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-rw-r--r--src/eap_server/eap_server_pwd.c823
1 files changed, 823 insertions, 0 deletions
diff --git a/src/eap_server/eap_server_pwd.c b/src/eap_server/eap_server_pwd.c
new file mode 100644
index 0000000..d1b89ea
--- /dev/null
+++ b/src/eap_server/eap_server_pwd.c
@@ -0,0 +1,823 @@
+/*
+ * hostapd / EAP-pwd (RFC 5931) server
+ * Copyright (c) 2010, Dan Harkins <dharkins@lounge.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the BSD license.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License version 2 as published by the Free Software
+ * Foundation.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "eap_server/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;
+ u32 token;
+ u16 group_num;
+ EAP_PWD_group *grp;
+
+ BIGNUM *k;
+ BIGNUM *private_value;
+ BIGNUM *peer_scalar;
+ BIGNUM *my_scalar;
+ EC_POINT *my_element;
+ EC_POINT *peer_element;
+
+ u8 msk[EAP_MSK_LEN];
+ u8 emsk[EAP_EMSK_LEN];
+};
+
+static BN_CTX *bnctx;
+
+
+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";
+ }
+}
+
+
+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;
+
+ if (sm->user == NULL || sm->user->password == NULL ||
+ sm->user->password_len == 0) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): Password is not "
+ "configured");
+ return NULL;
+ }
+
+ data = os_zalloc(sizeof(*data));
+ if (data == NULL)
+ return NULL;
+
+ data->group_num = sm->pwd_group;
+ wpa_printf(MSG_DEBUG, "EAP-pwd: Selected group number %d",
+ data->group_num);
+ data->state = PWD_ID_Req;
+
+ data->id_server = (u8 *) os_strdup("server");
+ if (data->id_server)
+ data->id_server_len = os_strlen((char *)data->id_server);
+
+ data->password = os_malloc(sm->user->password_len);
+ if (data->password == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PWD: Mmemory allocation password "
+ "fail");
+ return NULL;
+ }
+ data->password_len = sm->user->password_len;
+ os_memcpy(data->password, sm->user->password, data->password_len);
+
+ bnctx = BN_CTX_new();
+ if (bnctx == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PWD: bn context allocation fail");
+ return NULL;
+ }
+
+ return data;
+}
+
+
+static void eap_pwd_reset(struct eap_sm *sm, void *priv)
+{
+ struct eap_pwd_data *data = priv;
+
+ BN_free(data->private_value);
+ BN_free(data->peer_scalar);
+ BN_free(data->my_scalar);
+ BN_free(data->k);
+ BN_CTX_free(bnctx);
+ EC_POINT_free(data->my_element);
+ EC_POINT_free(data->peer_element);
+ os_free(data->id_peer);
+ os_free(data->id_server);
+ os_free(data->grp);
+ os_free(data);
+}
+
+
+static struct wpabuf *
+eap_pwd_build_id_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
+{
+ struct wpabuf *req;
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd: ID/Request");
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
+ sizeof(struct eap_pwd_hdr) +
+ sizeof(struct eap_pwd_id) + data->id_server_len,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ eap_pwd_state(data, FAILURE);
+ return NULL;
+ }
+
+ /* an lfsr is good enough to generate unpredictable tokens */
+ data->token = os_random();
+ wpabuf_put_u8(req, EAP_PWD_OPCODE_ID_EXCH);
+ wpabuf_put_be16(req, data->group_num);
+ wpabuf_put_u8(req, EAP_PWD_DEFAULT_RAND_FUNC);
+ wpabuf_put_u8(req, EAP_PWD_DEFAULT_PRF);
+ wpabuf_put_data(req, &data->token, sizeof(data->token));
+ wpabuf_put_u8(req, EAP_PWD_PREP_NONE);
+ wpabuf_put_data(req, data->id_server, data->id_server_len);
+
+ return req;
+}
+
+
+static struct wpabuf *
+eap_pwd_build_commit_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
+{
+ struct wpabuf *req = NULL;
+ BIGNUM *mask = NULL, *x = NULL, *y = NULL;
+ u8 *scalar = NULL, *element = NULL;
+ u16 offset;
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd: Commit/Request");
+
+ if (((data->private_value = BN_new()) == NULL) ||
+ ((data->my_element = EC_POINT_new(data->grp->group)) == NULL) ||
+ ((data->my_scalar = BN_new()) == NULL) ||
+ ((mask = BN_new()) == NULL)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): scalar allocation "
+ "fail");
+ 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, bnctx);
+
+ if (!EC_POINT_mul(data->grp->group, data->my_element, NULL,
+ data->grp->pwe, mask, bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): element allocation "
+ "fail");
+ eap_pwd_state(data, FAILURE);
+ goto fin;
+ }
+
+ if (!EC_POINT_invert(data->grp->group, data->my_element, bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): element inversion "
+ "fail");
+ goto fin;
+ }
+ BN_free(mask);
+
+ if (((x = BN_new()) == NULL) ||
+ ((y = BN_new()) == NULL)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): point allocation "
+ "fail");
+ goto fin;
+ }
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
+ data->my_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): 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 (server): 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);
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
+ sizeof(struct eap_pwd_hdr) +
+ (2 * BN_num_bytes(data->grp->prime)) +
+ BN_num_bytes(data->grp->order),
+ EAP_CODE_REQUEST, id);
+ if (req == NULL)
+ goto fin;
+ wpabuf_put_u8(req, EAP_PWD_OPCODE_COMMIT_EXCH);
+
+ /* We send the element as (x,y) followed by the scalar */
+ wpabuf_put_data(req, element, (2 * BN_num_bytes(data->grp->prime)));
+ wpabuf_put_data(req, scalar, BN_num_bytes(data->grp->order));
+
+fin:
+ os_free(scalar);
+ os_free(element);
+ BN_free(x);
+ BN_free(y);
+ if (req == NULL)
+ eap_pwd_state(data, FAILURE);
+
+ return req;
+}
+
+
+static struct wpabuf *
+eap_pwd_build_confirm_req(struct eap_sm *sm, struct eap_pwd_data *data, u8 id)
+{
+ struct wpabuf *req = NULL;
+ BIGNUM *x = NULL, *y = NULL;
+ HMAC_CTX ctx;
+ u8 conf[SHA256_DIGEST_LENGTH], *cruft = NULL, *ptr;
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd: Confirm/Request");
+
+ /* 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): debug allocation "
+ "fail");
+ goto fin;
+ }
+
+ /*
+ * commit is H(k | server_element | server_scalar | peer_element |
+ * peer_scalar | ciphersuite)
+ */
+ H_Init(&ctx);
+
+ /*
+ * 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.
+ *
+ * First is k
+ */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->k, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* server element: x, y */
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
+ data->my_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
+ "assignment fail");
+ goto fin;
+ }
+
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(x, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(y, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* server scalar */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->my_scalar, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->order));
+
+ /* peer element: x, y */
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
+ data->peer_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
+ "assignment fail");
+ goto fin;
+ }
+
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(x, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(y, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* peer scalar */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->peer_scalar, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->order));
+
+ /* ciphersuite */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ ptr = cruft;
+ os_memcpy(ptr, &data->group_num, sizeof(u16));
+ ptr += sizeof(u16);
+ *ptr = EAP_PWD_DEFAULT_RAND_FUNC;
+ ptr += sizeof(u8);
+ *ptr = EAP_PWD_DEFAULT_PRF;
+ ptr += sizeof(u8);
+ H_Update(&ctx, cruft, ptr-cruft);
+
+ /* all done with the random function */
+ H_Final(&ctx, conf);
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_PWD,
+ sizeof(struct eap_pwd_hdr) + SHA256_DIGEST_LENGTH,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL)
+ goto fin;
+
+ wpabuf_put_u8(req, EAP_PWD_OPCODE_CONFIRM_EXCH);
+ wpabuf_put_data(req, conf, SHA256_DIGEST_LENGTH);
+
+fin:
+ os_free(cruft);
+ BN_free(x);
+ BN_free(y);
+ if (req == NULL)
+ eap_pwd_state(data, FAILURE);
+
+ return req;
+}
+
+
+static struct wpabuf *
+eap_pwd_build_req(struct eap_sm *sm, void *priv, u8 id)
+{
+ struct eap_pwd_data *data = priv;
+
+ switch (data->state) {
+ case PWD_ID_Req:
+ return eap_pwd_build_id_req(sm, data, id);
+ case PWD_Commit_Req:
+ return eap_pwd_build_commit_req(sm, data, id);
+ case PWD_Confirm_Req:
+ return eap_pwd_build_confirm_req(sm, data, id);
+ default:
+ wpa_printf(MSG_INFO, "EAP-pwd: Unknown state %d in build_req",
+ data->state);
+ break;
+ }
+
+ return NULL;
+}
+
+
+static Boolean eap_pwd_check(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_pwd_data *data = priv;
+ const u8 *pos;
+ size_t len;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len);
+ if (pos == NULL || len < 1) {
+ wpa_printf(MSG_INFO, "EAP-pwd: Invalid frame");
+ return TRUE;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd: Received frame: opcode=%d", *pos);
+
+ if (data->state == PWD_ID_Req && *pos == EAP_PWD_OPCODE_ID_EXCH)
+ return FALSE;
+
+ if (data->state == PWD_Commit_Req &&
+ *pos == EAP_PWD_OPCODE_COMMIT_EXCH)
+ return FALSE;
+
+ if (data->state == PWD_Confirm_Req &&
+ *pos == EAP_PWD_OPCODE_CONFIRM_EXCH)
+ return FALSE;
+
+ wpa_printf(MSG_INFO, "EAP-pwd: Unexpected opcode=%d in state=%d",
+ *pos, data->state);
+
+ return TRUE;
+}
+
+
+static void eap_pwd_process_id_resp(struct eap_sm *sm,
+ struct eap_pwd_data *data,
+ const u8 *payload, size_t payload_len)
+{
+ struct eap_pwd_id *id;
+
+ if (payload_len < sizeof(struct eap_pwd_id)) {
+ wpa_printf(MSG_INFO, "EAP-pwd: Invalid ID response");
+ return;
+ }
+
+ id = (struct eap_pwd_id *) payload;
+ if ((data->group_num != be_to_host16(id->group_num)) ||
+ (id->random_function != EAP_PWD_DEFAULT_RAND_FUNC) ||
+ (os_memcmp(id->token, (u8 *)&data->token, sizeof(data->token))) ||
+ (id->prf != EAP_PWD_DEFAULT_PRF)) {
+ wpa_printf(MSG_INFO, "EAP-pwd: peer changed parameters");
+ eap_pwd_state(data, FAILURE);
+ return;
+ }
+ data->id_peer = os_malloc(payload_len - sizeof(struct eap_pwd_id));
+ if (data->id_peer == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PWD: memory allocation id fail");
+ return;
+ }
+ data->id_peer_len = payload_len - sizeof(struct eap_pwd_id);
+ os_memcpy(data->id_peer, id->identity, data->id_peer_len);
+ wpa_hexdump_ascii(MSG_DEBUG, "EAP-PWD (server): peer sent id of",
+ data->id_peer, data->id_peer_len);
+
+ if ((data->grp = os_malloc(sizeof(EAP_PWD_group))) == NULL) {
+ wpa_printf(MSG_INFO, "EAP-PWD: failed to allocate memory for "
+ "group");
+ return;
+ }
+ 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,
+ (u8 *) &data->token)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): unable to compute "
+ "PWE");
+ return;
+ }
+ wpa_printf(MSG_DEBUG, "EAP-PWD (server): computed %d bit PWE...",
+ BN_num_bits(data->grp->prime));
+
+ eap_pwd_state(data, PWD_Commit_Req);
+}
+
+
+static void
+eap_pwd_process_commit_resp(struct eap_sm *sm, struct eap_pwd_data *data,
+ const u8 *payload, size_t payload_len)
+{
+ u8 *ptr;
+ BIGNUM *x = NULL, *y = NULL, *cofactor = NULL;
+ EC_POINT *K = NULL, *point = NULL;
+ int res = 0;
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd: Received commit response");
+
+ if (((data->peer_scalar = BN_new()) == NULL) ||
+ ((data->k = BN_new()) == NULL) ||
+ ((cofactor = BN_new()) == NULL) ||
+ ((x = BN_new()) == NULL) ||
+ ((y = BN_new()) == NULL) ||
+ ((point = EC_POINT_new(data->grp->group)) == NULL) ||
+ ((K = EC_POINT_new(data->grp->group)) == NULL) ||
+ ((data->peer_element = EC_POINT_new(data->grp->group)) == NULL)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): peer data allocation "
+ "fail");
+ goto fin;
+ }
+
+ if (!EC_GROUP_get_cofactor(data->grp->group, cofactor, NULL)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): unable to get "
+ "cofactor for curve");
+ 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->peer_scalar);
+ if (!EC_POINT_set_affine_coordinates_GFp(data->grp->group,
+ data->peer_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): setting peer element "
+ "fail");
+ goto fin;
+ }
+
+ /* check to ensure peer'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->peer_element, cofactor, NULL)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): cannot "
+ "multiply peer element by order");
+ goto fin;
+ }
+ if (EC_POINT_is_at_infinity(data->grp->group, point)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): peer 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->peer_scalar, bnctx)) ||
+ (!EC_POINT_add(data->grp->group, K, K, data->peer_element,
+ bnctx)) ||
+ (!EC_POINT_mul(data->grp->group, K, NULL, K, data->private_value,
+ bnctx))) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): 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 (server): cannot "
+ "multiply shared key point by order!\n");
+ 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 (server): shared key point is "
+ "at infinity");
+ goto fin;
+ }
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group, K, data->k,
+ NULL, bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): unable to extract "
+ "shared secret from secret point");
+ goto fin;
+ }
+ res = 1;
+
+fin:
+ EC_POINT_free(K);
+ EC_POINT_free(point);
+ BN_free(cofactor);
+ BN_free(x);
+ BN_free(y);
+
+ if (res)
+ eap_pwd_state(data, PWD_Confirm_Req);
+ else
+ eap_pwd_state(data, FAILURE);
+}
+
+
+static void
+eap_pwd_process_confirm_resp(struct eap_sm *sm, struct eap_pwd_data *data,
+ const u8 *payload, size_t payload_len)
+{
+ BIGNUM *x = NULL, *y = NULL;
+ HMAC_CTX ctx;
+ u32 cs;
+ u8 conf[SHA256_DIGEST_LENGTH], *cruft = NULL, *ptr;
+
+ /* build up the ciphersuite: group | random_function | prf */
+ ptr = (u8 *) &cs;
+ os_memcpy(ptr, &data->group_num, 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 (peer): allocation fail");
+ goto fin;
+ }
+
+ /*
+ * commit is H(k | peer_element | peer_scalar | server_element |
+ * server_scalar | ciphersuite)
+ */
+ H_Init(&ctx);
+
+ /* k */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->k, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* peer element: x, y */
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
+ data->peer_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
+ "assignment fail");
+ goto fin;
+ }
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(x, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(y, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* peer scalar */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->peer_scalar, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->order));
+
+ /* server element: x, y */
+ if (!EC_POINT_get_affine_coordinates_GFp(data->grp->group,
+ data->my_element, x, y,
+ bnctx)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): confirm point "
+ "assignment fail");
+ goto fin;
+ }
+
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(x, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(y, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->prime));
+
+ /* server scalar */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ BN_bn2bin(data->my_scalar, cruft);
+ H_Update(&ctx, cruft, BN_num_bytes(data->grp->order));
+
+ /* ciphersuite */
+ os_memset(cruft, 0, BN_num_bytes(data->grp->prime));
+ H_Update(&ctx, (u8 *)&cs, sizeof(u32));
+
+ /* all done */
+ H_Final(&ctx, conf);
+
+ ptr = (u8 *) payload;
+ if (os_memcmp(conf, ptr, SHA256_DIGEST_LENGTH)) {
+ wpa_printf(MSG_INFO, "EAP-PWD (server): confirm did not "
+ "verify");
+ goto fin;
+ }
+
+ wpa_printf(MSG_DEBUG, "EAP-pwd (server): confirm verified");
+ if (compute_keys(data->grp, bnctx, data->k, data->my_element,
+ data->peer_element, data->my_scalar,
+ data->peer_scalar, &cs, data->msk, data->emsk) < 0)
+ eap_pwd_state(data, FAILURE);
+ else
+ eap_pwd_state(data, SUCCESS);
+
+fin:
+ os_free(cruft);
+ BN_free(x);
+ BN_free(y);
+}
+
+
+static void eap_pwd_process(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_pwd_data *data = priv;
+ const u8 *pos;
+ size_t len;
+ u8 exch;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_PWD, respData, &len);
+ if ((pos == NULL) || (len < 1)) {
+ wpa_printf(MSG_INFO, "Bad EAP header! pos %s and len = %d",
+ (pos == NULL) ? "is NULL" : "is not NULL",
+ (int) len);
+ return;
+ }
+
+ exch = *pos & 0x3f;
+ switch (exch) {
+ case EAP_PWD_OPCODE_ID_EXCH:
+ eap_pwd_process_id_resp(sm, data, pos + 1, len - 1);
+ break;
+ case EAP_PWD_OPCODE_COMMIT_EXCH:
+ eap_pwd_process_commit_resp(sm, data, pos + 1, len - 1);
+ break;
+ case EAP_PWD_OPCODE_CONFIRM_EXCH:
+ eap_pwd_process_confirm_resp(sm, data, pos + 1, len - 1);
+ break;
+ }
+}
+
+
+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_emsk(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_EMSK_LEN);
+ if (key == NULL)
+ return NULL;
+
+ os_memcpy(key, data->emsk, EAP_EMSK_LEN);
+ *len = EAP_EMSK_LEN;
+
+ return key;
+}
+
+
+static Boolean eap_pwd_is_success(struct eap_sm *sm, void *priv)
+{
+ struct eap_pwd_data *data = priv;
+ return data->state == SUCCESS;
+}
+
+
+static Boolean eap_pwd_is_done(struct eap_sm *sm, void *priv)
+{
+ struct eap_pwd_data *data = priv;
+ return (data->state == SUCCESS) || (data->state == FAILURE);
+}
+
+
+int eap_server_pwd_register(void)
+{
+ struct eap_method *eap;
+ int ret;
+ struct timeval tp;
+ struct timezone tz;
+ u32 sr;
+
+ EVP_add_digest(EVP_sha256());
+
+ sr = 0xdeaddada;
+ (void) gettimeofday(&tp, &tz);
+ sr ^= (tp.tv_sec ^ tp.tv_usec);
+ srandom(sr);
+
+ eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
+ EAP_VENDOR_IETF, EAP_TYPE_PWD,
+ "PWD");
+ if (eap == NULL)
+ return -1;
+
+ eap->init = eap_pwd_init;
+ eap->reset = eap_pwd_reset;
+ eap->buildReq = eap_pwd_build_req;
+ eap->check = eap_pwd_check;
+ eap->process = eap_pwd_process;
+ eap->isDone = eap_pwd_is_done;
+ eap->getKey = eap_pwd_getkey;
+ eap->get_emsk = eap_pwd_get_emsk;
+ eap->isSuccess = eap_pwd_is_success;
+
+ ret = eap_server_method_register(eap);
+ if (ret)
+ eap_server_method_free(eap);
+ return ret;
+}
+