hostap/src/eap_peer/eap_md5.c
Jouni Malinen 305dbc9870 EAP-MD5: Verify that CHAP operation succeeds
The MD5 operation may be disabled in the security policy so chap_md5()
call can fail.

Signed-hostap: Jouni Malinen <j@w1.fi>
2012-08-16 18:49:02 +03:00

120 lines
2.9 KiB
C

/*
* EAP peer method: EAP-MD5 (RFC 3748 and RFC 1994)
* Copyright (c) 2004-2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#include "common.h"
#include "eap_i.h"
#include "eap_common/chap.h"
static void * eap_md5_init(struct eap_sm *sm)
{
/* No need for private data. However, must return non-NULL to indicate
* success. */
return (void *) 1;
}
static void eap_md5_deinit(struct eap_sm *sm, void *priv)
{
}
static struct wpabuf * eap_md5_process(struct eap_sm *sm, void *priv,
struct eap_method_ret *ret,
const struct wpabuf *reqData)
{
struct wpabuf *resp;
const u8 *pos, *challenge, *password;
u8 *rpos, id;
size_t len, challenge_len, password_len;
password = eap_get_config_password(sm, &password_len);
if (password == NULL) {
wpa_printf(MSG_INFO, "EAP-MD5: Password not configured");
eap_sm_request_password(sm);
ret->ignore = TRUE;
return NULL;
}
pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_MD5, reqData, &len);
if (pos == NULL || len == 0) {
wpa_printf(MSG_INFO, "EAP-MD5: Invalid frame (pos=%p len=%lu)",
pos, (unsigned long) len);
ret->ignore = TRUE;
return NULL;
}
/*
* CHAP Challenge:
* Value-Size (1 octet) | Value(Challenge) | Name(optional)
*/
challenge_len = *pos++;
if (challenge_len == 0 || challenge_len > len - 1) {
wpa_printf(MSG_INFO, "EAP-MD5: Invalid challenge "
"(challenge_len=%lu len=%lu)",
(unsigned long) challenge_len, (unsigned long) len);
ret->ignore = TRUE;
return NULL;
}
ret->ignore = FALSE;
challenge = pos;
wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Challenge",
challenge, challenge_len);
wpa_printf(MSG_DEBUG, "EAP-MD5: Generating Challenge Response");
ret->methodState = METHOD_DONE;
ret->decision = DECISION_COND_SUCC;
ret->allowNotifications = TRUE;
resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_MD5, 1 + CHAP_MD5_LEN,
EAP_CODE_RESPONSE, eap_get_id(reqData));
if (resp == NULL)
return NULL;
/*
* CHAP Response:
* Value-Size (1 octet) | Value(Response) | Name(optional)
*/
wpabuf_put_u8(resp, CHAP_MD5_LEN);
id = eap_get_id(resp);
rpos = wpabuf_put(resp, CHAP_MD5_LEN);
if (chap_md5(id, password, password_len, challenge, challenge_len,
rpos)) {
wpa_printf(MSG_INFO, "EAP-MD5: CHAP MD5 operation failed");
ret->ignore = TRUE;
wpabuf_free(resp);
return NULL;
}
wpa_hexdump(MSG_MSGDUMP, "EAP-MD5: Response", rpos, CHAP_MD5_LEN);
return resp;
}
int eap_peer_md5_register(void)
{
struct eap_method *eap;
int ret;
eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
EAP_VENDOR_IETF, EAP_TYPE_MD5, "MD5");
if (eap == NULL)
return -1;
eap->init = eap_md5_init;
eap->deinit = eap_md5_deinit;
eap->process = eap_md5_process;
ret = eap_peer_method_register(eap);
if (ret)
eap_peer_method_free(eap);
return ret;
}