1 files changed, 603 insertions, 225 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 8c829cad6..0d6ed1fff 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.355 2019/10/03 17:07:50 jmc Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.398 2020/02/07 03:27:54 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -63,6 +63,8 @@
 #include "utf8.h"
 #include "authfd.h"
 #include "sshsig.h"
+#include "ssh-sk.h"
+#include "sk-api.h" /* XXX for SSH_SK_USER_PRESENCE_REQD; remove */
 
 #ifdef WITH_OPENSSL
 # define DEFAULT_KEY_TYPE_NAME "rsa"
@@ -118,11 +120,12 @@ static u_int64_t cert_valid_from = 0;
 static u_int64_t cert_valid_to = ~0ULL;
 
 /* Certificate options */
-#define CERTOPT_X_FWD   (1)
-#define CERTOPT_AGENT_FWD       (1<<1)
-#define CERTOPT_PORT_FWD        (1<<2)
-#define CERTOPT_PTY             (1<<3)
-#define CERTOPT_USER_RC (1<<4)
+#define CERTOPT_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_NO_REQUIRE_USER_PRESENCE        (1<<5)
 #define CERTOPT_DEFAULT (CERTOPT_X_FWD|CERTOPT_AGENT_FWD| \
                          CERTOPT_PORT_FWD|CERTOPT_PTY|CERTOPT_USER_RC)
 static u_int32_t certflags_flags = CERTOPT_DEFAULT;
@@ -150,16 +153,16 @@ static char *key_type_name = NULL;
 /* Load key from this PKCS#11 provider */
 static char *pkcs11provider = NULL;
 
+/* FIDO/U2F provider to use */
+static char *sk_provider = NULL;
+
 /* Format for writing private keys */
 static int private_key_format = SSHKEY_PRIVATE_OPENSSH;
 
 /* Cipher for new-format private keys */
 static char *openssh_format_cipher = NULL;
 
-/*
- * Number of KDF rounds to derive new format keys /
- * number of primality trials when screening moduli.
- */
+/* Number of KDF rounds to derive new format keys. */
 static int rounds = 0;
 
 /* argv0 */
@@ -269,6 +272,10 @@ ask_filename(struct passwd *pw, const char *prompt)
                 case KEY_ECDSA:
                         name = _PATH_SSH_CLIENT_ID_ECDSA;
                         break;
+                case KEY_ECDSA_SK_CERT:
+                case KEY_ECDSA_SK:
+                        name = _PATH_SSH_CLIENT_ID_ECDSA_SK;
+                        break;
 #endif
                 case KEY_RSA_CERT:
                 case KEY_RSA:
@@ -278,6 +285,10 @@ ask_filename(struct passwd *pw, const char *prompt)
                 case KEY_ED25519_CERT:
                         name = _PATH_SSH_CLIENT_ID_ED25519;
                         break;
+                case KEY_ED25519_SK:
+                case KEY_ED25519_SK_CERT:
+                        name = _PATH_SSH_CLIENT_ID_ED25519_SK;
+                        break;
                 case KEY_XMSS:
                 case KEY_XMSS_CERT:
                         name = _PATH_SSH_CLIENT_ID_XMSS;
@@ -391,6 +402,16 @@ do_convert_to_pem(struct sshkey *k)
                 if (!PEM_write_RSAPublicKey(stdout, k->rsa))
                         fatal("PEM_write_RSAPublicKey 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));
         }
@@ -568,8 +589,10 @@ do_convert_private_ssh2(struct sshbuf *b)
                 error("%s: remaining bytes in key blob %d", __func__, rlen);
 
         /* try the key */
-        if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 ||
-            sshkey_verify(key, sig, slen, data, sizeof(data), NULL, 0) != 0) {
+        if (sshkey_sign(key, &sig, &slen, data, sizeof(data),
+            NULL, NULL, 0) != 0 ||
+            sshkey_verify(key, sig, slen, data, sizeof(data),
+            NULL, 0, NULL) != 0) {
                 sshkey_free(key);
                 free(sig);
                 return NULL;
@@ -651,6 +674,7 @@ do_convert_from_ssh2(struct passwd *pw, struct sshkey **k, int *private)
                 *k = do_convert_private_ssh2(buf);
         else if ((r = sshkey_fromb(buf, k)) != 0)
                 fatal("decode blob failed: %s", ssh_err(r));
+        sshbuf_free(buf);
         fclose(fp);
 }
 
@@ -807,13 +831,13 @@ do_download(struct passwd *pw)
         int i, nkeys;
         enum sshkey_fp_rep rep;
         int fptype;
-        char *fp, *ra;
+        char *fp, *ra, **comments = NULL;
 
         fptype = print_bubblebabble ? SSH_DIGEST_SHA1 : fingerprint_hash;
         rep =    print_bubblebabble ? SSH_FP_BUBBLEBABBLE : SSH_FP_DEFAULT;
 
         pkcs11_init(1);
-        nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys);
+        nkeys = pkcs11_add_provider(pkcs11provider, NULL, &keys, &comments);
         if (nkeys <= 0)
                 fatal("cannot read public key from pkcs11");
         for (i = 0; i < nkeys; i++) {
@@ -831,10 +855,13 @@ do_download(struct passwd *pw)
                         free(fp);
                 } else {
                         (void) sshkey_write(keys[i], stdout); /* XXX check */
-                        fprintf(stdout, "\n");
+                        fprintf(stdout, "%s%s\n",
+                            *(comments[i]) == '\0' ? "" : " ", comments[i]);
                 }
+                free(comments[i]);
                 sshkey_free(keys[i]);
         }
+        free(comments);
         free(keys);
         pkcs11_terminate();
         exit(0);
@@ -1247,8 +1274,10 @@ known_hosts_find_delete(struct hostkey_foreach_line *l, void *_ctx)
                                 if (fp == NULL || ra == NULL)
                                         fatal("%s: sshkey_fingerprint failed",
                                             __func__);
-                                mprintf("%s %s %s %s\n", ctx->host,
-                                    sshkey_type(l->key), fp, l->comment);
+                                mprintf("%s %s %s%s%s\n", ctx->host,
+                                    sshkey_type(l->key), fp,
+                                    l->comment[0] ? " " : "",
+                                    l->comment);
                                 if (log_level_get() >= SYSLOG_LEVEL_VERBOSE)
                                         printf("%s\n", ra);
                                 free(ra);
@@ -1650,6 +1679,9 @@ prepare_options_buf(struct sshbuf *c, int which)
             (certflags_flags & CERTOPT_USER_RC) != 0)
                 add_flag_option(c, "permit-user-rc");
         if ((which & OPTIONS_CRITICAL) != 0 &&
+            (certflags_flags & CERTOPT_NO_REQUIRE_USER_PRESENCE) != 0)
+                add_flag_option(c, "no-touch-required");
+        if ((which & OPTIONS_CRITICAL) != 0 &&
             certflags_src_addr != NULL)
                 add_string_option(c, "source-address", certflags_src_addr);
         for (i = 0; i < ncert_userext; i++) {
@@ -1676,7 +1708,8 @@ load_pkcs11_key(char *path)
                 fatal("Couldn't load CA public key \"%s\": %s",
                     path, ssh_err(r));
 
-        nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase, &keys);
+        nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase,
+            &keys, NULL);
         debug3("%s: %d keys", __func__, nkeys);
         if (nkeys <= 0)
                 fatal("cannot read public key from pkcs11");
@@ -1699,7 +1732,7 @@ load_pkcs11_key(char *path)
 static int
 agent_signer(struct sshkey *key, u_char **sigp, size_t *lenp,
     const u_char *data, size_t datalen,
-    const char *alg, u_int compat, void *ctx)
+    const char *alg, const char *provider, u_int compat, void *ctx)
 {
         int *agent_fdp = (int *)ctx;
 
@@ -1715,10 +1748,12 @@ do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
         int r, i, fd, found, agent_fd = -1;
         u_int n;
         struct sshkey *ca, *public;
-        char valid[64], *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
+        char valid[64], *otmp, *tmp, *cp, *out, *comment;
+        char *ca_fp = NULL, **plist = NULL;
         FILE *f;
         struct ssh_identitylist *agent_ids;
         size_t j;
+        struct notifier_ctx *notifier = NULL;
 
 #ifdef ENABLE_PKCS11
         pkcs11_init(1);
@@ -1759,11 +1794,16 @@ do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
         }
         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);
+        if (key_type_name != NULL) {
+                if (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);
+                }
+        } else if (ca->type == KEY_RSA) {
+                /* Default to a good signature algorithm */
+                key_type_name = "rsa-sha2-512";
         }
+        ca_fp = sshkey_fingerprint(ca, fingerprint_hash, SSH_FP_DEFAULT);
 
         for (i = 0; i < argc; i++) {
                 /* Split list of principals */
@@ -1785,9 +1825,7 @@ do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
                 if ((r = sshkey_load_public(tmp, &public, &comment)) != 0)
                         fatal("%s: unable to open \"%s\": %s",
                             __func__, tmp, ssh_err(r));
-                if (public->type != KEY_RSA && public->type != KEY_DSA &&
-                    public->type != KEY_ECDSA && public->type != KEY_ED25519 &&
-                    public->type != KEY_XMSS)
+                if (sshkey_is_cert(public))
                         fatal("%s: key \"%s\" type %s cannot be certified",
                             __func__, tmp, sshkey_type(public));
 
@@ -1811,11 +1849,21 @@ do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
 
                 if (agent_fd != -1 && (ca->flags & SSHKEY_FLAG_EXT) != 0) {
                         if ((r = sshkey_certify_custom(public, ca,
-                            key_type_name, agent_signer, &agent_fd)) != 0)
+                            key_type_name, sk_provider, agent_signer,
+                            &agent_fd)) != 0)
                                 fatal("Couldn't certify key %s via agent: %s",
                                     tmp, ssh_err(r));
                 } else {
-                        if ((sshkey_certify(public, ca, key_type_name)) != 0)
+                        if (sshkey_is_sk(ca) &&
+                            (ca->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
+                                notifier = notify_start(0,
+                                    "Confirm user presence for key %s %s",
+                                    sshkey_type(ca), ca_fp);
+                        }
+                        r = sshkey_certify(public, ca, key_type_name,
+                            sk_provider);
+                        notify_complete(notifier);
+                        if (r != 0)
                                 fatal("Couldn't certify key %s: %s",
                                     tmp, ssh_err(r));
                 }
@@ -1853,6 +1901,7 @@ do_ca_sign(struct passwd *pw, const char *ca_key_path, int prefer_agent,
                 if (cert_serial_autoinc)
                         cert_serial++;
         }
+        free(ca_fp);
 #ifdef ENABLE_PKCS11
         pkcs11_terminate();
 #endif
@@ -1951,6 +2000,10 @@ add_cert_option(char *opt)
                 certflags_flags &= ~CERTOPT_USER_RC;
         else if (strcasecmp(opt, "permit-user-rc") == 0)
                 certflags_flags |= CERTOPT_USER_RC;
+        else if (strcasecmp(opt, "touch-required") == 0)
+                certflags_flags &= ~CERTOPT_NO_REQUIRE_USER_PRESENCE;
+        else if (strcasecmp(opt, "no-touch-required") == 0)
+                certflags_flags |= CERTOPT_NO_REQUIRE_USER_PRESENCE;
         else if (strncasecmp(opt, "force-command=", 14) == 0) {
                 val = opt + 14;
                 if (*val == '\0')
@@ -2004,9 +2057,10 @@ show_options(struct sshbuf *optbuf, int in_critical)
                     strcmp(name, "permit-agent-forwarding") == 0 ||
                     strcmp(name, "permit-port-forwarding") == 0 ||
                     strcmp(name, "permit-pty") == 0 ||
-                    strcmp(name, "permit-user-rc") == 0))
+                    strcmp(name, "permit-user-rc") == 0 ||
+                    strcmp(name, "no-touch-required") == 0)) {
                         printf("\n");
-                else if (in_critical &&
+                } else if (in_critical &&
                     (strcmp(name, "force-command") == 0 ||
                     strcmp(name, "source-address") == 0)) {
                         if ((r = sshbuf_get_cstring(option, &arg, NULL)) != 0)
@@ -2135,15 +2189,10 @@ static void
 load_krl(const char *path, struct ssh_krl **krlp)
 {
         struct sshbuf *krlbuf;
-        int r, fd;
+        int r;
 
-        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)
+        if ((r = sshbuf_load_file(path, &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)
@@ -2345,7 +2394,7 @@ do_gen_krl(struct passwd *pw, int updating, const char *ca_key_path,
         struct ssh_krl *krl;
         struct stat sb;
         struct sshkey *ca = NULL;
-        int fd, i, r, wild_ca = 0;
+        int i, r, wild_ca = 0;
         char *tmp;
         struct sshbuf *kbuf;
 
@@ -2387,12 +2436,8 @@ do_gen_krl(struct passwd *pw, int updating, const char *ca_key_path,
                 fatal("sshbuf_new failed");
         if (ssh_krl_to_blob(krl, kbuf, NULL, 0) != 0)
                 fatal("Couldn't generate KRL");
-        if ((fd = open(identity_file, O_WRONLY|O_CREAT|O_TRUNC, 0644)) == -1)
-                fatal("open %s: %s", identity_file, strerror(errno));
-        if (atomicio(vwrite, fd, sshbuf_mutable_ptr(kbuf), sshbuf_len(kbuf)) !=
-            sshbuf_len(kbuf))
+        if ((r = sshbuf_write_file(identity_file, kbuf)) != 0)
                 fatal("write %s: %s", identity_file, strerror(errno));
-        close(fd);
         sshbuf_free(kbuf);
         ssh_krl_free(krl);
         sshkey_free(ca);
@@ -2488,8 +2533,7 @@ sign_one(struct sshkey *signkey, const char *filename, int fd,
 {
         struct sshbuf *sigbuf = NULL, *abuf = NULL;
         int r = SSH_ERR_INTERNAL_ERROR, wfd = -1, oerrno;
-        char *wfile = NULL;
-        char *asig = NULL;
+        char *wfile = NULL, *asig = NULL, *fp = NULL;
 
         if (!quiet) {
                 if (fd == STDIN_FILENO)
@@ -2497,7 +2541,16 @@ sign_one(struct sshkey *signkey, const char *filename, int fd,
                 else
                         fprintf(stderr, "Signing file %s\n", filename);
         }
-        if ((r = sshsig_sign_fd(signkey, NULL, fd, sig_namespace,
+        if (signer == NULL && sshkey_is_sk(signkey) &&
+            (signkey->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
+                if ((fp = sshkey_fingerprint(signkey, fingerprint_hash,
+                    SSH_FP_DEFAULT)) == NULL)
+                        fatal("%s: sshkey_fingerprint failed", __func__);
+                fprintf(stderr, "Confirm user presence for key %s %s\n",
+                    sshkey_type(signkey), fp);
+                free(fp);
+        }
+        if ((r = sshsig_sign_fd(signkey, NULL, sk_provider, fd, sig_namespace,
             &sigbuf, signer, signer_ctx)) != 0) {
                 error("Signing %s failed: %s", filename, ssh_err(r));
                 goto out;
@@ -2555,7 +2608,7 @@ sign_one(struct sshkey *signkey, const char *filename, int fd,
 }
 
 static int
-sign(const char *keypath, const char *sig_namespace, int argc, char **argv)
+sig_sign(const char *keypath, const char *sig_namespace, int argc, char **argv)
 {
         int i, fd = -1, r, ret = -1;
         int agent_fd = -1;
@@ -2626,38 +2679,37 @@ done:
 }
 
 static int
-verify(const char *signature, const char *sig_namespace, const char *principal,
-    const char *allowed_keys, const char *revoked_keys)
+sig_verify(const char *signature, const char *sig_namespace,
+    const char *principal, const char *allowed_keys, const char *revoked_keys)
 {
-        int r, ret = -1, sigfd = -1;
+        int r, ret = -1;
         struct sshbuf *sigbuf = NULL, *abuf = NULL;
         struct sshkey *sign_key = NULL;
         char *fp = NULL;
+        struct sshkey_sig_details *sig_details = NULL;
 
-        if ((abuf = sshbuf_new()) == NULL)
-                fatal("%s: sshbuf_new() failed", __func__);
-
-        if ((sigfd = open(signature, O_RDONLY)) < 0) {
-                error("Couldn't open signature file %s", signature);
-                goto done;
-        }
-
-        if ((r = sshkey_load_file(sigfd, abuf)) != 0) {
+        memset(&sig_details, 0, sizeof(sig_details));
+        if ((r = sshbuf_load_file(signature, &abuf)) != 0) {
                 error("Couldn't read signature file: %s", ssh_err(r));
                 goto done;
         }
+
         if ((r = sshsig_dearmor(abuf, &sigbuf)) != 0) {
                 error("%s: sshsig_armor: %s", __func__, ssh_err(r));
-                return r;
+                goto done;
         }
         if ((r = sshsig_verify_fd(sigbuf, STDIN_FILENO, sig_namespace,
-            &sign_key)) != 0)
+            &sign_key, &sig_details)) != 0)
                 goto done; /* sshsig_verify() prints error */
 
         if ((fp = sshkey_fingerprint(sign_key, fingerprint_hash,
             SSH_FP_DEFAULT)) == NULL)
                 fatal("%s: sshkey_fingerprint failed", __func__);
         debug("Valid (unverified) signature from key %s", fp);
+        if (sig_details != NULL) {
+                debug2("%s: signature details: counter = %u, flags = 0x%02x",
+                    __func__, sig_details->sk_counter, sig_details->sk_flags);
+        }
         free(fp);
         fp = NULL;
 
@@ -2697,21 +2749,312 @@ done:
                         printf("Could not verify signature.\n");
                 }
         }
-        if (sigfd != -1)
-                close(sigfd);
         sshbuf_free(sigbuf);
         sshbuf_free(abuf);
         sshkey_free(sign_key);
+        sshkey_sig_details_free(sig_details);
         free(fp);
         return ret;
 }
 
+static int
+sig_find_principals(const char *signature, const char *allowed_keys) {
+        int r, ret = -1;
+        struct sshbuf *sigbuf = NULL, *abuf = NULL;
+        struct sshkey *sign_key = NULL;
+        char *principals = NULL, *cp, *tmp;
+
+        if ((r = sshbuf_load_file(signature, &abuf)) != 0) {
+                error("Couldn't read signature file: %s", ssh_err(r));
+                goto done;
+        }
+        if ((r = sshsig_dearmor(abuf, &sigbuf)) != 0) {
+                error("%s: sshsig_armor: %s", __func__, ssh_err(r));
+                goto done;
+        }
+        if ((r = sshsig_get_pubkey(sigbuf, &sign_key)) != 0) {
+                error("%s: sshsig_get_pubkey: %s",
+                    __func__, ssh_err(r));
+                goto done;
+        }
+        if ((r = sshsig_find_principals(allowed_keys, sign_key,
+            &principals)) != 0) {
+                error("%s: sshsig_get_principal: %s",
+                      __func__, ssh_err(r));
+                goto done;
+        }
+        ret = 0;
+done:
+        if (ret == 0 ) {
+                /* Emit matching principals one per line */
+                tmp = principals;
+                while ((cp = strsep(&tmp, ",")) != NULL && *cp != '\0')
+                        puts(cp);
+        } else {
+                fprintf(stderr, "No principal matched.\n");
+        }
+        sshbuf_free(sigbuf);
+        sshbuf_free(abuf);
+        sshkey_free(sign_key);
+        free(principals);
+        return ret;
+}
+
+static void
+do_moduli_gen(const char *out_file, char **opts, size_t nopts)
+{
+#ifdef WITH_OPENSSL
+        /* Moduli generation/screening */
+        u_int32_t memory = 0;
+        BIGNUM *start = NULL;
+        int moduli_bits = 0;
+        FILE *out;
+        size_t i;
+        const char *errstr;
+
+        /* Parse options */
+        for (i = 0; i < nopts; i++) {
+                if (strncmp(opts[i], "memory=", 7) == 0) {
+                        memory = (u_int32_t)strtonum(opts[i]+7, 1,
+                            UINT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Memory limit is %s: %s",
+                                    errstr, opts[i]+7);
+                        }
+                } else if (strncmp(opts[i], "start=", 6) == 0) {
+                        /* XXX - also compare length against bits */
+                        if (BN_hex2bn(&start, opts[i]+6) == 0)
+                                fatal("Invalid start point.");
+                } else if (strncmp(opts[i], "bits=", 5) == 0) {
+                        moduli_bits = (int)strtonum(opts[i]+5, 1,
+                            INT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Invalid number: %s (%s)",
+                                        opts[i]+12, errstr);
+                        }
+                } else {
+                        fatal("Option \"%s\" is unsupported for moduli "
+                            "generation", opts[i]);
+                }
+        }
+
+        if ((out = fopen(out_file, "w")) == NULL) {
+                fatal("Couldn't open modulus candidate file \"%s\": %s",
+                    out_file, strerror(errno));
+        }
+        setvbuf(out, NULL, _IOLBF, 0);
+
+        if (moduli_bits == 0)
+                moduli_bits = DEFAULT_BITS;
+        if (gen_candidates(out, memory, moduli_bits, start) != 0)
+                fatal("modulus candidate generation failed");
+#else /* WITH_OPENSSL */
+        fatal("Moduli generation is not supported");
+#endif /* WITH_OPENSSL */
+}
+
+static void
+do_moduli_screen(const char *out_file, char **opts, size_t nopts)
+{
+#ifdef WITH_OPENSSL
+        /* Moduli generation/screening */
+        char *checkpoint = NULL;
+        u_int32_t generator_wanted = 0;
+        unsigned long start_lineno = 0, lines_to_process = 0;
+        int prime_tests = 0;
+        FILE *out, *in = stdin;
+        size_t i;
+        const char *errstr;
+
+        /* Parse options */
+        for (i = 0; i < nopts; i++) {
+                if (strncmp(opts[i], "lines=", 6) == 0) {
+                        lines_to_process = strtoul(opts[i]+6, NULL, 10);
+                } else if (strncmp(opts[i], "start-line=", 11) == 0) {
+                        start_lineno = strtoul(opts[i]+11, NULL, 10);
+                } else if (strncmp(opts[i], "checkpoint=", 11) == 0) {
+                        checkpoint = xstrdup(opts[i]+11);
+                } else if (strncmp(opts[i], "generator=", 10) == 0) {
+                        generator_wanted = (u_int32_t)strtonum(
+                            opts[i]+10, 1, UINT_MAX, &errstr);
+                        if (errstr != NULL) {
+                                fatal("Generator invalid: %s (%s)",
+                                    opts[i]+10, errstr);
+                        }
+                } else if (strncmp(opts[i], "prime-tests=", 12) == 0) {
+                        prime_tests = (int)strtonum(opts[i]+12, 1,
+                            INT_MAX, &errstr);
+                        if (errstr) {
+                                fatal("Invalid number: %s (%s)",
+                                        opts[i]+12, errstr);
+                        }
+                } else {
+                        fatal("Option \"%s\" is unsupported for moduli "
+                            "screening", opts[i]);
+                }
+        }
+
+        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));
+                }
+        }
+
+        if ((out = fopen(out_file, "a")) == NULL) {
+                fatal("Couldn't open moduli file \"%s\": %s",
+                    out_file, strerror(errno));
+        }
+        setvbuf(out, NULL, _IOLBF, 0);
+        if (prime_test(in, out, prime_tests == 0 ? 100 : prime_tests,
+            generator_wanted, checkpoint,
+            start_lineno, lines_to_process) != 0)
+                fatal("modulus screening failed");
+#else /* WITH_OPENSSL */
+        fatal("Moduli screening is not supported");
+#endif /* WITH_OPENSSL */
+}
+
+static char *
+private_key_passphrase(void)
+{
+        char *passphrase1, *passphrase2;
+
+        /* 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.
+                         */
+                        freezero(passphrase1, strlen(passphrase1));
+                        freezero(passphrase2, strlen(passphrase2));
+                        printf("Passphrases do not match.  Try again.\n");
+                        goto passphrase_again;
+                }
+                /* Clear the other copy of the passphrase. */
+                freezero(passphrase2, strlen(passphrase2));
+        }
+        return passphrase1;
+}
+
+static const char *
+skip_ssh_url_preamble(const char *s)
+{
+        if (strncmp(s, "ssh://", 6) == 0)
+                return s + 6;
+        else if (strncmp(s, "ssh:", 4) == 0)
+                return s + 4;
+        return s;
+}
+
+static int
+do_download_sk(const char *skprovider, const char *device)
+{
+        struct sshkey **keys;
+        size_t nkeys, i;
+        int r, ok = -1;
+        char *fp, *pin, *pass = NULL, *path, *pubpath;
+        const char *ext;
+
+        if (skprovider == NULL)
+                fatal("Cannot download keys without provider");
+
+        pin = read_passphrase("Enter PIN for authenticator: ", RP_ALLOW_STDIN);
+        if ((r = sshsk_load_resident(skprovider, device, pin,
+            &keys, &nkeys)) != 0) {
+                freezero(pin, strlen(pin));
+                error("Unable to load resident keys: %s", ssh_err(r));
+                return -1;
+        }
+        if (nkeys == 0)
+                logit("No keys to download");
+        freezero(pin, strlen(pin));
+
+        for (i = 0; i < nkeys; i++) {
+                if (keys[i]->type != KEY_ECDSA_SK &&
+                    keys[i]->type != KEY_ED25519_SK) {
+                        error("Unsupported key type %s (%d)",
+                            sshkey_type(keys[i]), keys[i]->type);
+                        continue;
+                }
+                if ((fp = sshkey_fingerprint(keys[i],
+                    fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
+                        fatal("%s: sshkey_fingerprint failed", __func__);
+                debug("%s: key %zu: %s %s %s (flags 0x%02x)", __func__, i,
+                    sshkey_type(keys[i]), fp, keys[i]->sk_application,
+                    keys[i]->sk_flags);
+                ext = skip_ssh_url_preamble(keys[i]->sk_application);
+                xasprintf(&path, "id_%s_rk%s%s",
+                    keys[i]->type == KEY_ECDSA_SK ? "ecdsa_sk" : "ed25519_sk",
+                    *ext == '\0' ? "" : "_", ext);
+
+                /* If the file already exists, ask the user to confirm. */
+                if (!confirm_overwrite(path)) {
+                        free(path);
+                        break;
+                }
+
+                /* Save the key with the application string as the comment */
+                if (pass == NULL)
+                        pass = private_key_passphrase();
+                if ((r = sshkey_save_private(keys[i], path, pass,
+                    keys[i]->sk_application, private_key_format,
+                    openssh_format_cipher, rounds)) != 0) {
+                        error("Saving key \"%s\" failed: %s",
+                            path, ssh_err(r));
+                        free(path);
+                        break;
+                }
+                if (!quiet) {
+                        printf("Saved %s key%s%s to %s\n",
+                            sshkey_type(keys[i]),
+                            *ext != '\0' ? " " : "",
+                            *ext != '\0' ? keys[i]->sk_application : "",
+                            path);
+                }
+
+                /* Save public key too */
+                xasprintf(&pubpath, "%s.pub", path);
+                free(path);
+                if ((r = sshkey_save_public(keys[i], pubpath,
+                    keys[i]->sk_application)) != 0) {
+                        free(pubpath);
+                        error("Saving public key \"%s\" failed: %s",
+                            pubpath, ssh_err(r));
+                        break;
+                }
+                free(pubpath);
+        }
+
+        if (i >= nkeys)
+                ok = 0; /* success */
+        if (pass != NULL)
+                freezero(pass, strlen(pass));
+        for (i = 0; i < nkeys; i++)
+                sshkey_free(keys[i]);
+        free(keys);
+        return ok ? 0 : -1;
+}
+
 static void
 usage(void)
 {
         fprintf(stderr,
             "usage: ssh-keygen [-q] [-b bits] [-C comment] [-f output_keyfile] [-m format]\n"
-            "                  [-N new_passphrase] [-t dsa | ecdsa | ed25519 | rsa]\n"
+            "                  [-t dsa | ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa]\n"
+            "                  [-N new_passphrase] [-O option] [-w provider]\n"
             "       ssh-keygen -p [-f keyfile] [-m format] [-N new_passphrase]\n"
             "                   [-P old_passphrase]\n"
             "       ssh-keygen -i [-f input_keyfile] [-m key_format]\n"
@@ -2727,12 +3070,12 @@ usage(void)
         fprintf(stderr,
             "       ssh-keygen -F hostname [-lv] [-f known_hosts_file]\n"
             "       ssh-keygen -H [-f known_hosts_file]\n"
+            "       ssh-keygen -K [-w provider]\n"
             "       ssh-keygen -R hostname [-f known_hosts_file]\n"
             "       ssh-keygen -r hostname [-g] [-f input_keyfile]\n"
 #ifdef WITH_OPENSSL
-            "       ssh-keygen -G output_file [-v] [-b bits] [-M memory] [-S start_point]\n"
-            "       ssh-keygen -f input_file -T output_file [-v] [-a rounds] [-J num_lines]\n"
-            "                  [-j start_line] [-K checkpt] [-W generator]\n"
+            "       ssh-keygen -M generate [-O option] output_file\n"
+            "       ssh-keygen -M screen [-f input_file] [-O option] output_file\n"
 #endif
             "       ssh-keygen -I certificate_identity -s ca_key [-hU] [-D pkcs11_provider]\n"
             "                  [-n principals] [-O option] [-V validity_interval]\n"
@@ -2742,6 +3085,7 @@ usage(void)
             "       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]\n"
             "                  file ...\n"
             "       ssh-keygen -Q -f krl_file file ...\n"
+            "       ssh-keygen -Y find-principals -s signature_file -f allowed_signers_file\n"
             "       ssh-keygen -Y check-novalidate -n namespace -s signature_file\n"
             "       ssh-keygen -Y sign -f key_file -n namespace file ...\n"
             "       ssh-keygen -Y verify -f allowed_signers_file -I signer_identity\n"
@@ -2755,32 +3099,29 @@ usage(void)
 int
 main(int argc, char **argv)
 {
-        char dotsshdir[PATH_MAX], comment[1024], *passphrase1, *passphrase2;
+        char dotsshdir[PATH_MAX], comment[1024], *passphrase;
         char *rr_hostname = NULL, *ep, *fp, *ra;
         struct sshkey *private, *public;
         struct passwd *pw;
         struct stat st;
-        int r, opt, type, fd;
+        int r, opt, type;
         int change_passphrase = 0, change_comment = 0, show_cert = 0;
         int find_host = 0, delete_host = 0, hash_hosts = 0;
         int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
         int prefer_agent = 0, convert_to = 0, convert_from = 0;
         int print_public = 0, print_generic = 0, cert_serial_autoinc = 0;
+        int do_gen_candidates = 0, do_screen_candidates = 0, download_sk = 0;
         unsigned long long cert_serial = 0;
-        char *identity_comment = NULL, *ca_key_path = NULL;
+        char *identity_comment = NULL, *ca_key_path = NULL, **opts = NULL;
+        char *sk_application = NULL, *sk_device = NULL, *sk_user = NULL;
+        char *sk_attestaion_path = NULL;
+        struct sshbuf *challenge = NULL, *attest = NULL;
+        size_t i, nopts = 0;
         u_int32_t bits = 0;
-        FILE *f;
+        uint8_t sk_flags = SSH_SK_USER_PRESENCE_REQD;
         const char *errstr;
         int log_level = SYSLOG_LEVEL_INFO;
         char *sign_op = NULL;
-#ifdef WITH_OPENSSL
-        /* Moduli generation/screening */
-        char out_file[PATH_MAX], *checkpoint = NULL;
-        u_int32_t memory = 0, generator_wanted = 0;
-        int do_gen_candidates = 0, do_screen_candidates = 0;
-        unsigned long start_lineno = 0, lines_to_process = 0;
-        BIGNUM *start = NULL;
-#endif
 
         extern int optind;
         extern char *optarg;
@@ -2803,10 +3144,12 @@ main(int argc, char **argv)
         if (gethostname(hostname, sizeof(hostname)) == -1)
                 fatal("gethostname: %s", strerror(errno));
 
-        /* Remaining characters: dw */
-        while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvxy"
-            "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Y:Z:"
-            "a:b:f:g:j:m:n:r:s:t:z:")) != -1) {
+        sk_provider = getenv("SSH_SK_PROVIDER");
+
+        /* Remaining characters: dGjJSTWx */
+        while ((opt = getopt(argc, argv, "ABHKLQUXceghiklopquvy"
+            "C:D:E:F:I:M:N:O:P:R:V:Y:Z:"
+            "a:b:f:g:m:n:r:s:t:w:z:")) != -1) {
                 switch (opt) {
                 case 'A':
                         gen_all_hostkeys = 1;
@@ -2884,6 +3227,9 @@ main(int argc, char **argv)
                 case 'g':
                         print_generic = 1;
                         break;
+                case 'K':
+                        download_sk = 1;
+                        break;
                 case 'P':
                         identity_passphrase = optarg;
                         break;
@@ -2894,7 +3240,9 @@ main(int argc, char **argv)
                         check_krl = 1;
                         break;
                 case 'O':
-                        add_cert_option(optarg);
+                        opts = xrecallocarray(opts, nopts, nopts + 1,
+                            sizeof(*opts));
+                        opts[nopts++] = xstrdup(optarg);
                         break;
                 case 'Z':
                         openssh_format_cipher = optarg;
@@ -2906,7 +3254,6 @@ main(int argc, char **argv)
                         quiet = 1;
                         break;
                 case 'e':
-                case 'x':
                         /* export key */
                         convert_to = 1;
                         break;
@@ -2964,6 +3311,9 @@ main(int argc, char **argv)
                 case 'Y':
                         sign_op = optarg;
                         break;
+                case 'w':
+                        sk_provider = optarg;
+                        break;
                 case 'z':
                         errno = 0;
                         if (*optarg == '+') {
@@ -2975,56 +3325,25 @@ main(int argc, char **argv)
                             (errno == ERANGE && cert_serial == ULLONG_MAX))
                                 fatal("Invalid serial number \"%s\"", optarg);
                         break;
-#ifdef WITH_OPENSSL
-                /* Moduli generation/screening */
-                case 'G':
-                        do_gen_candidates = 1;
-                        if (strlcpy(out_file, optarg, sizeof(out_file)) >=
-                            sizeof(out_file))
-                                fatal("Output filename too long");
-                        break;
-                case 'J':
-                        lines_to_process = strtoul(optarg, NULL, 10);
-                        break;
-                case 'j':
-                        start_lineno = strtoul(optarg, NULL, 10);
-                        break;
-                case 'K':
-                        if (strlen(optarg) >= PATH_MAX)
-                                fatal("Checkpoint filename too long");
-                        checkpoint = xstrdup(optarg);
-                        break;
                 case 'M':
-                        memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX,
-                            &errstr);
-                        if (errstr)
-                                fatal("Memory limit is %s: %s", errstr, optarg);
+                        if (strcmp(optarg, "generate") == 0)
+                                do_gen_candidates = 1;
+                        else if (strcmp(optarg, "screen") == 0)
+                                do_screen_candidates = 1;
+                        else
+                                fatal("Unsupported moduli option %s", optarg);
                         break;
-                case 'S':
-                        /* XXX - also compare length against bits */
-                        if (BN_hex2bn(&start, optarg) == 0)
-                                fatal("Invalid start point.");
-                        break;
-                case 'T':
-                        do_screen_candidates = 1;
-                        if (strlcpy(out_file, optarg, sizeof(out_file)) >=
-                            sizeof(out_file))
-                                fatal("Output filename too long");
-                        break;
-                case 'W':
-                        generator_wanted = (u_int32_t)strtonum(optarg, 1,
-                            UINT_MAX, &errstr);
-                        if (errstr != NULL)
-                                fatal("Desired generator invalid: %s (%s)",
-                                    optarg, errstr);
-                        break;
-#endif /* WITH_OPENSSL */
                 case '?':
                 default:
                         usage();
                 }
         }
 
+#ifdef ENABLE_SK_INTERNAL
+        if (sk_provider == NULL)
+                sk_provider = "internal";
+#endif
+
         /* reinit */
         log_init(argv[0], log_level, SYSLOG_FACILITY_USER, 1);
 
@@ -3032,27 +3351,47 @@ main(int argc, char **argv)
         argc -= optind;
 
         if (sign_op != NULL) {
-                if (cert_principals == NULL || *cert_principals == '\0') {
-                        error("Too few arguments for sign/verify: "
-                            "missing namespace");
-                        exit(1);
-                }
-                if (strncmp(sign_op, "sign", 4) == 0) {
+                if (strncmp(sign_op, "find-principals", 15) == 0) {
+                        if (ca_key_path == NULL) {
+                                error("Too few arguments for find-principals:"
+                                      "missing signature file");
+                                exit(1);
+                        }
+                        if (!have_identity) {
+                                error("Too few arguments for find-principals:"
+                                      "missing allowed keys file");
+                                exit(1);
+                        }
+                        return sig_find_principals(ca_key_path, identity_file);
+                } else if (strncmp(sign_op, "sign", 4) == 0) {
+                        if (cert_principals == NULL ||
+                            *cert_principals == '\0') {
+                                error("Too few arguments for sign: "
+                                    "missing namespace");
+                                exit(1);
+                        }
                         if (!have_identity) {
                                 error("Too few arguments for sign: "
                                     "missing key");
                                 exit(1);
                         }
-                        return sign(identity_file, cert_principals, argc, argv);
+                        return sig_sign(identity_file, cert_principals,
+                            argc, argv);
                 } else if (strncmp(sign_op, "check-novalidate", 16) == 0) {
                         if (ca_key_path == NULL) {
                                 error("Too few arguments for check-novalidate: "
                                       "missing signature file");
                                 exit(1);
                         }
-                        return verify(ca_key_path, cert_principals,
-                                      NULL, NULL, NULL);
+                        return sig_verify(ca_key_path, cert_principals,
+                            NULL, NULL, NULL);
                 } else if (strncmp(sign_op, "verify", 6) == 0) {
+                        if (cert_principals == NULL ||
+                            *cert_principals == '\0') {
+                                error("Too few arguments for verify: "
+                                    "missing namespace");
+                                exit(1);
+                        }
                         if (ca_key_path == NULL) {
                                 error("Too few arguments for verify: "
                                     "missing signature file");
@@ -3068,9 +3407,10 @@ main(int argc, char **argv)
                                     "missing principal ID");
                                 exit(1);
                         }
-                        return verify(ca_key_path, cert_principals,
+                        return sig_verify(ca_key_path, cert_principals,
                             cert_key_id, identity_file, rr_hostname);
                 }
+                error("Unsupported operation for -Y: \"%s\"", sign_op);
                 usage();
                 /* NOTREACHED */
         }
@@ -3080,7 +3420,8 @@ main(int argc, char **argv)
                         error("Too few arguments.");
                         usage();
                 }
-        } else if (argc > 0 && !gen_krl && !check_krl) {
+        } else if (argc > 0 && !gen_krl && !check_krl &&
+            !do_gen_candidates && !do_screen_candidates) {
                 error("Too many arguments.");
                 usage();
         }
@@ -3104,6 +3445,8 @@ main(int argc, char **argv)
         if (ca_key_path != NULL) {
                 if (cert_key_id == NULL)
                         fatal("Must specify key id (-I) when certifying");
+                for (i = 0; i < nopts; i++)
+                        add_cert_option(opts[i]);
                 do_ca_sign(pw, ca_key_path, prefer_agent,
                     cert_serial, cert_serial_autoinc, argc, argv);
         }
@@ -3115,6 +3458,17 @@ main(int argc, char **argv)
         }
         if (pkcs11provider != NULL)
                 do_download(pw);
+        if (download_sk) {
+                for (i = 0; i < nopts; i++) {
+                        if (strncasecmp(opts[i], "device=", 7) == 0) {
+                                sk_device = xstrdup(opts[i] + 7);
+                        } else {
+                                fatal("Option \"%s\" is unsupported for "
+                                    "FIDO authenticator download", opts[i]);
+                        }
+                }
+                return do_download_sk(sk_provider, sk_device);
+        }
         if (print_fingerprint || print_bubblebabble)
                 do_fingerprint(pw);
         if (change_passphrase)
@@ -3164,47 +3518,20 @@ main(int argc, char **argv)
                 }
         }
 
-#ifdef WITH_OPENSSL
+        if (do_gen_candidates || do_screen_candidates) {
+                if (argc <= 0)
+                        fatal("No output file specified");
+                else if (argc > 1)
+                        fatal("Too many output files specified");
+        }
         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);
+                do_moduli_gen(argv[0], opts, nopts);
+                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);
+                do_moduli_screen(argv[0], opts, nopts);
+                return 0;
         }
-#endif
 
         if (gen_all_hostkeys) {
                 do_gen_all_hostkeys(pw);
@@ -3220,8 +3547,78 @@ main(int argc, char **argv)
         if (!quiet)
                 printf("Generating public/private %s key pair.\n",
                     key_type_name);
-        if ((r = sshkey_generate(type, bits, &private)) != 0)
-                fatal("sshkey_generate failed");
+        switch (type) {
+        case KEY_ECDSA_SK:
+        case KEY_ED25519_SK:
+                for (i = 0; i < nopts; i++) {
+                        if (strcasecmp(opts[i], "no-touch-required") == 0) {
+                                sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
+                        } else if (strcasecmp(opts[i], "resident") == 0) {
+                                sk_flags |= SSH_SK_RESIDENT_KEY;
+                        } else if (strncasecmp(opts[i], "device=", 7) == 0) {
+                                sk_device = xstrdup(opts[i] + 7);
+                        } else if (strncasecmp(opts[i], "user=", 5) == 0) {
+                                sk_user = xstrdup(opts[i] + 5);
+                        } else if (strncasecmp(opts[i], "challenge=", 10) == 0) {
+                                if ((r = sshbuf_load_file(opts[i] + 10,
+                                    &challenge)) != 0) {
+                                        fatal("Unable to load FIDO enrollment "
+                                            "challenge \"%s\": %s",
+                                            opts[i] + 10, ssh_err(r));
+                                }
+                        } else if (strncasecmp(opts[i],
+                            "write-attestation=", 18) == 0) {
+                                sk_attestaion_path = opts[i] + 18;
+                        } else if (strncasecmp(opts[i],
+                            "application=", 12) == 0) {
+                                sk_application = xstrdup(opts[i] + 12);
+                                if (strncmp(sk_application, "ssh:", 4) != 0) {
+                                        fatal("FIDO application string must "
+                                            "begin with \"ssh:\"");
+                                }
+                        } else {
+                                fatal("Option \"%s\" is unsupported for "
+                                    "FIDO authenticator enrollment", opts[i]);
+                        }
+                }
+                if (!quiet) {
+                        printf("You may need to touch your authenticator "
+                            "to authorize key generation.\n");
+                }
+                passphrase = NULL;
+                if ((attest = sshbuf_new()) == NULL)
+                        fatal("sshbuf_new failed");
+                for (i = 0 ; ; i++) {
+                        fflush(stdout);
+                        r = sshsk_enroll(type, sk_provider, sk_device,
+                            sk_application == NULL ? "ssh:" : sk_application,
+                            sk_user, sk_flags, passphrase, challenge,
+                            &private, attest);
+                        if (r == 0)
+                                break;
+                        if (r != SSH_ERR_KEY_WRONG_PASSPHRASE)
+                                fatal("Key enrollment failed: %s", ssh_err(r));
+                        else if (i > 0)
+                                error("PIN incorrect");
+                        if (passphrase != NULL) {
+                                freezero(passphrase, strlen(passphrase));
+                                passphrase = NULL;
+                        }
+                        if (i >= 3)
+                                fatal("Too many incorrect PINs");
+                        passphrase = read_passphrase("Enter PIN for "
+                            "authenticator: ", RP_ALLOW_STDIN);
+                }
+                if (passphrase != NULL) {
+                        freezero(passphrase, strlen(passphrase));
+                        passphrase = NULL;
+                }
+                break;
+        default:
+                if ((r = sshkey_generate(type, bits, &private)) != 0)
+                        fatal("sshkey_generate failed");
+                break;
+        }
         if ((r = sshkey_from_private(private, &public)) != 0)
                 fatal("sshkey_from_private failed: %s\n", ssh_err(r));
 
@@ -3246,35 +3643,9 @@ main(int argc, char **argv)
         /* If the file already exists, ask the user to confirm. */
         if (!confirm_overwrite(identity_file))
                 exit(1);
-        /* Ask for a passphrase (twice). */
-        if (identity_passphrase)
-                passphrase1 = xstrdup(identity_passphrase);
-        else if (identity_new_passphrase)
-                passphrase1 = xstrdup(identity_new_passphrase);
-        else {
-passphrase_again:
-                passphrase1 =
-                        read_passphrase("Enter passphrase (empty for no "
-                            "passphrase): ", RP_ALLOW_STDIN);
-                passphrase2 = read_passphrase("Enter same passphrase again: ",
-                    RP_ALLOW_STDIN);
-                if (strcmp(passphrase1, passphrase2) != 0) {
-                        /*
-                         * The passphrases do not match.  Clear them and
-                         * retry.
-                         */
-                        explicit_bzero(passphrase1, strlen(passphrase1));
-                        explicit_bzero(passphrase2, strlen(passphrase2));
-                        free(passphrase1);
-                        free(passphrase2);
-                        printf("Passphrases do not match.  Try again.\n");
-                        goto passphrase_again;
-                }
-                /* Clear the other copy of the passphrase. */
-                explicit_bzero(passphrase2, strlen(passphrase2));
-                free(passphrase2);
-        }
 
+        /* Determine the passphrase for the private key */
+        passphrase = private_key_passphrase();
         if (identity_comment) {
                 strlcpy(comment, identity_comment, sizeof(comment));
         } else {
@@ -3283,35 +3654,26 @@ passphrase_again:
         }
 
         /* Save the key with the given passphrase and comment. */
-        if ((r = sshkey_save_private(private, identity_file, passphrase1,
+        if ((r = sshkey_save_private(private, identity_file, passphrase,
             comment, private_key_format, openssh_format_cipher, rounds)) != 0) {
                 error("Saving key \"%s\" failed: %s",
                     identity_file, ssh_err(r));
-                explicit_bzero(passphrase1, strlen(passphrase1));
-                free(passphrase1);
+                freezero(passphrase, strlen(passphrase));
                 exit(1);
         }
-        /* Clear the passphrase. */
-        explicit_bzero(passphrase1, strlen(passphrase1));
-        free(passphrase1);
-
-        /* Clear the private key and the random number generator. */
+        freezero(passphrase, strlen(passphrase));
         sshkey_free(private);
 
-        if (!quiet)
-                printf("Your identification has been saved in %s.\n", identity_file);
+        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)
+        if ((r = sshkey_save_public(public, identity_file, comment)) != 0) {
                 fatal("Unable to save public key to %s: %s",
                     identity_file, strerror(errno));
-        if ((f = fdopen(fd, "w")) == NULL)
-                fatal("fdopen %s failed: %s", identity_file, strerror(errno));
-        if ((r = sshkey_write(public, f)) != 0)
-                error("write key failed: %s", ssh_err(r));
-        fprintf(f, " %s\n", comment);
-        if (ferror(f) || fclose(f) != 0)
-                fatal("write public failed: %s", strerror(errno));
+        }
 
         if (!quiet) {
                 fp = sshkey_fingerprint(public, fingerprint_hash,
@@ -3320,7 +3682,7 @@ passphrase_again:
                     SSH_FP_RANDOMART);
                 if (fp == NULL || ra == NULL)
                         fatal("sshkey_fingerprint failed");
-                printf("Your public key has been saved in %s.\n",
+                printf("Your public key has been saved in %s\n",
                     identity_file);
                 printf("The key fingerprint is:\n");
                 printf("%s %s\n", fp, comment);
@@ -3330,6 +3692,22 @@ passphrase_again:
                 free(fp);
         }
 
+        if (sk_attestaion_path != NULL) {
+                if (attest == NULL || sshbuf_len(attest) == 0) {
+                        fatal("Enrollment did not return attestation "
+                            "certificate");
+                }
+                if ((r = sshbuf_write_file(sk_attestaion_path, attest)) != 0) {
+                        fatal("Unable to write attestation certificate "
+                            "\"%s\": %s", sk_attestaion_path, ssh_err(r));
+                }
+                if (!quiet) {
+                        printf("Your FIDO attestation certificate has been "
+                            "saved in %s\n", sk_attestaion_path);
+                }
+        }
+        sshbuf_free(attest);
         sshkey_free(public);
+
         exit(0);
 }