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/* $OpenBSD: sshkey.c,v 1.54 2017/07/01 13:50:45 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2008 Alexander von Gernler. All rights reserved.
* Copyright (c) 2010,2011 Damien Miller. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
#include <sys/types.h>
#include <netinet/in.h>
#ifdef WITH_OPENSSL
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#endif
#include "crypto_api.h"
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <resolv.h>
#ifdef HAVE_UTIL_H
#include <util.h>
#endif /* HAVE_UTIL_H */
#include "ssh2.h"
#include "ssherr.h"
#include "misc.h"
#include "sshbuf.h"
#include "cipher.h"
#include "digest.h"
#define SSHKEY_INTERNAL
#include "sshkey.h"
#include "match.h"
/* 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-cbc"
#define DEFAULT_ROUNDS 16
/* Version identification string for SSH v1 identity files. */
#define LEGACY_BEGIN "SSH PRIVATE KEY FILE FORMAT 1.1\n"
static int sshkey_from_blob_internal(struct sshbuf *buf,
struct sshkey **keyp, int allow_cert);
/* Supported key types */
struct keytype {
const char *name;
const char *shortname;
int type;
int nid;
int cert;
int sigonly;
};
static const struct keytype keytypes[] = {
{ "ssh-ed25519", "ED25519", KEY_ED25519, 0, 0, 0 },
{ "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT",
KEY_ED25519_CERT, 0, 1, 0 },
#ifdef WITH_OPENSSL
{ "ssh-rsa", "RSA", KEY_RSA, 0, 0, 0 },
{ "rsa-sha2-256", "RSA", KEY_RSA, 0, 0, 1 },
{ "rsa-sha2-512", "RSA", KEY_RSA, 0, 0, 1 },
{ "ssh-dss", "DSA", KEY_DSA, 0, 0, 0 },
# ifdef OPENSSL_HAS_ECC
{ "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0, 0 },
{ "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0, 0 },
# ifdef OPENSSL_HAS_NISTP521
{ "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0, 0 },
# endif /* OPENSSL_HAS_NISTP521 */
# endif /* OPENSSL_HAS_ECC */
{ "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1, 0 },
{ "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1, 0 },
# ifdef OPENSSL_HAS_ECC
{ "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT",
KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 },
{ "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT",
KEY_ECDSA_CERT, NID_secp384r1, 1, 0 },
# ifdef OPENSSL_HAS_NISTP521
{ "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT",
KEY_ECDSA_CERT, NID_secp521r1, 1, 0 },
# endif /* OPENSSL_HAS_NISTP521 */
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
{ NULL, NULL, -1, -1, 0, 0 }
};
const char *
sshkey_type(const struct sshkey *k)
{
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
if (kt->type == k->type)
return kt->shortname;
}
return "unknown";
}
static const char *
sshkey_ssh_name_from_type_nid(int type, int nid)
{
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
if (kt->type == type && (kt->nid == 0 || kt->nid == nid))
return kt->name;
}
return "ssh-unknown";
}
int
sshkey_type_is_cert(int type)
{
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
if (kt->type == type)
return kt->cert;
}
return 0;
}
const char *
sshkey_ssh_name(const struct sshkey *k)
{
return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid);
}
const char *
sshkey_ssh_name_plain(const struct sshkey *k)
{
return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type),
k->ecdsa_nid);
}
int
sshkey_type_from_name(const char *name)
{
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
/* Only allow shortname matches for plain key types */
if ((kt->name != NULL && strcmp(name, kt->name) == 0) ||
(!kt->cert && strcasecmp(kt->shortname, name) == 0))
return kt->type;
}
return KEY_UNSPEC;
}
int
sshkey_ecdsa_nid_from_name(const char *name)
{
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
if (kt->type != KEY_ECDSA && kt->type != KEY_ECDSA_CERT)
continue;
if (kt->name != NULL && strcmp(name, kt->name) == 0)
return kt->nid;
}
return -1;
}
char *
sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep)
{
char *tmp, *ret = NULL;
size_t nlen, rlen = 0;
const struct keytype *kt;
for (kt = keytypes; kt->type != -1; kt++) {
if (kt->name == NULL)
continue;
if (!include_sigonly && kt->sigonly)
continue;
if ((certs_only && !kt->cert) || (plain_only && kt->cert))
continue;
if (ret != NULL)
ret[rlen++] = sep;
nlen = strlen(kt->name);
if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
free(ret);
return NULL;
}
ret = tmp;
memcpy(ret + rlen, kt->name, nlen + 1);
rlen += nlen;
}
return ret;
}
int
sshkey_names_valid2(const char *names, int allow_wildcard)
{
char *s, *cp, *p;
const struct keytype *kt;
int 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.
*/
for (kt = keytypes; kt->type != -1; kt++) {
if (match_pattern_list(kt->name,
p, 0) != 0)
break;
}
if (kt->type != -1)
continue;
}
free(s);
return 0;
}
}
free(s);
return 1;
}
u_int
sshkey_size(const struct sshkey *k)
{
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
case KEY_RSA_CERT:
return BN_num_bits(k->rsa->n);
case KEY_DSA:
case KEY_DSA_CERT:
return BN_num_bits(k->dsa->p);
case KEY_ECDSA:
case KEY_ECDSA_CERT:
return sshkey_curve_nid_to_bits(k->ecdsa_nid);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
return 256; /* XXX */
}
return 0;
}
static int
sshkey_type_is_valid_ca(int type)
{
switch (type) {
case KEY_RSA:
case KEY_DSA:
case KEY_ECDSA:
case KEY_ED25519:
return 1;
default:
return 0;
}
}
int
sshkey_is_cert(const struct sshkey *k)
{
if (k == NULL)
return 0;
return sshkey_type_is_cert(k->type);
}
/* Return the cert-less equivalent to a certified key type */
int
sshkey_type_plain(int type)
{
switch (type) {
case KEY_RSA_CERT:
return KEY_RSA;
case KEY_DSA_CERT:
return KEY_DSA;
case KEY_ECDSA_CERT:
return KEY_ECDSA;
case KEY_ED25519_CERT:
return KEY_ED25519;
default:
return type;
}
}
#ifdef WITH_OPENSSL
/* XXX: these are really begging for a table-driven approach */
int
sshkey_curve_name_to_nid(const char *name)
{
if (strcmp(name, "nistp256") == 0)
return NID_X9_62_prime256v1;
else if (strcmp(name, "nistp384") == 0)
return NID_secp384r1;
# ifdef OPENSSL_HAS_NISTP521
else if (strcmp(name, "nistp521") == 0)
return NID_secp521r1;
# endif /* OPENSSL_HAS_NISTP521 */
else
return -1;
}
u_int
sshkey_curve_nid_to_bits(int nid)
{
switch (nid) {
case NID_X9_62_prime256v1:
return 256;
case NID_secp384r1:
return 384;
# ifdef OPENSSL_HAS_NISTP521
case NID_secp521r1:
return 521;
# endif /* OPENSSL_HAS_NISTP521 */
default:
return 0;
}
}
int
sshkey_ecdsa_bits_to_nid(int bits)
{
switch (bits) {
case 256:
return NID_X9_62_prime256v1;
case 384:
return NID_secp384r1;
# ifdef OPENSSL_HAS_NISTP521
case 521:
return NID_secp521r1;
# endif /* OPENSSL_HAS_NISTP521 */
default:
return -1;
}
}
const char *
sshkey_curve_nid_to_name(int nid)
{
switch (nid) {
case NID_X9_62_prime256v1:
return "nistp256";
case NID_secp384r1:
return "nistp384";
# ifdef OPENSSL_HAS_NISTP521
case NID_secp521r1:
return "nistp521";
# endif /* OPENSSL_HAS_NISTP521 */
default:
return NULL;
}
}
int
sshkey_ec_nid_to_hash_alg(int nid)
{
int kbits = sshkey_curve_nid_to_bits(nid);
if (kbits <= 0)
return -1;
/* RFC5656 section 6.2.1 */
if (kbits <= 256)
return SSH_DIGEST_SHA256;
else if (kbits <= 384)
return SSH_DIGEST_SHA384;
else
return SSH_DIGEST_SHA512;
}
#endif /* WITH_OPENSSL */
static void
cert_free(struct sshkey_cert *cert)
{
u_int i;
if (cert == NULL)
return;
sshbuf_free(cert->certblob);
sshbuf_free(cert->critical);
sshbuf_free(cert->extensions);
free(cert->key_id);
for (i = 0; i < cert->nprincipals; i++)
free(cert->principals[i]);
free(cert->principals);
sshkey_free(cert->signature_key);
explicit_bzero(cert, sizeof(*cert));
free(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;
return cert;
}
struct sshkey *
sshkey_new(int type)
{
struct sshkey *k;
#ifdef WITH_OPENSSL
RSA *rsa;
DSA *dsa;
#endif /* WITH_OPENSSL */
if ((k = calloc(1, sizeof(*k))) == NULL)
return NULL;
k->type = type;
k->ecdsa = NULL;
k->ecdsa_nid = -1;
k->dsa = NULL;
k->rsa = NULL;
k->cert = NULL;
k->ed25519_sk = NULL;
k->ed25519_pk = NULL;
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
case KEY_RSA_CERT:
if ((rsa = RSA_new()) == NULL ||
(rsa->n = BN_new()) == NULL ||
(rsa->e = BN_new()) == NULL) {
if (rsa != NULL)
RSA_free(rsa);
free(k);
return NULL;
}
k->rsa = rsa;
break;
case KEY_DSA:
case KEY_DSA_CERT:
if ((dsa = DSA_new()) == NULL ||
(dsa->p = BN_new()) == NULL ||
(dsa->q = BN_new()) == NULL ||
(dsa->g = BN_new()) == NULL ||
(dsa->pub_key = BN_new()) == NULL) {
if (dsa != NULL)
DSA_free(dsa);
free(k);
return NULL;
}
k->dsa = dsa;
break;
case KEY_ECDSA:
case KEY_ECDSA_CERT:
/* Cannot do anything until we know the group */
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
/* no need to prealloc */
break;
case KEY_UNSPEC:
break;
default:
free(k);
return NULL;
}
if (sshkey_is_cert(k)) {
if ((k->cert = cert_new()) == NULL) {
sshkey_free(k);
return NULL;
}
}
return k;
}
int
sshkey_add_private(struct sshkey *k)
{
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
case KEY_RSA_CERT:
#define bn_maybe_alloc_failed(p) (p == NULL && (p = BN_new()) == NULL)
if (bn_maybe_alloc_failed(k->rsa->d) ||
bn_maybe_alloc_failed(k->rsa->iqmp) ||
bn_maybe_alloc_failed(k->rsa->q) ||
bn_maybe_alloc_failed(k->rsa->p) ||
bn_maybe_alloc_failed(k->rsa->dmq1) ||
bn_maybe_alloc_failed(k->rsa->dmp1))
return SSH_ERR_ALLOC_FAIL;
break;
case KEY_DSA:
case KEY_DSA_CERT:
if (bn_maybe_alloc_failed(k->dsa->priv_key))
return SSH_ERR_ALLOC_FAIL;
break;
#undef bn_maybe_alloc_failed
case KEY_ECDSA:
case KEY_ECDSA_CERT:
/* Cannot do anything until we know the group */
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
/* no need to prealloc */
break;
case KEY_UNSPEC:
break;
default:
return SSH_ERR_INVALID_ARGUMENT;
}
return 0;
}
struct sshkey *
sshkey_new_private(int type)
{
struct sshkey *k = sshkey_new(type);
if (k == NULL)
return NULL;
if (sshkey_add_private(k) != 0) {
sshkey_free(k);
return NULL;
}
return k;
}
void
sshkey_free(struct sshkey *k)
{
if (k == NULL)
return;
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
case KEY_RSA_CERT:
if (k->rsa != NULL)
RSA_free(k->rsa);
k->rsa = NULL;
break;
case KEY_DSA:
case KEY_DSA_CERT:
if (k->dsa != NULL)
DSA_free(k->dsa);
k->dsa = NULL;
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
case KEY_ECDSA_CERT:
if (k->ecdsa != NULL)
EC_KEY_free(k->ecdsa);
k->ecdsa = NULL;
break;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
if (k->ed25519_pk) {
explicit_bzero(k->ed25519_pk, ED25519_PK_SZ);
free(k->ed25519_pk);
k->ed25519_pk = NULL;
}
if (k->ed25519_sk) {
explicit_bzero(k->ed25519_sk, ED25519_SK_SZ);
free(k->ed25519_sk);
k->ed25519_sk = NULL;
}
break;
case KEY_UNSPEC:
break;
default:
break;
}
if (sshkey_is_cert(k))
cert_free(k->cert);
explicit_bzero(k, sizeof(*k));
free(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;
}
/*
* 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)
{
#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
BN_CTX *bnctx;
#endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
if (a == NULL || b == NULL ||
sshkey_type_plain(a->type) != sshkey_type_plain(b->type))
return 0;
switch (a->type) {
#ifdef WITH_OPENSSL
case KEY_RSA_CERT:
case KEY_RSA:
return a->rsa != NULL && b->rsa != NULL &&
BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
BN_cmp(a->rsa->n, b->rsa->n) == 0;
case KEY_DSA_CERT:
case KEY_DSA:
return a->dsa != NULL && b->dsa != NULL &&
BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA_CERT:
case KEY_ECDSA:
if (a->ecdsa == NULL || b->ecdsa == NULL ||
EC_KEY_get0_public_key(a->ecdsa) == NULL ||
EC_KEY_get0_public_key(b->ecdsa) == NULL)
return 0;
if ((bnctx = BN_CTX_new()) == NULL)
return 0;
if (EC_GROUP_cmp(EC_KEY_get0_group(a->ecdsa),
EC_KEY_get0_group(b->ecdsa), bnctx) != 0 ||
EC_POINT_cmp(EC_KEY_get0_group(a->ecdsa),
EC_KEY_get0_public_key(a->ecdsa),
EC_KEY_get0_public_key(b->ecdsa), bnctx) != 0) {
BN_CTX_free(bnctx);
return 0;
}
BN_CTX_free(bnctx);
return 1;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
return a->ed25519_pk != NULL && b->ed25519_pk != NULL &&
memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) == 0;
default:
return 0;
}
/* NOTREACHED */
}
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);
}
static int
to_blob_buf(const struct sshkey *key, struct sshbuf *b, int force_plain)
{
int type, ret = SSH_ERR_INTERNAL_ERROR;
const char *typename;
if (key == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if (sshkey_is_cert(key)) {
if (key->cert == NULL)
return SSH_ERR_EXPECTED_CERT;
if (sshbuf_len(key->cert->certblob) == 0)
return SSH_ERR_KEY_LACKS_CERTBLOB;
}
type = force_plain ? sshkey_type_plain(key->type) : key->type;
typename = sshkey_ssh_name_from_type_nid(type, key->ecdsa_nid);
switch (type) {
#ifdef WITH_OPENSSL
case KEY_DSA_CERT:
case KEY_ECDSA_CERT:
case KEY_RSA_CERT:
#endif /* WITH_OPENSSL */
case KEY_ED25519_CERT:
/* Use the existing blob */
/* XXX modified flag? */
if ((ret = sshbuf_putb(b, key->cert->certblob)) != 0)
return ret;
break;
#ifdef WITH_OPENSSL
case KEY_DSA:
if (key->dsa == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->dsa->p)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->dsa->q)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->dsa->g)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->dsa->pub_key)) != 0)
return ret;
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
if (key->ecdsa == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
(ret = sshbuf_put_cstring(b,
sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 ||
(ret = sshbuf_put_eckey(b, key->ecdsa)) != 0)
return ret;
break;
# endif
case KEY_RSA:
if (key->rsa == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->rsa->e)) != 0 ||
(ret = sshbuf_put_bignum2(b, key->rsa->n)) != 0)
return ret;
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
if (key->ed25519_pk == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((ret = sshbuf_put_cstring(b, typename)) != 0 ||
(ret = sshbuf_put_string(b,
key->ed25519_pk, ED25519_PK_SZ)) != 0)
return ret;
break;
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
return 0;
}
int
sshkey_putb(const struct sshkey *key, struct sshbuf *b)
{
return to_blob_buf(key, b, 0);
}
int
sshkey_puts(const struct sshkey *key, struct sshbuf *b)
{
struct sshbuf *tmp;
int r;
if ((tmp = sshbuf_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
r = to_blob_buf(key, tmp, 0);
if (r == 0)
r = sshbuf_put_stringb(b, tmp);
sshbuf_free(tmp);
return r;
}
int
sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b)
{
return to_blob_buf(key, b, 1);
}
static int
to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain)
{
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)) != 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);
}
int
sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp)
{
return to_blob(key, blobp, lenp, 1);
}
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)) != 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) {
explicit_bzero(blob, blob_len);
free(blob);
}
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;
int r;
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 ((r = b64_ntop(dgst_raw, dgst_raw_len,
ret + plen, rlen - plen)) == -1) {
explicit_bzero(ret, rlen);
free(ret);
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:
explicit_bzero(dgst_raw, dgst_raw_len);
free(dgst_raw);
return NULL;
}
explicit_bzero(dgst_raw, dgst_raw_len);
free(dgst_raw);
return retval;
}
/* returns 0 ok, and < 0 error */
int
sshkey_read(struct sshkey *ret, char **cpp)
{
struct sshkey *k;
int retval = SSH_ERR_INVALID_FORMAT;
char *ep, *cp, *space;
int r, type, curve_nid = -1;
struct sshbuf *blob;
if (ret == NULL)
return SSH_ERR_INVALID_ARGUMENT;
cp = *cpp;
switch (ret->type) {
case KEY_UNSPEC:
case KEY_RSA:
case KEY_DSA:
case KEY_ECDSA:
case KEY_ED25519:
case KEY_DSA_CERT:
case KEY_ECDSA_CERT:
case KEY_RSA_CERT:
case KEY_ED25519_CERT:
space = strchr(cp, ' ');
if (space == NULL)
return SSH_ERR_INVALID_FORMAT;
*space = '\0';
type = sshkey_type_from_name(cp);
if (sshkey_type_plain(type) == KEY_ECDSA &&
(curve_nid = sshkey_ecdsa_nid_from_name(cp)) == -1)
return SSH_ERR_EC_CURVE_INVALID;
*space = ' ';
if (type == KEY_UNSPEC)
return SSH_ERR_INVALID_FORMAT;
cp = space+1;
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;
/* trim comment */
space = strchr(cp, ' ');
if (space) {
/* advance 'space': skip whitespace */
*space++ = '\0';
while (*space == ' ' || *space == '\t')
space++;
ep = space;
} else
ep = cp + strlen(cp);
if ((r = sshbuf_b64tod(blob, cp)) != 0) {
sshbuf_free(blob);
return r;
}
if ((r = sshkey_from_blob(sshbuf_ptr(blob),
sshbuf_len(blob), &k)) != 0) {
sshbuf_free(blob);
return r;
}
sshbuf_free(blob);
if (k->type != type) {
sshkey_free(k);
return SSH_ERR_KEY_TYPE_MISMATCH;
}
if (sshkey_type_plain(type) == KEY_ECDSA &&
curve_nid != k->ecdsa_nid) {
sshkey_free(k);
return SSH_ERR_EC_CURVE_MISMATCH;
}
ret->type = type;
if (sshkey_is_cert(ret)) {
if (!sshkey_is_cert(k)) {
sshkey_free(k);
return SSH_ERR_EXPECTED_CERT;
}
if (ret->cert != NULL)
cert_free(ret->cert);
ret->cert = k->cert;
k->cert = NULL;
}
switch (sshkey_type_plain(ret->type)) {
#ifdef WITH_OPENSSL
case KEY_RSA:
if (ret->rsa != NULL)
RSA_free(ret->rsa);
ret->rsa = k->rsa;
k->rsa = NULL;
#ifdef DEBUG_PK
RSA_print_fp(stderr, ret->rsa, 8);
#endif
break;
case KEY_DSA:
if (ret->dsa != NULL)
DSA_free(ret->dsa);
ret->dsa = k->dsa;
k->dsa = NULL;
#ifdef DEBUG_PK
DSA_print_fp(stderr, ret->dsa, 8);
#endif
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
if (ret->ecdsa != NULL)
EC_KEY_free(ret->ecdsa);
ret->ecdsa = k->ecdsa;
ret->ecdsa_nid = k->ecdsa_nid;
k->ecdsa = NULL;
k->ecdsa_nid = -1;
#ifdef DEBUG_PK
sshkey_dump_ec_key(ret->ecdsa);
#endif
break;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519:
free(ret->ed25519_pk);
ret->ed25519_pk = k->ed25519_pk;
k->ed25519_pk = NULL;
#ifdef DEBUG_PK
/* XXX */
#endif
break;
}
*cpp = ep;
retval = 0;
/*XXXX*/
sshkey_free(k);
if (retval != 0)
break;
break;
default:
return SSH_ERR_INVALID_ARGUMENT;
}
return retval;
}
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(b)) == 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";
}
}
#ifdef WITH_OPENSSL
static int
rsa_generate_private_key(u_int bits, RSA **rsap)
{
RSA *private = NULL;
BIGNUM *f4 = NULL;
int ret = SSH_ERR_INTERNAL_ERROR;
if (rsap == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
bits > SSHBUF_MAX_BIGNUM * 8)
return SSH_ERR_KEY_LENGTH;
*rsap = NULL;
if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (!BN_set_word(f4, RSA_F4) ||
!RSA_generate_key_ex(private, bits, f4, NULL)) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
*rsap = private;
private = NULL;
ret = 0;
out:
if (private != NULL)
RSA_free(private);
if (f4 != NULL)
BN_free(f4);
return ret;
}
static int
dsa_generate_private_key(u_int bits, DSA **dsap)
{
DSA *private;
int ret = SSH_ERR_INTERNAL_ERROR;
if (dsap == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if (bits != 1024)
return SSH_ERR_KEY_LENGTH;
if ((private = DSA_new()) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
*dsap = NULL;
if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL,
NULL, NULL) || !DSA_generate_key(private)) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
*dsap = private;
private = NULL;
ret = 0;
out:
if (private != NULL)
DSA_free(private);
return ret;
}
# ifdef OPENSSL_HAS_ECC
int
sshkey_ecdsa_key_to_nid(EC_KEY *k)
{
EC_GROUP *eg;
int nids[] = {
NID_X9_62_prime256v1,
NID_secp384r1,
# ifdef OPENSSL_HAS_NISTP521
NID_secp521r1,
# endif /* OPENSSL_HAS_NISTP521 */
-1
};
int nid;
u_int i;
BN_CTX *bnctx;
const EC_GROUP *g = EC_KEY_get0_group(k);
/*
* The group may be stored in a ASN.1 encoded private key in one of two
* ways: as a "named group", which is reconstituted by ASN.1 object ID
* or explicit group parameters encoded into the key blob. Only the
* "named group" case sets the group NID for us, but we can figure
* it out for the other case by comparing against all the groups that
* are supported.
*/
if ((nid = EC_GROUP_get_curve_name(g)) > 0)
return nid;
if ((bnctx = BN_CTX_new()) == NULL)
return -1;
for (i = 0; nids[i] != -1; i++) {
if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) {
BN_CTX_free(bnctx);
return -1;
}
if (EC_GROUP_cmp(g, eg, bnctx) == 0)
break;
EC_GROUP_free(eg);
}
BN_CTX_free(bnctx);
if (nids[i] != -1) {
/* Use the group with the NID attached */
EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE);
if (EC_KEY_set_group(k, eg) != 1) {
EC_GROUP_free(eg);
return -1;
}
}
return nids[i];
}
static int
ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap)
{
EC_KEY *private;
int ret = SSH_ERR_INTERNAL_ERROR;
if (nid == NULL || ecdsap == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1)
return SSH_ERR_KEY_LENGTH;
*ecdsap = NULL;
if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (EC_KEY_generate_key(private) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE);
*ecdsap = private;
private = NULL;
ret = 0;
out:
if (private != NULL)
EC_KEY_free(private);
return ret;
}
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
int
sshkey_generate(int type, u_int bits, struct sshkey **keyp)
{
struct sshkey *k;
int ret = SSH_ERR_INTERNAL_ERROR;
if (keyp == NULL)
return SSH_ERR_INVALID_ARGUMENT;
*keyp = NULL;
if ((k = sshkey_new(KEY_UNSPEC)) == NULL)
return SSH_ERR_ALLOC_FAIL;
switch (type) {
case KEY_ED25519:
if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL ||
(k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
break;
}
crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk);
ret = 0;
break;
#ifdef WITH_OPENSSL
case KEY_DSA:
ret = dsa_generate_private_key(bits, &k->dsa);
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid,
&k->ecdsa);
break;
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA:
ret = rsa_generate_private_key(bits, &k->rsa);
break;
#endif /* WITH_OPENSSL */
default:
ret = SSH_ERR_INVALID_ARGUMENT;
}
if (ret == 0) {
k->type = type;
*keyp = k;
} else
sshkey_free(k);
return ret;
}
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 ret = SSH_ERR_INTERNAL_ERROR;
if (to_key->cert != NULL) {
cert_free(to_key->cert);
to_key->cert = NULL;
}
if ((from = from_key->cert) == NULL)
return SSH_ERR_INVALID_ARGUMENT;
if ((to = to_key->cert = cert_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((ret = sshbuf_putb(to->certblob, from->certblob)) != 0 ||
(ret = sshbuf_putb(to->critical, from->critical)) != 0 ||
(ret = sshbuf_putb(to->extensions, from->extensions)) != 0)
return ret;
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)
return SSH_ERR_ALLOC_FAIL;
to->valid_after = from->valid_after;
to->valid_before = from->valid_before;
if (from->signature_key == NULL)
to->signature_key = NULL;
else if ((ret = sshkey_from_private(from->signature_key,
&to->signature_key)) != 0)
return ret;
if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS)
return SSH_ERR_INVALID_ARGUMENT;
if (from->nprincipals > 0) {
if ((to->principals = calloc(from->nprincipals,
sizeof(*to->principals))) == NULL)
return SSH_ERR_ALLOC_FAIL;
for (i = 0; i < from->nprincipals; i++) {
to->principals[i] = strdup(from->principals[i]);
if (to->principals[i] == NULL) {
to->nprincipals = i;
return SSH_ERR_ALLOC_FAIL;
}
}
}
to->nprincipals = from->nprincipals;
return 0;
}
int
sshkey_from_private(const struct sshkey *k, struct sshkey **pkp)
{
struct sshkey *n = NULL;
int ret = SSH_ERR_INTERNAL_ERROR;
*pkp = NULL;
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_DSA:
case KEY_DSA_CERT:
if ((n = sshkey_new(k->type)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((BN_copy(n->dsa->p, k->dsa->p) == NULL) ||
(BN_copy(n->dsa->q, k->dsa->q) == NULL) ||
(BN_copy(n->dsa->g, k->dsa->g) == NULL) ||
(BN_copy(n->dsa->pub_key, k->dsa->pub_key) == NULL)) {
sshkey_free(n);
return SSH_ERR_ALLOC_FAIL;
}
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
case KEY_ECDSA_CERT:
if ((n = sshkey_new(k->type)) == NULL)
return SSH_ERR_ALLOC_FAIL;
n->ecdsa_nid = k->ecdsa_nid;
n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid);
if (n->ecdsa == NULL) {
sshkey_free(n);
return SSH_ERR_ALLOC_FAIL;
}
if (EC_KEY_set_public_key(n->ecdsa,
EC_KEY_get0_public_key(k->ecdsa)) != 1) {
sshkey_free(n);
return SSH_ERR_LIBCRYPTO_ERROR;
}
break;
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA:
case KEY_RSA_CERT:
if ((n = sshkey_new(k->type)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if ((BN_copy(n->rsa->n, k->rsa->n) == NULL) ||
(BN_copy(n->rsa->e, k->rsa->e) == NULL)) {
sshkey_free(n);
return SSH_ERR_ALLOC_FAIL;
}
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
if ((n = sshkey_new(k->type)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if (k->ed25519_pk != NULL) {
if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) {
sshkey_free(n);
return SSH_ERR_ALLOC_FAIL;
}
memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ);
}
break;
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
if (sshkey_is_cert(k)) {
if ((ret = sshkey_cert_copy(k, n)) != 0) {
sshkey_free(n);
return ret;
}
}
*pkp = n;
return 0;
}
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, 0)) != 0)
goto out;
/* Success */
ret = 0;
out:
sshbuf_free(ca);
sshbuf_free(crit);
sshbuf_free(exts);
sshbuf_free(principals);
free(sig);
return ret;
}
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, *curve = NULL;
struct sshkey *key = NULL;
size_t len;
u_char *pk = NULL;
struct sshbuf *copy;
#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
EC_POINT *q = NULL;
#endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
#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;
}
switch (type) {
#ifdef WITH_OPENSSL
case KEY_RSA_CERT:
/* Skip nonce */
if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
/* FALLTHROUGH */
case KEY_RSA:
if ((key = sshkey_new(type)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (sshbuf_get_bignum2(b, key->rsa->e) != 0 ||
sshbuf_get_bignum2(b, key->rsa->n) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (BN_num_bits(key->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
ret = SSH_ERR_KEY_LENGTH;
goto out;
}
#ifdef DEBUG_PK
RSA_print_fp(stderr, key->rsa, 8);
#endif
break;
case KEY_DSA_CERT:
/* Skip nonce */
if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
/* FALLTHROUGH */
case KEY_DSA:
if ((key = sshkey_new(type)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (sshbuf_get_bignum2(b, key->dsa->p) != 0 ||
sshbuf_get_bignum2(b, key->dsa->q) != 0 ||
sshbuf_get_bignum2(b, key->dsa->g) != 0 ||
sshbuf_get_bignum2(b, key->dsa->pub_key) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
#ifdef DEBUG_PK
DSA_print_fp(stderr, key->dsa, 8);
#endif
break;
case KEY_ECDSA_CERT:
/* Skip nonce */
if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
/* FALLTHROUGH */
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
if ((key = sshkey_new(type)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
key->ecdsa_nid = sshkey_ecdsa_nid_from_name(ktype);
if (sshbuf_get_cstring(b, &curve, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (key->ecdsa_nid != sshkey_curve_name_to_nid(curve)) {
ret = SSH_ERR_EC_CURVE_MISMATCH;
goto out;
}
if (key->ecdsa != NULL)
EC_KEY_free(key->ecdsa);
if ((key->ecdsa = EC_KEY_new_by_curve_name(key->ecdsa_nid))
== NULL) {
ret = SSH_ERR_EC_CURVE_INVALID;
goto out;
}
if ((q = EC_POINT_new(EC_KEY_get0_group(key->ecdsa))) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (sshbuf_get_ec(b, q, EC_KEY_get0_group(key->ecdsa)) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (sshkey_ec_validate_public(EC_KEY_get0_group(key->ecdsa),
q) != 0) {
ret = SSH_ERR_KEY_INVALID_EC_VALUE;
goto out;
}
if (EC_KEY_set_public_key(key->ecdsa, q) != 1) {
/* XXX assume it is a allocation error */
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
#ifdef DEBUG_PK
sshkey_dump_ec_point(EC_KEY_get0_group(key->ecdsa), q);
#endif
break;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519_CERT:
/* Skip nonce */
if (sshbuf_get_string_direct(b, NULL, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
/* FALLTHROUGH */
case KEY_ED25519:
if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
goto out;
if (len != ED25519_PK_SZ) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((key = sshkey_new(type)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
key->ed25519_pk = pk;
pk = NULL;
break;
case KEY_UNSPEC:
if ((key = sshkey_new(type)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
break;
default:
ret = SSH_ERR_KEY_TYPE_UNKNOWN;
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);
free(curve);
free(pk);
#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
if (q != NULL)
EC_POINT_free(q);
#endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
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_sign(const struct sshkey *key,
u_char **sigp, size_t *lenp,
const u_char *data, size_t datalen, const char *alg, u_int compat)
{
if (sigp != NULL)
*sigp = NULL;
if (lenp != NULL)
*lenp = 0;
if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE)
return SSH_ERR_INVALID_ARGUMENT;
switch (key->type) {
#ifdef WITH_OPENSSL
case KEY_DSA_CERT:
case KEY_DSA:
return ssh_dss_sign(key, sigp, lenp, data, datalen, compat);
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA_CERT:
case KEY_ECDSA:
return ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat);
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA_CERT:
case KEY_RSA:
return ssh_rsa_sign(key, sigp, lenp, data, datalen, alg);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
return ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat);
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
}
/*
* ssh_key_verify returns 0 for a correct signature and < 0 on error.
*/
int
sshkey_verify(const struct sshkey *key,
const u_char *sig, size_t siglen,
const u_char *data, size_t dlen, u_int compat)
{
if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE)
return SSH_ERR_INVALID_ARGUMENT;
switch (key->type) {
#ifdef WITH_OPENSSL
case KEY_DSA_CERT:
case KEY_DSA:
return ssh_dss_verify(key, sig, siglen, data, dlen, compat);
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA_CERT:
case KEY_ECDSA:
return ssh_ecdsa_verify(key, sig, siglen, data, dlen, compat);
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA_CERT:
case KEY_RSA:
return ssh_rsa_verify(key, sig, siglen, data, dlen);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat);
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
}
/* Converts a private to a public key */
int
sshkey_demote(const struct sshkey *k, struct sshkey **dkp)
{
struct sshkey *pk;
int ret = SSH_ERR_INTERNAL_ERROR;
*dkp = NULL;
if ((pk = calloc(1, sizeof(*pk))) == NULL)
return SSH_ERR_ALLOC_FAIL;
pk->type = k->type;
pk->flags = k->flags;
pk->ecdsa_nid = k->ecdsa_nid;
pk->dsa = NULL;
pk->ecdsa = NULL;
pk->rsa = NULL;
pk->ed25519_pk = NULL;
pk->ed25519_sk = NULL;
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA_CERT:
if ((ret = sshkey_cert_copy(k, pk)) != 0)
goto fail;
/* FALLTHROUGH */
case KEY_RSA:
if ((pk->rsa = RSA_new()) == NULL ||
(pk->rsa->e = BN_dup(k->rsa->e)) == NULL ||
(pk->rsa->n = BN_dup(k->rsa->n)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto fail;
}
break;
case KEY_DSA_CERT:
if ((ret = sshkey_cert_copy(k, pk)) != 0)
goto fail;
/* FALLTHROUGH */
case KEY_DSA:
if ((pk->dsa = DSA_new()) == NULL ||
(pk->dsa->p = BN_dup(k->dsa->p)) == NULL ||
(pk->dsa->q = BN_dup(k->dsa->q)) == NULL ||
(pk->dsa->g = BN_dup(k->dsa->g)) == NULL ||
(pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto fail;
}
break;
case KEY_ECDSA_CERT:
if ((ret = sshkey_cert_copy(k, pk)) != 0)
goto fail;
/* FALLTHROUGH */
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
pk->ecdsa = EC_KEY_new_by_curve_name(pk->ecdsa_nid);
if (pk->ecdsa == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto fail;
}
if (EC_KEY_set_public_key(pk->ecdsa,
EC_KEY_get0_public_key(k->ecdsa)) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto fail;
}
break;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519_CERT:
if ((ret = sshkey_cert_copy(k, pk)) != 0)
goto fail;
/* FALLTHROUGH */
case KEY_ED25519:
if (k->ed25519_pk != NULL) {
if ((pk->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto fail;
}
memcpy(pk->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ);
}
break;
default:
ret = SSH_ERR_KEY_TYPE_UNKNOWN;
fail:
sshkey_free(pk);
return ret;
}
*dkp = pk;
return 0;
}
/* Convert a plain key to their _CERT equivalent */
int
sshkey_to_certified(struct sshkey *k)
{
int newtype;
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
newtype = KEY_RSA_CERT;
break;
case KEY_DSA:
newtype = KEY_DSA_CERT;
break;
case KEY_ECDSA:
newtype = KEY_ECDSA_CERT;
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
newtype = KEY_ED25519_CERT;
break;
default:
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,
sshkey_certify_signer *signer, void *signer_ctx)
{
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;
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 ((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;
/* XXX this substantially duplicates to_blob(); refactor */
switch (k->type) {
#ifdef WITH_OPENSSL
case KEY_DSA_CERT:
if ((ret = sshbuf_put_bignum2(cert, k->dsa->p)) != 0 ||
(ret = sshbuf_put_bignum2(cert, k->dsa->q)) != 0 ||
(ret = sshbuf_put_bignum2(cert, k->dsa->g)) != 0 ||
(ret = sshbuf_put_bignum2(cert, k->dsa->pub_key)) != 0)
goto out;
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA_CERT:
if ((ret = sshbuf_put_cstring(cert,
sshkey_curve_nid_to_name(k->ecdsa_nid))) != 0 ||
(ret = sshbuf_put_ec(cert,
EC_KEY_get0_public_key(k->ecdsa),
EC_KEY_get0_group(k->ecdsa))) != 0)
goto out;
break;
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA_CERT:
if ((ret = sshbuf_put_bignum2(cert, k->rsa->e)) != 0 ||
(ret = sshbuf_put_bignum2(cert, k->rsa->n)) != 0)
goto out;
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519_CERT:
if ((ret = sshbuf_put_string(cert,
k->ed25519_pk, ED25519_PK_SZ)) != 0)
goto out;
break;
default:
ret = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
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, 0, signer_ctx)) != 0)
goto out;
/* 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);
sshbuf_free(principals);
return ret;
}
static int
default_key_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
const u_char *data, size_t datalen,
const char *alg, u_int compat, void *ctx)
{
if (ctx != NULL)
return SSH_ERR_INVALID_ARGUMENT;
return sshkey_sign(key, sigp, lenp, data, datalen, alg, compat);
}
int
sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg)
{
return sshkey_certify_custom(k, ca, alg, default_key_sign, NULL);
}
int
sshkey_cert_check_authority(const struct sshkey *k,
int want_host, int require_principal,
const char *name, const char **reason)
{
u_int i, principal_matches;
time_t now = time(NULL);
if (reason != NULL)
*reason = NULL;
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 (now < 0) {
/* yikes - system clock before epoch! */
*reason = "Certificate invalid: not yet valid";
return SSH_ERR_KEY_CERT_INVALID;
}
if ((u_int64_t)now < k->cert->valid_after) {
*reason = "Certificate invalid: not yet valid";
return SSH_ERR_KEY_CERT_INVALID;
}
if ((u_int64_t)now >= k->cert->valid_before) {
*reason = "Certificate invalid: expired";
return SSH_ERR_KEY_CERT_INVALID;
}
if (k->cert->nprincipals == 0) {
if (require_principal) {
*reason = "Certificate lacks principal list";
return SSH_ERR_KEY_CERT_INVALID;
}
} else if (name != NULL) {
principal_matches = 0;
for (i = 0; i < k->cert->nprincipals; i++) {
if (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;
}
size_t
sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l)
{
char from[32], to[32], ret[64];
time_t tt;
struct tm *tm;
*from = *to = '\0';
if (cert->valid_after == 0 &&
cert->valid_before == 0xffffffffffffffffULL)
return strlcpy(s, "forever", l);
if (cert->valid_after != 0) {
/* XXX revisit INT_MAX in 2038 :) */
tt = cert->valid_after > INT_MAX ?
INT_MAX : cert->valid_after;
tm = localtime(&tt);
strftime(from, sizeof(from), "%Y-%m-%dT%H:%M:%S", tm);
}
if (cert->valid_before != 0xffffffffffffffffULL) {
/* XXX revisit INT_MAX in 2038 :) */
tt = cert->valid_before > INT_MAX ?
INT_MAX : cert->valid_before;
tm = localtime(&tt);
strftime(to, sizeof(to), "%Y-%m-%dT%H:%M:%S", tm);
}
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);
}
int
sshkey_private_serialize(const struct sshkey *key, struct sshbuf *b)
{
int r = SSH_ERR_INTERNAL_ERROR;
if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0)
goto out;
switch (key->type) {
#ifdef WITH_OPENSSL
case KEY_RSA:
if ((r = sshbuf_put_bignum2(b, key->rsa->n)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->e)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->d)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->iqmp)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->p)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->q)) != 0)
goto out;
break;
case KEY_RSA_CERT:
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 ||
(r = sshbuf_put_bignum2(b, key->rsa->d)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->iqmp)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->p)) != 0 ||
(r = sshbuf_put_bignum2(b, key->rsa->q)) != 0)
goto out;
break;
case KEY_DSA:
if ((r = sshbuf_put_bignum2(b, key->dsa->p)) != 0 ||
(r = sshbuf_put_bignum2(b, key->dsa->q)) != 0 ||
(r = sshbuf_put_bignum2(b, key->dsa->g)) != 0 ||
(r = sshbuf_put_bignum2(b, key->dsa->pub_key)) != 0 ||
(r = sshbuf_put_bignum2(b, key->dsa->priv_key)) != 0)
goto out;
break;
case KEY_DSA_CERT:
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 ||
(r = sshbuf_put_bignum2(b, key->dsa->priv_key)) != 0)
goto out;
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
if ((r = sshbuf_put_cstring(b,
sshkey_curve_nid_to_name(key->ecdsa_nid))) != 0 ||
(r = sshbuf_put_eckey(b, key->ecdsa)) != 0 ||
(r = sshbuf_put_bignum2(b,
EC_KEY_get0_private_key(key->ecdsa))) != 0)
goto out;
break;
case KEY_ECDSA_CERT:
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 ||
(r = sshbuf_put_bignum2(b,
EC_KEY_get0_private_key(key->ecdsa))) != 0)
goto out;
break;
# endif /* OPENSSL_HAS_ECC */
#endif /* WITH_OPENSSL */
case KEY_ED25519:
if ((r = sshbuf_put_string(b, key->ed25519_pk,
ED25519_PK_SZ)) != 0 ||
(r = sshbuf_put_string(b, key->ed25519_sk,
ED25519_SK_SZ)) != 0)
goto out;
break;
case KEY_ED25519_CERT:
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 ||
(r = sshbuf_put_string(b, key->ed25519_pk,
ED25519_PK_SZ)) != 0 ||
(r = sshbuf_put_string(b, key->ed25519_sk,
ED25519_SK_SZ)) != 0)
goto out;
break;
default:
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
/* success */
r = 0;
out:
return r;
}
int
sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp)
{
char *tname = NULL, *curve = NULL;
struct sshkey *k = NULL;
size_t pklen = 0, sklen = 0;
int type, r = SSH_ERR_INTERNAL_ERROR;
u_char *ed25519_pk = NULL, *ed25519_sk = NULL;
#ifdef WITH_OPENSSL
BIGNUM *exponent = NULL;
#endif /* WITH_OPENSSL */
if (kp != NULL)
*kp = NULL;
if ((r = sshbuf_get_cstring(buf, &tname, NULL)) != 0)
goto out;
type = sshkey_type_from_name(tname);
switch (type) {
#ifdef WITH_OPENSSL
case KEY_DSA:
if ((k = sshkey_new_private(type)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_get_bignum2(buf, k->dsa->p)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->dsa->q)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->dsa->g)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->dsa->pub_key)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->dsa->priv_key)) != 0)
goto out;
break;
case KEY_DSA_CERT:
if ((r = sshkey_froms(buf, &k)) != 0 ||
(r = sshkey_add_private(k)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->dsa->priv_key)) != 0)
goto out;
break;
# ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
if ((k = sshkey_new_private(type)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((k->ecdsa_nid = sshkey_ecdsa_nid_from_name(tname)) == -1) {
r = SSH_ERR_INVALID_ARGUMENT;
goto out;
}
if ((r = sshbuf_get_cstring(buf, &curve, NULL)) != 0)
goto out;
if (k->ecdsa_nid != sshkey_curve_name_to_nid(curve)) {
r = SSH_ERR_EC_CURVE_MISMATCH;
goto out;
}
k->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid);
if (k->ecdsa == NULL || (exponent = BN_new()) == NULL) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if ((r = sshbuf_get_eckey(buf, k->ecdsa)) != 0 ||
(r = sshbuf_get_bignum2(buf, exponent)))
goto out;
if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if ((r = sshkey_ec_validate_public(EC_KEY_get0_group(k->ecdsa),
EC_KEY_get0_public_key(k->ecdsa))) != 0 ||
(r = sshkey_ec_validate_private(k->ecdsa)) != 0)
goto out;
break;
case KEY_ECDSA_CERT:
if ((exponent = BN_new()) == NULL) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if ((r = sshkey_froms(buf, &k)) != 0 ||
(r = sshkey_add_private(k)) != 0 ||
(r = sshbuf_get_bignum2(buf, exponent)) != 0)
goto out;
if (EC_KEY_set_private_key(k->ecdsa, exponent) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if ((r = sshkey_ec_validate_public(EC_KEY_get0_group(k->ecdsa),
EC_KEY_get0_public_key(k->ecdsa))) != 0 ||
(r = sshkey_ec_validate_private(k->ecdsa)) != 0)
goto out;
break;
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA:
if ((k = sshkey_new_private(type)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_get_bignum2(buf, k->rsa->n)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->e)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->d)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->iqmp)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->p)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->q)) != 0 ||
(r = ssh_rsa_generate_additional_parameters(k)) != 0)
goto out;
if (BN_num_bits(k->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
r = SSH_ERR_KEY_LENGTH;
goto out;
}
break;
case KEY_RSA_CERT:
if ((r = sshkey_froms(buf, &k)) != 0 ||
(r = sshkey_add_private(k)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->d)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->iqmp)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->p)) != 0 ||
(r = sshbuf_get_bignum2(buf, k->rsa->q)) != 0 ||
(r = ssh_rsa_generate_additional_parameters(k)) != 0)
goto out;
if (BN_num_bits(k->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
r = SSH_ERR_KEY_LENGTH;
goto out;
}
break;
#endif /* WITH_OPENSSL */
case KEY_ED25519:
if ((k = sshkey_new_private(type)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
if ((r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
(r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
goto out;
if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
k->ed25519_pk = ed25519_pk;
k->ed25519_sk = ed25519_sk;
ed25519_pk = ed25519_sk = NULL;
break;
case KEY_ED25519_CERT:
if ((r = sshkey_froms(buf, &k)) != 0 ||
(r = sshkey_add_private(k)) != 0 ||
(r = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 ||
(r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0)
goto out;
if (pklen != ED25519_PK_SZ || sklen != ED25519_SK_SZ) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
k->ed25519_pk = ed25519_pk;
k->ed25519_sk = ed25519_sk;
ed25519_pk = ed25519_sk = NULL;
break;
default:
r = SSH_ERR_KEY_TYPE_UNKNOWN;
goto out;
}
#ifdef WITH_OPENSSL
/* enable blinding */
switch (k->type) {
case KEY_RSA:
case KEY_RSA_CERT:
if (RSA_blinding_on(k->rsa, NULL) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
break;
}
#endif /* WITH_OPENSSL */
/* success */
r = 0;
if (kp != NULL) {
*kp = k;
k = NULL;
}
out:
free(tname);
free(curve);
#ifdef WITH_OPENSSL
if (exponent != NULL)
BN_clear_free(exponent);
#endif /* WITH_OPENSSL */
sshkey_free(k);
if (ed25519_pk != NULL) {
explicit_bzero(ed25519_pk, pklen);
free(ed25519_pk);
}
if (ed25519_sk != NULL) {
explicit_bzero(ed25519_sk, sklen);
free(ed25519_sk);
}
return r;
}
#if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
int
sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public)
{
BN_CTX *bnctx;
EC_POINT *nq = NULL;
BIGNUM *order, *x, *y, *tmp;
int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
/*
* NB. This assumes OpenSSL has already verified that the public
* point lies on the curve. This is done by EC_POINT_oct2point()
* implicitly calling EC_POINT_is_on_curve(). If this code is ever
* reachable with public points not unmarshalled using
* EC_POINT_oct2point then the caller will need to explicitly check.
*/
if ((bnctx = BN_CTX_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
BN_CTX_start(bnctx);
/*
* We shouldn't ever hit this case because bignum_get_ecpoint()
* refuses to load GF2m points.
*/
if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
NID_X9_62_prime_field)
goto out;
/* Q != infinity */
if (EC_POINT_is_at_infinity(group, public))
goto out;
if ((x = BN_CTX_get(bnctx)) == NULL ||
(y = BN_CTX_get(bnctx)) == NULL ||
(order = BN_CTX_get(bnctx)) == NULL ||
(tmp = BN_CTX_get(bnctx)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
/* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */
if (EC_GROUP_get_order(group, order, bnctx) != 1 ||
EC_POINT_get_affine_coordinates_GFp(group, public,
x, y, bnctx) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (BN_num_bits(x) <= BN_num_bits(order) / 2 ||
BN_num_bits(y) <= BN_num_bits(order) / 2)
goto out;
/* nQ == infinity (n == order of subgroup) */
if ((nq = EC_POINT_new(group)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (EC_POINT_is_at_infinity(group, nq) != 1)
goto out;
/* x < order - 1, y < order - 1 */
if (!BN_sub(tmp, order, BN_value_one())) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0)
goto out;
ret = 0;
out:
BN_CTX_free(bnctx);
if (nq != NULL)
EC_POINT_free(nq);
return ret;
}
int
sshkey_ec_validate_private(const EC_KEY *key)
{
BN_CTX *bnctx;
BIGNUM *order, *tmp;
int ret = SSH_ERR_KEY_INVALID_EC_VALUE;
if ((bnctx = BN_CTX_new()) == NULL)
return SSH_ERR_ALLOC_FAIL;
BN_CTX_start(bnctx);
if ((order = BN_CTX_get(bnctx)) == NULL ||
(tmp = BN_CTX_get(bnctx)) == NULL) {
ret = SSH_ERR_ALLOC_FAIL;
goto out;
}
/* log2(private) > log2(order)/2 */
if (EC_GROUP_get_order(EC_KEY_get0_group(key), order, bnctx) != 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_CTX_free(bnctx);
return ret;
}
void
sshkey_dump_ec_point(const EC_GROUP *group, const EC_POINT *point)
{
BIGNUM *x, *y;
BN_CTX *bnctx;
if (point == NULL) {
fputs("point=(NULL)\n", stderr);
return;
}
if ((bnctx = BN_CTX_new()) == NULL) {
fprintf(stderr, "%s: BN_CTX_new failed\n", __func__);
return;
}
BN_CTX_start(bnctx);
if ((x = BN_CTX_get(bnctx)) == NULL ||
(y = BN_CTX_get(bnctx)) == NULL) {
fprintf(stderr, "%s: BN_CTX_get failed\n", __func__);
return;
}
if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) !=
NID_X9_62_prime_field) {
fprintf(stderr, "%s: group is not a prime field\n", __func__);
return;
}
if (EC_POINT_get_affine_coordinates_GFp(group, point, x, y,
bnctx) != 1) {
fprintf(stderr, "%s: EC_POINT_get_affine_coordinates_GFp\n",
__func__);
return;
}
fputs("x=", stderr);
BN_print_fp(stderr, x);
fputs("\ny=", stderr);
BN_print_fp(stderr, y);
fputs("\n", stderr);
BN_CTX_free(bnctx);
}
void
sshkey_dump_ec_key(const EC_KEY *key)
{
const BIGNUM *exponent;
sshkey_dump_ec_point(EC_KEY_get0_group(key),
EC_KEY_get0_public_key(key));
fputs("exponent=", stderr);
if ((exponent = EC_KEY_get0_private_key(key)) == NULL)
fputs("(NULL)", stderr);
else
BN_print_fp(stderr, EC_KEY_get0_private_key(key));
fputs("\n", stderr);
}
#endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
static int
sshkey_private_to_blob2(const 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];
char *b64 = NULL;
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;
/* uuencode */
if ((b64 = sshbuf_dtob64(encoded)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
sshbuf_reset(blob);
if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0)
goto out;
for (i = 0; i < strlen(b64); i++) {
if ((r = sshbuf_put_u8(blob, b64[i])) != 0)
goto out;
/* insert line breaks */
if (i % 70 == 69 && (r = sshbuf_put_u8(blob, '\n')) != 0)
goto out;
}
if (i % 70 != 69 && (r = sshbuf_put_u8(blob, '\n')) != 0)
goto out;
if ((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) {
explicit_bzero(key, keylen + ivlen);
free(key);
}
if (pubkeyblob != NULL) {
explicit_bzero(pubkeyblob, pubkeylen);
free(pubkeyblob);
}
if (b64 != NULL) {
explicit_bzero(b64, strlen(b64));
free(b64);
}
return r;
}
static int
sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase,
struct sshkey **keyp, char **commentp)
{
char *comment = NULL, *ciphername = NULL, *kdfname = NULL;
const struct sshcipher *cipher = NULL;
const u_char *cp;
int r = SSH_ERR_INTERNAL_ERROR;
size_t encoded_len;
size_t i, keylen = 0, ivlen = 0, authlen = 0, slen = 0;
struct sshbuf *encoded = NULL, *decoded = NULL;
struct sshbuf *kdf = NULL, *decrypted = NULL;
struct sshcipher_ctx *ciphercontext = NULL;
struct sshkey *k = NULL;
u_char *key = NULL, *salt = NULL, *dp, pad, last;
u_int blocksize, rounds, nkeys, encrypted_len, check1, check2;
if (keyp != NULL)
*keyp = NULL;
if (commentp != NULL)
*commentp = NULL;
if ((encoded = sshbuf_new()) == NULL ||
(decoded = sshbuf_new()) == NULL ||
(decrypted = 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;
}
/* 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 ||
(r = sshbuf_skip_string(decoded)) != 0 || /* pubkey */
(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 ((passphrase == NULL || strlen(passphrase) == 0) &&
strcmp(ciphername, "none") != 0) {
/* passphrase required */
r = SSH_ERR_KEY_WRONG_PASSPHRASE;
goto out;
}
if (strcmp(kdfname, "none") != 0 && strcmp(kdfname, "bcrypt") != 0) {
r = SSH_ERR_KEY_UNKNOWN_CIPHER;
goto out;
}
if (!strcmp(kdfname, "none") && strcmp(ciphername, "none") != 0) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
if (nkeys != 1) {
/* XXX only one key supported */
r = SSH_ERR_INVALID_FORMAT;
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) < encrypted_len + authlen) {
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;
}
/* 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 */
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;
}
}
/* XXX decode pubkey and check against private */
/* success */
r = 0;
if (keyp != NULL) {
*keyp = k;
k = NULL;
}
if (commentp != NULL) {
*commentp = comment;
comment = NULL;
}
out:
pad = 0;
cipher_free(ciphercontext);
free(ciphername);
free(kdfname);
free(comment);
if (salt != NULL) {
explicit_bzero(salt, slen);
free(salt);
}
if (key != NULL) {
explicit_bzero(key, keylen + ivlen);
free(key);
}
sshbuf_free(encoded);
sshbuf_free(decoded);
sshbuf_free(kdf);
sshbuf_free(decrypted);
sshkey_free(k);
return r;
}
#ifdef WITH_OPENSSL
/* convert SSH v2 key in OpenSSL PEM format */
static int
sshkey_private_pem_to_blob(struct sshkey *key, struct sshbuf *blob,
const char *_passphrase, const char *comment)
{
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;
const u_char *bptr;
BIO *bio = NULL;
if (len > 0 && len <= 4)
return SSH_ERR_PASSPHRASE_TOO_SHORT;
if ((bio = BIO_new(BIO_s_mem())) == NULL)
return SSH_ERR_ALLOC_FAIL;
switch (key->type) {
case KEY_DSA:
success = PEM_write_bio_DSAPrivateKey(bio, key->dsa,
cipher, passphrase, len, NULL, NULL);
break;
#ifdef OPENSSL_HAS_ECC
case KEY_ECDSA:
success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa,
cipher, passphrase, len, NULL, NULL);
break;
#endif
case KEY_RSA:
success = PEM_write_bio_RSAPrivateKey(bio, key->rsa,
cipher, passphrase, len, NULL, NULL);
break;
default:
success = 0;
break;
}
if (success == 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:
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 force_new_format, const char *new_format_cipher, int new_format_rounds)
{
switch (key->type) {
#ifdef WITH_OPENSSL
case KEY_DSA:
case KEY_ECDSA:
case KEY_RSA:
if (force_new_format) {
return sshkey_private_to_blob2(key, blob, passphrase,
comment, new_format_cipher, new_format_rounds);
}
return sshkey_private_pem_to_blob(key, blob,
passphrase, comment);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
return sshkey_private_to_blob2(key, blob, passphrase,
comment, new_format_cipher, new_format_rounds);
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
}
#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;
case EVP_R_BN_DECODE_ERROR:
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;
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) {
r = convert_libcrypto_error();
goto out;
}
if (pk->type == EVP_PKEY_RSA &&
(type == KEY_UNSPEC || type == KEY_RSA)) {
if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
prv->rsa = EVP_PKEY_get1_RSA(pk);
prv->type = KEY_RSA;
#ifdef DEBUG_PK
RSA_print_fp(stderr, prv->rsa, 8);
#endif
if (RSA_blinding_on(prv->rsa, NULL) != 1) {
r = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
if (BN_num_bits(prv->rsa->n) < SSH_RSA_MINIMUM_MODULUS_SIZE) {
r = SSH_ERR_KEY_LENGTH;
goto out;
}
} else if (pk->type == EVP_PKEY_DSA &&
(type == KEY_UNSPEC || type == KEY_DSA)) {
if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
prv->dsa = EVP_PKEY_get1_DSA(pk);
prv->type = KEY_DSA;
#ifdef DEBUG_PK
DSA_print_fp(stderr, prv->dsa, 8);
#endif
#ifdef OPENSSL_HAS_ECC
} else if (pk->type == EVP_PKEY_EC &&
(type == KEY_UNSPEC || type == KEY_ECDSA)) {
if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) {
r = SSH_ERR_ALLOC_FAIL;
goto out;
}
prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk);
prv->type = KEY_ECDSA;
prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa);
if (prv->ecdsa_nid == -1 ||
sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL ||
sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa),
EC_KEY_get0_public_key(prv->ecdsa)) != 0 ||
sshkey_ec_validate_private(prv->ecdsa) != 0) {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
# ifdef DEBUG_PK
if (prv != NULL && prv->ecdsa != NULL)
sshkey_dump_ec_key(prv->ecdsa);
# endif
#endif /* OPENSSL_HAS_ECC */
} else {
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
r = 0;
if (keyp != NULL) {
*keyp = prv;
prv = NULL;
}
out:
BIO_free(bio);
if (pk != NULL)
EVP_PKEY_free(pk);
sshkey_free(prv);
return r;
}
#endif /* WITH_OPENSSL */
int
sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
const char *passphrase, struct sshkey **keyp, char **commentp)
{
int r = SSH_ERR_INTERNAL_ERROR;
if (keyp != NULL)
*keyp = NULL;
if (commentp != NULL)
*commentp = NULL;
switch (type) {
#ifdef WITH_OPENSSL
case KEY_DSA:
case KEY_ECDSA:
case KEY_RSA:
return sshkey_parse_private_pem_fileblob(blob, type,
passphrase, keyp);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
return sshkey_parse_private2(blob, type, passphrase,
keyp, commentp);
case KEY_UNSPEC:
r = sshkey_parse_private2(blob, type, passphrase, keyp,
commentp);
/* Do not fallback to PEM parser if only passphrase is wrong. */
if (r == 0 || r == SSH_ERR_KEY_WRONG_PASSPHRASE)
return r;
#ifdef WITH_OPENSSL
return sshkey_parse_private_pem_fileblob(blob, type,
passphrase, keyp);
#else
return SSH_ERR_INVALID_FORMAT;
#endif /* WITH_OPENSSL */
default:
return SSH_ERR_KEY_TYPE_UNKNOWN;
}
}
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);
}
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