write_DSAPublicKey(stdout, k->dsa))
                        fatal("PEM_write_DSAPublicKey failed");
                break;
#endif
        /* XXX ECDSA? */
        default:
                fatal("%s: unsupported key type %s", __func__, sshkey_type(k));
        }
        exit(0);
}

static void
do_convert_to(struct passwd *pw)
{
        struct sshkey *k;
        struct stat st;
        int r;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (stat(identity_file, &st) < 0)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
        if ((r = sshkey_load_public(identity_file, &k, NULL)) != 0)
                k = load_identity(identity_file);
        switch (convert_format) {
        case FMT_RFC4716:
                do_convert_to_ssh2(pw, k);
                break;
        case FMT_PKCS8:
                do_convert_to_pkcs8(k);
                break;
        case FMT_PEM:
                do_convert_to_pem(k);
                break;
        default:
                fatal("%s: unknown key format %d", __func__, convert_format);
        }
        exit(0);
}

/*
 * This is almost exactly the bignum1 encoding, but with 32 bit for length
 * instead of 16.
 */
static void
buffer_get_bignum_bits(struct sshbuf *b, BIGNUM *value)
{
        u_int bytes, bignum_bits;
        int r;

        if ((r = sshbuf_get_u32(b, &bignum_bits)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));
        bytes = (bignum_bits + 7) / 8;
        if (sshbuf_len(b) < bytes)
                fatal("%s: input buffer too small: need %d have %zu",
                    __func__, bytes, sshbuf_len(b));
        if (BN_bin2bn(sshbuf_ptr(b), bytes, value) == NULL)
                fatal("%s: BN_bin2bn failed", __func__);
        if ((r = sshbuf_consume(b, bytes)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));
}

static struct sshkey *
do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
{
        struct sshbuf *b;
        struct sshkey *key = NULL;
        char *type, *cipher;
        u_char e1, e2, e3, *sig = NULL, data[] = "abcde12345";
        int r, rlen, ktype;
        u_int magic, i1, i2, i3, i4;
        size_t slen;
        u_long e;

        if ((b = sshbuf_from(blob, blen)) == NULL)
                fatal("%s: sshbuf_from failed", __func__);
        if ((r = sshbuf_get_u32(b, &magic)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));

        if (magic != SSH_COM_PRIVATE_KEY_MAGIC) {
                error("bad magic 0x%x != 0x%x", magic,
                    SSH_COM_PRIVATE_KEY_MAGIC);
                sshbuf_free(b);
                return NULL;
        }
        if ((r = sshbuf_get_u32(b, &i1)) != 0 ||
            (r = sshbuf_get_cstring(b, &type, NULL)) != 0 ||
            (r = sshbuf_get_cstring(b, &cipher, NULL)) != 0 ||
            (r = sshbuf_get_u32(b, &i2)) != 0 ||
            (r = sshbuf_get_u32(b, &i3)) != 0 ||
            (r = sshbuf_get_u32(b, &i4)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));
        debug("ignore (%d %d %d %d)", i1, i2, i3, i4);
        if (strcmp(cipher, "none") != 0) {
                error("unsupported cipher %s", cipher);
                free(cipher);
                sshbuf_free(b);
                free(type);
                return NULL;
        }
        free(cipher);

        if (strstr(type, "dsa")) {
                ktype = KEY_DSA;
        } else if (strstr(type, "rsa")) {
                ktype = KEY_RSA;
        } else {
                sshbuf_free(b);
                free(type);
                return NULL;
        }
        if ((key = sshkey_new_private(ktype)) == NULL)
                fatal("key_new_private failed");
        free(type);

        switch (key->type) {
        case KEY_DSA:
                buffer_get_bignum_bits(b, key->dsa->p);
                buffer_get_bignum_bits(b, key->dsa->g);
                buffer_get_bignum_bits(b, key->dsa->q);
                buffer_get_bignum_bits(b, key->dsa->pub_key);
                buffer_get_bignum_bits(b, key->dsa->priv_key);
                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 (!BN_set_word(key->rsa->e, e)) {
                        sshbuf_free(b);
                        sshkey_free(key);
                        return NULL;
                }
                buffer_get_bignum_bits(b, key->rsa->d);
                buffer_get_bignum_bits(b, key->rsa->n);
                buffer_get_bignum_bits(b, key->rsa->iqmp);
                buffer_get_bignum_bits(b, key->rsa->q);
                buffer_get_bignum_bits(b, key->rsa->p);
                if ((r = rsa_generate_additional_parameters(key->rsa)) != 0)
                        fatal("generate RSA parameters failed: %s", ssh_err(r));
                break;
        }
        rlen = sshbuf_len(b);
        if (rlen != 0)
                error("do_convert_private_ssh2_from_blob: "
                    "remaining bytes in key blob %d", rlen);
        sshbuf_free(b);

        /* try the key */
        if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 ||
            sshkey_verify(key, sig, slen, data, sizeof(data), 0) != 0) {
                sshkey_free(key);
                free(sig);
                return NULL;
        }
        free(sig);
        return key;
}

static int
get_line(FILE *fp, char *line, size_t len)
{
        int c;
        size_t pos = 0;

        line[0] = '\0';
        while ((c = fgetc(fp)) != EOF) {
                if (pos >= len - 1)
                        fatal("input line too long.");
                switch (c) {
                case '\r':
                        c = fgetc(fp);
                        if (c != EOF && c != '\n' && ungetc(c, fp) == EOF)
                                fatal("unget: %s", strerror(errno));
                        return pos;
                case '\n':
                        return pos;
                }
                line[pos++] = c;
                line[pos] = '\0';
        }
        /* We reached EOF */
        return -1;
}

static void
do_convert_from_ssh2(struct passwd *pw, struct sshkey **k, int *private)
{
        int r, blen, escaped = 0;
        u_int len;
        char line[1024];
        u_char blob[8096];
        char encoded[8096];
        FILE *fp;

        if ((fp = fopen(identity_file, "r")) == NULL)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
        encoded[0] = '\0';
        while ((blen = get_line(fp, line, sizeof(line))) != -1) {
                if (blen > 0 && line[blen - 1] == '\\')
                        escaped++;
                if (strncmp(line, "----", 4) == 0 ||
                    strstr(line, ": ") != NULL) {
                        if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
                                *private = 1;
                        if (strstr(line, " END ") != NULL) {
                                break;
                        }
                        /* fprintf(stderr, "ignore: %s", line); */
                        continue;
                }
                if (escaped) {
                        escaped--;
                        /* fprintf(stderr, "escaped: %s", line); */
                        continue;
                }
                strlcat(encoded, line, sizeof(encoded));
        }
        len = strlen(encoded);
        if (((len % 4) == 3) &&
            (encoded[len-1] == '=') &&
            (encoded[len-2] == '=') &&
            (encoded[len-3] == '='))
                encoded[len-3] = '\0';
        blen = uudecode(encoded, blob, sizeof(blob));
        if (blen < 0)
                fatal("uudecode failed.");
        if (*private)
                *k = do_convert_private_ssh2_from_blob(blob, blen);
        else if ((r = sshkey_from_blob(blob, blen, k)) != 0)
                fatal("decode blob failed: %s", ssh_err(r));
        fclose(fp);
}

static void
do_convert_from_pkcs8(struct sshkey **k, int *private)
{
        EVP_PKEY *pubkey;
        FILE *fp;

        if ((fp = fopen(identity_file, "r")) == NULL)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
        if ((pubkey = PEM_read_PUBKEY(fp, NULL, NULL, NULL)) == NULL) {
                fatal("%s: %s is not a recognised public key format", __func__,
                    identity_file);
        }
        fclose(fp);
        switch (EVP_PKEY_type(pubkey->type)) {
        case EVP_PKEY_RSA:
                if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
                        fatal("sshkey_new failed");
                (*k)->type = KEY_RSA;
                (*k)->rsa = EVP_PKEY_get1_RSA(pubkey);
                break;
        case EVP_PKEY_DSA:
                if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
                        fatal("sshkey_new failed");
                (*k)->type = KEY_DSA;
                (*k)->dsa = EVP_PKEY_get1_DSA(pubkey);
                break;
#ifdef OPENSSL_HAS_ECC
        case EVP_PKEY_EC:
                if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
                        fatal("sshkey_new failed");
                (*k)->type = KEY_ECDSA;
                (*k)->ecdsa = EVP_PKEY_get1_EC_KEY(pubkey);
                (*k)->ecdsa_nid = sshkey_ecdsa_key_to_nid((*k)->ecdsa);
                break;
#endif
        default:
                fatal("%s: unsupported pubkey type %d", __func__,
                    EVP_PKEY_type(pubkey->type));
        }
        EVP_PKEY_free(pubkey);
        return;
}

static void
do_convert_from_pem(struct sshkey **k, int *private)
{
        FILE *fp;
        RSA *rsa;
#ifdef notyet
        DSA *dsa;
#endif

        if ((fp = fopen(identity_file, "r")) == NULL)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
        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;
        }
#if notyet /* OpenSSH 0.9.8 lacks this function */
        rewind(fp);
        if ((dsa = PEM_read_DSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
                if ((*k = sshkey_new(KEY_UNSPEC)) == NULL)
                        fatal("sshkey_new failed");
                (*k)->type = KEY_DSA;
                (*k)->dsa = dsa;
                fclose(fp);
                return;
        }
        /* XXX ECDSA */
#endif
        fatal("%s: unrecognised raw private key format", __func__);
}

static void
do_convert_from(struct passwd *pw)
{
        struct sshkey *k = NULL;
        int r, private = 0, ok = 0;
        struct stat st;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (stat(identity_file, &st) < 0)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));

        switch (convert_format) {
        case FMT_RFC4716:
                do_convert_from_ssh2(pw, &k, &private);
                break;
        case FMT_PKCS8:
                do_convert_from_pkcs8(&k, &private);
                break;
        case FMT_PEM:
                do_convert_from_pem(&k, &private);
                break;
        default:
                fatal("%s: unknown key format %d", __func__, convert_format);
        }

        if (!private) {
                if ((r = sshkey_write(k, stdout)) == 0)
                        ok = 1;
                if (ok)
                        fprintf(stdout, "\n");
        } else {
                switch (k->type) {
                case KEY_DSA:
                        ok = PEM_write_DSAPrivateKey(stdout, k->dsa, NULL,
                            NULL, 0, NULL, NULL);
                        break;
#ifdef OPENSSL_HAS_ECC
                case KEY_ECDSA:
                        ok = PEM_write_ECPrivateKey(stdout, k->ecdsa, NULL,
                            NULL, 0, NULL, NULL);
                        break;
#endif
                case KEY_RSA:
                        ok = PEM_write_RSAPrivateKey(stdout, k->rsa, NULL,
                            NULL, 0, NULL, NULL);
                        break;
                default:
                        fatal("%s: unsupported key type %s", __func__,
                            sshkey_type(k));
                }
        }

        if (!ok)
                fatal("key write failed");
        sshkey_free(k);
        exit(0);
}
#endif

static void
do_print_public(struct passwd *pw)
{
        struct sshkey *prv;
        struct stat st;
        int r;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (stat(identity_file, &st) < 0)
                fatal("%s: %s", identity_file, strerror(errno));
        prv = load_identity(identity_file);
        if ((r = sshkey_write(prv, stdout)) != 0)
                error("key_write failed: %s", ssh_err(r));
        sshkey_free(prv);
        fprintf(stdout, "\n");
        exit(0);
}

static void
do_download(struct passwd *pw)
{
#ifdef ENABLE_PKCS11
        struct sshkey **keys = NULL;
        int i, nkeys;
        enum sshkey_fp_rep rep;
        int fptype;
        char *fp, *ra;

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

        pkcs11_init(0);
        nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys);
        if (nkeys <= 0)
                fatal("cannot read public key from pkcs11");
        for (i = 0; i < nkeys; i++) {
                if (print_fingerprint) {
                        fp = sshkey_fingerprint(keys[i], fptype, rep);
                        ra = sshkey_fingerprint(keys[i], fingerprint_hash,
                            SSH_FP_RANDOMART);
                        if (fp == NULL || ra == NULL)
                                fatal("%s: sshkey_fingerprint fail", __func__);
                        printf("%u %s %s (PKCS11 key)\n", sshkey_size(keys[i]),
                            fp, sshkey_type(keys[i]));
                        if (log_level >= SYSLOG_LEVEL_VERBOSE)
                                printf("%s\n", ra);
                        free(ra);
                        free(fp);
                } else {
                        (void) sshkey_write(keys[i], stdout); /* XXX check */
                        fprintf(stdout, "\n");
                }
                sshkey_free(keys[i]);
        }
        free(keys);
        pkcs11_terminate();
        exit(0);
#else
        fatal("no pkcs11 support");
#endif /* ENABLE_PKCS11 */
}

static struct sshkey *
try_read_key(char **cpp)
{
        struct sshkey *ret;
        int r;

        if ((ret = sshkey_new(KEY_RSA1)) == NULL)
                fatal("sshkey_new failed");
        /* Try RSA1 */
        if ((r = sshkey_read(ret, cpp)) == 0)
                return ret;
        /* Try modern */
        sshkey_free(ret);
        if ((ret = sshkey_new(KEY_UNSPEC)) == NULL)
                fatal("sshkey_new failed");
        if ((r = sshkey_read(ret, cpp)) == 0)
                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__);
        printf("%u %s %s (%s)\n", sshkey_size(public), fp,
            comment ? comment : "no comment", sshkey_type(public));
        if (log_level >= SYSLOG_LEVEL_VERBOSE)
                printf("%s\n", ra);
        free(ra);
        free(fp);
}

static void
fingerprint_private(const char *path)
{
        struct stat st;
        char *comment = NULL;
        struct sshkey *public = NULL;
        int r;

        if (stat(identity_file, &st) < 0)
                fatal("%s: %s", path, strerror(errno));
        if ((r = sshkey_load_public(path, &public, &comment)) != 0) {
                debug("load public \"%s\": %s", path, ssh_err(r));
                if ((r = sshkey_load_private(path, NULL,
                    &public, &comment)) != 0) {
                        debug("load private \"%s\": %s", path, ssh_err(r));
                        fatal("%s is not a key file.", path);
                }
        }

        fingerprint_one_key(public, comment);
        sshkey_free(public);
        free(comment);
}

static void
do_fingerprint(struct passwd *pw)
{
        FILE *f;
        struct sshkey *public = NULL;
        char *comment = NULL, *cp, *ep, line[SSH_MAX_PUBKEY_BYTES];
        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 (read_keyfile_line(f, path, line, sizeof(line), &lnum) == 0) {
                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) {
                        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);

        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
#ifdef WITH_SSH1
                { "rsa1", "RSA1", _PATH_HOST_KEY_FILE },
#endif /* WITH_SSH1 */
                { "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
                { "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
#ifdef OPENSSL_HAS_ECC
                { "ecdsa", "ECDSA",_PATH_HOST_ECDSA_KEY_FILE },
#endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
                { "ed25519", "ED25519",_PATH_HOST_ED25519_KEY_FILE },
                { NULL, NULL, NULL }
        };

        int first = 0;
        struct stat st;
        struct sshkey *private, *public;
        char comment[1024];
        int i, type, fd, r;
        FILE *f;

        for (i = 0; key_types[i].key_type; i++) {
                if (stat(key_types[i].path, &st) == 0)
                        continue;
                if (errno != ENOENT) {
                        error("Could not stat %s: %s", key_types[i].path,
                            strerror(errno));
                        first = 0;
                        continue;
                }

                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);
                strlcpy(identity_file, key_types[i].path, sizeof(identity_file));
                bits = 0;
                type_bits_valid(type, NULL, &bits);
                if ((r = sshkey_generate(type, bits, &private)) != 0) {
                        error("key_generate failed: %s", ssh_err(r));
                        first = 0;
                        continue;
                }
                if ((r = sshkey_from_private(private, &public)) != 0)
                        fatal("sshkey_from_private failed: %s", ssh_err(r));
                snprintf(comment, sizeof comment, "%s@%s", pw->pw_name,
                    hostname);
                if ((r = sshkey_save_private(private, identity_file, "",
                    comment, use_new_format, new_format_cipher, rounds)) != 0) {
                        error("Saving key \"%s\" failed: %s",
                            identity_file, ssh_err(r));
                        sshkey_free(private);
                        sshkey_free(public);
                        first = 0;
                        continue;
                }
                sshkey_free(private);
                strlcat(identity_file, ".pub", sizeof(identity_file));
                fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
                if (fd == -1) {
                        error("Could not save your public key in %s",
                            identity_file);
                        sshkey_free(public);
                        first = 0;
                        continue;
                }
                f = fdopen(fd, "w");
                if (f == NULL) {
                        error("fdopen %s failed", identity_file);
                        close(fd);
                        sshkey_free(public);
                        first = 0;
                        continue;
                }
                if ((r = sshkey_write(public, f)) != 0) {
                        error("write key failed: %s", ssh_err(r));
                        fclose(f);
                        sshkey_free(public);
                        first = 0;
                        continue;
                }
                fprintf(f, " %s\n", comment);
                fclose(f);
                sshkey_free(public);

        }
        if (first != 0)
                printf("\n");
}

struct known_hosts_ctx {
        const char *host;       /* Hostname searched for in find/delete case */
        FILE *out;              /* Output file, stdout for find_hosts case */
        int has_unhashed;       /* When hashing, original had unhashed hosts */
        int found_key;          /* For find/delete, host was found */
        int invalid;            /* File contained invalid items; don't delete */
};

static int
known_hosts_hash(struct hostkey_foreach_line *l, void *_ctx)
{
        struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
        char *hashed, *cp, *hosts, *ohosts;
        int has_wild = l->hosts && strcspn(l->hosts, "*?!") != strlen(l->hosts);

        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 ((l->match & HKF_MATCH_HOST_HASHED) != 0 ||
                    has_wild || l->marker != MRK_NONE) {
                        fprintf(ctx->out, "%s\n", l->line);
                        if (has_wild && !find_host) {
                                logit("%s:%ld: 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') {
                        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:%ld: invalid line", l->path, l->linenum);
                /* FALLTHROUGH */
        default:
                fprintf(ctx->out, "%s\n", l->line);
                return 0;
        }
        /* NOTREACHED */
        return -1;
}

static int
known_hosts_find_delete(struct hostkey_foreach_line *l, void *_ctx)
{
        struct known_hosts_ctx *ctx = (struct known_hosts_ctx *)_ctx;
        enum sshkey_fp_rep rep;
        int fptype;
        char *fp;

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

        if (l->status == HKF_STATUS_MATCHED) {
                if (delete_host) {
                        if (l->marker != MRK_NONE) {
                                /* Don't remove CA and revocation lines */
                                fprintf(ctx->out, "%s\n", l->line);
                        } else {
                                /*
                                 * Hostname matches and has no CA/revoke
                                 * marker, delete it by *not* writing the
                                 * line to ctx->out.
                                 */
                                ctx->found_key = 1;
                                if (!quiet)
                                        printf("# Host %s found: line %ld\n",
                                            ctx->host, l->linenum);
                        }
                        return 0;
                } else if (find_host) {
                        ctx->found_key = 1;
                        if (!quiet) {
                                printf("# Host %s found: line %ld %s\n",
                                    ctx->host,
                                    l->linenum, l->marker == MRK_CA ? "CA" :
                                    (l->marker == MRK_REVOKE ? "REVOKED" : ""));
                        }
                        if (hash_hosts)
                                known_hosts_hash(l, ctx);
                        else if (print_fingerprint) {
                                fp = sshkey_fingerprint(l->key, fptype, rep);
                                printf("%s %s %s %s\n", ctx->host,
                                    sshkey_type(l->key), fp, l->comment);
                                free(fp);
                        } else
                                fprintf(ctx->out, "%s\n", l->line);
                        return 0;
                }
        } else if (delete_host) {
                /* Retain non-matching hosts when deleting */
                if (l->status == HKF_STATUS_INVALID) {
                        ctx->invalid = 1;
                        logit("%s:%ld: invalid line", l->path, l->linenum);
                }
                fprintf(ctx->out, "%s\n", l->line);
        }
        return 0;
}

static void
do_known_hosts(struct passwd *pw, const char *name)
{
        char *cp, tmp[PATH_MAX], old[PATH_MAX];
        int r, fd, oerrno, inplace = 0;
        struct known_hosts_ctx ctx;
        u_int foreach_options;

        if (!have_identity) {
                cp = tilde_expand_filename(_PATH_SSH_USER_HOSTFILE, pw->pw_uid);
                if (strlcpy(identity_file, cp, sizeof(identity_file)) >=
                    sizeof(identity_file))
                        fatal("Specified known hosts path too long");
                free(cp);
                have_identity = 1;
        }

        memset(&ctx, 0, sizeof(ctx));
        ctx.out = stdout;
        ctx.host = name;

        /*
         * Find hosts goes to stdout, hash and deletions happen in-place
         * A corner case is ssh-keygen -HF foo, which should go to stdout
         */
        if (!find_host && (hash_hosts || delete_host)) {
                if (strlcpy(tmp, identity_file, sizeof(tmp)) >= sizeof(tmp) ||
                    strlcat(tmp, ".XXXXXXXXXX", sizeof(tmp)) >= sizeof(tmp) ||
                    strlcpy(old, identity_file, sizeof(old)) >= sizeof(old) ||
                    strlcat(old, ".old", sizeof(old)) >= sizeof(old))
                        fatal("known_hosts path too long");
                umask(077);
                if ((fd = mkstemp(tmp)) == -1)
                        fatal("mkstemp: %s", strerror(errno));
                if ((ctx.out = fdopen(fd, "w")) == NULL) {
                        oerrno = errno;
                        unlink(tmp);
                        fatal("fdopen: %s", strerror(oerrno));
                }
                inplace = 1;
        }

        /* XXX support identity_file == "-" for stdin */
        foreach_options = find_host ? HKF_WANT_MATCH : 0;
        foreach_options |= print_fingerprint ? HKF_WANT_PARSE_KEY : 0;
        if ((r = hostkeys_foreach(identity_file,
            hash_hosts ? known_hosts_hash : known_hosts_find_delete, &ctx,
            name, NULL, foreach_options)) != 0) {
                if (inplace)
                        unlink(tmp);
                fatal("%s: hostkeys_foreach failed: %s", __func__, ssh_err(r));
        }

        if (inplace)
                fclose(ctx.out);

        if (ctx.invalid) {
                error("%s is not a valid known_hosts file.", identity_file);
                if (inplace) {
                        error("Not replacing existing known_hosts "
                            "file because of errors");
                        unlink(tmp);
                }
                exit(1);
        } else if (delete_host && !ctx.found_key) {
                logit("Host %s not found in %s", name, identity_file);
                if (inplace)
                        unlink(tmp);
        } else if (inplace) {
                /* Backup existing file */
                if (unlink(old) == -1 && errno != ENOENT)
                        fatal("unlink %.100s: %s", old, strerror(errno));
                if (link(identity_file, old) == -1)
                        fatal("link %.100s to %.100s: %s", identity_file, old,
                            strerror(errno));
                /* Move new one into place */
                if (rename(tmp, identity_file) == -1) {
                        error("rename\"%s\" to \"%s\": %s", tmp, identity_file,
                            strerror(errno));
                        unlink(tmp);
                        unlink(old);
                        exit(1);
                }

                printf("%s updated.\n", identity_file);
                printf("Original contents retained as %s\n", old);
                if (ctx.has_unhashed) {
                        logit("WARNING: %s contains unhashed entries", old);
                        logit("Delete this file to ensure privacy "
                            "of hostnames");
                }
        }

        exit (find_host && !ctx.found_key);
}

/*
 * Perform changing a passphrase.  The argument is the passwd structure
 * for the current user.
 */
static void
do_change_passphrase(struct passwd *pw)
{
        char *comment;
        char *old_passphrase, *passphrase1, *passphrase2;
        struct stat st;
        struct sshkey *private;
        int r;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (stat(identity_file, &st) < 0)
                fatal("%s: %s", identity_file, strerror(errno));
        /* Try to load the file with empty passphrase. */
        r = sshkey_load_private(identity_file, "", &private, &comment);
        if (r == SSH_ERR_KEY_WRONG_PASSPHRASE) {
                if (identity_passphrase)
                        old_passphrase = xstrdup(identity_passphrase);
                else
                        old_passphrase =
                            read_passphrase("Enter old passphrase: ",
                            RP_ALLOW_STDIN);
                r = sshkey_load_private(identity_file, old_passphrase,
                    &private, &comment);
                explicit_bzero(old_passphrase, strlen(old_passphrase));
                free(old_passphrase);
                if (r != 0)
                        goto badkey;
        } else if (r != 0) {
 badkey:
                fatal("Failed to load key %s: %s", identity_file, ssh_err(r));
        }
        if (comment)
                printf("Key has comment '%s'\n", comment);

        /* Ask the new passphrase (twice). */
        if (identity_new_passphrase) {
                passphrase1 = xstrdup(identity_new_passphrase);
                passphrase2 = NULL;
        } else {
                passphrase1 =
                        read_passphrase("Enter new passphrase (empty for no "
                            "passphrase): ", RP_ALLOW_STDIN);
                passphrase2 = read_passphrase("Enter same passphrase again: ",
                    RP_ALLOW_STDIN);

                /* Verify that they are the same. */
                if (strcmp(passphrase1, passphrase2) != 0) {
                        explicit_bzero(passphrase1, strlen(passphrase1));
                        explicit_bzero(passphrase2, strlen(passphrase2));
                        free(passphrase1);
                        free(passphrase2);
                        printf("Pass phrases do not match.  Try again.\n");
                        exit(1);
                }
                /* Destroy the other copy. */
                explicit_bzero(passphrase2, strlen(passphrase2));
                free(passphrase2);
        }

        /* Save the file using the new passphrase. */
        if ((r = sshkey_save_private(private, identity_file, passphrase1,
            comment, use_new_format, new_format_cipher, rounds)) != 0) {
                error("Saving key \"%s\" failed: %s.",
                    identity_file, ssh_err(r));
                explicit_bzero(passphrase1, strlen(passphrase1));
                free(passphrase1);
                sshkey_free(private);
                free(comment);
                exit(1);
        }
        /* Destroy the passphrase and the copy of the key in memory. */
        explicit_bzero(passphrase1, strlen(passphrase1));
        free(passphrase1);
        sshkey_free(private);            /* Destroys contents */
        free(comment);

        printf("Your identification has been saved with the new passphrase.\n");
        exit(0);
}

/*
 * Print the SSHFP RR.
 */
static int
do_print_resource_record(struct passwd *pw, char *fname, char *hname)
{
        struct sshkey *public;
        char *comment = NULL;
        struct stat st;
        int r;

        if (fname == NULL)
                fatal("%s: no filename", __func__);
        if (stat(fname, &st) < 0) {
                if (errno == ENOENT)
                        return 0;
                fatal("%s: %s", fname, strerror(errno));
        }
        if ((r = sshkey_load_public(fname, &public, &comment)) != 0)
                fatal("Failed to read v2 public key from \"%s\": %s.",
                    fname, ssh_err(r));
        export_dns_rr(hname, public, stdout, print_generic);
        sshkey_free(public);
        free(comment);
        return 1;
}

/*
 * Change the comment of a private key file.
 */
static void
do_change_comment(struct passwd *pw)
{
        char new_comment[1024], *comment, *passphrase;
        struct sshkey *private;
        struct sshkey *public;
        struct stat st;
        FILE *f;
        int r, fd;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (stat(identity_file, &st) < 0)
                fatal("%s: %s", identity_file, strerror(errno));
        if ((r = sshkey_load_private(identity_file, "",
            &private, &comment)) == 0)
                passphrase = xstrdup("");
        else if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
                fatal("Cannot load private key \"%s\": %s.",
                    identity_file, ssh_err(r));
        else {
                if (identity_passphrase)
                        passphrase = xstrdup(identity_passphrase);
                else if (identity_new_passphrase)
                        passphrase = xstrdup(identity_new_passphrase);
                else
                        passphrase = read_passphrase("Enter passphrase: ",
                            RP_ALLOW_STDIN);
                /* Try to load using the passphrase. */
                if ((r = sshkey_load_private(identity_file, passphrase,
                    &private, &comment)) != 0) {
                        explicit_bzero(passphrase, strlen(passphrase));
                        free(passphrase);
                        fatal("Cannot load private key \"%s\": %s.",
                            identity_file, ssh_err(r));
                }
        }

        if (private->type != KEY_RSA1 && private->type != KEY_ED25519 &&
            !use_new_format) {
                error("Comments are only supported for RSA1 or keys stored in "
                    "the new format (-o).");
                explicit_bzero(passphrase, strlen(passphrase));
                sshkey_free(private);
                exit(1);
        }
        printf("Key now has comment '%s'\n", comment);

        if (identity_comment) {
                strlcpy(new_comment, identity_comment, sizeof(new_comment));
        } else {
                printf("Enter new comment: ");
                fflush(stdout);
                if (!fgets(new_comment, sizeof(new_comment), stdin)) {
                        explicit_bzero(passphrase, strlen(passphrase));
                        sshkey_free(private);
                        exit(1);
                }
                new_comment[strcspn(new_comment, "\n")] = '\0';
        }

        /* Save the file using the new passphrase. */
        if ((r = sshkey_save_private(private, identity_file, passphrase,
            new_comment, use_new_format, new_format_cipher, rounds)) != 0) {
                error("Saving key \"%s\" failed: %s",
                    identity_file, ssh_err(r));
                explicit_bzero(passphrase, strlen(passphrase));
                free(passphrase);
                sshkey_free(private);
                free(comment);
                exit(1);
        }
        explicit_bzero(passphrase, strlen(passphrase));
        free(passphrase);
        if ((r = sshkey_from_private(private, &public)) != 0)
                fatal("key_from_private failed: %s", ssh_err(r));
        sshkey_free(private);

        strlcat(identity_file, ".pub", sizeof(identity_file));
        fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
        if (fd == -1)
                fatal("Could not save your public key in %s", identity_file);
        f = fdopen(fd, "w");
        if (f == NULL)
                fatal("fdopen %s failed: %s", identity_file, strerror(errno));
        if ((r = sshkey_write(public, f)) != 0)
                fatal("write key failed: %s", ssh_err(r));
        sshkey_free(public);
        fprintf(f, " %s\n", new_comment);
        fclose(f);

        free(comment);

        printf("The comment in your key file has been changed.\n");
        exit(0);
}

static void
add_flag_option(struct sshbuf *c, const char *name)
{
        int r;

        debug3("%s: %s", __func__, name);
        if ((r = sshbuf_put_cstring(c, name)) != 0 ||
            (r = sshbuf_put_string(c, NULL, 0)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));
}

static void
add_string_option(struct sshbuf *c, const char *name, const char *value)
{
        struct sshbuf *b;
        int r;

        debug3("%s: %s=%s", __func__, name, value);
        if ((b = sshbuf_new()) == NULL)
                fatal("%s: sshbuf_new failed", __func__);
        if ((r = sshbuf_put_cstring(b, value)) != 0 ||
            (r = sshbuf_put_cstring(c, name)) != 0 ||
            (r = sshbuf_put_stringb(c, b)) != 0)
                fatal("%s: buffer error: %s", __func__, ssh_err(r));

        sshbuf_free(b);
}

#define OPTIONS_CRITICAL        1
#define OPTIONS_EXTENSIONS      2
static void
prepare_options_buf(struct sshbuf *c, int which)
{
        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);
}

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 */
}

static void
do_ca_sign(struct passwd *pw, int argc, char **argv)
{
        int r, i, fd;
        u_int n;
        struct sshkey *ca, *public;
        char valid[64], *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
        FILE *f;

#ifdef ENABLE_PKCS11
        pkcs11_init(1);
#endif
        tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
        if (pkcs11provider != NULL) {
                if ((ca = load_pkcs11_key(tmp)) == NULL)
                        fatal("No PKCS#11 key matching %s found", ca_key_path);
        } else
                ca = load_identity(tmp);
        free(tmp);

        if (key_type_name != NULL &&
            sshkey_type_from_name(key_type_name) != ca->type)  {
                fatal("CA key type %s doesn't match specified %s",
                    sshkey_ssh_name(ca), key_type_name);
        }

        for (i = 0; i < argc; i++) {
                /* Split list of principals */
                n = 0;
                if (cert_principals != NULL) {
                        otmp = tmp = xstrdup(cert_principals);
                        plist = NULL;
                        for (; (cp = strsep(&tmp, ",")) != NULL; n++) {
                                plist = xreallocarray(plist, n + 1, sizeof(*plist));
                                if (*(plist[n] = xstrdup(cp)) == '\0')
                                        fatal("Empty principal name");
                        }
                        free(otmp);
                }
        
                tmp = tilde_expand_filename(argv[i], pw->pw_uid);
                if ((r = sshkey_load_public(tmp, &public, &comment)) != 0)
                        fatal("%s: unable to open \"%s\": %s",
                            __func__, tmp, ssh_err(r));
                if (public->type != KEY_RSA && public->type != KEY_DSA &&
                    public->type != KEY_ECDSA && public->type != KEY_ED25519)
                        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("key_from_private (ca key): %s", ssh_err(r));

                if ((r = sshkey_certify(public, ca, key_type_name)) != 0)
                        fatal("Couldn't certify key %s: %s", tmp, ssh_err(r));

                if ((cp = strrchr(tmp, '.')) != NULL && strcmp(cp, ".pub") == 0)
                        *cp = '\0';
                xasprintf(&out, "%s-cert.pub", tmp);
                free(tmp);

                if ((fd = open(out, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
                        fatal("Could not open \"%s\" for writing: %s", out,
                            strerror(errno));
                if ((f = fdopen(fd, "w")) == NULL)
                        fatal("%s: fdopen: %s", __func__, strerror(errno));
                if ((r = sshkey_write(public, f)) != 0)
                        fatal("Could not write certified key to %s: %s",
                            out, ssh_err(r));
                fprintf(f, " %s\n", comment);
                fclose(f);

                if (!quiet) {
                        sshkey_format_cert_validity(public->cert,
                            valid, sizeof(valid));
                        logit("Signed %s key %s: id \"%s\" serial %llu%s%s "
                            "valid %s", sshkey_cert_type(public),
                            out, public->cert->key_id,
                            (unsigned long long)public->cert->serial,
                            cert_principals != NULL ? " for " : "",
                            cert_principals != NULL ? cert_principals : "",
                            valid);
                }

                sshkey_free(public);
                free(out);
        }
#ifdef ENABLE_PKCS11
        pkcs11_terminate();
#endif
        exit(0);
}

static u_int64_t
parse_relative_time(const char *s, time_t now)
{
        int64_t mul, secs;

        mul = *s == '-' ? -1 : 1;

        if ((secs = convtime(s + 1)) == -1)
                fatal("Invalid relative certificate time %s", s);
        if (mul == -1 && secs > now)
                fatal("Certificate time %s cannot be represented", s);
        return now + (u_int64_t)(secs * mul);
}

static u_int64_t
parse_absolute_time(const char *s)
{
        struct tm tm;
        time_t tt;
        char buf[32], *fmt;

        /*
         * POSIX strptime says "The application shall ensure that there
         * is white-space or other non-alphanumeric characters between
         * any two conversion specifications" so arrange things this way.
         */
        switch (strlen(s)) {
        case 8:
                fmt = "%Y-%m-%d";
                snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6);
                break;
        case 14:
                fmt = "%Y-%m-%dT%H:%M:%S";
                snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s",
                    s, s + 4, s + 6, s + 8, s + 10, s + 12);
                break;
        default:
                fatal("Invalid certificate time format %s", s);
        }

        memset(&tm, 0, sizeof(tm));
        if (strptime(buf, fmt, &tm) == NULL)
                fatal("Invalid certificate time %s", s);
        if ((tt = mktime(&tm)) < 0)
                fatal("Certificate time %s cannot be represented", s);
        return (u_int64_t)tt;
}

static void
parse_cert_times(char *timespec)
{
        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
         *   to := [+-]timespec | YYYYMMDD | YYYYMMDDHHMMSS
         */
        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
                cert_valid_from = parse_absolute_time(from);

        if (*to == '-' || *to == '+')
                cert_valid_to = parse_relative_time(to, now);
        else
                cert_valid_to = parse_absolute_time(to);

        if (cert_valid_to <= cert_valid_from)
                fatal("Empty certificate validity interval");
        free(from);
}

static void
add_cert_option(char *opt)
{
        char *val;

        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
                fatal("Unsupported certificate option \"%s\"", opt);
}

static void
show_options(struct sshbuf *optbuf, int in_critical)
{
        char *name, *arg;
        struct sshbuf *options, *option = NULL;
        int r;

        if ((options = sshbuf_fromb(optbuf)) == NULL)
                fatal("%s: sshbuf_fromb failed", __func__);
        while (sshbuf_len(options) != 0) {
                sshbuf_free(option);
                option = NULL;
                if ((r = sshbuf_get_cstring(options, &name, NULL)) != 0 ||
                    (r = sshbuf_froms(options, &option)) != 0)
                        fatal("%s: buffer error: %s", __func__, ssh_err(r));
                printf("                %s", name);
                if (!in_critical &&
                    (strcmp(name, "permit-X11-forwarding") == 0 ||
                    strcmp(name, "permit-agent-forwarding") == 0 ||
                    strcmp(name, "permit-port-forwarding") == 0 ||
                    strcmp(name, "permit-pty") == 0 ||
                    strcmp(name, "permit-user-rc") == 0))
                        printf("\n");
                else if (in_critical &&
                    (strcmp(name, "force-command") == 0 ||
                    strcmp(name, "source-address") == 0)) {
                        if ((r = sshbuf_get_cstring(option, &arg, NULL)) != 0)
                                fatal("%s: buffer error: %s",
                                    __func__, ssh_err(r));
                        printf(" %s\n", arg);
                        free(arg);
                } else {
                        printf(" UNKNOWN OPTION (len %zu)\n",
                            sshbuf_len(option));
                        sshbuf_reset(option);
                }
                free(name);
                if (sshbuf_len(option) != 0)
                        fatal("Option corrupt: extra data at end");
        }
        sshbuf_free(option);
        sshbuf_free(options);
}

static void
print_cert(struct sshkey *key)
{
        char valid[64], *key_fp, *ca_fp;
        u_int i;

        key_fp = sshkey_fingerprint(key, fingerprint_hash, SSH_FP_DEFAULT);
        ca_fp = sshkey_fingerprint(key->cert->signature_key,
            fingerprint_hash, SSH_FP_DEFAULT);
        if (key_fp == NULL || ca_fp == NULL)
                fatal("%s: sshkey_fingerprint fail", __func__);
        sshkey_format_cert_validity(key->cert, valid, sizeof(valid));

        printf("        Type: %s %s certificate\n", sshkey_ssh_name(key),
            sshkey_cert_type(key));
        printf("        Public key: %s %s\n", sshkey_type(key), key_fp);
        printf("        Signing CA: %s %s\n",
            sshkey_type(key->cert->signature_key), ca_fp);
        printf("        Key ID: \"%s\"\n", key->cert->key_id);
        printf("        Serial: %llu\n", (unsigned long long)key->cert->serial);
        printf("        Valid: %s\n", valid);
        printf("        Principals: ");
        if (key->cert->nprincipals == 0)
                printf("(none)\n");
        else {
                for (i = 0; i < key->cert->nprincipals; i++)
                        printf("\n                %s",
                            key->cert->principals[i]);
                printf("\n");
        }
        printf("        Critical Options: ");
        if (sshbuf_len(key->cert->critical) == 0)
                printf("(none)\n");
        else {
                printf("\n");
                show_options(key->cert->critical, 1);
        }
        printf("        Extensions: ");
        if (sshbuf_len(key->cert->extensions) == 0)
                printf("(none)\n");
        else {
                printf("\n");
                show_options(key->cert->extensions, 0);
        }
}

static void
do_show_cert(struct passwd *pw)
{
        struct sshkey *key = NULL;
        struct stat st;
        int r, is_stdin = 0, ok = 0;
        FILE *f;
        char *cp, line[SSH_MAX_PUBKEY_BYTES];
        const char *path;
        u_long lnum = 0;

        if (!have_identity)
                ask_filename(pw, "Enter file in which the key is");
        if (strcmp(identity_file, "-") != 0 && stat(identity_file, &st) < 0)
                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));

        path = identity_file;
        if (strcmp(path, "-") == 0) {
                f = stdin;
                path = "(stdin)";
                is_stdin = 1;
        } else if ((f = fopen(identity_file, "r")) == NULL)
                fatal("fopen %s: %s", identity_file, strerror(errno));

        while (read_keyfile_line(f, path, line, sizeof(line), &lnum) == 0) {
                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("key_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);
        }
        sshkey_free(key);
        fclose(f);
        exit(ok ? 0 : 1);
}

static void
load_krl(const char *path, struct ssh_krl **krlp)
{
        struct sshbuf *krlbuf;
        int r, fd;

        if ((krlbuf = sshbuf_new()) == NULL)
                fatal("sshbuf_new failed");
        if ((fd = open(path, O_RDONLY)) == -1)
                fatal("open %s: %s", path, strerror(errno));
        if ((r = sshkey_load_file(fd, krlbuf)) != 0)
                fatal("Unable to load KRL: %s", ssh_err(r));
        close(fd);
        /* XXX check sigs */
        if ((r = ssh_krl_from_blob(krlbuf, krlp, NULL, 0)) != 0 ||
            *krlp == NULL)
                fatal("Invalid KRL file: %s", ssh_err(r));
        sshbuf_free(krlbuf);
}

static void
update_krl_from_file(struct passwd *pw, const char *file, int wild_ca,
    const struct sshkey *ca, struct ssh_krl *krl)
{
        struct sshkey *key = NULL;
        u_long lnum = 0;
        char *path, *cp, *ep, line[SSH_MAX_PUBKEY_BYTES];
        unsigned long long serial, serial2;
        int i, was_explicit_key, was_sha1, 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 (read_keyfile_line(krl_spec, path, line, sizeof(line),
            &lnum) == 0) {
                was_explicit_key = was_sha1 = 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, "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 {
                                /*
                                 * Just try to process the line as a key.
                                 * Parsing will fail if it isn't.
                                 */
                        }
                        if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
                                fatal("key_new");
                        if ((r = sshkey_read(key, &cp)) != 0)
                                fatal("%s:%lu: invalid key: %s",
                                    path, lnum, ssh_err(r));
                        if (was_explicit_key)
                                r = ssh_krl_revoke_key_explicit(krl, key);
                        else if (was_sha1)
                                r = ssh_krl_revoke_key_sha1(krl, key);
                        else
                                r = ssh_krl_revoke_key(krl, key);
                        if (r != 0)
                                fatal("%s: revoke key failed: %s",
                                    __func__, ssh_err(r));
                        sshkey_free(key);
                }
        }
        if (strcmp(path, "-") != 0)
                fclose(krl_spec);
        free(path);
}

static void
do_gen_krl(struct passwd *pw, int updating, int argc, char **argv)
{
        struct ssh_krl *krl;
        struct stat sb;
        struct sshkey *ca = NULL;
        int fd, i, r, wild_ca = 0;
        char *tmp;
        struct sshbuf *kbuf;

        if (*identity_file == '\0')
                fatal("KRL generation requires an output file");
        if (stat(identity_file, &sb) == -1) {
                if (errno != ENOENT)
                        fatal("Cannot access KRL \"%s\": %s",
                            identity_file, strerror(errno));
                if (updating)
                        fatal("KRL \"%s\" does not exist", identity_file);
        }
        if (ca_key_path != NULL) {
                if (strcasecmp(ca_key_path, "none") == 0)
                        wild_ca = 1;
                else {
                        tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
                        if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
                                fatal("Cannot load CA public key %s: %s",
                                    tmp, ssh_err(r));
                        free(tmp);
                }
        }

        if (updating)
                load_krl(identity_file, &krl);
        else if ((krl = ssh_krl_init()) == NULL)
                fatal("couldn't create KRL");

        if (cert_serial != 0)
                ssh_krl_set_version(krl, cert_serial);
        if (identity_comment != NULL)
                ssh_krl_set_comment(krl, identity_comment);

        for (i = 0; i < argc; i++)
                update_krl_from_file(pw, argv[i], wild_ca, ca, krl);

        if ((kbuf = sshbuf_new()) == NULL)
                fatal("sshbuf_new failed");
        if (ssh_krl_to_blob(krl, kbuf, NULL, 0) != 0)
                fatal("Couldn't generate KRL");
        if ((fd = open(identity_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
                fatal("open %s: %s", identity_file, strerror(errno));
        if (atomicio(vwrite, fd, (void *)sshbuf_ptr(kbuf), sshbuf_len(kbuf)) !=
            sshbuf_len(kbuf))
                fatal("write %s: %s", identity_file, strerror(errno));
        close(fd);
        sshbuf_free(kbuf);
        ssh_krl_free(krl);
        sshkey_free(ca);
}

static void
do_check_krl(struct passwd *pw, int argc, char **argv)
{
        int i, r, ret = 0;
        char *comment;
        struct ssh_krl *krl;
        struct sshkey *k;

        if (*identity_file == '\0')
                fatal("KRL checking requires an input file");
        load_krl(identity_file, &krl);
        for (i = 0; i < argc; i++) {
                if ((r = sshkey_load_public(argv[i], &k, &comment)) != 0)
                        fatal("Cannot load public key %s: %s",
                            argv[i], ssh_err(r));
                r = ssh_krl_check_key(krl, k);
                printf("%s%s%s%s: %s\n", argv[i],
                    *comment ? " (" : "", comment, *comment ? ")" : "",
                    r == 0 ? "ok" : "REVOKED");
                if (r != 0)
                        ret = 1;
                sshkey_free(k);
                free(comment);
        }
        ssh_krl_free(krl);
        exit(ret);
}

static void
usage(void)
{
        fprintf(stderr,
            "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa | rsa1]\n"
            "                  [-N new_passphrase] [-C comment] [-f output_keyfile]\n"
            "       ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile]\n"
            "       ssh-keygen -i [-m key_format] [-f input_keyfile]\n"
            "       ssh-keygen -e [-m key_format] [-f input_keyfile]\n"
            "       ssh-keygen -y [-f input_keyfile]\n"
            "       ssh-keygen -c [-P passphrase] [-C comment] [-f keyfile]\n"
            "       ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]\n"
            "       ssh-keygen -B [-f input_keyfile]\n");
#ifdef ENABLE_PKCS11
        fprintf(stderr,
            "       ssh-keygen -D pkcs11\n");
#endif
        fprintf(stderr,
            "       ssh-keygen -F hostname [-f known_hosts_file] [-l]\n"
            "       ssh-keygen -H [-f known_hosts_file]\n"
            "       ssh-keygen -R hostname [-f known_hosts_file]\n"
            "       ssh-keygen -r hostname [-f input_keyfile] [-g]\n"
#ifdef WITH_OPENSSL
            "       ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]\n"
            "       ssh-keygen -T output_file -f input_file [-v] [-a rounds] [-J num_lines]\n"
            "                  [-j start_line] [-K checkpt] [-W generator]\n"
#endif
            "       ssh-keygen -s ca_key -I certificate_identity [-h] [-n principals]\n"
            "                  [-O option] [-V validity_interval] [-z serial_number] file ...\n"
            "       ssh-keygen -L [-f input_keyfile]\n"
            "       ssh-keygen -A\n"
            "       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]\n"
            "                  file ...\n"
            "       ssh-keygen -Q -f krl_file file ...\n");
        exit(1);
}

/*
 * Main program for key management.
 */
int
main(int argc, char **argv)
{
        char dotsshdir[PATH_MAX], comment[1024], *passphrase1, *passphrase2;
        char *rr_hostname = NULL, *ep, *fp, *ra;
        struct sshkey *private, *public;
        struct passwd *pw;
        struct stat st;
        int r, opt, type, fd;
        int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
        FILE *f;
        const char *errstr;
#ifdef WITH_OPENSSL
        /* Moduli generation/screening */
        char out_file[PATH_MAX], *checkpoint = NULL;
        u_int32_t memory = 0, generator_wanted = 0;
        int do_gen_candidates = 0, do_screen_candidates = 0;
        unsigned long start_lineno = 0, lines_to_process = 0;
        BIGNUM *start = NULL;
#endif

        extern int optind;
        extern char *optarg;

        ssh_malloc_init();      /* must be called before any mallocs */
        /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
        sanitise_stdfd();

        __progname = ssh_get_progname(argv[0]);

#ifdef WITH_OPENSSL
        OpenSSL_add_all_algorithms();
#endif
        log_init(argv[0], SYSLOG_LEVEL_INFO, SYSLOG_FACILITY_USER, 1);

        seed_rng();

        /* we need this for the home * directory.  */
        pw = getpwuid(getuid());
        if (!pw)
                fatal("No user exists for uid %lu", (u_long)getuid());
        if (gethostname(hostname, sizeof(hostname)) < 0)
                fatal("gethostname: %s", strerror(errno));

        /* Remaining characters: UYdw */
        while ((opt = getopt(argc, argv, "ABHLQXceghiklopquvxy"
            "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Z:"
            "a:b:f:g:j:m:n:r:s:t:z:")) != -1) {
                switch (opt) {
                case 'A':
                        gen_all_hostkeys = 1;
                        break;
                case 'b':
                        bits = (u_int32_t)strtonum(optarg, 256, 32768, &errstr);
                        if (errstr)
                                fatal("Bits has bad value %s (%s)",
                                        optarg, errstr);
                        break;
                case 'E':
                        fingerprint_hash = ssh_digest_alg_by_name(optarg);
                        if (fingerprint_hash == -1)
                                fatal("Invalid hash algorithm \"%s\"", optarg);
                        break;
                case 'F':
                        find_host = 1;
                        rr_hostname = optarg;
                        break;
                case 'H':
                        hash_hosts = 1;
                        break;
                case 'I':
                        cert_key_id = optarg;
                        break;
                case 'R':
                        delete_host = 1;
                        rr_hostname = optarg;
                        break;
                case 'L':
                        show_cert = 1;
                        break;
                case 'l':
                        print_fingerprint = 1;
                        break;
                case 'B':
                        print_bubblebabble = 1;
                        break;
                case 'm':
                        if (strcasecmp(optarg, "RFC4716") == 0 ||
                            strcasecmp(optarg, "ssh2") == 0) {
                                convert_format = FMT_RFC4716;
                                break;
                        }
                        if (strcasecmp(optarg, "PKCS8") == 0) {
                                convert_format = FMT_PKCS8;
                                break;
                        }
                        if (strcasecmp(optarg, "PEM") == 0) {
                                convert_format = FMT_PEM;
                                break;
                        }
                        fatal("Unsupported conversion format \"%s\"", optarg);
                case 'n':
                        cert_principals = optarg;
                        break;
                case 'o':
                        use_new_format = 1;
                        break;
                case 'p':
                        change_passphrase = 1;
                        break;
                case 'c':
                        change_comment = 1;
                        break;
                case 'f':
                        if (strlcpy(identity_file, optarg,
                            sizeof(identity_file)) >= sizeof(identity_file))
                                fatal("Identity filename too long");
                        have_identity = 1;
                        break;
                case 'g':
                        print_generic = 1;
                        break;
                case 'P':
                        identity_passphrase = optarg;
                        break;
                case 'N':
                        identity_new_passphrase = optarg;
                        break;
                case 'Q':
                        check_krl = 1;
                        break;
                case 'O':
                        add_cert_option(optarg);
                        break;
                case 'Z':
                        new_format_cipher = optarg;
                        break;
                case 'C':
                        identity_comment = optarg;
                        break;
                case 'q':
                        quiet = 1;
                        break;
                case 'e':
                case 'x':
                        /* export key */
                        convert_to = 1;
                        break;
                case 'h':
                        cert_key_type = SSH2_CERT_TYPE_HOST;
                        certflags_flags = 0;
                        break;
                case 'k':
                        gen_krl = 1;
                        break;
                case 'i':
                case 'X':
                        /* import key */
                        convert_from = 1;
                        break;
                case 'y':
                        print_public = 1;
                        break;
                case 's':
                        ca_key_path = optarg;
                        break;
                case 't':
                        key_type_name = optarg;
                        break;
                case 'D':
                        pkcs11provider = optarg;
                        break;
                case 'u':
                        update_krl = 1;
                        break;
                case 'v':
                        if (log_level == SYSLOG_LEVEL_INFO)
                                log_level = SYSLOG_LEVEL_DEBUG1;
                        else {
                                if (log_level >= SYSLOG_LEVEL_DEBUG1 &&
                                    log_level < SYSLOG_LEVEL_DEBUG3)
                                        log_level++;
                        }
                        break;
                case 'r':
                        rr_hostname = optarg;
                        break;
                case 'a':
                        rounds = (int)strtonum(optarg, 1, INT_MAX, &errstr);
                        if (errstr)
                                fatal("Invalid number: %s (%s)",
                                        optarg, errstr);
                        break;
                case 'V':
                        parse_cert_times(optarg);
                        break;
                case 'z':
                        errno = 0;
                        cert_serial = strtoull(optarg, &ep, 10);
                        if (*optarg < '0' || *optarg > '9' || *ep != '\0' ||
                            (errno == ERANGE && cert_serial == ULLONG_MAX))
                                fatal("Invalid serial number \"%s\"", optarg);
                        break;
#ifdef WITH_OPENSSL
                /* Moduli generation/screening */
                case 'W':
                        generator_wanted = (u_int32_t)strtonum(optarg, 1,
                            UINT_MAX, &errstr);
                        if (errstr)
                                fatal("Desired generator has bad value: %s (%s)",
                                        optarg, errstr);
                        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 'G':
                        do_gen_candidates = 1;
                        if (strlcpy(out_file, optarg, sizeof(out_file)) >=
                            sizeof(out_file))
                                fatal("Output filename too long");
                        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 'K':
                        if (strlen(optarg) >= PATH_MAX)
                                fatal("Checkpoint filename too long");
                        checkpoint = xstrdup(optarg);
                        break;
                case 'S':
                        /* XXX - also compare length against bits */
                        if (BN_hex2bn(&start, optarg) == 0)
                                fatal("Invalid start point.");
                        break;
#endif /* WITH_OPENSSL */
                case '?':
                default:
                        usage();
                }
        }

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

        argv += optind;
        argc -= optind;

        if (ca_key_path != NULL) {
                if (argc < 1 && !gen_krl) {
                        error("Too few arguments.");
                        usage();
                }
        } else if (argc > 0 && !gen_krl && !check_krl) {
                error("Too many arguments.");
                usage();
        }
        if (change_passphrase && change_comment) {
                error("Can only have one of -p and -c.");
                usage();
        }
        if (print_fingerprint && (delete_host || hash_hosts)) {
                error("Cannot use -l with -H or -R.");
                usage();
        }
        if (gen_krl) {
                do_gen_krl(pw, update_krl, argc, argv);
                return (0);
        }
        if (check_krl) {
                do_check_krl(pw, argc, argv);
                return (0);
        }
        if (ca_key_path != NULL) {
                if (cert_key_id == NULL)
                        fatal("Must specify key id (-I) when certifying");
                do_ca_sign(pw, argc, argv);
        }
        if (show_cert)
                do_show_cert(pw);
        if (delete_host || hash_hosts || find_host)
                do_known_hosts(pw, rr_hostname);
        if (pkcs11provider != NULL)
                do_download(pw);
        if (print_fingerprint || print_bubblebabble)
                do_fingerprint(pw);
        if (change_passphrase)
                do_change_passphrase(pw);
        if (change_comment)
                do_change_comment(pw);
#ifdef WITH_OPENSSL
        if (convert_to)
                do_convert_to(pw);
        if (convert_from)
                do_convert_from(pw);
#endif
        if (print_public)
                do_print_public(pw);
        if (rr_hostname != NULL) {
                unsigned int n = 0;

                if (have_identity) {
                        n = do_print_resource_record(pw,
                            identity_file, rr_hostname);
                        if (n == 0)
                                fatal("%s: %s", identity_file, strerror(errno));
                        exit(0);
                } else {

                        n += do_print_resource_record(pw,
                            _PATH_HOST_RSA_KEY_FILE, rr_hostname);
                        n += do_print_resource_record(pw,
                            _PATH_HOST_DSA_KEY_FILE, rr_hostname);
                        n += do_print_resource_record(pw,
                            _PATH_HOST_ECDSA_KEY_FILE, rr_hostname);
                        n += do_print_resource_record(pw,
                            _PATH_HOST_ED25519_KEY_FILE, rr_hostname);
                        if (n == 0)
                                fatal("no keys found.");
                        exit(0);
                }
        }

#ifdef WITH_OPENSSL
        if (do_gen_candidates) {
                FILE *out = fopen(out_file, "w");

                if (out == NULL) {
                        error("Couldn't open modulus candidate file \"%s\": %s",
                            out_file, strerror(errno));
                        return (1);
                }
                if (bits == 0)
                        bits = DEFAULT_BITS;
                if (gen_candidates(out, memory, bits, start) != 0)
                        fatal("modulus candidate generation failed");

                return (0);
        }

        if (do_screen_candidates) {
                FILE *in;
                FILE *out = fopen(out_file, "a");

                if (have_identity && strcmp(identity_file, "-") != 0) {
                        if ((in = fopen(identity_file, "r")) == NULL) {
                                fatal("Couldn't open modulus candidate "
                                    "file \"%s\": %s", identity_file,
                                    strerror(errno));
                        }
                } else
                        in = stdin;

                if (out == NULL) {
                        fatal("Couldn't open moduli file \"%s\": %s",
                            out_file, strerror(errno));
                }
                if (prime_test(in, out, rounds == 0 ? 100 : rounds,
                    generator_wanted, checkpoint,
                    start_lineno, lines_to_process) != 0)
                        fatal("modulus screening failed");
                return (0);
        }
#endif

        if (gen_all_hostkeys) {
                do_gen_all_hostkeys(pw);
                return (0);
        }

        if (key_type_name == NULL)
                key_type_name = DEFAULT_KEY_TYPE_NAME;

        type = sshkey_type_from_name(key_type_name);
        type_bits_valid(type, key_type_name, &bits);

        if (!quiet)
                printf("Generating public/private %s key pair.\n",
                    key_type_name);
        if ((r = sshkey_generate(type, bits, &private)) != 0)
                fatal("key_generate failed");
        if ((r = sshkey_from_private(private, &public)) != 0)
                fatal("key_from_private failed: %s\n", ssh_err(r));

        if (!have_identity)
                ask_filename(pw, "Enter file in which to save the key");

        /* Create ~/.ssh directory if it doesn't already exist. */
        snprintf(dotsshdir, sizeof dotsshdir, "%s/%s",
            pw->pw_dir, _PATH_SSH_USER_DIR);
        if (strstr(identity_file, dotsshdir) != NULL) {
                if (stat(dotsshdir, &st) < 0) {
                        if (errno != ENOENT) {
                                error("Could not stat %s: %s", dotsshdir,
                                    strerror(errno));
                        } else if (mkdir(dotsshdir, 0700) < 0) {
                                error("Could not create directory '%s': %s",
                                    dotsshdir, strerror(errno));
                        } else if (!quiet)
                                printf("Created directory '%s'.\n", dotsshdir);
                }
        }
        /* If the file already exists, ask the user to confirm. */
        if (stat(identity_file, &st) >= 0) {
                char yesno[3];
                printf("%s already exists.\n", identity_file);
                printf("Overwrite (y/n)? ");
                fflush(stdout);
                if (fgets(yesno, sizeof(yesno), stdin) == NULL)
                        exit(1);
                if (yesno[0] != 'y' && yesno[0] != 'Y')
                        exit(1);
        }
        /* Ask for a passphrase (twice). */
        if (identity_passphrase)
                passphrase1 = xstrdup(identity_passphrase);
        else if (identity_new_passphrase)
                passphrase1 = xstrdup(identity_new_passphrase);
        else {
passphrase_again:
                passphrase1 =
                        read_passphrase("Enter passphrase (empty for no "
                            "passphrase): ", RP_ALLOW_STDIN);
                passphrase2 = read_passphrase("Enter same passphrase again: ",
                    RP_ALLOW_STDIN);
                if (strcmp(passphrase1, passphrase2) != 0) {
                        /*
                         * The passphrases do not match.  Clear them and
                         * retry.
                         */
                        explicit_bzero(passphrase1, strlen(passphrase1));
                        explicit_bzero(passphrase2, strlen(passphrase2));
                        free(passphrase1);
                        free(passphrase2);
                        printf("Passphrases do not match.  Try again.\n");
                        goto passphrase_again;
                }
                /* Clear the other copy of the passphrase. */
                explicit_bzero(passphrase2, strlen(passphrase2));
                free(passphrase2);
        }

        if (identity_comment) {
                strlcpy(comment, identity_comment, sizeof(comment));
        } else {
                /* Create default comment field for the passphrase. */
                snprintf(comment, sizeof comment, "%s@%s", pw->pw_name, hostname);
        }

        /* Save the key with the given passphrase and comment. */
        if ((r = sshkey_save_private(private, identity_file, passphrase1,
            comment, use_new_format, new_format_cipher, rounds)) != 0) {
                error("Saving key \"%s\" failed: %s",
                    identity_file, ssh_err(r));
                explicit_bzero(passphrase1, strlen(passphrase1));
                free(passphrase1);
                exit(1);
        }
        /* Clear the passphrase. */
        explicit_bzero(passphrase1, strlen(passphrase1));
        free(passphrase1);

        /* Clear the private key and the random number generator. */
        sshkey_free(private);

        if (!quiet)
                printf("Your identification has been saved in %s.\n", identity_file);

        strlcat(identity_file, ".pub", sizeof(identity_file));
        if ((fd = open(identity_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
                fatal("Unable to save public key to %s: %s",
                    identity_file, strerror(errno));
        if ((f = fdopen(fd, "w")) == NULL)
                fatal("fdopen %s failed: %s", identity_file, strerror(errno));
        if ((r = sshkey_write(public, f)) != 0)
                error("write key failed: %s", ssh_err(r));
        fprintf(f, " %s\n", comment);
        fclose(f);

        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);
}