| /* |
| * EAP peer method: EAP-MSCHAPV2 (draft-kamath-pppext-eap-mschapv2-00.txt) |
| * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi> |
| * |
| * This software may be distributed under the terms of the BSD license. |
| * See README for more details. |
| * |
| * This file implements EAP peer part of EAP-MSCHAPV2 method (EAP type 26). |
| * draft-kamath-pppext-eap-mschapv2-00.txt defines the Microsoft EAP CHAP |
| * Extensions Protocol, Version 2, for mutual authentication and key |
| * derivation. This encapsulates MS-CHAP-v2 protocol which is defined in |
| * RFC 2759. Use of EAP-MSCHAPV2 derived keys with MPPE cipher is described in |
| * RFC 3079. |
| */ |
| |
| #include "includes.h" |
| |
| #include "common.h" |
| #include "crypto/ms_funcs.h" |
| #include "crypto/random.h" |
| #include "common/wpa_ctrl.h" |
| #include "mschapv2.h" |
| #include "eap_i.h" |
| #include "eap_config.h" |
| |
| |
| #ifdef _MSC_VER |
| #pragma pack(push, 1) |
| #endif /* _MSC_VER */ |
| |
| struct eap_mschapv2_hdr { |
| u8 op_code; /* MSCHAPV2_OP_* */ |
| u8 mschapv2_id; /* usually same as EAP identifier; must be changed |
| * for challenges, but not for success/failure */ |
| u8 ms_length[2]; /* Note: misaligned; length - 5 */ |
| /* followed by data */ |
| } STRUCT_PACKED; |
| |
| /* Response Data field */ |
| struct ms_response { |
| u8 peer_challenge[MSCHAPV2_CHAL_LEN]; |
| u8 reserved[8]; |
| u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN]; |
| u8 flags; |
| } STRUCT_PACKED; |
| |
| /* Change-Password Data field */ |
| struct ms_change_password { |
| u8 encr_password[516]; |
| u8 encr_hash[16]; |
| u8 peer_challenge[MSCHAPV2_CHAL_LEN]; |
| u8 reserved[8]; |
| u8 nt_response[MSCHAPV2_NT_RESPONSE_LEN]; |
| u8 flags[2]; |
| } STRUCT_PACKED; |
| |
| #ifdef _MSC_VER |
| #pragma pack(pop) |
| #endif /* _MSC_VER */ |
| |
| #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 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 |
| |
| |
| struct eap_mschapv2_data { |
| u8 auth_response[MSCHAPV2_AUTH_RESPONSE_LEN]; |
| int auth_response_valid; |
| |
| int prev_error; |
| u8 passwd_change_challenge[PASSWD_CHANGE_CHAL_LEN]; |
| int passwd_change_challenge_valid; |
| int passwd_change_version; |
| |
| /* Optional challenge values generated in EAP-FAST Phase 1 negotiation |
| */ |
| u8 *peer_challenge; |
| u8 *auth_challenge; |
| |
| int phase2; |
| u8 master_key[MSCHAPV2_MASTER_KEY_LEN]; |
| int master_key_valid; |
| int success; |
| |
| struct wpabuf *prev_challenge; |
| }; |
| |
| |
| static void eap_mschapv2_deinit(struct eap_sm *sm, void *priv); |
| |
| |
| static void * eap_mschapv2_init(struct eap_sm *sm) |
| { |
| struct eap_mschapv2_data *data; |
| data = os_zalloc(sizeof(*data)); |
| if (data == NULL) |
| return NULL; |
| |
| if (sm->peer_challenge) { |
| data->peer_challenge = os_malloc(MSCHAPV2_CHAL_LEN); |
| if (data->peer_challenge == NULL) { |
| eap_mschapv2_deinit(sm, data); |
| return NULL; |
| } |
| os_memcpy(data->peer_challenge, sm->peer_challenge, |
| MSCHAPV2_CHAL_LEN); |
| } |
| |
| if (sm->auth_challenge) { |
| data->auth_challenge = os_malloc(MSCHAPV2_CHAL_LEN); |
| if (data->auth_challenge == NULL) { |
| eap_mschapv2_deinit(sm, data); |
| return NULL; |
| } |
| os_memcpy(data->auth_challenge, sm->auth_challenge, |
| MSCHAPV2_CHAL_LEN); |
| } |
| |
| data->phase2 = sm->init_phase2; |
| |
| return data; |
| } |
| |
| |
| static void eap_mschapv2_deinit(struct eap_sm *sm, void *priv) |
| { |
| struct eap_mschapv2_data *data = priv; |
| os_free(data->peer_challenge); |
| os_free(data->auth_challenge); |
| wpabuf_free(data->prev_challenge); |
| os_free(data); |
| } |
| |
| |
| static struct wpabuf * eap_mschapv2_challenge_reply( |
| struct eap_sm *sm, struct eap_mschapv2_data *data, u8 id, |
| u8 mschapv2_id, const u8 *auth_challenge) |
| { |
| struct wpabuf *resp; |
| struct eap_mschapv2_hdr *ms; |
| u8 *peer_challenge; |
| int ms_len; |
| struct ms_response *r; |
| size_t identity_len, password_len; |
| const u8 *identity, *password; |
| int pwhash; |
| |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Generating Challenge Response"); |
| |
| identity = eap_get_config_identity(sm, &identity_len); |
| password = eap_get_config_password2(sm, &password_len, &pwhash); |
| if (identity == NULL || password == NULL) |
| return NULL; |
| |
| ms_len = sizeof(*ms) + 1 + sizeof(*r) + identity_len; |
| resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len, |
| EAP_CODE_RESPONSE, id); |
| if (resp == NULL) |
| return NULL; |
| |
| ms = wpabuf_put(resp, sizeof(*ms)); |
| ms->op_code = MSCHAPV2_OP_RESPONSE; |
| ms->mschapv2_id = mschapv2_id; |
| if (data->prev_error) { |
| /* |
| * TODO: this does not seem to be enough when processing two |
| * or more failure messages. IAS did not increment mschapv2_id |
| * in its own packets, but it seemed to expect the peer to |
| * increment this for all packets(?). |
| */ |
| ms->mschapv2_id++; |
| } |
| WPA_PUT_BE16(ms->ms_length, ms_len); |
| |
| wpabuf_put_u8(resp, sizeof(*r)); /* Value-Size */ |
| |
| /* Response */ |
| r = wpabuf_put(resp, sizeof(*r)); |
| peer_challenge = r->peer_challenge; |
| if (data->peer_challenge) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge generated " |
| "in Phase 1"); |
| peer_challenge = data->peer_challenge; |
| os_memset(r->peer_challenge, 0, MSCHAPV2_CHAL_LEN); |
| } else if (random_get_bytes(peer_challenge, MSCHAPV2_CHAL_LEN)) { |
| wpabuf_free(resp); |
| return NULL; |
| } |
| os_memset(r->reserved, 0, 8); |
| if (data->auth_challenge) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge generated " |
| "in Phase 1"); |
| auth_challenge = data->auth_challenge; |
| } |
| if (mschapv2_derive_response(identity, identity_len, password, |
| password_len, pwhash, auth_challenge, |
| peer_challenge, r->nt_response, |
| data->auth_response, data->master_key)) { |
| wpa_printf(MSG_ERROR, "EAP-MSCHAPV2: Failed to derive " |
| "response"); |
| wpabuf_free(resp); |
| return NULL; |
| } |
| data->auth_response_valid = 1; |
| data->master_key_valid = 1; |
| |
| r->flags = 0; /* reserved, must be zero */ |
| |
| wpabuf_put_data(resp, identity, identity_len); |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d " |
| "(response)", id, ms->mschapv2_id); |
| return resp; |
| } |
| |
| |
| /** |
| * eap_mschapv2_process - Process an EAP-MSCHAPv2 challenge message |
| * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init() |
| * @data: Pointer to private EAP method data from eap_mschapv2_init() |
| * @ret: Return values from EAP request validation and processing |
| * @req: Pointer to EAP-MSCHAPv2 header from the request |
| * @req_len: Length of the EAP-MSCHAPv2 data |
| * @id: EAP identifier used in the request |
| * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if |
| * no reply available |
| */ |
| static struct wpabuf * eap_mschapv2_challenge( |
| struct eap_sm *sm, struct eap_mschapv2_data *data, |
| struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req, |
| size_t req_len, u8 id) |
| { |
| size_t len, challenge_len; |
| const u8 *pos, *challenge; |
| |
| if (eap_get_config_identity(sm, &len) == NULL || |
| eap_get_config_password(sm, &len) == NULL) |
| return NULL; |
| |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received challenge"); |
| if (req_len < sizeof(*req) + 1) { |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge data " |
| "(len %lu)", (unsigned long) req_len); |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| pos = (const u8 *) (req + 1); |
| challenge_len = *pos++; |
| len = req_len - sizeof(*req) - 1; |
| if (challenge_len != MSCHAPV2_CHAL_LEN) { |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid challenge length " |
| "%lu", (unsigned long) challenge_len); |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| if (len < challenge_len) { |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Too short challenge" |
| " packet: len=%lu challenge_len=%lu", |
| (unsigned long) len, (unsigned long) challenge_len); |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| if (data->passwd_change_challenge_valid) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Using challenge from the " |
| "failure message"); |
| challenge = data->passwd_change_challenge; |
| } else |
| challenge = pos; |
| pos += challenge_len; |
| len -= challenge_len; |
| wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Authentication Servername", |
| pos, len); |
| |
| ret->ignore = FALSE; |
| ret->methodState = METHOD_MAY_CONT; |
| ret->decision = DECISION_FAIL; |
| ret->allowNotifications = TRUE; |
| |
| return eap_mschapv2_challenge_reply(sm, data, id, req->mschapv2_id, |
| challenge); |
| } |
| |
| |
| static void eap_mschapv2_password_changed(struct eap_sm *sm, |
| struct eap_mschapv2_data *data) |
| { |
| struct eap_peer_config *config = eap_get_config(sm); |
| if (config && config->new_password) { |
| wpa_msg(sm->msg_ctx, MSG_INFO, |
| WPA_EVENT_PASSWORD_CHANGED |
| "EAP-MSCHAPV2: Password changed successfully"); |
| data->prev_error = 0; |
| os_free(config->password); |
| if (config->flags & EAP_CONFIG_FLAGS_EXT_PASSWORD) { |
| /* TODO: update external storage */ |
| } else if (config->flags & EAP_CONFIG_FLAGS_PASSWORD_NTHASH) { |
| config->password = os_malloc(16); |
| config->password_len = 16; |
| if (config->password) { |
| nt_password_hash(config->new_password, |
| config->new_password_len, |
| config->password); |
| } |
| os_free(config->new_password); |
| } else { |
| config->password = config->new_password; |
| config->password_len = config->new_password_len; |
| } |
| config->new_password = NULL; |
| config->new_password_len = 0; |
| } |
| } |
| |
| |
| /** |
| * eap_mschapv2_process - Process an EAP-MSCHAPv2 success message |
| * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init() |
| * @data: Pointer to private EAP method data from eap_mschapv2_init() |
| * @ret: Return values from EAP request validation and processing |
| * @req: Pointer to EAP-MSCHAPv2 header from the request |
| * @req_len: Length of the EAP-MSCHAPv2 data |
| * @id: EAP identifier used in th erequest |
| * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if |
| * no reply available |
| */ |
| static struct wpabuf * eap_mschapv2_success(struct eap_sm *sm, |
| struct eap_mschapv2_data *data, |
| struct eap_method_ret *ret, |
| const struct eap_mschapv2_hdr *req, |
| size_t req_len, u8 id) |
| { |
| struct wpabuf *resp; |
| const u8 *pos; |
| size_t len; |
| |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received success"); |
| len = req_len - sizeof(*req); |
| pos = (const u8 *) (req + 1); |
| if (!data->auth_response_valid || |
| mschapv2_verify_auth_response(data->auth_response, pos, len)) { |
| wpa_printf(MSG_WARNING, "EAP-MSCHAPV2: Invalid authenticator " |
| "response in success request"); |
| ret->methodState = METHOD_DONE; |
| ret->decision = DECISION_FAIL; |
| return NULL; |
| } |
| pos += 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN; |
| len -= 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN; |
| while (len > 0 && *pos == ' ') { |
| pos++; |
| len--; |
| } |
| wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Success message", |
| pos, len); |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Authentication succeeded"); |
| |
| /* Note: Only op_code of the EAP-MSCHAPV2 header is included in success |
| * message. */ |
| resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1, |
| EAP_CODE_RESPONSE, id); |
| if (resp == NULL) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Failed to allocate " |
| "buffer for success response"); |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| wpabuf_put_u8(resp, MSCHAPV2_OP_SUCCESS); /* op_code */ |
| |
| ret->methodState = METHOD_DONE; |
| ret->decision = DECISION_UNCOND_SUCC; |
| ret->allowNotifications = FALSE; |
| data->success = 1; |
| |
| if (data->prev_error == ERROR_PASSWD_EXPIRED) |
| eap_mschapv2_password_changed(sm, data); |
| |
| return resp; |
| } |
| |
| |
| static int eap_mschapv2_failure_txt(struct eap_sm *sm, |
| struct eap_mschapv2_data *data, char *txt) |
| { |
| char *pos, *msg = ""; |
| int retry = 1; |
| struct eap_peer_config *config = eap_get_config(sm); |
| |
| /* For example: |
| * E=691 R=1 C=<32 octets hex challenge> V=3 M=Authentication Failure |
| */ |
| |
| pos = txt; |
| |
| if (pos && os_strncmp(pos, "E=", 2) == 0) { |
| pos += 2; |
| data->prev_error = atoi(pos); |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: error %d", |
| data->prev_error); |
| pos = os_strchr(pos, ' '); |
| if (pos) |
| pos++; |
| } |
| |
| if (pos && os_strncmp(pos, "R=", 2) == 0) { |
| pos += 2; |
| retry = atoi(pos); |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: retry is %sallowed", |
| retry == 1 ? "" : "not "); |
| pos = os_strchr(pos, ' '); |
| if (pos) |
| pos++; |
| } |
| |
| if (pos && os_strncmp(pos, "C=", 2) == 0) { |
| int hex_len; |
| pos += 2; |
| hex_len = os_strchr(pos, ' ') - (char *) pos; |
| if (hex_len == PASSWD_CHANGE_CHAL_LEN * 2) { |
| if (hexstr2bin(pos, data->passwd_change_challenge, |
| PASSWD_CHANGE_CHAL_LEN)) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid " |
| "failure challenge"); |
| } else { |
| wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: failure " |
| "challenge", |
| data->passwd_change_challenge, |
| PASSWD_CHANGE_CHAL_LEN); |
| data->passwd_change_challenge_valid = 1; |
| } |
| } else { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: invalid failure " |
| "challenge len %d", hex_len); |
| } |
| pos = os_strchr(pos, ' '); |
| if (pos) |
| pos++; |
| } else { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: required challenge field " |
| "was not present in failure message"); |
| } |
| |
| if (pos && os_strncmp(pos, "V=", 2) == 0) { |
| pos += 2; |
| data->passwd_change_version = atoi(pos); |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: password changing " |
| "protocol version %d", data->passwd_change_version); |
| pos = os_strchr(pos, ' '); |
| if (pos) |
| pos++; |
| } |
| |
| if (pos && os_strncmp(pos, "M=", 2) == 0) { |
| pos += 2; |
| msg = pos; |
| } |
| wpa_msg(sm->msg_ctx, MSG_WARNING, |
| "EAP-MSCHAPV2: failure message: '%s' (retry %sallowed, error " |
| "%d)", |
| msg, retry == 1 ? "" : "not ", data->prev_error); |
| if (data->prev_error == ERROR_PASSWD_EXPIRED && |
| data->passwd_change_version == 3 && config) { |
| if (config->new_password == NULL) { |
| wpa_msg(sm->msg_ctx, MSG_INFO, |
| "EAP-MSCHAPV2: Password expired - password " |
| "change required"); |
| eap_sm_request_new_password(sm); |
| } |
| } else if (retry == 1 && config) { |
| /* TODO: could prevent the current password from being used |
| * again at least for some period of time */ |
| if (!config->mschapv2_retry) |
| eap_sm_request_identity(sm); |
| eap_sm_request_password(sm); |
| config->mschapv2_retry = 1; |
| } else if (config) { |
| /* TODO: prevent retries using same username/password */ |
| config->mschapv2_retry = 0; |
| } |
| |
| return retry == 1; |
| } |
| |
| |
| static struct wpabuf * eap_mschapv2_change_password( |
| struct eap_sm *sm, struct eap_mschapv2_data *data, |
| struct eap_method_ret *ret, const struct eap_mschapv2_hdr *req, u8 id) |
| { |
| struct wpabuf *resp; |
| int ms_len; |
| const u8 *username, *password, *new_password; |
| size_t username_len, password_len, new_password_len; |
| struct eap_mschapv2_hdr *ms; |
| struct ms_change_password *cp; |
| u8 password_hash[16], password_hash_hash[16]; |
| int pwhash; |
| |
| username = eap_get_config_identity(sm, &username_len); |
| password = eap_get_config_password2(sm, &password_len, &pwhash); |
| new_password = eap_get_config_new_password(sm, &new_password_len); |
| if (username == NULL || password == NULL || new_password == NULL) |
| return NULL; |
| |
| username = mschapv2_remove_domain(username, &username_len); |
| |
| ret->ignore = FALSE; |
| ret->methodState = METHOD_MAY_CONT; |
| ret->decision = DECISION_COND_SUCC; |
| ret->allowNotifications = TRUE; |
| |
| ms_len = sizeof(*ms) + sizeof(*cp); |
| resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, ms_len, |
| EAP_CODE_RESPONSE, id); |
| if (resp == NULL) |
| return NULL; |
| |
| ms = wpabuf_put(resp, sizeof(*ms)); |
| ms->op_code = MSCHAPV2_OP_CHANGE_PASSWORD; |
| ms->mschapv2_id = req->mschapv2_id + 1; |
| WPA_PUT_BE16(ms->ms_length, ms_len); |
| cp = wpabuf_put(resp, sizeof(*cp)); |
| |
| /* Encrypted-Password */ |
| if (pwhash) { |
| if (encrypt_pw_block_with_password_hash( |
| new_password, new_password_len, |
| password, cp->encr_password)) |
| goto fail; |
| } else { |
| if (new_password_encrypted_with_old_nt_password_hash( |
| new_password, new_password_len, |
| password, password_len, cp->encr_password)) |
| goto fail; |
| } |
| |
| /* Encrypted-Hash */ |
| if (pwhash) { |
| u8 new_password_hash[16]; |
| nt_password_hash(new_password, new_password_len, |
| new_password_hash); |
| nt_password_hash_encrypted_with_block(password, |
| new_password_hash, |
| cp->encr_hash); |
| } else { |
| old_nt_password_hash_encrypted_with_new_nt_password_hash( |
| new_password, new_password_len, |
| password, password_len, cp->encr_hash); |
| } |
| |
| /* Peer-Challenge */ |
| if (random_get_bytes(cp->peer_challenge, MSCHAPV2_CHAL_LEN)) |
| goto fail; |
| |
| /* Reserved, must be zero */ |
| os_memset(cp->reserved, 0, 8); |
| |
| /* NT-Response */ |
| wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: auth_challenge", |
| data->passwd_change_challenge, PASSWD_CHANGE_CHAL_LEN); |
| wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: peer_challenge", |
| cp->peer_challenge, MSCHAPV2_CHAL_LEN); |
| wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: username", |
| username, username_len); |
| wpa_hexdump_ascii_key(MSG_DEBUG, "EAP-MSCHAPV2: new password", |
| new_password, new_password_len); |
| generate_nt_response(data->passwd_change_challenge, cp->peer_challenge, |
| username, username_len, |
| new_password, new_password_len, |
| cp->nt_response); |
| wpa_hexdump(MSG_DEBUG, "EAP-MSCHAPV2: NT-Response", |
| cp->nt_response, MSCHAPV2_NT_RESPONSE_LEN); |
| |
| /* Authenticator response is not really needed yet, but calculate it |
| * here so that challenges need not be saved. */ |
| generate_authenticator_response(new_password, new_password_len, |
| cp->peer_challenge, |
| data->passwd_change_challenge, |
| username, username_len, |
| cp->nt_response, data->auth_response); |
| data->auth_response_valid = 1; |
| |
| /* Likewise, generate master_key here since we have the needed data |
| * available. */ |
| nt_password_hash(new_password, new_password_len, password_hash); |
| hash_nt_password_hash(password_hash, password_hash_hash); |
| get_master_key(password_hash_hash, cp->nt_response, data->master_key); |
| data->master_key_valid = 1; |
| |
| /* Flags */ |
| os_memset(cp->flags, 0, 2); |
| |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: TX identifier %d mschapv2_id %d " |
| "(change pw)", id, ms->mschapv2_id); |
| |
| return resp; |
| |
| fail: |
| wpabuf_free(resp); |
| return NULL; |
| } |
| |
| |
| /** |
| * eap_mschapv2_process - Process an EAP-MSCHAPv2 failure message |
| * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init() |
| * @data: Pointer to private EAP method data from eap_mschapv2_init() |
| * @ret: Return values from EAP request validation and processing |
| * @req: Pointer to EAP-MSCHAPv2 header from the request |
| * @req_len: Length of the EAP-MSCHAPv2 data |
| * @id: EAP identifier used in th erequest |
| * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if |
| * no reply available |
| */ |
| static struct wpabuf * eap_mschapv2_failure(struct eap_sm *sm, |
| struct eap_mschapv2_data *data, |
| struct eap_method_ret *ret, |
| const struct eap_mschapv2_hdr *req, |
| size_t req_len, u8 id) |
| { |
| struct wpabuf *resp; |
| const u8 *msdata = (const u8 *) (req + 1); |
| char *buf; |
| size_t len = req_len - sizeof(*req); |
| int retry = 0; |
| |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Received failure"); |
| wpa_hexdump_ascii(MSG_DEBUG, "EAP-MSCHAPV2: Failure data", |
| msdata, len); |
| /* |
| * eap_mschapv2_failure_txt() expects a nul terminated string, so we |
| * must allocate a large enough temporary buffer to create that since |
| * the received message does not include nul termination. |
| */ |
| buf = os_malloc(len + 1); |
| if (buf) { |
| os_memcpy(buf, msdata, len); |
| buf[len] = '\0'; |
| retry = eap_mschapv2_failure_txt(sm, data, buf); |
| os_free(buf); |
| } |
| |
| ret->ignore = FALSE; |
| ret->methodState = METHOD_DONE; |
| ret->decision = DECISION_FAIL; |
| ret->allowNotifications = FALSE; |
| |
| if (data->prev_error == ERROR_PASSWD_EXPIRED && |
| data->passwd_change_version == 3) { |
| struct eap_peer_config *config = eap_get_config(sm); |
| if (config && config->new_password) |
| return eap_mschapv2_change_password(sm, data, ret, req, |
| id); |
| if (config && config->pending_req_new_password) |
| return NULL; |
| } else if (retry && data->prev_error == ERROR_AUTHENTICATION_FAILURE) { |
| /* TODO: could try to retry authentication, e.g, after having |
| * changed the username/password. In this case, EAP MS-CHAP-v2 |
| * Failure Response would not be sent here. */ |
| return NULL; |
| } |
| |
| /* Note: Only op_code of the EAP-MSCHAPV2 header is included in failure |
| * message. */ |
| resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, 1, |
| EAP_CODE_RESPONSE, id); |
| if (resp == NULL) |
| return NULL; |
| |
| wpabuf_put_u8(resp, MSCHAPV2_OP_FAILURE); /* op_code */ |
| |
| return resp; |
| } |
| |
| |
| static int eap_mschapv2_check_config(struct eap_sm *sm) |
| { |
| size_t len; |
| |
| if (eap_get_config_identity(sm, &len) == NULL) { |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Identity not configured"); |
| eap_sm_request_identity(sm); |
| return -1; |
| } |
| |
| if (eap_get_config_password(sm, &len) == NULL) { |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Password not configured"); |
| eap_sm_request_password(sm); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| static int eap_mschapv2_check_mslen(struct eap_sm *sm, size_t len, |
| const struct eap_mschapv2_hdr *ms) |
| { |
| size_t ms_len = WPA_GET_BE16(ms->ms_length); |
| |
| if (ms_len == len) |
| return 0; |
| |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Invalid header: len=%lu " |
| "ms_len=%lu", (unsigned long) len, (unsigned long) ms_len); |
| if (sm->workaround) { |
| /* Some authentication servers use invalid ms_len, |
| * ignore it for interoperability. */ |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: workaround, ignore" |
| " invalid ms_len %lu (len %lu)", |
| (unsigned long) ms_len, |
| (unsigned long) len); |
| return 0; |
| } |
| |
| return -1; |
| } |
| |
| |
| static void eap_mschapv2_copy_challenge(struct eap_mschapv2_data *data, |
| const struct wpabuf *reqData) |
| { |
| /* |
| * Store a copy of the challenge message, so that it can be processed |
| * again in case retry is allowed after a possible failure. |
| */ |
| wpabuf_free(data->prev_challenge); |
| data->prev_challenge = wpabuf_dup(reqData); |
| } |
| |
| |
| /** |
| * eap_mschapv2_process - Process an EAP-MSCHAPv2 request |
| * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init() |
| * @priv: Pointer to private EAP method data from eap_mschapv2_init() |
| * @ret: Return values from EAP request validation and processing |
| * @reqData: EAP request to be processed (eapReqData) |
| * Returns: Pointer to allocated EAP response packet (eapRespData) or %NULL if |
| * no reply available |
| */ |
| static struct wpabuf * eap_mschapv2_process(struct eap_sm *sm, void *priv, |
| struct eap_method_ret *ret, |
| const struct wpabuf *reqData) |
| { |
| struct eap_mschapv2_data *data = priv; |
| struct eap_peer_config *config = eap_get_config(sm); |
| const struct eap_mschapv2_hdr *ms; |
| int using_prev_challenge = 0; |
| const u8 *pos; |
| size_t len; |
| u8 id; |
| |
| if (eap_mschapv2_check_config(sm)) { |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| if (config->mschapv2_retry && data->prev_challenge && |
| data->prev_error == ERROR_AUTHENTICATION_FAILURE) { |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: Replacing pending packet " |
| "with the previous challenge"); |
| |
| reqData = data->prev_challenge; |
| using_prev_challenge = 1; |
| config->mschapv2_retry = 0; |
| } |
| |
| pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, reqData, |
| &len); |
| if (pos == NULL || len < sizeof(*ms) + 1) { |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| ms = (const struct eap_mschapv2_hdr *) pos; |
| if (eap_mschapv2_check_mslen(sm, len, ms)) { |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| |
| id = eap_get_id(reqData); |
| wpa_printf(MSG_DEBUG, "EAP-MSCHAPV2: RX identifier %d mschapv2_id %d", |
| id, ms->mschapv2_id); |
| |
| switch (ms->op_code) { |
| case MSCHAPV2_OP_CHALLENGE: |
| if (!using_prev_challenge) |
| eap_mschapv2_copy_challenge(data, reqData); |
| return eap_mschapv2_challenge(sm, data, ret, ms, len, id); |
| case MSCHAPV2_OP_SUCCESS: |
| return eap_mschapv2_success(sm, data, ret, ms, len, id); |
| case MSCHAPV2_OP_FAILURE: |
| return eap_mschapv2_failure(sm, data, ret, ms, len, id); |
| default: |
| wpa_printf(MSG_INFO, "EAP-MSCHAPV2: Unknown op %d - ignored", |
| ms->op_code); |
| ret->ignore = TRUE; |
| return NULL; |
| } |
| } |
| |
| |
| static Boolean eap_mschapv2_isKeyAvailable(struct eap_sm *sm, void *priv) |
| { |
| struct eap_mschapv2_data *data = priv; |
| return data->success && data->master_key_valid; |
| } |
| |
| |
| static u8 * eap_mschapv2_getKey(struct eap_sm *sm, void *priv, size_t *len) |
| { |
| struct eap_mschapv2_data *data = priv; |
| u8 *key; |
| int key_len; |
| |
| if (!data->master_key_valid || !data->success) |
| return NULL; |
| |
| key_len = 2 * MSCHAPV2_KEY_LEN; |
| |
| key = os_malloc(key_len); |
| if (key == NULL) |
| return NULL; |
| |
| /* MSK = server MS-MPPE-Recv-Key | MS-MPPE-Send-Key, i.e., |
| * peer MS-MPPE-Send-Key | MS-MPPE-Recv-Key */ |
| get_asymetric_start_key(data->master_key, key, MSCHAPV2_KEY_LEN, 1, 0); |
| get_asymetric_start_key(data->master_key, key + MSCHAPV2_KEY_LEN, |
| MSCHAPV2_KEY_LEN, 0, 0); |
| |
| wpa_hexdump_key(MSG_DEBUG, "EAP-MSCHAPV2: Derived key", |
| key, key_len); |
| |
| *len = key_len; |
| return key; |
| } |
| |
| |
| /** |
| * eap_peer_mschapv2_register - Register EAP-MSCHAPv2 peer method |
| * Returns: 0 on success, -1 on failure |
| * |
| * This function is used to register EAP-MSCHAPv2 peer method into the EAP |
| * method list. |
| */ |
| int eap_peer_mschapv2_register(void) |
| { |
| struct eap_method *eap; |
| int ret; |
| |
| eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION, |
| EAP_VENDOR_IETF, EAP_TYPE_MSCHAPV2, |
| "MSCHAPV2"); |
| if (eap == NULL) |
| return -1; |
| |
| eap->init = eap_mschapv2_init; |
| eap->deinit = eap_mschapv2_deinit; |
| eap->process = eap_mschapv2_process; |
| eap->isKeyAvailable = eap_mschapv2_isKeyAvailable; |
| eap->getKey = eap_mschapv2_getKey; |
| |
| ret = eap_peer_method_register(eap); |
| if (ret) |
| eap_peer_method_free(eap); |
| return ret; |
| } |