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hostapd/src/common/dpp_crypto.c
Cedric Izoard 0d1d74107b DPP: Update PKEX part to use crypto.h API 
Rewrite EC point/bignum computation done in PKEX protocol using EC
point/bignum primitives already defined in crypto.h and couple of small
new helper functions.

Signed-off-by: Cedric Izoard <cedric.izoard@ceva-dsp.com>
2021-10-26 23:20:57 +03:00

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/*
* 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 <openssl/opensslv.h>
#include <openssl/err.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/pem.h>
#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;
}
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 crypto_ec_key * dpp_set_pubkey_point(struct crypto_ec_key *group_key,
const u8 *buf, size_t len)
{
int ike_group = crypto_ec_key_group(group_key);
if (len & 1)
return NULL;
if (ike_group < 0) {
wpa_printf(MSG_ERROR, "DPP: Could not get EC group");
return NULL;
}
return crypto_ec_key_set_pub(ike_group, buf, buf + len / 2, len / 2);
}
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)
{
struct crypto_ec_key *key;
int group;
key = crypto_ec_key_parse_priv(privkey, privkey_len);
if (!key) {
wpa_printf(MSG_INFO, "DPP: Failed to parse private key");
return NULL;
}
group = crypto_ec_key_group(key);
if (group < 0) {
crypto_ec_key_deinit(key);
return NULL;
}
*curve = dpp_get_curve_ike_group(group);
if (!*curve) {
wpa_printf(MSG_INFO,
"DPP: Unsupported curve (group=%d) in pre-assigned key",
group);
crypto_ec_key_deinit(key);
return NULL;
}
return key;
}
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)
{
struct crypto_ec_key *key;
if (dpp_bi_pubkey_hash(bi, data, data_len) < 0) {
wpa_printf(MSG_DEBUG, "DPP: Failed to hash public key");
return -1;
}
key = crypto_ec_key_parse_pub(data, data_len);
if (!key) {
wpa_printf(MSG_DEBUG,
"DPP: Could not parse URI public-key SubjectPublicKeyInfo");
return -1;
}
bi->curve = dpp_get_curve_ike_group(crypto_ec_key_group(key));
if (!bi->curve) {
wpa_printf(MSG_DEBUG,
"DPP: Unsupported SubjectPublicKeyInfo curve: group %d",
crypto_ec_key_group(key));
goto fail;
}
bi->pubkey = key;
return 0;
fail:
crypto_ec_key_deinit(key);
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 = crypto_ec_key_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)
{
struct crypto_ec_key *csign;
char *signed_connector = NULL;
enum dpp_status_error res = DPP_STATUS_INVALID_CONNECTOR;
csign = crypto_ec_key_parse_pub(csign_key, 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 = crypto_ec_key_get_pubkey_point(auth->own_protocol_key, 0);
prx = crypto_ec_key_get_pubkey_point(auth->peer_protocol_key,
0);
if (auth->own_bi)
bix = crypto_ec_key_get_pubkey_point(
auth->own_bi->pubkey, 0);
else
bix = NULL;
brx = crypto_ec_key_get_pubkey_point(auth->peer_bi->pubkey, 0);
} else {
pix = crypto_ec_key_get_pubkey_point(auth->peer_protocol_key,
0);
prx = crypto_ec_key_get_pubkey_point(auth->own_protocol_key, 0);
if (auth->peer_bi)
bix = crypto_ec_key_get_pubkey_point(
auth->peer_bi->pubkey, 0);
else
bix = NULL;
brx = crypto_ec_key_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 = crypto_ec_key_get_pubkey_point(auth->own_protocol_key, 0);
prx = crypto_ec_key_get_pubkey_point(auth->peer_protocol_key,
0);
if (auth->own_bi)
bix = crypto_ec_key_get_pubkey_point(
auth->own_bi->pubkey, 0);
else
bix = NULL;
if (!auth->peer_bi)
goto fail;
brx = crypto_ec_key_get_pubkey_point(auth->peer_bi->pubkey, 0);
} else {
pix = crypto_ec_key_get_pubkey_point(auth->peer_protocol_key,
0);
prx = crypto_ec_key_get_pubkey_point(auth->own_protocol_key, 0);
if (auth->peer_bi)
bix = crypto_ec_key_get_pubkey_point(
auth->peer_bi->pubkey, 0);
else
bix = NULL;
if (!auth->own_bi)
goto fail;
brx = crypto_ec_key_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 = crypto_ec_key_get_pubkey_point(own_key, 0);
pkx = crypto_ec_key_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)
{
const u8 *x, *y;
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;
}
return crypto_ec_key_set_pub(curve->ike_group, x, y, curve->prime_len);
}
struct crypto_ec_point *
dpp_pkex_derive_Qi(const struct dpp_curve_params *curve, const u8 *mac_init,
const char *code, const char *identifier,
struct crypto_ec **ret_ec)
{
u8 hash[DPP_MAX_HASH_LEN];
const u8 *addr[3];
size_t len[3];
unsigned int num_elem = 0;
struct crypto_ec_point *Qi = NULL;
struct crypto_ec_key *Pi_key = NULL;
const struct crypto_ec_point *Pi = NULL;
struct crypto_bignum *hash_bn = NULL;
struct crypto_ec *ec = 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_key = dpp_pkex_get_role_elem(curve, 1);
if (!Pi_key)
goto fail;
dpp_debug_print_key("DPP: Pi", Pi_key);
ec = crypto_ec_init(curve->ike_group);
if (!ec)
goto fail;
Pi = crypto_ec_key_get_public_key(Pi_key);
Qi = crypto_ec_point_init(ec);
hash_bn = crypto_bignum_init_set(hash, curve->hash_len);
if (!Pi || !Qi || !hash_bn || crypto_ec_point_mul(ec, Pi, hash_bn, Qi))
goto fail;
if (crypto_ec_point_is_at_infinity(ec, Qi)) {
wpa_printf(MSG_INFO, "DPP: Qi is the point-at-infinity");
goto fail;
}
crypto_ec_point_debug_print(ec, Qi, "DPP: Qi");
out:
crypto_ec_key_deinit(Pi_key);
crypto_bignum_deinit(hash_bn, 1);
if (ret_ec && Qi)
*ret_ec = ec;
else
crypto_ec_deinit(ec);
return Qi;
fail:
crypto_ec_point_deinit(Qi, 1);
Qi = NULL;
goto out;
}
struct crypto_ec_point *
dpp_pkex_derive_Qr(const struct dpp_curve_params *curve, const u8 *mac_resp,
const char *code, const char *identifier,
struct crypto_ec **ret_ec)
{
u8 hash[DPP_MAX_HASH_LEN];
const u8 *addr[3];
size_t len[3];
unsigned int num_elem = 0;
struct crypto_ec_point *Qr = NULL;
struct crypto_ec_key *Pr_key = NULL;
const struct crypto_ec_point *Pr = NULL;
struct crypto_bignum *hash_bn = NULL;
struct crypto_ec *ec = 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_key = dpp_pkex_get_role_elem(curve, 0);
if (!Pr_key)
goto fail;
dpp_debug_print_key("DPP: Pr", Pr_key);
ec = crypto_ec_init(curve->ike_group);
if (!ec)
goto fail;
Pr = crypto_ec_key_get_public_key(Pr_key);
Qr = crypto_ec_point_init(ec);
hash_bn = crypto_bignum_init_set(hash, curve->hash_len);
if (!Pr || !Qr || !hash_bn || crypto_ec_point_mul(ec, Pr, hash_bn, Qr))
goto fail;
if (crypto_ec_point_is_at_infinity(ec, Qr)) {
wpa_printf(MSG_INFO, "DPP: Qr is the point-at-infinity");
goto fail;
}
crypto_ec_point_debug_print(ec, Qr, "DPP: Qr");
out:
crypto_ec_key_deinit(Pr_key);
crypto_bignum_deinit(hash_bn, 1);
if (ret_ec && Qr)
*ret_ec = ec;
else
crypto_ec_deinit(ec);
return Qr;
fail:
crypto_ec_point_deinit(Qr, 1);
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 */
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