diff options
Diffstat (limited to 'src/eap_peer/eap_pwd.c')
| -rw-r--r-- | src/eap_peer/eap_pwd.c | 922 |
1 files changed, 922 insertions, 0 deletions
diff --git a/src/eap_peer/eap_pwd.c b/src/eap_peer/eap_pwd.c new file mode 100644 index 0000000000000..267d0a5c69768 --- /dev/null +++ b/src/eap_peer/eap_pwd.c @@ -0,0 +1,922 @@ +/* + * 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 "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, FAILURE + } state; + u8 *id_peer; + size_t id_peer_len; + u8 *id_server; + size_t id_server_len; + u8 *password; + size_t password_len; + 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]; + + 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: + 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; + + password = eap_get_config_password(sm, &password_len); + 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); + os_free(data->id_peer); + os_free(data); + return NULL; + } + os_memcpy(data->password, password, password_len); + data->password_len = password_len; + + data->out_frag_pos = data->in_frag_pos = 0; + data->inbuf = data->outbuf = NULL; + data->mtu = 1020; /* default from RFC 5931, make it configurable! */ + + 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_free(data->private_value); + BN_free(data->server_scalar); + BN_free(data->my_scalar); + BN_free(data->k); + BN_CTX_free(data->bnctx); + EC_POINT_free(data->my_element); + EC_POINT_free(data->server_element); + os_free(data->id_peer); + os_free(data->id_server); + os_free(data->password); + if (data->grp) { + EC_GROUP_free(data->grp->group); + EC_POINT_free(data->grp->pwe); + BN_free(data->grp->order); + BN_free(data->grp->prime); + os_free(data->grp); + } + os_free(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 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; + + 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); + if ((id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) || + (id->prf != EAP_PWD_DEFAULT_PRF)) { + ret->ignore = TRUE; + 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); + + if ((data->grp = (EAP_PWD_group *) os_malloc(sizeof(EAP_PWD_group))) == + NULL) { + wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for " + "group"); + eap_pwd_state(data, FAILURE); + return; + } + + /* compute PWE */ + if (compute_password_element(data->grp, data->group_num, + data->password, data->password_len, + data->id_server, data->id_server_len, + data->id_peer, data->id_peer_len, + id->token)) { + 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; + + 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; + } + + BN_rand_range(data->private_value, data->grp->order); + BN_rand_range(mask, data->grp->order); + BN_add(data->my_scalar, data->private_value, mask); + BN_mod(data->my_scalar, data->my_scalar, data->grp->order, + data->bnctx); + + 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; + } + BN_free(mask); + + 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_free(x); + BN_free(y); + BN_free(cofactor); + EC_POINT_free(K); + EC_POINT_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; + + /* + * 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(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) < 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: + os_free(cruft); + BN_free(x); + BN_free(y); + ret->methodState = METHOD_DONE; + if (data->outbuf == NULL) { + ret->decision = DECISION_FAIL; + eap_pwd_state(data, FAILURE); + } else { + ret->decision = DECISION_UNCOND_SUCC; + eap_pwd_state(data, SUCCESS); + } +} + + +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); + 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)) { + tot_len = WPA_GET_BE16(pos); + wpa_printf(MSG_DEBUG, "EAP-pwd: Incoming fragments whose " + "total length = %d", tot_len); + data->inbuf = wpabuf_alloc(tot_len); + if (data->inbuf == NULL) { + wpa_printf(MSG_INFO, "Out of memory to buffer " + "fragments!"); + return NULL; + } + pos += sizeof(u16); + len -= sizeof(u16); + } + /* + * buffer and ACK the fragment + */ + if (EAP_PWD_GET_MORE_BIT(lm_exch)) { + 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->in_frag_pos = 0; + return NULL; + } + wpabuf_put_data(data->inbuf, pos, len); + + 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) { + wpabuf_put_data(data->inbuf, pos, len); + wpa_printf(MSG_DEBUG, "EAP-pwd: Last fragment, %d bytes", + (int) len); + data->in_frag_pos += 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->in_frag_pos = 0; + } + + if (data->outbuf == NULL) + return NULL; /* generic failure */ + + /* + * we have output! Do we need to fragment it? + */ + 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; + } + + 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; + int ret; + + EVP_add_digest(EVP_sha256()); + 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->get_emsk = eap_pwd_get_emsk; + + ret = eap_peer_method_register(eap); + if (ret) + eap_peer_method_free(eap); + return ret; +} |