diff options
Diffstat (limited to 'crypto/openssh/sshkey.c')
| -rw-r--r-- | crypto/openssh/sshkey.c | 3895 |
1 files changed, 3895 insertions, 0 deletions
diff --git a/crypto/openssh/sshkey.c b/crypto/openssh/sshkey.c new file mode 100644 index 0000000..32dd8f2 --- /dev/null +++ b/crypto/openssh/sshkey.c @@ -0,0 +1,3895 @@ +/* $OpenBSD: sshkey.c,v 1.21 2015/08/19 23:19:01 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/param.h> /* MIN MAX */ +#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 "rsa.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; +}; +static const struct keytype keytypes[] = { + { "ssh-ed25519", "ED25519", KEY_ED25519, 0, 0 }, + { "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT", + KEY_ED25519_CERT, 0, 1 }, +#ifdef WITH_OPENSSL + { NULL, "RSA1", KEY_RSA1, 0, 0 }, + { "ssh-rsa", "RSA", KEY_RSA, 0, 0 }, + { "ssh-dss", "DSA", KEY_DSA, 0, 0 }, +# ifdef OPENSSL_HAS_ECC + { "ecdsa-sha2-nistp256", "ECDSA", KEY_ECDSA, NID_X9_62_prime256v1, 0 }, + { "ecdsa-sha2-nistp384", "ECDSA", KEY_ECDSA, NID_secp384r1, 0 }, +# ifdef OPENSSL_HAS_NISTP521 + { "ecdsa-sha2-nistp521", "ECDSA", KEY_ECDSA, NID_secp521r1, 0 }, +# endif /* OPENSSL_HAS_NISTP521 */ +# endif /* OPENSSL_HAS_ECC */ + { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", KEY_RSA_CERT, 0, 1 }, + { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", KEY_DSA_CERT, 0, 1 }, +# ifdef OPENSSL_HAS_ECC + { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", + KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1 }, + { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", + KEY_ECDSA_CERT, NID_secp384r1, 1 }, +# ifdef OPENSSL_HAS_NISTP521 + { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", + KEY_ECDSA_CERT, NID_secp521r1, 1 }, +# endif /* OPENSSL_HAS_NISTP521 */ +# endif /* OPENSSL_HAS_ECC */ +#endif /* WITH_OPENSSL */ + { NULL, NULL, -1, -1, 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 * +key_alg_list(int certs_only, int plain_only) +{ + 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 ((certs_only && !kt->cert) || (plain_only && kt->cert)) + continue; + if (ret != NULL) + ret[rlen++] = '\n'; + 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_RSA1) { + free(s); + return 0; + } + 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 (kt->type == KEY_RSA1) + continue; + 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_RSA1: + 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; + if (cert->certblob != NULL) + sshbuf_free(cert->certblob); + if (cert->critical != NULL) + sshbuf_free(cert->critical); + if (cert->extensions != NULL) + sshbuf_free(cert->extensions); + if (cert->key_id != NULL) + free(cert->key_id); + for (i = 0; i < cert->nprincipals; i++) + free(cert->principals[i]); + if (cert->principals != NULL) + free(cert->principals); + if (cert->signature_key != NULL) + 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_RSA1: + 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; + break; + } + + 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_RSA1: + 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_RSA1: + 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_RSA1: + 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 (k->type == KEY_RSA1) { +#ifdef WITH_OPENSSL + int nlen = BN_num_bytes(k->rsa->n); + int elen = BN_num_bytes(k->rsa->e); + + blob_len = nlen + elen; + if (nlen >= INT_MAX - elen || + (blob = malloc(blob_len)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + BN_bn2bin(k->rsa->n, blob); + BN_bn2bin(k->rsa->e, blob + nlen); +#endif /* WITH_OPENSSL */ + } else 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 = MAX(x, 0); + y = MAX(y, 0); + x = MIN(x, FLDSIZE_X - 1); + y = MIN(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[MIN(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; +} + +#ifdef WITH_SSH1 +/* + * Reads a multiple-precision integer in decimal from the buffer, and advances + * the pointer. The integer must already be initialized. This function is + * permitted to modify the buffer. This leaves *cpp to point just beyond the + * last processed character. + */ +static int +read_decimal_bignum(char **cpp, BIGNUM *v) +{ + char *cp; + size_t e; + int skip = 1; /* skip white space */ + + cp = *cpp; + while (*cp == ' ' || *cp == '\t') + cp++; + e = strspn(cp, "0123456789"); + if (e == 0) + return SSH_ERR_INVALID_FORMAT; + if (e > SSHBUF_MAX_BIGNUM * 3) + return SSH_ERR_BIGNUM_TOO_LARGE; + if (cp[e] == '\0') + skip = 0; + else if (index(" \t\r\n", cp[e]) == NULL) + return SSH_ERR_INVALID_FORMAT; + cp[e] = '\0'; + if (BN_dec2bn(&v, cp) <= 0) + return SSH_ERR_INVALID_FORMAT; + *cpp = cp + e + skip; + return 0; +} +#endif /* WITH_SSH1 */ + +/* returns 0 ok, and < 0 error */ +int +sshkey_read(struct sshkey *ret, char **cpp) +{ + struct sshkey *k; + int retval = SSH_ERR_INVALID_FORMAT; + char *cp, *space; + int r, type, curve_nid = -1; + struct sshbuf *blob; +#ifdef WITH_SSH1 + char *ep; + u_long bits; +#endif /* WITH_SSH1 */ + + cp = *cpp; + + switch (ret->type) { + case KEY_RSA1: +#ifdef WITH_SSH1 + /* Get number of bits. */ + bits = strtoul(cp, &ep, 10); + if (*cp == '\0' || index(" \t\r\n", *ep) == NULL || + bits == 0 || bits > SSHBUF_MAX_BIGNUM * 8) + return SSH_ERR_INVALID_FORMAT; /* Bad bit count... */ + /* Get public exponent, public modulus. */ + if ((r = read_decimal_bignum(&ep, ret->rsa->e)) < 0) + return r; + if ((r = read_decimal_bignum(&ep, ret->rsa->n)) < 0) + return r; + *cpp = ep; + /* validate the claimed number of bits */ + if (BN_num_bits(ret->rsa->n) != (int)bits) + return SSH_ERR_KEY_BITS_MISMATCH; + retval = 0; +#endif /* WITH_SSH1 */ + break; + 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++; + *cpp = space; + } else + *cpp = 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; + } +#ifdef WITH_OPENSSL + if (sshkey_type_plain(ret->type) == 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 + } + if (sshkey_type_plain(ret->type) == 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 + } +# ifdef OPENSSL_HAS_ECC + if (sshkey_type_plain(ret->type) == 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 + } +# endif /* OPENSSL_HAS_ECC */ +#endif /* WITH_OPENSSL */ + if (sshkey_type_plain(ret->type) == KEY_ED25519) { + free(ret->ed25519_pk); + ret->ed25519_pk = k->ed25519_pk; + k->ed25519_pk = NULL; +#ifdef DEBUG_PK + /* XXX */ +#endif + } + 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; +} + +static int +sshkey_format_rsa1(const struct sshkey *key, struct sshbuf *b) +{ + int r = SSH_ERR_INTERNAL_ERROR; +#ifdef WITH_SSH1 + u_int bits = 0; + char *dec_e = NULL, *dec_n = NULL; + + if (key->rsa == NULL || key->rsa->e == NULL || + key->rsa->n == NULL) { + r = SSH_ERR_INVALID_ARGUMENT; + goto out; + } + if ((dec_e = BN_bn2dec(key->rsa->e)) == NULL || + (dec_n = BN_bn2dec(key->rsa->n)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + /* size of modulus 'n' */ + if ((bits = BN_num_bits(key->rsa->n)) <= 0) { + r = SSH_ERR_INVALID_ARGUMENT; + goto out; + } + if ((r = sshbuf_putf(b, "%u %s %s", bits, dec_e, dec_n)) != 0) + goto out; + + /* Success */ + r = 0; + out: + if (dec_e != NULL) + OPENSSL_free(dec_e); + if (dec_n != NULL) + OPENSSL_free(dec_n); +#endif /* WITH_SSH1 */ + + return r; +} + +static int +sshkey_format_text(const struct sshkey *key, struct sshbuf *b) +{ + int r = SSH_ERR_INTERNAL_ERROR; + char *uu = NULL; + + if (key->type == KEY_RSA1) { + if ((r = sshkey_format_rsa1(key, b)) != 0) + goto out; + } else { + /* Unsupported key types handled in sshkey_to_base64() */ + 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 || + bits < SSH_RSA_MINIMUM_MODULUS_SIZE || + bits > SSHBUF_MAX_BIGNUM * 8) + return SSH_ERR_INVALID_ARGUMENT; + *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 || bits != 1024) + return SSH_ERR_INVALID_ARGUMENT; + 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 || + (*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1) + return SSH_ERR_INVALID_ARGUMENT; + *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: + case KEY_RSA1: + 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; + + if (pkp != NULL) + *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_RSA1: + 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 = reallocarray(key->cert->principals, + 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 + *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; + } +#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; + *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, 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, compat); +#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, compat); +#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; + + if (dkp != NULL) + *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_RSA1: + 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(struct sshkey *k, struct sshkey *ca) +{ + 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 = sshkey_sign(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), + sshbuf_len(cert), 0)) != 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); + if (sig_blob != NULL) + free(sig_blob); + if (ca_blob != NULL) + free(ca_blob); + if (principals != NULL) + sshbuf_free(principals); + return ret; +} + +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; +} + +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 = rsa_generate_additional_parameters(k->rsa)) != 0) + 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 = rsa_generate_additional_parameters(k->rsa)) != 0) + 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: + case KEY_RSA1: + 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; + + 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; + const struct sshcipher *cipher; + const char *kdfname = KDFNAME; + struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL; + + memset(&ciphercontext, 0, sizeof(ciphercontext)); + + if (rounds <= 0) + rounds = DEFAULT_ROUNDS; + if (passphrase == NULL || !strlen(passphrase)) { + ciphername = "none"; + kdfname = "none"; + } else if (ciphername == NULL) + ciphername = DEFAULT_CIPHERNAME; + else if (cipher_number(ciphername) != SSH_CIPHER_SSH2) { + r = SSH_ERR_INVALID_ARGUMENT; + goto out; + } + if ((cipher = cipher_by_name(ciphername)) == NULL) { + r = SSH_ERR_INTERNAL_ERROR; + 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_cleanup(&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; + struct sshkey *k = NULL; + u_char *key = NULL, *salt = NULL, *dp, pad, last; + u_int blocksize, rounds, nkeys, encrypted_len, check1, check2; + + memset(&ciphercontext, 0, sizeof(ciphercontext)); + 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_cleanup(&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; +} + +#if WITH_SSH1 +/* + * Serialises the authentication (private) key to a blob, encrypting it with + * passphrase. The identification of the blob (lowest 64 bits of n) will + * precede the key to provide identification of the key without needing a + * passphrase. + */ +static int +sshkey_private_rsa1_to_blob(struct sshkey *key, struct sshbuf *blob, + const char *passphrase, const char *comment) +{ + struct sshbuf *buffer = NULL, *encrypted = NULL; + u_char buf[8]; + int r, cipher_num; + struct sshcipher_ctx ciphercontext; + const struct sshcipher *cipher; + u_char *cp; + + /* + * If the passphrase is empty, use SSH_CIPHER_NONE to ease converting + * to another cipher; otherwise use SSH_AUTHFILE_CIPHER. + */ + cipher_num = (strcmp(passphrase, "") == 0) ? + SSH_CIPHER_NONE : SSH_CIPHER_3DES; + if ((cipher = cipher_by_number(cipher_num)) == NULL) + return SSH_ERR_INTERNAL_ERROR; + + /* This buffer is used to build the secret part of the private key. */ + if ((buffer = sshbuf_new()) == NULL) + return SSH_ERR_ALLOC_FAIL; + + /* Put checkbytes for checking passphrase validity. */ + if ((r = sshbuf_reserve(buffer, 4, &cp)) != 0) + goto out; + arc4random_buf(cp, 2); + memcpy(cp + 2, cp, 2); + + /* + * Store the private key (n and e will not be stored because they + * will be stored in plain text, and storing them also in encrypted + * format would just give known plaintext). + * Note: q and p are stored in reverse order to SSL. + */ + if ((r = sshbuf_put_bignum1(buffer, key->rsa->d)) != 0 || + (r = sshbuf_put_bignum1(buffer, key->rsa->iqmp)) != 0 || + (r = sshbuf_put_bignum1(buffer, key->rsa->q)) != 0 || + (r = sshbuf_put_bignum1(buffer, key->rsa->p)) != 0) + goto out; + + /* Pad the part to be encrypted to a size that is a multiple of 8. */ + explicit_bzero(buf, 8); + if ((r = sshbuf_put(buffer, buf, 8 - (sshbuf_len(buffer) % 8))) != 0) + goto out; + + /* This buffer will be used to contain the data in the file. */ + if ((encrypted = sshbuf_new()) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + + /* First store keyfile id string. */ + if ((r = sshbuf_put(encrypted, LEGACY_BEGIN, + sizeof(LEGACY_BEGIN))) != 0) + goto out; + + /* Store cipher type and "reserved" field. */ + if ((r = sshbuf_put_u8(encrypted, cipher_num)) != 0 || + (r = sshbuf_put_u32(encrypted, 0)) != 0) + goto out; + + /* Store public key. This will be in plain text. */ + if ((r = sshbuf_put_u32(encrypted, BN_num_bits(key->rsa->n))) != 0 || + (r = sshbuf_put_bignum1(encrypted, key->rsa->n) != 0) || + (r = sshbuf_put_bignum1(encrypted, key->rsa->e) != 0) || + (r = sshbuf_put_cstring(encrypted, comment) != 0)) + goto out; + + /* Allocate space for the private part of the key in the buffer. */ + if ((r = sshbuf_reserve(encrypted, sshbuf_len(buffer), &cp)) != 0) + goto out; + + if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase, + CIPHER_ENCRYPT)) != 0) + goto out; + if ((r = cipher_crypt(&ciphercontext, 0, cp, + sshbuf_ptr(buffer), sshbuf_len(buffer), 0, 0)) != 0) + goto out; + if ((r = cipher_cleanup(&ciphercontext)) != 0) + goto out; + + r = sshbuf_putb(blob, encrypted); + + out: + explicit_bzero(&ciphercontext, sizeof(ciphercontext)); + explicit_bzero(buf, sizeof(buf)); + if (buffer != NULL) + sshbuf_free(buffer); + if (encrypted != NULL) + sshbuf_free(encrypted); + + return r; +} +#endif /* WITH_SSH1 */ + +#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; +#if (OPENSSL_VERSION_NUMBER < 0x00907000L) + const EVP_CIPHER *cipher = (len > 0) ? EVP_des_ede3_cbc() : NULL; +#else + const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL; +#endif + 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_SSH1 + case KEY_RSA1: + return sshkey_private_rsa1_to_blob(key, blob, + passphrase, comment); +#endif /* WITH_SSH1 */ +#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_SSH1 +/* + * Parse the public, unencrypted portion of a RSA1 key. + */ +int +sshkey_parse_public_rsa1_fileblob(struct sshbuf *blob, + struct sshkey **keyp, char **commentp) +{ + int r; + struct sshkey *pub = NULL; + struct sshbuf *copy = NULL; + + if (keyp != NULL) + *keyp = NULL; + if (commentp != NULL) + *commentp = NULL; + + /* Check that it is at least big enough to contain the ID string. */ + if (sshbuf_len(blob) < sizeof(LEGACY_BEGIN)) + return SSH_ERR_INVALID_FORMAT; + + /* + * Make sure it begins with the id string. Consume the id string + * from the buffer. + */ + if (memcmp(sshbuf_ptr(blob), LEGACY_BEGIN, sizeof(LEGACY_BEGIN)) != 0) + return SSH_ERR_INVALID_FORMAT; + /* Make a working copy of the keyblob and skip past the magic */ + if ((copy = sshbuf_fromb(blob)) == NULL) + return SSH_ERR_ALLOC_FAIL; + if ((r = sshbuf_consume(copy, sizeof(LEGACY_BEGIN))) != 0) + goto out; + + /* Skip cipher type, reserved data and key bits. */ + if ((r = sshbuf_get_u8(copy, NULL)) != 0 || /* cipher type */ + (r = sshbuf_get_u32(copy, NULL)) != 0 || /* reserved */ + (r = sshbuf_get_u32(copy, NULL)) != 0) /* key bits */ + goto out; + + /* Read the public key from the buffer. */ + if ((pub = sshkey_new(KEY_RSA1)) == NULL || + (r = sshbuf_get_bignum1(copy, pub->rsa->n)) != 0 || + (r = sshbuf_get_bignum1(copy, pub->rsa->e)) != 0) + goto out; + + /* Finally, the comment */ + if ((r = sshbuf_get_string(copy, (u_char**)commentp, NULL)) != 0) + goto out; + + /* The encrypted private part is not parsed by this function. */ + + r = 0; + if (keyp != NULL) + *keyp = pub; + else + sshkey_free(pub); + pub = NULL; + + out: + if (copy != NULL) + sshbuf_free(copy); + if (pub != NULL) + sshkey_free(pub); + return r; +} + +static int +sshkey_parse_private_rsa1(struct sshbuf *blob, const char *passphrase, + struct sshkey **keyp, char **commentp) +{ + int r; + u_int16_t check1, check2; + u_int8_t cipher_type; + struct sshbuf *decrypted = NULL, *copy = NULL; + u_char *cp; + char *comment = NULL; + struct sshcipher_ctx ciphercontext; + const struct sshcipher *cipher; + struct sshkey *prv = NULL; + + *keyp = NULL; + if (commentp != NULL) + *commentp = NULL; + + /* Check that it is at least big enough to contain the ID string. */ + if (sshbuf_len(blob) < sizeof(LEGACY_BEGIN)) + return SSH_ERR_INVALID_FORMAT; + + /* + * Make sure it begins with the id string. Consume the id string + * from the buffer. + */ + if (memcmp(sshbuf_ptr(blob), LEGACY_BEGIN, sizeof(LEGACY_BEGIN)) != 0) + return SSH_ERR_INVALID_FORMAT; + + if ((prv = sshkey_new_private(KEY_RSA1)) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((copy = sshbuf_fromb(blob)) == NULL || + (decrypted = sshbuf_new()) == NULL) { + r = SSH_ERR_ALLOC_FAIL; + goto out; + } + if ((r = sshbuf_consume(copy, sizeof(LEGACY_BEGIN))) != 0) + goto out; + + /* Read cipher type. */ + if ((r = sshbuf_get_u8(copy, &cipher_type)) != 0 || + (r = sshbuf_get_u32(copy, NULL)) != 0) /* reserved */ + goto out; + + /* Read the public key and comment from the buffer. */ + if ((r = sshbuf_get_u32(copy, NULL)) != 0 || /* key bits */ + (r = sshbuf_get_bignum1(copy, prv->rsa->n)) != 0 || + (r = sshbuf_get_bignum1(copy, prv->rsa->e)) != 0 || + (r = sshbuf_get_cstring(copy, &comment, NULL)) != 0) + goto out; + + /* Check that it is a supported cipher. */ + cipher = cipher_by_number(cipher_type); + if (cipher == NULL) { + r = SSH_ERR_KEY_UNKNOWN_CIPHER; + goto out; + } + /* Initialize space for decrypted data. */ + if ((r = sshbuf_reserve(decrypted, sshbuf_len(copy), &cp)) != 0) + goto out; + + /* Rest of the buffer is encrypted. Decrypt it using the passphrase. */ + if ((r = cipher_set_key_string(&ciphercontext, cipher, passphrase, + CIPHER_DECRYPT)) != 0) + goto out; + if ((r = cipher_crypt(&ciphercontext, 0, cp, + sshbuf_ptr(copy), sshbuf_len(copy), 0, 0)) != 0) { + cipher_cleanup(&ciphercontext); + goto out; + } + if ((r = cipher_cleanup(&ciphercontext)) != 0) + goto out; + + if ((r = sshbuf_get_u16(decrypted, &check1)) != 0 || + (r = sshbuf_get_u16(decrypted, &check2)) != 0) + goto out; + if (check1 != check2) { + r = SSH_ERR_KEY_WRONG_PASSPHRASE; + goto out; + } + + /* Read the rest of the private key. */ + if ((r = sshbuf_get_bignum1(decrypted, prv->rsa->d)) != 0 || + (r = sshbuf_get_bignum1(decrypted, prv->rsa->iqmp)) != 0 || + (r = sshbuf_get_bignum1(decrypted, prv->rsa->q)) != 0 || + (r = sshbuf_get_bignum1(decrypted, prv->rsa->p)) != 0) + goto out; + + /* calculate p-1 and q-1 */ + if ((r = rsa_generate_additional_parameters(prv->rsa)) != 0) + goto out; + + /* enable blinding */ + if (RSA_blinding_on(prv->rsa, NULL) != 1) { + r = SSH_ERR_LIBCRYPTO_ERROR; + goto out; + } + r = 0; + *keyp = prv; + prv = NULL; + if (commentp != NULL) { + *commentp = comment; + comment = NULL; + } + out: + explicit_bzero(&ciphercontext, sizeof(ciphercontext)); + if (comment != NULL) + free(comment); + if (prv != NULL) + sshkey_free(prv); + if (copy != NULL) + sshbuf_free(copy); + if (decrypted != NULL) + sshbuf_free(decrypted); + return r; +} +#endif /* WITH_SSH1 */ + +#ifdef WITH_OPENSSL +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; + + *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; + } + + if ((pk = PEM_read_bio_PrivateKey(bio, NULL, NULL, + (char *)passphrase)) == NULL) { + r = SSH_ERR_KEY_WRONG_PASSPHRASE; + 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; + } + } 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; + *keyp = prv; + prv = NULL; + out: + BIO_free(bio); + if (pk != NULL) + EVP_PKEY_free(pk); + if (prv != NULL) + 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; + + *keyp = NULL; + if (commentp != NULL) + *commentp = NULL; + + switch (type) { +#ifdef WITH_SSH1 + case KEY_RSA1: + return sshkey_parse_private_rsa1(blob, passphrase, + keyp, commentp); +#endif /* WITH_SSH1 */ +#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: + if ((r = sshkey_parse_private2(blob, type, passphrase, keyp, + commentp)) == 0) + return 0; +#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, + const char *filename, struct sshkey **keyp, char **commentp) +{ + int r; + + if (keyp != NULL) + *keyp = NULL; + if (commentp != NULL) + *commentp = NULL; + +#ifdef WITH_SSH1 + /* it's a SSH v1 key if the public key part is readable */ + if ((r = sshkey_parse_public_rsa1_fileblob(buffer, NULL, NULL)) == 0) { + return sshkey_parse_private_fileblob_type(buffer, KEY_RSA1, + passphrase, keyp, commentp); + } +#endif /* WITH_SSH1 */ + if ((r = sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC, + passphrase, keyp, commentp)) == 0) + return 0; + return r; +} |
