wpabuf_free(tmp->own_rejected_groups);
wpabuf_free(tmp->peer_rejected_groups);
os_free(tmp->pw_id);
+#ifdef CONFIG_SAE_PK
+ bin_clear_free(tmp->pw, tmp->pw_len);
+#endif /* CONFIG_SAE_PK */
bin_clear_free(tmp, sizeof(*tmp));
sae->tmp = NULL;
}
wpa_printf(MSG_DEBUG, "SAE: Derive PT - group %d", group);
+ if (ssid_len > 32)
+ return NULL;
+
pt = os_zalloc(sizeof(*pt));
if (!pt)
return NULL;
+#ifdef CONFIG_SAE_PK
+ os_memcpy(pt->ssid, ssid, ssid_len);
+ pt->ssid_len = ssid_len;
+#endif /* CONFIG_SAE_PK */
pt->group = group;
pt->ec = crypto_ec_init(group);
if (pt->ec) {
return -1;
sae->tmp->h2e = 0;
+ sae->tmp->pk = 0;
return sae_derive_commit(sae);
}
int sae_prepare_commit_pt(struct sae_data *sae, const struct sae_pt *pt,
const u8 *addr1, const u8 *addr2,
- int *rejected_groups)
+ int *rejected_groups, const struct sae_pk *pk)
{
if (!sae->tmp)
return -1;
return -1;
}
+#ifdef CONFIG_SAE_PK
+ os_memcpy(sae->tmp->ssid, pt->ssid, pt->ssid_len);
+ sae->tmp->ssid_len = pt->ssid_len;
+ sae->tmp->ap_pk = pk;
+ /* TODO: Could support alternative groups as long as the combination
+ * meets the requirements. */
+ if (pk && pk->group != sae->group) {
+ wpa_printf(MSG_DEBUG,
+ "SAE-PK: Reject attempt to use group %d since K_AP use group %d",
+ sae->group, pk->group);
+ sae->tmp->reject_group = true;
+ return -1;
+ }
+#endif /* CONFIG_SAE_PK */
sae->tmp->own_addr_higher = os_memcmp(addr1, addr2, ETH_ALEN) > 0;
wpabuf_free(sae->tmp->own_rejected_groups);
sae->tmp->own_rejected_groups = NULL;
const u8 *salt;
struct wpabuf *rejected_groups = NULL;
u8 keyseed[SAE_MAX_HASH_LEN];
- u8 keys[SAE_MAX_HASH_LEN + SAE_PMK_LEN];
+ u8 keys[2 * SAE_MAX_HASH_LEN + SAE_PMK_LEN];
struct crypto_bignum *tmp;
int ret = -1;
size_t hash_len, salt_len, prime_len = sae->tmp->prime_len;
* KCK || PMK = KDF-Hash-Length(keyseed, "SAE KCK and PMK",
* (commit-scalar + peer-commit-scalar) modulo r)
* PMKID = L((commit-scalar + peer-commit-scalar) modulo r, 0, 128)
+ *
+ * When SAE-PK is used,
+ * KCK || PMK || KEK = KDF-Hash-Length(keyseed, "SAE-PK keys", context)
*/
if (!sae->tmp->h2e)
hash_len = SHA256_MAC_LEN;
* octets). */
crypto_bignum_to_bin(tmp, val, sizeof(val), sae->tmp->order_len);
wpa_hexdump(MSG_DEBUG, "SAE: PMKID", val, SAE_PMKID_LEN);
- if (sae_kdf_hash(hash_len, keyseed, "SAE KCK and PMK",
+ if (!sae->tmp->pk &&
+ sae_kdf_hash(hash_len, keyseed, "SAE KCK and PMK",
val, sae->tmp->order_len,
keys, hash_len + SAE_PMK_LEN) < 0)
goto fail;
+#ifdef CONFIG_SAE_PK
+ if (sae->tmp->pk &&
+ sae_kdf_hash(hash_len, keyseed, "SAE-PK keys",
+ val, sae->tmp->order_len,
+ keys, 2 * hash_len + SAE_PMK_LEN) < 0)
+ goto fail;
+#endif /* CONFIG_SAE_PK */
forced_memzero(keyseed, sizeof(keyseed));
os_memcpy(sae->tmp->kck, keys, hash_len);
sae->tmp->kck_len = hash_len;
os_memcpy(sae->pmk, keys + hash_len, SAE_PMK_LEN);
os_memcpy(sae->pmkid, val, SAE_PMKID_LEN);
+#ifdef CONFIG_SAE_PK
+ if (sae->tmp->pk) {
+ os_memcpy(sae->tmp->kek, keys + hash_len + SAE_PMK_LEN,
+ hash_len);
+ sae->tmp->kek_len = hash_len;
+ wpa_hexdump_key(MSG_DEBUG, "SAE: KEK for SAE-PK",
+ sae->tmp->kek, sae->tmp->kek_len);
+ }
+#endif /* CONFIG_SAE_PK */
forced_memzero(keys, sizeof(keys));
wpa_hexdump_key(MSG_DEBUG, "SAE: KCK",
sae->tmp->kck, sae->tmp->kck_len);
}
-void sae_write_confirm(struct sae_data *sae, struct wpabuf *buf)
+int sae_write_confirm(struct sae_data *sae, struct wpabuf *buf)
{
const u8 *sc;
size_t hash_len;
+ int res;
if (sae->tmp == NULL)
- return;
+ return -1;
hash_len = sae->tmp->kck_len;
sae->send_confirm++;
if (sae->tmp->ec)
- sae_cn_confirm_ecc(sae, sc, sae->tmp->own_commit_scalar,
- sae->tmp->own_commit_element_ecc,
- sae->peer_commit_scalar,
- sae->tmp->peer_commit_element_ecc,
- wpabuf_put(buf, hash_len));
+ res = sae_cn_confirm_ecc(sae, sc, sae->tmp->own_commit_scalar,
+ sae->tmp->own_commit_element_ecc,
+ sae->peer_commit_scalar,
+ sae->tmp->peer_commit_element_ecc,
+ wpabuf_put(buf, hash_len));
else
- sae_cn_confirm_ffc(sae, sc, sae->tmp->own_commit_scalar,
- sae->tmp->own_commit_element_ffc,
- sae->peer_commit_scalar,
- sae->tmp->peer_commit_element_ffc,
- wpabuf_put(buf, hash_len));
+ res = sae_cn_confirm_ffc(sae, sc, sae->tmp->own_commit_scalar,
+ sae->tmp->own_commit_element_ffc,
+ sae->peer_commit_scalar,
+ sae->tmp->peer_commit_element_ffc,
+ wpabuf_put(buf, hash_len));
+ if (res)
+ return res;
+
+#ifdef CONFIG_SAE_PK
+ if (sae_write_confirm_pk(sae, buf) < 0)
+ return -1;
+#endif /* CONFIG_SAE_PK */
+
+ return 0;
}
return -1;
}
+#ifdef CONFIG_SAE_PK
+ if (sae_check_confirm_pk(sae, data + 2 + hash_len,
+ len - 2 - hash_len) < 0)
+ return -1;
+#endif /* CONFIG_SAE_PK */
+
return 0;
}
--- /dev/null
+/*
+ * SAE-PK
+ * Copyright (c) 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 <stdint.h>
+
+#include "utils/common.h"
+#include "utils/base64.h"
+#include "common/ieee802_11_defs.h"
+#include "common/ieee802_11_common.h"
+#include "crypto/crypto.h"
+#include "crypto/aes.h"
+#include "crypto/aes_siv.h"
+#include "sae.h"
+
+
+/* RFC 4648 base 32 alphabet with lowercase characters */
+static const char *sae_pk_base32_table = "abcdefghijklmnopqrstuvwxyz234567";
+
+
+bool sae_pk_valid_password(const char *pw)
+{
+ int pos;
+
+ /* Minimum password length for SAE-PK is not defined, but the automatic
+ * password style determination is more reliable if at least one hyphen
+ * is forced to be present in the password. */
+ if (os_strlen(pw) < 6)
+ return false;
+
+ for (pos = 0; pw[pos]; pos++) {
+ if (pos && pos % 5 == 4) {
+ if (pw[pos] != '-')
+ return false;
+ continue;
+ }
+ if (!os_strchr(sae_pk_base32_table, pw[pos]))
+ return false;
+ }
+ if (pos == 0)
+ return false;
+ return pw[pos - 1] != '-';
+}
+
+
+static char * add_char(const char *start, char *pos, u8 idx, size_t *bits)
+{
+ if (*bits == 0)
+ return pos;
+ if (*bits > 5)
+ *bits -= 5;
+ else
+ *bits = 0;
+
+ if ((pos - start) % 5 == 4)
+ *pos++ = '-';
+ *pos++ = sae_pk_base32_table[idx];
+ return pos;
+}
+
+
+char * sae_pk_base32_encode(const u8 *src, size_t len_bits)
+{
+ char *out, *pos;
+ size_t olen, extra_pad, i;
+ u64 block = 0;
+ u8 val;
+ size_t len = (len_bits + 7) / 8;
+ size_t left = len_bits;
+ int j;
+
+ if (len == 0 || len >= SIZE_MAX / 8)
+ return NULL;
+ olen = len * 8 / 5 + 1;
+ olen += olen / 4; /* hyphen separators */
+ pos = out = os_zalloc(olen + 1);
+ if (!out)
+ return NULL;
+
+ extra_pad = (5 - len % 5) % 5;
+ for (i = 0; i < len + extra_pad; i++) {
+ val = i < len ? src[i] : 0;
+ block <<= 8;
+ block |= val;
+ if (i % 5 == 4) {
+ for (j = 7; j >= 0; j--)
+ pos = add_char(out, pos,
+ (block >> j * 5) & 0x1f, &left);
+ block = 0;
+ }
+ }
+
+ return out;
+}
+
+
+u8 * sae_pk_base32_decode(const char *src, size_t len, size_t *out_len)
+{
+ u8 dtable[256], *out, *pos, tmp;
+ u64 block = 0;
+ size_t i, count, olen;
+ int pad = 0;
+ size_t extra_pad;
+
+ os_memset(dtable, 0x80, 256);
+ for (i = 0; sae_pk_base32_table[i]; i++)
+ dtable[(u8) sae_pk_base32_table[i]] = i;
+ dtable['='] = 0;
+
+ count = 0;
+ for (i = 0; i < len; i++) {
+ if (dtable[(u8) src[i]] != 0x80)
+ count++;
+ }
+
+ if (count == 0)
+ return NULL;
+ extra_pad = (8 - count % 8) % 8;
+
+ olen = (count + extra_pad) / 8 * 5;
+ pos = out = os_malloc(olen);
+ if (!out)
+ return NULL;
+
+ count = 0;
+ for (i = 0; i < len + extra_pad; i++) {
+ u8 val;
+
+ if (i >= len)
+ val = '=';
+ else
+ val = src[i];
+ tmp = dtable[val];
+ if (tmp == 0x80)
+ continue;
+
+ if (val == '=')
+ pad++;
+ block <<= 5;
+ block |= tmp;
+ count++;
+ if (count == 8) {
+ *pos++ = (block >> 32) & 0xff;
+ *pos++ = (block >> 24) & 0xff;
+ *pos++ = (block >> 16) & 0xff;
+ *pos++ = (block >> 8) & 0xff;
+ *pos++ = block & 0xff;
+ count = 0;
+ block = 0;
+ if (pad) {
+ /* Leave in all the available bits with zero
+ * padding to full octets from right. */
+ pos -= pad * 5 / 8;
+ break;
+ }
+ }
+ }
+
+ *out_len = pos - out;
+ return out;
+}
+
+
+int sae_pk_set_password(struct sae_data *sae, const char *password)
+{
+ struct sae_temporary_data *tmp = sae->tmp;
+ size_t len;
+
+ len = os_strlen(password);
+ if (!tmp || len < 1)
+ return -1;
+
+ bin_clear_free(tmp->pw, tmp->pw_len);
+ tmp->pw = sae_pk_base32_decode(password, len, &tmp->pw_len);
+ tmp->lambda = len - len / 5;
+ return tmp->pw ? 0 : -1;
+}
+
+
+void sae_deinit_pk(struct sae_pk *pk)
+{
+ if (pk) {
+ wpabuf_free(pk->m);
+ crypto_ec_key_deinit(pk->key);
+ wpabuf_free(pk->pubkey);
+ os_free(pk);
+ }
+}
+
+
+struct sae_pk * sae_parse_pk(const char *val)
+{
+ struct sae_pk *pk;
+ const char *pos;
+ size_t len;
+ unsigned char *der;
+ size_t der_len;
+
+ /* <m-as-hexdump>:<base64-encoded-DER-encoded-key> */
+
+ pos = os_strchr(val, ':');
+ if (!pos || (pos - val) & 0x01)
+ return NULL;
+ len = (pos - val) / 2;
+ if (len != SAE_PK_M_LEN) {
+ wpa_printf(MSG_INFO, "SAE: Unexpected Modifier M length %zu",
+ len);
+ return NULL;
+ }
+
+ pk = os_zalloc(sizeof(*pk));
+ if (!pk)
+ return NULL;
+ pk->m = wpabuf_alloc(len);
+ if (!pk->m || hexstr2bin(val, wpabuf_put(pk->m, len), len)) {
+ wpa_printf(MSG_INFO, "SAE: Failed to parse m");
+ goto fail;
+ }
+
+ pos++;
+ der = base64_decode(pos, os_strlen(pos), &der_len);
+ if (!der) {
+ wpa_printf(MSG_INFO, "SAE: Failed to base64 decode PK key");
+ goto fail;
+ }
+
+ pk->key = crypto_ec_key_parse_priv(der, der_len);
+ bin_clear_free(der, der_len);
+ if (!pk->key)
+ goto fail;
+ pk->group = crypto_ec_key_group(pk->key);
+ pk->pubkey = crypto_ec_key_get_subject_public_key(pk->key);
+ if (!pk->pubkey)
+ goto fail;
+
+ return pk;
+fail:
+ sae_deinit_pk(pk);
+ return NULL;
+}
+
+
+int sae_hash(size_t hash_len, const u8 *data, size_t len, u8 *hash)
+{
+ if (hash_len == 32)
+ return sha256_vector(1, &data, &len, hash);
+#ifdef CONFIG_SHA384
+ if (hash_len == 48)
+ return sha384_vector(1, &data, &len, hash);
+#endif /* CONFIG_SHA384 */
+#ifdef CONFIG_SHA512
+ if (hash_len == 64)
+ return sha512_vector(1, &data, &len, hash);
+#endif /* CONFIG_SHA512 */
+ return -1;
+}
+
+
+static int sae_pk_hash_sig_data(struct sae_data *sae, size_t hash_len,
+ bool ap, const u8 *m, size_t m_len,
+ const u8 *pubkey, size_t pubkey_len, u8 *hash)
+{
+ struct sae_temporary_data *tmp = sae->tmp;
+ struct wpabuf *sig_data;
+ u8 *pos;
+ int ret = -1;
+
+ /* Signed data for KeyAuth: eleAP || eleSTA || scaAP || scaSTA ||
+ * M || K_AP || AP-BSSID || STA-MAC */
+ sig_data = wpabuf_alloc(tmp->prime_len * 6 + m_len + pubkey_len +
+ 2 * ETH_ALEN);
+ if (!sig_data)
+ goto fail;
+ pos = wpabuf_put(sig_data, 2 * tmp->prime_len);
+ if (crypto_ec_point_to_bin(tmp->ec, ap ? tmp->own_commit_element_ecc :
+ tmp->peer_commit_element_ecc,
+ pos, pos + tmp->prime_len) < 0)
+ goto fail;
+ pos = wpabuf_put(sig_data, 2 * tmp->prime_len);
+ if (crypto_ec_point_to_bin(tmp->ec, ap ? tmp->peer_commit_element_ecc :
+ tmp->own_commit_element_ecc,
+ pos, pos + tmp->prime_len) < 0)
+ goto fail;
+ if (crypto_bignum_to_bin(ap ? tmp->own_commit_scalar :
+ sae->peer_commit_scalar,
+ wpabuf_put(sig_data, tmp->prime_len),
+ tmp->prime_len, tmp->prime_len) < 0 ||
+ crypto_bignum_to_bin(ap ? sae->peer_commit_scalar :
+ tmp->own_commit_scalar,
+ wpabuf_put(sig_data, tmp->prime_len),
+ tmp->prime_len, tmp->prime_len) < 0)
+ goto fail;
+ wpabuf_put_data(sig_data, m, m_len);
+ wpabuf_put_data(sig_data, pubkey, pubkey_len);
+ wpabuf_put_data(sig_data, ap ? tmp->own_addr : tmp->peer_addr,
+ ETH_ALEN);
+ wpabuf_put_data(sig_data, ap ? tmp->peer_addr : tmp->own_addr,
+ ETH_ALEN);
+ wpa_hexdump_buf_key(MSG_DEBUG, "SAE-PK: Data to be signed for KeyAuth",
+ sig_data);
+ if (sae_hash(hash_len, wpabuf_head(sig_data), wpabuf_len(sig_data),
+ hash) < 0)
+ goto fail;
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: hash(data to be signed)",
+ hash, hash_len);
+ ret = 0;
+fail:
+ wpabuf_free(sig_data);
+ return ret;
+}
+
+
+int sae_write_confirm_pk(struct sae_data *sae, struct wpabuf *buf)
+{
+ struct sae_temporary_data *tmp = sae->tmp;
+ struct wpabuf *elem = NULL, *sig = NULL;
+ size_t extra;
+ int ret = -1;
+ u8 *encr_mod;
+ size_t encr_mod_len;
+ const struct sae_pk *pk;
+ u8 hash[SAE_MAX_HASH_LEN];
+ size_t hash_len;
+
+ if (!tmp)
+ return -1;
+
+ pk = tmp->ap_pk;
+ if (!pk)
+ return 0;
+
+ if (tmp->kek_len != 32 && tmp->kek_len != 48 && tmp->kek_len != 64) {
+ wpa_printf(MSG_INFO, "SAE-PK: No KEK available for confirm");
+ return -1;
+ }
+
+ if (!tmp->ec) {
+ /* Only ECC groups are supported for SAE-PK in the current
+ * implementation. */
+ wpa_printf(MSG_INFO,
+ "SAE-PK: SAE commit did not use an ECC group");
+ return -1;
+ }
+
+ hash_len = sae_ecc_prime_len_2_hash_len(tmp->prime_len);
+ if (sae_pk_hash_sig_data(sae, hash_len, true, wpabuf_head(pk->m),
+ wpabuf_len(pk->m), wpabuf_head(pk->pubkey),
+ wpabuf_len(pk->pubkey), hash) < 0)
+ goto fail;
+ sig = crypto_ec_key_sign(pk->key, hash, hash_len);
+ if (!sig)
+ goto fail;
+ wpa_hexdump_buf(MSG_DEBUG, "SAE-PK: KeyAuth = Sig_AP()", sig);
+
+ elem = wpabuf_alloc(1500 + wpabuf_len(sig));
+ if (!elem)
+ goto fail;
+
+ /* EncryptedModifier = AES-SIV-Q(M); no AAD */
+ encr_mod_len = wpabuf_len(pk->m) + AES_BLOCK_SIZE;
+ wpabuf_put_u8(elem, encr_mod_len);
+ encr_mod = wpabuf_put(elem, encr_mod_len);
+ if (aes_siv_encrypt(tmp->kek, tmp->kek_len,
+ wpabuf_head(pk->m), wpabuf_len(pk->m),
+ 0, NULL, NULL, encr_mod) < 0)
+ goto fail;
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: EncryptedModifier",
+ encr_mod, encr_mod_len);
+
+ /* FILS Public Key element */
+ wpabuf_put_u8(elem, WLAN_EID_EXTENSION);
+ wpabuf_put_u8(elem, 2 + wpabuf_len(pk->pubkey));
+ wpabuf_put_u8(elem, WLAN_EID_EXT_FILS_PUBLIC_KEY);
+ wpabuf_put_u8(elem, 3); /* Key Type: ECDSA public key */
+ wpabuf_put_buf(elem, pk->pubkey);
+
+ /* FILS Key Confirmation element (KeyAuth) */
+ wpabuf_put_u8(elem, WLAN_EID_EXTENSION);
+ wpabuf_put_u8(elem, 1 + wpabuf_len(sig));
+ wpabuf_put_u8(elem, WLAN_EID_EXT_FILS_KEY_CONFIRM);
+ /* KeyAuth = Sig_AP(eleAP || eleSTA || scaAP || scaSTA || M || K_AP ||
+ * AP-BSSID || STA-MAC) */
+ wpabuf_put_buf(elem, sig);
+
+ /* TODO: fragmentation */
+ extra = 6; /* Vendor specific element header */
+
+ if (wpabuf_tailroom(elem) < extra + wpabuf_len(buf)) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: No room in message buffer for SAE-PK element (%zu < %zu)",
+ wpabuf_tailroom(buf), extra + wpabuf_len(buf));
+ goto fail;
+ }
+
+ /* SAE-PK element */
+ wpabuf_put_u8(buf, WLAN_EID_VENDOR_SPECIFIC);
+ wpabuf_put_u8(buf, 4 + wpabuf_len(elem));
+ wpabuf_put_be32(buf, SAE_PK_IE_VENDOR_TYPE);
+ wpabuf_put_buf(buf, elem);
+
+ ret = 0;
+fail:
+ wpabuf_free(elem);
+ wpabuf_free(sig);
+ return ret;
+
+}
+
+
+static bool sae_pk_valid_fingerprint(struct sae_data *sae,
+ const u8 *m, size_t m_len,
+ const u8 *k_ap, size_t k_ap_len)
+{
+ struct sae_temporary_data *tmp = sae->tmp;
+ size_t sec, i;
+ u8 *fingerprint_exp, *hash_data, *pos;
+ size_t hash_len, hash_data_len, fingerprint_bits, fingerprint_bytes;
+ u8 hash[SAE_MAX_HASH_LEN];
+ int res;
+
+ if (!tmp->pw || tmp->pw_len < 1) {
+ wpa_printf(MSG_DEBUG,
+ "SAE-PK: No PW available for K_AP fingerprint check");
+ return false;
+ }
+
+ /* Fingerprint = L(Hash(SSID || M || K_AP), 0, 8*Sec + 5*Lambda - 2) */
+
+ hash_len = sae_ecc_prime_len_2_hash_len(tmp->prime_len);
+ hash_data_len = tmp->ssid_len + m_len + k_ap_len;
+ hash_data = os_malloc(hash_data_len);
+ if (!hash_data)
+ return false;
+ pos = hash_data;
+ os_memcpy(pos, tmp->ssid, tmp->ssid_len);
+ pos += tmp->ssid_len;
+ os_memcpy(pos, m, m_len);
+ pos += m_len;
+ os_memcpy(pos, k_ap, k_ap_len);
+
+ wpa_hexdump_key(MSG_DEBUG, "SAE-PK: SSID || M || K_AP",
+ hash_data, hash_data_len);
+ res = sae_hash(hash_len, hash_data, hash_data_len, hash);
+ bin_clear_free(hash_data, hash_data_len);
+ if (res < 0)
+ return false;
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Hash(SSID || M || K_AP)",
+ hash, hash_len);
+
+ wpa_hexdump_key(MSG_DEBUG, "SAE-PK: PW", tmp->pw, tmp->pw_len);
+ sec = (tmp->pw[0] >> 6) + 2;
+ fingerprint_bits = 8 * sec + 5 * tmp->lambda - 2;
+ wpa_printf(MSG_DEBUG, "SAE-PK: Sec=%zu Lambda=%zu fingerprint_bits=%zu",
+ sec, tmp->lambda, fingerprint_bits);
+ if (fingerprint_bits > hash_len * 8) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: Not enough hash output bits for the fingerprint");
+ return false;
+ }
+ fingerprint_bytes = (fingerprint_bits + 7) / 8;
+ if (fingerprint_bits % 8) {
+ size_t extra;
+
+ /* Zero out the extra bits in the last octet */
+ extra = 8 - fingerprint_bits % 8;
+ pos = &hash[fingerprint_bits / 8];
+ *pos = (*pos >> extra) << extra;
+ }
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Fingerprint", hash, fingerprint_bytes);
+
+ fingerprint_exp = os_zalloc(sec + tmp->pw_len);
+ if (!fingerprint_exp)
+ return false;
+ pos = fingerprint_exp + sec;
+ for (i = 0; i < tmp->pw_len; i++) {
+ u8 next = i + 1 < tmp->pw_len ? tmp->pw[i + 1] : 0;
+
+ *pos++ = tmp->pw[i] << 2 | next >> 6;
+ }
+
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Fingerprint_Expected",
+ fingerprint_exp, fingerprint_bytes);
+ res = os_memcmp_const(hash, fingerprint_exp, fingerprint_bytes);
+ bin_clear_free(fingerprint_exp, tmp->pw_len);
+
+ if (res) {
+ wpa_printf(MSG_DEBUG, "SAE-PK: K_AP fingerprint mismatch");
+ return false;
+ }
+
+ wpa_printf(MSG_DEBUG, "SAE-PK: Valid K_AP fingerprint");
+ return true;
+}
+
+
+int sae_check_confirm_pk(struct sae_data *sae, const u8 *ies, size_t ies_len)
+{
+ struct sae_temporary_data *tmp = sae->tmp;
+ const u8 *sae_pk, *pos, *end, *encr_mod, *k_ap, *key_auth;
+ u8 m[SAE_PK_M_LEN];
+ size_t k_ap_len, key_auth_len;
+ struct crypto_ec_key *key;
+ int res;
+ u8 hash[SAE_MAX_HASH_LEN];
+ size_t hash_len;
+ int group;
+
+ if (!tmp)
+ return -1;
+ if (!tmp->pk || tmp->ap_pk)
+ return 0;
+
+ if (tmp->kek_len != 32 && tmp->kek_len != 48 && tmp->kek_len != 64) {
+ wpa_printf(MSG_INFO, "SAE-PK: No KEK available for confirm");
+ return -1;
+ }
+
+ if (!tmp->ec) {
+ /* Only ECC groups are supported for SAE-PK in the current
+ * implementation. */
+ wpa_printf(MSG_INFO,
+ "SAE-PK: SAE commit did not use an ECC group");
+ return -1;
+ }
+
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Received confirm IEs", ies, ies_len);
+ sae_pk = get_vendor_ie(ies, ies_len, SAE_PK_IE_VENDOR_TYPE);
+ if (!sae_pk) {
+ wpa_printf(MSG_INFO, "SAE-PK: No SAE-PK element included");
+ return -1;
+ }
+ /* TODO: Fragment reassembly */
+ pos = sae_pk + 2;
+ end = pos + sae_pk[1];
+
+ if (end - pos < 4 + 1 + SAE_PK_M_LEN + AES_BLOCK_SIZE) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: No room for EncryptedModifier in SAE-PK element");
+ return -1;
+ }
+ pos += 4;
+ if (*pos != SAE_PK_M_LEN + AES_BLOCK_SIZE) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: Unexpected EncryptedModifier length %u",
+ *pos);
+ return -1;
+ }
+ pos++;
+ encr_mod = pos;
+ pos += SAE_PK_M_LEN + AES_BLOCK_SIZE;
+
+ if (end - pos < 4 || pos[0] != WLAN_EID_EXTENSION || pos[1] < 2 ||
+ pos[1] > end - pos - 2 ||
+ pos[2] != WLAN_EID_EXT_FILS_PUBLIC_KEY) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: No FILS Public Key element in SAE-PK element");
+ return -1;
+ }
+ if (pos[3] != 3) {
+ wpa_printf(MSG_INFO, "SAE-PK: Unsupported public key type %u",
+ pos[3]);
+ return -1;
+ }
+ k_ap_len = pos[1] - 2;
+ pos += 4;
+ k_ap = pos;
+ pos += k_ap_len;
+
+ if (end - pos < 4 || pos[0] != WLAN_EID_EXTENSION || pos[1] < 1 ||
+ pos[1] > end - pos - 2 ||
+ pos[2] != WLAN_EID_EXT_FILS_KEY_CONFIRM) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: No FILS Key Confirm element in SAE-PK element");
+ return -1;
+ }
+ key_auth_len = pos[1] - 1;
+ pos += 3;
+ key_auth = pos;
+ pos += key_auth_len;
+
+ if (pos < end) {
+ wpa_hexdump(MSG_DEBUG,
+ "SAE-PK: Extra data at the end of SAE-PK element",
+ pos, end - pos);
+ }
+
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: EncryptedModifier",
+ encr_mod, SAE_PK_M_LEN + AES_BLOCK_SIZE);
+
+ if (aes_siv_decrypt(tmp->kek, tmp->kek_len,
+ encr_mod, SAE_PK_M_LEN + AES_BLOCK_SIZE,
+ 0, NULL, NULL, m) < 0) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: Failed to decrypt EncryptedModifier");
+ return -1;
+ }
+ wpa_hexdump_key(MSG_DEBUG, "SAE-PK: Modifier M", m, SAE_PK_M_LEN);
+
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Received K_AP", k_ap, k_ap_len);
+ /* TODO: Check against the public key, if one is stored in the network
+ * profile */
+
+ if (!sae_pk_valid_fingerprint(sae, m, SAE_PK_M_LEN, k_ap, k_ap_len))
+ return -1;
+
+ key = crypto_ec_key_parse_pub(k_ap, k_ap_len);
+ if (!key) {
+ wpa_printf(MSG_INFO, "SAE-PK: Failed to parse K_AP");
+ return -1;
+ }
+
+ group = crypto_ec_key_group(key);
+ /* TODO: Could support alternative groups as long as the combination
+ * meets the requirements. */
+ if (group != sae->group) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: K_AP group %d does not match SAE group %d",
+ group, sae->group);
+ crypto_ec_key_deinit(key);
+ return -1;
+ }
+
+ wpa_hexdump(MSG_DEBUG, "SAE-PK: Received KeyAuth",
+ key_auth, key_auth_len);
+
+ hash_len = sae_ecc_prime_len_2_hash_len(tmp->prime_len);
+ if (sae_pk_hash_sig_data(sae, hash_len, false, m, SAE_PK_M_LEN,
+ k_ap, k_ap_len, hash) < 0) {
+ crypto_ec_key_deinit(key);
+ return -1;
+ }
+
+ res = crypto_ec_key_verify_signature(key, hash, hash_len,
+ key_auth, key_auth_len);
+ crypto_ec_key_deinit(key);
+
+ if (res != 1) {
+ wpa_printf(MSG_INFO,
+ "SAE-PK: Invalid or incorrect signature in KeyAuth");
+ return -1;
+ }
+
+ wpa_printf(MSG_DEBUG, "SAE-PK: Valid KeyAuth signature received");
+
+ /* TODO: Store validated public key into network profile */
+
+ return 0;
+}
projects / thirdparty / hostap.git / commitdiff
