aboutsummaryrefslogtreecommitdiffstats
path: root/src/eap_server/eap_server_mschapv2.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/eap_server/eap_server_mschapv2.c')
-rw-r--r--src/eap_server/eap_server_mschapv2.c574
1 files changed, 574 insertions, 0 deletions
diff --git a/src/eap_server/eap_server_mschapv2.c b/src/eap_server/eap_server_mschapv2.c
new file mode 100644
index 0000000..39d1c6e
--- /dev/null
+++ b/src/eap_server/eap_server_mschapv2.c
@@ -0,0 +1,574 @@
+/*
+ * hostapd / EAP-MSCHAPv2 (draft-kamath-pppext-eap-mschapv2-00.txt) server
+ * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "crypto/ms_funcs.h"
+#include "eap_i.h"
+
+
+struct eap_mschapv2_hdr {
+ u8 op_code; /* MSCHAPV2_OP_* */
+ u8 mschapv2_id; /* must be changed for challenges, but not for
+ * success/failure */
+ u8 ms_length[2]; /* Note: misaligned; length - 5 */
+ /* followed by data */
+} STRUCT_PACKED;
+
+#define MSCHAPV2_OP_CHALLENGE 1
+#define MSCHAPV2_OP_RESPONSE 2
+#define MSCHAPV2_OP_SUCCESS 3
+#define MSCHAPV2_OP_FAILURE 4
+#define MSCHAPV2_OP_CHANGE_PASSWORD 7
+
+#define MSCHAPV2_RESP_LEN 49
+
+#define ERROR_RESTRICTED_LOGON_HOURS 646
+#define ERROR_ACCT_DISABLED 647
+#define ERROR_PASSWD_EXPIRED 648
+#define ERROR_NO_DIALIN_PERMISSION 649
+#define ERROR_AUTHENTICATION_FAILURE 691
+#define ERROR_CHANGING_PASSWORD 709
+
+#define PASSWD_CHANGE_CHAL_LEN 16
+#define MSCHAPV2_KEY_LEN 16
+
+
+#define CHALLENGE_LEN 16
+
+struct eap_mschapv2_data {
+ u8 auth_challenge[CHALLENGE_LEN];
+ int auth_challenge_from_tls;
+ u8 *peer_challenge;
+ u8 auth_response[20];
+ enum { CHALLENGE, SUCCESS_REQ, FAILURE_REQ, SUCCESS, FAILURE } state;
+ u8 resp_mschapv2_id;
+ u8 master_key[16];
+ int master_key_valid;
+};
+
+
+static void * eap_mschapv2_init(struct eap_sm *sm)
+{
+ struct eap_mschapv2_data *data;
+
+ data = os_zalloc(sizeof(*data));
+ if (data == NULL)
+ return NULL;
+ data->state = CHALLENGE;
+
+ if (sm->auth_challenge) {
+ os_memcpy(data->auth_challenge, sm->auth_challenge,
+ CHALLENGE_LEN);
+ data->auth_challenge_from_tls = 1;
+ }
+
+ if (sm->peer_challenge) {
+ data->peer_challenge = os_malloc(CHALLENGE_LEN);
+ if (data->peer_challenge == NULL) {
+ os_free(data);
+ return NULL;
+ }
+ os_memcpy(data->peer_challenge, sm->peer_challenge,
+ CHALLENGE_LEN);
+ }
+
+ return data;
+}
+
+
+static void eap_mschapv2_reset(struct eap_sm *sm, void *priv)
+{
+ struct eap_mschapv2_data *data = priv;
+ if (data == NULL)
+ return;
+
+ os_free(data->peer_challenge);
+ os_free(data);
+}
+
+
+static struct wpabuf * eap_mschapv2_build_challenge(
+ struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
+{
+ struct wpabuf *req;
+ struct eap_mschapv2_hdr *ms;
+ char *name = "hostapd"; /* TODO: make this configurable */
+ size_t ms_len;
+
+ if (!data->auth_challenge_from_tls &&
+ os_get_random(data->auth_challenge, CHALLENGE_LEN)) {
+ wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to get random "
+ "data");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ ms_len = sizeof(*ms) + 1 + CHALLENGE_LEN + os_strlen(name);
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
+ " for request");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ ms = wpabuf_put(req, sizeof(*ms));
+ ms->op_code = MSCHAPV2_OP_CHALLENGE;
+ ms->mschapv2_id = id;
+ WPA_PUT_BE16(ms->ms_length, ms_len);
+
+ wpabuf_put_u8(req, CHALLENGE_LEN);
+ if (!data->auth_challenge_from_tls)
+ wpabuf_put_data(req, data->auth_challenge, CHALLENGE_LEN);
+ else
+ wpabuf_put(req, CHALLENGE_LEN);
+ wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Challenge",
+ data->auth_challenge, CHALLENGE_LEN);
+ wpabuf_put_data(req, name, os_strlen(name));
+
+ return req;
+}
+
+
+static struct wpabuf * eap_mschapv2_build_success_req(
+ struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
+{
+ struct wpabuf *req;
+ struct eap_mschapv2_hdr *ms;
+ u8 *msg;
+ char *message = "OK";
+ size_t ms_len;
+
+ ms_len = sizeof(*ms) + 2 + 2 * sizeof(data->auth_response) + 1 + 2 +
+ os_strlen(message);
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
+ " for request");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ ms = wpabuf_put(req, sizeof(*ms));
+ ms->op_code = MSCHAPV2_OP_SUCCESS;
+ ms->mschapv2_id = data->resp_mschapv2_id;
+ WPA_PUT_BE16(ms->ms_length, ms_len);
+ msg = (u8 *) (ms + 1);
+
+ wpabuf_put_u8(req, 'S');
+ wpabuf_put_u8(req, '=');
+ wpa_snprintf_hex_uppercase(
+ wpabuf_put(req, sizeof(data->auth_response) * 2),
+ sizeof(data->auth_response) * 2 + 1,
+ data->auth_response, sizeof(data->auth_response));
+ wpabuf_put_u8(req, ' ');
+ wpabuf_put_u8(req, 'M');
+ wpabuf_put_u8(req, '=');
+ wpabuf_put_data(req, message, os_strlen(message));
+
+ wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Success Request Message",
+ msg, ms_len - sizeof(*ms));
+
+ return req;
+}
+
+
+static struct wpabuf * eap_mschapv2_build_failure_req(
+ struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id)
+{
+ struct wpabuf *req;
+ struct eap_mschapv2_hdr *ms;
+ char *message = "E=691 R=0 C=00000000000000000000000000000000 V=3 "
+ "M=FAILED";
+ size_t ms_len;
+
+ ms_len = sizeof(*ms) + os_strlen(message);
+ req = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL) {
+ wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to allocate memory"
+ " for request");
+ data->state = FAILURE;
+ return NULL;
+ }
+
+ ms = wpabuf_put(req, sizeof(*ms));
+ ms->op_code = MSCHAPV2_OP_FAILURE;
+ ms->mschapv2_id = data->resp_mschapv2_id;
+ WPA_PUT_BE16(ms->ms_length, ms_len);
+
+ wpabuf_put_data(req, message, os_strlen(message));
+
+ wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Failure Request Message",
+ (u8 *) message, os_strlen(message));
+
+ return req;
+}
+
+
+static struct wpabuf * eap_mschapv2_buildReq(struct eap_sm *sm, void *priv,
+ u8 id)
+{
+ struct eap_mschapv2_data *data = priv;
+
+ switch (data->state) {
+ case CHALLENGE:
+ return eap_mschapv2_build_challenge(sm, data, id);
+ case SUCCESS_REQ:
+ return eap_mschapv2_build_success_req(sm, data, id);
+ case FAILURE_REQ:
+ return eap_mschapv2_build_failure_req(sm, data, id);
+ default:
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
+ "buildReq", data->state);
+ break;
+ }
+ return NULL;
+}
+
+
+static Boolean eap_mschapv2_check(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_mschapv2_data *data = priv;
+ struct eap_mschapv2_hdr *resp;
+ const u8 *pos;
+ size_t len;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
+ &len);
+ if (pos == NULL || len < 1) {
+ wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid frame");
+ return TRUE;
+ }
+
+ resp = (struct eap_mschapv2_hdr *) pos;
+ if (data->state == CHALLENGE &&
+ resp->op_code != MSCHAPV2_OP_RESPONSE) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Response - "
+ "ignore op %d", resp->op_code);
+ return TRUE;
+ }
+
+ if (data->state == SUCCESS_REQ &&
+ resp->op_code != MSCHAPV2_OP_SUCCESS &&
+ resp->op_code != MSCHAPV2_OP_FAILURE) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Success or "
+ "Failure - ignore op %d", resp->op_code);
+ return TRUE;
+ }
+
+ if (data->state == FAILURE_REQ &&
+ resp->op_code != MSCHAPV2_OP_FAILURE) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Expected Failure "
+ "- ignore op %d", resp->op_code);
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+
+static void eap_mschapv2_process_response(struct eap_sm *sm,
+ struct eap_mschapv2_data *data,
+ struct wpabuf *respData)
+{
+ struct eap_mschapv2_hdr *resp;
+ const u8 *pos, *end, *peer_challenge, *nt_response, *name;
+ u8 flags;
+ size_t len, name_len, i;
+ u8 expected[24];
+ const u8 *username, *user;
+ size_t username_len, user_len;
+ int res;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
+ &len);
+ if (pos == NULL || len < 1)
+ return; /* Should not happen - frame already validated */
+
+ end = pos + len;
+ resp = (struct eap_mschapv2_hdr *) pos;
+ pos = (u8 *) (resp + 1);
+
+ if (len < sizeof(*resp) + 1 + 49 ||
+ resp->op_code != MSCHAPV2_OP_RESPONSE ||
+ pos[0] != 49) {
+ wpa_hexdump_buf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid response",
+ respData);
+ data->state = FAILURE;
+ return;
+ }
+ data->resp_mschapv2_id = resp->mschapv2_id;
+ pos++;
+ peer_challenge = pos;
+ pos += 16 + 8;
+ nt_response = pos;
+ pos += 24;
+ flags = *pos++;
+ name = pos;
+ name_len = end - name;
+
+ if (data->peer_challenge) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using pre-configured "
+ "Peer-Challenge");
+ peer_challenge = data->peer_challenge;
+ }
+ wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Peer-Challenge",
+ peer_challenge, 16);
+ wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: NT-Response", nt_response, 24);
+ wpa_printf(MSG_MSGDUMP, "EAP-MSCHAPV2: Flags 0x%x", flags);
+ wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: Name", name, name_len);
+
+ /* MSCHAPv2 does not include optional domain name in the
+ * challenge-response calculation, so remove domain prefix
+ * (if present). */
+ username = sm->identity;
+ username_len = sm->identity_len;
+ for (i = 0; i < username_len; i++) {
+ if (username[i] == '\\') {
+ username_len -= i + 1;
+ username += i + 1;
+ break;
+ }
+ }
+
+ user = name;
+ user_len = name_len;
+ for (i = 0; i < user_len; i++) {
+ if (user[i] == '\\') {
+ user_len -= i + 1;
+ user += i + 1;
+ break;
+ }
+ }
+
+ if (username_len != user_len ||
+ os_memcmp(username, user, username_len) != 0) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Mismatch in user names");
+ wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Expected user "
+ "name", username, username_len);
+ wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Received user "
+ "name", user, user_len);
+ data->state = FAILURE;
+ return;
+ }
+
+ wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-MSCHAPV2: User name",
+ username, username_len);
+
+ if (sm->user->password_hash) {
+ res = generate_nt_response_pwhash(data->auth_challenge,
+ peer_challenge,
+ username, username_len,
+ sm->user->password,
+ expected);
+ } else {
+ res = generate_nt_response(data->auth_challenge,
+ peer_challenge,
+ username, username_len,
+ sm->user->password,
+ sm->user->password_len,
+ expected);
+ }
+ if (res) {
+ data->state = FAILURE;
+ return;
+ }
+
+ if (os_memcmp(nt_response, expected, 24) == 0) {
+ const u8 *pw_hash;
+ u8 pw_hash_buf[16], pw_hash_hash[16];
+
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Correct NT-Response");
+ data->state = SUCCESS_REQ;
+
+ /* Authenticator response is not really needed yet, but
+ * calculate it here so that peer_challenge and username need
+ * not be saved. */
+ if (sm->user->password_hash) {
+ pw_hash = sm->user->password;
+ } else {
+ nt_password_hash(sm->user->password,
+ sm->user->password_len,
+ pw_hash_buf);
+ pw_hash = pw_hash_buf;
+ }
+ generate_authenticator_response_pwhash(
+ pw_hash, peer_challenge, data->auth_challenge,
+ username, username_len, nt_response,
+ data->auth_response);
+
+ hash_nt_password_hash(pw_hash, pw_hash_hash);
+ get_master_key(pw_hash_hash, nt_response, data->master_key);
+ data->master_key_valid = 1;
+ wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived Master Key",
+ data->master_key, MSCHAPV2_KEY_LEN);
+ } else {
+ wpa_hexdump(MSG_MSGDUMP, "EAP-MSCHAPV2: Expected NT-Response",
+ expected, 24);
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Invalid NT-Response");
+ data->state = FAILURE_REQ;
+ }
+}
+
+
+static void eap_mschapv2_process_success_resp(struct eap_sm *sm,
+ struct eap_mschapv2_data *data,
+ struct wpabuf *respData)
+{
+ struct eap_mschapv2_hdr *resp;
+ const u8 *pos;
+ size_t len;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
+ &len);
+ if (pos == NULL || len < 1)
+ return; /* Should not happen - frame already validated */
+
+ resp = (struct eap_mschapv2_hdr *) pos;
+
+ if (resp->op_code == MSCHAPV2_OP_SUCCESS) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Success Response"
+ " - authentication completed successfully");
+ data->state = SUCCESS;
+ } else {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Success "
+ "Response - peer rejected authentication");
+ data->state = FAILURE;
+ }
+}
+
+
+static void eap_mschapv2_process_failure_resp(struct eap_sm *sm,
+ struct eap_mschapv2_data *data,
+ struct wpabuf *respData)
+{
+ struct eap_mschapv2_hdr *resp;
+ const u8 *pos;
+ size_t len;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, respData,
+ &len);
+ if (pos == NULL || len < 1)
+ return; /* Should not happen - frame already validated */
+
+ resp = (struct eap_mschapv2_hdr *) pos;
+
+ if (resp->op_code == MSCHAPV2_OP_FAILURE) {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received Failure Response"
+ " - authentication failed");
+ } else {
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Did not receive Failure "
+ "Response - authentication failed");
+ }
+
+ data->state = FAILURE;
+}
+
+
+static void eap_mschapv2_process(struct eap_sm *sm, void *priv,
+ struct wpabuf *respData)
+{
+ struct eap_mschapv2_data *data = priv;
+
+ if (sm->user == NULL || sm->user->password == NULL) {
+ wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured");
+ data->state = FAILURE;
+ return;
+ }
+
+ switch (data->state) {
+ case CHALLENGE:
+ eap_mschapv2_process_response(sm, data, respData);
+ break;
+ case SUCCESS_REQ:
+ eap_mschapv2_process_success_resp(sm, data, respData);
+ break;
+ case FAILURE_REQ:
+ eap_mschapv2_process_failure_resp(sm, data, respData);
+ break;
+ default:
+ wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Unknown state %d in "
+ "process", data->state);
+ break;
+ }
+}
+
+
+static Boolean eap_mschapv2_isDone(struct eap_sm *sm, void *priv)
+{
+ struct eap_mschapv2_data *data = priv;
+ return data->state == SUCCESS || data->state == FAILURE;
+}
+
+
+static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len)
+{
+ struct eap_mschapv2_data *data = priv;
+ u8 *key;
+
+ if (data->state != SUCCESS || !data->master_key_valid)
+ return NULL;
+
+ *len = 2 * MSCHAPV2_KEY_LEN;
+ key = os_malloc(*len);
+ if (key == NULL)
+ return NULL;
+ /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key */
+ get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 0, 1);
+ get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN,
+ MSCHAPV2_KEY_LEN, 1, 1);
+ wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", key, *len);
+
+ return key;
+}
+
+
+static Boolean eap_mschapv2_isSuccess(struct eap_sm *sm, void *priv)
+{
+ struct eap_mschapv2_data *data = priv;
+ return data->state == SUCCESS;
+}
+
+
+int eap_server_mschapv2_register(void)
+{
+ struct eap_method *eap;
+ int ret;
+
+ eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
+ EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2,
+ "MSCHAPV2");
+ if (eap == NULL)
+ return -1;
+
+ eap->init = eap_mschapv2_init;
+ eap->reset = eap_mschapv2_reset;
+ eap->buildReq = eap_mschapv2_buildReq;
+ eap->check = eap_mschapv2_check;
+ eap->process = eap_mschapv2_process;
+ eap->isDone = eap_mschapv2_isDone;
+ eap->getKey = eap_mschapv2_getKey;
+ eap->isSuccess = eap_mschapv2_isSuccess;
+
+ ret = eap_server_method_register(eap);
+ if (ret)
+ eap_server_method_free(eap);
+ return ret;
+}