/* $OpenBSD: sshkey.c,v 1.161 2026/02/06 22:59:18 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 <sys/types.h>
#include <sys/mman.h>
#include <netinet/in.h>

#ifdef WITH_OPENSSL
#include <openssl/bn.h>
#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>
#include <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"
#include "ssh-pkcs11.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

/*
 * 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

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
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;
extern const struct sshkey_impl sshkey_ecdsa_sk_webauthn_cert_impl;
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;
extern const struct sshkey_impl sshkey_ecdsa_nistp521_impl;
extern const struct sshkey_impl sshkey_ecdsa_nistp521_cert_impl;
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;
#endif /* WITH_OPENSSL */

const struct sshkey_impl * const keyimpls[] = {
        &sshkey_ed25519_impl,
        &sshkey_ed25519_cert_impl,
        &sshkey_ed25519_sk_impl,
        &sshkey_ed25519_sk_cert_impl,
#ifdef WITH_OPENSSL
        &sshkey_ecdsa_nistp256_impl,
        &sshkey_ecdsa_nistp256_cert_impl,
        &sshkey_ecdsa_nistp384_impl,
        &sshkey_ecdsa_nistp384_cert_impl,
        &sshkey_ecdsa_nistp521_impl,
        &sshkey_ecdsa_nistp521_cert_impl,
        &sshkey_ecdsa_sk_impl,
        &sshkey_ecdsa_sk_cert_impl,
        &sshkey_ecdsa_sk_webauthn_impl,
        &sshkey_ecdsa_sk_webauthn_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 */
        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);
}

static int
type_from_name(const char *name, int allow_short)
{
        int i;
        const struct sshkey_impl *impl;

        for (i = 0; keyimpls[i] != NULL; i++) {
                impl = keyimpls[i];
                if (impl->name != NULL && strcmp(name, impl->name) == 0)
                        return impl->type;
                /* Only allow shortname matches for plain key types */
                if (allow_short && !impl->cert && impl->shortname != NULL &&
                    strcasecmp(impl->shortname, name) == 0)
                        return impl->type;
        }
        return KEY_UNSPEC;
}

int
sshkey_type_from_name(const char *name)
{
        return type_from_name(name, 0);
}

int
sshkey_type_from_shortname(const char *name)
{
        return type_from_name(name, 1);
}

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 if (ktype == KEY_ECDSA_SK) {
                return match_pattern_list("sk-ecdsa-sha2-nistp256@openssh.com",
                    sigalgs, 0) == 1 || match_pattern_list(
                    "webauthn-sk-ecdsa-sha2-nistp256@openssh.com",
                    sigalgs, 0) == 1;
        } else if (ktype == KEY_ECDSA_SK_CERT) {
                return match_pattern_list(
                    "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com",
                    sigalgs, 0) == 1 || match_pattern_list(
                    "webauthn-sk-ecdsa-sha2-nistp256-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 *ret = NULL;
        size_t i;
        const struct sshkey_impl *impl;
        char sep_str[2] = {sep, '\0'};

        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;
                xextendf(&ret, sep_str, "%s", impl->name);
        }
        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_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;
        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_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;
        default:
                return -1;
        }
}

#ifdef WITH_OPENSSL
static const EVP_MD *
ssh_digest_to_md(int hash_alg)
{
        switch (hash_alg) {
        case SSH_DIGEST_SHA1:
                return EVP_sha1();
        case SSH_DIGEST_SHA256:
                return EVP_sha256();
        case SSH_DIGEST_SHA384:
                return EVP_sha384();
        case SSH_DIGEST_SHA512:
                return EVP_sha512();
        }
        return NULL;
}

int
sshkey_pkey_digest_sign(EVP_PKEY *pkey, int hash_alg, u_char **sigp,
    size_t *lenp, const u_char *data, size_t datalen)
{
        EVP_MD_CTX *ctx = NULL;
        u_char *sig = NULL;
        int ret;
        size_t slen;
        const EVP_MD *evpmd;

        *sigp = NULL;
        *lenp = 0;

        slen = EVP_PKEY_size(pkey);
        if (slen <= 0 || slen > SSHBUF_MAX_BIGNUM ||
           (evpmd = ssh_digest_to_md(hash_alg)) == NULL)
                return SSH_ERR_INVALID_ARGUMENT;

        if ((sig = malloc(slen)) == NULL)
                return SSH_ERR_ALLOC_FAIL;

        if ((ctx = EVP_MD_CTX_new()) == NULL) {
                ret = SSH_ERR_ALLOC_FAIL;
                goto out;
        }
        if (EVP_DigestSignInit(ctx, NULL, evpmd, NULL, pkey) != 1 ||
            EVP_DigestSign(ctx, sig, &slen, data, datalen) != 1) {
                ret = SSH_ERR_LIBCRYPTO_ERROR;
                goto out;
        }

        *sigp = sig;
        *lenp = slen;
        /* Now owned by the caller */
        sig = NULL;
        ret = 0;

 out:
        EVP_MD_CTX_free(ctx);
        free(sig);
        return ret;
}

int
sshkey_pkey_digest_verify(EVP_PKEY *pkey, int hash_alg, const u_char *data,
    size_t datalen, u_char *sigbuf, size_t siglen)
{
        EVP_MD_CTX *ctx = NULL;
        int ret = SSH_ERR_INTERNAL_ERROR;
        const EVP_MD *evpmd;

        if ((evpmd = ssh_digest_to_md(hash_alg)) == NULL)
                return SSH_ERR_INVALID_ARGUMENT;
        if ((ctx = EVP_MD_CTX_new()) == NULL)
                return SSH_ERR_ALLOC_FAIL;
        if (EVP_DigestVerifyInit(ctx, NULL, evpmd, NULL, pkey) != 1) {
                ret = SSH_ERR_LIBCRYPTO_ERROR;
                goto out;
        }
        switch (EVP_DigestVerify(ctx, sigbuf, siglen, data, datalen)) {
        case 1:
                ret = 0;
                break;
        case 0:
                ret = SSH_ERR_SIGNATURE_INVALID;
                break;
        default:
                ret = SSH_ERR_LIBCRYPTO_ERROR;
                break;
        }

 out:
        EVP_MD_CTX_free(ctx);
        return ret;
}

/* 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;
        else if (strcmp(name, "nistp521") == 0)
                return NID_secp521r1;
        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;
        case NID_secp521r1:
                return 521;
        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;
        case 521:
                return NID_secp521r1;
        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";
        case NID_secp521r1:
                return "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 int
sshkey_prekey_alloc(u_char **prekeyp, size_t len)
{
        u_char *prekey;

        *prekeyp = NULL;
        if ((prekey = mmap(NULL, len, PROT_READ|PROT_WRITE,
            MAP_ANON|MAP_PRIVATE|MAP_CONCEAL, -1, 0)) == MAP_FAILED)
                return SSH_ERR_SYSTEM_ERROR;
        *prekeyp = prekey;
        return 0;
}

static void
sshkey_prekey_free(void *prekey, size_t len)
{
        if (prekey == NULL)
                return;
        munmap(prekey, len);
}

static void
sshkey_free_contents(struct sshkey *k)
{
        const struct sshkey_impl *impl;

        if (k == NULL)
                return;
        if ((k->flags & SSHKEY_FLAG_EXT) != 0)
                pkcs11_key_free(k);
        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);
        sshkey_prekey_free(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);
}

static int
sshkey_puts_opts_internal(const struct sshkey *key, struct sshbuf *b,
    enum sshkey_serialize_rep opts, int force_plain)
{
        struct sshbuf *tmp;
        int r;

        if ((tmp = sshbuf_new()) == NULL)
                return SSH_ERR_ALLOC_FAIL;
        r = to_blob_buf(key, tmp, force_plain, 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_internal(key, b, SSHKEY_SERIALIZE_DEFAULT, 0);
}

int
sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b)
{
        return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT);
}

int
sshkey_puts_plain(const struct sshkey *key, struct sshbuf *b)
{
        return sshkey_puts_opts_internal(key, b, SSHKEY_SERIALIZE_DEFAULT, 1);
}

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
        int nbits;

        if (k == NULL || k->pkey == NULL ||
            (k->type != KEY_RSA && k->type != KEY_RSA_CERT))
                return 0;
        nbits = EVP_PKEY_bits(k->pkey);
        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
int
sshkey_ecdsa_key_to_nid(const EC_KEY *k)
{
        const EC_GROUP *g;
        int nid;

        if (k == NULL || (g = EC_KEY_get0_group(k)) == NULL)
                return -1;
        if ((nid = EC_GROUP_get_curve_name(g)) <= 0)
                return -1;
        return nid;
}

int
sshkey_ecdsa_pkey_to_nid(EVP_PKEY *pkey)
{
        return sshkey_ecdsa_key_to_nid(EVP_PKEY_get0_EC_KEY(pkey));
}
#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 ((r = sshkey_prekey_alloc(&prekey, SSHKEY_SHIELD_PREKEY_LEN)) != 0)
                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(k, prvbuf)) != 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);
        sshkey_prekey_free(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 precedes 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 ((key->flags & SSHKEY_FLAG_EXT) != 0) {
                r = pkcs11_sign(key, sigp, lenp, data, datalen,
                    alg, sk_provider, sk_pin, compat);
        } 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 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) {
                *reason = "Certificate lacks principal list";
                return SSH_ERR_KEY_CERT_INVALID;
        }
        if (name == NULL)
                return 0; /* principal matching not requested */

        principal_matches = 0;
        for (i = 0; i < k->cert->nprincipals; i++) {
                if (wildcard_pattern) {
                        if (match_pattern(name, k->cert->principals[i])) {
                                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 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, wildcard_pattern,
            (uint64_t)now, name, reason);
}

int
sshkey_cert_check_host(const struct sshkey *key, const char *host,
    const char *ca_sign_algorithms, const char **reason)
{
        int r;

        if ((r = sshkey_cert_check_authority_now(key, 1, 1, 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;
}

static 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;
        } 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;

        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;
}

#ifdef WITH_OPENSSL
int
sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
{
        EC_POINT *nq = NULL;
        BIGNUM *order = NULL, *cofactor = NULL;
        int ret = SSH_ERR_KEY_INVALID_EC_VALUE;

        /*
         * NB. This assumes OpenSSL has already verified that the public
         * point lies on the curve and that its coordinates are in [0, p).
         * This is done by EC_POINT_oct2point() on at least OpenSSL >= 1.1,
         * LibreSSL and BoringSSL.
         */

        /* Q != infinity */
        if (EC_POINT_is_at_infinity(group, public))
                goto out;

        if ((cofactor = BN_new()) == NULL) {
                ret = SSH_ERR_ALLOC_FAIL;
                goto out;
        }
        if (EC_GROUP_get_cofactor(group, cofactor, NULL) != 1)
                goto out;

        /*
         * Verify nQ == infinity (n == order of subgroup)
         * This check may be skipped for curves with cofactor 1, as per
         * NIST SP 800-56A, 5.6.2.3.
         */
        if (!BN_is_one(cofactor)) {
                if ((order = BN_new()) == NULL) {
                        ret = SSH_ERR_ALLOC_FAIL;
                        goto out;
                }
                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;
        }

        /* success */
        ret = 0;
 out:
        BN_clear_free(cofactor);
        BN_clear_free(order);
        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_POINT_get_affine_coordinates(group, point, x, y, NULL) != 1) {
                fprintf(stderr, "%s: EC_POINT_get_affine_coordinates\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 */

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(prv, encrypted)) != 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 ((r = sshkey_unshield_private(key)) != 0)
                goto out;

        switch (key->type) {
        case KEY_ECDSA:
                if (format == SSHKEY_PRIVATE_PEM) {
                        success = PEM_write_bio_ECPrivateKey(bio,
                            EVP_PKEY_get0_EC_KEY(key->pkey),
                            cipher, passphrase, len, NULL, NULL);
                } else {
                        pkey = key->pkey;
                        EVP_PKEY_up_ref(key->pkey);
                        success = 1;
                }
                break;
        case KEY_RSA:
                if (format == SSHKEY_PRIVATE_PEM) {
                        success = PEM_write_bio_RSAPrivateKey(bio,
                            EVP_PKEY_get0_RSA(key->pkey),
                            cipher, passphrase, len, NULL, NULL);
                } else {
                        pkey = key->pkey;
                        EVP_PKEY_up_ref(key->pkey);
                        success = 1;
                }
                break;
#ifdef OPENSSL_HAS_ED25519
        case KEY_ED25519:
                if (format == SSHKEY_PRIVATE_PEM) {
                        r = SSH_ERR_INVALID_FORMAT;
                        goto out;
                } else {
                        pkey = EVP_PKEY_new_raw_private_key(EVP_PKEY_ED25519,
                            NULL, key->ed25519_sk,
                            ED25519_SK_SZ - ED25519_PK_SZ);
                        success = pkey != NULL;
                }
                break;
#endif
        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_ECDSA:
        case KEY_RSA:
        case KEY_ED25519:
                break; /* see below */
#else /* WITH_OPENSSL */
        case KEY_ED25519:
#endif /* WITH_OPENSSL */
        case KEY_ED25519_SK:
#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:
                case PEM_R_PROBLEMS_GETTING_PASSWORD:
                case PEM_R_BAD_DECRYPT:
                        return SSH_ERR_KEY_WRONG_PASSPHRASE;
                default:
                        return SSH_ERR_INVALID_FORMAT;
                }
        case ERR_LIB_EVP:
                switch (pem_reason) {
                case EVP_R_BAD_DECRYPT:
                        return SSH_ERR_KEY_WRONG_PASSPHRASE;
#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
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;
        RSA *rsa = NULL;
        EC_KEY *ecdsa = NULL;

        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, NULL,
            (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;
                }
                if ((rsa = EVP_PKEY_get1_RSA(pk)) == NULL) {
                        r = SSH_ERR_LIBCRYPTO_ERROR;
                        goto out;
                }
                prv->type = KEY_RSA;
#ifdef DEBUG_PK
                RSA_print_fp(stderr, rsa, 8);
#endif
                if (RSA_blinding_on(rsa, NULL) != 1 ||
                    EVP_PKEY_set1_RSA(pk, rsa) != 1) {
                        r = SSH_ERR_LIBCRYPTO_ERROR;
                        goto out;
                }
                EVP_PKEY_up_ref(pk);
                prv->pkey = pk;
                if ((r = sshkey_check_rsa_length(prv, 0)) != 0)
                        goto out;
        } 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;
                }
                if ((prv->ecdsa_nid = sshkey_ecdsa_fixup_group(pk)) == -1 ||
                    (ecdsa = EVP_PKEY_get1_EC_KEY(pk)) == NULL) {
                        r = SSH_ERR_LIBCRYPTO_ERROR;
                        goto out;
                }
                prv->type = KEY_ECDSA;
                if (sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
                    sshkey_ec_validate_public(EC_KEY_get0_group(ecdsa),
                    EC_KEY_get0_public_key(ecdsa)) != 0 ||
                    sshkey_ec_validate_private(ecdsa) != 0) {
                        r = SSH_ERR_INVALID_FORMAT;
                        goto out;
                }
                EVP_PKEY_up_ref(pk);
                prv->pkey = pk;
#ifdef DEBUG_PK
                if (prv != NULL && prv->pkey != NULL)
                        sshkey_dump_ec_key(EVP_PKEY_get0_EC_KEY(prv->pkey));
#endif
        } 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
        } 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);
        RSA_free(rsa);
        EC_KEY_free(ecdsa);
        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;

        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;
}