/* $OpenBSD: sshkey.c,v 1.84 2019/10/09 00:04:42 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 #include #ifdef WITH_OPENSSL #include #include #include #endif #include "crypto_api.h" #include #include #include #include #include #include #ifdef HAVE_UTIL_H #include #endif /* HAVE_UTIL_H */ #include "ssh2.h" #include "ssherr.h" #include "misc.h" #include "sshbuf.h" #include "cipher.h" #include "digest.h" #define SSHKEY_INTERNAL #include "sshkey.h" #include "match.h" #ifdef WITH_XMSS #include "sshkey-xmss.h" #include "xmss_fast.h" #endif #ifdef WINDOWS #include #endif #include "openbsd-compat/openssl-compat.h" /* openssh private key file format */ #define MARK_BEGIN "-----BEGIN OPENSSH PRIVATE KEY-----\n" #define MARK_END "-----END OPENSSH PRIVATE KEY-----\n" #define MARK_BEGIN_LEN (sizeof(MARK_BEGIN) - 1) #define MARK_END_LEN (sizeof(MARK_END) - 1) #ifdef SUPPORT_CRLF #define MARK_BEGIN_CRLF "-----BEGIN OPENSSH PRIVATE KEY-----\r\n" #define MARK_END_CRLF "-----END OPENSSH PRIVATE KEY-----\r\n" #define MARK_BEGIN_LEN_CRLF (sizeof(MARK_BEGIN_CRLF) - 1) #define MARK_END_LEN_CRLF (sizeof(MARK_END_CRLF) - 1) #endif // SUPPORT_CRLF #define KDFNAME "bcrypt" #define AUTH_MAGIC "openssh-key-v1" #define SALT_LEN 16 #define DEFAULT_CIPHERNAME "aes256-ctr" #define DEFAULT_ROUNDS 16 /* Version identification string for SSH v1 identity files. */ #define LEGACY_BEGIN "SSH PRIVATE KEY FILE FORMAT 1.1\n" /* * Constants relating to "shielding" support; protection of keys expected * to remain in memory for long durations */ #define SSHKEY_SHIELD_PREKEY_LEN (16 * 1024) #define SSHKEY_SHIELD_CIPHER "aes256-ctr" /* XXX want AES-EME* */ #define SSHKEY_SHIELD_PREKEY_HASH SSH_DIGEST_SHA512 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, enum sshkey_serialize_rep); static int sshkey_from_blob_internal(struct sshbuf *buf, struct sshkey **keyp, int allow_cert); /* Supported key types */ struct keytype { const char *name; const char *shortname; const char *sigalg; int type; int nid; int cert; int sigonly; }; static const struct keytype keytypes[] = { { "ssh-ed25519", "ED25519", NULL, KEY_ED25519, 0, 0, 0 }, { "ssh-ed25519-cert-v01@openssh.com", "ED25519-CERT", NULL, KEY_ED25519_CERT, 0, 1, 0 }, #ifdef WITH_XMSS { "ssh-xmss@openssh.com", "XMSS", NULL, KEY_XMSS, 0, 0, 0 }, { "ssh-xmss-cert-v01@openssh.com", "XMSS-CERT", NULL, KEY_XMSS_CERT, 0, 1, 0 }, #endif /* WITH_XMSS */ #ifdef WITH_OPENSSL { "ssh-rsa", "RSA", NULL, KEY_RSA, 0, 0, 0 }, { "rsa-sha2-256", "RSA", NULL, KEY_RSA, 0, 0, 1 }, { "rsa-sha2-512", "RSA", NULL, KEY_RSA, 0, 0, 1 }, { "ssh-dss", "DSA", NULL, KEY_DSA, 0, 0, 0 }, # ifdef OPENSSL_HAS_ECC { "ecdsa-sha2-nistp256", "ECDSA", NULL, KEY_ECDSA, NID_X9_62_prime256v1, 0, 0 }, { "ecdsa-sha2-nistp384", "ECDSA", NULL, KEY_ECDSA, NID_secp384r1, 0, 0 }, # ifdef OPENSSL_HAS_NISTP521 { "ecdsa-sha2-nistp521", "ECDSA", NULL, KEY_ECDSA, NID_secp521r1, 0, 0 }, # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ { "ssh-rsa-cert-v01@openssh.com", "RSA-CERT", NULL, KEY_RSA_CERT, 0, 1, 0 }, { "rsa-sha2-256-cert-v01@openssh.com", "RSA-CERT", "rsa-sha2-256", KEY_RSA_CERT, 0, 1, 1 }, { "rsa-sha2-512-cert-v01@openssh.com", "RSA-CERT", "rsa-sha2-512", KEY_RSA_CERT, 0, 1, 1 }, { "ssh-dss-cert-v01@openssh.com", "DSA-CERT", NULL, KEY_DSA_CERT, 0, 1, 0 }, # ifdef OPENSSL_HAS_ECC { "ecdsa-sha2-nistp256-cert-v01@openssh.com", "ECDSA-CERT", NULL, KEY_ECDSA_CERT, NID_X9_62_prime256v1, 1, 0 }, { "ecdsa-sha2-nistp384-cert-v01@openssh.com", "ECDSA-CERT", NULL, KEY_ECDSA_CERT, NID_secp384r1, 1, 0 }, # ifdef OPENSSL_HAS_NISTP521 { "ecdsa-sha2-nistp521-cert-v01@openssh.com", "ECDSA-CERT", NULL, KEY_ECDSA_CERT, NID_secp521r1, 1, 0 }, # endif /* OPENSSL_HAS_NISTP521 */ # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ { NULL, NULL, NULL, -1, -1, 0, 0 } }; const char * sshkey_type(const struct sshkey *k) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->type == k->type) return kt->shortname; } return "unknown"; } static const char * sshkey_ssh_name_from_type_nid(int type, int nid) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->type == type && (kt->nid == 0 || kt->nid == nid)) return kt->name; } return "ssh-unknown"; } int sshkey_type_is_cert(int type) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->type == type) return kt->cert; } return 0; } const char * sshkey_ssh_name(const struct sshkey *k) { return sshkey_ssh_name_from_type_nid(k->type, k->ecdsa_nid); } const char * sshkey_ssh_name_plain(const struct sshkey *k) { return sshkey_ssh_name_from_type_nid(sshkey_type_plain(k->type), k->ecdsa_nid); } int sshkey_type_from_name(const char *name) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { /* Only allow shortname matches for plain key types */ if ((kt->name != NULL && strcmp(name, kt->name) == 0) || (!kt->cert && strcasecmp(kt->shortname, name) == 0)) return kt->type; } return KEY_UNSPEC; } int sshkey_ecdsa_nid_from_name(const char *name) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->type != KEY_ECDSA && kt->type != KEY_ECDSA_CERT) continue; if (kt->name != NULL && strcmp(name, kt->name) == 0) return kt->nid; } return -1; } char * sshkey_alg_list(int certs_only, int plain_only, int include_sigonly, char sep) { char *tmp, *ret = NULL; size_t nlen, rlen = 0; const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->name == NULL) continue; if (!include_sigonly && kt->sigonly) continue; if ((certs_only && !kt->cert) || (plain_only && kt->cert)) continue; if (ret != NULL) ret[rlen++] = sep; nlen = strlen(kt->name); if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) { free(ret); return NULL; } ret = tmp; memcpy(ret + rlen, kt->name, nlen + 1); rlen += nlen; } return ret; } int sshkey_names_valid2(const char *names, int allow_wildcard) { char *s, *cp, *p; const struct keytype *kt; int type; if (names == NULL || strcmp(names, "") == 0) return 0; if ((s = cp = strdup(names)) == NULL) return 0; for ((p = strsep(&cp, ",")); p && *p != '\0'; (p = strsep(&cp, ","))) { type = sshkey_type_from_name(p); if (type == KEY_UNSPEC) { if (allow_wildcard) { /* * Try matching key types against the string. * If any has a positive or negative match then * the component is accepted. */ for (kt = keytypes; kt->type != -1; kt++) { if (match_pattern_list(kt->name, p, 0) != 0) break; } if (kt->type != -1) continue; } free(s); return 0; } } free(s); return 1; } u_int sshkey_size(const struct sshkey *k) { #ifdef WITH_OPENSSL const BIGNUM *rsa_n, *dsa_p; #endif /* WITH_OPENSSL */ switch (k->type) { #ifdef WITH_OPENSSL case KEY_RSA: case KEY_RSA_CERT: if (k->rsa == NULL) return 0; RSA_get0_key(k->rsa, &rsa_n, NULL, NULL); return BN_num_bits(rsa_n); case KEY_DSA: case KEY_DSA_CERT: if (k->dsa == NULL) return 0; DSA_get0_pqg(k->dsa, &dsa_p, NULL, NULL); return BN_num_bits(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: case KEY_XMSS: case KEY_XMSS_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: case KEY_XMSS: 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; case KEY_XMSS_CERT: return KEY_XMSS; default: return type; } } #ifdef WITH_OPENSSL /* XXX: these are really begging for a table-driven approach */ int sshkey_curve_name_to_nid(const char *name) { if (strcmp(name, "nistp256") == 0) return NID_X9_62_prime256v1; else if (strcmp(name, "nistp384") == 0) return NID_secp384r1; # ifdef OPENSSL_HAS_NISTP521 else if (strcmp(name, "nistp521") == 0) return NID_secp521r1; # endif /* OPENSSL_HAS_NISTP521 */ else return -1; } u_int sshkey_curve_nid_to_bits(int nid) { switch (nid) { case NID_X9_62_prime256v1: return 256; case NID_secp384r1: return 384; # ifdef OPENSSL_HAS_NISTP521 case NID_secp521r1: return 521; # endif /* OPENSSL_HAS_NISTP521 */ default: return 0; } } int sshkey_ecdsa_bits_to_nid(int bits) { switch (bits) { case 256: return NID_X9_62_prime256v1; case 384: return NID_secp384r1; # ifdef OPENSSL_HAS_NISTP521 case 521: return NID_secp521r1; # endif /* OPENSSL_HAS_NISTP521 */ default: return -1; } } const char * sshkey_curve_nid_to_name(int nid) { switch (nid) { case NID_X9_62_prime256v1: return "nistp256"; case NID_secp384r1: return "nistp384"; # ifdef OPENSSL_HAS_NISTP521 case NID_secp521r1: return "nistp521"; # endif /* OPENSSL_HAS_NISTP521 */ default: return NULL; } } int sshkey_ec_nid_to_hash_alg(int nid) { int kbits = sshkey_curve_nid_to_bits(nid); if (kbits <= 0) return -1; /* RFC5656 section 6.2.1 */ if (kbits <= 256) return SSH_DIGEST_SHA256; else if (kbits <= 384) return SSH_DIGEST_SHA384; else return SSH_DIGEST_SHA512; } #endif /* WITH_OPENSSL */ static void cert_free(struct sshkey_cert *cert) { u_int i; if (cert == NULL) return; sshbuf_free(cert->certblob); sshbuf_free(cert->critical); sshbuf_free(cert->extensions); free(cert->key_id); for (i = 0; i < cert->nprincipals; i++) free(cert->principals[i]); free(cert->principals); sshkey_free(cert->signature_key); free(cert->signature_type); freezero(cert, sizeof(*cert)); } static struct sshkey_cert * cert_new(void) { struct sshkey_cert *cert; if ((cert = calloc(1, sizeof(*cert))) == NULL) return NULL; if ((cert->certblob = sshbuf_new()) == NULL || (cert->critical = sshbuf_new()) == NULL || (cert->extensions = sshbuf_new()) == NULL) { cert_free(cert); return NULL; } cert->key_id = NULL; cert->principals = NULL; cert->signature_key = NULL; cert->signature_type = NULL; return cert; } struct sshkey * sshkey_new(int type) { struct sshkey *k; #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; k->xmss_sk = NULL; k->xmss_pk = NULL; switch (k->type) { #ifdef WITH_OPENSSL case KEY_RSA: case KEY_RSA_CERT: if ((rsa = RSA_new()) == NULL) { free(k); return NULL; } k->rsa = rsa; break; case KEY_DSA: case KEY_DSA_CERT: if ((dsa = DSA_new()) == NULL) { 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: case KEY_XMSS: case KEY_XMSS_CERT: /* no need to prealloc */ break; case KEY_UNSPEC: break; default: free(k); return NULL; } if (sshkey_is_cert(k)) { if ((k->cert = cert_new()) == NULL) { sshkey_free(k); return NULL; } } return k; } void sshkey_free(struct sshkey *k) { if (k == NULL) return; switch (k->type) { #ifdef WITH_OPENSSL case KEY_RSA: case KEY_RSA_CERT: RSA_free(k->rsa); k->rsa = NULL; break; case KEY_DSA: case KEY_DSA_CERT: DSA_free(k->dsa); k->dsa = NULL; break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA: case KEY_ECDSA_CERT: EC_KEY_free(k->ecdsa); k->ecdsa = NULL; break; # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: freezero(k->ed25519_pk, ED25519_PK_SZ); k->ed25519_pk = NULL; freezero(k->ed25519_sk, ED25519_SK_SZ); k->ed25519_sk = NULL; break; #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: freezero(k->xmss_pk, sshkey_xmss_pklen(k)); k->xmss_pk = NULL; freezero(k->xmss_sk, sshkey_xmss_sklen(k)); k->xmss_sk = NULL; sshkey_xmss_free_state(k); free(k->xmss_name); k->xmss_name = NULL; free(k->xmss_filename); k->xmss_filename = NULL; break; #endif /* WITH_XMSS */ case KEY_UNSPEC: break; default: break; } if (sshkey_is_cert(k)) cert_free(k->cert); freezero(k->shielded_private, k->shielded_len); freezero(k->shield_prekey, k->shield_prekey_len); freezero(k, sizeof(*k)); } static int cert_compare(struct sshkey_cert *a, struct sshkey_cert *b) { if (a == NULL && b == NULL) return 1; if (a == NULL || b == NULL) return 0; if (sshbuf_len(a->certblob) != sshbuf_len(b->certblob)) return 0; if (timingsafe_bcmp(sshbuf_ptr(a->certblob), sshbuf_ptr(b->certblob), sshbuf_len(a->certblob)) != 0) return 0; return 1; } /* * 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) const BIGNUM *rsa_e_a, *rsa_n_a; const BIGNUM *rsa_e_b, *rsa_n_b; const BIGNUM *dsa_p_a, *dsa_q_a, *dsa_g_a, *dsa_pub_key_a; const BIGNUM *dsa_p_b, *dsa_q_b, *dsa_g_b, *dsa_pub_key_b; # if defined(OPENSSL_HAS_ECC) BN_CTX *bnctx; # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ if (a == NULL || b == NULL || sshkey_type_plain(a->type) != sshkey_type_plain(b->type)) return 0; switch (a->type) { #ifdef WITH_OPENSSL case KEY_RSA_CERT: case KEY_RSA: if (a->rsa == NULL || b->rsa == NULL) return 0; RSA_get0_key(a->rsa, &rsa_n_a, &rsa_e_a, NULL); RSA_get0_key(b->rsa, &rsa_n_b, &rsa_e_b, NULL); return BN_cmp(rsa_e_a, rsa_e_b) == 0 && BN_cmp(rsa_n_a, rsa_n_b) == 0; case KEY_DSA_CERT: case KEY_DSA: if (a->dsa == NULL || b->dsa == NULL) return 0; DSA_get0_pqg(a->dsa, &dsa_p_a, &dsa_q_a, &dsa_g_a); DSA_get0_pqg(b->dsa, &dsa_p_b, &dsa_q_b, &dsa_g_b); DSA_get0_key(a->dsa, &dsa_pub_key_a, NULL); DSA_get0_key(b->dsa, &dsa_pub_key_b, NULL); return BN_cmp(dsa_p_a, dsa_p_b) == 0 && BN_cmp(dsa_q_a, dsa_q_b) == 0 && BN_cmp(dsa_g_a, dsa_g_b) == 0 && BN_cmp(dsa_pub_key_a, dsa_pub_key_b) == 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; #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: return a->xmss_pk != NULL && b->xmss_pk != NULL && sshkey_xmss_pklen(a) == sshkey_xmss_pklen(b) && memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) == 0; #endif /* WITH_XMSS */ 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, enum sshkey_serialize_rep opts) { int type, ret = SSH_ERR_INTERNAL_ERROR; const char *typename; #ifdef WITH_OPENSSL const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; #endif /* WITH_OPENSSL */ 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: #ifdef WITH_XMSS case KEY_XMSS_CERT: #endif /* WITH_XMSS */ /* 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; DSA_get0_pqg(key->dsa, &dsa_p, &dsa_q, &dsa_g); DSA_get0_key(key->dsa, &dsa_pub_key, NULL); if ((ret = sshbuf_put_cstring(b, typename)) != 0 || (ret = sshbuf_put_bignum2(b, dsa_p)) != 0 || (ret = sshbuf_put_bignum2(b, dsa_q)) != 0 || (ret = sshbuf_put_bignum2(b, dsa_g)) != 0 || (ret = sshbuf_put_bignum2(b, 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; RSA_get0_key(key->rsa, &rsa_n, &rsa_e, NULL); if ((ret = sshbuf_put_cstring(b, typename)) != 0 || (ret = sshbuf_put_bignum2(b, rsa_e)) != 0 || (ret = sshbuf_put_bignum2(b, 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; #ifdef WITH_XMSS case KEY_XMSS: if (key->xmss_name == NULL || key->xmss_pk == NULL || sshkey_xmss_pklen(key) == 0) return SSH_ERR_INVALID_ARGUMENT; if ((ret = sshbuf_put_cstring(b, typename)) != 0 || (ret = sshbuf_put_cstring(b, key->xmss_name)) != 0 || (ret = sshbuf_put_string(b, key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || (ret = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0) return ret; break; #endif /* WITH_XMSS */ 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, SSHKEY_SERIALIZE_DEFAULT); } int sshkey_puts_opts(const struct sshkey *key, struct sshbuf *b, enum sshkey_serialize_rep opts) { struct sshbuf *tmp; int r; if ((tmp = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; r = to_blob_buf(key, tmp, 0, opts); if (r == 0) r = sshbuf_put_stringb(b, tmp); sshbuf_free(tmp); return r; } int sshkey_puts(const struct sshkey *key, struct sshbuf *b) { return sshkey_puts_opts(key, b, SSHKEY_SERIALIZE_DEFAULT); } int sshkey_putb_plain(const struct sshkey *key, struct sshbuf *b) { return to_blob_buf(key, b, 1, SSHKEY_SERIALIZE_DEFAULT); } static int to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp, int force_plain, enum sshkey_serialize_rep opts) { int ret = SSH_ERR_INTERNAL_ERROR; size_t len; struct sshbuf *b = NULL; if (lenp != NULL) *lenp = 0; if (blobp != NULL) *blobp = NULL; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((ret = to_blob_buf(key, b, force_plain, opts)) != 0) goto out; len = sshbuf_len(b); if (lenp != NULL) *lenp = len; if (blobp != NULL) { if ((*blobp = malloc(len)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(*blobp, sshbuf_ptr(b), len); } ret = 0; out: sshbuf_free(b); return ret; } int sshkey_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) { return to_blob(key, blobp, lenp, 0, SSHKEY_SERIALIZE_DEFAULT); } int sshkey_plain_to_blob(const struct sshkey *key, u_char **blobp, size_t *lenp) { return to_blob(key, blobp, lenp, 1, SSHKEY_SERIALIZE_DEFAULT); } int sshkey_fingerprint_raw(const struct sshkey *k, int dgst_alg, u_char **retp, size_t *lenp) { u_char *blob = NULL, *ret = NULL; size_t blob_len = 0; int r = SSH_ERR_INTERNAL_ERROR; if (retp != NULL) *retp = NULL; if (lenp != NULL) *lenp = 0; if (ssh_digest_bytes(dgst_alg) == 0) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((r = to_blob(k, &blob, &blob_len, 1, SSHKEY_SERIALIZE_DEFAULT)) != 0) goto out; if ((ret = calloc(1, SSH_DIGEST_MAX_LENGTH)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = ssh_digest_memory(dgst_alg, blob, blob_len, ret, SSH_DIGEST_MAX_LENGTH)) != 0) goto out; /* success */ if (retp != NULL) { *retp = ret; ret = NULL; } if (lenp != NULL) *lenp = ssh_digest_bytes(dgst_alg); r = 0; out: free(ret); if (blob != NULL) { 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; if (dgst_raw_len > 65536 || (ret = calloc(1, rlen)) == NULL) return NULL; strlcpy(ret, alg, rlen); strlcat(ret, ":", rlen); if (dgst_raw_len == 0) return ret; if (b64_ntop(dgst_raw, dgst_raw_len, ret + plen, rlen - plen) == -1) { freezero(ret, rlen); return NULL; } /* Trim padding characters from end */ ret[strcspn(ret, "=")] = '\0'; return ret; } static char * fingerprint_hex(const char *alg, u_char *dgst_raw, size_t dgst_raw_len) { char *retval, hex[5]; size_t i, rlen = dgst_raw_len * 3 + strlen(alg) + 2; if (dgst_raw_len > 65536 || (retval = calloc(1, rlen)) == NULL) return NULL; strlcpy(retval, alg, rlen); strlcat(retval, ":", rlen); for (i = 0; i < dgst_raw_len; i++) { snprintf(hex, sizeof(hex), "%s%02x", i > 0 ? ":" : "", dgst_raw[i]); strlcat(retval, hex, rlen); } return retval; } static char * fingerprint_bubblebabble(u_char *dgst_raw, size_t dgst_raw_len) { char vowels[] = { 'a', 'e', 'i', 'o', 'u', 'y' }; char consonants[] = { 'b', 'c', 'd', 'f', 'g', 'h', 'k', 'l', 'm', 'n', 'p', 'r', 's', 't', 'v', 'z', 'x' }; u_int i, j = 0, rounds, seed = 1; char *retval; rounds = (dgst_raw_len / 2) + 1; if ((retval = calloc(rounds, 6)) == NULL) return NULL; retval[j++] = 'x'; for (i = 0; i < rounds; i++) { u_int idx0, idx1, idx2, idx3, idx4; if ((i + 1 < rounds) || (dgst_raw_len % 2 != 0)) { idx0 = (((((u_int)(dgst_raw[2 * i])) >> 6) & 3) + seed) % 6; idx1 = (((u_int)(dgst_raw[2 * i])) >> 2) & 15; idx2 = ((((u_int)(dgst_raw[2 * i])) & 3) + (seed / 6)) % 6; retval[j++] = vowels[idx0]; retval[j++] = consonants[idx1]; retval[j++] = vowels[idx2]; if ((i + 1) < rounds) { idx3 = (((u_int)(dgst_raw[(2 * i) + 1])) >> 4) & 15; idx4 = (((u_int)(dgst_raw[(2 * i) + 1]))) & 15; retval[j++] = consonants[idx3]; retval[j++] = '-'; retval[j++] = consonants[idx4]; seed = ((seed * 5) + ((((u_int)(dgst_raw[2 * i])) * 7) + ((u_int)(dgst_raw[(2 * i) + 1])))) % 36; } } else { idx0 = seed % 6; idx1 = 16; idx2 = seed / 6; retval[j++] = vowels[idx0]; retval[j++] = consonants[idx1]; retval[j++] = vowels[idx2]; } } retval[j++] = 'x'; retval[j++] = '\0'; return retval; } /* * Draw an ASCII-Art representing the fingerprint so human brain can * profit from its built-in pattern recognition ability. * This technique is called "random art" and can be found in some * scientific publications like this original paper: * * "Hash Visualization: a New Technique to improve Real-World Security", * Perrig A. and Song D., 1999, International Workshop on Cryptographic * Techniques and E-Commerce (CrypTEC '99) * sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf * * The subject came up in a talk by Dan Kaminsky, too. * * If you see the picture is different, the key is different. * If the picture looks the same, you still know nothing. * * The algorithm used here is a worm crawling over a discrete plane, * leaving a trace (augmenting the field) everywhere it goes. * Movement is taken from dgst_raw 2bit-wise. Bumping into walls * makes the respective movement vector be ignored for this turn. * Graphs are not unambiguous, because circles in graphs can be * walked in either direction. */ /* * Field sizes for the random art. Have to be odd, so the starting point * can be in the exact middle of the picture, and FLDBASE should be >=8 . * Else pictures would be too dense, and drawing the frame would * fail, too, because the key type would not fit in anymore. */ #define FLDBASE 8 #define FLDSIZE_Y (FLDBASE + 1) #define FLDSIZE_X (FLDBASE * 2 + 1) static char * fingerprint_randomart(const char *alg, u_char *dgst_raw, size_t dgst_raw_len, const struct sshkey *k) { /* * Chars to be used after each other every time the worm * intersects with itself. Matter of taste. */ char *augmentation_string = " .o+=*BOX@%&#/^SE"; char *retval, *p, title[FLDSIZE_X], hash[FLDSIZE_X]; u_char field[FLDSIZE_X][FLDSIZE_Y]; size_t i, tlen, hlen; u_int b; int x, y, r; size_t len = strlen(augmentation_string) - 1; if ((retval = calloc((FLDSIZE_X + 3), (FLDSIZE_Y + 2))) == NULL) return NULL; /* initialize field */ memset(field, 0, FLDSIZE_X * FLDSIZE_Y * sizeof(char)); x = FLDSIZE_X / 2; y = FLDSIZE_Y / 2; /* process raw key */ for (i = 0; i < dgst_raw_len; i++) { int input; /* each byte conveys four 2-bit move commands */ input = dgst_raw[i]; for (b = 0; b < 4; b++) { /* evaluate 2 bit, rest is shifted later */ x += (input & 0x1) ? 1 : -1; y += (input & 0x2) ? 1 : -1; /* assure we are still in bounds */ x = MAXIMUM(x, 0); y = MAXIMUM(y, 0); x = MINIMUM(x, FLDSIZE_X - 1); y = MINIMUM(y, FLDSIZE_Y - 1); /* augment the field */ if (field[x][y] < len - 2) field[x][y]++; input = input >> 2; } } /* mark starting point and end point*/ field[FLDSIZE_X / 2][FLDSIZE_Y / 2] = len - 1; field[x][y] = len; /* assemble title */ r = snprintf(title, sizeof(title), "[%s %u]", sshkey_type(k), sshkey_size(k)); /* If [type size] won't fit, then try [type]; fits "[ED25519-CERT]" */ if (r < 0 || r > (int)sizeof(title)) r = snprintf(title, sizeof(title), "[%s]", sshkey_type(k)); tlen = (r <= 0) ? 0 : strlen(title); /* assemble hash ID. */ r = snprintf(hash, sizeof(hash), "[%s]", alg); hlen = (r <= 0) ? 0 : strlen(hash); /* output upper border */ p = retval; *p++ = '+'; for (i = 0; i < (FLDSIZE_X - tlen) / 2; i++) *p++ = '-'; memcpy(p, title, tlen); p += tlen; for (i += tlen; i < FLDSIZE_X; i++) *p++ = '-'; *p++ = '+'; *p++ = '\n'; /* output content */ for (y = 0; y < FLDSIZE_Y; y++) { *p++ = '|'; for (x = 0; x < FLDSIZE_X; x++) *p++ = augmentation_string[MINIMUM(field[x][y], len)]; *p++ = '|'; *p++ = '\n'; } /* output lower border */ *p++ = '+'; for (i = 0; i < (FLDSIZE_X - hlen) / 2; i++) *p++ = '-'; memcpy(p, hash, hlen); p += hlen; for (i += hlen; i < FLDSIZE_X; i++) *p++ = '-'; *p++ = '+'; return retval; } char * sshkey_fingerprint(const struct sshkey *k, int dgst_alg, enum sshkey_fp_rep dgst_rep) { char *retval = NULL; u_char *dgst_raw; size_t dgst_raw_len; if (sshkey_fingerprint_raw(k, dgst_alg, &dgst_raw, &dgst_raw_len) != 0) return NULL; switch (dgst_rep) { case SSH_FP_DEFAULT: if (dgst_alg == SSH_DIGEST_MD5) { retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), dgst_raw, dgst_raw_len); } else { retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), dgst_raw, dgst_raw_len); } break; case SSH_FP_HEX: retval = fingerprint_hex(ssh_digest_alg_name(dgst_alg), dgst_raw, dgst_raw_len); break; case SSH_FP_BASE64: retval = fingerprint_b64(ssh_digest_alg_name(dgst_alg), dgst_raw, dgst_raw_len); break; case SSH_FP_BUBBLEBABBLE: retval = fingerprint_bubblebabble(dgst_raw, dgst_raw_len); break; case SSH_FP_RANDOMART: retval = fingerprint_randomart(ssh_digest_alg_name(dgst_alg), dgst_raw, dgst_raw_len, k); break; default: explicit_bzero(dgst_raw, dgst_raw_len); free(dgst_raw); return NULL; } explicit_bzero(dgst_raw, dgst_raw_len); free(dgst_raw); return retval; } static int peek_type_nid(const char *s, size_t l, int *nid) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (kt->name == NULL || strlen(kt->name) != l) continue; if (memcmp(s, kt->name, l) == 0) { *nid = -1; if (kt->type == KEY_ECDSA || kt->type == KEY_ECDSA_CERT) *nid = kt->nid; return kt->type; } } return KEY_UNSPEC; } /* XXX this can now be made const char * */ int sshkey_read(struct sshkey *ret, char **cpp) { struct sshkey *k; char *cp, *blobcopy; size_t space; int r, type, curve_nid = -1; struct sshbuf *blob; if (ret == NULL) return SSH_ERR_INVALID_ARGUMENT; switch (ret->type) { case KEY_UNSPEC: case KEY_RSA: case KEY_DSA: case KEY_ECDSA: case KEY_ED25519: case KEY_DSA_CERT: case KEY_ECDSA_CERT: case KEY_RSA_CERT: case KEY_ED25519_CERT: #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: #endif /* WITH_XMSS */ break; /* ok */ default: return SSH_ERR_INVALID_ARGUMENT; } /* Decode type */ cp = *cpp; space = strcspn(cp, " \t"); if (space == strlen(cp)) return SSH_ERR_INVALID_FORMAT; if ((type = peek_type_nid(cp, space, &curve_nid)) == KEY_UNSPEC) return SSH_ERR_INVALID_FORMAT; /* skip whitespace */ for (cp += space; *cp == ' ' || *cp == '\t'; cp++) ; if (*cp == '\0') return SSH_ERR_INVALID_FORMAT; if (ret->type != KEY_UNSPEC && ret->type != type) return SSH_ERR_KEY_TYPE_MISMATCH; if ((blob = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; /* find end of keyblob and decode */ space = strcspn(cp, " \t"); if ((blobcopy = strndup(cp, space)) == NULL) { sshbuf_free(blob); return SSH_ERR_ALLOC_FAIL; } if ((r = sshbuf_b64tod(blob, blobcopy)) != 0) { free(blobcopy); sshbuf_free(blob); return r; } free(blobcopy); if ((r = sshkey_fromb(blob, &k)) != 0) { sshbuf_free(blob); return r; } sshbuf_free(blob); /* skip whitespace and leave cp at start of comment */ for (cp += space; *cp == ' ' || *cp == '\t'; cp++) ; /* ensure type of blob matches type at start of line */ if (k->type != type) { sshkey_free(k); return SSH_ERR_KEY_TYPE_MISMATCH; } if (sshkey_type_plain(type) == KEY_ECDSA && curve_nid != k->ecdsa_nid) { sshkey_free(k); return SSH_ERR_EC_CURVE_MISMATCH; } /* Fill in ret from parsed key */ ret->type = type; if (sshkey_is_cert(ret)) { if (!sshkey_is_cert(k)) { sshkey_free(k); return SSH_ERR_EXPECTED_CERT; } if (ret->cert != NULL) cert_free(ret->cert); ret->cert = k->cert; k->cert = NULL; } switch (sshkey_type_plain(ret->type)) { #ifdef WITH_OPENSSL case KEY_RSA: RSA_free(ret->rsa); ret->rsa = k->rsa; k->rsa = NULL; #ifdef DEBUG_PK RSA_print_fp(stderr, ret->rsa, 8); #endif break; case KEY_DSA: DSA_free(ret->dsa); ret->dsa = k->dsa; k->dsa = NULL; #ifdef DEBUG_PK DSA_print_fp(stderr, ret->dsa, 8); #endif break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA: EC_KEY_free(ret->ecdsa); ret->ecdsa = k->ecdsa; ret->ecdsa_nid = k->ecdsa_nid; k->ecdsa = NULL; k->ecdsa_nid = -1; #ifdef DEBUG_PK sshkey_dump_ec_key(ret->ecdsa); #endif break; # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ case KEY_ED25519: freezero(ret->ed25519_pk, ED25519_PK_SZ); ret->ed25519_pk = k->ed25519_pk; k->ed25519_pk = NULL; #ifdef DEBUG_PK /* XXX */ #endif break; #ifdef WITH_XMSS case KEY_XMSS: free(ret->xmss_pk); ret->xmss_pk = k->xmss_pk; k->xmss_pk = NULL; free(ret->xmss_state); ret->xmss_state = k->xmss_state; k->xmss_state = NULL; free(ret->xmss_name); ret->xmss_name = k->xmss_name; k->xmss_name = NULL; free(ret->xmss_filename); ret->xmss_filename = k->xmss_filename; k->xmss_filename = NULL; #ifdef DEBUG_PK /* XXX */ #endif break; #endif /* WITH_XMSS */ default: sshkey_free(k); return SSH_ERR_INTERNAL_ERROR; } sshkey_free(k); /* success */ *cpp = cp; return 0; } int sshkey_to_base64(const struct sshkey *key, char **b64p) { int r = SSH_ERR_INTERNAL_ERROR; struct sshbuf *b = NULL; char *uu = NULL; if (b64p != NULL) *b64p = NULL; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshkey_putb(key, b)) != 0) goto out; if ((uu = sshbuf_dtob64_string(b, 0)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } /* Success */ if (b64p != NULL) { *b64p = uu; uu = NULL; } r = 0; out: sshbuf_free(b); free(uu); return r; } int sshkey_format_text(const struct sshkey *key, struct sshbuf *b) { int r = SSH_ERR_INTERNAL_ERROR; char *uu = NULL; if ((r = sshkey_to_base64(key, &uu)) != 0) goto out; if ((r = sshbuf_putf(b, "%s %s", sshkey_ssh_name(key), uu)) != 0) goto out; r = 0; out: free(uu); return r; } int sshkey_write(const struct sshkey *key, FILE *f) { struct sshbuf *b = NULL; int r = SSH_ERR_INTERNAL_ERROR; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshkey_format_text(key, b)) != 0) goto out; if (fwrite(sshbuf_ptr(b), sshbuf_len(b), 1, f) != 1) { if (feof(f)) errno = EPIPE; r = SSH_ERR_SYSTEM_ERROR; goto out; } /* Success */ r = 0; out: sshbuf_free(b); return r; } const char * sshkey_cert_type(const struct sshkey *k) { switch (k->cert->type) { case SSH2_CERT_TYPE_USER: return "user"; case SSH2_CERT_TYPE_HOST: return "host"; default: return "unknown"; } } #ifdef WITH_OPENSSL static int rsa_generate_private_key(u_int bits, RSA **rsap) { RSA *private = NULL; BIGNUM *f4 = NULL; int ret = SSH_ERR_INTERNAL_ERROR; if (rsap == NULL) return SSH_ERR_INVALID_ARGUMENT; if (bits < SSH_RSA_MINIMUM_MODULUS_SIZE || bits > SSHBUF_MAX_BIGNUM * 8) return SSH_ERR_KEY_LENGTH; *rsap = NULL; if ((private = RSA_new()) == NULL || (f4 = BN_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (!BN_set_word(f4, RSA_F4) || !RSA_generate_key_ex(private, bits, f4, NULL)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } *rsap = private; private = NULL; ret = 0; out: RSA_free(private); BN_free(f4); return ret; } static int dsa_generate_private_key(u_int bits, DSA **dsap) { DSA *private; int ret = SSH_ERR_INTERNAL_ERROR; if (dsap == NULL) return SSH_ERR_INVALID_ARGUMENT; if (bits != 1024) return SSH_ERR_KEY_LENGTH; if ((private = DSA_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } *dsap = NULL; if (!DSA_generate_parameters_ex(private, bits, NULL, 0, NULL, NULL, NULL) || !DSA_generate_key(private)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } *dsap = private; private = NULL; ret = 0; out: DSA_free(private); return ret; } # ifdef OPENSSL_HAS_ECC int sshkey_ecdsa_key_to_nid(EC_KEY *k) { EC_GROUP *eg; int nids[] = { NID_X9_62_prime256v1, NID_secp384r1, # ifdef OPENSSL_HAS_NISTP521 NID_secp521r1, # endif /* OPENSSL_HAS_NISTP521 */ -1 }; int nid; u_int i; BN_CTX *bnctx; const EC_GROUP *g = EC_KEY_get0_group(k); /* * The group may be stored in a ASN.1 encoded private key in one of two * ways: as a "named group", which is reconstituted by ASN.1 object ID * or explicit group parameters encoded into the key blob. Only the * "named group" case sets the group NID for us, but we can figure * it out for the other case by comparing against all the groups that * are supported. */ if ((nid = EC_GROUP_get_curve_name(g)) > 0) return nid; if ((bnctx = BN_CTX_new()) == NULL) return -1; for (i = 0; nids[i] != -1; i++) { if ((eg = EC_GROUP_new_by_curve_name(nids[i])) == NULL) { BN_CTX_free(bnctx); return -1; } if (EC_GROUP_cmp(g, eg, bnctx) == 0) break; EC_GROUP_free(eg); } BN_CTX_free(bnctx); if (nids[i] != -1) { /* Use the group with the NID attached */ EC_GROUP_set_asn1_flag(eg, OPENSSL_EC_NAMED_CURVE); if (EC_KEY_set_group(k, eg) != 1) { EC_GROUP_free(eg); return -1; } } return nids[i]; } static int ecdsa_generate_private_key(u_int bits, int *nid, EC_KEY **ecdsap) { EC_KEY *private; int ret = SSH_ERR_INTERNAL_ERROR; if (nid == NULL || ecdsap == NULL) return SSH_ERR_INVALID_ARGUMENT; if ((*nid = sshkey_ecdsa_bits_to_nid(bits)) == -1) return SSH_ERR_KEY_LENGTH; *ecdsap = NULL; if ((private = EC_KEY_new_by_curve_name(*nid)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (EC_KEY_generate_key(private) != 1) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } EC_KEY_set_asn1_flag(private, OPENSSL_EC_NAMED_CURVE); *ecdsap = private; private = NULL; ret = 0; out: 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_XMSS case KEY_XMSS: ret = sshkey_xmss_generate_private_key(k, bits); break; #endif /* WITH_XMSS */ #ifdef WITH_OPENSSL case KEY_DSA: ret = dsa_generate_private_key(bits, &k->dsa); break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA: ret = ecdsa_generate_private_key(bits, &k->ecdsa_nid, &k->ecdsa); break; # endif /* OPENSSL_HAS_ECC */ case KEY_RSA: ret = rsa_generate_private_key(bits, &k->rsa); break; #endif /* WITH_OPENSSL */ default: ret = SSH_ERR_INVALID_ARGUMENT; } if (ret == 0) { k->type = type; *keyp = k; } else sshkey_free(k); return ret; } int sshkey_cert_copy(const struct sshkey *from_key, struct sshkey *to_key) { u_int i; const struct sshkey_cert *from; struct sshkey_cert *to; int r = SSH_ERR_INTERNAL_ERROR; if (to_key == NULL || (from = from_key->cert) == NULL) return SSH_ERR_INVALID_ARGUMENT; if ((to = cert_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshbuf_putb(to->certblob, from->certblob)) != 0 || (r = sshbuf_putb(to->critical, from->critical)) != 0 || (r = sshbuf_putb(to->extensions, from->extensions)) != 0) goto out; to->serial = from->serial; to->type = from->type; if (from->key_id == NULL) to->key_id = NULL; else if ((to->key_id = strdup(from->key_id)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } to->valid_after = from->valid_after; to->valid_before = from->valid_before; if (from->signature_key == NULL) to->signature_key = NULL; else if ((r = sshkey_from_private(from->signature_key, &to->signature_key)) != 0) goto out; if (from->signature_type != NULL && (to->signature_type = strdup(from->signature_type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (from->nprincipals > SSHKEY_CERT_MAX_PRINCIPALS) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if (from->nprincipals > 0) { if ((to->principals = calloc(from->nprincipals, sizeof(*to->principals))) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } for (i = 0; i < from->nprincipals; i++) { to->principals[i] = strdup(from->principals[i]); if (to->principals[i] == NULL) { to->nprincipals = i; r = SSH_ERR_ALLOC_FAIL; goto out; } } } to->nprincipals = from->nprincipals; /* success */ cert_free(to_key->cert); to_key->cert = to; to = NULL; r = 0; out: cert_free(to); return r; } int sshkey_from_private(const struct sshkey *k, struct sshkey **pkp) { struct sshkey *n = NULL; int r = SSH_ERR_INTERNAL_ERROR; #ifdef WITH_OPENSSL const BIGNUM *rsa_n, *rsa_e; BIGNUM *rsa_n_dup = NULL, *rsa_e_dup = NULL; const BIGNUM *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; BIGNUM *dsa_p_dup = NULL, *dsa_q_dup = NULL, *dsa_g_dup = NULL; BIGNUM *dsa_pub_key_dup = NULL; #endif /* WITH_OPENSSL */ *pkp = NULL; switch (k->type) { #ifdef WITH_OPENSSL case KEY_DSA: case KEY_DSA_CERT: if ((n = sshkey_new(k->type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); DSA_get0_key(k->dsa, &dsa_pub_key, NULL); if ((dsa_p_dup = BN_dup(dsa_p)) == NULL || (dsa_q_dup = BN_dup(dsa_q)) == NULL || (dsa_g_dup = BN_dup(dsa_g)) == NULL || (dsa_pub_key_dup = BN_dup(dsa_pub_key)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (!DSA_set0_pqg(n->dsa, dsa_p_dup, dsa_q_dup, dsa_g_dup)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_p_dup = dsa_q_dup = dsa_g_dup = NULL; /* transferred */ if (!DSA_set0_key(n->dsa, dsa_pub_key_dup, NULL)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_pub_key_dup = NULL; /* transferred */ break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA: case KEY_ECDSA_CERT: if ((n = sshkey_new(k->type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } n->ecdsa_nid = k->ecdsa_nid; n->ecdsa = EC_KEY_new_by_curve_name(k->ecdsa_nid); if (n->ecdsa == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (EC_KEY_set_public_key(n->ecdsa, EC_KEY_get0_public_key(k->ecdsa)) != 1) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } break; # endif /* OPENSSL_HAS_ECC */ case KEY_RSA: case KEY_RSA_CERT: if ((n = sshkey_new(k->type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); if ((rsa_n_dup = BN_dup(rsa_n)) == NULL || (rsa_e_dup = BN_dup(rsa_e)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (!RSA_set0_key(n->rsa, rsa_n_dup, rsa_e_dup, NULL)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_n_dup = rsa_e_dup = NULL; /* transferred */ break; #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: if ((n = sshkey_new(k->type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (k->ed25519_pk != NULL) { if ((n->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(n->ed25519_pk, k->ed25519_pk, ED25519_PK_SZ); } break; #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: if ((n = sshkey_new(k->type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshkey_xmss_init(n, k->xmss_name)) != 0) goto out; if (k->xmss_pk != NULL) { size_t pklen = sshkey_xmss_pklen(k); if (pklen == 0 || sshkey_xmss_pklen(n) != pklen) { r = SSH_ERR_INTERNAL_ERROR; goto out; } if ((n->xmss_pk = malloc(pklen)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } memcpy(n->xmss_pk, k->xmss_pk, pklen); } break; #endif /* WITH_XMSS */ default: r = SSH_ERR_KEY_TYPE_UNKNOWN; goto out; } if (sshkey_is_cert(k) && (r = sshkey_cert_copy(k, n)) != 0) goto out; /* success */ *pkp = n; n = NULL; r = 0; out: sshkey_free(n); #ifdef WITH_OPENSSL BN_clear_free(rsa_n_dup); BN_clear_free(rsa_e_dup); BN_clear_free(dsa_p_dup); BN_clear_free(dsa_q_dup); BN_clear_free(dsa_g_dup); BN_clear_free(dsa_pub_key_dup); #endif return r; } int sshkey_is_shielded(struct sshkey *k) { return k != NULL && k->shielded_private != NULL; } int sshkey_shield_private(struct sshkey *k) { struct sshbuf *prvbuf = NULL; u_char *prekey = NULL, *enc = NULL, keyiv[SSH_DIGEST_MAX_LENGTH]; struct sshcipher_ctx *cctx = NULL; const struct sshcipher *cipher; size_t i, enclen = 0; struct sshkey *kswap = NULL, tmp; int r = SSH_ERR_INTERNAL_ERROR; #ifdef DEBUG_PK fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); #endif if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if (cipher_keylen(cipher) + cipher_ivlen(cipher) > ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { r = SSH_ERR_INTERNAL_ERROR; goto out; } /* Prepare a random pre-key, and from it an ephemeral key */ if ((prekey = malloc(SSHKEY_SHIELD_PREKEY_LEN)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } arc4random_buf(prekey, SSHKEY_SHIELD_PREKEY_LEN); if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, prekey, SSHKEY_SHIELD_PREKEY_LEN, keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) goto out; #ifdef DEBUG_PK fprintf(stderr, "%s: key+iv\n", __func__); sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), stderr); #endif if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 1)) != 0) goto out; /* Serialise and encrypt the private key using the ephemeral key */ if ((prvbuf = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (sshkey_is_shielded(k) && (r = sshkey_unshield_private(k)) != 0) goto out; if ((r = sshkey_private_serialize_opt(k, prvbuf, SSHKEY_SERIALIZE_FULL)) != 0) goto out; /* pad to cipher blocksize */ i = 0; while (sshbuf_len(prvbuf) % cipher_blocksize(cipher)) { if ((r = sshbuf_put_u8(prvbuf, ++i & 0xff)) != 0) goto out; } #ifdef DEBUG_PK fprintf(stderr, "%s: serialised\n", __func__); sshbuf_dump(prvbuf, stderr); #endif /* encrypt */ enclen = sshbuf_len(prvbuf); if ((enc = malloc(enclen)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = cipher_crypt(cctx, 0, enc, sshbuf_ptr(prvbuf), sshbuf_len(prvbuf), 0, 0)) != 0) goto out; #ifdef DEBUG_PK fprintf(stderr, "%s: encrypted\n", __func__); sshbuf_dump_data(enc, enclen, stderr); #endif /* Make a scrubbed, public-only copy of our private key argument */ if ((r = sshkey_from_private(k, &kswap)) != 0) goto out; /* Swap the private key out (it will be destroyed below) */ tmp = *kswap; *kswap = *k; *k = tmp; /* Insert the shielded key into our argument */ k->shielded_private = enc; k->shielded_len = enclen; k->shield_prekey = prekey; k->shield_prekey_len = SSHKEY_SHIELD_PREKEY_LEN; enc = prekey = NULL; /* transferred */ enclen = 0; /* success */ r = 0; out: /* XXX behaviour on error - invalidate original private key? */ cipher_free(cctx); explicit_bzero(keyiv, sizeof(keyiv)); explicit_bzero(&tmp, sizeof(tmp)); freezero(enc, enclen); freezero(prekey, SSHKEY_SHIELD_PREKEY_LEN); sshkey_free(kswap); sshbuf_free(prvbuf); return r; } int sshkey_unshield_private(struct sshkey *k) { struct sshbuf *prvbuf = NULL; u_char pad, *cp, keyiv[SSH_DIGEST_MAX_LENGTH]; struct sshcipher_ctx *cctx = NULL; const struct sshcipher *cipher; size_t i; struct sshkey *kswap = NULL, tmp; int r = SSH_ERR_INTERNAL_ERROR; #ifdef DEBUG_PK fprintf(stderr, "%s: entering for %s\n", __func__, sshkey_ssh_name(k)); #endif if (!sshkey_is_shielded(k)) return 0; /* nothing to do */ if ((cipher = cipher_by_name(SSHKEY_SHIELD_CIPHER)) == NULL) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if (cipher_keylen(cipher) + cipher_ivlen(cipher) > ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH)) { r = SSH_ERR_INTERNAL_ERROR; goto out; } /* check size of shielded key blob */ if (k->shielded_len < cipher_blocksize(cipher) || (k->shielded_len % cipher_blocksize(cipher)) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* Calculate the ephemeral key from the prekey */ if ((r = ssh_digest_memory(SSHKEY_SHIELD_PREKEY_HASH, k->shield_prekey, k->shield_prekey_len, keyiv, SSH_DIGEST_MAX_LENGTH)) != 0) goto out; if ((r = cipher_init(&cctx, cipher, keyiv, cipher_keylen(cipher), keyiv + cipher_keylen(cipher), cipher_ivlen(cipher), 0)) != 0) goto out; #ifdef DEBUG_PK fprintf(stderr, "%s: key+iv\n", __func__); sshbuf_dump_data(keyiv, ssh_digest_bytes(SSHKEY_SHIELD_PREKEY_HASH), stderr); #endif /* Decrypt and parse the shielded private key using the ephemeral key */ if ((prvbuf = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_reserve(prvbuf, k->shielded_len, &cp)) != 0) goto out; /* decrypt */ #ifdef DEBUG_PK fprintf(stderr, "%s: encrypted\n", __func__); sshbuf_dump_data(k->shielded_private, k->shielded_len, stderr); #endif if ((r = cipher_crypt(cctx, 0, cp, k->shielded_private, k->shielded_len, 0, 0)) != 0) goto out; #ifdef DEBUG_PK fprintf(stderr, "%s: serialised\n", __func__); sshbuf_dump(prvbuf, stderr); #endif /* Parse private key */ if ((r = sshkey_private_deserialize(prvbuf, &kswap)) != 0) goto out; /* Check deterministic padding */ i = 0; while (sshbuf_len(prvbuf)) { if ((r = sshbuf_get_u8(prvbuf, &pad)) != 0) goto out; if (pad != (++i & 0xff)) { r = SSH_ERR_INVALID_FORMAT; goto out; } } /* Swap the parsed key back into place */ tmp = *kswap; *kswap = *k; *k = tmp; /* success */ r = 0; out: cipher_free(cctx); explicit_bzero(keyiv, sizeof(keyiv)); explicit_bzero(&tmp, sizeof(tmp)); sshkey_free(kswap); sshbuf_free(prvbuf); return r; } static int cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf) { struct sshbuf *principals = NULL, *crit = NULL; struct sshbuf *exts = NULL, *ca = NULL; u_char *sig = NULL; size_t signed_len = 0, slen = 0, kidlen = 0; int ret = SSH_ERR_INTERNAL_ERROR; /* Copy the entire key blob for verification and later serialisation */ if ((ret = sshbuf_putb(key->cert->certblob, certbuf)) != 0) return ret; /* Parse body of certificate up to signature */ if ((ret = sshbuf_get_u64(b, &key->cert->serial)) != 0 || (ret = sshbuf_get_u32(b, &key->cert->type)) != 0 || (ret = sshbuf_get_cstring(b, &key->cert->key_id, &kidlen)) != 0 || (ret = sshbuf_froms(b, &principals)) != 0 || (ret = sshbuf_get_u64(b, &key->cert->valid_after)) != 0 || (ret = sshbuf_get_u64(b, &key->cert->valid_before)) != 0 || (ret = sshbuf_froms(b, &crit)) != 0 || (ret = sshbuf_froms(b, &exts)) != 0 || (ret = sshbuf_get_string_direct(b, NULL, NULL)) != 0 || (ret = sshbuf_froms(b, &ca)) != 0) { /* XXX debug print error for ret */ ret = SSH_ERR_INVALID_FORMAT; goto out; } /* Signature is left in the buffer so we can calculate this length */ signed_len = sshbuf_len(key->cert->certblob) - sshbuf_len(b); if ((ret = sshbuf_get_string(b, &sig, &slen)) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (key->cert->type != SSH2_CERT_TYPE_USER && key->cert->type != SSH2_CERT_TYPE_HOST) { ret = SSH_ERR_KEY_CERT_UNKNOWN_TYPE; goto out; } /* Parse principals section */ while (sshbuf_len(principals) > 0) { char *principal = NULL; char **oprincipals = NULL; if (key->cert->nprincipals >= SSHKEY_CERT_MAX_PRINCIPALS) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if ((ret = sshbuf_get_cstring(principals, &principal, NULL)) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } oprincipals = key->cert->principals; key->cert->principals = recallocarray(key->cert->principals, key->cert->nprincipals, key->cert->nprincipals + 1, sizeof(*key->cert->principals)); if (key->cert->principals == NULL) { free(principal); key->cert->principals = oprincipals; ret = SSH_ERR_ALLOC_FAIL; goto out; } key->cert->principals[key->cert->nprincipals++] = principal; } /* * Stash a copies of the critical options and extensions sections * for later use. */ if ((ret = sshbuf_putb(key->cert->critical, crit)) != 0 || (exts != NULL && (ret = sshbuf_putb(key->cert->extensions, exts)) != 0)) goto out; /* * Validate critical options and extensions sections format. */ while (sshbuf_len(crit) != 0) { if ((ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0 || (ret = sshbuf_get_string_direct(crit, NULL, NULL)) != 0) { sshbuf_reset(key->cert->critical); ret = SSH_ERR_INVALID_FORMAT; goto out; } } while (exts != NULL && sshbuf_len(exts) != 0) { if ((ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0 || (ret = sshbuf_get_string_direct(exts, NULL, NULL)) != 0) { sshbuf_reset(key->cert->extensions); ret = SSH_ERR_INVALID_FORMAT; goto out; } } /* Parse CA key and check signature */ if (sshkey_from_blob_internal(ca, &key->cert->signature_key, 0) != 0) { ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; goto out; } if (!sshkey_type_is_valid_ca(key->cert->signature_key->type)) { ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; goto out; } if ((ret = sshkey_verify(key->cert->signature_key, sig, slen, sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0)) != 0) goto out; if ((ret = sshkey_get_sigtype(sig, slen, &key->cert->signature_type)) != 0) goto out; /* Success */ ret = 0; out: sshbuf_free(ca); sshbuf_free(crit); sshbuf_free(exts); sshbuf_free(principals); free(sig); return ret; } #ifdef WITH_OPENSSL static int check_rsa_length(const RSA *rsa) { const BIGNUM *rsa_n; RSA_get0_key(rsa, &rsa_n, NULL, NULL); if (BN_num_bits(rsa_n) < SSH_RSA_MINIMUM_MODULUS_SIZE) return SSH_ERR_KEY_LENGTH; return 0; } #endif 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, *xmss_name = NULL; struct sshkey *key = NULL; size_t len; u_char *pk = NULL; struct sshbuf *copy; #if defined(WITH_OPENSSL) BIGNUM *rsa_n = NULL, *rsa_e = NULL; BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL, *dsa_pub_key = NULL; # if defined(OPENSSL_HAS_ECC) EC_POINT *q = NULL; # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ #ifdef DEBUG_PK /* XXX */ sshbuf_dump(b, stderr); #endif if (keyp != NULL) *keyp = NULL; if ((copy = sshbuf_fromb(b)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (sshbuf_get_cstring(b, &ktype, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } type = sshkey_type_from_name(ktype); if (!allow_cert && sshkey_type_is_cert(type)) { ret = SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; goto out; } switch (type) { #ifdef WITH_OPENSSL case KEY_RSA_CERT: /* Skip nonce */ if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } /* FALLTHROUGH */ case KEY_RSA: if ((key = sshkey_new(type)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (sshbuf_get_bignum2(b, &rsa_e) != 0 || sshbuf_get_bignum2(b, &rsa_n) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (!RSA_set0_key(key->rsa, rsa_n, rsa_e, NULL)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_n = rsa_e = NULL; /* transferred */ if ((ret = check_rsa_length(key->rsa)) != 0) 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, &dsa_p) != 0 || sshbuf_get_bignum2(b, &dsa_q) != 0 || sshbuf_get_bignum2(b, &dsa_g) != 0 || sshbuf_get_bignum2(b, &dsa_pub_key) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } if (!DSA_set0_pqg(key->dsa, dsa_p, dsa_q, dsa_g)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_p = dsa_q = dsa_g = NULL; /* transferred */ if (!DSA_set0_key(key->dsa, dsa_pub_key, NULL)) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_pub_key = NULL; /* transferred */ #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; } 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; #ifdef WITH_XMSS case KEY_XMSS_CERT: /* Skip nonce */ if (sshbuf_get_string_direct(b, NULL, NULL) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } /* FALLTHROUGH */ case KEY_XMSS: if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0) goto out; if ((key = sshkey_new(type)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if ((ret = sshkey_xmss_init(key, xmss_name)) != 0) goto out; if ((ret = sshbuf_get_string(b, &pk, &len)) != 0) goto out; if (len == 0 || len != sshkey_xmss_pklen(key)) { ret = SSH_ERR_INVALID_FORMAT; goto out; } key->xmss_pk = pk; pk = NULL; if (type != KEY_XMSS_CERT && (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0) goto out; break; #endif /* WITH_XMSS */ case KEY_UNSPEC: default: ret = SSH_ERR_KEY_TYPE_UNKNOWN; goto out; } /* Parse certificate potion */ if (sshkey_is_cert(key) && (ret = cert_parse(b, key, copy)) != 0) goto out; if (key != NULL && sshbuf_len(b) != 0) { ret = SSH_ERR_INVALID_FORMAT; goto out; } ret = 0; if (keyp != NULL) { *keyp = key; key = NULL; } out: sshbuf_free(copy); sshkey_free(key); free(xmss_name); free(ktype); free(curve); free(pk); #if defined(WITH_OPENSSL) BN_clear_free(rsa_n); BN_clear_free(rsa_e); BN_clear_free(dsa_p); BN_clear_free(dsa_q); BN_clear_free(dsa_g); BN_clear_free(dsa_pub_key); # if defined(OPENSSL_HAS_ECC) EC_POINT_free(q); # endif /* OPENSSL_HAS_ECC */ #endif /* WITH_OPENSSL */ return ret; } int sshkey_from_blob(const u_char *blob, size_t blen, struct sshkey **keyp) { struct sshbuf *b; int r; if ((b = sshbuf_from(blob, blen)) == NULL) return SSH_ERR_ALLOC_FAIL; r = sshkey_from_blob_internal(b, keyp, 1); sshbuf_free(b); return r; } int sshkey_fromb(struct sshbuf *b, struct sshkey **keyp) { return sshkey_from_blob_internal(b, keyp, 1); } int sshkey_froms(struct sshbuf *buf, struct sshkey **keyp) { struct sshbuf *b; int r; if ((r = sshbuf_froms(buf, &b)) != 0) return r; r = sshkey_from_blob_internal(b, keyp, 1); sshbuf_free(b); return r; } int sshkey_get_sigtype(const u_char *sig, size_t siglen, char **sigtypep) { int r; struct sshbuf *b = NULL; char *sigtype = NULL; if (sigtypep != NULL) *sigtypep = NULL; if ((b = sshbuf_from(sig, siglen)) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshbuf_get_cstring(b, &sigtype, NULL)) != 0) goto out; /* success */ if (sigtypep != NULL) { *sigtypep = sigtype; sigtype = NULL; } r = 0; out: free(sigtype); sshbuf_free(b); return r; } /* * * Checks whether a certificate's signature type is allowed. * Returns 0 (success) if the certificate signature type appears in the * "allowed" pattern-list, or the key is not a certificate to begin with. * Otherwise returns a ssherr.h code. */ int sshkey_check_cert_sigtype(const struct sshkey *key, const char *allowed) { if (key == NULL || allowed == NULL) return SSH_ERR_INVALID_ARGUMENT; if (!sshkey_type_is_cert(key->type)) return 0; if (key->cert == NULL || key->cert->signature_type == NULL) return SSH_ERR_INVALID_ARGUMENT; if (match_pattern_list(key->cert->signature_type, allowed, 0) != 1) return SSH_ERR_SIGN_ALG_UNSUPPORTED; return 0; } /* * Returns the expected signature algorithm for a given public key algorithm. */ const char * sshkey_sigalg_by_name(const char *name) { const struct keytype *kt; for (kt = keytypes; kt->type != -1; kt++) { if (strcmp(kt->name, name) != 0) continue; if (kt->sigalg != NULL) return kt->sigalg; if (!kt->cert) return kt->name; return sshkey_ssh_name_from_type_nid( sshkey_type_plain(kt->type), kt->nid); } return NULL; } /* * Verifies that the signature algorithm appearing inside the signature blob * matches that which was requested. */ int sshkey_check_sigtype(const u_char *sig, size_t siglen, const char *requested_alg) { const char *expected_alg; char *sigtype = NULL; int r; if (requested_alg == NULL) return 0; if ((expected_alg = sshkey_sigalg_by_name(requested_alg)) == NULL) return SSH_ERR_INVALID_ARGUMENT; if ((r = sshkey_get_sigtype(sig, siglen, &sigtype)) != 0) return r; r = strcmp(expected_alg, sigtype) == 0; free(sigtype); return r ? 0 : SSH_ERR_SIGN_ALG_UNSUPPORTED; } int sshkey_sign(struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, const char *alg, u_int compat) { int was_shielded = sshkey_is_shielded(key); int r2, r = SSH_ERR_INTERNAL_ERROR; if (sigp != NULL) *sigp = NULL; if (lenp != NULL) *lenp = 0; if (datalen > SSH_KEY_MAX_SIGN_DATA_SIZE) return SSH_ERR_INVALID_ARGUMENT; if ((r = sshkey_unshield_private(key)) != 0) return r; switch (key->type) { #ifdef WITH_OPENSSL case KEY_DSA_CERT: case KEY_DSA: r = ssh_dss_sign(key, sigp, lenp, data, datalen, compat); break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA_CERT: case KEY_ECDSA: r = ssh_ecdsa_sign(key, sigp, lenp, data, datalen, compat); break; # endif /* OPENSSL_HAS_ECC */ case KEY_RSA_CERT: case KEY_RSA: r = ssh_rsa_sign(key, sigp, lenp, data, datalen, alg); break; #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: r = ssh_ed25519_sign(key, sigp, lenp, data, datalen, compat); break; #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: r = ssh_xmss_sign(key, sigp, lenp, data, datalen, compat); break; #endif /* WITH_XMSS */ default: r = SSH_ERR_KEY_TYPE_UNKNOWN; break; } if (was_shielded && (r2 = sshkey_shield_private(key)) != 0) return r2; return r; } /* * ssh_key_verify returns 0 for a correct signature and < 0 on error. * If "alg" specified, then the signature must use that algorithm. */ int sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen, const u_char *data, size_t dlen, const char *alg, u_int compat) { 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, alg); #endif /* WITH_OPENSSL */ case KEY_ED25519: case KEY_ED25519_CERT: return ssh_ed25519_verify(key, sig, siglen, data, dlen, compat); #ifdef WITH_XMSS case KEY_XMSS: case KEY_XMSS_CERT: return ssh_xmss_verify(key, sig, siglen, data, dlen, compat); #endif /* WITH_XMSS */ default: return SSH_ERR_KEY_TYPE_UNKNOWN; } } /* 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; #ifdef WITH_XMSS case KEY_XMSS: newtype = KEY_XMSS_CERT; break; #endif /* WITH_XMSS */ default: return SSH_ERR_INVALID_ARGUMENT; } if ((k->cert = cert_new()) == NULL) return SSH_ERR_ALLOC_FAIL; k->type = newtype; return 0; } /* Convert a certificate to its raw key equivalent */ int sshkey_drop_cert(struct sshkey *k) { if (!sshkey_type_is_cert(k->type)) return SSH_ERR_KEY_TYPE_UNKNOWN; cert_free(k->cert); k->cert = NULL; k->type = sshkey_type_plain(k->type); return 0; } /* Sign a certified key, (re-)generating the signed certblob. */ int sshkey_certify_custom(struct sshkey *k, struct sshkey *ca, const char *alg, sshkey_certify_signer *signer, void *signer_ctx) { struct sshbuf *principals = NULL; u_char *ca_blob = NULL, *sig_blob = NULL, nonce[32]; size_t i, ca_len, sig_len; int ret = SSH_ERR_INTERNAL_ERROR; struct sshbuf *cert = NULL; char *sigtype = NULL; #ifdef WITH_OPENSSL const BIGNUM *rsa_n, *rsa_e, *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key; #endif /* WITH_OPENSSL */ 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 no alg specified as argument but a signature_type was set, * then prefer that. If both were specified, then they must match. */ if (alg == NULL) alg = k->cert->signature_type; else if (k->cert->signature_type != NULL && strcmp(alg, k->cert->signature_type) != 0) return SSH_ERR_INVALID_ARGUMENT; /* * If no signing algorithm or signature_type was specified and we're * using a RSA key, then default to a good signature algorithm. */ if (alg == NULL && ca->type == KEY_RSA) alg = "rsa-sha2-512"; if ((ret = sshkey_to_blob(ca, &ca_blob, &ca_len)) != 0) return SSH_ERR_KEY_CERT_INVALID_SIGN_KEY; cert = k->cert->certblob; /* for readability */ sshbuf_reset(cert); if ((ret = sshbuf_put_cstring(cert, sshkey_ssh_name(k))) != 0) goto out; /* -v01 certs put nonce first */ arc4random_buf(&nonce, sizeof(nonce)); if ((ret = sshbuf_put_string(cert, nonce, sizeof(nonce))) != 0) goto out; /* XXX this substantially duplicates to_blob(); refactor */ switch (k->type) { #ifdef WITH_OPENSSL case KEY_DSA_CERT: DSA_get0_pqg(k->dsa, &dsa_p, &dsa_q, &dsa_g); DSA_get0_key(k->dsa, &dsa_pub_key, NULL); if ((ret = sshbuf_put_bignum2(cert, dsa_p)) != 0 || (ret = sshbuf_put_bignum2(cert, dsa_q)) != 0 || (ret = sshbuf_put_bignum2(cert, dsa_g)) != 0 || (ret = sshbuf_put_bignum2(cert, 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: RSA_get0_key(k->rsa, &rsa_n, &rsa_e, NULL); if ((ret = sshbuf_put_bignum2(cert, rsa_e)) != 0 || (ret = sshbuf_put_bignum2(cert, 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; #ifdef WITH_XMSS case KEY_XMSS_CERT: if (k->xmss_name == NULL) { ret = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((ret = sshbuf_put_cstring(cert, k->xmss_name)) || (ret = sshbuf_put_string(cert, k->xmss_pk, sshkey_xmss_pklen(k))) != 0) goto out; break; #endif /* WITH_XMSS */ default: ret = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((ret = sshbuf_put_u64(cert, k->cert->serial)) != 0 || (ret = sshbuf_put_u32(cert, k->cert->type)) != 0 || (ret = sshbuf_put_cstring(cert, k->cert->key_id)) != 0) goto out; if ((principals = sshbuf_new()) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } for (i = 0; i < k->cert->nprincipals; i++) { if ((ret = sshbuf_put_cstring(principals, k->cert->principals[i])) != 0) goto out; } if ((ret = sshbuf_put_stringb(cert, principals)) != 0 || (ret = sshbuf_put_u64(cert, k->cert->valid_after)) != 0 || (ret = sshbuf_put_u64(cert, k->cert->valid_before)) != 0 || (ret = sshbuf_put_stringb(cert, k->cert->critical)) != 0 || (ret = sshbuf_put_stringb(cert, k->cert->extensions)) != 0 || (ret = sshbuf_put_string(cert, NULL, 0)) != 0 || /* Reserved */ (ret = sshbuf_put_string(cert, ca_blob, ca_len)) != 0) goto out; /* Sign the whole mess */ if ((ret = signer(ca, &sig_blob, &sig_len, sshbuf_ptr(cert), sshbuf_len(cert), alg, 0, signer_ctx)) != 0) goto out; /* Check and update signature_type against what was actually used */ if ((ret = sshkey_get_sigtype(sig_blob, sig_len, &sigtype)) != 0) goto out; if (alg != NULL && strcmp(alg, sigtype) != 0) { ret = SSH_ERR_SIGN_ALG_UNSUPPORTED; goto out; } if (k->cert->signature_type == NULL) { k->cert->signature_type = sigtype; sigtype = NULL; } /* Append signature and we are done */ if ((ret = sshbuf_put_string(cert, sig_blob, sig_len)) != 0) goto out; ret = 0; out: if (ret != 0) sshbuf_reset(cert); free(sig_blob); free(ca_blob); free(sigtype); sshbuf_free(principals); return ret; } static int default_key_sign(struct sshkey *key, u_char **sigp, size_t *lenp, const u_char *data, size_t datalen, const char *alg, u_int compat, void *ctx) { if (ctx != NULL) return SSH_ERR_INVALID_ARGUMENT; return sshkey_sign(key, sigp, lenp, data, datalen, alg, compat); } int sshkey_certify(struct sshkey *k, struct sshkey *ca, const char *alg) { return sshkey_certify_custom(k, ca, alg, default_key_sign, NULL); } int sshkey_cert_check_authority(const struct sshkey *k, int want_host, int require_principal, const char *name, const char **reason) { u_int i, principal_matches; time_t now = time(NULL); if (reason != NULL) *reason = NULL; if (want_host) { if (k->cert->type != SSH2_CERT_TYPE_HOST) { *reason = "Certificate invalid: not a host certificate"; return SSH_ERR_KEY_CERT_INVALID; } } else { if (k->cert->type != SSH2_CERT_TYPE_USER) { *reason = "Certificate invalid: not a user certificate"; return SSH_ERR_KEY_CERT_INVALID; } } if (now < 0) { /* yikes - system clock before epoch! */ *reason = "Certificate invalid: not yet valid"; return SSH_ERR_KEY_CERT_INVALID; } if ((u_int64_t)now < k->cert->valid_after) { *reason = "Certificate invalid: not yet valid"; return SSH_ERR_KEY_CERT_INVALID; } if ((u_int64_t)now >= k->cert->valid_before) { *reason = "Certificate invalid: expired"; return SSH_ERR_KEY_CERT_INVALID; } if (k->cert->nprincipals == 0) { if (require_principal) { *reason = "Certificate lacks principal list"; return SSH_ERR_KEY_CERT_INVALID; } } else if (name != NULL) { principal_matches = 0; for (i = 0; i < k->cert->nprincipals; i++) { #ifdef WINDOWS char cert_principal_name_copy[UNLEN + DNLEN + 1 + 1] = { 0, }; strcpy_s(cert_principal_name_copy, _countof(cert_principal_name_copy), k->cert->principals[i]); /* * For domain user we need special handling. * We support both "domain\user" and "domain/user" formats. * compare user, domain separately. */ if (strstr(name, "/") || strstr(name, "\\")) { char *tmp = NULL; if (tmp = strstr(cert_principal_name_copy, "/")) *tmp = '\\'; } /* In windows, usernames are case insensitive */ if (_strcmpi(name, cert_principal_name_copy) == 0) { #else if (strcmp(name, k->cert->principals[i]) == 0) { #endif principal_matches = 1; break; } } if (!principal_matches) { *reason = "Certificate invalid: name is not a listed " "principal"; return SSH_ERR_KEY_CERT_INVALID; } } return 0; } size_t sshkey_format_cert_validity(const struct sshkey_cert *cert, char *s, size_t l) { char from[32], to[32], ret[64]; time_t tt; struct tm *tm; *from = *to = '\0'; if (cert->valid_after == 0 && cert->valid_before == 0xffffffffffffffffULL) return strlcpy(s, "forever", l); if (cert->valid_after != 0) { /* XXX revisit INT_MAX in 2038 :) */ tt = cert->valid_after > INT_MAX ? INT_MAX : cert->valid_after; tm = localtime(&tt); strftime(from, sizeof(from), "%Y-%m-%dT%H:%M:%S", tm); } if (cert->valid_before != 0xffffffffffffffffULL) { /* XXX revisit INT_MAX in 2038 :) */ tt = cert->valid_before > INT_MAX ? INT_MAX : cert->valid_before; tm = localtime(&tt); strftime(to, sizeof(to), "%Y-%m-%dT%H:%M:%S", tm); } if (cert->valid_after == 0) snprintf(ret, sizeof(ret), "before %s", to); else if (cert->valid_before == 0xffffffffffffffffULL) snprintf(ret, sizeof(ret), "after %s", from); else snprintf(ret, sizeof(ret), "from %s to %s", from, to); return strlcpy(s, ret, l); } int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, enum sshkey_serialize_rep opts) { int r = SSH_ERR_INTERNAL_ERROR; int was_shielded = sshkey_is_shielded(key); struct sshbuf *b = NULL; #ifdef WITH_OPENSSL const BIGNUM *rsa_n, *rsa_e, *rsa_d, *rsa_iqmp, *rsa_p, *rsa_q; const BIGNUM *dsa_p, *dsa_q, *dsa_g, *dsa_pub_key, *dsa_priv_key; #endif /* WITH_OPENSSL */ if ((r = sshkey_unshield_private(key)) != 0) return r; if ((b = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((r = sshbuf_put_cstring(b, sshkey_ssh_name(key))) != 0) goto out; switch (key->type) { #ifdef WITH_OPENSSL case KEY_RSA: RSA_get0_key(key->rsa, &rsa_n, &rsa_e, &rsa_d); RSA_get0_factors(key->rsa, &rsa_p, &rsa_q); RSA_get0_crt_params(key->rsa, NULL, NULL, &rsa_iqmp); if ((r = sshbuf_put_bignum2(b, rsa_n)) != 0 || (r = sshbuf_put_bignum2(b, rsa_e)) != 0 || (r = sshbuf_put_bignum2(b, rsa_d)) != 0 || (r = sshbuf_put_bignum2(b, rsa_iqmp)) != 0 || (r = sshbuf_put_bignum2(b, rsa_p)) != 0 || (r = sshbuf_put_bignum2(b, 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; } RSA_get0_key(key->rsa, NULL, NULL, &rsa_d); RSA_get0_factors(key->rsa, &rsa_p, &rsa_q); RSA_get0_crt_params(key->rsa, NULL, NULL, &rsa_iqmp); if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 || (r = sshbuf_put_bignum2(b, rsa_d)) != 0 || (r = sshbuf_put_bignum2(b, rsa_iqmp)) != 0 || (r = sshbuf_put_bignum2(b, rsa_p)) != 0 || (r = sshbuf_put_bignum2(b, rsa_q)) != 0) goto out; break; case KEY_DSA: DSA_get0_pqg(key->dsa, &dsa_p, &dsa_q, &dsa_g); DSA_get0_key(key->dsa, &dsa_pub_key, &dsa_priv_key); if ((r = sshbuf_put_bignum2(b, dsa_p)) != 0 || (r = sshbuf_put_bignum2(b, dsa_q)) != 0 || (r = sshbuf_put_bignum2(b, dsa_g)) != 0 || (r = sshbuf_put_bignum2(b, dsa_pub_key)) != 0 || (r = sshbuf_put_bignum2(b, 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; } DSA_get0_key(key->dsa, NULL, &dsa_priv_key); if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 || (r = sshbuf_put_bignum2(b, 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; #ifdef WITH_XMSS case KEY_XMSS: if (key->xmss_name == NULL) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 || (r = sshbuf_put_string(b, key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || (r = sshbuf_put_string(b, key->xmss_sk, sshkey_xmss_sklen(key))) != 0 || (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0) goto out; break; case KEY_XMSS_CERT: if (key->cert == NULL || sshbuf_len(key->cert->certblob) == 0 || key->xmss_name == NULL) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((r = sshbuf_put_stringb(b, key->cert->certblob)) != 0 || (r = sshbuf_put_cstring(b, key->xmss_name)) != 0 || (r = sshbuf_put_string(b, key->xmss_pk, sshkey_xmss_pklen(key))) != 0 || (r = sshbuf_put_string(b, key->xmss_sk, sshkey_xmss_sklen(key))) != 0 || (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0) goto out; break; #endif /* WITH_XMSS */ default: r = SSH_ERR_INVALID_ARGUMENT; goto out; } /* * success (but we still need to append the output to buf after * possibly re-shielding the private key) */ r = 0; out: if (was_shielded) r = sshkey_shield_private(key); if (r == 0) r = sshbuf_putb(buf, b); sshbuf_free(b); return r; } int sshkey_private_serialize(struct sshkey *key, struct sshbuf *b) { return sshkey_private_serialize_opt(key, b, SSHKEY_SERIALIZE_DEFAULT); } int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **kp) { char *tname = NULL, *curve = NULL, *xmss_name = 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; u_char *xmss_pk = NULL, *xmss_sk = NULL; #ifdef WITH_OPENSSL BIGNUM *exponent = NULL; BIGNUM *rsa_n = NULL, *rsa_e = NULL, *rsa_d = NULL; BIGNUM *rsa_iqmp = NULL, *rsa_p = NULL, *rsa_q = NULL; BIGNUM *dsa_p = NULL, *dsa_q = NULL, *dsa_g = NULL; BIGNUM *dsa_pub_key = NULL, *dsa_priv_key = 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(type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_get_bignum2(buf, &dsa_p)) != 0 || (r = sshbuf_get_bignum2(buf, &dsa_q)) != 0 || (r = sshbuf_get_bignum2(buf, &dsa_g)) != 0 || (r = sshbuf_get_bignum2(buf, &dsa_pub_key)) != 0 || (r = sshbuf_get_bignum2(buf, &dsa_priv_key)) != 0) goto out; if (!DSA_set0_pqg(k->dsa, dsa_p, dsa_q, dsa_g)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_p = dsa_q = dsa_g = NULL; /* transferred */ if (!DSA_set0_key(k->dsa, dsa_pub_key, dsa_priv_key)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_pub_key = dsa_priv_key = NULL; /* transferred */ break; case KEY_DSA_CERT: if ((r = sshkey_froms(buf, &k)) != 0 || (r = sshbuf_get_bignum2(buf, &dsa_priv_key)) != 0) goto out; if (k->type != type) { r = SSH_ERR_INVALID_FORMAT; goto out; } if (!DSA_set0_key(k->dsa, NULL, dsa_priv_key)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } dsa_priv_key = NULL; /* transferred */ break; # ifdef OPENSSL_HAS_ECC case KEY_ECDSA: if ((k = sshkey_new(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) { 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 ((r = sshkey_froms(buf, &k)) != 0 || (r = sshbuf_get_bignum2(buf, &exponent)) != 0) goto out; if (k->type != type || k->ecdsa_nid != sshkey_ecdsa_nid_from_name(tname)) { r = SSH_ERR_INVALID_FORMAT; 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(type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_get_bignum2(buf, &rsa_n)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_e)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_d)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_iqmp)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_p)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_q)) != 0) goto out; if (!RSA_set0_key(k->rsa, rsa_n, rsa_e, rsa_d)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_n = rsa_e = rsa_d = NULL; /* transferred */ if (!RSA_set0_factors(k->rsa, rsa_p, rsa_q)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_p = rsa_q = NULL; /* transferred */ if ((r = check_rsa_length(k->rsa)) != 0) goto out; if ((r = ssh_rsa_complete_crt_parameters(k, rsa_iqmp)) != 0) goto out; break; case KEY_RSA_CERT: if ((r = sshkey_froms(buf, &k)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_d)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_iqmp)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_p)) != 0 || (r = sshbuf_get_bignum2(buf, &rsa_q)) != 0) goto out; if (k->type != type) { r = SSH_ERR_INVALID_FORMAT; goto out; } if (!RSA_set0_key(k->rsa, NULL, NULL, rsa_d)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_d = NULL; /* transferred */ if (!RSA_set0_factors(k->rsa, rsa_p, rsa_q)) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } rsa_p = rsa_q = NULL; /* transferred */ if ((r = check_rsa_length(k->rsa)) != 0) goto out; if ((r = ssh_rsa_complete_crt_parameters(k, rsa_iqmp)) != 0) goto out; break; #endif /* WITH_OPENSSL */ case KEY_ED25519: if ((k = sshkey_new(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 = sshbuf_get_string(buf, &ed25519_pk, &pklen)) != 0 || (r = sshbuf_get_string(buf, &ed25519_sk, &sklen)) != 0) goto out; if (k->type != type) { r = SSH_ERR_INVALID_FORMAT; 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; /* transferred */ break; #ifdef WITH_XMSS case KEY_XMSS: if ((k = sshkey_new(type)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 || (r = sshkey_xmss_init(k, xmss_name)) != 0 || (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 || (r = sshbuf_get_string(buf, &xmss_sk, &sklen)) != 0) goto out; if (pklen != sshkey_xmss_pklen(k) || sklen != sshkey_xmss_sklen(k)) { r = SSH_ERR_INVALID_FORMAT; goto out; } k->xmss_pk = xmss_pk; k->xmss_sk = xmss_sk; xmss_pk = xmss_sk = NULL; /* optional internal state */ if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0) goto out; break; case KEY_XMSS_CERT: if ((r = sshkey_froms(buf, &k)) != 0 || (r = sshbuf_get_cstring(buf, &xmss_name, NULL)) != 0 || (r = sshbuf_get_string(buf, &xmss_pk, &pklen)) != 0 || (r = sshbuf_get_string(buf, &xmss_sk, &sklen)) != 0) goto out; if (k->type != type || strcmp(xmss_name, k->xmss_name) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } if (pklen != sshkey_xmss_pklen(k) || sklen != sshkey_xmss_sklen(k)) { r = SSH_ERR_INVALID_FORMAT; goto out; } k->xmss_pk = xmss_pk; k->xmss_sk = xmss_sk; xmss_pk = xmss_sk = NULL; /* optional internal state */ if ((r = sshkey_xmss_deserialize_state_opt(k, buf)) != 0) goto out; break; #endif /* WITH_XMSS */ default: r = SSH_ERR_KEY_TYPE_UNKNOWN; goto out; } #ifdef WITH_OPENSSL /* enable blinding */ switch (k->type) { case KEY_RSA: case KEY_RSA_CERT: if (RSA_blinding_on(k->rsa, NULL) != 1) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } break; } #endif /* WITH_OPENSSL */ /* success */ r = 0; if (kp != NULL) { *kp = k; k = NULL; } out: free(tname); free(curve); #ifdef WITH_OPENSSL BN_clear_free(exponent); BN_clear_free(dsa_p); BN_clear_free(dsa_q); BN_clear_free(dsa_g); BN_clear_free(dsa_pub_key); BN_clear_free(dsa_priv_key); BN_clear_free(rsa_n); BN_clear_free(rsa_e); BN_clear_free(rsa_d); BN_clear_free(rsa_p); BN_clear_free(rsa_q); BN_clear_free(rsa_iqmp); #endif /* WITH_OPENSSL */ sshkey_free(k); freezero(ed25519_pk, pklen); freezero(ed25519_sk, sklen); free(xmss_name); freezero(xmss_pk, pklen); freezero(xmss_sk, sklen); return r; } #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC) int sshkey_ec_validate_public(const EC_GROUP *group, const EC_POINT *public) { BN_CTX *bnctx; EC_POINT *nq = NULL; BIGNUM *order, *x, *y, *tmp; int ret = SSH_ERR_KEY_INVALID_EC_VALUE; /* * NB. This assumes OpenSSL has already verified that the public * point lies on the curve. This is done by EC_POINT_oct2point() * implicitly calling EC_POINT_is_on_curve(). If this code is ever * reachable with public points not unmarshalled using * EC_POINT_oct2point then the caller will need to explicitly check. */ if ((bnctx = BN_CTX_new()) == NULL) return SSH_ERR_ALLOC_FAIL; BN_CTX_start(bnctx); /* * We shouldn't ever hit this case because bignum_get_ecpoint() * refuses to load GF2m points. */ if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) != NID_X9_62_prime_field) goto out; /* Q != infinity */ if (EC_POINT_is_at_infinity(group, public)) goto out; if ((x = BN_CTX_get(bnctx)) == NULL || (y = BN_CTX_get(bnctx)) == NULL || (order = BN_CTX_get(bnctx)) == NULL || (tmp = BN_CTX_get(bnctx)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } /* log2(x) > log2(order)/2, log2(y) > log2(order)/2 */ if (EC_GROUP_get_order(group, order, bnctx) != 1 || EC_POINT_get_affine_coordinates_GFp(group, public, x, y, bnctx) != 1) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (BN_num_bits(x) <= BN_num_bits(order) / 2 || BN_num_bits(y) <= BN_num_bits(order) / 2) goto out; /* nQ == infinity (n == order of subgroup) */ if ((nq = EC_POINT_new(group)) == NULL) { ret = SSH_ERR_ALLOC_FAIL; goto out; } if (EC_POINT_mul(group, nq, NULL, public, order, bnctx) != 1) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (EC_POINT_is_at_infinity(group, nq) != 1) goto out; /* x < order - 1, y < order - 1 */ if (!BN_sub(tmp, order, BN_value_one())) { ret = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (BN_cmp(x, tmp) >= 0 || BN_cmp(y, tmp) >= 0) goto out; ret = 0; out: BN_CTX_free(bnctx); 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(struct sshkey *prv, struct sshbuf *blob, const char *passphrase, const char *comment, const char *ciphername, int rounds) { u_char *cp, *key = NULL, *pubkeyblob = NULL; u_char salt[SALT_LEN]; char *b64 = NULL; size_t i, pubkeylen, keylen, ivlen, blocksize, authlen; u_int check; int r = SSH_ERR_INTERNAL_ERROR; struct sshcipher_ctx *ciphercontext = NULL; const struct sshcipher *cipher; const char *kdfname = KDFNAME; struct sshbuf *encoded = NULL, *encrypted = NULL, *kdf = NULL; if (rounds <= 0) rounds = DEFAULT_ROUNDS; if (passphrase == NULL || !strlen(passphrase)) { ciphername = "none"; kdfname = "none"; } else if (ciphername == NULL) ciphername = DEFAULT_CIPHERNAME; if ((cipher = cipher_by_name(ciphername)) == NULL) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((kdf = sshbuf_new()) == NULL || (encoded = sshbuf_new()) == NULL || (encrypted = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } blocksize = cipher_blocksize(cipher); keylen = cipher_keylen(cipher); ivlen = cipher_ivlen(cipher); authlen = cipher_authlen(cipher); if ((key = calloc(1, keylen + ivlen)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (strcmp(kdfname, "bcrypt") == 0) { arc4random_buf(salt, SALT_LEN); if (bcrypt_pbkdf(passphrase, strlen(passphrase), salt, SALT_LEN, key, keylen + ivlen, rounds) < 0) { r = SSH_ERR_INVALID_ARGUMENT; goto out; } if ((r = sshbuf_put_string(kdf, salt, SALT_LEN)) != 0 || (r = sshbuf_put_u32(kdf, rounds)) != 0) goto out; } else if (strcmp(kdfname, "none") != 0) { /* Unsupported KDF type */ r = SSH_ERR_KEY_UNKNOWN_CIPHER; goto out; } if ((r = cipher_init(&ciphercontext, cipher, key, keylen, key + keylen, ivlen, 1)) != 0) goto out; if ((r = sshbuf_put(encoded, AUTH_MAGIC, sizeof(AUTH_MAGIC))) != 0 || (r = sshbuf_put_cstring(encoded, ciphername)) != 0 || (r = sshbuf_put_cstring(encoded, kdfname)) != 0 || (r = sshbuf_put_stringb(encoded, kdf)) != 0 || (r = sshbuf_put_u32(encoded, 1)) != 0 || /* number of keys */ (r = sshkey_to_blob(prv, &pubkeyblob, &pubkeylen)) != 0 || (r = sshbuf_put_string(encoded, pubkeyblob, pubkeylen)) != 0) goto out; /* set up the buffer that will be encrypted */ /* Random check bytes */ check = arc4random(); if ((r = sshbuf_put_u32(encrypted, check)) != 0 || (r = sshbuf_put_u32(encrypted, check)) != 0) goto out; /* append private key and comment*/ if ((r = sshkey_private_serialize_opt(prv, encrypted, SSHKEY_SERIALIZE_FULL)) != 0 || (r = sshbuf_put_cstring(encrypted, comment)) != 0) goto out; /* padding */ i = 0; while (sshbuf_len(encrypted) % blocksize) { if ((r = sshbuf_put_u8(encrypted, ++i & 0xff)) != 0) goto out; } /* length in destination buffer */ if ((r = sshbuf_put_u32(encoded, sshbuf_len(encrypted))) != 0) goto out; /* encrypt */ if ((r = sshbuf_reserve(encoded, sshbuf_len(encrypted) + authlen, &cp)) != 0) goto out; if ((r = cipher_crypt(ciphercontext, 0, cp, sshbuf_ptr(encrypted), sshbuf_len(encrypted), 0, authlen)) != 0) goto out; sshbuf_reset(blob); /* assemble uuencoded key */ if ((r = sshbuf_put(blob, MARK_BEGIN, MARK_BEGIN_LEN)) != 0 || (r = sshbuf_dtob64(encoded, blob, 1)) != 0 || (r = sshbuf_put(blob, MARK_END, MARK_END_LEN)) != 0) goto out; /* success */ r = 0; out: sshbuf_free(kdf); sshbuf_free(encoded); sshbuf_free(encrypted); cipher_free(ciphercontext); explicit_bzero(salt, sizeof(salt)); if (key != NULL) { explicit_bzero(key, keylen + ivlen); free(key); } if (pubkeyblob != NULL) { explicit_bzero(pubkeyblob, pubkeylen); free(pubkeyblob); } if (b64 != NULL) { explicit_bzero(b64, strlen(b64)); free(b64); } return r; } static int sshkey_parse_private2(struct sshbuf *blob, int type, const char *passphrase, struct sshkey **keyp, char **commentp) { char *comment = NULL, *ciphername = NULL, *kdfname = NULL; const struct sshcipher *cipher = NULL; const u_char *cp; int r = SSH_ERR_INTERNAL_ERROR; size_t encoded_len; size_t i, keylen = 0, ivlen = 0, authlen = 0, slen = 0; struct sshbuf *encoded = NULL, *decoded = NULL; struct sshbuf *kdf = NULL, *decrypted = NULL; struct sshcipher_ctx *ciphercontext = NULL; struct sshkey *k = NULL; u_char *key = NULL, *salt = NULL, *dp, pad, last; u_int blocksize, rounds, nkeys, encrypted_len, check1, check2; if (keyp != NULL) *keyp = NULL; if (commentp != NULL) *commentp = NULL; if ((encoded = sshbuf_new()) == NULL || (decoded = sshbuf_new()) == NULL || (decrypted = sshbuf_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } /* check preamble */ cp = sshbuf_ptr(blob); encoded_len = sshbuf_len(blob); #ifdef SUPPORT_CRLF if ((encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) || memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) && (encoded_len < (MARK_BEGIN_LEN_CRLF + MARK_END_LEN_CRLF) || memcmp(cp, MARK_BEGIN_CRLF, MARK_BEGIN_LEN_CRLF) != 0)) { #else /* !SUPPORT_CRLF */ if (encoded_len < (MARK_BEGIN_LEN + MARK_END_LEN) || memcmp(cp, MARK_BEGIN, MARK_BEGIN_LEN) != 0) { #endif /* !SUPPORT_CRLF */ 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') { #ifdef SUPPORT_CRLF if ((encoded_len >= MARK_END_LEN && memcmp(cp, MARK_END, MARK_END_LEN) == 0) || (encoded_len >= MARK_END_LEN_CRLF && memcmp(cp, MARK_END_CRLF, MARK_END_LEN_CRLF) == 0)) { #else /* !SUPPORT_CRLF */ if (encoded_len >= MARK_END_LEN && memcmp(cp, MARK_END, MARK_END_LEN) == 0) { #endif /* !SUPPORT_CRLF */ /* \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) < authlen || sshbuf_len(decoded) - authlen < encrypted_len) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* decrypt private portion of key */ if ((r = sshbuf_reserve(decrypted, encrypted_len, &dp)) != 0 || (r = cipher_init(&ciphercontext, cipher, key, keylen, key + keylen, ivlen, 0)) != 0) goto out; if ((r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(decoded), encrypted_len, 0, authlen)) != 0) { /* an integrity error here indicates an incorrect passphrase */ if (r == SSH_ERR_MAC_INVALID) r = SSH_ERR_KEY_WRONG_PASSPHRASE; goto out; } if ((r = sshbuf_consume(decoded, encrypted_len + authlen)) != 0) goto out; /* there should be no trailing data */ if (sshbuf_len(decoded) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } /* check check bytes */ if ((r = sshbuf_get_u32(decrypted, &check1)) != 0 || (r = sshbuf_get_u32(decrypted, &check2)) != 0) goto out; if (check1 != check2) { r = SSH_ERR_KEY_WRONG_PASSPHRASE; goto out; } /* Load the private key and comment */ if ((r = sshkey_private_deserialize(decrypted, &k)) != 0 || (r = sshbuf_get_cstring(decrypted, &comment, NULL)) != 0) goto out; /* Check deterministic padding */ i = 0; while (sshbuf_len(decrypted)) { if ((r = sshbuf_get_u8(decrypted, &pad)) != 0) goto out; if (pad != (++i & 0xff)) { r = SSH_ERR_INVALID_FORMAT; goto out; } } /* XXX decode pubkey and check against private */ /* success */ r = 0; if (keyp != NULL) { *keyp = k; k = NULL; } if (commentp != NULL) { *commentp = comment; comment = NULL; } out: pad = 0; cipher_free(ciphercontext); free(ciphername); free(kdfname); free(comment); if (salt != NULL) { explicit_bzero(salt, slen); free(salt); } if (key != NULL) { explicit_bzero(key, keylen + ivlen); free(key); } sshbuf_free(encoded); sshbuf_free(decoded); sshbuf_free(kdf); sshbuf_free(decrypted); sshkey_free(k); return r; } #ifdef WITH_OPENSSL /* convert SSH v2 key to PEM or PKCS#8 format */ static int sshkey_private_to_blob_pem_pkcs8(struct sshkey *key, struct sshbuf *buf, int format, const char *_passphrase, const char *comment) { int was_shielded = sshkey_is_shielded(key); int success, r; int blen, len = strlen(_passphrase); u_char *passphrase = (len > 0) ? (u_char *)_passphrase : NULL; const EVP_CIPHER *cipher = (len > 0) ? EVP_aes_128_cbc() : NULL; char *bptr; BIO *bio = NULL; struct sshbuf *blob; EVP_PKEY *pkey = NULL; if (len > 0 && len <= 4) return SSH_ERR_PASSPHRASE_TOO_SHORT; if ((blob = sshbuf_new()) == NULL) return SSH_ERR_ALLOC_FAIL; if ((bio = BIO_new(BIO_s_mem())) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if (format == SSHKEY_PRIVATE_PKCS8 && (pkey = EVP_PKEY_new()) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } if ((r = sshkey_unshield_private(key)) != 0) goto out; switch (key->type) { case KEY_DSA: if (format == SSHKEY_PRIVATE_PEM) { success = PEM_write_bio_DSAPrivateKey(bio, key->dsa, cipher, passphrase, len, NULL, NULL); } else { success = EVP_PKEY_set1_DSA(pkey, key->dsa); } break; #ifdef OPENSSL_HAS_ECC case KEY_ECDSA: if (format == SSHKEY_PRIVATE_PEM) { success = PEM_write_bio_ECPrivateKey(bio, key->ecdsa, cipher, passphrase, len, NULL, NULL); } else { success = EVP_PKEY_set1_EC_KEY(pkey, key->ecdsa); } break; #endif case KEY_RSA: if (format == SSHKEY_PRIVATE_PEM) { success = PEM_write_bio_RSAPrivateKey(bio, key->rsa, cipher, passphrase, len, NULL, NULL); } else { success = EVP_PKEY_set1_RSA(pkey, key->rsa); } break; default: success = 0; break; } if (success == 0) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if (format == SSHKEY_PRIVATE_PKCS8) { if ((success = PEM_write_bio_PrivateKey(bio, pkey, cipher, passphrase, len, NULL, NULL)) == 0) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } } if ((blen = BIO_get_mem_data(bio, &bptr)) <= 0) { r = SSH_ERR_INTERNAL_ERROR; goto out; } if ((r = sshbuf_put(blob, bptr, blen)) != 0) goto out; r = 0; out: if (was_shielded) r = sshkey_shield_private(key); if (r == 0) r = sshbuf_putb(buf, blob); EVP_PKEY_free(pkey); sshbuf_free(blob); BIO_free(bio); return r; } #endif /* WITH_OPENSSL */ /* Serialise "key" to buffer "blob" */ int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, const char *passphrase, const char *comment, int format, const char *openssh_format_cipher, int openssh_format_rounds) { switch (key->type) { #ifdef WITH_OPENSSL case KEY_DSA: case KEY_ECDSA: case KEY_RSA: break; /* see below */ #endif /* WITH_OPENSSL */ case KEY_ED25519: #ifdef WITH_XMSS case KEY_XMSS: #endif /* WITH_XMSS */ return sshkey_private_to_blob2(key, blob, passphrase, comment, openssh_format_cipher, openssh_format_rounds); default: return SSH_ERR_KEY_TYPE_UNKNOWN; } #ifdef WITH_OPENSSL switch (format) { case SSHKEY_PRIVATE_OPENSSH: return sshkey_private_to_blob2(key, blob, passphrase, comment, openssh_format_cipher, openssh_format_rounds); case SSHKEY_PRIVATE_PEM: case SSHKEY_PRIVATE_PKCS8: return sshkey_private_to_blob_pem_pkcs8(key, blob, format, passphrase, comment); default: return SSH_ERR_INVALID_ARGUMENT; } #endif /* WITH_OPENSSL */ } #ifdef WITH_OPENSSL static int translate_libcrypto_error(unsigned long pem_err) { int pem_reason = ERR_GET_REASON(pem_err); switch (ERR_GET_LIB(pem_err)) { case ERR_LIB_PEM: switch (pem_reason) { case PEM_R_BAD_PASSWORD_READ: case PEM_R_PROBLEMS_GETTING_PASSWORD: case PEM_R_BAD_DECRYPT: return SSH_ERR_KEY_WRONG_PASSPHRASE; default: return SSH_ERR_INVALID_FORMAT; } case ERR_LIB_EVP: switch (pem_reason) { case EVP_R_BAD_DECRYPT: return SSH_ERR_KEY_WRONG_PASSPHRASE; #ifdef EVP_R_BN_DECODE_ERROR case EVP_R_BN_DECODE_ERROR: #endif case EVP_R_DECODE_ERROR: #ifdef EVP_R_PRIVATE_KEY_DECODE_ERROR case EVP_R_PRIVATE_KEY_DECODE_ERROR: #endif return SSH_ERR_INVALID_FORMAT; default: return SSH_ERR_LIBCRYPTO_ERROR; } case ERR_LIB_ASN1: return SSH_ERR_INVALID_FORMAT; } return SSH_ERR_LIBCRYPTO_ERROR; } static void clear_libcrypto_errors(void) { while (ERR_get_error() != 0) ; } /* * Translate OpenSSL error codes to determine whether * passphrase is required/incorrect. */ static int convert_libcrypto_error(void) { /* * Some password errors are reported at the beginning * of the error queue. */ if (translate_libcrypto_error(ERR_peek_error()) == SSH_ERR_KEY_WRONG_PASSPHRASE) return SSH_ERR_KEY_WRONG_PASSPHRASE; return translate_libcrypto_error(ERR_peek_last_error()); } static int pem_passphrase_cb(char *buf, int size, int rwflag, void *u) { char *p = (char *)u; size_t len; if (p == NULL || (len = strlen(p)) == 0) return -1; if (size < 0 || len > (size_t)size) return -1; memcpy(buf, p, len); return (int)len; } static int sshkey_parse_private_pem_fileblob(struct sshbuf *blob, int type, const char *passphrase, struct sshkey **keyp) { EVP_PKEY *pk = NULL; struct sshkey *prv = NULL; BIO *bio = NULL; int r; if (keyp != NULL) *keyp = NULL; if ((bio = BIO_new(BIO_s_mem())) == NULL || sshbuf_len(blob) > INT_MAX) return SSH_ERR_ALLOC_FAIL; if (BIO_write(bio, sshbuf_ptr(blob), sshbuf_len(blob)) != (int)sshbuf_len(blob)) { r = SSH_ERR_ALLOC_FAIL; goto out; } clear_libcrypto_errors(); if ((pk = PEM_read_bio_PrivateKey(bio, NULL, pem_passphrase_cb, (char *)passphrase)) == NULL) { /* * libcrypto may return various ASN.1 errors when attempting * to parse a key with an incorrect passphrase. * Treat all format errors as "incorrect passphrase" if a * passphrase was supplied. */ if (passphrase != NULL && *passphrase != '\0') r = SSH_ERR_KEY_WRONG_PASSPHRASE; else r = convert_libcrypto_error(); goto out; } if (EVP_PKEY_base_id(pk) == EVP_PKEY_RSA && (type == KEY_UNSPEC || type == KEY_RSA)) { if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } prv->rsa = EVP_PKEY_get1_RSA(pk); prv->type = KEY_RSA; #ifdef DEBUG_PK RSA_print_fp(stderr, prv->rsa, 8); #endif if (RSA_blinding_on(prv->rsa, NULL) != 1) { r = SSH_ERR_LIBCRYPTO_ERROR; goto out; } if ((r = check_rsa_length(prv->rsa)) != 0) goto out; } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_DSA && (type == KEY_UNSPEC || type == KEY_DSA)) { if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } prv->dsa = EVP_PKEY_get1_DSA(pk); prv->type = KEY_DSA; #ifdef DEBUG_PK DSA_print_fp(stderr, prv->dsa, 8); #endif #ifdef OPENSSL_HAS_ECC } else if (EVP_PKEY_base_id(pk) == EVP_PKEY_EC && (type == KEY_UNSPEC || type == KEY_ECDSA)) { if ((prv = sshkey_new(KEY_UNSPEC)) == NULL) { r = SSH_ERR_ALLOC_FAIL; goto out; } prv->ecdsa = EVP_PKEY_get1_EC_KEY(pk); prv->type = KEY_ECDSA; prv->ecdsa_nid = sshkey_ecdsa_key_to_nid(prv->ecdsa); if (prv->ecdsa_nid == -1 || sshkey_curve_nid_to_name(prv->ecdsa_nid) == NULL || sshkey_ec_validate_public(EC_KEY_get0_group(prv->ecdsa), EC_KEY_get0_public_key(prv->ecdsa)) != 0 || sshkey_ec_validate_private(prv->ecdsa) != 0) { r = SSH_ERR_INVALID_FORMAT; goto out; } # ifdef DEBUG_PK if (prv != NULL && prv->ecdsa != NULL) sshkey_dump_ec_key(prv->ecdsa); # endif #endif /* OPENSSL_HAS_ECC */ } else { r = SSH_ERR_INVALID_FORMAT; goto out; } r = 0; if (keyp != NULL) { *keyp = prv; prv = NULL; } out: BIO_free(bio); EVP_PKEY_free(pk); sshkey_free(prv); return r; } #endif /* WITH_OPENSSL */ int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, const char *passphrase, struct sshkey **keyp, char **commentp) { int r = SSH_ERR_INTERNAL_ERROR; if (keyp != NULL) *keyp = NULL; if (commentp != NULL) *commentp = NULL; switch (type) { #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: #ifdef WITH_XMSS case KEY_XMSS: #endif /* WITH_XMSS */ return sshkey_parse_private2(blob, type, passphrase, keyp, commentp); case KEY_UNSPEC: r = sshkey_parse_private2(blob, type, passphrase, keyp, commentp); /* Do not fallback to PEM parser if only passphrase is wrong. */ if (r == 0 || r == SSH_ERR_KEY_WRONG_PASSPHRASE) return r; #ifdef WITH_OPENSSL return sshkey_parse_private_pem_fileblob(blob, type, passphrase, keyp); #else return SSH_ERR_INVALID_FORMAT; #endif /* WITH_OPENSSL */ default: return SSH_ERR_KEY_TYPE_UNKNOWN; } } int sshkey_parse_private_fileblob(struct sshbuf *buffer, const char *passphrase, struct sshkey **keyp, char **commentp) { if (keyp != NULL) *keyp = NULL; if (commentp != NULL) *commentp = NULL; return sshkey_parse_private_fileblob_type(buffer, KEY_UNSPEC, passphrase, keyp, commentp); } #ifdef WITH_XMSS /* * serialize the key with the current state and forward the state * maxsign times. */ int sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b, u_int32_t maxsign, sshkey_printfn *pr) { int r, rupdate; if (maxsign == 0 || sshkey_type_plain(k->type) != KEY_XMSS) return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT); if ((r = sshkey_xmss_get_state(k, pr)) != 0 || (r = sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_STATE)) != 0 || (r = sshkey_xmss_forward_state(k, maxsign)) != 0) goto out; r = 0; out: if ((rupdate = sshkey_xmss_update_state(k, pr)) != 0) { if (r == 0) r = rupdate; } return r; } u_int32_t sshkey_signatures_left(const struct sshkey *k) { if (sshkey_type_plain(k->type) == KEY_XMSS) return sshkey_xmss_signatures_left(k); return 0; } int sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign) { if (sshkey_type_plain(k->type) != KEY_XMSS) return SSH_ERR_INVALID_ARGUMENT; return sshkey_xmss_enable_maxsign(k, maxsign); } int sshkey_set_filename(struct sshkey *k, const char *filename) { if (k == NULL) return SSH_ERR_INVALID_ARGUMENT; if (sshkey_type_plain(k->type) != KEY_XMSS) return 0; if (filename == NULL) return SSH_ERR_INVALID_ARGUMENT; if ((k->xmss_filename = strdup(filename)) == NULL) return SSH_ERR_ALLOC_FAIL; return 0; } #else int sshkey_private_serialize_maxsign(struct sshkey *k, struct sshbuf *b, u_int32_t maxsign, sshkey_printfn *pr) { return sshkey_private_serialize_opt(k, b, SSHKEY_SERIALIZE_DEFAULT); } u_int32_t sshkey_signatures_left(const struct sshkey *k) { return 0; } int sshkey_enable_maxsign(struct sshkey *k, u_int32_t maxsign) { return SSH_ERR_INVALID_ARGUMENT; } int sshkey_set_filename(struct sshkey *k, const char *filename) { if (k == NULL) return SSH_ERR_INVALID_ARGUMENT; return 0; } #endif /* WITH_XMSS */