Adding upstream version 1:9.6p1.upstream/1%9.6p1

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

1 files changed, 3706 insertions, 0 deletions

diff --git a/sshkey.c b/sshkey.c
new file mode 100644
index 0000000..06db9b5
--- /dev/null
+++ b/sshkey.c
@@ -0,0 +1,3706 @@
+/* $OpenBSD: sshkey.c,v 1.140 2023/10/16 08:40:00 dtucker Exp $ */
+/*
+ * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
+ * Copyright (c) 2008 Alexander von Gernler.  All rights reserved.
+ * Copyright (c) 2010,2011 Damien Miller.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <netinet/in.h>
+
+#ifdef WITH_OPENSSL
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/pem.h>
+#endif
+
+#include "crypto_api.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <resolv.h>
+#include <time.h>
+#ifdef HAVE_UTIL_H
+#include <util.h>
+#endif /* HAVE_UTIL_H */
+
+#include "ssh2.h"
+#include "ssherr.h"
+#include "misc.h"
+#include "sshbuf.h"
+#include "cipher.h"
+#include "digest.h"
+#define SSHKEY_INTERNAL
+#include "sshkey.h"
+#include "match.h"
+#include "ssh-sk.h"
+
+#ifdef WITH_XMSS
+#include "sshkey-xmss.h"
+#include "xmss_fast.h"
+#endif
+
+#include "openbsd-compat/openssl-compat.h"
+
+/* openssh private key file format */
+#define MARK_BEGIN		"-----BEGIN OPENSSH PRIVATE KEY-----\n"
+#define MARK_END		"-----END OPENSSH PRIVATE KEY-----\n"
+#define MARK_BEGIN_LEN		(sizeof(MARK_BEGIN) - 1)
+#define MARK_END_LEN		(sizeof(MARK_END) - 1)
+#define KDFNAME			"bcrypt"
+#define AUTH_MAGIC		"openssh-key-v1"
+#define SALT_LEN		16
+#define DEFAULT_CIPHERNAME	"aes256-ctr"
+#define	DEFAULT_ROUNDS		24
+
+/* Version identification string for SSH v1 identity files. */
+#define LEGACY_BEGIN		"SSH PRIVATE KEY FILE FORMAT 1.1\n"
+
+/*
+ * Constants relating to "shielding" support; protection of keys expected
+ * to remain in memory for long durations
+ */
+#define SSHKEY_SHIELD_PREKEY_LEN	(16 * 1024)
+#define SSHKEY_SHIELD_CIPHER		"aes256-ctr" /* XXX want AES-EME* */
+#define SSHKEY_SHIELD_PREKEY_HASH	SSH_DIGEST_SHA512
+
+int	sshkey_private_serialize_opt(struct sshkey *key,
+    struct sshbuf *buf, enum sshkey_serialize_rep);
+static int sshkey_from_blob_internal(struct sshbuf *buf,
+    struct sshkey **keyp, int allow_cert);
+
+/* Supported key types */
+extern const struct sshkey_impl sshkey_ed25519_impl;
+extern const struct sshkey_impl sshkey_ed25519_cert_impl;
+extern const struct sshkey_impl sshkey_ed25519_sk_impl;
+extern const struct sshkey_impl sshkey_ed25519_sk_cert_impl;
+#ifdef WITH_OPENSSL
+# ifdef OPENSSL_HAS_ECC
+#  ifdef ENABLE_SK
+extern const struct sshkey_impl sshkey_ecdsa_sk_impl;
+extern const struct sshkey_impl sshkey_ecdsa_sk_cert_impl;
+extern const struct sshkey_impl sshkey_ecdsa_sk_webauthn_impl;
+#  endif /* ENABLE_SK */
+extern const struct sshkey_impl sshkey_ecdsa_nistp256_impl;
+extern const struct sshkey_impl sshkey_ecdsa_nistp256_cert_impl;
+extern const struct sshkey_impl sshkey_ecdsa_nistp384_impl;
+extern const struct sshkey_impl sshkey_ecdsa_nistp384_cert_impl;
+#  ifdef OPENSSL_HAS_NISTP521
+extern const struct sshkey_impl sshkey_ecdsa_nistp521_impl;
+extern const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl;
+#  endif /* OPENSSL_HAS_NISTP521 */
+# endif /* OPENSSL_HAS_ECC */
+extern const struct sshkey_impl sshkey_rsa_impl;
+extern const struct sshkey_impl sshkey_rsa_cert_impl;
+extern const struct sshkey_impl sshkey_rsa_sha256_impl;
+extern const struct sshkey_impl sshkey_rsa_sha256_cert_impl;
+extern const struct sshkey_impl sshkey_rsa_sha512_impl;
+extern const struct sshkey_impl sshkey_rsa_sha512_cert_impl;
+extern const struct sshkey_impl sshkey_dss_impl;
+extern const struct sshkey_impl sshkey_dsa_cert_impl;
+#endif /* WITH_OPENSSL */
+#ifdef WITH_XMSS
+extern const struct sshkey_impl sshkey_xmss_impl;
+extern const struct sshkey_impl sshkey_xmss_cert_impl;
+#endif
+
+const struct sshkey_impl * const keyimpls[] = {
+	&sshkey_ed25519_impl,
+	&sshkey_ed25519_cert_impl,
+#ifdef ENABLE_SK
+	&sshkey_ed25519_sk_impl,
+	&sshkey_ed25519_sk_cert_impl,
+#endif
+#ifdef WITH_OPENSSL
+# ifdef OPENSSL_HAS_ECC
+	&sshkey_ecdsa_nistp256_impl,
+	&sshkey_ecdsa_nistp256_cert_impl,
+	&sshkey_ecdsa_nistp384_impl,
+	&sshkey_ecdsa_nistp384_cert_impl,
+#  ifdef OPENSSL_HAS_NISTP521
+	&sshkey_ecdsa_nistp521_impl,
+	&sshkey_ecdsa_nistp521_cert_impl,
+#  endif /* OPENSSL_HAS_NISTP521 */
+#  ifdef ENABLE_SK
+	&sshkey_ecdsa_sk_impl,
+	&sshkey_ecdsa_sk_cert_impl,
+	&sshkey_ecdsa_sk_webauthn_impl,
+#  endif /* ENABLE_SK */
+# endif /* OPENSSL_HAS_ECC */
+	&sshkey_dss_impl,
+	&sshkey_dsa_cert_impl,
+	&sshkey_rsa_impl,
+	&sshkey_rsa_cert_impl,
+	&sshkey_rsa_sha256_impl,
+	&sshkey_rsa_sha256_cert_impl,
+	&sshkey_rsa_sha512_impl,
+	&sshkey_rsa_sha512_cert_impl,
+#endif /* WITH_OPENSSL */
+#ifdef WITH_XMSS
+	&sshkey_xmss_impl,
+	&sshkey_xmss_cert_impl,
+#endif
+	NULL
+};
+
+static const struct sshkey_impl *
+sshkey_impl_from_type(int type)
+{
+	int i;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		if (keyimpls[i]->type == type)
+			return keyimpls[i];
+	}
+	return NULL;
+}
+
+static const struct sshkey_impl *
+sshkey_impl_from_type_nid(int type, int nid)
+{
+	int i;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		if (keyimpls[i]->type == type &&
+		    (keyimpls[i]->nid == 0 || keyimpls[i]->nid == nid))
+			return keyimpls[i];
+	}
+	return NULL;
+}
+
+static const struct sshkey_impl *
+sshkey_impl_from_key(const struct sshkey *k)
+{
+	if (k == NULL)
+		return NULL;
+	return sshkey_impl_from_type_nid(k->type, k->ecdsa_nid);
+}
+
+const char *
+sshkey_type(const struct sshkey *k)
+{
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
+		return "unknown";
+	return impl->shortname;
+}
+
+static const char *
+sshkey_ssh_name_from_type_nid(int type, int nid)
+{
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_type_nid(type, nid)) == NULL)
+		return "ssh-unknown";
+	return impl->name;
+}
+
+int
+sshkey_type_is_cert(int type)
+{
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_type(type)) == NULL)
+		return 0;
+	return impl->cert;
+}
+
+const char *
+sshkey_ssh_name(const struct sshkey *k)
+{
+	return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid);
+}
+
+const char *
+sshkey_ssh_name_plain(const struct sshkey *k)
+{
+	return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type),
+	    k->ecdsa_nid);
+}
+
+int
+sshkey_type_from_name(const char *name)
+{
+	int i;
+	const struct sshkey_impl *impl;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		impl = keyimpls[i];
+		/* Only allow shortname matches for plain key types */
+		if ((impl->name != NULL && strcmp(name, impl->name) == 0) ||
+		    (!impl->cert && strcasecmp(impl->shortname, name) == 0))
+			return impl->type;
+	}
+	return KEY_UNSPEC;
+}
+
+static int
+key_type_is_ecdsa_variant(int type)
+{
+	switch (type) {
+	case KEY_ECDSA:
+	case KEY_ECDSA_CERT:
+	case KEY_ECDSA_SK:
+	case KEY_ECDSA_SK_CERT:
+		return 1;
+	}
+	return 0;
+}
+
+int
+sshkey_ecdsa_nid_from_name(const char *name)
+{
+	int i;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		if (!key_type_is_ecdsa_variant(keyimpls[i]->type))
+			continue;
+		if (keyimpls[i]->name != NULL &&
+		    strcmp(name, keyimpls[i]->name) == 0)
+			return keyimpls[i]->nid;
+	}
+	return -1;
+}
+
+int
+sshkey_match_keyname_to_sigalgs(const char *keyname, const char *sigalgs)
+{
+	int ktype;
+
+	if (sigalgs == NULL || *sigalgs == '\0' ||
+	    (ktype = sshkey_type_from_name(keyname)) == KEY_UNSPEC)
+		return 0;
+	else if (ktype == KEY_RSA) {
+		return match_pattern_list("ssh-rsa", sigalgs, 0) == 1 ||
+		    match_pattern_list("rsa-sha2-256", sigalgs, 0) == 1 ||
+		    match_pattern_list("rsa-sha2-512", sigalgs, 0) == 1;
+	} else if (ktype == KEY_RSA_CERT) {
+		return match_pattern_list("ssh-rsa-cert-v01@openssh.com",
+		    sigalgs, 0) == 1 ||
+		    match_pattern_list("rsa-sha2-256-cert-v01@openssh.com",
+		    sigalgs, 0) == 1 ||
+		    match_pattern_list("rsa-sha2-512-cert-v01@openssh.com",
+		    sigalgs, 0) == 1;
+	} else
+		return match_pattern_list(keyname, sigalgs, 0) == 1;
+}
+
+char *
+sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep)
+{
+	char *tmp, *ret = NULL;
+	size_t i, nlen, rlen = 0;
+	const struct sshkey_impl *impl;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		impl = keyimpls[i];
+		if (impl->name == NULL)
+			continue;
+		if (!include_sigonly && impl->sigonly)
+			continue;
+		if ((certs_only && !impl->cert) || (plain_only && impl->cert))
+			continue;
+		if (ret != NULL)
+			ret[rlen++] = sep;
+		nlen = strlen(impl->name);
+		if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
+			free(ret);
+			return NULL;
+		}
+		ret = tmp;
+		memcpy(ret + rlen, impl->name, nlen + 1);
+		rlen += nlen;
+	}
+	return ret;
+}
+
+int
+sshkey_names_valid2(const char *names, int allow_wildcard, int plain_only)
+{
+	char *s, *cp, *p;
+	const struct sshkey_impl *impl;
+	int i, type;
+
+	if (names == NULL || strcmp(names, "") == 0)
+		return 0;
+	if ((s = cp = strdup(names)) == NULL)
+		return 0;
+	for ((p = strsep(&cp, ",")); p && *p != '\0';
+	    (p = strsep(&cp, ","))) {
+		type = sshkey_type_from_name(p);
+		if (type == KEY_UNSPEC) {
+			if (allow_wildcard) {
+				/*
+				 * Try matching key types against the string.
+				 * If any has a positive or negative match then
+				 * the component is accepted.
+				 */
+				impl = NULL;
+				for (i = 0; keyimpls[i] != NULL; i++) {
+					if (match_pattern_list(
+					    keyimpls[i]->name, p, 0) != 0) {
+						impl = keyimpls[i];
+						break;
+					}
+				}
+				if (impl != NULL)
+					continue;
+			}
+			free(s);
+			return 0;
+		} else if (plain_only && sshkey_type_is_cert(type)) {
+			free(s);
+			return 0;
+		}
+	}
+	free(s);
+	return 1;
+}
+
+u_int
+sshkey_size(const struct sshkey *k)
+{
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
+		return 0;
+	if (impl->funcs->size != NULL)
+		return impl->funcs->size(k);
+	return impl->keybits;
+}
+
+static int
+sshkey_type_is_valid_ca(int type)
+{
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_type(type)) == NULL)
+		return 0;
+	/* All non-certificate types may act as CAs */
+	return !impl->cert;
+}
+
+int
+sshkey_is_cert(const struct sshkey *k)
+{
+	if (k == NULL)
+		return 0;
+	return sshkey_type_is_cert(k->type);
+}
+
+int
+sshkey_is_sk(const struct sshkey *k)
+{
+	if (k == NULL)
+		return 0;
+	switch (sshkey_type_plain(k->type)) {
+	case KEY_ECDSA_SK:
+	case KEY_ED25519_SK:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+/* Return the cert-less equivalent to a certified key type */
+int
+sshkey_type_plain(int type)
+{
+	switch (type) {
+	case KEY_RSA_CERT:
+		return KEY_RSA;
+	case KEY_DSA_CERT:
+		return KEY_DSA;
+	case KEY_ECDSA_CERT:
+		return KEY_ECDSA;
+	case KEY_ECDSA_SK_CERT:
+		return KEY_ECDSA_SK;
+	case KEY_ED25519_CERT:
+		return KEY_ED25519;
+	case KEY_ED25519_SK_CERT:
+		return KEY_ED25519_SK;
+	case KEY_XMSS_CERT:
+		return KEY_XMSS;
+	default:
+		return type;
+	}
+}
+
+/* Return the cert equivalent to a plain key type */
+static int
+sshkey_type_certified(int type)
+{
+	switch (type) {
+	case KEY_RSA:
+		return KEY_RSA_CERT;
+	case KEY_DSA:
+		return KEY_DSA_CERT;
+	case KEY_ECDSA:
+		return KEY_ECDSA_CERT;
+	case KEY_ECDSA_SK:
+		return KEY_ECDSA_SK_CERT;
+	case KEY_ED25519:
+		return KEY_ED25519_CERT;
+	case KEY_ED25519_SK:
+		return KEY_ED25519_SK_CERT;
+	case KEY_XMSS:
+		return KEY_XMSS_CERT;
+	default:
+		return -1;
+	}
+}
+
+#ifdef WITH_OPENSSL
+/* XXX: these are really begging for a table-driven approach */
+int
+sshkey_curve_name_to_nid(const char *name)
+{
+	if (strcmp(name, "nistp256") == 0)
+		return NID_X9_62_prime256v1;
+	else if (strcmp(name, "nistp384") == 0)
+		return NID_secp384r1;
+# ifdef OPENSSL_HAS_NISTP521
+	else if (strcmp(name, "nistp521") == 0)
+		return NID_secp521r1;
+# endif /* OPENSSL_HAS_NISTP521 */
+	else
+		return -1;
+}
+
+u_int
+sshkey_curve_nid_to_bits(int nid)
+{
+	switch (nid) {
+	case NID_X9_62_prime256v1:
+		return 256;
+	case NID_secp384r1:
+		return 384;
+# ifdef OPENSSL_HAS_NISTP521
+	case NID_secp521r1:
+		return 521;
+# endif /* OPENSSL_HAS_NISTP521 */
+	default:
+		return 0;
+	}
+}
+
+int
+sshkey_ecdsa_bits_to_nid(int bits)
+{
+	switch (bits) {
+	case 256:
+		return NID_X9_62_prime256v1;
+	case 384:
+		return NID_secp384r1;
+# ifdef OPENSSL_HAS_NISTP521
+	case 521:
+		return NID_secp521r1;
+# endif /* OPENSSL_HAS_NISTP521 */
+	default:
+		return -1;
+	}
+}
+
+const char *
+sshkey_curve_nid_to_name(int nid)
+{
+	switch (nid) {
+	case NID_X9_62_prime256v1:
+		return "nistp256";
+	case NID_secp384r1:
+		return "nistp384";
+# ifdef OPENSSL_HAS_NISTP521
+	case NID_secp521r1:
+		return "nistp521";
+# endif /* OPENSSL_HAS_NISTP521 */
+	default:
+		return NULL;
+	}
+}
+
+int
+sshkey_ec_nid_to_hash_alg(int nid)
+{
+	int kbits = sshkey_curve_nid_to_bits(nid);
+
+	if (kbits <= 0)
+		return -1;
+
+	/* RFC5656 section 6.2.1 */
+	if (kbits <= 256)
+		return SSH_DIGEST_SHA256;
+	else if (kbits <= 384)
+		return SSH_DIGEST_SHA384;
+	else
+		return SSH_DIGEST_SHA512;
+}
+#endif /* WITH_OPENSSL */
+
+static void
+cert_free(struct sshkey_cert *cert)
+{
+	u_int i;
+
+	if (cert == NULL)
+		return;
+	sshbuf_free(cert->certblob);
+	sshbuf_free(cert->critical);
+	sshbuf_free(cert->extensions);
+	free(cert->key_id);
+	for (i = 0; i < cert->nprincipals; i++)
+		free(cert->principals[i]);
+	free(cert->principals);
+	sshkey_free(cert->signature_key);
+	free(cert->signature_type);
+	freezero(cert, sizeof(*cert));
+}
+
+static struct sshkey_cert *
+cert_new(void)
+{
+	struct sshkey_cert *cert;
+
+	if ((cert = calloc(1, sizeof(*cert))) == NULL)
+		return NULL;
+	if ((cert->certblob = sshbuf_new()) == NULL ||
+	    (cert->critical = sshbuf_new()) == NULL ||
+	    (cert->extensions = sshbuf_new()) == NULL) {
+		cert_free(cert);
+		return NULL;
+	}
+	cert->key_id = NULL;
+	cert->principals = NULL;
+	cert->signature_key = NULL;
+	cert->signature_type = NULL;
+	return cert;
+}
+
+struct sshkey *
+sshkey_new(int type)
+{
+	struct sshkey *k;
+	const struct sshkey_impl *impl = NULL;
+
+	if (type != KEY_UNSPEC &&
+	    (impl = sshkey_impl_from_type(type)) == NULL)
+		return NULL;
+
+	/* All non-certificate types may act as CAs */
+	if ((k = calloc(1, sizeof(*k))) == NULL)
+		return NULL;
+	k->type = type;
+	k->ecdsa_nid = -1;
+	if (impl != NULL && impl->funcs->alloc != NULL) {
+		if (impl->funcs->alloc(k) != 0) {
+			free(k);
+			return NULL;
+		}
+	}
+	if (sshkey_is_cert(k)) {
+		if ((k->cert = cert_new()) == NULL) {
+			sshkey_free(k);
+			return NULL;
+		}
+	}
+
+	return k;
+}
+
+/* Frees common FIDO fields */
+void
+sshkey_sk_cleanup(struct sshkey *k)
+{
+	free(k->sk_application);
+	sshbuf_free(k->sk_key_handle);
+	sshbuf_free(k->sk_reserved);
+	k->sk_application = NULL;
+	k->sk_key_handle = k->sk_reserved = NULL;
+}
+
+static void
+sshkey_free_contents(struct sshkey *k)
+{
+	const struct sshkey_impl *impl;
+
+	if (k == NULL)
+		return;
+	if ((impl = sshkey_impl_from_type(k->type)) != NULL &&
+	    impl->funcs->cleanup != NULL)
+		impl->funcs->cleanup(k);
+	if (sshkey_is_cert(k))
+		cert_free(k->cert);
+	freezero(k->shielded_private, k->shielded_len);
+	freezero(k->shield_prekey, k->shield_prekey_len);
+}
+
+void
+sshkey_free(struct sshkey *k)
+{
+	sshkey_free_contents(k);
+	freezero(k, sizeof(*k));
+}
+
+static int
+cert_compare(struct sshkey_cert *a, struct sshkey_cert *b)
+{
+	if (a == NULL && b == NULL)
+		return 1;
+	if (a == NULL || b == NULL)
+		return 0;
+	if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob))
+		return 0;
+	if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob),
+	    sshbuf_len(a->certblob)) != 0)
+		return 0;
+	return 1;
+}
+
+/* Compares FIDO-specific pubkey fields only */
+int
+sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b)
+{
+	if (a->sk_application == NULL || b->sk_application == NULL)
+		return 0;
+	if (strcmp(a->sk_application, b->sk_application) != 0)
+		return 0;
+	return 1;
+}
+
+/*
+ * Compare public portions of key only, allowing comparisons between
+ * certificates and plain keys too.
+ */
+int
+sshkey_equal_public(const struct sshkey *a, const struct sshkey *b)
+{
+	const struct sshkey_impl *impl;
+
+	if (a == NULL || b == NULL ||
+	    sshkey_type_plain(a->type) != sshkey_type_plain(b->type))
+		return 0;
+	if ((impl = sshkey_impl_from_type(a->type)) == NULL)
+		return 0;
+	return impl->funcs->equal(a, b);
+}
+
+int
+sshkey_equal(const struct sshkey *a, const struct sshkey *b)
+{
+	if (a == NULL || b == NULL || a->type != b->type)
+		return 0;
+	if (sshkey_is_cert(a)) {
+		if (!cert_compare(a->cert, b->cert))
+			return 0;
+	}
+	return sshkey_equal_public(a, b);
+}
+
+
+/* Serialise common FIDO key parts */
+int
+sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b)
+{
+	int r;
+
+	if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0)
+		return r;
+
+	return 0;
+}
+
+static int
+to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain,
+  enum sshkey_serialize_rep opts)
+{
+	int type, ret = SSH_ERR_INTERNAL_ERROR;
+	const char *typename;
+	const struct sshkey_impl *impl;
+
+	if (key == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	type = force_plain ? sshkey_type_plain(key->type) : key->type;
+
+	if (sshkey_type_is_cert(type)) {
+		if (key->cert == NULL)
+			return SSH_ERR_EXPECTED_CERT;
+		if (sshbuf_len(key->cert->certblob) == 0)
+			return SSH_ERR_KEY_LACKS_CERTBLOB;
+		/* Use the existing blob */
+		if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0)
+			return ret;
+		return 0;
+	}
+	if ((impl = sshkey_impl_from_type(type)) == NULL)
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+
+	typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid);
+	if ((ret = sshbuf_put_cstring(b, typename)) != 0)
+		return ret;
+	return impl->funcs->serialize_public(key, b, opts);
+}
+
+int
+sshkey_putb(const struct sshkey *key, struct sshbuf *b)
+{
+	return to_blob_buf(key, b, 0, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+int
+sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b,
+    enum sshkey_serialize_rep opts)
+{
+	struct sshbuf *tmp;
+	int r;
+
+	if ((tmp = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	r = to_blob_buf(key, tmp, 0, opts);
+	if (r == 0)
+		r = sshbuf_put_stringb(b, tmp);
+	sshbuf_free(tmp);
+	return r;
+}
+
+int
+sshkey_puts(const struct sshkey *key, struct sshbuf *b)
+{
+	return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+int
+sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b)
+{
+	return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+static int
+to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain,
+    enum sshkey_serialize_rep opts)
+{
+	int ret = SSH_ERR_INTERNAL_ERROR;
+	size_t len;
+	struct sshbuf *b = NULL;
+
+	if (lenp != NULL)
+		*lenp = 0;
+	if (blobp != NULL)
+		*blobp = NULL;
+	if ((b = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0)
+		goto out;
+	len = sshbuf_len(b);
+	if (lenp != NULL)
+		*lenp = len;
+	if (blobp != NULL) {
+		if ((*blobp = malloc(len)) == NULL) {
+			ret = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		memcpy(*blobp, sshbuf_ptr(b), len);
+	}
+	ret = 0;
+ out:
+	sshbuf_free(b);
+	return ret;
+}
+
+int
+sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
+{
+	return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+int
+sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
+{
+	return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+int
+sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg,
+    u_char **retp, size_t *lenp)
+{
+	u_char *blob = NULL, *ret = NULL;
+	size_t blob_len = 0;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	if (retp != NULL)
+		*retp = NULL;
+	if (lenp != NULL)
+		*lenp = 0;
+	if (ssh_digest_bytes(dgst_alg) == 0) {
+		r = SSH_ERR_INVALID_ARGUMENT;
+		goto out;
+	}
+	if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT))
+	    != 0)
+		goto out;
+	if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = ssh_digest_memory(dgst_alg, blob, blob_len,
+	    ret, SSH_DIGEST_MAX_LENGTH)) != 0)
+		goto out;
+	/* success */
+	if (retp != NULL) {
+		*retp = ret;
+		ret = NULL;
+	}
+	if (lenp != NULL)
+		*lenp = ssh_digest_bytes(dgst_alg);
+	r = 0;
+ out:
+	free(ret);
+	if (blob != NULL)
+		freezero(blob, blob_len);
+	return r;
+}
+
+static char *
+fingerprint_b64(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
+{
+	char *ret;
+	size_t plen = strlen(alg) + 1;
+	size_t rlen = ((dgst_raw_len + 2) / 3) * 4 + plen + 1;
+
+	if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL)
+		return NULL;
+	strlcpy(ret, alg, rlen);
+	strlcat(ret, ":", rlen);
+	if (dgst_raw_len == 0)
+		return ret;
+	if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) {
+		freezero(ret, rlen);
+		return NULL;
+	}
+	/* Trim padding characters from end */
+	ret[strcspn(ret, "=")] = '\0';
+	return ret;
+}
+
+static char *
+fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len)
+{
+	char *retval, hex[5];
+	size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2;
+
+	if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL)
+		return NULL;
+	strlcpy(retval, alg, rlen);
+	strlcat(retval, ":", rlen);
+	for (i = 0; i < dgst_raw_len; i++) {
+		snprintf(hex, sizeof(hex), "%s%02x",
+		    i > 0 ? ":" : "", dgst_raw[i]);
+		strlcat(retval, hex, rlen);
+	}
+	return retval;
+}
+
+static char *
+fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len)
+{
+	char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' };
+	char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm',
+	    'n', 'p', 'r', 's', 't', 'v', 'z', 'x' };
+	u_int i, j = 0, rounds, seed = 1;
+	char *retval;
+
+	rounds = (dgst_raw_len / 2) + 1;
+	if ((retval = calloc(rounds, 6)) == NULL)
+		return NULL;
+	retval[j++] = 'x';
+	for (i = 0; i < rounds; i++) {
+		u_int idx0, idx1, idx2, idx3, idx4;
+		if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) {
+			idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) +
+			    seed) % 6;
+			idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15;
+			idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) +
+			    (seed / 6)) % 6;
+			retval[j++] = vowels[idx0];
+			retval[j++] = consonants[idx1];
+			retval[j++] = vowels[idx2];
+			if ((i + 1) < rounds) {
+				idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15;
+				idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15;
+				retval[j++] = consonants[idx3];
+				retval[j++] = '-';
+				retval[j++] = consonants[idx4];
+				seed = ((seed * 5) +
+				    ((((u_int)(dgst_raw[2 * i])) * 7) +
+				    ((u_int)(dgst_raw[(2 * i) + 1])))) % 36;
+			}
+		} else {
+			idx0 = seed % 6;
+			idx1 = 16;
+			idx2 = seed / 6;
+			retval[j++] = vowels[idx0];
+			retval[j++] = consonants[idx1];
+			retval[j++] = vowels[idx2];
+		}
+	}
+	retval[j++] = 'x';
+	retval[j++] = '\0';
+	return retval;
+}
+
+/*
+ * Draw an ASCII-Art representing the fingerprint so human brain can
+ * profit from its built-in pattern recognition ability.
+ * This technique is called "random art" and can be found in some
+ * scientific publications like this original paper:
+ *
+ * "Hash Visualization: a New Technique to improve Real-World Security",
+ * Perrig A. and Song D., 1999, International Workshop on Cryptographic
+ * Techniques and E-Commerce (CrypTEC '99)
+ * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
+ *
+ * The subject came up in a talk by Dan Kaminsky, too.
+ *
+ * If you see the picture is different, the key is different.
+ * If the picture looks the same, you still know nothing.
+ *
+ * The algorithm used here is a worm crawling over a discrete plane,
+ * leaving a trace (augmenting the field) everywhere it goes.
+ * Movement is taken from dgst_raw 2bit-wise.  Bumping into walls
+ * makes the respective movement vector be ignored for this turn.
+ * Graphs are not unambiguous, because circles in graphs can be
+ * walked in either direction.
+ */
+
+/*
+ * Field sizes for the random art.  Have to be odd, so the starting point
+ * can be in the exact middle of the picture, and FLDBASE should be >=8 .
+ * Else pictures would be too dense, and drawing the frame would
+ * fail, too, because the key type would not fit in anymore.
+ */
+#define	FLDBASE		8
+#define	FLDSIZE_Y	(FLDBASE + 1)
+#define	FLDSIZE_X	(FLDBASE * 2 + 1)
+static char *
+fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len,
+    const struct sshkey *k)
+{
+	/*
+	 * Chars to be used after each other every time the worm
+	 * intersects with itself.  Matter of taste.
+	 */
+	char	*augmentation_string = " .o+=*BOX@%&#/^SE";
+	char	*retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X];
+	u_char	 field[FLDSIZE_X][FLDSIZE_Y];
+	size_t	 i, tlen, hlen;
+	u_int	 b;
+	int	 x, y, r;
+	size_t	 len = strlen(augmentation_string) - 1;
+
+	if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL)
+		return NULL;
+
+	/* initialize field */
+	memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char));
+	x = FLDSIZE_X / 2;
+	y = FLDSIZE_Y / 2;
+
+	/* process raw key */
+	for (i = 0; i < dgst_raw_len; i++) {
+		int input;
+		/* each byte conveys four 2-bit move commands */
+		input = dgst_raw[i];
+		for (b = 0; b < 4; b++) {
+			/* evaluate 2 bit, rest is shifted later */
+			x += (input & 0x1) ? 1 : -1;
+			y += (input & 0x2) ? 1 : -1;
+
+			/* assure we are still in bounds */
+			x = MAXIMUM(x, 0);
+			y = MAXIMUM(y, 0);
+			x = MINIMUM(x, FLDSIZE_X - 1);
+			y = MINIMUM(y, FLDSIZE_Y - 1);
+
+			/* augment the field */
+			if (field[x][y] < len - 2)
+				field[x][y]++;
+			input = input >> 2;
+		}
+	}
+
+	/* mark starting point and end point*/
+	field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1;
+	field[x][y] = len;
+
+	/* assemble title */
+	r = snprintf(title, sizeof(title), "[%s %u]",
+		sshkey_type(k), sshkey_size(k));
+	/* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */
+	if (r < 0 || r > (int)sizeof(title))
+		r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k));
+	tlen = (r <= 0) ? 0 : strlen(title);
+
+	/* assemble hash ID. */
+	r = snprintf(hash, sizeof(hash), "[%s]", alg);
+	hlen = (r <= 0) ? 0 : strlen(hash);
+
+	/* output upper border */
+	p = retval;
+	*p++ = '+';
+	for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++)
+		*p++ = '-';
+	memcpy(p, title, tlen);
+	p += tlen;
+	for (i += tlen; i < FLDSIZE_X; i++)
+		*p++ = '-';
+	*p++ = '+';
+	*p++ = '\n';
+
+	/* output content */
+	for (y = 0; y < FLDSIZE_Y; y++) {
+		*p++ = '|';
+		for (x = 0; x < FLDSIZE_X; x++)
+			*p++ = augmentation_string[MINIMUM(field[x][y], len)];
+		*p++ = '|';
+		*p++ = '\n';
+	}
+
+	/* output lower border */
+	*p++ = '+';
+	for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++)
+		*p++ = '-';
+	memcpy(p, hash, hlen);
+	p += hlen;
+	for (i += hlen; i < FLDSIZE_X; i++)
+		*p++ = '-';
+	*p++ = '+';
+
+	return retval;
+}
+
+char *
+sshkey_fingerprint(const struct sshkey *k, int dgst_alg,
+    enum sshkey_fp_rep dgst_rep)
+{
+	char *retval = NULL;
+	u_char *dgst_raw;
+	size_t dgst_raw_len;
+
+	if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0)
+		return NULL;
+	switch (dgst_rep) {
+	case SSH_FP_DEFAULT:
+		if (dgst_alg == SSH_DIGEST_MD5) {
+			retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
+			    dgst_raw, dgst_raw_len);
+		} else {
+			retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
+			    dgst_raw, dgst_raw_len);
+		}
+		break;
+	case SSH_FP_HEX:
+		retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg),
+		    dgst_raw, dgst_raw_len);
+		break;
+	case SSH_FP_BASE64:
+		retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg),
+		    dgst_raw, dgst_raw_len);
+		break;
+	case SSH_FP_BUBBLEBABBLE:
+		retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len);
+		break;
+	case SSH_FP_RANDOMART:
+		retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg),
+		    dgst_raw, dgst_raw_len, k);
+		break;
+	default:
+		freezero(dgst_raw, dgst_raw_len);
+		return NULL;
+	}
+	freezero(dgst_raw, dgst_raw_len);
+	return retval;
+}
+
+static int
+peek_type_nid(const char *s, size_t l, int *nid)
+{
+	const struct sshkey_impl *impl;
+	int i;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		impl = keyimpls[i];
+		if (impl->name == NULL || strlen(impl->name) != l)
+			continue;
+		if (memcmp(s, impl->name, l) == 0) {
+			*nid = -1;
+			if (key_type_is_ecdsa_variant(impl->type))
+				*nid = impl->nid;
+			return impl->type;
+		}
+	}
+	return KEY_UNSPEC;
+}
+
+/* XXX this can now be made const char * */
+int
+sshkey_read(struct sshkey *ret, char **cpp)
+{
+	struct sshkey *k;
+	char *cp, *blobcopy;
+	size_t space;
+	int r, type, curve_nid = -1;
+	struct sshbuf *blob;
+
+	if (ret == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (ret->type != KEY_UNSPEC && sshkey_impl_from_type(ret->type) == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	/* Decode type */
+	cp = *cpp;
+	space = strcspn(cp, " \t");
+	if (space == strlen(cp))
+		return SSH_ERR_INVALID_FORMAT;
+	if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC)
+		return SSH_ERR_INVALID_FORMAT;
+
+	/* skip whitespace */
+	for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
+		;
+	if (*cp == '\0')
+		return SSH_ERR_INVALID_FORMAT;
+	if (ret->type != KEY_UNSPEC && ret->type != type)
+		return SSH_ERR_KEY_TYPE_MISMATCH;
+	if ((blob = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+
+	/* find end of keyblob and decode */
+	space = strcspn(cp, " \t");
+	if ((blobcopy = strndup(cp, space)) == NULL) {
+		sshbuf_free(blob);
+		return SSH_ERR_ALLOC_FAIL;
+	}
+	if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) {
+		free(blobcopy);
+		sshbuf_free(blob);
+		return r;
+	}
+	free(blobcopy);
+	if ((r = sshkey_fromb(blob, &k)) != 0) {
+		sshbuf_free(blob);
+		return r;
+	}
+	sshbuf_free(blob);
+
+	/* skip whitespace and leave cp at start of comment */
+	for (cp += space; *cp == ' ' || *cp == '\t'; cp++)
+		;
+
+	/* ensure type of blob matches type at start of line */
+	if (k->type != type) {
+		sshkey_free(k);
+		return SSH_ERR_KEY_TYPE_MISMATCH;
+	}
+	if (key_type_is_ecdsa_variant(type) && curve_nid != k->ecdsa_nid) {
+		sshkey_free(k);
+		return SSH_ERR_EC_CURVE_MISMATCH;
+	}
+
+	/* Fill in ret from parsed key */
+	sshkey_free_contents(ret);
+	*ret = *k;
+	freezero(k, sizeof(*k));
+
+	/* success */
+	*cpp = cp;
+	return 0;
+}
+
+int
+sshkey_to_base64(const struct sshkey *key, char **b64p)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+	struct sshbuf *b = NULL;
+	char *uu = NULL;
+
+	if (b64p != NULL)
+		*b64p = NULL;
+	if ((b = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshkey_putb(key, b)) != 0)
+		goto out;
+	if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	/* Success */
+	if (b64p != NULL) {
+		*b64p = uu;
+		uu = NULL;
+	}
+	r = 0;
+ out:
+	sshbuf_free(b);
+	free(uu);
+	return r;
+}
+
+int
+sshkey_format_text(const struct sshkey *key, struct sshbuf *b)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+	char *uu = NULL;
+
+	if ((r = sshkey_to_base64(key, &uu)) != 0)
+		goto out;
+	if ((r = sshbuf_putf(b, "%s %s",
+	    sshkey_ssh_name(key), uu)) != 0)
+		goto out;
+	r = 0;
+ out:
+	free(uu);
+	return r;
+}
+
+int
+sshkey_write(const struct sshkey *key, FILE *f)
+{
+	struct sshbuf *b = NULL;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	if ((b = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshkey_format_text(key, b)) != 0)
+		goto out;
+	if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) {
+		if (feof(f))
+			errno = EPIPE;
+		r = SSH_ERR_SYSTEM_ERROR;
+		goto out;
+	}
+	/* Success */
+	r = 0;
+ out:
+	sshbuf_free(b);
+	return r;
+}
+
+const char *
+sshkey_cert_type(const struct sshkey *k)
+{
+	switch (k->cert->type) {
+	case SSH2_CERT_TYPE_USER:
+		return "user";
+	case SSH2_CERT_TYPE_HOST:
+		return "host";
+	default:
+		return "unknown";
+	}
+}
+
+int
+sshkey_check_rsa_length(const struct sshkey *k, int min_size)
+{
+#ifdef WITH_OPENSSL
+	const BIGNUM *rsa_n;
+	int nbits;
+
+	if (k == NULL || k->rsa == NULL ||
+	    (k->type != KEY_RSA && k->type != KEY_RSA_CERT))
+		return 0;
+	RSA_get0_key(k->rsa, &rsa_n, NULL, NULL);
+	nbits = BN_num_bits(rsa_n);
+	if (nbits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
+	    (min_size > 0 && nbits < min_size))
+		return SSH_ERR_KEY_LENGTH;
+#endif /* WITH_OPENSSL */
+	return 0;
+}
+
+#ifdef WITH_OPENSSL
+# ifdef OPENSSL_HAS_ECC
+int
+sshkey_ecdsa_key_to_nid(EC_KEY *k)
+{
+	EC_GROUP *eg;
+	int nids[] = {
+		NID_X9_62_prime256v1,
+		NID_secp384r1,
+#  ifdef OPENSSL_HAS_NISTP521
+		NID_secp521r1,
+#  endif /* OPENSSL_HAS_NISTP521 */
+		-1
+	};
+	int nid;
+	u_int i;
+	const EC_GROUP *g = EC_KEY_get0_group(k);
+
+	/*
+	 * The group may be stored in a ASN.1 encoded private key in one of two
+	 * ways: as a "named group", which is reconstituted by ASN.1 object ID
+	 * or explicit group parameters encoded into the key blob. Only the
+	 * "named group" case sets the group NID for us, but we can figure
+	 * it out for the other case by comparing against all the groups that
+	 * are supported.
+	 */
+	if ((nid = EC_GROUP_get_curve_name(g)) > 0)
+		return nid;
+	for (i = 0; nids[i] != -1; i++) {
+		if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL)
+			return -1;
+		if (EC_GROUP_cmp(g, eg, NULL) == 0)
+			break;
+		EC_GROUP_free(eg);
+	}
+	if (nids[i] != -1) {
+		/* Use the group with the NID attached */
+		EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE);
+		if (EC_KEY_set_group(k, eg) != 1) {
+			EC_GROUP_free(eg);
+			return -1;
+		}
+	}
+	return nids[i];
+}
+# endif /* OPENSSL_HAS_ECC */
+#endif /* WITH_OPENSSL */
+
+int
+sshkey_generate(int type, u_int bits, struct sshkey **keyp)
+{
+	struct sshkey *k;
+	int ret = SSH_ERR_INTERNAL_ERROR;
+	const struct sshkey_impl *impl;
+
+	if (keyp == NULL || sshkey_type_is_cert(type))
+		return SSH_ERR_INVALID_ARGUMENT;
+	*keyp = NULL;
+	if ((impl = sshkey_impl_from_type(type)) == NULL)
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	if (impl->funcs->generate == NULL)
+		return SSH_ERR_FEATURE_UNSUPPORTED;
+	if ((k = sshkey_new(KEY_UNSPEC)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	k->type = type;
+	if ((ret = impl->funcs->generate(k, bits)) != 0) {
+		sshkey_free(k);
+		return ret;
+	}
+	/* success */
+	*keyp = k;
+	return 0;
+}
+
+int
+sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key)
+{
+	u_int i;
+	const struct sshkey_cert *from;
+	struct sshkey_cert *to;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	if (to_key == NULL || (from = from_key->cert) == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	if ((to = cert_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+
+	if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 ||
+	    (r = sshbuf_putb(to->critical, from->critical)) != 0 ||
+	    (r = sshbuf_putb(to->extensions, from->extensions)) != 0)
+		goto out;
+
+	to->serial = from->serial;
+	to->type = from->type;
+	if (from->key_id == NULL)
+		to->key_id = NULL;
+	else if ((to->key_id = strdup(from->key_id)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	to->valid_after = from->valid_after;
+	to->valid_before = from->valid_before;
+	if (from->signature_key == NULL)
+		to->signature_key = NULL;
+	else if ((r = sshkey_from_private(from->signature_key,
+	    &to->signature_key)) != 0)
+		goto out;
+	if (from->signature_type != NULL &&
+	    (to->signature_type = strdup(from->signature_type)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) {
+		r = SSH_ERR_INVALID_ARGUMENT;
+		goto out;
+	}
+	if (from->nprincipals > 0) {
+		if ((to->principals = calloc(from->nprincipals,
+		    sizeof(*to->principals))) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		for (i = 0; i < from->nprincipals; i++) {
+			to->principals[i] = strdup(from->principals[i]);
+			if (to->principals[i] == NULL) {
+				to->nprincipals = i;
+				r = SSH_ERR_ALLOC_FAIL;
+				goto out;
+			}
+		}
+	}
+	to->nprincipals = from->nprincipals;
+
+	/* success */
+	cert_free(to_key->cert);
+	to_key->cert = to;
+	to = NULL;
+	r = 0;
+ out:
+	cert_free(to);
+	return r;
+}
+
+int
+sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to)
+{
+	/* Append security-key application string */
+	if ((to->sk_application = strdup(from->sk_application)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	return 0;
+}
+
+int
+sshkey_from_private(const struct sshkey *k, struct sshkey **pkp)
+{
+	struct sshkey *n = NULL;
+	int r = SSH_ERR_INTERNAL_ERROR;
+	const struct sshkey_impl *impl;
+
+	*pkp = NULL;
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	if ((n = sshkey_new(k->type)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = impl->funcs->copy_public(k, n)) != 0)
+		goto out;
+	if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0)
+		goto out;
+	/* success */
+	*pkp = n;
+	n = NULL;
+	r = 0;
+ out:
+	sshkey_free(n);
+	return r;
+}
+
+int
+sshkey_is_shielded(struct sshkey *k)
+{
+	return k != NULL && k->shielded_private != NULL;
+}
+
+int
+sshkey_shield_private(struct sshkey *k)
+{
+	struct sshbuf *prvbuf = NULL;
+	u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH];
+	struct sshcipher_ctx *cctx = NULL;
+	const struct sshcipher *cipher;
+	size_t i, enclen = 0;
+	struct sshkey *kswap = NULL, tmp;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k));
+#endif
+	if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) {
+		r = SSH_ERR_INVALID_ARGUMENT;
+		goto out;
+	}
+	if (cipher_keylen(cipher) + cipher_ivlen(cipher) >
+	    ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) {
+		r = SSH_ERR_INTERNAL_ERROR;
+		goto out;
+	}
+
+	/* Prepare a random pre-key, and from it an ephemeral key */
+	if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN);
+	if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH,
+	    prekey, SSHKEY_SHIELD_PREKEY_LEN,
+	    keyiv, SSH_DIGEST_MAX_LENGTH)) != 0)
+		goto out;
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: key+iv\n", __func__);
+	sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH),
+	    stderr);
+#endif
+	if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher),
+	    keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0)
+		goto out;
+
+	/* Serialise and encrypt the private key using the ephemeral key */
+	if ((prvbuf = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0)
+		goto out;
+	if ((r = sshkey_private_serialize_opt(k, prvbuf,
+	    SSHKEY_SERIALIZE_SHIELD)) != 0)
+		goto out;
+	/* pad to cipher blocksize */
+	i = 0;
+	while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) {
+		if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0)
+			goto out;
+	}
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: serialised\n", __func__);
+	sshbuf_dump(prvbuf, stderr);
+#endif
+	/* encrypt */
+	enclen = sshbuf_len(prvbuf);
+	if ((enc = malloc(enclen)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = cipher_crypt(cctx, 0, enc,
+	    sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0)
+		goto out;
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: encrypted\n", __func__);
+	sshbuf_dump_data(enc, enclen, stderr);
+#endif
+
+	/* Make a scrubbed, public-only copy of our private key argument */
+	if ((r = sshkey_from_private(k, &kswap)) != 0)
+		goto out;
+
+	/* Swap the private key out (it will be destroyed below) */
+	tmp = *kswap;
+	*kswap = *k;
+	*k = tmp;
+
+	/* Insert the shielded key into our argument */
+	k->shielded_private = enc;
+	k->shielded_len = enclen;
+	k->shield_prekey = prekey;
+	k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN;
+	enc = prekey = NULL; /* transferred */
+	enclen = 0;
+
+	/* preserve key fields that are required for correct operation */
+	k->sk_flags = kswap->sk_flags;
+
+	/* success */
+	r = 0;
+
+ out:
+	/* XXX behaviour on error - invalidate original private key? */
+	cipher_free(cctx);
+	explicit_bzero(keyiv, sizeof(keyiv));
+	explicit_bzero(&tmp, sizeof(tmp));
+	freezero(enc, enclen);
+	freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN);
+	sshkey_free(kswap);
+	sshbuf_free(prvbuf);
+	return r;
+}
+
+/* Check deterministic padding after private key */
+static int
+private2_check_padding(struct sshbuf *decrypted)
+{
+	u_char pad;
+	size_t i;
+	int r;
+
+	i = 0;
+	while (sshbuf_len(decrypted)) {
+		if ((r = sshbuf_get_u8(decrypted, &pad)) != 0)
+			goto out;
+		if (pad != (++i & 0xff)) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+	}
+	/* success */
+	r = 0;
+ out:
+	explicit_bzero(&pad, sizeof(pad));
+	explicit_bzero(&i, sizeof(i));
+	return r;
+}
+
+int
+sshkey_unshield_private(struct sshkey *k)
+{
+	struct sshbuf *prvbuf = NULL;
+	u_char *cp, keyiv[SSH_DIGEST_MAX_LENGTH];
+	struct sshcipher_ctx *cctx = NULL;
+	const struct sshcipher *cipher;
+	struct sshkey *kswap = NULL, tmp;
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k));
+#endif
+	if (!sshkey_is_shielded(k))
+		return 0; /* nothing to do */
+
+	if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) {
+		r = SSH_ERR_INVALID_ARGUMENT;
+		goto out;
+	}
+	if (cipher_keylen(cipher) + cipher_ivlen(cipher) >
+	    ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) {
+		r = SSH_ERR_INTERNAL_ERROR;
+		goto out;
+	}
+	/* check size of shielded key blob */
+	if (k->shielded_len < cipher_blocksize(cipher) ||
+	    (k->shielded_len % cipher_blocksize(cipher)) != 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* Calculate the ephemeral key from the prekey */
+	if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH,
+	    k->shield_prekey, k->shield_prekey_len,
+	    keyiv, SSH_DIGEST_MAX_LENGTH)) != 0)
+		goto out;
+	if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher),
+	    keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0)
+		goto out;
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: key+iv\n", __func__);
+	sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH),
+	    stderr);
+#endif
+
+	/* Decrypt and parse the shielded private key using the ephemeral key */
+	if ((prvbuf = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0)
+		goto out;
+	/* decrypt */
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: encrypted\n", __func__);
+	sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr);
+#endif
+	if ((r = cipher_crypt(cctx, 0, cp,
+	    k->shielded_private, k->shielded_len, 0, 0)) != 0)
+		goto out;
+#ifdef DEBUG_PK
+	fprintf(stderr, "%s: serialised\n", __func__);
+	sshbuf_dump(prvbuf, stderr);
+#endif
+	/* Parse private key */
+	if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0)
+		goto out;
+
+	if ((r = private2_check_padding(prvbuf)) != 0)
+		goto out;
+
+	/* Swap the parsed key back into place */
+	tmp = *kswap;
+	*kswap = *k;
+	*k = tmp;
+
+	/* success */
+	r = 0;
+
+ out:
+	cipher_free(cctx);
+	explicit_bzero(keyiv, sizeof(keyiv));
+	explicit_bzero(&tmp, sizeof(tmp));
+	sshkey_free(kswap);
+	sshbuf_free(prvbuf);
+	return r;
+}
+
+static int
+cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf)
+{
+	struct sshbuf *principals = NULL, *crit = NULL;
+	struct sshbuf *exts = NULL, *ca = NULL;
+	u_char *sig = NULL;
+	size_t signed_len = 0, slen = 0, kidlen = 0;
+	int ret = SSH_ERR_INTERNAL_ERROR;
+
+	/* Copy the entire key blob for verification and later serialisation */
+	if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0)
+		return ret;
+
+	/* Parse body of certificate up to signature */
+	if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 ||
+	    (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 ||
+	    (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 ||
+	    (ret = sshbuf_froms(b, &principals)) != 0 ||
+	    (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 ||
+	    (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 ||
+	    (ret = sshbuf_froms(b, &crit)) != 0 ||
+	    (ret = sshbuf_froms(b, &exts)) != 0 ||
+	    (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 ||
+	    (ret = sshbuf_froms(b, &ca)) != 0) {
+		/* XXX debug print error for ret */
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* Signature is left in the buffer so we can calculate this length */
+	signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b);
+
+	if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	if (key->cert->type != SSH2_CERT_TYPE_USER &&
+	    key->cert->type != SSH2_CERT_TYPE_HOST) {
+		ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE;
+		goto out;
+	}
+
+	/* Parse principals section */
+	while (sshbuf_len(principals) > 0) {
+		char *principal = NULL;
+		char **oprincipals = NULL;
+
+		if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) {
+			ret = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		if ((ret = sshbuf_get_cstring(principals, &principal,
+		    NULL)) != 0) {
+			ret = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		oprincipals = key->cert->principals;
+		key->cert->principals = recallocarray(key->cert->principals,
+		    key->cert->nprincipals, key->cert->nprincipals + 1,
+		    sizeof(*key->cert->principals));
+		if (key->cert->principals == NULL) {
+			free(principal);
+			key->cert->principals = oprincipals;
+			ret = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		key->cert->principals[key->cert->nprincipals++] = principal;
+	}
+
+	/*
+	 * Stash a copies of the critical options and extensions sections
+	 * for later use.
+	 */
+	if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 ||
+	    (exts != NULL &&
+	    (ret = sshbuf_putb(key->cert->extensions, exts)) != 0))
+		goto out;
+
+	/*
+	 * Validate critical options and extensions sections format.
+	 */
+	while (sshbuf_len(crit) != 0) {
+		if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 ||
+		    (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) {
+			sshbuf_reset(key->cert->critical);
+			ret = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+	}
+	while (exts != NULL && sshbuf_len(exts) != 0) {
+		if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 ||
+		    (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) {
+			sshbuf_reset(key->cert->extensions);
+			ret = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+	}
+
+	/* Parse CA key and check signature */
+	if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) {
+		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
+		goto out;
+	}
+	if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) {
+		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
+		goto out;
+	}
+	if ((ret = sshkey_verify(key->cert->signature_key, sig, slen,
+	    sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0, NULL)) != 0)
+		goto out;
+	if ((ret = sshkey_get_sigtype(sig, slen,
+	    &key->cert->signature_type)) != 0)
+		goto out;
+
+	/* Success */
+	ret = 0;
+ out:
+	sshbuf_free(ca);
+	sshbuf_free(crit);
+	sshbuf_free(exts);
+	sshbuf_free(principals);
+	free(sig);
+	return ret;
+}
+
+int
+sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key)
+{
+	/* Parse additional security-key application string */
+	if (sshbuf_get_cstring(b, &key->sk_application, NULL) != 0)
+		return SSH_ERR_INVALID_FORMAT;
+	return 0;
+}
+
+static int
+sshkey_from_blob_internal(struct sshbuf *b, struct sshkey **keyp,
+    int allow_cert)
+{
+	int type, ret = SSH_ERR_INTERNAL_ERROR;
+	char *ktype = NULL;
+	struct sshkey *key = NULL;
+	struct sshbuf *copy;
+	const struct sshkey_impl *impl;
+
+#ifdef DEBUG_PK /* XXX */
+	sshbuf_dump(b, stderr);
+#endif
+	if (keyp != NULL)
+		*keyp = NULL;
+	if ((copy = sshbuf_fromb(b)) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (sshbuf_get_cstring(b, &ktype, NULL) != 0) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	type = sshkey_type_from_name(ktype);
+	if (!allow_cert && sshkey_type_is_cert(type)) {
+		ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
+		goto out;
+	}
+	if ((impl = sshkey_impl_from_type(type)) == NULL) {
+		ret = SSH_ERR_KEY_TYPE_UNKNOWN;
+		goto out;
+	}
+	if ((key = sshkey_new(type)) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (sshkey_type_is_cert(type)) {
+		/* Skip nonce that preceeds all certificates */
+		if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
+			ret = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+	}
+	if ((ret = impl->funcs->deserialize_public(ktype, b, key)) != 0)
+		goto out;
+
+	/* Parse certificate potion */
+	if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0)
+		goto out;
+
+	if (key != NULL && sshbuf_len(b) != 0) {
+		ret = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	ret = 0;
+	if (keyp != NULL) {
+		*keyp = key;
+		key = NULL;
+	}
+ out:
+	sshbuf_free(copy);
+	sshkey_free(key);
+	free(ktype);
+	return ret;
+}
+
+int
+sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp)
+{
+	struct sshbuf *b;
+	int r;
+
+	if ((b = sshbuf_from(blob, blen)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	r = sshkey_from_blob_internal(b, keyp, 1);
+	sshbuf_free(b);
+	return r;
+}
+
+int
+sshkey_fromb(struct sshbuf *b, struct sshkey **keyp)
+{
+	return sshkey_from_blob_internal(b, keyp, 1);
+}
+
+int
+sshkey_froms(struct sshbuf *buf, struct sshkey **keyp)
+{
+	struct sshbuf *b;
+	int r;
+
+	if ((r = sshbuf_froms(buf, &b)) != 0)
+		return r;
+	r = sshkey_from_blob_internal(b, keyp, 1);
+	sshbuf_free(b);
+	return r;
+}
+
+int
+sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep)
+{
+	int r;
+	struct sshbuf *b = NULL;
+	char *sigtype = NULL;
+
+	if (sigtypep != NULL)
+		*sigtypep = NULL;
+	if ((b = sshbuf_from(sig, siglen)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0)
+		goto out;
+	/* success */
+	if (sigtypep != NULL) {
+		*sigtypep = sigtype;
+		sigtype = NULL;
+	}
+	r = 0;
+ out:
+	free(sigtype);
+	sshbuf_free(b);
+	return r;
+}
+
+/*
+ *
+ * Checks whether a certificate's signature type is allowed.
+ * Returns 0 (success) if the certificate signature type appears in the
+ * "allowed" pattern-list, or the key is not a certificate to begin with.
+ * Otherwise returns a ssherr.h code.
+ */
+int
+sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed)
+{
+	if (key == NULL || allowed == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (!sshkey_type_is_cert(key->type))
+		return 0;
+	if (key->cert == NULL || key->cert->signature_type == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1)
+		return SSH_ERR_SIGN_ALG_UNSUPPORTED;
+	return 0;
+}
+
+/*
+ * Returns the expected signature algorithm for a given public key algorithm.
+ */
+const char *
+sshkey_sigalg_by_name(const char *name)
+{
+	const struct sshkey_impl *impl;
+	int i;
+
+	for (i = 0; keyimpls[i] != NULL; i++) {
+		impl = keyimpls[i];
+		if (strcmp(impl->name, name) != 0)
+			continue;
+		if (impl->sigalg != NULL)
+			return impl->sigalg;
+		if (!impl->cert)
+			return impl->name;
+		return sshkey_ssh_name_from_type_nid(
+		    sshkey_type_plain(impl->type), impl->nid);
+	}
+	return NULL;
+}
+
+/*
+ * Verifies that the signature algorithm appearing inside the signature blob
+ * matches that which was requested.
+ */
+int
+sshkey_check_sigtype(const u_char *sig, size_t siglen,
+    const char *requested_alg)
+{
+	const char *expected_alg;
+	char *sigtype = NULL;
+	int r;
+
+	if (requested_alg == NULL)
+		return 0;
+	if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0)
+		return r;
+	r = strcmp(expected_alg, sigtype) == 0;
+	free(sigtype);
+	return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED;
+}
+
+int
+sshkey_sign(struct sshkey *key,
+    u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen,
+    const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)
+{
+	int was_shielded = sshkey_is_shielded(key);
+	int r2, r = SSH_ERR_INTERNAL_ERROR;
+	const struct sshkey_impl *impl;
+
+	if (sigp != NULL)
+		*sigp = NULL;
+	if (lenp != NULL)
+		*lenp = 0;
+	if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if ((impl = sshkey_impl_from_key(key)) == NULL)
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	if ((r = sshkey_unshield_private(key)) != 0)
+		return r;
+	if (sshkey_is_sk(key)) {
+		r = sshsk_sign(sk_provider, key, sigp, lenp, data,
+		    datalen, compat, sk_pin);
+	} else {
+		if (impl->funcs->sign == NULL)
+			r = SSH_ERR_SIGN_ALG_UNSUPPORTED;
+		else {
+			r = impl->funcs->sign(key, sigp, lenp, data, datalen,
+			    alg, sk_provider, sk_pin, compat);
+		 }
+	}
+	if (was_shielded && (r2 = sshkey_shield_private(key)) != 0)
+		return r2;
+	return r;
+}
+
+/*
+ * ssh_key_verify returns 0 for a correct signature  and < 0 on error.
+ * If "alg" specified, then the signature must use that algorithm.
+ */
+int
+sshkey_verify(const struct sshkey *key,
+    const u_char *sig, size_t siglen,
+    const u_char *data, size_t dlen, const char *alg, u_int compat,
+    struct sshkey_sig_details **detailsp)
+{
+	const struct sshkey_impl *impl;
+
+	if (detailsp != NULL)
+		*detailsp = NULL;
+	if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if ((impl = sshkey_impl_from_key(key)) == NULL)
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	return impl->funcs->verify(key, sig, siglen, data, dlen,
+	    alg, compat, detailsp);
+}
+
+/* Convert a plain key to their _CERT equivalent */
+int
+sshkey_to_certified(struct sshkey *k)
+{
+	int newtype;
+
+	if ((newtype = sshkey_type_certified(k->type)) == -1)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if ((k->cert = cert_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	k->type = newtype;
+	return 0;
+}
+
+/* Convert a certificate to its raw key equivalent */
+int
+sshkey_drop_cert(struct sshkey *k)
+{
+	if (!sshkey_type_is_cert(k->type))
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	cert_free(k->cert);
+	k->cert = NULL;
+	k->type = sshkey_type_plain(k->type);
+	return 0;
+}
+
+/* Sign a certified key, (re-)generating the signed certblob. */
+int
+sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg,
+    const char *sk_provider, const char *sk_pin,
+    sshkey_certify_signer *signer, void *signer_ctx)
+{
+	const struct sshkey_impl *impl;
+	struct sshbuf *principals = NULL;
+	u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32];
+	size_t i, ca_len, sig_len;
+	int ret = SSH_ERR_INTERNAL_ERROR;
+	struct sshbuf *cert = NULL;
+	char *sigtype = NULL;
+
+	if (k == NULL || k->cert == NULL ||
+	    k->cert->certblob == NULL || ca == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (!sshkey_is_cert(k))
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	if (!sshkey_type_is_valid_ca(ca->type))
+		return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
+	if ((impl = sshkey_impl_from_key(k)) == NULL)
+		return SSH_ERR_INTERNAL_ERROR;
+
+	/*
+	 * If no alg specified as argument but a signature_type was set,
+	 * then prefer that. If both were specified, then they must match.
+	 */
+	if (alg == NULL)
+		alg = k->cert->signature_type;
+	else if (k->cert->signature_type != NULL &&
+	    strcmp(alg, k->cert->signature_type) != 0)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	/*
+	 * If no signing algorithm or signature_type was specified and we're
+	 * using a RSA key, then default to a good signature algorithm.
+	 */
+	if (alg == NULL && ca->type == KEY_RSA)
+		alg = "rsa-sha2-512";
+
+	if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0)
+		return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY;
+
+	cert = k->cert->certblob; /* for readability */
+	sshbuf_reset(cert);
+	if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0)
+		goto out;
+
+	/* -v01 certs put nonce first */
+	arc4random_buf(&nonce, sizeof(nonce));
+	if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0)
+		goto out;
+
+	/* Public key next */
+	if ((ret = impl->funcs->serialize_public(k, cert,
+	    SSHKEY_SERIALIZE_DEFAULT)) != 0)
+		goto out;
+
+	/* Then remaining cert fields */
+	if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 ||
+	    (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 ||
+	    (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0)
+		goto out;
+
+	if ((principals = sshbuf_new()) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	for (i = 0; i < k->cert->nprincipals; i++) {
+		if ((ret = sshbuf_put_cstring(principals,
+		    k->cert->principals[i])) != 0)
+			goto out;
+	}
+	if ((ret = sshbuf_put_stringb(cert, principals)) != 0 ||
+	    (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 ||
+	    (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 ||
+	    (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 ||
+	    (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 ||
+	    (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */
+	    (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0)
+		goto out;
+
+	/* Sign the whole mess */
+	if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert),
+	    sshbuf_len(cert), alg, sk_provider, sk_pin, 0, signer_ctx)) != 0)
+		goto out;
+	/* Check and update signature_type against what was actually used */
+	if ((ret = sshkey_get_sigtype(sig_blob, sig_len, &sigtype)) != 0)
+		goto out;
+	if (alg != NULL && strcmp(alg, sigtype) != 0) {
+		ret = SSH_ERR_SIGN_ALG_UNSUPPORTED;
+		goto out;
+	}
+	if (k->cert->signature_type == NULL) {
+		k->cert->signature_type = sigtype;
+		sigtype = NULL;
+	}
+	/* Append signature and we are done */
+	if ((ret = sshbuf_put_string(cert, sig_blob, sig_len)) != 0)
+		goto out;
+	ret = 0;
+ out:
+	if (ret != 0)
+		sshbuf_reset(cert);
+	free(sig_blob);
+	free(ca_blob);
+	free(sigtype);
+	sshbuf_free(principals);
+	return ret;
+}
+
+static int
+default_key_sign(struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen,
+    const char *alg, const char *sk_provider, const char *sk_pin,
+    u_int compat, void *ctx)
+{
+	if (ctx != NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	return sshkey_sign(key, sigp, lenp, data, datalen, alg,
+	    sk_provider, sk_pin, compat);
+}
+
+int
+sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg,
+    const char *sk_provider, const char *sk_pin)
+{
+	return sshkey_certify_custom(k, ca, alg, sk_provider, sk_pin,
+	    default_key_sign, NULL);
+}
+
+int
+sshkey_cert_check_authority(const struct sshkey *k,
+    int want_host, int require_principal, int wildcard_pattern,
+    uint64_t verify_time, const char *name, const char **reason)
+{
+	u_int i, principal_matches;
+
+	if (reason == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (!sshkey_is_cert(k)) {
+		*reason = "Key is not a certificate";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	if (want_host) {
+		if (k->cert->type != SSH2_CERT_TYPE_HOST) {
+			*reason = "Certificate invalid: not a host certificate";
+			return SSH_ERR_KEY_CERT_INVALID;
+		}
+	} else {
+		if (k->cert->type != SSH2_CERT_TYPE_USER) {
+			*reason = "Certificate invalid: not a user certificate";
+			return SSH_ERR_KEY_CERT_INVALID;
+		}
+	}
+	if (verify_time < k->cert->valid_after) {
+		*reason = "Certificate invalid: not yet valid";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	if (verify_time >= k->cert->valid_before) {
+		*reason = "Certificate invalid: expired";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	if (k->cert->nprincipals == 0) {
+		if (require_principal) {
+			*reason = "Certificate lacks principal list";
+			return SSH_ERR_KEY_CERT_INVALID;
+		}
+	} else if (name != NULL) {
+		principal_matches = 0;
+		for (i = 0; i < k->cert->nprincipals; i++) {
+			if (wildcard_pattern) {
+				if (match_pattern(k->cert->principals[i],
+				    name)) {
+					principal_matches = 1;
+					break;
+				}
+			} else if (strcmp(name, k->cert->principals[i]) == 0) {
+				principal_matches = 1;
+				break;
+			}
+		}
+		if (!principal_matches) {
+			*reason = "Certificate invalid: name is not a listed "
+			    "principal";
+			return SSH_ERR_KEY_CERT_INVALID;
+		}
+	}
+	return 0;
+}
+
+int
+sshkey_cert_check_authority_now(const struct sshkey *k,
+    int want_host, int require_principal, int wildcard_pattern,
+    const char *name, const char **reason)
+{
+	time_t now;
+
+	if ((now = time(NULL)) < 0) {
+		/* yikes - system clock before epoch! */
+		*reason = "Certificate invalid: not yet valid";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	return sshkey_cert_check_authority(k, want_host, require_principal,
+	    wildcard_pattern, (uint64_t)now, name, reason);
+}
+
+int
+sshkey_cert_check_host(const struct sshkey *key, const char *host,
+    int wildcard_principals, const char *ca_sign_algorithms,
+    const char **reason)
+{
+	int r;
+
+	if ((r = sshkey_cert_check_authority_now(key, 1, 0, wildcard_principals,
+	    host, reason)) != 0)
+		return r;
+	if (sshbuf_len(key->cert->critical) != 0) {
+		*reason = "Certificate contains unsupported critical options";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	if (ca_sign_algorithms != NULL &&
+	    (r = sshkey_check_cert_sigtype(key, ca_sign_algorithms)) != 0) {
+		*reason = "Certificate signed with disallowed algorithm";
+		return SSH_ERR_KEY_CERT_INVALID;
+	}
+	return 0;
+}
+
+size_t
+sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l)
+{
+	char from[32], to[32], ret[128];
+
+	*from = *to = '\0';
+	if (cert->valid_after == 0 &&
+	    cert->valid_before == 0xffffffffffffffffULL)
+		return strlcpy(s, "forever", l);
+
+	if (cert->valid_after != 0)
+		format_absolute_time(cert->valid_after, from, sizeof(from));
+	if (cert->valid_before != 0xffffffffffffffffULL)
+		format_absolute_time(cert->valid_before, to, sizeof(to));
+
+	if (cert->valid_after == 0)
+		snprintf(ret, sizeof(ret), "before %s", to);
+	else if (cert->valid_before == 0xffffffffffffffffULL)
+		snprintf(ret, sizeof(ret), "after %s", from);
+	else
+		snprintf(ret, sizeof(ret), "from %s to %s", from, to);
+
+	return strlcpy(s, ret, l);
+}
+
+/* Common serialization for FIDO private keys */
+int
+sshkey_serialize_private_sk(const struct sshkey *key, struct sshbuf *b)
+{
+	int r;
+
+	if ((r = sshbuf_put_cstring(b, key->sk_application)) != 0 ||
+	    (r = sshbuf_put_u8(b, key->sk_flags)) != 0 ||
+	    (r = sshbuf_put_stringb(b, key->sk_key_handle)) != 0 ||
+	    (r = sshbuf_put_stringb(b, key->sk_reserved)) != 0)
+		return r;
+
+	return 0;
+}
+
+int
+sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
+    enum sshkey_serialize_rep opts)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+	int was_shielded = sshkey_is_shielded(key);
+	struct sshbuf *b = NULL;
+	const struct sshkey_impl *impl;
+
+	if ((impl = sshkey_impl_from_key(key)) == NULL)
+		return SSH_ERR_INTERNAL_ERROR;
+	if ((r = sshkey_unshield_private(key)) != 0)
+		return r;
+	if ((b = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0)
+		goto out;
+	if (sshkey_is_cert(key)) {
+		if (key->cert == NULL ||
+		    sshbuf_len(key->cert->certblob) == 0) {
+			r = SSH_ERR_INVALID_ARGUMENT;
+			goto out;
+		}
+		if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0)
+			goto out;
+	}
+	if ((r = impl->funcs->serialize_private(key, b, opts)) != 0)
+		goto out;
+
+	/*
+	 * success (but we still need to append the output to buf after
+	 * possibly re-shielding the private key)
+	 */
+	r = 0;
+ out:
+	if (was_shielded)
+		r = sshkey_shield_private(key);
+	if (r == 0)
+		r = sshbuf_putb(buf, b);
+	sshbuf_free(b);
+
+	return r;
+}
+
+int
+sshkey_private_serialize(struct sshkey *key, struct sshbuf *b)
+{
+	return sshkey_private_serialize_opt(key, b,
+	    SSHKEY_SERIALIZE_DEFAULT);
+}
+
+/* Shared deserialization of FIDO private key components */
+int
+sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k)
+{
+	int r;
+
+	if ((k->sk_key_handle = sshbuf_new()) == NULL ||
+	    (k->sk_reserved = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((r = sshbuf_get_cstring(buf, &k->sk_application, NULL)) != 0 ||
+	    (r = sshbuf_get_u8(buf, &k->sk_flags)) != 0 ||
+	    (r = sshbuf_get_stringb(buf, k->sk_key_handle)) != 0 ||
+	    (r = sshbuf_get_stringb(buf, k->sk_reserved)) != 0)
+		return r;
+
+	return 0;
+}
+
+int
+sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
+{
+	const struct sshkey_impl *impl;
+	char *tname = NULL;
+	char *expect_sk_application = NULL;
+	u_char *expect_ed25519_pk = NULL;
+	struct sshkey *k = NULL;
+	int type, r = SSH_ERR_INTERNAL_ERROR;
+
+	if (kp != NULL)
+		*kp = NULL;
+	if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0)
+		goto out;
+	type = sshkey_type_from_name(tname);
+	if (sshkey_type_is_cert(type)) {
+		/*
+		 * Certificate key private keys begin with the certificate
+		 * itself. Make sure this matches the type of the enclosing
+		 * private key.
+		 */
+		if ((r = sshkey_froms(buf, &k)) != 0)
+			goto out;
+		if (k->type != type) {
+			r = SSH_ERR_KEY_CERT_MISMATCH;
+			goto out;
+		}
+		/* For ECDSA keys, the group must match too */
+		if (k->type == KEY_ECDSA &&
+		    k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) {
+			r = SSH_ERR_KEY_CERT_MISMATCH;
+			goto out;
+		}
+		/*
+		 * Several fields are redundant between certificate and
+		 * private key body, we require these to match.
+		 */
+		expect_sk_application = k->sk_application;
+		expect_ed25519_pk = k->ed25519_pk;
+		k->sk_application = NULL;
+		k->ed25519_pk = NULL;
+		/* XXX xmss too or refactor */
+	} else {
+		if ((k = sshkey_new(type)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+	}
+	if ((impl = sshkey_impl_from_type(type)) == NULL) {
+		r = SSH_ERR_INTERNAL_ERROR;
+		goto out;
+	}
+	if ((r = impl->funcs->deserialize_private(tname, buf, k)) != 0)
+		goto out;
+
+	/* XXX xmss too or refactor */
+	if ((expect_sk_application != NULL && (k->sk_application == NULL ||
+	    strcmp(expect_sk_application, k->sk_application) != 0)) ||
+	    (expect_ed25519_pk != NULL && (k->ed25519_pk == NULL ||
+	    memcmp(expect_ed25519_pk, k->ed25519_pk, ED25519_PK_SZ) != 0))) {
+		r = SSH_ERR_KEY_CERT_MISMATCH;
+		goto out;
+	}
+	/* success */
+	r = 0;
+	if (kp != NULL) {
+		*kp = k;
+		k = NULL;
+	}
+ out:
+	free(tname);
+	sshkey_free(k);
+	free(expect_sk_application);
+	free(expect_ed25519_pk);
+	return r;
+}
+
+#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
+int
+sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
+{
+	EC_POINT *nq = NULL;
+	BIGNUM *order = NULL, *x = NULL, *y = NULL, *tmp = NULL;
+	int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
+
+	/*
+	 * NB. This assumes OpenSSL has already verified that the public
+	 * point lies on the curve. This is done by EC_POINT_oct2point()
+	 * implicitly calling EC_POINT_is_on_curve(). If this code is ever
+	 * reachable with public points not unmarshalled using
+	 * EC_POINT_oct2point then the caller will need to explicitly check.
+	 */
+
+	/*
+	 * We shouldn't ever hit this case because bignum_get_ecpoint()
+	 * refuses to load GF2m points.
+	 */
+	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
+	    NID_X9_62_prime_field)
+		goto out;
+
+	/* Q != infinity */
+	if (EC_POINT_is_at_infinity(group, public))
+		goto out;
+
+	if ((x = BN_new()) == NULL ||
+	    (y = BN_new()) == NULL ||
+	    (order = BN_new()) == NULL ||
+	    (tmp = BN_new()) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+
+	/* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
+	if (EC_GROUP_get_order(group, order, NULL) != 1 ||
+	    EC_POINT_get_affine_coordinates_GFp(group, public,
+	    x, y, NULL) != 1) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (BN_num_bits(x) <= BN_num_bits(order) / 2 ||
+	    BN_num_bits(y) <= BN_num_bits(order) / 2)
+		goto out;
+
+	/* nQ == infinity (n == order of subgroup) */
+	if ((nq = EC_POINT_new(group)) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (EC_POINT_mul(group, nq, NULL, public, order, NULL) != 1) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (EC_POINT_is_at_infinity(group, nq) != 1)
+		goto out;
+
+	/* x < order - 1, y < order - 1 */
+	if (!BN_sub(tmp, order, BN_value_one())) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0)
+		goto out;
+	ret = 0;
+ out:
+	BN_clear_free(x);
+	BN_clear_free(y);
+	BN_clear_free(order);
+	BN_clear_free(tmp);
+	EC_POINT_free(nq);
+	return ret;
+}
+
+int
+sshkey_ec_validate_private(const EC_KEY *key)
+{
+	BIGNUM *order = NULL, *tmp = NULL;
+	int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
+
+	if ((order = BN_new()) == NULL || (tmp = BN_new()) == NULL) {
+		ret = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+
+	/* log2(private) > log2(order)/2 */
+	if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, NULL) != 1) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (BN_num_bits(EC_KEY_get0_private_key(key)) <=
+	    BN_num_bits(order) / 2)
+		goto out;
+
+	/* private < order - 1 */
+	if (!BN_sub(tmp, order, BN_value_one())) {
+		ret = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (BN_cmp(EC_KEY_get0_private_key(key), tmp) >= 0)
+		goto out;
+	ret = 0;
+ out:
+	BN_clear_free(order);
+	BN_clear_free(tmp);
+	return ret;
+}
+
+void
+sshkey_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
+{
+	BIGNUM *x = NULL, *y = NULL;
+
+	if (point == NULL) {
+		fputs("point=(NULL)\n", stderr);
+		return;
+	}
+	if ((x = BN_new()) == NULL || (y = BN_new()) == NULL) {
+		fprintf(stderr, "%s: BN_new failed\n", __func__);
+		goto out;
+	}
+	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
+	    NID_X9_62_prime_field) {
+		fprintf(stderr, "%s: group is not a prime field\n", __func__);
+		goto out;
+	}
+	if (EC_POINT_get_affine_coordinates_GFp(group, point,
+	    x, y, NULL) != 1) {
+		fprintf(stderr, "%s: EC_POINT_get_affine_coordinates_GFp\n",
+		    __func__);
+		goto out;
+	}
+	fputs("x=", stderr);
+	BN_print_fp(stderr, x);
+	fputs("\ny=", stderr);
+	BN_print_fp(stderr, y);
+	fputs("\n", stderr);
+ out:
+	BN_clear_free(x);
+	BN_clear_free(y);
+}
+
+void
+sshkey_dump_ec_key(const EC_KEY *key)
+{
+	const BIGNUM *exponent;
+
+	sshkey_dump_ec_point(EC_KEY_get0_group(key),
+	    EC_KEY_get0_public_key(key));
+	fputs("exponent=", stderr);
+	if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
+		fputs("(NULL)", stderr);
+	else
+		BN_print_fp(stderr, EC_KEY_get0_private_key(key));
+	fputs("\n", stderr);
+}
+#endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
+
+static int
+sshkey_private_to_blob2(struct sshkey *prv, struct sshbuf *blob,
+    const char *passphrase, const char *comment, const char *ciphername,
+    int rounds)
+{
+	u_char *cp, *key = NULL, *pubkeyblob = NULL;
+	u_char salt[SALT_LEN];
+	size_t i, pubkeylen, keylen, ivlen, blocksize, authlen;
+	u_int check;
+	int r = SSH_ERR_INTERNAL_ERROR;
+	struct sshcipher_ctx *ciphercontext = NULL;
+	const struct sshcipher *cipher;
+	const char *kdfname = KDFNAME;
+	struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL;
+
+	if (rounds <= 0)
+		rounds = DEFAULT_ROUNDS;
+	if (passphrase == NULL || !strlen(passphrase)) {
+		ciphername = "none";
+		kdfname = "none";
+	} else if (ciphername == NULL)
+		ciphername = DEFAULT_CIPHERNAME;
+	if ((cipher = cipher_by_name(ciphername)) == NULL) {
+		r = SSH_ERR_INVALID_ARGUMENT;
+		goto out;
+	}
+
+	if ((kdf = sshbuf_new()) == NULL ||
+	    (encoded = sshbuf_new()) == NULL ||
+	    (encrypted = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	blocksize = cipher_blocksize(cipher);
+	keylen = cipher_keylen(cipher);
+	ivlen = cipher_ivlen(cipher);
+	authlen = cipher_authlen(cipher);
+	if ((key = calloc(1, keylen + ivlen)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (strcmp(kdfname, "bcrypt") == 0) {
+		arc4random_buf(salt, SALT_LEN);
+		if (bcrypt_pbkdf(passphrase, strlen(passphrase),
+		    salt, SALT_LEN, key, keylen + ivlen, rounds) < 0) {
+			r = SSH_ERR_INVALID_ARGUMENT;
+			goto out;
+		}
+		if ((r = sshbuf_put_string(kdf, salt, SALT_LEN)) != 0 ||
+		    (r = sshbuf_put_u32(kdf, rounds)) != 0)
+			goto out;
+	} else if (strcmp(kdfname, "none") != 0) {
+		/* Unsupported KDF type */
+		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
+		goto out;
+	}
+	if ((r = cipher_init(&ciphercontext, cipher, key, keylen,
+	    key + keylen, ivlen, 1)) != 0)
+		goto out;
+
+	if ((r = sshbuf_put(encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC))) != 0 ||
+	    (r = sshbuf_put_cstring(encoded, ciphername)) != 0 ||
+	    (r = sshbuf_put_cstring(encoded, kdfname)) != 0 ||
+	    (r = sshbuf_put_stringb(encoded, kdf)) != 0 ||
+	    (r = sshbuf_put_u32(encoded, 1)) != 0 ||	/* number of keys */
+	    (r = sshkey_to_blob(prv, &pubkeyblob, &pubkeylen)) != 0 ||
+	    (r = sshbuf_put_string(encoded, pubkeyblob, pubkeylen)) != 0)
+		goto out;
+
+	/* set up the buffer that will be encrypted */
+
+	/* Random check bytes */
+	check = arc4random();
+	if ((r = sshbuf_put_u32(encrypted, check)) != 0 ||
+	    (r = sshbuf_put_u32(encrypted, check)) != 0)
+		goto out;
+
+	/* append private key and comment*/
+	if ((r = sshkey_private_serialize_opt(prv, encrypted,
+	    SSHKEY_SERIALIZE_FULL)) != 0 ||
+	    (r = sshbuf_put_cstring(encrypted, comment)) != 0)
+		goto out;
+
+	/* padding */
+	i = 0;
+	while (sshbuf_len(encrypted) % blocksize) {
+		if ((r = sshbuf_put_u8(encrypted, ++i & 0xff)) != 0)
+			goto out;
+	}
+
+	/* length in destination buffer */
+	if ((r = sshbuf_put_u32(encoded, sshbuf_len(encrypted))) != 0)
+		goto out;
+
+	/* encrypt */
+	if ((r = sshbuf_reserve(encoded,
+	    sshbuf_len(encrypted) + authlen, &cp)) != 0)
+		goto out;
+	if ((r = cipher_crypt(ciphercontext, 0, cp,
+	    sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0)
+		goto out;
+
+	sshbuf_reset(blob);
+
+	/* assemble uuencoded key */
+	if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0 ||
+	    (r = sshbuf_dtob64(encoded, blob, 1)) != 0 ||
+	    (r = sshbuf_put(blob, MARK_END, MARK_END_LEN)) != 0)
+		goto out;
+
+	/* success */
+	r = 0;
+
+ out:
+	sshbuf_free(kdf);
+	sshbuf_free(encoded);
+	sshbuf_free(encrypted);
+	cipher_free(ciphercontext);
+	explicit_bzero(salt, sizeof(salt));
+	if (key != NULL)
+		freezero(key, keylen + ivlen);
+	if (pubkeyblob != NULL)
+		freezero(pubkeyblob, pubkeylen);
+	return r;
+}
+
+static int
+private2_uudecode(struct sshbuf *blob, struct sshbuf **decodedp)
+{
+	const u_char *cp;
+	size_t encoded_len;
+	int r;
+	u_char last;
+	struct sshbuf *encoded = NULL, *decoded = NULL;
+
+	if (blob == NULL || decodedp == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	*decodedp = NULL;
+
+	if ((encoded = sshbuf_new()) == NULL ||
+	    (decoded = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+
+	/* check preamble */
+	cp = sshbuf_ptr(blob);
+	encoded_len = sshbuf_len(blob);
+	if (encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) ||
+	    memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	cp += MARK_BEGIN_LEN;
+	encoded_len -= MARK_BEGIN_LEN;
+
+	/* Look for end marker, removing whitespace as we go */
+	while (encoded_len > 0) {
+		if (*cp != '\n' && *cp != '\r') {
+			if ((r = sshbuf_put_u8(encoded, *cp)) != 0)
+				goto out;
+		}
+		last = *cp;
+		encoded_len--;
+		cp++;
+		if (last == '\n') {
+			if (encoded_len >= MARK_END_LEN &&
+			    memcmp(cp, MARK_END, MARK_END_LEN) == 0) {
+				/* \0 terminate */
+				if ((r = sshbuf_put_u8(encoded, 0)) != 0)
+					goto out;
+				break;
+			}
+		}
+	}
+	if (encoded_len == 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* decode base64 */
+	if ((r = sshbuf_b64tod(decoded, (char *)sshbuf_ptr(encoded))) != 0)
+		goto out;
+
+	/* check magic */
+	if (sshbuf_len(decoded) < sizeof(AUTH_MAGIC) ||
+	    memcmp(sshbuf_ptr(decoded), AUTH_MAGIC, sizeof(AUTH_MAGIC))) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	/* success */
+	*decodedp = decoded;
+	decoded = NULL;
+	r = 0;
+ out:
+	sshbuf_free(encoded);
+	sshbuf_free(decoded);
+	return r;
+}
+
+static int
+private2_decrypt(struct sshbuf *decoded, const char *passphrase,
+    struct sshbuf **decryptedp, struct sshkey **pubkeyp)
+{
+	char *ciphername = NULL, *kdfname = NULL;
+	const struct sshcipher *cipher = NULL;
+	int r = SSH_ERR_INTERNAL_ERROR;
+	size_t keylen = 0, ivlen = 0, authlen = 0, slen = 0;
+	struct sshbuf *kdf = NULL, *decrypted = NULL;
+	struct sshcipher_ctx *ciphercontext = NULL;
+	struct sshkey *pubkey = NULL;
+	u_char *key = NULL, *salt = NULL, *dp;
+	u_int blocksize, rounds, nkeys, encrypted_len, check1, check2;
+
+	if (decoded == NULL || decryptedp == NULL || pubkeyp == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+
+	*decryptedp = NULL;
+	*pubkeyp = NULL;
+
+	if ((decrypted = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+
+	/* parse public portion of key */
+	if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 ||
+	    (r = sshbuf_get_cstring(decoded, &ciphername, NULL)) != 0 ||
+	    (r = sshbuf_get_cstring(decoded, &kdfname, NULL)) != 0 ||
+	    (r = sshbuf_froms(decoded, &kdf)) != 0 ||
+	    (r = sshbuf_get_u32(decoded, &nkeys)) != 0)
+		goto out;
+
+	if (nkeys != 1) {
+		/* XXX only one key supported at present */
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	if ((r = sshkey_froms(decoded, &pubkey)) != 0 ||
+	    (r = sshbuf_get_u32(decoded, &encrypted_len)) != 0)
+		goto out;
+
+	if ((cipher = cipher_by_name(ciphername)) == NULL) {
+		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
+		goto out;
+	}
+	if (strcmp(kdfname, "none") != 0 && strcmp(kdfname, "bcrypt") != 0) {
+		r = SSH_ERR_KEY_UNKNOWN_CIPHER;
+		goto out;
+	}
+	if (strcmp(kdfname, "none") == 0 && strcmp(ciphername, "none") != 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	if ((passphrase == NULL || strlen(passphrase) == 0) &&
+	    strcmp(kdfname, "none") != 0) {
+		/* passphrase required */
+		r = SSH_ERR_KEY_WRONG_PASSPHRASE;
+		goto out;
+	}
+
+	/* check size of encrypted key blob */
+	blocksize = cipher_blocksize(cipher);
+	if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* setup key */
+	keylen = cipher_keylen(cipher);
+	ivlen = cipher_ivlen(cipher);
+	authlen = cipher_authlen(cipher);
+	if ((key = calloc(1, keylen + ivlen)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (strcmp(kdfname, "bcrypt") == 0) {
+		if ((r = sshbuf_get_string(kdf, &salt, &slen)) != 0 ||
+		    (r = sshbuf_get_u32(kdf, &rounds)) != 0)
+			goto out;
+		if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, slen,
+		    key, keylen + ivlen, rounds) < 0) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+	}
+
+	/* check that an appropriate amount of auth data is present */
+	if (sshbuf_len(decoded) < authlen ||
+	    sshbuf_len(decoded) - authlen < encrypted_len) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* decrypt private portion of key */
+	if ((r = sshbuf_reserve(decrypted, encrypted_len, &dp)) != 0 ||
+	    (r = cipher_init(&ciphercontext, cipher, key, keylen,
+	    key + keylen, ivlen, 0)) != 0)
+		goto out;
+	if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded),
+	    encrypted_len, 0, authlen)) != 0) {
+		/* an integrity error here indicates an incorrect passphrase */
+		if (r == SSH_ERR_MAC_INVALID)
+			r = SSH_ERR_KEY_WRONG_PASSPHRASE;
+		goto out;
+	}
+	if ((r = sshbuf_consume(decoded, encrypted_len + authlen)) != 0)
+		goto out;
+	/* there should be no trailing data */
+	if (sshbuf_len(decoded) != 0) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* check check bytes */
+	if ((r = sshbuf_get_u32(decrypted, &check1)) != 0 ||
+	    (r = sshbuf_get_u32(decrypted, &check2)) != 0)
+		goto out;
+	if (check1 != check2) {
+		r = SSH_ERR_KEY_WRONG_PASSPHRASE;
+		goto out;
+	}
+	/* success */
+	*decryptedp = decrypted;
+	decrypted = NULL;
+	*pubkeyp = pubkey;
+	pubkey = NULL;
+	r = 0;
+ out:
+	cipher_free(ciphercontext);
+	free(ciphername);
+	free(kdfname);
+	sshkey_free(pubkey);
+	if (salt != NULL) {
+		explicit_bzero(salt, slen);
+		free(salt);
+	}
+	if (key != NULL) {
+		explicit_bzero(key, keylen + ivlen);
+		free(key);
+	}
+	sshbuf_free(kdf);
+	sshbuf_free(decrypted);
+	return r;
+}
+
+static int
+sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
+    struct sshkey **keyp, char **commentp)
+{
+	char *comment = NULL;
+	int r = SSH_ERR_INTERNAL_ERROR;
+	struct sshbuf *decoded = NULL, *decrypted = NULL;
+	struct sshkey *k = NULL, *pubkey = NULL;
+
+	if (keyp != NULL)
+		*keyp = NULL;
+	if (commentp != NULL)
+		*commentp = NULL;
+
+	/* Undo base64 encoding and decrypt the private section */
+	if ((r = private2_uudecode(blob, &decoded)) != 0 ||
+	    (r = private2_decrypt(decoded, passphrase,
+	    &decrypted, &pubkey)) != 0)
+		goto out;
+
+	if (type != KEY_UNSPEC &&
+	    sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) {
+		r = SSH_ERR_KEY_TYPE_MISMATCH;
+		goto out;
+	}
+
+	/* Load the private key and comment */
+	if ((r = sshkey_private_deserialize(decrypted, &k)) != 0 ||
+	    (r = sshbuf_get_cstring(decrypted, &comment, NULL)) != 0)
+		goto out;
+
+	/* Check deterministic padding after private section */
+	if ((r = private2_check_padding(decrypted)) != 0)
+		goto out;
+
+	/* Check that the public key in the envelope matches the private key */
+	if (!sshkey_equal(pubkey, k)) {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* success */
+	r = 0;
+	if (keyp != NULL) {
+		*keyp = k;
+		k = NULL;
+	}
+	if (commentp != NULL) {
+		*commentp = comment;
+		comment = NULL;
+	}
+ out:
+	free(comment);
+	sshbuf_free(decoded);
+	sshbuf_free(decrypted);
+	sshkey_free(k);
+	sshkey_free(pubkey);
+	return r;
+}
+
+static int
+sshkey_parse_private2_pubkey(struct sshbuf *blob, int type,
+    struct sshkey **keyp)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+	struct sshbuf *decoded = NULL;
+	struct sshkey *pubkey = NULL;
+	u_int nkeys = 0;
+
+	if (keyp != NULL)
+		*keyp = NULL;
+
+	if ((r = private2_uudecode(blob, &decoded)) != 0)
+		goto out;
+	/* parse public key from unencrypted envelope */
+	if ((r = sshbuf_consume(decoded, sizeof(AUTH_MAGIC))) != 0 ||
+	    (r = sshbuf_skip_string(decoded)) != 0 || /* cipher */
+	    (r = sshbuf_skip_string(decoded)) != 0 || /* KDF alg */
+	    (r = sshbuf_skip_string(decoded)) != 0 || /* KDF hint */
+	    (r = sshbuf_get_u32(decoded, &nkeys)) != 0)
+		goto out;
+
+	if (nkeys != 1) {
+		/* XXX only one key supported at present */
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+
+	/* Parse the public key */
+	if ((r = sshkey_froms(decoded, &pubkey)) != 0)
+		goto out;
+
+	if (type != KEY_UNSPEC &&
+	    sshkey_type_plain(type) != sshkey_type_plain(pubkey->type)) {
+		r = SSH_ERR_KEY_TYPE_MISMATCH;
+		goto out;
+	}
+
+	/* success */
+	r = 0;
+	if (keyp != NULL) {
+		*keyp = pubkey;
+		pubkey = NULL;
+	}
+ out:
+	sshbuf_free(decoded);
+	sshkey_free(pubkey);
+	return r;
+}
+
+#ifdef WITH_OPENSSL
+/* convert SSH v2 key to PEM or PKCS#8 format */
+static int
+sshkey_private_to_blob_pem_pkcs8(struct sshkey *key, struct sshbuf *buf,
+    int format, const char *_passphrase, const char *comment)
+{
+	int was_shielded = sshkey_is_shielded(key);
+	int success, r;
+	int blen, len = strlen(_passphrase);
+	u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL;
+	const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL;
+	char *bptr;
+	BIO *bio = NULL;
+	struct sshbuf *blob;
+	EVP_PKEY *pkey = NULL;
+
+	if (len > 0 && len <= 4)
+		return SSH_ERR_PASSPHRASE_TOO_SHORT;
+	if ((blob = sshbuf_new()) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	if ((bio = BIO_new(BIO_s_mem())) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if (format == SSHKEY_PRIVATE_PKCS8 && (pkey = EVP_PKEY_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_unshield_private(key)) != 0)
+		goto out;
+
+	switch (key->type) {
+	case KEY_DSA:
+		if (format == SSHKEY_PRIVATE_PEM) {
+			success = PEM_write_bio_DSAPrivateKey(bio, key->dsa,
+			    cipher, passphrase, len, NULL, NULL);
+		} else {
+			success = EVP_PKEY_set1_DSA(pkey, key->dsa);
+		}
+		break;
+#ifdef OPENSSL_HAS_ECC
+	case KEY_ECDSA:
+		if (format == SSHKEY_PRIVATE_PEM) {
+			success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa,
+			    cipher, passphrase, len, NULL, NULL);
+		} else {
+			success = EVP_PKEY_set1_EC_KEY(pkey, key->ecdsa);
+		}
+		break;
+#endif
+	case KEY_RSA:
+		if (format == SSHKEY_PRIVATE_PEM) {
+			success = PEM_write_bio_RSAPrivateKey(bio, key->rsa,
+			    cipher, passphrase, len, NULL, NULL);
+		} else {
+			success = EVP_PKEY_set1_RSA(pkey, key->rsa);
+		}
+		break;
+	default:
+		success = 0;
+		break;
+	}
+	if (success == 0) {
+		r = SSH_ERR_LIBCRYPTO_ERROR;
+		goto out;
+	}
+	if (format == SSHKEY_PRIVATE_PKCS8) {
+		if ((success = PEM_write_bio_PrivateKey(bio, pkey, cipher,
+		    passphrase, len, NULL, NULL)) == 0) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+	}
+	if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) {
+		r = SSH_ERR_INTERNAL_ERROR;
+		goto out;
+	}
+	if ((r = sshbuf_put(blob, bptr, blen)) != 0)
+		goto out;
+	r = 0;
+ out:
+	if (was_shielded)
+		r = sshkey_shield_private(key);
+	if (r == 0)
+		r = sshbuf_putb(buf, blob);
+
+	EVP_PKEY_free(pkey);
+	sshbuf_free(blob);
+	BIO_free(bio);
+	return r;
+}
+#endif /* WITH_OPENSSL */
+
+/* Serialise "key" to buffer "blob" */
+int
+sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
+    const char *passphrase, const char *comment,
+    int format, const char *openssh_format_cipher, int openssh_format_rounds)
+{
+	switch (key->type) {
+#ifdef WITH_OPENSSL
+	case KEY_DSA:
+	case KEY_ECDSA:
+	case KEY_RSA:
+		break; /* see below */
+#endif /* WITH_OPENSSL */
+	case KEY_ED25519:
+	case KEY_ED25519_SK:
+#ifdef WITH_XMSS
+	case KEY_XMSS:
+#endif /* WITH_XMSS */
+#ifdef WITH_OPENSSL
+	case KEY_ECDSA_SK:
+#endif /* WITH_OPENSSL */
+		return sshkey_private_to_blob2(key, blob, passphrase,
+		    comment, openssh_format_cipher, openssh_format_rounds);
+	default:
+		return SSH_ERR_KEY_TYPE_UNKNOWN;
+	}
+
+#ifdef WITH_OPENSSL
+	switch (format) {
+	case SSHKEY_PRIVATE_OPENSSH:
+		return sshkey_private_to_blob2(key, blob, passphrase,
+		    comment, openssh_format_cipher, openssh_format_rounds);
+	case SSHKEY_PRIVATE_PEM:
+	case SSHKEY_PRIVATE_PKCS8:
+		return sshkey_private_to_blob_pem_pkcs8(key, blob,
+		    format, passphrase, comment);
+	default:
+		return SSH_ERR_INVALID_ARGUMENT;
+	}
+#endif /* WITH_OPENSSL */
+}
+
+#ifdef WITH_OPENSSL
+static int
+translate_libcrypto_error(unsigned long pem_err)
+{
+	int pem_reason = ERR_GET_REASON(pem_err);
+
+	switch (ERR_GET_LIB(pem_err)) {
+	case ERR_LIB_PEM:
+		switch (pem_reason) {
+		case PEM_R_BAD_PASSWORD_READ:
+#ifdef PEM_R_PROBLEMS_GETTING_PASSWORD
+		case PEM_R_PROBLEMS_GETTING_PASSWORD:
+#endif
+#ifdef PEM_R_BAD_DECRYPT
+		case PEM_R_BAD_DECRYPT:
+#endif
+			return SSH_ERR_KEY_WRONG_PASSPHRASE;
+		default:
+			return SSH_ERR_INVALID_FORMAT;
+		}
+	case ERR_LIB_EVP:
+		switch (pem_reason) {
+#ifdef EVP_R_BAD_DECRYPT
+		case EVP_R_BAD_DECRYPT:
+			return SSH_ERR_KEY_WRONG_PASSPHRASE;
+#endif
+#ifdef EVP_R_BN_DECODE_ERROR
+		case EVP_R_BN_DECODE_ERROR:
+#endif
+		case EVP_R_DECODE_ERROR:
+#ifdef EVP_R_PRIVATE_KEY_DECODE_ERROR
+		case EVP_R_PRIVATE_KEY_DECODE_ERROR:
+#endif
+			return SSH_ERR_INVALID_FORMAT;
+		default:
+			return SSH_ERR_LIBCRYPTO_ERROR;
+		}
+	case ERR_LIB_ASN1:
+		return SSH_ERR_INVALID_FORMAT;
+	}
+	return SSH_ERR_LIBCRYPTO_ERROR;
+}
+
+static void
+clear_libcrypto_errors(void)
+{
+	while (ERR_get_error() != 0)
+		;
+}
+
+/*
+ * Translate OpenSSL error codes to determine whether
+ * passphrase is required/incorrect.
+ */
+static int
+convert_libcrypto_error(void)
+{
+	/*
+	 * Some password errors are reported at the beginning
+	 * of the error queue.
+	 */
+	if (translate_libcrypto_error(ERR_peek_error()) ==
+	    SSH_ERR_KEY_WRONG_PASSPHRASE)
+		return SSH_ERR_KEY_WRONG_PASSPHRASE;
+	return translate_libcrypto_error(ERR_peek_last_error());
+}
+
+static int
+pem_passphrase_cb(char *buf, int size, int rwflag, void *u)
+{
+	char *p = (char *)u;
+	size_t len;
+
+	if (p == NULL || (len = strlen(p)) == 0)
+		return -1;
+	if (size < 0 || len > (size_t)size)
+		return -1;
+	memcpy(buf, p, len);
+	return (int)len;
+}
+
+static int
+sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type,
+    const char *passphrase, struct sshkey **keyp)
+{
+	EVP_PKEY *pk = NULL;
+	struct sshkey *prv = NULL;
+	BIO *bio = NULL;
+	int r;
+
+	if (keyp != NULL)
+		*keyp = NULL;
+
+	if ((bio = BIO_new(BIO_s_mem())) == NULL || sshbuf_len(blob) > INT_MAX)
+		return SSH_ERR_ALLOC_FAIL;
+	if (BIO_write(bio, sshbuf_ptr(blob), sshbuf_len(blob)) !=
+	    (int)sshbuf_len(blob)) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+
+	clear_libcrypto_errors();
+	if ((pk = PEM_read_bio_PrivateKey(bio, NULL, pem_passphrase_cb,
+	    (char *)passphrase)) == NULL) {
+		/*
+		 * libcrypto may return various ASN.1 errors when attempting
+		 * to parse a key with an incorrect passphrase.
+		 * Treat all format errors as "incorrect passphrase" if a
+		 * passphrase was supplied.
+		 */
+		if (passphrase != NULL && *passphrase != '\0')
+			r = SSH_ERR_KEY_WRONG_PASSPHRASE;
+		else
+			r = convert_libcrypto_error();
+		goto out;
+	}
+	if (EVP_PKEY_base_id(pk) == EVP_PKEY_RSA &&
+	    (type == KEY_UNSPEC || type == KEY_RSA)) {
+		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		prv->rsa = EVP_PKEY_get1_RSA(pk);
+		prv->type = KEY_RSA;
+#ifdef DEBUG_PK
+		RSA_print_fp(stderr, prv->rsa, 8);
+#endif
+		if (RSA_blinding_on(prv->rsa, NULL) != 1) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+		if ((r = sshkey_check_rsa_length(prv, 0)) != 0)
+			goto out;
+	} else if (EVP_PKEY_base_id(pk) == EVP_PKEY_DSA &&
+	    (type == KEY_UNSPEC || type == KEY_DSA)) {
+		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		prv->dsa = EVP_PKEY_get1_DSA(pk);
+		prv->type = KEY_DSA;
+#ifdef DEBUG_PK
+		DSA_print_fp(stderr, prv->dsa, 8);
+#endif
+#ifdef OPENSSL_HAS_ECC
+	} else if (EVP_PKEY_base_id(pk) == EVP_PKEY_EC &&
+	    (type == KEY_UNSPEC || type == KEY_ECDSA)) {
+		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
+		prv->type = KEY_ECDSA;
+		prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa);
+		if (prv->ecdsa_nid == -1 ||
+		    sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
+		    sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
+		    EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
+		    sshkey_ec_validate_private(prv->ecdsa) != 0) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+# ifdef DEBUG_PK
+		if (prv != NULL && prv->ecdsa != NULL)
+			sshkey_dump_ec_key(prv->ecdsa);
+# endif
+#endif /* OPENSSL_HAS_ECC */
+#ifdef OPENSSL_HAS_ED25519
+	} else if (EVP_PKEY_base_id(pk) == EVP_PKEY_ED25519 &&
+	    (type == KEY_UNSPEC || type == KEY_ED25519)) {
+		size_t len;
+
+		if ((prv = sshkey_new(KEY_UNSPEC)) == NULL ||
+		    (prv->ed25519_sk = calloc(1, ED25519_SK_SZ)) == NULL ||
+		    (prv->ed25519_pk = calloc(1, ED25519_PK_SZ)) == NULL) {
+			r = SSH_ERR_ALLOC_FAIL;
+			goto out;
+		}
+		prv->type = KEY_ED25519;
+		len = ED25519_PK_SZ;
+		if (!EVP_PKEY_get_raw_public_key(pk, prv->ed25519_pk, &len)) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+		if (len != ED25519_PK_SZ) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		len = ED25519_SK_SZ - ED25519_PK_SZ;
+		if (!EVP_PKEY_get_raw_private_key(pk, prv->ed25519_sk, &len)) {
+			r = SSH_ERR_LIBCRYPTO_ERROR;
+			goto out;
+		}
+		if (len != ED25519_SK_SZ - ED25519_PK_SZ) {
+			r = SSH_ERR_INVALID_FORMAT;
+			goto out;
+		}
+		/* Append the public key to our private key */
+		memcpy(prv->ed25519_sk + (ED25519_SK_SZ - ED25519_PK_SZ),
+		    prv->ed25519_pk, ED25519_PK_SZ);
+# ifdef DEBUG_PK
+		sshbuf_dump_data(prv->ed25519_sk, ED25519_SK_SZ, stderr);
+# endif
+#endif /* OPENSSL_HAS_ED25519 */
+	} else {
+		r = SSH_ERR_INVALID_FORMAT;
+		goto out;
+	}
+	r = 0;
+	if (keyp != NULL) {
+		*keyp = prv;
+		prv = NULL;
+	}
+ out:
+	BIO_free(bio);
+	EVP_PKEY_free(pk);
+	sshkey_free(prv);
+	return r;
+}
+#endif /* WITH_OPENSSL */
+
+int
+sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
+    const char *passphrase, struct sshkey **keyp, char **commentp)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	if (keyp != NULL)
+		*keyp = NULL;
+	if (commentp != NULL)
+		*commentp = NULL;
+
+	switch (type) {
+	case KEY_XMSS:
+		/* No fallback for new-format-only keys */
+		return sshkey_parse_private2(blob, type, passphrase,
+		    keyp, commentp);
+	default:
+		r = sshkey_parse_private2(blob, type, passphrase, keyp,
+		    commentp);
+		/* Only fallback to PEM parser if a format error occurred. */
+		if (r != SSH_ERR_INVALID_FORMAT)
+			return r;
+#ifdef WITH_OPENSSL
+		return sshkey_parse_private_pem_fileblob(blob, type,
+		    passphrase, keyp);
+#else
+		return SSH_ERR_INVALID_FORMAT;
+#endif /* WITH_OPENSSL */
+	}
+}
+
+int
+sshkey_parse_private_fileblob(struct sshbuf *buffer, const char *passphrase,
+    struct sshkey **keyp, char **commentp)
+{
+	if (keyp != NULL)
+		*keyp = NULL;
+	if (commentp != NULL)
+		*commentp = NULL;
+
+	return sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC,
+	    passphrase, keyp, commentp);
+}
+
+void
+sshkey_sig_details_free(struct sshkey_sig_details *details)
+{
+	freezero(details, sizeof(*details));
+}
+
+int
+sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, int type,
+    struct sshkey **pubkeyp)
+{
+	int r = SSH_ERR_INTERNAL_ERROR;
+
+	if (pubkeyp != NULL)
+		*pubkeyp = NULL;
+	/* only new-format private keys bundle a public key inside */
+	if ((r = sshkey_parse_private2_pubkey(blob, type, pubkeyp)) != 0)
+		return r;
+	return 0;
+}
+
+#ifdef WITH_XMSS
+/*
+ * serialize the key with the current state and forward the state
+ * maxsign times.
+ */
+int
+sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b,
+    u_int32_t maxsign, int printerror)
+{
+	int r, rupdate;
+
+	if (maxsign == 0 ||
+	    sshkey_type_plain(k->type) != KEY_XMSS)
+		return sshkey_private_serialize_opt(k, b,
+		    SSHKEY_SERIALIZE_DEFAULT);
+	if ((r = sshkey_xmss_get_state(k, printerror)) != 0 ||
+	    (r = sshkey_private_serialize_opt(k, b,
+	    SSHKEY_SERIALIZE_STATE)) != 0 ||
+	    (r = sshkey_xmss_forward_state(k, maxsign)) != 0)
+		goto out;
+	r = 0;
+out:
+	if ((rupdate = sshkey_xmss_update_state(k, printerror)) != 0) {
+		if (r == 0)
+			r = rupdate;
+	}
+	return r;
+}
+
+u_int32_t
+sshkey_signatures_left(const struct sshkey *k)
+{
+	if (sshkey_type_plain(k->type) == KEY_XMSS)
+		return sshkey_xmss_signatures_left(k);
+	return 0;
+}
+
+int
+sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
+{
+	if (sshkey_type_plain(k->type) != KEY_XMSS)
+		return SSH_ERR_INVALID_ARGUMENT;
+	return sshkey_xmss_enable_maxsign(k, maxsign);
+}
+
+int
+sshkey_set_filename(struct sshkey *k, const char *filename)
+{
+	if (k == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if (sshkey_type_plain(k->type) != KEY_XMSS)
+		return 0;
+	if (filename == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	if ((k->xmss_filename = strdup(filename)) == NULL)
+		return SSH_ERR_ALLOC_FAIL;
+	return 0;
+}
+#else
+int
+sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b,
+    u_int32_t maxsign, int printerror)
+{
+	return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT);
+}
+
+u_int32_t
+sshkey_signatures_left(const struct sshkey *k)
+{
+	return 0;
+}
+
+int
+sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign)
+{
+	return SSH_ERR_INVALID_ARGUMENT;
+}
+
+int
+sshkey_set_filename(struct sshkey *k, const char *filename)
+{
+	if (k == NULL)
+		return SSH_ERR_INVALID_ARGUMENT;
+	return 0;
+}
+#endif /* WITH_XMSS */