+++ /dev/null
-/*
- * EAP peer method: EAP-pwd (RFC 5931)
- * Copyright (c) 2010, Dan Harkins <dharkins@lounge.org>
- *
- * This software may be distributed under the terms of the BSD license.
- * See README for more details.
- */
-
-#include "includes.h"
-
-#include "common.h"
-#include "crypto/sha256.h"
-#include "crypto/ms_funcs.h"
-#include "eap_peer/eap_i.h"
-#include "eap_common/eap_pwd_common.h"
-
-
-struct eap_pwd_data {
- enum {
- PWD_ID_Req, PWD_Commit_Req, PWD_Confirm_Req,
- SUCCESS_ON_FRAG_COMPLETION, SUCCESS, FAILURE
- } state;
- u8 *id_peer;
- size_t id_peer_len;
- u8 *id_server;
- size_t id_server_len;
- u8 *password;
- size_t password_len;
- int password_hash;
- u16 group_num;
- EAP_PWD_group *grp;
-
- struct wpabuf *inbuf;
- size_t in_frag_pos;
- struct wpabuf *outbuf;
- size_t out_frag_pos;
- size_t mtu;
-
- BIGNUM *k;
- BIGNUM *private_value;
- BIGNUM *server_scalar;
- BIGNUM *my_scalar;
- EC_POINT *my_element;
- EC_POINT *server_element;
-
- u8 msk[EAP_MSK_LEN];
- u8 emsk[EAP_EMSK_LEN];
- u8 session_id[1 + SHA256_MAC_LEN];
-
- BN_CTX *bnctx;
-};
-
-
-#ifndef CONFIG_NO_STDOUT_DEBUG
-static const char * eap_pwd_state_txt(int state)
-{
- switch (state) {
- case PWD_ID_Req:
- return "PWD-ID-Req";
- case PWD_Commit_Req:
- return "PWD-Commit-Req";
- case PWD_Confirm_Req:
- return "PWD-Confirm-Req";
- case SUCCESS_ON_FRAG_COMPLETION:
- return "SUCCESS_ON_FRAG_COMPLETION";
- case SUCCESS:
- return "SUCCESS";
- case FAILURE:
- return "FAILURE";
- default:
- return "PWD-UNK";
- }
-}
-#endif /* CONFIG_NO_STDOUT_DEBUG */
-
-
-static void eap_pwd_state(struct eap_pwd_data *data, int state)
-{
- wpa_printf(MSG_DEBUG, "EAP-PWD: %s -> %s",
- eap_pwd_state_txt(data->state), eap_pwd_state_txt(state));
- data->state = state;
-}
-
-
-static void * eap_pwd_init(struct eap_sm *sm)
-{
- struct eap_pwd_data *data;
- const u8 *identity, *password;
- size_t identity_len, password_len;
- int fragment_size;
- int pwhash;
-
- password = eap_get_config_password2(sm, &password_len, &pwhash);
- if (password == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: No password configured!");
- return NULL;
- }
-
- identity = eap_get_config_identity(sm, &identity_len);
- if (identity == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: No identity configured!");
- return NULL;
- }
-
- if ((data = os_zalloc(sizeof(*data))) == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: memory allocation data fail");
- return NULL;
- }
-
- if ((data->bnctx = BN_CTX_new()) == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: bn context allocation fail");
- os_free(data);
- return NULL;
- }
-
- if ((data->id_peer = os_malloc(identity_len)) == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail");
- BN_CTX_free(data->bnctx);
- os_free(data);
- return NULL;
- }
-
- os_memcpy(data->id_peer, identity, identity_len);
- data->id_peer_len = identity_len;
-
- if ((data->password = os_malloc(password_len)) == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: memory allocation psk fail");
- BN_CTX_free(data->bnctx);
- bin_clear_free(data->id_peer, data->id_peer_len);
- os_free(data);
- return NULL;
- }
- os_memcpy(data->password, password, password_len);
- data->password_len = password_len;
- data->password_hash = pwhash;
-
- data->out_frag_pos = data->in_frag_pos = 0;
- data->inbuf = data->outbuf = NULL;
- fragment_size = eap_get_config_fragment_size(sm);
- if (fragment_size <= 0)
- data->mtu = 1020; /* default from RFC 5931 */
- else
- data->mtu = fragment_size;
-
- data->state = PWD_ID_Req;
-
- return data;
-}
-
-
-static void eap_pwd_deinit(struct eap_sm *sm, void *priv)
-{
- struct eap_pwd_data *data = priv;
-
- BN_clear_free(data->private_value);
- BN_clear_free(data->server_scalar);
- BN_clear_free(data->my_scalar);
- BN_clear_free(data->k);
- BN_CTX_free(data->bnctx);
- EC_POINT_clear_free(data->my_element);
- EC_POINT_clear_free(data->server_element);
- bin_clear_free(data->id_peer, data->id_peer_len);
- bin_clear_free(data->id_server, data->id_server_len);
- bin_clear_free(data->password, data->password_len);
- if (data->grp) {
- EC_GROUP_free(data->grp->group);
- EC_POINT_clear_free(data->grp->pwe);
- BN_clear_free(data->grp->order);
- BN_clear_free(data->grp->prime);
- os_free(data->grp);
- }
- wpabuf_free(data->inbuf);
- wpabuf_free(data->outbuf);
- bin_clear_free(data, sizeof(*data));
-}
-
-
-static u8 * eap_pwd_getkey(struct eap_sm *sm, void *priv, size_t *len)
-{
- struct eap_pwd_data *data = priv;
- u8 *key;
-
- if (data->state != SUCCESS)
- return NULL;
-
- key = os_malloc(EAP_MSK_LEN);
- if (key == NULL)
- return NULL;
-
- os_memcpy(key, data->msk, EAP_MSK_LEN);
- *len = EAP_MSK_LEN;
-
- return key;
-}
-
-
-static u8 * eap_pwd_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
-{
- struct eap_pwd_data *data = priv;
- u8 *id;
-
- if (data->state != SUCCESS)
- return NULL;
-
- id = os_malloc(1 + SHA256_MAC_LEN);
- if (id == NULL)
- return NULL;
-
- os_memcpy(id, data->session_id, 1 + SHA256_MAC_LEN);
- *len = 1 + SHA256_MAC_LEN;
-
- return id;
-}
-
-
-static void
-eap_pwd_perform_id_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
- struct eap_method_ret *ret,
- const struct wpabuf *reqData,
- const u8 *payload, size_t payload_len)
-{
- struct eap_pwd_id *id;
- const u8 *password;
- size_t password_len;
- u8 pwhashhash[16];
- int res;
-
- if (data->state != PWD_ID_Req) {
- ret->ignore = TRUE;
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- if (payload_len < sizeof(struct eap_pwd_id)) {
- ret->ignore = TRUE;
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- id = (struct eap_pwd_id *) payload;
- data->group_num = be_to_host16(id->group_num);
- wpa_printf(MSG_DEBUG,
- "EAP-PWD: Server EAP-pwd-ID proposal: group=%u random=%u prf=%u prep=%u",
- data->group_num, id->random_function, id->prf, id->prep);
- if ((id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) ||
- (id->prf != EAP_PWD_DEFAULT_PRF)) {
- ret->ignore = TRUE;
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- if (id->prep != EAP_PWD_PREP_NONE &&
- id->prep != EAP_PWD_PREP_MS) {
- wpa_printf(MSG_DEBUG,
- "EAP-PWD: Unsupported password pre-processing technique (Prep=%u)",
- id->prep);
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- if (id->prep == EAP_PWD_PREP_NONE && data->password_hash) {
- wpa_printf(MSG_DEBUG,
- "EAP-PWD: Unhashed password not available");
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- wpa_printf(MSG_DEBUG, "EAP-PWD (peer): using group %d",
- data->group_num);
-
- data->id_server = os_malloc(payload_len - sizeof(struct eap_pwd_id));
- if (data->id_server == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail");
- eap_pwd_state(data, FAILURE);
- return;
- }
- data->id_server_len = payload_len - sizeof(struct eap_pwd_id);
- os_memcpy(data->id_server, id->identity, data->id_server_len);
- wpa_hexdump_ascii(MSG_INFO, "EAP-PWD (peer): server sent id of",
- data->id_server, data->id_server_len);
-
- data->grp = os_zalloc(sizeof(EAP_PWD_group));
- if (data->grp == NULL) {
- wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for "
- "group");
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- if (id->prep == EAP_PWD_PREP_MS) {
-#ifdef CONFIG_FIPS
- wpa_printf(MSG_ERROR,
- "EAP-PWD (peer): MS password hash not supported in FIPS mode");
- eap_pwd_state(data, FAILURE);
- return;
-#else /* CONFIG_FIPS */
- if (data->password_hash) {
- res = hash_nt_password_hash(data->password, pwhashhash);
- } else {
- u8 pwhash[16];
-
- res = nt_password_hash(data->password,
- data->password_len, pwhash);
- if (res == 0)
- res = hash_nt_password_hash(pwhash, pwhashhash);
- os_memset(pwhash, 0, sizeof(pwhash));
- }
-
- if (res) {
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- password = pwhashhash;
- password_len = sizeof(pwhashhash);
-#endif /* CONFIG_FIPS */
- } else {
- password = data->password;
- password_len = data->password_len;
- }
-
- /* compute PWE */
- res = compute_password_element(data->grp, data->group_num,
- password, password_len,
- data->id_server, data->id_server_len,
- data->id_peer, data->id_peer_len,
- id->token);
- os_memset(pwhashhash, 0, sizeof(pwhashhash));
- if (res) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute PWE");
- eap_pwd_state(data, FAILURE);
- return;
- }
-
- wpa_printf(MSG_DEBUG, "EAP-PWD (peer): computed %d bit PWE...",
- BN_num_bits(data->grp->prime));
-
- data->outbuf = wpabuf_alloc(sizeof(struct eap_pwd_id) +
- data->id_peer_len);
- if (data->outbuf == NULL) {
- eap_pwd_state(data, FAILURE);
- return;
- }
- wpabuf_put_be16(data->outbuf, data->group_num);
- wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_RAND_FUNC);
- wpabuf_put_u8(data->outbuf, EAP_PWD_DEFAULT_PRF);
- wpabuf_put_data(data->outbuf, id->token, sizeof(id->token));
- wpabuf_put_u8(data->outbuf, EAP_PWD_PREP_NONE);
- wpabuf_put_data(data->outbuf, data->id_peer, data->id_peer_len);
-
- eap_pwd_state(data, PWD_Commit_Req);
-}
-
-
-static void
-eap_pwd_perform_commit_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
- struct eap_method_ret *ret,
- const struct wpabuf *reqData,
- const u8 *payload, size_t payload_len)
-{
- EC_POINT *K = NULL, *point = NULL;
- BIGNUM *mask = NULL, *x = NULL, *y = NULL, *cofactor = NULL;
- u16 offset;
- u8 *ptr, *scalar = NULL, *element = NULL;
- size_t prime_len, order_len;
-
- if (data->state != PWD_Commit_Req) {
- ret->ignore = TRUE;
- goto fin;
- }
-
- prime_len = BN_num_bytes(data->grp->prime);
- order_len = BN_num_bytes(data->grp->order);
-
- if (payload_len != 2 * prime_len + order_len) {
- wpa_printf(MSG_INFO,
- "EAP-pwd: Unexpected Commit payload length %u (expected %u)",
- (unsigned int) payload_len,
- (unsigned int) (2 * prime_len + order_len));
- goto fin;
- }
-
- if (((data->private_value = BN_new()) == NULL) ||
- ((data->my_element = EC_POINT_new(data->grp->group)) == NULL) ||
- ((cofactor = BN_new()) == NULL) ||
- ((data->my_scalar = BN_new()) == NULL) ||
- ((mask = BN_new()) == NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): scalar allocation fail");
- goto fin;
- }
-
- if (!EC_GROUP_get_cofactor(data->grp->group, cofactor, NULL)) {
- wpa_printf(MSG_INFO, "EAP-pwd (peer): unable to get cofactor "
- "for curve");
- goto fin;
- }
-
- if (BN_rand_range(data->private_value, data->grp->order) != 1 ||
- BN_rand_range(mask, data->grp->order) != 1 ||
- BN_add(data->my_scalar, data->private_value, mask) != 1 ||
- BN_mod(data->my_scalar, data->my_scalar, data->grp->order,
- data->bnctx) != 1) {
- wpa_printf(MSG_INFO,
- "EAP-pwd (peer): unable to get randomness");
- goto fin;
- }
-
- if (!EC_POINT_mul(data->grp->group, data->my_element, NULL,
- data->grp->pwe, mask, data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): element allocation "
- "fail");
- eap_pwd_state(data, FAILURE);
- goto fin;
- }
-
- if (!EC_POINT_invert(data->grp->group, data->my_element, data->bnctx))
- {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): element inversion fail");
- goto fin;
- }
-
- if (((x = BN_new()) == NULL) ||
- ((y = BN_new()) == NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): point allocation fail");
- goto fin;
- }
-
- /* process the request */
- if (((data->server_scalar = BN_new()) == NULL) ||
- ((data->k = BN_new()) == NULL) ||
- ((K = EC_POINT_new(data->grp->group)) == NULL) ||
- ((point = EC_POINT_new(data->grp->group)) == NULL) ||
- ((data->server_element = EC_POINT_new(data->grp->group)) == NULL))
- {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): peer data allocation "
- "fail");
- goto fin;
- }
-
- /* element, x then y, followed by scalar */
- ptr = (u8 *) payload;
- BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), x);
- ptr += BN_num_bytes(data->grp->prime);
- BN_bin2bn(ptr, BN_num_bytes(data->grp->prime), y);
- ptr += BN_num_bytes(data->grp->prime);
- BN_bin2bn(ptr, BN_num_bytes(data->grp->order), data->server_scalar);
- if (!EC_POINT_set_affine_coordinates_GFp(data->grp->group,
- data->server_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): setting peer element "
- "fail");
- goto fin;
- }
-
- /* check to ensure server's element is not in a small sub-group */
- if (BN_cmp(cofactor, BN_value_one())) {
- if (!EC_POINT_mul(data->grp->group, point, NULL,
- data->server_element, cofactor, NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): cannot multiply "
- "server element by order!\n");
- goto fin;
- }
- if (EC_POINT_is_at_infinity(data->grp->group, point)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): server element "
- "is at infinity!\n");
- goto fin;
- }
- }
-
- /* compute the shared key, k */
- if ((!EC_POINT_mul(data->grp->group, K, NULL, data->grp->pwe,
- data->server_scalar, data->bnctx)) ||
- (!EC_POINT_add(data->grp->group, K, K, data->server_element,
- data->bnctx)) ||
- (!EC_POINT_mul(data->grp->group, K, NULL, K, data->private_value,
- data->bnctx))) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): computing shared key "
- "fail");
- goto fin;
- }
-
- /* ensure that the shared key isn't in a small sub-group */
- if (BN_cmp(cofactor, BN_value_one())) {
- if (!EC_POINT_mul(data->grp->group, K, NULL, K, cofactor,
- NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): cannot multiply "
- "shared key point by order");
- goto fin;
- }
- }
-
- /*
- * This check is strictly speaking just for the case above where
- * co-factor > 1 but it was suggested that even though this is probably
- * never going to happen it is a simple and safe check "just to be
- * sure" so let's be safe.
- */
- if (EC_POINT_is_at_infinity(data->grp->group, K)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): shared key point is at "
- "infinity!\n");
- goto fin;
- }
-
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, K, data->k,
- NULL, data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to extract "
- "shared secret from point");
- goto fin;
- }
-
- /* now do the response */
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
- data->my_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): point assignment fail");
- goto fin;
- }
-
- if (((scalar = os_malloc(BN_num_bytes(data->grp->order))) == NULL) ||
- ((element = os_malloc(BN_num_bytes(data->grp->prime) * 2)) ==
- NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): data allocation fail");
- goto fin;
- }
-
- /*
- * bignums occupy as little memory as possible so one that is
- * sufficiently smaller than the prime or order might need pre-pending
- * with zeros.
- */
- os_memset(scalar, 0, BN_num_bytes(data->grp->order));
- os_memset(element, 0, BN_num_bytes(data->grp->prime) * 2);
- offset = BN_num_bytes(data->grp->order) -
- BN_num_bytes(data->my_scalar);
- BN_bn2bin(data->my_scalar, scalar + offset);
-
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x);
- BN_bn2bin(x, element + offset);
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y);
- BN_bn2bin(y, element + BN_num_bytes(data->grp->prime) + offset);
-
- data->outbuf = wpabuf_alloc(BN_num_bytes(data->grp->order) +
- 2 * BN_num_bytes(data->grp->prime));
- if (data->outbuf == NULL)
- goto fin;
-
- /* we send the element as (x,y) follwed by the scalar */
- wpabuf_put_data(data->outbuf, element,
- 2 * BN_num_bytes(data->grp->prime));
- wpabuf_put_data(data->outbuf, scalar, BN_num_bytes(data->grp->order));
-
-fin:
- os_free(scalar);
- os_free(element);
- BN_clear_free(x);
- BN_clear_free(y);
- BN_clear_free(mask);
- BN_clear_free(cofactor);
- EC_POINT_clear_free(K);
- EC_POINT_clear_free(point);
- if (data->outbuf == NULL)
- eap_pwd_state(data, FAILURE);
- else
- eap_pwd_state(data, PWD_Confirm_Req);
-}
-
-
-static void
-eap_pwd_perform_confirm_exchange(struct eap_sm *sm, struct eap_pwd_data *data,
- struct eap_method_ret *ret,
- const struct wpabuf *reqData,
- const u8 *payload, size_t payload_len)
-{
- BIGNUM *x = NULL, *y = NULL;
- struct crypto_hash *hash;
- u32 cs;
- u16 grp;
- u8 conf[SHA256_MAC_LEN], *cruft = NULL, *ptr;
- int offset;
-
- if (data->state != PWD_Confirm_Req) {
- ret->ignore = TRUE;
- goto fin;
- }
-
- if (payload_len != SHA256_MAC_LEN) {
- wpa_printf(MSG_INFO,
- "EAP-pwd: Unexpected Confirm payload length %u (expected %u)",
- (unsigned int) payload_len, SHA256_MAC_LEN);
- goto fin;
- }
-
- /*
- * first build up the ciphersuite which is group | random_function |
- * prf
- */
- grp = htons(data->group_num);
- ptr = (u8 *) &cs;
- os_memcpy(ptr, &grp, sizeof(u16));
- ptr += sizeof(u16);
- *ptr = EAP_PWD_DEFAULT_RAND_FUNC;
- ptr += sizeof(u8);
- *ptr = EAP_PWD_DEFAULT_PRF;
-
- /* each component of the cruft will be at most as big as the prime */
- if (((cruft = os_malloc(BN_num_bytes(data->grp->prime))) == NULL) ||
- ((x = BN_new()) == NULL) || ((y = BN_new()) == NULL)) {
- wpa_printf(MSG_INFO, "EAP-PWD (server): confirm allocation "
- "fail");
- goto fin;
- }
-
- /*
- * server's commit is H(k | server_element | server_scalar |
- * peer_element | peer_scalar | ciphersuite)
- */
- hash = eap_pwd_h_init();
- if (hash == NULL)
- goto fin;
-
- /*
- * zero the memory each time because this is mod prime math and some
- * value may start with a few zeros and the previous one did not.
- */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k);
- BN_bn2bin(data->k, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* server element: x, y */
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
- data->server_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
- "assignment fail");
- goto fin;
- }
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x);
- BN_bn2bin(x, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y);
- BN_bn2bin(y, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* server scalar */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->order) -
- BN_num_bytes(data->server_scalar);
- BN_bn2bin(data->server_scalar, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order));
-
- /* my element: x, y */
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
- data->my_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
- "assignment fail");
- goto fin;
- }
-
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x);
- BN_bn2bin(x, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y);
- BN_bn2bin(y, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* my scalar */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->order) -
- BN_num_bytes(data->my_scalar);
- BN_bn2bin(data->my_scalar, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order));
-
- /* the ciphersuite */
- eap_pwd_h_update(hash, (u8 *) &cs, sizeof(u32));
-
- /* random function fin */
- eap_pwd_h_final(hash, conf);
-
- ptr = (u8 *) payload;
- if (os_memcmp_const(conf, ptr, SHA256_MAC_LEN)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm did not verify");
- goto fin;
- }
-
- wpa_printf(MSG_DEBUG, "EAP-pwd (peer): confirm verified");
-
- /*
- * compute confirm:
- * H(k | peer_element | peer_scalar | server_element | server_scalar |
- * ciphersuite)
- */
- hash = eap_pwd_h_init();
- if (hash == NULL)
- goto fin;
-
- /* k */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(data->k);
- BN_bn2bin(data->k, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* my element */
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
- data->my_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm point "
- "assignment fail");
- goto fin;
- }
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x);
- BN_bn2bin(x, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y);
- BN_bn2bin(y, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* my scalar */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->order) -
- BN_num_bytes(data->my_scalar);
- BN_bn2bin(data->my_scalar, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order));
-
- /* server element: x, y */
- if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
- data->server_element, x, y,
- data->bnctx)) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): confirm point "
- "assignment fail");
- goto fin;
- }
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(x);
- BN_bn2bin(x, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->prime) - BN_num_bytes(y);
- BN_bn2bin(y, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->prime));
-
- /* server scalar */
- os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
- offset = BN_num_bytes(data->grp->order) -
- BN_num_bytes(data->server_scalar);
- BN_bn2bin(data->server_scalar, cruft + offset);
- eap_pwd_h_update(hash, cruft, BN_num_bytes(data->grp->order));
-
- /* the ciphersuite */
- eap_pwd_h_update(hash, (u8 *) &cs, sizeof(u32));
-
- /* all done */
- eap_pwd_h_final(hash, conf);
-
- if (compute_keys(data->grp, data->bnctx, data->k,
- data->my_scalar, data->server_scalar, conf, ptr,
- &cs, data->msk, data->emsk, data->session_id) < 0) {
- wpa_printf(MSG_INFO, "EAP-PWD (peer): unable to compute MSK | "
- "EMSK");
- goto fin;
- }
-
- data->outbuf = wpabuf_alloc(SHA256_MAC_LEN);
- if (data->outbuf == NULL)
- goto fin;
-
- wpabuf_put_data(data->outbuf, conf, SHA256_MAC_LEN);
-
-fin:
- if (data->grp)
- bin_clear_free(cruft, BN_num_bytes(data->grp->prime));
- BN_clear_free(x);
- BN_clear_free(y);
- if (data->outbuf == NULL) {
- ret->methodState = METHOD_DONE;
- ret->decision = DECISION_FAIL;
- eap_pwd_state(data, FAILURE);
- } else {
- eap_pwd_state(data, SUCCESS_ON_FRAG_COMPLETION);
- }
-}
-
-
-static struct wpabuf *
-eap_pwd_process(struct eap_sm *sm, void *priv, struct eap_method_ret *ret,
- const struct wpabuf *reqData)
-{
- struct eap_pwd_data *data = priv;
- struct wpabuf *resp = NULL;
- const u8 *pos, *buf;
- size_t len;
- u16 tot_len = 0;
- u8 lm_exch;
-
- pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, reqData, &len);
- if ((pos == NULL) || (len < 1)) {
- wpa_printf(MSG_DEBUG, "EAP-pwd: Got a frame but pos is %s and "
- "len is %d",
- pos == NULL ? "NULL" : "not NULL", (int) len);
- ret->ignore = TRUE;
- return NULL;
- }
-
- ret->ignore = FALSE;
- ret->methodState = METHOD_MAY_CONT;
- ret->decision = DECISION_FAIL;
- ret->allowNotifications = FALSE;
-
- lm_exch = *pos;
- pos++; /* skip over the bits and the exch */
- len--;
-
- /*
- * we're fragmenting so send out the next fragment
- */
- if (data->out_frag_pos) {
- /*
- * this should be an ACK
- */
- if (len)
- wpa_printf(MSG_INFO, "Bad Response! Fragmenting but "
- "not an ACK");
-
- wpa_printf(MSG_DEBUG, "EAP-pwd: Got an ACK for a fragment");
- /*
- * check if there are going to be more fragments
- */
- len = wpabuf_len(data->outbuf) - data->out_frag_pos;
- if ((len + EAP_PWD_HDR_SIZE) > data->mtu) {
- len = data->mtu - EAP_PWD_HDR_SIZE;
- EAP_PWD_SET_MORE_BIT(lm_exch);
- }
- resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
- EAP_PWD_HDR_SIZE + len,
- EAP_CODE_RESPONSE, eap_get_id(reqData));
- if (resp == NULL) {
- wpa_printf(MSG_INFO, "Unable to allocate memory for "
- "next fragment!");
- return NULL;
- }
- wpabuf_put_u8(resp, lm_exch);
- buf = wpabuf_head_u8(data->outbuf);
- wpabuf_put_data(resp, buf + data->out_frag_pos, len);
- data->out_frag_pos += len;
- /*
- * this is the last fragment so get rid of the out buffer
- */
- if (data->out_frag_pos >= wpabuf_len(data->outbuf)) {
- wpabuf_free(data->outbuf);
- data->outbuf = NULL;
- data->out_frag_pos = 0;
- }
- wpa_printf(MSG_DEBUG, "EAP-pwd: Send %s fragment of %d bytes",
- data->out_frag_pos == 0 ? "last" : "next",
- (int) len);
- if (data->state == SUCCESS_ON_FRAG_COMPLETION) {
- ret->methodState = METHOD_DONE;
- ret->decision = DECISION_UNCOND_SUCC;
- eap_pwd_state(data, SUCCESS);
- }
- return resp;
- }
-
- /*
- * see if this is a fragment that needs buffering
- *
- * if it's the first fragment there'll be a length field
- */
- if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) {
- if (len < 2) {
- wpa_printf(MSG_DEBUG,
- "EAP-pwd: Frame too short to contain Total-Length field");
- ret->ignore = TRUE;
- return NULL;
- }
- tot_len = WPA_GET_BE16(pos);
- wpa_printf(MSG_DEBUG, "EAP-pwd: Incoming fragments whose "
- "total length = %d", tot_len);
- if (tot_len > 15000)
- return NULL;
- if (data->inbuf) {
- wpa_printf(MSG_DEBUG,
- "EAP-pwd: Unexpected new fragment start when previous fragment is still in use");
- ret->ignore = TRUE;
- return NULL;
- }
- data->inbuf = wpabuf_alloc(tot_len);
- if (data->inbuf == NULL) {
- wpa_printf(MSG_INFO, "Out of memory to buffer "
- "fragments!");
- return NULL;
- }
- data->in_frag_pos = 0;
- pos += sizeof(u16);
- len -= sizeof(u16);
- }
- /*
- * buffer and ACK the fragment
- */
- if (EAP_PWD_GET_MORE_BIT(lm_exch) || data->in_frag_pos) {
- data->in_frag_pos += len;
- if (data->in_frag_pos > wpabuf_size(data->inbuf)) {
- wpa_printf(MSG_INFO, "EAP-pwd: Buffer overflow attack "
- "detected (%d vs. %d)!",
- (int) data->in_frag_pos,
- (int) wpabuf_len(data->inbuf));
- wpabuf_free(data->inbuf);
- data->inbuf = NULL;
- data->in_frag_pos = 0;
- return NULL;
- }
- wpabuf_put_data(data->inbuf, pos, len);
- }
- if (EAP_PWD_GET_MORE_BIT(lm_exch)) {
- resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
- EAP_PWD_HDR_SIZE,
- EAP_CODE_RESPONSE, eap_get_id(reqData));
- if (resp != NULL)
- wpabuf_put_u8(resp, (EAP_PWD_GET_EXCHANGE(lm_exch)));
- wpa_printf(MSG_DEBUG, "EAP-pwd: ACKing a %d byte fragment",
- (int) len);
- return resp;
- }
- /*
- * we're buffering and this is the last fragment
- */
- if (data->in_frag_pos) {
- wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes",
- (int) len);
- pos = wpabuf_head_u8(data->inbuf);
- len = data->in_frag_pos;
- }
- wpa_printf(MSG_DEBUG, "EAP-pwd: processing frame: exch %d, len %d",
- EAP_PWD_GET_EXCHANGE(lm_exch), (int) len);
-
- switch (EAP_PWD_GET_EXCHANGE(lm_exch)) {
- case EAP_PWD_OPCODE_ID_EXCH:
- eap_pwd_perform_id_exchange(sm, data, ret, reqData,
- pos, len);
- break;
- case EAP_PWD_OPCODE_COMMIT_EXCH:
- eap_pwd_perform_commit_exchange(sm, data, ret, reqData,
- pos, len);
- break;
- case EAP_PWD_OPCODE_CONFIRM_EXCH:
- eap_pwd_perform_confirm_exchange(sm, data, ret, reqData,
- pos, len);
- break;
- default:
- wpa_printf(MSG_INFO, "EAP-pwd: Ignoring message with unknown "
- "opcode %d", lm_exch);
- break;
- }
- /*
- * if we buffered the just processed input now's the time to free it
- */
- if (data->in_frag_pos) {
- wpabuf_free(data->inbuf);
- data->inbuf = NULL;
- data->in_frag_pos = 0;
- }
-
- if (data->outbuf == NULL) {
- ret->methodState = METHOD_DONE;
- ret->decision = DECISION_FAIL;
- return NULL; /* generic failure */
- }
-
- /*
- * we have output! Do we need to fragment it?
- */
- lm_exch = EAP_PWD_GET_EXCHANGE(lm_exch);
- len = wpabuf_len(data->outbuf);
- if ((len + EAP_PWD_HDR_SIZE) > data->mtu) {
- resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD, data->mtu,
- EAP_CODE_RESPONSE, eap_get_id(reqData));
- /*
- * if so it's the first so include a length field
- */
- EAP_PWD_SET_LENGTH_BIT(lm_exch);
- EAP_PWD_SET_MORE_BIT(lm_exch);
- tot_len = len;
- /*
- * keep the packet at the MTU
- */
- len = data->mtu - EAP_PWD_HDR_SIZE - sizeof(u16);
- wpa_printf(MSG_DEBUG, "EAP-pwd: Fragmenting output, total "
- "length = %d", tot_len);
- } else {
- resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
- EAP_PWD_HDR_SIZE + len,
- EAP_CODE_RESPONSE, eap_get_id(reqData));
- }
- if (resp == NULL)
- return NULL;
-
- wpabuf_put_u8(resp, lm_exch);
- if (EAP_PWD_GET_LENGTH_BIT(lm_exch)) {
- wpabuf_put_be16(resp, tot_len);
- data->out_frag_pos += len;
- }
- buf = wpabuf_head_u8(data->outbuf);
- wpabuf_put_data(resp, buf, len);
- /*
- * if we're not fragmenting then there's no need to carry this around
- */
- if (data->out_frag_pos == 0) {
- wpabuf_free(data->outbuf);
- data->outbuf = NULL;
- data->out_frag_pos = 0;
- if (data->state == SUCCESS_ON_FRAG_COMPLETION) {
- ret->methodState = METHOD_DONE;
- ret->decision = DECISION_UNCOND_SUCC;
- eap_pwd_state(data, SUCCESS);
- }
- }
-
- return resp;
-}
-
-
-static Boolean eap_pwd_key_available(struct eap_sm *sm, void *priv)
-{
- struct eap_pwd_data *data = priv;
- return data->state == SUCCESS;
-}
-
-
-static u8 * eap_pwd_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
-{
- struct eap_pwd_data *data = priv;
- u8 *key;
-
- if (data->state != SUCCESS)
- return NULL;
-
- if ((key = os_malloc(EAP_EMSK_LEN)) == NULL)
- return NULL;
-
- os_memcpy(key, data->emsk, EAP_EMSK_LEN);
- *len = EAP_EMSK_LEN;
-
- return key;
-}
-
-
-int eap_peer_pwd_register(void)
-{
- struct eap_method *eap;
-
- eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
- EAP_VENDOR_IETF, EAP_TYPE_PWD, "PWD");
- if (eap == NULL)
- return -1;
-
- eap->init = eap_pwd_init;
- eap->deinit = eap_pwd_deinit;
- eap->process = eap_pwd_process;
- eap->isKeyAvailable = eap_pwd_key_available;
- eap->getKey = eap_pwd_getkey;
- eap->getSessionId = eap_pwd_get_session_id;
- eap->get_emsk = eap_pwd_get_emsk;
-
- return eap_peer_method_register(eap);
-}
projects / mech_eap.git / blobdiff