/* * DPP crypto functionality * Copyright (c) 2017, Qualcomm Atheros, Inc. * Copyright (c) 2018-2020, The Linux Foundation * * This software may be distributed under the terms of the BSD license. * See README for more details. */ #include "utils/includes.h" #include #include #include #include #include #include "utils/common.h" #include "utils/base64.h" #include "utils/json.h" #include "common/ieee802_11_defs.h" #include "crypto/crypto.h" #include "crypto/random.h" #include "crypto/sha384.h" #include "crypto/sha512.h" #include "dpp.h" #include "dpp_i.h" #if OPENSSL_VERSION_NUMBER < 0x10100000L || \ (defined(LIBRESSL_VERSION_NUMBER) && \ LIBRESSL_VERSION_NUMBER < 0x20700000L) /* Compatibility wrappers for older versions. */ static int ECDSA_SIG_set0(ECDSA_SIG *sig, BIGNUM *r, BIGNUM *s) { sig->r = r; sig->s = s; return 1; } static void ECDSA_SIG_get0(const ECDSA_SIG *sig, const BIGNUM **pr, const BIGNUM **ps) { if (pr) *pr = sig->r; if (ps) *ps = sig->s; } static EC_KEY * EVP_PKEY_get0_EC_KEY(EVP_PKEY *pkey) { if (pkey->type != EVP_PKEY_EC) return NULL; return pkey->pkey.ec; } #endif static const struct dpp_curve_params dpp_curves[] = { /* The mandatory to support and the default NIST P-256 curve needs to * be the first entry on this list. */ { "prime256v1", 32, 32, 16, 32, "P-256", 19, "ES256" }, { "secp384r1", 48, 48, 24, 48, "P-384", 20, "ES384" }, { "secp521r1", 64, 64, 32, 66, "P-521", 21, "ES512" }, { "brainpoolP256r1", 32, 32, 16, 32, "BP-256", 28, "BS256" }, { "brainpoolP384r1", 48, 48, 24, 48, "BP-384", 29, "BS384" }, { "brainpoolP512r1", 64, 64, 32, 64, "BP-512", 30, "BS512" }, { NULL, 0, 0, 0, 0, NULL, 0, NULL } }; const struct dpp_curve_params * dpp_get_curve_name(const char *name) { int i; if (!name) return &dpp_curves[0]; for (i = 0; dpp_curves[i].name; i++) { if (os_strcmp(name, dpp_curves[i].name) == 0 || (dpp_curves[i].jwk_crv && os_strcmp(name, dpp_curves[i].jwk_crv) == 0)) return &dpp_curves[i]; } return NULL; } const struct dpp_curve_params * dpp_get_curve_jwk_crv(const char *name) { int i; for (i = 0; dpp_curves[i].name; i++) { if (dpp_curves[i].jwk_crv && os_strcmp(name, dpp_curves[i].jwk_crv) == 0) return &dpp_curves[i]; } return NULL; } static const struct dpp_curve_params * dpp_get_curve_oid(const ASN1_OBJECT *poid) { ASN1_OBJECT *oid; int i; for (i = 0; dpp_curves[i].name; i++) { oid = OBJ_txt2obj(dpp_curves[i].name, 0); if (oid && OBJ_cmp(poid, oid) == 0) return &dpp_curves[i]; } return NULL; } const struct dpp_curve_params * dpp_get_curve_nid(int nid) { int i, tmp; if (!nid) return NULL; for (i = 0; dpp_curves[i].name; i++) { tmp = OBJ_txt2nid(dpp_curves[i].name); if (tmp == nid) return &dpp_curves[i]; } return NULL; } const struct dpp_curve_params * dpp_get_curve_ike_group(u16 group) { int i; for (i = 0; dpp_curves[i].name; i++) { if (dpp_curves[i].ike_group == group) return &dpp_curves[i]; } return NULL; } void dpp_debug_print_point(const char *title, const EC_GROUP *group, const EC_POINT *point) { BIGNUM *x, *y; BN_CTX *ctx; char *x_str = NULL, *y_str = NULL; if (!wpa_debug_show_keys) return; ctx = BN_CTX_new(); x = BN_new(); y = BN_new(); if (!ctx || !x || !y || EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx) != 1) goto fail; x_str = BN_bn2hex(x); y_str = BN_bn2hex(y); if (!x_str || !y_str) goto fail; wpa_printf(MSG_DEBUG, "%s (%s,%s)", title, x_str, y_str); fail: OPENSSL_free(x_str); OPENSSL_free(y_str); BN_free(x); BN_free(y); BN_CTX_free(ctx); } void dpp_debug_print_key(const char *title, struct crypto_ec_key *key) { EC_KEY *eckey; BIO *out; size_t rlen; char *txt; int res; struct wpabuf *der = NULL; const EC_GROUP *group; const EC_POINT *point; out = BIO_new(BIO_s_mem()); if (!out) return; EVP_PKEY_print_private(out, (EVP_PKEY *) key, 0, NULL); rlen = BIO_ctrl_pending(out); txt = os_malloc(rlen + 1); if (txt) { res = BIO_read(out, txt, rlen); if (res > 0) { txt[res] = '\0'; wpa_printf(MSG_DEBUG, "%s: %s", title, txt); } os_free(txt); } BIO_free(out); eckey = EVP_PKEY_get1_EC_KEY((EVP_PKEY *) key); if (!eckey) return; group = EC_KEY_get0_group(eckey); point = EC_KEY_get0_public_key(eckey); if (group && point) dpp_debug_print_point(title, group, point); der = crypto_ec_key_get_ecprivate_key(key, true); if (der) { wpa_hexdump_buf_key(MSG_DEBUG, "DPP: ECPrivateKey", der); } else { der = crypto_ec_key_get_subject_public_key(key); if (der) wpa_hexdump_buf_key(MSG_DEBUG, "DPP: EC_PUBKEY", der); } EC_KEY_free(eckey); wpabuf_clear_free(der); } static int dpp_hash_vector(const struct dpp_curve_params *curve, size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac) { if (curve->hash_len == 32) return sha256_vector(num_elem, addr, len, mac); if (curve->hash_len == 48) return sha384_vector(num_elem, addr, len, mac); if (curve->hash_len == 64) return sha512_vector(num_elem, addr, len, mac); return -1; } int dpp_hkdf_expand(size_t hash_len, const u8 *secret, size_t secret_len, const char *label, u8 *out, size_t outlen) { if (hash_len == 32) return hmac_sha256_kdf(secret, secret_len, NULL, (const u8 *) label, os_strlen(label), out, outlen); if (hash_len == 48) return hmac_sha384_kdf(secret, secret_len, NULL, (const u8 *) label, os_strlen(label), out, outlen); if (hash_len == 64) return hmac_sha512_kdf(secret, secret_len, NULL, (const u8 *) label, os_strlen(label), out, outlen); return -1; } int dpp_hmac_vector(size_t hash_len, const u8 *key, size_t key_len, size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac) { if (hash_len == 32) return hmac_sha256_vector(key, key_len, num_elem, addr, len, mac); if (hash_len == 48) return hmac_sha384_vector(key, key_len, num_elem, addr, len, mac); if (hash_len == 64) return hmac_sha512_vector(key, key_len, num_elem, addr, len, mac); return -1; } static int dpp_hmac(size_t hash_len, const u8 *key, size_t key_len, const u8 *data, size_t data_len, u8 *mac) { if (hash_len == 32) return hmac_sha256(key, key_len, data, data_len, mac); if (hash_len == 48) return hmac_sha384(key, key_len, data, data_len, mac); if (hash_len == 64) return hmac_sha512(key, key_len, data, data_len, mac); return -1; } #ifdef CONFIG_DPP2 static int dpp_pbkdf2_f(size_t hash_len, const u8 *password, size_t password_len, const u8 *salt, size_t salt_len, unsigned int iterations, unsigned int count, u8 *digest) { unsigned char tmp[DPP_MAX_HASH_LEN], tmp2[DPP_MAX_HASH_LEN]; unsigned int i; size_t j; u8 count_buf[4]; const u8 *addr[2]; size_t len[2]; addr[0] = salt; len[0] = salt_len; addr[1] = count_buf; len[1] = 4; /* F(P, S, c, i) = U1 xor U2 xor ... Uc * U1 = PRF(P, S || i) * U2 = PRF(P, U1) * Uc = PRF(P, Uc-1) */ WPA_PUT_BE32(count_buf, count); if (dpp_hmac_vector(hash_len, password, password_len, 2, addr, len, tmp)) return -1; os_memcpy(digest, tmp, hash_len); for (i = 1; i < iterations; i++) { if (dpp_hmac(hash_len, password, password_len, tmp, hash_len, tmp2)) return -1; os_memcpy(tmp, tmp2, hash_len); for (j = 0; j < hash_len; j++) digest[j] ^= tmp2[j]; } return 0; } int dpp_pbkdf2(size_t hash_len, const u8 *password, size_t password_len, const u8 *salt, size_t salt_len, unsigned int iterations, u8 *buf, size_t buflen) { unsigned int count = 0; unsigned char *pos = buf; size_t left = buflen, plen; unsigned char digest[DPP_MAX_HASH_LEN]; while (left > 0) { count++; if (dpp_pbkdf2_f(hash_len, password, password_len, salt, salt_len, iterations, count, digest)) return -1; plen = left > hash_len ? hash_len : left; os_memcpy(pos, digest, plen); pos += plen; left -= plen; } return 0; } #endif /* CONFIG_DPP2 */ int dpp_bn2bin_pad(const BIGNUM *bn, u8 *pos, size_t len) { int num_bytes, offset; num_bytes = BN_num_bytes(bn); if ((size_t) num_bytes > len) return -1; offset = len - num_bytes; os_memset(pos, 0, offset); BN_bn2bin(bn, pos + offset); return 0; } struct wpabuf * dpp_get_pubkey_point(struct crypto_ec_key *key, int prefix) { int len, res; EC_KEY *eckey; struct wpabuf *buf; unsigned char *pos; eckey = EVP_PKEY_get1_EC_KEY((EVP_PKEY *) key); if (!eckey) return NULL; EC_KEY_set_conv_form(eckey, POINT_CONVERSION_UNCOMPRESSED); len = i2o_ECPublicKey(eckey, NULL); if (len <= 0) { wpa_printf(MSG_ERROR, "DDP: Failed to determine public key encoding length"); EC_KEY_free(eckey); return NULL; } buf = wpabuf_alloc(len); if (!buf) { EC_KEY_free(eckey); return NULL; } pos = wpabuf_put(buf, len); res = i2o_ECPublicKey(eckey, &pos); EC_KEY_free(eckey); if (res != len) { wpa_printf(MSG_ERROR, "DDP: Failed to encode public key (res=%d/%d)", res, len); wpabuf_free(buf); return NULL; } if (!prefix) { /* Remove 0x04 prefix to match DPP definition */ pos = wpabuf_mhead(buf); os_memmove(pos, pos + 1, len - 1); buf->used--; } return buf; } struct crypto_ec_key * dpp_set_pubkey_point_group(const EC_GROUP *group, const u8 *buf_x, const u8 *buf_y, size_t len) { EC_KEY *eckey = NULL; BN_CTX *ctx; EC_POINT *point = NULL; BIGNUM *x = NULL, *y = NULL; EVP_PKEY *pkey = NULL; ctx = BN_CTX_new(); if (!ctx) { wpa_printf(MSG_ERROR, "DPP: Out of memory"); return NULL; } point = EC_POINT_new(group); x = BN_bin2bn(buf_x, len, NULL); y = BN_bin2bn(buf_y, len, NULL); if (!point || !x || !y) { wpa_printf(MSG_ERROR, "DPP: Out of memory"); goto fail; } if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) { wpa_printf(MSG_ERROR, "DPP: OpenSSL: EC_POINT_set_affine_coordinates_GFp failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (!EC_POINT_is_on_curve(group, point, ctx) || EC_POINT_is_at_infinity(group, point)) { wpa_printf(MSG_ERROR, "DPP: Invalid point"); goto fail; } dpp_debug_print_point("DPP: dpp_set_pubkey_point_group", group, point); eckey = EC_KEY_new(); if (!eckey || EC_KEY_set_group(eckey, group) != 1 || EC_KEY_set_public_key(eckey, point) != 1) { wpa_printf(MSG_ERROR, "DPP: Failed to set EC_KEY: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } EC_KEY_set_asn1_flag(eckey, OPENSSL_EC_NAMED_CURVE); pkey = EVP_PKEY_new(); if (!pkey || EVP_PKEY_set1_EC_KEY(pkey, eckey) != 1) { wpa_printf(MSG_ERROR, "DPP: Could not create EVP_PKEY"); goto fail; } out: BN_free(x); BN_free(y); EC_KEY_free(eckey); EC_POINT_free(point); BN_CTX_free(ctx); return (struct crypto_ec_key *) pkey; fail: EVP_PKEY_free(pkey); pkey = NULL; goto out; } struct crypto_ec_key * dpp_set_pubkey_point(struct crypto_ec_key *group_key, const u8 *buf, size_t len) { const EC_KEY *eckey; const EC_GROUP *group; struct crypto_ec_key *pkey = NULL; if (len & 1) return NULL; eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) group_key); if (!eckey) { wpa_printf(MSG_ERROR, "DPP: Could not get EC_KEY from group_key"); return NULL; } group = EC_KEY_get0_group(eckey); if (group) pkey = dpp_set_pubkey_point_group(group, buf, buf + len / 2, len / 2); else wpa_printf(MSG_ERROR, "DPP: Could not get EC group"); return pkey; } struct crypto_ec_key * dpp_gen_keypair(const struct dpp_curve_params *curve) { struct crypto_ec_key *key; wpa_printf(MSG_DEBUG, "DPP: Generating a keypair"); key = crypto_ec_key_gen(curve->ike_group); if (key && wpa_debug_show_keys) dpp_debug_print_key("Own generated key", key); return key; } struct crypto_ec_key * dpp_set_keypair(const struct dpp_curve_params **curve, const u8 *privkey, size_t privkey_len) { EVP_PKEY *pkey; EC_KEY *eckey; const EC_GROUP *group; int nid; pkey = EVP_PKEY_new(); if (!pkey) return NULL; eckey = d2i_ECPrivateKey(NULL, &privkey, privkey_len); if (!eckey) { wpa_printf(MSG_INFO, "DPP: OpenSSL: d2i_ECPrivateKey() failed: %s", ERR_error_string(ERR_get_error(), NULL)); EVP_PKEY_free(pkey); return NULL; } group = EC_KEY_get0_group(eckey); if (!group) { EC_KEY_free(eckey); EVP_PKEY_free(pkey); return NULL; } nid = EC_GROUP_get_curve_name(group); *curve = dpp_get_curve_nid(nid); if (!*curve) { wpa_printf(MSG_INFO, "DPP: Unsupported curve (nid=%d) in pre-assigned key", nid); EC_KEY_free(eckey); EVP_PKEY_free(pkey); return NULL; } if (EVP_PKEY_assign_EC_KEY(pkey, eckey) != 1) { EC_KEY_free(eckey); EVP_PKEY_free(pkey); return NULL; } return (struct crypto_ec_key *) pkey; } typedef struct { /* AlgorithmIdentifier ecPublicKey with optional parameters present * as an OID identifying the curve */ X509_ALGOR *alg; /* Compressed format public key per ANSI X9.63 */ ASN1_BIT_STRING *pub_key; } DPP_BOOTSTRAPPING_KEY; ASN1_SEQUENCE(DPP_BOOTSTRAPPING_KEY) = { ASN1_SIMPLE(DPP_BOOTSTRAPPING_KEY, alg, X509_ALGOR), ASN1_SIMPLE(DPP_BOOTSTRAPPING_KEY, pub_key, ASN1_BIT_STRING) } ASN1_SEQUENCE_END(DPP_BOOTSTRAPPING_KEY); IMPLEMENT_ASN1_FUNCTIONS(DPP_BOOTSTRAPPING_KEY); static struct wpabuf * dpp_bootstrap_key_der(struct crypto_ec_key *key) { unsigned char *der = NULL; int der_len; const EC_KEY *eckey; struct wpabuf *ret = NULL; size_t len; const EC_GROUP *group; const EC_POINT *point; BN_CTX *ctx; DPP_BOOTSTRAPPING_KEY *bootstrap = NULL; int nid; ctx = BN_CTX_new(); eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) key); if (!ctx || !eckey) goto fail; group = EC_KEY_get0_group(eckey); point = EC_KEY_get0_public_key(eckey); if (!group || !point) goto fail; dpp_debug_print_point("DPP: bootstrap public key", group, point); nid = EC_GROUP_get_curve_name(group); bootstrap = DPP_BOOTSTRAPPING_KEY_new(); if (!bootstrap || X509_ALGOR_set0(bootstrap->alg, OBJ_nid2obj(EVP_PKEY_EC), V_ASN1_OBJECT, (void *) OBJ_nid2obj(nid)) != 1) goto fail; len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, NULL, 0, ctx); if (len == 0) goto fail; der = OPENSSL_malloc(len); if (!der) goto fail; len = EC_POINT_point2oct(group, point, POINT_CONVERSION_COMPRESSED, der, len, ctx); OPENSSL_free(bootstrap->pub_key->data); bootstrap->pub_key->data = der; der = NULL; bootstrap->pub_key->length = len; /* No unused bits */ bootstrap->pub_key->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT | 0x07); bootstrap->pub_key->flags |= ASN1_STRING_FLAG_BITS_LEFT; der_len = i2d_DPP_BOOTSTRAPPING_KEY(bootstrap, &der); if (der_len <= 0) { wpa_printf(MSG_ERROR, "DDP: Failed to build DER encoded public key"); goto fail; } ret = wpabuf_alloc_copy(der, der_len); fail: DPP_BOOTSTRAPPING_KEY_free(bootstrap); OPENSSL_free(der); BN_CTX_free(ctx); return ret; } int dpp_bootstrap_key_hash(struct dpp_bootstrap_info *bi) { struct wpabuf *der; int res; der = dpp_bootstrap_key_der(bi->pubkey); if (!der) return -1; wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)", der); res = dpp_bi_pubkey_hash(bi, wpabuf_head(der), wpabuf_len(der)); if (res < 0) wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key"); wpabuf_free(der); return res; } int dpp_keygen(struct dpp_bootstrap_info *bi, const char *curve, const u8 *privkey, size_t privkey_len) { char *base64 = NULL; char *pos, *end; size_t len; struct wpabuf *der = NULL; bi->curve = dpp_get_curve_name(curve); if (!bi->curve) { wpa_printf(MSG_INFO, "DPP: Unsupported curve: %s", curve); return -1; } if (privkey) bi->pubkey = dpp_set_keypair(&bi->curve, privkey, privkey_len); else bi->pubkey = dpp_gen_keypair(bi->curve); if (!bi->pubkey) goto fail; bi->own = 1; der = dpp_bootstrap_key_der(bi->pubkey); if (!der) goto fail; wpa_hexdump_buf(MSG_DEBUG, "DPP: Compressed public key (DER)", der); if (dpp_bi_pubkey_hash(bi, wpabuf_head(der), wpabuf_len(der)) < 0) { wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key"); goto fail; } base64 = base64_encode(wpabuf_head(der), wpabuf_len(der), &len); wpabuf_free(der); der = NULL; if (!base64) goto fail; pos = base64; end = pos + len; for (;;) { pos = os_strchr(pos, '\n'); if (!pos) break; os_memmove(pos, pos + 1, end - pos); } os_free(bi->pk); bi->pk = base64; return 0; fail: os_free(base64); wpabuf_free(der); return -1; } int dpp_derive_k1(const u8 *Mx, size_t Mx_len, u8 *k1, unsigned int hash_len) { u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN]; const char *info = "first intermediate key"; int res; /* k1 = HKDF(<>, "first intermediate key", M.x) */ /* HKDF-Extract(<>, M.x) */ os_memset(salt, 0, hash_len); if (dpp_hmac(hash_len, salt, hash_len, Mx, Mx_len, prk) < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=M.x)", prk, hash_len); /* HKDF-Expand(PRK, info, L) */ res = dpp_hkdf_expand(hash_len, prk, hash_len, info, k1, hash_len); os_memset(prk, 0, hash_len); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: k1 = HKDF-Expand(PRK, info, L)", k1, hash_len); return 0; } int dpp_derive_k2(const u8 *Nx, size_t Nx_len, u8 *k2, unsigned int hash_len) { u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN]; const char *info = "second intermediate key"; int res; /* k2 = HKDF(<>, "second intermediate key", N.x) */ /* HKDF-Extract(<>, N.x) */ os_memset(salt, 0, hash_len); res = dpp_hmac(hash_len, salt, hash_len, Nx, Nx_len, prk); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=N.x)", prk, hash_len); /* HKDF-Expand(PRK, info, L) */ res = dpp_hkdf_expand(hash_len, prk, hash_len, info, k2, hash_len); os_memset(prk, 0, hash_len); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: k2 = HKDF-Expand(PRK, info, L)", k2, hash_len); return 0; } int dpp_derive_bk_ke(struct dpp_authentication *auth) { unsigned int hash_len = auth->curve->hash_len; size_t nonce_len = auth->curve->nonce_len; u8 nonces[2 * DPP_MAX_NONCE_LEN]; const char *info_ke = "DPP Key"; int res; const u8 *addr[3]; size_t len[3]; size_t num_elem = 0; if (!auth->Mx_len || !auth->Nx_len) { wpa_printf(MSG_DEBUG, "DPP: Mx/Nx not available - cannot derive ke"); return -1; } /* bk = HKDF-Extract(I-nonce | R-nonce, M.x | N.x [| L.x]) */ os_memcpy(nonces, auth->i_nonce, nonce_len); os_memcpy(&nonces[nonce_len], auth->r_nonce, nonce_len); addr[num_elem] = auth->Mx; len[num_elem] = auth->Mx_len; num_elem++; addr[num_elem] = auth->Nx; len[num_elem] = auth->Nx_len; num_elem++; if (auth->peer_bi && auth->own_bi) { if (!auth->Lx_len) { wpa_printf(MSG_DEBUG, "DPP: Lx not available - cannot derive ke"); return -1; } addr[num_elem] = auth->Lx; len[num_elem] = auth->secret_len; num_elem++; } res = dpp_hmac_vector(hash_len, nonces, 2 * nonce_len, num_elem, addr, len, auth->bk); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: bk = HKDF-Extract(I-nonce | R-nonce, M.x | N.x [| L.x])", auth->bk, hash_len); /* ke = HKDF-Expand(bk, "DPP Key", length) */ res = dpp_hkdf_expand(hash_len, auth->bk, hash_len, info_ke, auth->ke, hash_len); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: ke = HKDF-Expand(bk, \"DPP Key\", length)", auth->ke, hash_len); return 0; } int dpp_ecdh(struct crypto_ec_key *own, struct crypto_ec_key *peer, u8 *secret, size_t *secret_len) { EVP_PKEY_CTX *ctx; int ret = -1; ERR_clear_error(); *secret_len = 0; ctx = EVP_PKEY_CTX_new((EVP_PKEY *) own, NULL); if (!ctx) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_CTX_new failed: %s", ERR_error_string(ERR_get_error(), NULL)); return -1; } if (EVP_PKEY_derive_init(ctx) != 1) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_derive_init failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (EVP_PKEY_derive_set_peer(ctx, (EVP_PKEY *) peer) != 1) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_derive_set_peet failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (EVP_PKEY_derive(ctx, NULL, secret_len) != 1) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_derive(NULL) failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (*secret_len > DPP_MAX_SHARED_SECRET_LEN) { u8 buf[200]; int level = *secret_len > 200 ? MSG_ERROR : MSG_DEBUG; /* It looks like OpenSSL can return unexpectedly large buffer * need for shared secret from EVP_PKEY_derive(NULL) in some * cases. For example, group 19 has shown cases where secret_len * is set to 72 even though the actual length ends up being * updated to 32 when EVP_PKEY_derive() is called with a buffer * for the value. Work around this by trying to fetch the value * and continue if it is within supported range even when the * initial buffer need is claimed to be larger. */ wpa_printf(level, "DPP: Unexpected secret_len=%d from EVP_PKEY_derive()", (int) *secret_len); if (*secret_len > 200) goto fail; if (EVP_PKEY_derive(ctx, buf, secret_len) != 1) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_derive failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (*secret_len > DPP_MAX_SHARED_SECRET_LEN) { wpa_printf(MSG_ERROR, "DPP: Unexpected secret_len=%d from EVP_PKEY_derive()", (int) *secret_len); goto fail; } wpa_hexdump_key(MSG_DEBUG, "DPP: Unexpected secret_len change", buf, *secret_len); os_memcpy(secret, buf, *secret_len); forced_memzero(buf, sizeof(buf)); goto done; } if (EVP_PKEY_derive(ctx, secret, secret_len) != 1) { wpa_printf(MSG_ERROR, "DPP: EVP_PKEY_derive failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } done: ret = 0; fail: EVP_PKEY_CTX_free(ctx); return ret; } int dpp_bi_pubkey_hash(struct dpp_bootstrap_info *bi, const u8 *data, size_t data_len) { const u8 *addr[2]; size_t len[2]; addr[0] = data; len[0] = data_len; if (sha256_vector(1, addr, len, bi->pubkey_hash) < 0) return -1; wpa_hexdump(MSG_DEBUG, "DPP: Public key hash", bi->pubkey_hash, SHA256_MAC_LEN); addr[0] = (const u8 *) "chirp"; len[0] = 5; addr[1] = data; len[1] = data_len; if (sha256_vector(2, addr, len, bi->pubkey_hash_chirp) < 0) return -1; wpa_hexdump(MSG_DEBUG, "DPP: Public key hash (chirp)", bi->pubkey_hash_chirp, SHA256_MAC_LEN); return 0; } int dpp_get_subject_public_key(struct dpp_bootstrap_info *bi, const u8 *data, size_t data_len) { EVP_PKEY *pkey; const unsigned char *p; int res; X509_PUBKEY *pub = NULL; ASN1_OBJECT *ppkalg; const unsigned char *pk; int ppklen; X509_ALGOR *pa; #if OPENSSL_VERSION_NUMBER < 0x10100000L || \ (defined(LIBRESSL_VERSION_NUMBER) && \ LIBRESSL_VERSION_NUMBER < 0x20800000L) ASN1_OBJECT *pa_oid; #else const ASN1_OBJECT *pa_oid; #endif const void *pval; int ptype; const ASN1_OBJECT *poid; char buf[100]; if (dpp_bi_pubkey_hash(bi, data, data_len) < 0) { wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key"); return -1; } /* DER encoded ASN.1 SubjectPublicKeyInfo * * SubjectPublicKeyInfo ::= SEQUENCE { * algorithm AlgorithmIdentifier, * subjectPublicKey BIT STRING } * * AlgorithmIdentifier ::= SEQUENCE { * algorithm OBJECT IDENTIFIER, * parameters ANY DEFINED BY algorithm OPTIONAL } * * subjectPublicKey = compressed format public key per ANSI X9.63 * algorithm = ecPublicKey (1.2.840.10045.2.1) * parameters = shall be present and shall be OBJECT IDENTIFIER; e.g., * prime256v1 (1.2.840.10045.3.1.7) */ p = data; pkey = d2i_PUBKEY(NULL, &p, data_len); if (!pkey) { wpa_printf(MSG_DEBUG, "DPP: Could not parse URI public-key SubjectPublicKeyInfo"); return -1; } if (EVP_PKEY_type(EVP_PKEY_id(pkey)) != EVP_PKEY_EC) { wpa_printf(MSG_DEBUG, "DPP: SubjectPublicKeyInfo does not describe an EC key"); EVP_PKEY_free(pkey); return -1; } res = X509_PUBKEY_set(&pub, pkey); if (res != 1) { wpa_printf(MSG_DEBUG, "DPP: Could not set pubkey"); goto fail; } res = X509_PUBKEY_get0_param(&ppkalg, &pk, &ppklen, &pa, pub); if (res != 1) { wpa_printf(MSG_DEBUG, "DPP: Could not extract SubjectPublicKeyInfo parameters"); goto fail; } res = OBJ_obj2txt(buf, sizeof(buf), ppkalg, 0); if (res < 0 || (size_t) res >= sizeof(buf)) { wpa_printf(MSG_DEBUG, "DPP: Could not extract SubjectPublicKeyInfo algorithm"); goto fail; } wpa_printf(MSG_DEBUG, "DPP: URI subjectPublicKey algorithm: %s", buf); if (os_strcmp(buf, "id-ecPublicKey") != 0) { wpa_printf(MSG_DEBUG, "DPP: Unsupported SubjectPublicKeyInfo algorithm"); goto fail; } X509_ALGOR_get0(&pa_oid, &ptype, (void *) &pval, pa); if (ptype != V_ASN1_OBJECT) { wpa_printf(MSG_DEBUG, "DPP: SubjectPublicKeyInfo parameters did not contain an OID"); goto fail; } poid = pval; res = OBJ_obj2txt(buf, sizeof(buf), poid, 0); if (res < 0 || (size_t) res >= sizeof(buf)) { wpa_printf(MSG_DEBUG, "DPP: Could not extract SubjectPublicKeyInfo parameters OID"); goto fail; } wpa_printf(MSG_DEBUG, "DPP: URI subjectPublicKey parameters: %s", buf); bi->curve = dpp_get_curve_oid(poid); if (!bi->curve) { wpa_printf(MSG_DEBUG, "DPP: Unsupported SubjectPublicKeyInfo curve: %s", buf); goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: URI subjectPublicKey", pk, ppklen); X509_PUBKEY_free(pub); bi->pubkey = (struct crypto_ec_key *) pkey; return 0; fail: X509_PUBKEY_free(pub); EVP_PKEY_free(pkey); return -1; } static struct wpabuf * dpp_parse_jws_prot_hdr(const struct dpp_curve_params *curve, const u8 *prot_hdr, u16 prot_hdr_len, const EVP_MD **ret_md) { struct json_token *root, *token; struct wpabuf *kid = NULL; root = json_parse((const char *) prot_hdr, prot_hdr_len); if (!root) { wpa_printf(MSG_DEBUG, "DPP: JSON parsing failed for JWS Protected Header"); goto fail; } if (root->type != JSON_OBJECT) { wpa_printf(MSG_DEBUG, "DPP: JWS Protected Header root is not an object"); goto fail; } token = json_get_member(root, "typ"); if (!token || token->type != JSON_STRING) { wpa_printf(MSG_DEBUG, "DPP: No typ string value found"); goto fail; } wpa_printf(MSG_DEBUG, "DPP: JWS Protected Header typ=%s", token->string); if (os_strcmp(token->string, "dppCon") != 0) { wpa_printf(MSG_DEBUG, "DPP: Unsupported JWS Protected Header typ=%s", token->string); goto fail; } token = json_get_member(root, "alg"); if (!token || token->type != JSON_STRING) { wpa_printf(MSG_DEBUG, "DPP: No alg string value found"); goto fail; } wpa_printf(MSG_DEBUG, "DPP: JWS Protected Header alg=%s", token->string); if (os_strcmp(token->string, curve->jws_alg) != 0) { wpa_printf(MSG_DEBUG, "DPP: Unexpected JWS Protected Header alg=%s (expected %s based on C-sign-key)", token->string, curve->jws_alg); goto fail; } if (os_strcmp(token->string, "ES256") == 0 || os_strcmp(token->string, "BS256") == 0) *ret_md = EVP_sha256(); else if (os_strcmp(token->string, "ES384") == 0 || os_strcmp(token->string, "BS384") == 0) *ret_md = EVP_sha384(); else if (os_strcmp(token->string, "ES512") == 0 || os_strcmp(token->string, "BS512") == 0) *ret_md = EVP_sha512(); else *ret_md = NULL; if (!*ret_md) { wpa_printf(MSG_DEBUG, "DPP: Unsupported JWS Protected Header alg=%s", token->string); goto fail; } kid = json_get_member_base64url(root, "kid"); if (!kid) { wpa_printf(MSG_DEBUG, "DPP: No kid string value found"); goto fail; } wpa_hexdump_buf(MSG_DEBUG, "DPP: JWS Protected Header kid (decoded)", kid); fail: json_free(root); return kid; } static int dpp_check_pubkey_match(struct crypto_ec_key *pub, struct wpabuf *r_hash) { struct wpabuf *uncomp; int res; u8 hash[SHA256_MAC_LEN]; const u8 *addr[1]; size_t len[1]; if (wpabuf_len(r_hash) != SHA256_MAC_LEN) return -1; uncomp = dpp_get_pubkey_point(pub, 1); if (!uncomp) return -1; addr[0] = wpabuf_head(uncomp); len[0] = wpabuf_len(uncomp); wpa_hexdump(MSG_DEBUG, "DPP: Uncompressed public key", addr[0], len[0]); res = sha256_vector(1, addr, len, hash); wpabuf_free(uncomp); if (res < 0) return -1; if (os_memcmp(hash, wpabuf_head(r_hash), SHA256_MAC_LEN) != 0) { wpa_printf(MSG_DEBUG, "DPP: Received hash value does not match calculated public key hash value"); wpa_hexdump(MSG_DEBUG, "DPP: Calculated hash", hash, SHA256_MAC_LEN); return -1; } return 0; } enum dpp_status_error dpp_process_signed_connector(struct dpp_signed_connector_info *info, struct crypto_ec_key *csign_pub, const char *connector) { enum dpp_status_error ret = 255; const char *pos, *end, *signed_start, *signed_end; struct wpabuf *kid = NULL; unsigned char *prot_hdr = NULL, *signature = NULL; size_t prot_hdr_len = 0, signature_len = 0; const EVP_MD *sign_md = NULL; unsigned char *der = NULL; int der_len; int res; EVP_MD_CTX *md_ctx = NULL; ECDSA_SIG *sig = NULL; BIGNUM *r = NULL, *s = NULL; const struct dpp_curve_params *curve; const EC_KEY *eckey; const EC_GROUP *group; int nid; eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) csign_pub); if (!eckey) goto fail; group = EC_KEY_get0_group(eckey); if (!group) goto fail; nid = EC_GROUP_get_curve_name(group); curve = dpp_get_curve_nid(nid); if (!curve) goto fail; wpa_printf(MSG_DEBUG, "DPP: C-sign-key group: %s", curve->jwk_crv); os_memset(info, 0, sizeof(*info)); signed_start = pos = connector; end = os_strchr(pos, '.'); if (!end) { wpa_printf(MSG_DEBUG, "DPP: Missing dot(1) in signedConnector"); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } prot_hdr = base64_url_decode(pos, end - pos, &prot_hdr_len); if (!prot_hdr) { wpa_printf(MSG_DEBUG, "DPP: Failed to base64url decode signedConnector JWS Protected Header"); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } wpa_hexdump_ascii(MSG_DEBUG, "DPP: signedConnector - JWS Protected Header", prot_hdr, prot_hdr_len); kid = dpp_parse_jws_prot_hdr(curve, prot_hdr, prot_hdr_len, &sign_md); if (!kid) { ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } if (wpabuf_len(kid) != SHA256_MAC_LEN) { wpa_printf(MSG_DEBUG, "DPP: Unexpected signedConnector JWS Protected Header kid length: %u (expected %u)", (unsigned int) wpabuf_len(kid), SHA256_MAC_LEN); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } pos = end + 1; end = os_strchr(pos, '.'); if (!end) { wpa_printf(MSG_DEBUG, "DPP: Missing dot(2) in signedConnector"); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } signed_end = end - 1; info->payload = base64_url_decode(pos, end - pos, &info->payload_len); if (!info->payload) { wpa_printf(MSG_DEBUG, "DPP: Failed to base64url decode signedConnector JWS Payload"); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } wpa_hexdump_ascii(MSG_DEBUG, "DPP: signedConnector - JWS Payload", info->payload, info->payload_len); pos = end + 1; signature = base64_url_decode(pos, os_strlen(pos), &signature_len); if (!signature) { wpa_printf(MSG_DEBUG, "DPP: Failed to base64url decode signedConnector signature"); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: signedConnector - signature", signature, signature_len); if (dpp_check_pubkey_match(csign_pub, kid) < 0) { ret = DPP_STATUS_NO_MATCH; goto fail; } if (signature_len & 0x01) { wpa_printf(MSG_DEBUG, "DPP: Unexpected signedConnector signature length (%d)", (int) signature_len); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } /* JWS Signature encodes the signature (r,s) as two octet strings. Need * to convert that to DER encoded ECDSA_SIG for OpenSSL EVP routines. */ r = BN_bin2bn(signature, signature_len / 2, NULL); s = BN_bin2bn(signature + signature_len / 2, signature_len / 2, NULL); sig = ECDSA_SIG_new(); if (!r || !s || !sig || ECDSA_SIG_set0(sig, r, s) != 1) goto fail; r = NULL; s = NULL; der_len = i2d_ECDSA_SIG(sig, &der); if (der_len <= 0) { wpa_printf(MSG_DEBUG, "DPP: Could not DER encode signature"); goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: DER encoded signature", der, der_len); md_ctx = EVP_MD_CTX_create(); if (!md_ctx) goto fail; ERR_clear_error(); if (EVP_DigestVerifyInit(md_ctx, NULL, sign_md, NULL, (EVP_PKEY *) csign_pub) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestVerifyInit failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (EVP_DigestVerifyUpdate(md_ctx, signed_start, signed_end - signed_start + 1) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestVerifyUpdate failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } res = EVP_DigestVerifyFinal(md_ctx, der, der_len); if (res != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestVerifyFinal failed (res=%d): %s", res, ERR_error_string(ERR_get_error(), NULL)); ret = DPP_STATUS_INVALID_CONNECTOR; goto fail; } ret = DPP_STATUS_OK; fail: EVP_MD_CTX_destroy(md_ctx); os_free(prot_hdr); wpabuf_free(kid); os_free(signature); ECDSA_SIG_free(sig); BN_free(r); BN_free(s); OPENSSL_free(der); return ret; } enum dpp_status_error dpp_check_signed_connector(struct dpp_signed_connector_info *info, const u8 *csign_key, size_t csign_key_len, const u8 *peer_connector, size_t peer_connector_len) { const unsigned char *p; struct crypto_ec_key *csign; char *signed_connector = NULL; enum dpp_status_error res = DPP_STATUS_INVALID_CONNECTOR; p = csign_key; csign = (struct crypto_ec_key *) d2i_PUBKEY(NULL, &p, csign_key_len); if (!csign) { wpa_printf(MSG_ERROR, "DPP: Failed to parse local C-sign-key information"); goto fail; } wpa_hexdump_ascii(MSG_DEBUG, "DPP: Peer signedConnector", peer_connector, peer_connector_len); signed_connector = os_malloc(peer_connector_len + 1); if (!signed_connector) goto fail; os_memcpy(signed_connector, peer_connector, peer_connector_len); signed_connector[peer_connector_len] = '\0'; res = dpp_process_signed_connector(info, csign, signed_connector); fail: os_free(signed_connector); crypto_ec_key_deinit(csign); return res; } int dpp_gen_r_auth(struct dpp_authentication *auth, u8 *r_auth) { struct wpabuf *pix, *prx, *bix, *brx; const u8 *addr[7]; size_t len[7]; size_t i, num_elem = 0; size_t nonce_len; u8 zero = 0; int res = -1; /* R-auth = H(I-nonce | R-nonce | PI.x | PR.x | [BI.x |] BR.x | 0) */ nonce_len = auth->curve->nonce_len; if (auth->initiator) { pix = dpp_get_pubkey_point(auth->own_protocol_key, 0); prx = dpp_get_pubkey_point(auth->peer_protocol_key, 0); if (auth->own_bi) bix = dpp_get_pubkey_point(auth->own_bi->pubkey, 0); else bix = NULL; brx = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0); } else { pix = dpp_get_pubkey_point(auth->peer_protocol_key, 0); prx = dpp_get_pubkey_point(auth->own_protocol_key, 0); if (auth->peer_bi) bix = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0); else bix = NULL; brx = dpp_get_pubkey_point(auth->own_bi->pubkey, 0); } if (!pix || !prx || !brx) goto fail; addr[num_elem] = auth->i_nonce; len[num_elem] = nonce_len; num_elem++; addr[num_elem] = auth->r_nonce; len[num_elem] = nonce_len; num_elem++; addr[num_elem] = wpabuf_head(pix); len[num_elem] = wpabuf_len(pix) / 2; num_elem++; addr[num_elem] = wpabuf_head(prx); len[num_elem] = wpabuf_len(prx) / 2; num_elem++; if (bix) { addr[num_elem] = wpabuf_head(bix); len[num_elem] = wpabuf_len(bix) / 2; num_elem++; } addr[num_elem] = wpabuf_head(brx); len[num_elem] = wpabuf_len(brx) / 2; num_elem++; addr[num_elem] = &zero; len[num_elem] = 1; num_elem++; wpa_printf(MSG_DEBUG, "DPP: R-auth hash components"); for (i = 0; i < num_elem; i++) wpa_hexdump(MSG_DEBUG, "DPP: hash component", addr[i], len[i]); res = dpp_hash_vector(auth->curve, num_elem, addr, len, r_auth); if (res == 0) wpa_hexdump(MSG_DEBUG, "DPP: R-auth", r_auth, auth->curve->hash_len); fail: wpabuf_free(pix); wpabuf_free(prx); wpabuf_free(bix); wpabuf_free(brx); return res; } int dpp_gen_i_auth(struct dpp_authentication *auth, u8 *i_auth) { struct wpabuf *pix = NULL, *prx = NULL, *bix = NULL, *brx = NULL; const u8 *addr[7]; size_t len[7]; size_t i, num_elem = 0; size_t nonce_len; u8 one = 1; int res = -1; /* I-auth = H(R-nonce | I-nonce | PR.x | PI.x | BR.x | [BI.x |] 1) */ nonce_len = auth->curve->nonce_len; if (auth->initiator) { pix = dpp_get_pubkey_point(auth->own_protocol_key, 0); prx = dpp_get_pubkey_point(auth->peer_protocol_key, 0); if (auth->own_bi) bix = dpp_get_pubkey_point(auth->own_bi->pubkey, 0); else bix = NULL; if (!auth->peer_bi) goto fail; brx = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0); } else { pix = dpp_get_pubkey_point(auth->peer_protocol_key, 0); prx = dpp_get_pubkey_point(auth->own_protocol_key, 0); if (auth->peer_bi) bix = dpp_get_pubkey_point(auth->peer_bi->pubkey, 0); else bix = NULL; if (!auth->own_bi) goto fail; brx = dpp_get_pubkey_point(auth->own_bi->pubkey, 0); } if (!pix || !prx || !brx) goto fail; addr[num_elem] = auth->r_nonce; len[num_elem] = nonce_len; num_elem++; addr[num_elem] = auth->i_nonce; len[num_elem] = nonce_len; num_elem++; addr[num_elem] = wpabuf_head(prx); len[num_elem] = wpabuf_len(prx) / 2; num_elem++; addr[num_elem] = wpabuf_head(pix); len[num_elem] = wpabuf_len(pix) / 2; num_elem++; addr[num_elem] = wpabuf_head(brx); len[num_elem] = wpabuf_len(brx) / 2; num_elem++; if (bix) { addr[num_elem] = wpabuf_head(bix); len[num_elem] = wpabuf_len(bix) / 2; num_elem++; } addr[num_elem] = &one; len[num_elem] = 1; num_elem++; wpa_printf(MSG_DEBUG, "DPP: I-auth hash components"); for (i = 0; i < num_elem; i++) wpa_hexdump(MSG_DEBUG, "DPP: hash component", addr[i], len[i]); res = dpp_hash_vector(auth->curve, num_elem, addr, len, i_auth); if (res == 0) wpa_hexdump(MSG_DEBUG, "DPP: I-auth", i_auth, auth->curve->hash_len); fail: wpabuf_free(pix); wpabuf_free(prx); wpabuf_free(bix); wpabuf_free(brx); return res; } int dpp_auth_derive_l_responder(struct dpp_authentication *auth) { const EC_GROUP *group; EC_POINT *l = NULL; const EC_KEY *BI, *bR, *pR; const EC_POINT *BI_point; BN_CTX *bnctx; BIGNUM *lx, *sum, *q; const BIGNUM *bR_bn, *pR_bn; int ret = -1; /* L = ((bR + pR) modulo q) * BI */ bnctx = BN_CTX_new(); sum = BN_new(); q = BN_new(); lx = BN_new(); if (!bnctx || !sum || !q || !lx) goto fail; BI = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->peer_bi->pubkey); if (!BI) goto fail; BI_point = EC_KEY_get0_public_key(BI); group = EC_KEY_get0_group(BI); if (!group) goto fail; bR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->own_bi->pubkey); pR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->own_protocol_key); if (!bR || !pR) goto fail; bR_bn = EC_KEY_get0_private_key(bR); pR_bn = EC_KEY_get0_private_key(pR); if (!bR_bn || !pR_bn) goto fail; if (EC_GROUP_get_order(group, q, bnctx) != 1 || BN_mod_add(sum, bR_bn, pR_bn, q, bnctx) != 1) goto fail; l = EC_POINT_new(group); if (!l || EC_POINT_mul(group, l, NULL, BI_point, sum, bnctx) != 1 || EC_POINT_get_affine_coordinates_GFp(group, l, lx, NULL, bnctx) != 1) { wpa_printf(MSG_ERROR, "OpenSSL: failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (dpp_bn2bin_pad(lx, auth->Lx, auth->secret_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: L.x", auth->Lx, auth->secret_len); auth->Lx_len = auth->secret_len; ret = 0; fail: EC_POINT_clear_free(l); BN_clear_free(lx); BN_clear_free(sum); BN_free(q); BN_CTX_free(bnctx); return ret; } int dpp_auth_derive_l_initiator(struct dpp_authentication *auth) { const EC_GROUP *group; EC_POINT *l = NULL, *sum = NULL; const EC_KEY *bI, *BR, *PR; const EC_POINT *BR_point, *PR_point; BN_CTX *bnctx; BIGNUM *lx; const BIGNUM *bI_bn; int ret = -1; /* L = bI * (BR + PR) */ bnctx = BN_CTX_new(); lx = BN_new(); if (!bnctx || !lx) goto fail; BR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->peer_bi->pubkey); PR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->peer_protocol_key); if (!BR || !PR) goto fail; BR_point = EC_KEY_get0_public_key(BR); PR_point = EC_KEY_get0_public_key(PR); bI = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->own_bi->pubkey); if (!bI) goto fail; group = EC_KEY_get0_group(bI); bI_bn = EC_KEY_get0_private_key(bI); if (!group || !bI_bn) goto fail; sum = EC_POINT_new(group); l = EC_POINT_new(group); if (!sum || !l || EC_POINT_add(group, sum, BR_point, PR_point, bnctx) != 1 || EC_POINT_mul(group, l, NULL, sum, bI_bn, bnctx) != 1 || EC_POINT_get_affine_coordinates_GFp(group, l, lx, NULL, bnctx) != 1) { wpa_printf(MSG_ERROR, "OpenSSL: failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (dpp_bn2bin_pad(lx, auth->Lx, auth->secret_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: L.x", auth->Lx, auth->secret_len); auth->Lx_len = auth->secret_len; ret = 0; fail: EC_POINT_clear_free(l); EC_POINT_clear_free(sum); BN_clear_free(lx); BN_CTX_free(bnctx); return ret; } int dpp_derive_pmk(const u8 *Nx, size_t Nx_len, u8 *pmk, unsigned int hash_len) { u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN]; const char *info = "DPP PMK"; int res; /* PMK = HKDF(<>, "DPP PMK", N.x) */ /* HKDF-Extract(<>, N.x) */ os_memset(salt, 0, hash_len); if (dpp_hmac(hash_len, salt, hash_len, Nx, Nx_len, prk) < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM=N.x)", prk, hash_len); /* HKDF-Expand(PRK, info, L) */ res = dpp_hkdf_expand(hash_len, prk, hash_len, info, pmk, hash_len); os_memset(prk, 0, hash_len); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: PMK = HKDF-Expand(PRK, info, L)", pmk, hash_len); return 0; } int dpp_derive_pmkid(const struct dpp_curve_params *curve, struct crypto_ec_key *own_key, struct crypto_ec_key *peer_key, u8 *pmkid) { struct wpabuf *nkx, *pkx; int ret = -1, res; const u8 *addr[2]; size_t len[2]; u8 hash[SHA256_MAC_LEN]; /* PMKID = Truncate-128(H(min(NK.x, PK.x) | max(NK.x, PK.x))) */ nkx = dpp_get_pubkey_point(own_key, 0); pkx = dpp_get_pubkey_point(peer_key, 0); if (!nkx || !pkx) goto fail; addr[0] = wpabuf_head(nkx); len[0] = wpabuf_len(nkx) / 2; addr[1] = wpabuf_head(pkx); len[1] = wpabuf_len(pkx) / 2; if (len[0] != len[1]) goto fail; if (os_memcmp(addr[0], addr[1], len[0]) > 0) { addr[0] = wpabuf_head(pkx); addr[1] = wpabuf_head(nkx); } wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 1", addr[0], len[0]); wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash payload 2", addr[1], len[1]); res = sha256_vector(2, addr, len, hash); if (res < 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: PMKID hash output", hash, SHA256_MAC_LEN); os_memcpy(pmkid, hash, PMKID_LEN); wpa_hexdump(MSG_DEBUG, "DPP: PMKID", pmkid, PMKID_LEN); ret = 0; fail: wpabuf_free(nkx); wpabuf_free(pkx); return ret; } /* Role-specific elements for PKEX */ /* NIST P-256 */ static const u8 pkex_init_x_p256[32] = { 0x56, 0x26, 0x12, 0xcf, 0x36, 0x48, 0xfe, 0x0b, 0x07, 0x04, 0xbb, 0x12, 0x22, 0x50, 0xb2, 0x54, 0xb1, 0x94, 0x64, 0x7e, 0x54, 0xce, 0x08, 0x07, 0x2e, 0xec, 0xca, 0x74, 0x5b, 0x61, 0x2d, 0x25 }; static const u8 pkex_init_y_p256[32] = { 0x3e, 0x44, 0xc7, 0xc9, 0x8c, 0x1c, 0xa1, 0x0b, 0x20, 0x09, 0x93, 0xb2, 0xfd, 0xe5, 0x69, 0xdc, 0x75, 0xbc, 0xad, 0x33, 0xc1, 0xe7, 0xc6, 0x45, 0x4d, 0x10, 0x1e, 0x6a, 0x3d, 0x84, 0x3c, 0xa4 }; static const u8 pkex_resp_x_p256[32] = { 0x1e, 0xa4, 0x8a, 0xb1, 0xa4, 0xe8, 0x42, 0x39, 0xad, 0x73, 0x07, 0xf2, 0x34, 0xdf, 0x57, 0x4f, 0xc0, 0x9d, 0x54, 0xbe, 0x36, 0x1b, 0x31, 0x0f, 0x59, 0x91, 0x52, 0x33, 0xac, 0x19, 0x9d, 0x76 }; static const u8 pkex_resp_y_p256[32] = { 0xd9, 0xfb, 0xf6, 0xb9, 0xf5, 0xfa, 0xdf, 0x19, 0x58, 0xd8, 0x3e, 0xc9, 0x89, 0x7a, 0x35, 0xc1, 0xbd, 0xe9, 0x0b, 0x77, 0x7a, 0xcb, 0x91, 0x2a, 0xe8, 0x21, 0x3f, 0x47, 0x52, 0x02, 0x4d, 0x67 }; /* NIST P-384 */ static const u8 pkex_init_x_p384[48] = { 0x95, 0x3f, 0x42, 0x9e, 0x50, 0x7f, 0xf9, 0xaa, 0xac, 0x1a, 0xf2, 0x85, 0x2e, 0x64, 0x91, 0x68, 0x64, 0xc4, 0x3c, 0xb7, 0x5c, 0xf8, 0xc9, 0x53, 0x6e, 0x58, 0x4c, 0x7f, 0xc4, 0x64, 0x61, 0xac, 0x51, 0x8a, 0x6f, 0xfe, 0xab, 0x74, 0xe6, 0x12, 0x81, 0xac, 0x38, 0x5d, 0x41, 0xe6, 0xb9, 0xa3 }; static const u8 pkex_init_y_p384[48] = { 0x76, 0x2f, 0x68, 0x84, 0xa6, 0xb0, 0x59, 0x29, 0x83, 0xa2, 0x6c, 0xa4, 0x6c, 0x3b, 0xf8, 0x56, 0x76, 0x11, 0x2a, 0x32, 0x90, 0xbd, 0x07, 0xc7, 0x37, 0x39, 0x9d, 0xdb, 0x96, 0xf3, 0x2b, 0xb6, 0x27, 0xbb, 0x29, 0x3c, 0x17, 0x33, 0x9d, 0x94, 0xc3, 0xda, 0xac, 0x46, 0xb0, 0x8e, 0x07, 0x18 }; static const u8 pkex_resp_x_p384[48] = { 0xad, 0xbe, 0xd7, 0x1d, 0x3a, 0x71, 0x64, 0x98, 0x5f, 0xb4, 0xd6, 0x4b, 0x50, 0xd0, 0x84, 0x97, 0x4b, 0x7e, 0x57, 0x70, 0xd2, 0xd9, 0xf4, 0x92, 0x2a, 0x3f, 0xce, 0x99, 0xc5, 0x77, 0x33, 0x44, 0x14, 0x56, 0x92, 0xcb, 0xae, 0x46, 0x64, 0xdf, 0xe0, 0xbb, 0xd7, 0xb1, 0x29, 0x20, 0x72, 0xdf }; static const u8 pkex_resp_y_p384[48] = { 0xab, 0xa7, 0xdf, 0x52, 0xaa, 0xe2, 0x35, 0x0c, 0xe3, 0x75, 0x32, 0xe6, 0xbf, 0x06, 0xc8, 0x7c, 0x38, 0x29, 0x4c, 0xec, 0x82, 0xac, 0xd7, 0xa3, 0x09, 0xd2, 0x0e, 0x22, 0x5a, 0x74, 0x52, 0xa1, 0x7e, 0x54, 0x4e, 0xfe, 0xc6, 0x29, 0x33, 0x63, 0x15, 0xe1, 0x7b, 0xe3, 0x40, 0x1c, 0xca, 0x06 }; /* NIST P-521 */ static const u8 pkex_init_x_p521[66] = { 0x00, 0x16, 0x20, 0x45, 0x19, 0x50, 0x95, 0x23, 0x0d, 0x24, 0xbe, 0x00, 0x87, 0xdc, 0xfa, 0xf0, 0x58, 0x9a, 0x01, 0x60, 0x07, 0x7a, 0xca, 0x76, 0x01, 0xab, 0x2d, 0x5a, 0x46, 0xcd, 0x2c, 0xb5, 0x11, 0x9a, 0xff, 0xaa, 0x48, 0x04, 0x91, 0x38, 0xcf, 0x86, 0xfc, 0xa4, 0xa5, 0x0f, 0x47, 0x01, 0x80, 0x1b, 0x30, 0xa3, 0xae, 0xe8, 0x1c, 0x2e, 0xea, 0xcc, 0xf0, 0x03, 0x9f, 0x77, 0x4c, 0x8d, 0x97, 0x76 }; static const u8 pkex_init_y_p521[66] = { 0x00, 0xb3, 0x8e, 0x02, 0xe4, 0x2a, 0x63, 0x59, 0x12, 0xc6, 0x10, 0xba, 0x3a, 0xf9, 0x02, 0x99, 0x3f, 0x14, 0xf0, 0x40, 0xde, 0x5c, 0xc9, 0x8b, 0x02, 0x55, 0xfa, 0x91, 0xb1, 0xcc, 0x6a, 0xbd, 0xe5, 0x62, 0xc0, 0xc5, 0xe3, 0xa1, 0x57, 0x9f, 0x08, 0x1a, 0xa6, 0xe2, 0xf8, 0x55, 0x90, 0xbf, 0xf5, 0xa6, 0xc3, 0xd8, 0x52, 0x1f, 0xb7, 0x02, 0x2e, 0x7c, 0xc8, 0xb3, 0x20, 0x1e, 0x79, 0x8d, 0x03, 0xa8 }; static const u8 pkex_resp_x_p521[66] = { 0x00, 0x79, 0xe4, 0x4d, 0x6b, 0x5e, 0x12, 0x0a, 0x18, 0x2c, 0xb3, 0x05, 0x77, 0x0f, 0xc3, 0x44, 0x1a, 0xcd, 0x78, 0x46, 0x14, 0xee, 0x46, 0x3f, 0xab, 0xc9, 0x59, 0x7c, 0x85, 0xa0, 0xc2, 0xfb, 0x02, 0x32, 0x99, 0xde, 0x5d, 0xe1, 0x0d, 0x48, 0x2d, 0x71, 0x7d, 0x8d, 0x3f, 0x61, 0x67, 0x9e, 0x2b, 0x8b, 0x12, 0xde, 0x10, 0x21, 0x55, 0x0a, 0x5b, 0x2d, 0xe8, 0x05, 0x09, 0xf6, 0x20, 0x97, 0x84, 0xb4 }; static const u8 pkex_resp_y_p521[66] = { 0x00, 0x46, 0x63, 0x39, 0xbe, 0xcd, 0xa4, 0x2d, 0xca, 0x27, 0x74, 0xd4, 0x1b, 0x91, 0x33, 0x20, 0x83, 0xc7, 0x3b, 0xa4, 0x09, 0x8b, 0x8e, 0xa3, 0x88, 0xe9, 0x75, 0x7f, 0x56, 0x7b, 0x38, 0x84, 0x62, 0x02, 0x7c, 0x90, 0x51, 0x07, 0xdb, 0xe9, 0xd0, 0xde, 0xda, 0x9a, 0x5d, 0xe5, 0x94, 0xd2, 0xcf, 0x9d, 0x4c, 0x33, 0x91, 0xa6, 0xc3, 0x80, 0xa7, 0x6e, 0x7e, 0x8d, 0xf8, 0x73, 0x6e, 0x53, 0xce, 0xe1 }; /* Brainpool P-256r1 */ static const u8 pkex_init_x_bp_p256r1[32] = { 0x46, 0x98, 0x18, 0x6c, 0x27, 0xcd, 0x4b, 0x10, 0x7d, 0x55, 0xa3, 0xdd, 0x89, 0x1f, 0x9f, 0xca, 0xc7, 0x42, 0x5b, 0x8a, 0x23, 0xed, 0xf8, 0x75, 0xac, 0xc7, 0xe9, 0x8d, 0xc2, 0x6f, 0xec, 0xd8 }; static const u8 pkex_init_y_bp_p256r1[32] = { 0x93, 0xca, 0xef, 0xa9, 0x66, 0x3e, 0x87, 0xcd, 0x52, 0x6e, 0x54, 0x13, 0xef, 0x31, 0x67, 0x30, 0x15, 0x13, 0x9d, 0x6d, 0xc0, 0x95, 0x32, 0xbe, 0x4f, 0xab, 0x5d, 0xf7, 0xbf, 0x5e, 0xaa, 0x0b }; static const u8 pkex_resp_x_bp_p256r1[32] = { 0x90, 0x18, 0x84, 0xc9, 0xdc, 0xcc, 0xb5, 0x2f, 0x4a, 0x3f, 0x4f, 0x18, 0x0a, 0x22, 0x56, 0x6a, 0xa9, 0xef, 0xd4, 0xe6, 0xc3, 0x53, 0xc2, 0x1a, 0x23, 0x54, 0xdd, 0x08, 0x7e, 0x10, 0xd8, 0xe3 }; static const u8 pkex_resp_y_bp_p256r1[32] = { 0x2a, 0xfa, 0x98, 0x9b, 0xe3, 0xda, 0x30, 0xfd, 0x32, 0x28, 0xcb, 0x66, 0xfb, 0x40, 0x7f, 0xf2, 0xb2, 0x25, 0x80, 0x82, 0x44, 0x85, 0x13, 0x7e, 0x4b, 0xb5, 0x06, 0xc0, 0x03, 0x69, 0x23, 0x64 }; /* Brainpool P-384r1 */ static const u8 pkex_init_x_bp_p384r1[48] = { 0x0a, 0x2c, 0xeb, 0x49, 0x5e, 0xb7, 0x23, 0xbd, 0x20, 0x5b, 0xe0, 0x49, 0xdf, 0xcf, 0xcf, 0x19, 0x37, 0x36, 0xe1, 0x2f, 0x59, 0xdb, 0x07, 0x06, 0xb5, 0xeb, 0x2d, 0xae, 0xc2, 0xb2, 0x38, 0x62, 0xa6, 0x73, 0x09, 0xa0, 0x6c, 0x0a, 0xa2, 0x30, 0x99, 0xeb, 0xf7, 0x1e, 0x47, 0xb9, 0x5e, 0xbe }; static const u8 pkex_init_y_bp_p384r1[48] = { 0x54, 0x76, 0x61, 0x65, 0x75, 0x5a, 0x2f, 0x99, 0x39, 0x73, 0xca, 0x6c, 0xf9, 0xf7, 0x12, 0x86, 0x54, 0xd5, 0xd4, 0xad, 0x45, 0x7b, 0xbf, 0x32, 0xee, 0x62, 0x8b, 0x9f, 0x52, 0xe8, 0xa0, 0xc9, 0xb7, 0x9d, 0xd1, 0x09, 0xb4, 0x79, 0x1c, 0x3e, 0x1a, 0xbf, 0x21, 0x45, 0x66, 0x6b, 0x02, 0x52 }; static const u8 pkex_resp_x_bp_p384r1[48] = { 0x03, 0xa2, 0x57, 0xef, 0xe8, 0x51, 0x21, 0xa0, 0xc8, 0x9e, 0x21, 0x02, 0xb5, 0x9a, 0x36, 0x25, 0x74, 0x22, 0xd1, 0xf2, 0x1b, 0xa8, 0x9a, 0x9b, 0x97, 0xbc, 0x5a, 0xeb, 0x26, 0x15, 0x09, 0x71, 0x77, 0x59, 0xec, 0x8b, 0xb7, 0xe1, 0xe8, 0xce, 0x65, 0xb8, 0xaf, 0xf8, 0x80, 0xae, 0x74, 0x6c }; static const u8 pkex_resp_y_bp_p384r1[48] = { 0x2f, 0xd9, 0x6a, 0xc7, 0x3e, 0xec, 0x76, 0x65, 0x2d, 0x38, 0x7f, 0xec, 0x63, 0x26, 0x3f, 0x04, 0xd8, 0x4e, 0xff, 0xe1, 0x0a, 0x51, 0x74, 0x70, 0xe5, 0x46, 0x63, 0x7f, 0x5c, 0xc0, 0xd1, 0x7c, 0xfb, 0x2f, 0xea, 0xe2, 0xd8, 0x0f, 0x84, 0xcb, 0xe9, 0x39, 0x5c, 0x64, 0xfe, 0xcb, 0x2f, 0xf1 }; /* Brainpool P-512r1 */ static const u8 pkex_init_x_bp_p512r1[64] = { 0x4c, 0xe9, 0xb6, 0x1c, 0xe2, 0x00, 0x3c, 0x9c, 0xa9, 0xc8, 0x56, 0x52, 0xaf, 0x87, 0x3e, 0x51, 0x9c, 0xbb, 0x15, 0x31, 0x1e, 0xc1, 0x05, 0xfc, 0x7c, 0x77, 0xd7, 0x37, 0x61, 0x27, 0xd0, 0x95, 0x98, 0xee, 0x5d, 0xa4, 0x3d, 0x09, 0xdb, 0x3d, 0xfa, 0x89, 0x9e, 0x7f, 0xa6, 0xa6, 0x9c, 0xff, 0x83, 0x5c, 0x21, 0x6c, 0x3e, 0xf2, 0xfe, 0xdc, 0x63, 0xe4, 0xd1, 0x0e, 0x75, 0x45, 0x69, 0x0f }; static const u8 pkex_init_y_bp_p512r1[64] = { 0x50, 0xb5, 0x9b, 0xfa, 0x45, 0x67, 0x75, 0x94, 0x44, 0xe7, 0x68, 0xb0, 0xeb, 0x3e, 0xb3, 0xb8, 0xf9, 0x99, 0x05, 0xef, 0xae, 0x6c, 0xbc, 0xe3, 0xe1, 0xd2, 0x51, 0x54, 0xdf, 0x59, 0xd4, 0x45, 0x41, 0x3a, 0xa8, 0x0b, 0x76, 0x32, 0x44, 0x0e, 0x07, 0x60, 0x3a, 0x6e, 0xbe, 0xfe, 0xe0, 0x58, 0x52, 0xa0, 0xaa, 0x8b, 0xd8, 0x5b, 0xf2, 0x71, 0x11, 0x9a, 0x9e, 0x8f, 0x1a, 0xd1, 0xc9, 0x99 }; static const u8 pkex_resp_x_bp_p512r1[64] = { 0x2a, 0x60, 0x32, 0x27, 0xa1, 0xe6, 0x94, 0x72, 0x1c, 0x48, 0xbe, 0xc5, 0x77, 0x14, 0x30, 0x76, 0xe4, 0xbf, 0xf7, 0x7b, 0xc5, 0xfd, 0xdf, 0x19, 0x1e, 0x0f, 0xdf, 0x1c, 0x40, 0xfa, 0x34, 0x9e, 0x1f, 0x42, 0x24, 0xa3, 0x2c, 0xd5, 0xc7, 0xc9, 0x7b, 0x47, 0x78, 0x96, 0xf1, 0x37, 0x0e, 0x88, 0xcb, 0xa6, 0x52, 0x29, 0xd7, 0xa8, 0x38, 0x29, 0x8e, 0x6e, 0x23, 0x47, 0xd4, 0x4b, 0x70, 0x3e }; static const u8 pkex_resp_y_bp_p512r1[64] = { 0x80, 0x1f, 0x43, 0xd2, 0x17, 0x35, 0xec, 0x81, 0xd9, 0x4b, 0xdc, 0x81, 0x19, 0xd9, 0x5f, 0x68, 0x16, 0x84, 0xfe, 0x63, 0x4b, 0x8d, 0x5d, 0xaa, 0x88, 0x4a, 0x47, 0x48, 0xd4, 0xea, 0xab, 0x7d, 0x6a, 0xbf, 0xe1, 0x28, 0x99, 0x6a, 0x87, 0x1c, 0x30, 0xb4, 0x44, 0x2d, 0x75, 0xac, 0x35, 0x09, 0x73, 0x24, 0x3d, 0xb4, 0x43, 0xb1, 0xc1, 0x56, 0x56, 0xad, 0x30, 0x87, 0xf4, 0xc3, 0x00, 0xc7 }; static struct crypto_ec_key * dpp_pkex_get_role_elem(const struct dpp_curve_params *curve, int init) { EC_GROUP *group; size_t len = curve->prime_len; const u8 *x, *y; struct crypto_ec_key *res; switch (curve->ike_group) { case 19: x = init ? pkex_init_x_p256 : pkex_resp_x_p256; y = init ? pkex_init_y_p256 : pkex_resp_y_p256; break; case 20: x = init ? pkex_init_x_p384 : pkex_resp_x_p384; y = init ? pkex_init_y_p384 : pkex_resp_y_p384; break; case 21: x = init ? pkex_init_x_p521 : pkex_resp_x_p521; y = init ? pkex_init_y_p521 : pkex_resp_y_p521; break; case 28: x = init ? pkex_init_x_bp_p256r1 : pkex_resp_x_bp_p256r1; y = init ? pkex_init_y_bp_p256r1 : pkex_resp_y_bp_p256r1; break; case 29: x = init ? pkex_init_x_bp_p384r1 : pkex_resp_x_bp_p384r1; y = init ? pkex_init_y_bp_p384r1 : pkex_resp_y_bp_p384r1; break; case 30: x = init ? pkex_init_x_bp_p512r1 : pkex_resp_x_bp_p512r1; y = init ? pkex_init_y_bp_p512r1 : pkex_resp_y_bp_p512r1; break; default: return NULL; } group = EC_GROUP_new_by_curve_name(OBJ_txt2nid(curve->name)); if (!group) return NULL; res = dpp_set_pubkey_point_group(group, x, y, len); EC_GROUP_free(group); return res; } EC_POINT * dpp_pkex_derive_Qi(const struct dpp_curve_params *curve, const u8 *mac_init, const char *code, const char *identifier, BN_CTX *bnctx, EC_GROUP **ret_group) { u8 hash[DPP_MAX_HASH_LEN]; const u8 *addr[3]; size_t len[3]; unsigned int num_elem = 0; EC_POINT *Qi = NULL; struct crypto_ec_key *Pi = NULL; const EC_KEY *Pi_ec; const EC_POINT *Pi_point; BIGNUM *hash_bn = NULL; const EC_GROUP *group = NULL; EC_GROUP *group2 = NULL; /* Qi = H(MAC-Initiator | [identifier |] code) * Pi */ wpa_printf(MSG_DEBUG, "DPP: MAC-Initiator: " MACSTR, MAC2STR(mac_init)); addr[num_elem] = mac_init; len[num_elem] = ETH_ALEN; num_elem++; if (identifier) { wpa_printf(MSG_DEBUG, "DPP: code identifier: %s", identifier); addr[num_elem] = (const u8 *) identifier; len[num_elem] = os_strlen(identifier); num_elem++; } wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: code", code, os_strlen(code)); addr[num_elem] = (const u8 *) code; len[num_elem] = os_strlen(code); num_elem++; if (dpp_hash_vector(curve, num_elem, addr, len, hash) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: H(MAC-Initiator | [identifier |] code)", hash, curve->hash_len); Pi = dpp_pkex_get_role_elem(curve, 1); if (!Pi) goto fail; dpp_debug_print_key("DPP: Pi", Pi); Pi_ec = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) Pi); if (!Pi_ec) goto fail; Pi_point = EC_KEY_get0_public_key(Pi_ec); group = EC_KEY_get0_group(Pi_ec); if (!group) goto fail; group2 = EC_GROUP_dup(group); if (!group2) goto fail; Qi = EC_POINT_new(group2); if (!Qi) { EC_GROUP_free(group2); goto fail; } hash_bn = BN_bin2bn(hash, curve->hash_len, NULL); if (!hash_bn || EC_POINT_mul(group2, Qi, NULL, Pi_point, hash_bn, bnctx) != 1) goto fail; if (EC_POINT_is_at_infinity(group, Qi)) { wpa_printf(MSG_INFO, "DPP: Qi is the point-at-infinity"); goto fail; } dpp_debug_print_point("DPP: Qi", group, Qi); out: crypto_ec_key_deinit(Pi); BN_clear_free(hash_bn); if (ret_group && Qi) *ret_group = group2; else EC_GROUP_free(group2); return Qi; fail: EC_POINT_free(Qi); Qi = NULL; goto out; } EC_POINT * dpp_pkex_derive_Qr(const struct dpp_curve_params *curve, const u8 *mac_resp, const char *code, const char *identifier, BN_CTX *bnctx, EC_GROUP **ret_group) { u8 hash[DPP_MAX_HASH_LEN]; const u8 *addr[3]; size_t len[3]; unsigned int num_elem = 0; EC_POINT *Qr = NULL; struct crypto_ec_key *Pr = NULL; const EC_KEY *Pr_ec; const EC_POINT *Pr_point; BIGNUM *hash_bn = NULL; const EC_GROUP *group = NULL; EC_GROUP *group2 = NULL; /* Qr = H(MAC-Responder | | [identifier | ] code) * Pr */ wpa_printf(MSG_DEBUG, "DPP: MAC-Responder: " MACSTR, MAC2STR(mac_resp)); addr[num_elem] = mac_resp; len[num_elem] = ETH_ALEN; num_elem++; if (identifier) { wpa_printf(MSG_DEBUG, "DPP: code identifier: %s", identifier); addr[num_elem] = (const u8 *) identifier; len[num_elem] = os_strlen(identifier); num_elem++; } wpa_hexdump_ascii_key(MSG_DEBUG, "DPP: code", code, os_strlen(code)); addr[num_elem] = (const u8 *) code; len[num_elem] = os_strlen(code); num_elem++; if (dpp_hash_vector(curve, num_elem, addr, len, hash) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: H(MAC-Responder | [identifier |] code)", hash, curve->hash_len); Pr = dpp_pkex_get_role_elem(curve, 0); if (!Pr) goto fail; dpp_debug_print_key("DPP: Pr", Pr); Pr_ec = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) Pr); if (!Pr_ec) goto fail; Pr_point = EC_KEY_get0_public_key(Pr_ec); group = EC_KEY_get0_group(Pr_ec); if (!group) goto fail; group2 = EC_GROUP_dup(group); if (!group2) goto fail; Qr = EC_POINT_new(group2); if (!Qr) { EC_GROUP_free(group2); goto fail; } hash_bn = BN_bin2bn(hash, curve->hash_len, NULL); if (!hash_bn || EC_POINT_mul(group2, Qr, NULL, Pr_point, hash_bn, bnctx) != 1) goto fail; if (EC_POINT_is_at_infinity(group, Qr)) { wpa_printf(MSG_INFO, "DPP: Qr is the point-at-infinity"); goto fail; } dpp_debug_print_point("DPP: Qr", group, Qr); out: crypto_ec_key_deinit(Pr); BN_clear_free(hash_bn); if (ret_group && Qr) *ret_group = group2; else EC_GROUP_free(group2); return Qr; fail: EC_POINT_free(Qr); Qr = NULL; goto out; } int dpp_pkex_derive_z(const u8 *mac_init, const u8 *mac_resp, const u8 *Mx, size_t Mx_len, const u8 *Nx, size_t Nx_len, const char *code, const u8 *Kx, size_t Kx_len, u8 *z, unsigned int hash_len) { u8 salt[DPP_MAX_HASH_LEN], prk[DPP_MAX_HASH_LEN]; int res; u8 *info, *pos; size_t info_len; /* z = HKDF(<>, MAC-Initiator | MAC-Responder | M.x | N.x | code, K.x) */ /* HKDF-Extract(<>, IKM=K.x) */ os_memset(salt, 0, hash_len); if (dpp_hmac(hash_len, salt, hash_len, Kx, Kx_len, prk) < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK = HKDF-Extract(<>, IKM)", prk, hash_len); info_len = 2 * ETH_ALEN + Mx_len + Nx_len + os_strlen(code); info = os_malloc(info_len); if (!info) return -1; pos = info; os_memcpy(pos, mac_init, ETH_ALEN); pos += ETH_ALEN; os_memcpy(pos, mac_resp, ETH_ALEN); pos += ETH_ALEN; os_memcpy(pos, Mx, Mx_len); pos += Mx_len; os_memcpy(pos, Nx, Nx_len); pos += Nx_len; os_memcpy(pos, code, os_strlen(code)); /* HKDF-Expand(PRK, info, L) */ if (hash_len == 32) res = hmac_sha256_kdf(prk, hash_len, NULL, info, info_len, z, hash_len); else if (hash_len == 48) res = hmac_sha384_kdf(prk, hash_len, NULL, info, info_len, z, hash_len); else if (hash_len == 64) res = hmac_sha512_kdf(prk, hash_len, NULL, info, info_len, z, hash_len); else res = -1; os_free(info); os_memset(prk, 0, hash_len); if (res < 0) return -1; wpa_hexdump_key(MSG_DEBUG, "DPP: z = HKDF-Expand(PRK, info, L)", z, hash_len); return 0; } int dpp_reconfig_derive_ke_responder(struct dpp_authentication *auth, const u8 *net_access_key, size_t net_access_key_len, struct json_token *peer_net_access_key) { BN_CTX *bnctx = NULL; struct crypto_ec_key *own_key = NULL, *peer_key = NULL; BIGNUM *sum = NULL, *q = NULL, *mx = NULL; EC_POINT *m = NULL; const EC_KEY *cR, *pR; const EC_GROUP *group; const BIGNUM *cR_bn, *pR_bn; const EC_POINT *CI_point; const EC_KEY *CI; u8 Mx[DPP_MAX_SHARED_SECRET_LEN]; u8 prk[DPP_MAX_HASH_LEN]; const struct dpp_curve_params *curve; int res = -1; u8 nonces[2 * DPP_MAX_NONCE_LEN]; own_key = dpp_set_keypair(&auth->curve, net_access_key, net_access_key_len); if (!own_key) { dpp_auth_fail(auth, "Failed to parse own netAccessKey"); goto fail; } peer_key = dpp_parse_jwk(peer_net_access_key, &curve); if (!peer_key) goto fail; dpp_debug_print_key("DPP: Received netAccessKey", peer_key); if (auth->curve != curve) { wpa_printf(MSG_DEBUG, "DPP: Mismatching netAccessKey curves (own=%s != peer=%s)", auth->curve->name, curve->name); goto fail; } auth->own_protocol_key = dpp_gen_keypair(curve); if (!auth->own_protocol_key) goto fail; if (random_get_bytes(auth->e_nonce, auth->curve->nonce_len)) { wpa_printf(MSG_ERROR, "DPP: Failed to generate E-nonce"); goto fail; } wpa_hexdump_key(MSG_DEBUG, "DPP: E-nonce", auth->e_nonce, auth->curve->nonce_len); /* M = { cR + pR } * CI */ cR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) own_key); pR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->own_protocol_key); if (!pR) goto fail; group = EC_KEY_get0_group(pR); bnctx = BN_CTX_new(); sum = BN_new(); mx = BN_new(); q = BN_new(); m = EC_POINT_new(group); if (!cR || !bnctx || !sum || !mx || !q || !m) goto fail; cR_bn = EC_KEY_get0_private_key(cR); pR_bn = EC_KEY_get0_private_key(pR); if (!cR_bn || !pR_bn) goto fail; CI = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) peer_key); CI_point = EC_KEY_get0_public_key(CI); if (EC_GROUP_get_order(group, q, bnctx) != 1 || BN_mod_add(sum, cR_bn, pR_bn, q, bnctx) != 1 || EC_POINT_mul(group, m, NULL, CI_point, sum, bnctx) != 1 || EC_POINT_get_affine_coordinates_GFp(group, m, mx, NULL, bnctx) != 1) { wpa_printf(MSG_ERROR, "OpenSSL: failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (dpp_bn2bin_pad(mx, Mx, curve->prime_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: M.x", Mx, curve->prime_len); /* ke = HKDF(C-nonce | E-nonce, "dpp reconfig key", M.x) */ /* HKDF-Extract(C-nonce | E-nonce, M.x) */ os_memcpy(nonces, auth->c_nonce, curve->nonce_len); os_memcpy(&nonces[curve->nonce_len], auth->e_nonce, curve->nonce_len); if (dpp_hmac(curve->hash_len, nonces, 2 * curve->nonce_len, Mx, curve->prime_len, prk) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK", prk, curve->hash_len); /* HKDF-Expand(PRK, "dpp reconfig key", L) */ if (dpp_hkdf_expand(curve->hash_len, prk, curve->hash_len, "dpp reconfig key", auth->ke, curve->hash_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ke = HKDF(C-nonce | E-nonce, \"dpp reconfig key\", M.x)", auth->ke, curve->hash_len); res = 0; crypto_ec_key_deinit(auth->reconfig_old_protocol_key); auth->reconfig_old_protocol_key = own_key; own_key = NULL; fail: forced_memzero(prk, sizeof(prk)); forced_memzero(Mx, sizeof(Mx)); EC_POINT_clear_free(m); BN_free(q); BN_clear_free(mx); BN_clear_free(sum); crypto_ec_key_deinit(own_key); crypto_ec_key_deinit(peer_key); BN_CTX_free(bnctx); return res; } int dpp_reconfig_derive_ke_initiator(struct dpp_authentication *auth, const u8 *r_proto, u16 r_proto_len, struct json_token *net_access_key) { BN_CTX *bnctx = NULL; struct crypto_ec_key *pr = NULL, *peer_key = NULL; EC_POINT *sum = NULL, *m = NULL; BIGNUM *mx = NULL; const EC_KEY *cI, *CR, *PR; const EC_GROUP *group; const EC_POINT *CR_point, *PR_point; const BIGNUM *cI_bn; u8 Mx[DPP_MAX_SHARED_SECRET_LEN]; u8 prk[DPP_MAX_HASH_LEN]; int res = -1; const struct dpp_curve_params *curve; u8 nonces[2 * DPP_MAX_NONCE_LEN]; pr = dpp_set_pubkey_point(auth->conf->connector_key, r_proto, r_proto_len); if (!pr) { dpp_auth_fail(auth, "Invalid Responder Protocol Key"); goto fail; } dpp_debug_print_key("Peer (Responder) Protocol Key", pr); crypto_ec_key_deinit(auth->peer_protocol_key); auth->peer_protocol_key = pr; pr = NULL; peer_key = dpp_parse_jwk(net_access_key, &curve); if (!peer_key) goto fail; dpp_debug_print_key("DPP: Received netAccessKey", peer_key); if (auth->curve != curve) { wpa_printf(MSG_DEBUG, "DPP: Mismatching netAccessKey curves (own=%s != peer=%s)", auth->curve->name, curve->name); goto fail; } /* M = cI * { CR + PR } */ cI = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->conf->connector_key); cI_bn = EC_KEY_get0_private_key(cI); group = EC_KEY_get0_group(cI); bnctx = BN_CTX_new(); sum = EC_POINT_new(group); m = EC_POINT_new(group); mx = BN_new(); CR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) peer_key); PR = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) auth->peer_protocol_key); CR_point = EC_KEY_get0_public_key(CR); PR_point = EC_KEY_get0_public_key(PR); if (!bnctx || !sum || !m || !mx || EC_POINT_add(group, sum, CR_point, PR_point, bnctx) != 1 || EC_POINT_mul(group, m, NULL, sum, cI_bn, bnctx) != 1 || EC_POINT_get_affine_coordinates_GFp(group, m, mx, NULL, bnctx) != 1 || dpp_bn2bin_pad(mx, Mx, curve->prime_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: M.x", Mx, curve->prime_len); /* ke = HKDF(C-nonce | E-nonce, "dpp reconfig key", M.x) */ /* HKDF-Extract(C-nonce | E-nonce, M.x) */ os_memcpy(nonces, auth->c_nonce, curve->nonce_len); os_memcpy(&nonces[curve->nonce_len], auth->e_nonce, curve->nonce_len); if (dpp_hmac(curve->hash_len, nonces, 2 * curve->nonce_len, Mx, curve->prime_len, prk) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: PRK", prk, curve->hash_len); /* HKDF-Expand(PRK, "dpp reconfig key", L) */ if (dpp_hkdf_expand(curve->hash_len, prk, curve->hash_len, "dpp reconfig key", auth->ke, curve->hash_len) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: ke = HKDF(C-nonce | E-nonce, \"dpp reconfig key\", M.x)", auth->ke, curve->hash_len); res = 0; fail: forced_memzero(prk, sizeof(prk)); forced_memzero(Mx, sizeof(Mx)); crypto_ec_key_deinit(pr); crypto_ec_key_deinit(peer_key); EC_POINT_clear_free(sum); EC_POINT_clear_free(m); BN_clear_free(mx); BN_CTX_free(bnctx); return res; } static char * dpp_build_jws_prot_hdr(struct dpp_configurator *conf, size_t *signed1_len) { struct wpabuf *jws_prot_hdr; char *signed1; jws_prot_hdr = wpabuf_alloc(100); if (!jws_prot_hdr) return NULL; json_start_object(jws_prot_hdr, NULL); json_add_string(jws_prot_hdr, "typ", "dppCon"); json_value_sep(jws_prot_hdr); json_add_string(jws_prot_hdr, "kid", conf->kid); json_value_sep(jws_prot_hdr); json_add_string(jws_prot_hdr, "alg", conf->curve->jws_alg); json_end_object(jws_prot_hdr); signed1 = base64_url_encode(wpabuf_head(jws_prot_hdr), wpabuf_len(jws_prot_hdr), signed1_len); wpabuf_free(jws_prot_hdr); return signed1; } static char * dpp_build_conn_signature(struct dpp_configurator *conf, const char *signed1, size_t signed1_len, const char *signed2, size_t signed2_len, size_t *signed3_len) { const struct dpp_curve_params *curve; char *signed3 = NULL; unsigned char *signature = NULL; const unsigned char *p; size_t signature_len; EVP_MD_CTX *md_ctx = NULL; ECDSA_SIG *sig = NULL; char *dot = "."; const EVP_MD *sign_md; const BIGNUM *r, *s; curve = conf->curve; if (curve->hash_len == SHA256_MAC_LEN) { sign_md = EVP_sha256(); } else if (curve->hash_len == SHA384_MAC_LEN) { sign_md = EVP_sha384(); } else if (curve->hash_len == SHA512_MAC_LEN) { sign_md = EVP_sha512(); } else { wpa_printf(MSG_DEBUG, "DPP: Unknown signature algorithm"); goto fail; } md_ctx = EVP_MD_CTX_create(); if (!md_ctx) goto fail; ERR_clear_error(); if (EVP_DigestSignInit(md_ctx, NULL, sign_md, NULL, (EVP_PKEY *) conf->csign) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignInit failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (EVP_DigestSignUpdate(md_ctx, signed1, signed1_len) != 1 || EVP_DigestSignUpdate(md_ctx, dot, 1) != 1 || EVP_DigestSignUpdate(md_ctx, signed2, signed2_len) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignUpdate failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } if (EVP_DigestSignFinal(md_ctx, NULL, &signature_len) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignFinal failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } signature = os_malloc(signature_len); if (!signature) goto fail; if (EVP_DigestSignFinal(md_ctx, signature, &signature_len) != 1) { wpa_printf(MSG_DEBUG, "DPP: EVP_DigestSignFinal failed: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } wpa_hexdump(MSG_DEBUG, "DPP: signedConnector ECDSA signature (DER)", signature, signature_len); /* Convert to raw coordinates r,s */ p = signature; sig = d2i_ECDSA_SIG(NULL, &p, signature_len); if (!sig) goto fail; ECDSA_SIG_get0(sig, &r, &s); if (dpp_bn2bin_pad(r, signature, curve->prime_len) < 0 || dpp_bn2bin_pad(s, signature + curve->prime_len, curve->prime_len) < 0) goto fail; signature_len = 2 * curve->prime_len; wpa_hexdump(MSG_DEBUG, "DPP: signedConnector ECDSA signature (raw r,s)", signature, signature_len); signed3 = base64_url_encode(signature, signature_len, signed3_len); fail: EVP_MD_CTX_destroy(md_ctx); ECDSA_SIG_free(sig); os_free(signature); return signed3; } char * dpp_sign_connector(struct dpp_configurator *conf, const struct wpabuf *dppcon) { char *signed1 = NULL, *signed2 = NULL, *signed3 = NULL; char *signed_conn = NULL, *pos; size_t signed1_len, signed2_len, signed3_len; signed1 = dpp_build_jws_prot_hdr(conf, &signed1_len); signed2 = base64_url_encode(wpabuf_head(dppcon), wpabuf_len(dppcon), &signed2_len); if (!signed1 || !signed2) goto fail; signed3 = dpp_build_conn_signature(conf, signed1, signed1_len, signed2, signed2_len, &signed3_len); if (!signed3) goto fail; signed_conn = os_malloc(signed1_len + signed2_len + signed3_len + 3); if (!signed_conn) goto fail; pos = signed_conn; os_memcpy(pos, signed1, signed1_len); pos += signed1_len; *pos++ = '.'; os_memcpy(pos, signed2, signed2_len); pos += signed2_len; *pos++ = '.'; os_memcpy(pos, signed3, signed3_len); pos += signed3_len; *pos = '\0'; fail: os_free(signed1); os_free(signed2); os_free(signed3); return signed_conn; } #ifdef CONFIG_DPP2 struct dpp_pfs * dpp_pfs_init(const u8 *net_access_key, size_t net_access_key_len) { struct wpabuf *pub = NULL; struct crypto_ec_key *own_key; struct dpp_pfs *pfs; pfs = os_zalloc(sizeof(*pfs)); if (!pfs) return NULL; own_key = dpp_set_keypair(&pfs->curve, net_access_key, net_access_key_len); if (!own_key) { wpa_printf(MSG_ERROR, "DPP: Failed to parse own netAccessKey"); goto fail; } crypto_ec_key_deinit(own_key); pfs->ecdh = crypto_ecdh_init(pfs->curve->ike_group); if (!pfs->ecdh) goto fail; pub = crypto_ecdh_get_pubkey(pfs->ecdh, 0); pub = wpabuf_zeropad(pub, pfs->curve->prime_len); if (!pub) goto fail; pfs->ie = wpabuf_alloc(5 + wpabuf_len(pub)); if (!pfs->ie) goto fail; wpabuf_put_u8(pfs->ie, WLAN_EID_EXTENSION); wpabuf_put_u8(pfs->ie, 1 + 2 + wpabuf_len(pub)); wpabuf_put_u8(pfs->ie, WLAN_EID_EXT_OWE_DH_PARAM); wpabuf_put_le16(pfs->ie, pfs->curve->ike_group); wpabuf_put_buf(pfs->ie, pub); wpabuf_free(pub); wpa_hexdump_buf(MSG_DEBUG, "DPP: Diffie-Hellman Parameter element", pfs->ie); return pfs; fail: wpabuf_free(pub); dpp_pfs_free(pfs); return NULL; } int dpp_pfs_process(struct dpp_pfs *pfs, const u8 *peer_ie, size_t peer_ie_len) { if (peer_ie_len < 2) return -1; if (WPA_GET_LE16(peer_ie) != pfs->curve->ike_group) { wpa_printf(MSG_DEBUG, "DPP: Peer used different group for PFS"); return -1; } pfs->secret = crypto_ecdh_set_peerkey(pfs->ecdh, 0, peer_ie + 2, peer_ie_len - 2); pfs->secret = wpabuf_zeropad(pfs->secret, pfs->curve->prime_len); if (!pfs->secret) { wpa_printf(MSG_DEBUG, "DPP: Invalid peer DH public key"); return -1; } wpa_hexdump_buf_key(MSG_DEBUG, "DPP: DH shared secret", pfs->secret); return 0; } void dpp_pfs_free(struct dpp_pfs *pfs) { if (!pfs) return; crypto_ecdh_deinit(pfs->ecdh); wpabuf_free(pfs->ie); wpabuf_clear_free(pfs->secret); os_free(pfs); } struct wpabuf * dpp_build_csr(struct dpp_authentication *auth, const char *name) { X509_REQ *req = NULL; struct wpabuf *buf = NULL; unsigned char *der; int der_len; struct crypto_ec_key *key; const EVP_MD *sign_md; unsigned int hash_len = auth->curve->hash_len; struct wpabuf *priv_key; BIO *out = NULL; u8 cp[DPP_CP_LEN]; char *password; size_t password_len; int res; /* TODO: use auth->csrattrs */ /* TODO: support generation of a new private key if csrAttrs requests * a specific group to be used */ key = auth->own_protocol_key; priv_key = crypto_ec_key_get_ecprivate_key(key, true); if (!priv_key) goto fail; wpabuf_free(auth->priv_key); auth->priv_key = priv_key; req = X509_REQ_new(); if (!req || !X509_REQ_set_pubkey(req, (EVP_PKEY *) key)) goto fail; if (name) { X509_NAME *n; n = X509_REQ_get_subject_name(req); if (!n) goto fail; if (X509_NAME_add_entry_by_txt( n, "CN", MBSTRING_UTF8, (const unsigned char *) name, -1, -1, 0) != 1) goto fail; } /* cp = HKDF-Expand(bk, "CSR challengePassword", 64) */ if (dpp_hkdf_expand(hash_len, auth->bk, hash_len, "CSR challengePassword", cp, DPP_CP_LEN) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: cp = HKDF-Expand(bk, \"CSR challengePassword\", 64)", cp, DPP_CP_LEN); password = base64_encode_no_lf(cp, DPP_CP_LEN, &password_len); forced_memzero(cp, DPP_CP_LEN); if (!password) goto fail; res = X509_REQ_add1_attr_by_NID(req, NID_pkcs9_challengePassword, V_ASN1_UTF8STRING, (const unsigned char *) password, password_len); bin_clear_free(password, password_len); if (!res) goto fail; /* TODO */ /* TODO: hash func selection based on csrAttrs */ if (hash_len == SHA256_MAC_LEN) { sign_md = EVP_sha256(); } else if (hash_len == SHA384_MAC_LEN) { sign_md = EVP_sha384(); } else if (hash_len == SHA512_MAC_LEN) { sign_md = EVP_sha512(); } else { wpa_printf(MSG_DEBUG, "DPP: Unknown signature algorithm"); goto fail; } if (!X509_REQ_sign(req, (EVP_PKEY *) key, sign_md)) goto fail; der = NULL; der_len = i2d_X509_REQ(req, &der); if (der_len < 0) goto fail; buf = wpabuf_alloc_copy(der, der_len); OPENSSL_free(der); wpa_hexdump_buf(MSG_DEBUG, "DPP: CSR", buf); fail: BIO_free_all(out); X509_REQ_free(req); return buf; } struct wpabuf * dpp_pkcs7_certs(const struct wpabuf *pkcs7) { #ifdef OPENSSL_IS_BORINGSSL CBS pkcs7_cbs; #else /* OPENSSL_IS_BORINGSSL */ PKCS7 *p7 = NULL; const unsigned char *p = wpabuf_head(pkcs7); #endif /* OPENSSL_IS_BORINGSSL */ STACK_OF(X509) *certs; int i, num; BIO *out = NULL; size_t rlen; struct wpabuf *pem = NULL; int res; #ifdef OPENSSL_IS_BORINGSSL certs = sk_X509_new_null(); if (!certs) goto fail; CBS_init(&pkcs7_cbs, wpabuf_head(pkcs7), wpabuf_len(pkcs7)); if (!PKCS7_get_certificates(certs, &pkcs7_cbs)) { wpa_printf(MSG_INFO, "DPP: Could not parse PKCS#7 object: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } #else /* OPENSSL_IS_BORINGSSL */ p7 = d2i_PKCS7(NULL, &p, wpabuf_len(pkcs7)); if (!p7) { wpa_printf(MSG_INFO, "DPP: Could not parse PKCS#7 object: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } switch (OBJ_obj2nid(p7->type)) { case NID_pkcs7_signed: certs = p7->d.sign->cert; break; case NID_pkcs7_signedAndEnveloped: certs = p7->d.signed_and_enveloped->cert; break; default: certs = NULL; break; } #endif /* OPENSSL_IS_BORINGSSL */ if (!certs || ((num = sk_X509_num(certs)) == 0)) { wpa_printf(MSG_INFO, "DPP: No certificates found in PKCS#7 object"); goto fail; } out = BIO_new(BIO_s_mem()); if (!out) goto fail; for (i = 0; i < num; i++) { X509 *cert = sk_X509_value(certs, i); PEM_write_bio_X509(out, cert); } rlen = BIO_ctrl_pending(out); pem = wpabuf_alloc(rlen); if (!pem) goto fail; res = BIO_read(out, wpabuf_put(pem, 0), rlen); if (res <= 0) { wpabuf_free(pem); pem = NULL; goto fail; } wpabuf_put(pem, res); fail: #ifdef OPENSSL_IS_BORINGSSL if (certs) sk_X509_pop_free(certs, X509_free); #else /* OPENSSL_IS_BORINGSSL */ PKCS7_free(p7); #endif /* OPENSSL_IS_BORINGSSL */ if (out) BIO_free_all(out); return pem; } int dpp_validate_csr(struct dpp_authentication *auth, const struct wpabuf *csr) { X509_REQ *req; const unsigned char *pos; EVP_PKEY *pkey; int res, loc, ret = -1; X509_ATTRIBUTE *attr; ASN1_TYPE *type; ASN1_STRING *str; unsigned char *utf8 = NULL; unsigned char *cp = NULL; size_t cp_len; u8 exp_cp[DPP_CP_LEN]; unsigned int hash_len = auth->curve->hash_len; pos = wpabuf_head(csr); req = d2i_X509_REQ(NULL, &pos, wpabuf_len(csr)); if (!req) { wpa_printf(MSG_DEBUG, "DPP: Failed to parse CSR"); return -1; } pkey = X509_REQ_get_pubkey(req); if (!pkey) { wpa_printf(MSG_DEBUG, "DPP: Failed to get public key from CSR"); goto fail; } res = X509_REQ_verify(req, pkey); EVP_PKEY_free(pkey); if (res != 1) { wpa_printf(MSG_DEBUG, "DPP: CSR does not have a valid signature"); goto fail; } loc = X509_REQ_get_attr_by_NID(req, NID_pkcs9_challengePassword, -1); if (loc < 0) { wpa_printf(MSG_DEBUG, "DPP: CSR does not include challengePassword"); goto fail; } attr = X509_REQ_get_attr(req, loc); if (!attr) { wpa_printf(MSG_DEBUG, "DPP: Could not get challengePassword attribute"); goto fail; } type = X509_ATTRIBUTE_get0_type(attr, 0); if (!type) { wpa_printf(MSG_DEBUG, "DPP: Could not get challengePassword attribute type"); goto fail; } res = ASN1_TYPE_get(type); /* This is supposed to be UTF8String, but allow other strings as well * since challengePassword is using ASCII (base64 encoded). */ if (res != V_ASN1_UTF8STRING && res != V_ASN1_PRINTABLESTRING && res != V_ASN1_IA5STRING) { wpa_printf(MSG_DEBUG, "DPP: Unexpected challengePassword attribute type %d", res); goto fail; } str = X509_ATTRIBUTE_get0_data(attr, 0, res, NULL); if (!str) { wpa_printf(MSG_DEBUG, "DPP: Could not get ASN.1 string for challengePassword"); goto fail; } res = ASN1_STRING_to_UTF8(&utf8, str); if (res < 0) { wpa_printf(MSG_DEBUG, "DPP: Could not get UTF8 version of challengePassword"); goto fail; } cp = base64_decode((const char *) utf8, res, &cp_len); OPENSSL_free(utf8); if (!cp) { wpa_printf(MSG_DEBUG, "DPP: Could not base64 decode challengePassword"); goto fail; } if (cp_len != DPP_CP_LEN) { wpa_printf(MSG_DEBUG, "DPP: Unexpected cp length (%zu) in CSR challengePassword", cp_len); goto fail; } wpa_hexdump_key(MSG_DEBUG, "DPP: cp from CSR challengePassword", cp, cp_len); /* cp = HKDF-Expand(bk, "CSR challengePassword", 64) */ if (dpp_hkdf_expand(hash_len, auth->bk, hash_len, "CSR challengePassword", exp_cp, DPP_CP_LEN) < 0) goto fail; wpa_hexdump_key(MSG_DEBUG, "DPP: cp = HKDF-Expand(bk, \"CSR challengePassword\", 64)", exp_cp, DPP_CP_LEN); if (os_memcmp_const(cp, exp_cp, DPP_CP_LEN) != 0) { wpa_printf(MSG_DEBUG, "DPP: CSR challengePassword does not match calculated cp"); goto fail; } ret = 0; fail: os_free(cp); X509_REQ_free(req); return ret; } struct dpp_reconfig_id * dpp_gen_reconfig_id(const u8 *csign_key, size_t csign_key_len, const u8 *pp_key, size_t pp_key_len) { const unsigned char *p; struct crypto_ec_key *csign = NULL, *ppkey = NULL; struct dpp_reconfig_id *id = NULL; BN_CTX *ctx = NULL; BIGNUM *bn = NULL, *q = NULL; const EC_KEY *eckey; const EC_GROUP *group; EC_POINT *e_id = NULL; p = csign_key; csign = (struct crypto_ec_key *) d2i_PUBKEY(NULL, &p, csign_key_len); if (!csign) goto fail; if (!pp_key) goto fail; p = pp_key; ppkey = (struct crypto_ec_key *) d2i_PUBKEY(NULL, &p, pp_key_len); if (!ppkey) goto fail; eckey = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) csign); if (!eckey) goto fail; group = EC_KEY_get0_group(eckey); if (!group) goto fail; e_id = EC_POINT_new(group); ctx = BN_CTX_new(); bn = BN_new(); q = BN_new(); if (!e_id || !ctx || !bn || !q || !EC_GROUP_get_order(group, q, ctx) || !BN_rand_range(bn, q) || !EC_POINT_mul(group, e_id, bn, NULL, NULL, ctx)) goto fail; dpp_debug_print_point("DPP: Generated random point E-id", group, e_id); id = os_zalloc(sizeof(*id)); if (!id) goto fail; id->group = group; id->e_id = e_id; e_id = NULL; id->csign = csign; csign = NULL; id->pp_key = ppkey; ppkey = NULL; fail: EC_POINT_free(e_id); crypto_ec_key_deinit(csign); crypto_ec_key_deinit(ppkey); BN_clear_free(bn); BN_CTX_free(ctx); return id; } static struct crypto_ec_key * dpp_pkey_from_point(const EC_GROUP *group, const EC_POINT *point) { EC_KEY *eckey; EVP_PKEY *pkey = NULL; eckey = EC_KEY_new(); if (!eckey || EC_KEY_set_group(eckey, group) != 1 || EC_KEY_set_public_key(eckey, point) != 1) { wpa_printf(MSG_ERROR, "DPP: Failed to set EC_KEY: %s", ERR_error_string(ERR_get_error(), NULL)); goto fail; } EC_KEY_set_asn1_flag(eckey, OPENSSL_EC_NAMED_CURVE); pkey = EVP_PKEY_new(); if (!pkey || EVP_PKEY_set1_EC_KEY(pkey, eckey) != 1) { wpa_printf(MSG_ERROR, "DPP: Could not create EVP_PKEY"); EVP_PKEY_free(pkey); pkey = NULL; goto fail; } fail: EC_KEY_free(eckey); return (struct crypto_ec_key *) pkey; } int dpp_update_reconfig_id(struct dpp_reconfig_id *id) { BN_CTX *ctx = NULL; BIGNUM *bn = NULL, *q = NULL; EC_POINT *e_prime_id = NULL, *a_nonce = NULL; int ret = -1; const EC_KEY *pp; const EC_POINT *pp_point; pp = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) id->pp_key); if (!pp) goto fail; pp_point = EC_KEY_get0_public_key(pp); e_prime_id = EC_POINT_new(id->group); a_nonce = EC_POINT_new(id->group); ctx = BN_CTX_new(); bn = BN_new(); q = BN_new(); /* Generate random 0 <= a-nonce < q * A-NONCE = a-nonce * G * E'-id = E-id + a-nonce * P_pk */ if (!pp_point || !e_prime_id || !a_nonce || !ctx || !bn || !q || !EC_GROUP_get_order(id->group, q, ctx) || !BN_rand_range(bn, q) || /* bn = a-nonce */ !EC_POINT_mul(id->group, a_nonce, bn, NULL, NULL, ctx) || !EC_POINT_mul(id->group, e_prime_id, NULL, pp_point, bn, ctx) || !EC_POINT_add(id->group, e_prime_id, id->e_id, e_prime_id, ctx)) goto fail; dpp_debug_print_point("DPP: Generated A-NONCE", id->group, a_nonce); dpp_debug_print_point("DPP: Encrypted E-id to E'-id", id->group, e_prime_id); crypto_ec_key_deinit(id->a_nonce); crypto_ec_key_deinit(id->e_prime_id); id->a_nonce = dpp_pkey_from_point(id->group, a_nonce); id->e_prime_id = dpp_pkey_from_point(id->group, e_prime_id); if (!id->a_nonce || !id->e_prime_id) goto fail; ret = 0; fail: EC_POINT_free(e_prime_id); EC_POINT_free(a_nonce); BN_clear_free(bn); BN_CTX_free(ctx); return ret; } void dpp_free_reconfig_id(struct dpp_reconfig_id *id) { if (id) { EC_POINT_clear_free(id->e_id); crypto_ec_key_deinit(id->csign); crypto_ec_key_deinit(id->a_nonce); crypto_ec_key_deinit(id->e_prime_id); crypto_ec_key_deinit(id->pp_key); os_free(id); } } EC_POINT * dpp_decrypt_e_id(struct crypto_ec_key *ppkey, struct crypto_ec_key *a_nonce, struct crypto_ec_key *e_prime_id) { const EC_KEY *pp_ec, *a_nonce_ec, *e_prime_id_ec; const BIGNUM *pp_bn; const EC_GROUP *group; EC_POINT *e_id = NULL; const EC_POINT *a_nonce_point, *e_prime_id_point; BN_CTX *ctx = NULL; if (!ppkey) return NULL; /* E-id = E'-id - s_C * A-NONCE */ pp_ec = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) ppkey); a_nonce_ec = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) a_nonce); e_prime_id_ec = EVP_PKEY_get0_EC_KEY((EVP_PKEY *) e_prime_id); if (!pp_ec || !a_nonce_ec || !e_prime_id_ec) return NULL; pp_bn = EC_KEY_get0_private_key(pp_ec); group = EC_KEY_get0_group(pp_ec); a_nonce_point = EC_KEY_get0_public_key(a_nonce_ec); e_prime_id_point = EC_KEY_get0_public_key(e_prime_id_ec); ctx = BN_CTX_new(); if (!pp_bn || !group || !a_nonce_point || !e_prime_id_point || !ctx) goto fail; e_id = EC_POINT_new(group); if (!e_id || !EC_POINT_mul(group, e_id, NULL, a_nonce_point, pp_bn, ctx) || !EC_POINT_invert(group, e_id, ctx) || !EC_POINT_add(group, e_id, e_prime_id_point, e_id, ctx)) { EC_POINT_clear_free(e_id); goto fail; } dpp_debug_print_point("DPP: Decrypted E-id", group, e_id); fail: BN_CTX_free(ctx); return e_id; } #endif /* CONFIG_DPP2 */ #ifdef CONFIG_TESTING_OPTIONS int dpp_test_gen_invalid_key(struct wpabuf *msg, const struct dpp_curve_params *curve) { BN_CTX *ctx; BIGNUM *x, *y; int ret = -1; EC_GROUP *group; EC_POINT *point; group = EC_GROUP_new_by_curve_name(OBJ_txt2nid(curve->name)); if (!group) return -1; ctx = BN_CTX_new(); point = EC_POINT_new(group); x = BN_new(); y = BN_new(); if (!ctx || !point || !x || !y) goto fail; if (BN_rand(x, curve->prime_len * 8, 0, 0) != 1) goto fail; /* Generate a random y coordinate that results in a point that is not * on the curve. */ for (;;) { if (BN_rand(y, curve->prime_len * 8, 0, 0) != 1) goto fail; if (EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx) != 1) { #if OPENSSL_VERSION_NUMBER >= 0x10100000L || defined(OPENSSL_IS_BORINGSSL) /* Unlike older OpenSSL versions, OpenSSL 1.1.1 and BoringSSL * return an error from EC_POINT_set_affine_coordinates_GFp() * when the point is not on the curve. */ break; #else /* >=1.1.0 or OPENSSL_IS_BORINGSSL */ goto fail; #endif /* >= 1.1.0 or OPENSSL_IS_BORINGSSL */ } if (!EC_POINT_is_on_curve(group, point, ctx)) break; } if (dpp_bn2bin_pad(x, wpabuf_put(msg, curve->prime_len), curve->prime_len) < 0 || dpp_bn2bin_pad(y, wpabuf_put(msg, curve->prime_len), curve->prime_len) < 0) goto fail; ret = 0; fail: if (ret < 0) wpa_printf(MSG_INFO, "DPP: Failed to generate invalid key"); BN_free(x); BN_free(y); EC_POINT_free(point); BN_CTX_free(ctx); EC_GROUP_free(group); return ret; } char * dpp_corrupt_connector_signature(const char *connector) { char *tmp, *pos, *signed3 = NULL; unsigned char *signature = NULL; size_t signature_len = 0, signed3_len; tmp = os_zalloc(os_strlen(connector) + 5); if (!tmp) goto fail; os_memcpy(tmp, connector, os_strlen(connector)); pos = os_strchr(tmp, '.'); if (!pos) goto fail; pos = os_strchr(pos + 1, '.'); if (!pos) goto fail; pos++; wpa_printf(MSG_DEBUG, "DPP: Original base64url encoded signature: %s", pos); signature = base64_url_decode(pos, os_strlen(pos), &signature_len); if (!signature || signature_len == 0) goto fail; wpa_hexdump(MSG_DEBUG, "DPP: Original Connector signature", signature, signature_len); signature[signature_len - 1] ^= 0x01; wpa_hexdump(MSG_DEBUG, "DPP: Corrupted Connector signature", signature, signature_len); signed3 = base64_url_encode(signature, signature_len, &signed3_len); if (!signed3) goto fail; os_memcpy(pos, signed3, signed3_len); pos[signed3_len] = '\0'; wpa_printf(MSG_DEBUG, "DPP: Corrupted base64url encoded signature: %s", pos); out: os_free(signature); os_free(signed3); return tmp; fail: os_free(tmp); tmp = NULL; goto out; } #endif /* CONFIG_TESTING_OPTIONS */