radius.c

linux下的ppp协议簇开源代码； 可以进行linux内核级的pppoe拨号

	u_char *p = cpassword;

	if (response_len != MS_CHAP2_RESPONSE_LEN)
	    return 0;
	*p++ = id;
	/* The idiots use a different field order in RADIUS than PPP */
	memcpy(p, rmd->Flags, sizeof(rmd->Flags));
	p += sizeof(rmd->Flags);
	memcpy(p, rmd->PeerChallenge, sizeof(rmd->PeerChallenge));
	p += sizeof(rmd->PeerChallenge);
	memcpy(p, rmd->Reserved, sizeof(rmd->Reserved));
	p += sizeof(rmd->Reserved);
	memcpy(p, rmd->NTResp, sizeof(rmd->NTResp));

	rc_avpair_add(&send, PW_MS_CHAP_CHALLENGE,
		      challenge, challenge_len, VENDOR_MICROSOFT);
	rc_avpair_add(&send, PW_MS_CHAP2_RESPONSE,
		      cpassword, MS_CHAP2_RESPONSE_LEN + 1, VENDOR_MICROSOFT);
	break;
    }
#endif
    }

    if (*remote_number) {
	rc_avpair_add(&send, PW_CALLING_STATION_ID, remote_number, 0,
		       VENDOR_NONE);
    } else if (ipparam)
	rc_avpair_add(&send, PW_CALLING_STATION_ID, ipparam, 0, VENDOR_NONE);

    /* Add user specified vp's */
    if (rstate.avp)
	rc_avpair_insert(&send, NULL, rc_avpair_copy(rstate.avp));

    /*
     * make authentication with RADIUS server
     */

    if (rstate.authserver) {
	result = rc_auth_using_server(rstate.authserver,
				      rstate.client_port, send,
				      &received, radius_msg, req_info);
    } else {
	result = rc_auth(rstate.client_port, send, &received, radius_msg,
			 req_info);
    }

    if (result == OK_RC) {
	if (!rstate.done_chap_once) {
	    if (radius_setparams(received, radius_msg, req_info, digest,
				 challenge, message, message_space) < 0) {
		error("%s", radius_msg);
		result = ERROR_RC;
	    } else {
		rstate.done_chap_once = 1;
	    }
	}
    }

    rc_avpair_free(received);
    rc_avpair_free (send);
    return (result == OK_RC);
}

/**********************************************************************
* %FUNCTION: make_username_realm
* %ARGUMENTS:
*  user -- the user given to pppd
* %RETURNS:
*  Nothing
* %DESCRIPTION:
*  Copies user into rstate.user.  If it lacks a realm (no "@domain" part),
* then the default realm from the radiusclient config file is added.
***********************************************************************/
static void
make_username_realm(char *user)
{
    char *default_realm;

    if ( user != NULL ) {
	strlcpy(rstate.user, user, sizeof(rstate.user));
    }  else {
	rstate.user[0] = 0;
    }

    default_realm = rc_conf_str("default_realm");

    if (!strchr(rstate.user, '@') &&
	default_realm &&
	(*default_realm != '\0')) {
	strlcat(rstate.user, "@", sizeof(rstate.user));
	strlcat(rstate.user, default_realm, sizeof(rstate.user));
    }
}

/**********************************************************************
* %FUNCTION: radius_setparams
* %ARGUMENTS:
*  vp -- received value-pairs
*  msg -- buffer in which to place error message.  Holds up to BUF_LEN chars
* %RETURNS:
*  >= 0 on success; -1 on failure
* %DESCRIPTION:
*  Parses attributes sent by RADIUS server and sets them in pppd.
***********************************************************************/
static int
radius_setparams(VALUE_PAIR *vp, char *msg, REQUEST_INFO *req_info,
		 struct chap_digest_type *digest, unsigned char *challenge,
		 char *message, int message_space)
{
    u_int32_t remote;
    int ms_chap2_success = 0;
#ifdef MPPE
    int mppe_enc_keys = 0;	/* whether or not these were received */
    int mppe_enc_policy = 0;
    int mppe_enc_types = 0;
#endif

    /* Send RADIUS attributes to anyone else who might be interested */
    if (radius_attributes_hook) {
	(*radius_attributes_hook)(vp);
    }

    /*
     * service type (if not framed then quit),
     * new IP address (RADIUS can define static IP for some users),
     */

    while (vp) {
	if (vp->vendorcode == VENDOR_NONE) {
	    switch (vp->attribute) {
	    case PW_SERVICE_TYPE:
		/* check for service type       */
		/* if not FRAMED then exit      */
		if (vp->lvalue != PW_FRAMED) {
		    slprintf(msg, BUF_LEN, "RADIUS: wrong service type %ld for %s",
			     vp->lvalue, rstate.user);
		    return -1;
		}
		break;

	    case PW_FRAMED_PROTOCOL:
		/* check for framed protocol type       */
		/* if not PPP then also exit            */
		if (vp->lvalue != PW_PPP) {
		    slprintf(msg, BUF_LEN, "RADIUS: wrong framed protocol %ld for %s",
			     vp->lvalue, rstate.user);
		    return -1;
		}
		break;

	    case PW_SESSION_TIMEOUT:
		/* Session timeout */
		maxconnect = vp->lvalue;
		break;
#ifdef MAXOCTETS
	    case PW_SESSION_OCTETS_LIMIT:
		/* Session traffic limit */
		maxoctets = vp->lvalue;
		break;
	    case PW_OCTETS_DIRECTION:
		/* Session traffic limit direction check */
		maxoctets_dir = ( vp->lvalue > 4 ) ? 0 : vp->lvalue ;
		break;
#endif
	    case PW_ACCT_INTERIM_INTERVAL:
		/* Send accounting updates every few seconds */
		rstate.acct_interim_interval = vp->lvalue;
		/* RFC says it MUST NOT be less than 60 seconds */
		/* We use "0" to signify not sending updates */
		if (rstate.acct_interim_interval &&
		    rstate.acct_interim_interval < 60) {
		    rstate.acct_interim_interval = 60;
		}
		break;
	    case PW_FRAMED_IP_ADDRESS:
		/* seting up remote IP addresses */
		remote = vp->lvalue;
		if (remote == 0xffffffff) {
		    /* 0xffffffff means user should be allowed to select one */
		    rstate.any_ip_addr_ok = 1;
		} else if (remote != 0xfffffffe) {
		    /* 0xfffffffe means NAS should select an ip address */
		    remote = htonl(vp->lvalue);
		    if (bad_ip_adrs (remote)) {
			slprintf(msg, BUF_LEN, "RADIUS: bad remote IP address %I for %s",
				 remote, rstate.user);
			return -1;
		    }
		    rstate.choose_ip = 1;
		    rstate.ip_addr = remote;
		}
		break;
	    case PW_CLASS:
		/* Save Class attribute to pass it in accounting request */
		if (vp->lvalue <= MAXCLASSLEN) {
		    rstate.class_len=vp->lvalue;
		    memcpy(rstate.class, vp->strvalue, rstate.class_len);
		} /* else too big for our buffer - ignore it */
		break;
	    }


#ifdef CHAPMS
	} else if (vp->vendorcode == VENDOR_MICROSOFT) {
	    switch (vp->attribute) {
	    case PW_MS_CHAP2_SUCCESS:
		if ((vp->lvalue != 43) || strncmp(vp->strvalue + 1, "S=", 2)) {
		    slprintf(msg,BUF_LEN,"RADIUS: bad MS-CHAP2-Success packet");
		    return -1;
		}
		if (message != NULL)
		    strlcpy(message, vp->strvalue + 1, message_space);
		ms_chap2_success = 1;
		break;

#ifdef MPPE
	    case PW_MS_CHAP_MPPE_KEYS:
		if (radius_setmppekeys(vp, req_info, challenge) < 0) {
		    slprintf(msg, BUF_LEN,
			     "RADIUS: bad MS-CHAP-MPPE-Keys attribute");
		    return -1;
		}
		mppe_enc_keys = 1;
		break;

	    case PW_MS_MPPE_SEND_KEY:
	    case PW_MS_MPPE_RECV_KEY:
		if (radius_setmppekeys2(vp, req_info) < 0) {
		    slprintf(msg, BUF_LEN,
			     "RADIUS: bad MS-MPPE-%s-Key attribute",
			     (vp->attribute == PW_MS_MPPE_SEND_KEY)?
			     "Send": "Recv");
		    return -1;
		}
		mppe_enc_keys = 1;
		break;

	    case PW_MS_MPPE_ENCRYPTION_POLICY:
		mppe_enc_policy = vp->lvalue;	/* save for later */
		break;

	    case PW_MS_MPPE_ENCRYPTION_TYPES:
		mppe_enc_types = vp->lvalue;	/* save for later */
		break;

#endif /* MPPE */
#if 0
	    case PW_MS_PRIMARY_DNS_SERVER:
	    case PW_MS_SECONDARY_DNS_SERVER:
	    case PW_MS_PRIMARY_NBNS_SERVER:
	    case PW_MS_SECONDARY_NBNS_SERVER:
		break;
#endif
	    }
#endif /* CHAPMS */
	}
	vp = vp->next;
    }

    /* Require a valid MS-CHAP2-SUCCESS for MS-CHAPv2 auth */
    if (digest && (digest->code == CHAP_MICROSOFT_V2) && !ms_chap2_success)
	return -1;

#ifdef MPPE
    /*
     * Require both policy and key attributes to indicate a valid key.
     * Note that if the policy value was '0' we don't set the key!
     */
    if (mppe_enc_policy && mppe_enc_keys) {
	mppe_keys_set = 1;
	/* Set/modify allowed encryption types. */
	if (mppe_enc_types)
	    set_mppe_enc_types(mppe_enc_policy, mppe_enc_types);
    }
#endif

    return 0;
}

#ifdef MPPE
/**********************************************************************
* %FUNCTION: radius_setmppekeys
* %ARGUMENTS:
*  vp -- value pair holding MS-CHAP-MPPE-KEYS attribute
*  req_info -- radius request information used for encryption
* %RETURNS:
*  >= 0 on success; -1 on failure
* %DESCRIPTION:
*  Decrypt the "key" provided by the RADIUS server for MPPE encryption.
*  See RFC 2548.
***********************************************************************/
static int
radius_setmppekeys(VALUE_PAIR *vp, REQUEST_INFO *req_info,
		   unsigned char *challenge)
{
    int i;
    MD5_CTX Context;
    u_char  plain[32];
    u_char  buf[16];

    if (vp->lvalue != 32) {
	error("RADIUS: Incorrect attribute length (%d) for MS-CHAP-MPPE-Keys",
	      vp->lvalue);
	return -1;
    }

    memcpy(plain, vp->strvalue, sizeof(plain));

    MD5_Init(&Context);
    MD5_Update(&Context, req_info->secret, strlen(req_info->secret));
    MD5_Update(&Context, req_info->request_vector, AUTH_VECTOR_LEN);
    MD5_Final(buf, &Context);

    for (i = 0; i < 16; i++)
	plain[i] ^= buf[i];

    MD5_Init(&Context);
    MD5_Update(&Context, req_info->secret, strlen(req_info->secret));
    MD5_Update(&Context, vp->strvalue, 16);
    MD5_Final(buf, &Context);

    for(i = 0; i < 16; i++)
	plain[i + 16] ^= buf[i];

    /*
     * Annoying.  The "key" returned is just the NTPasswordHashHash, which
     * the NAS (us) doesn't need; we only need the start key.  So we have
     * to generate the start key, sigh.  NB: We do not support the LM-Key.
     */
    mppe_set_keys(challenge, &plain[8]);

    return 0;    
}

/**********************************************************************
* %FUNCTION: radius_setmppekeys2
* %ARGUMENTS:
*  vp -- value pair holding MS-MPPE-SEND-KEY or MS-MPPE-RECV-KEY attribute
*  req_info -- radius request information used for encryption
* %RETURNS:
*  >= 0 on success; -1 on failure
* %DESCRIPTION:
*  Decrypt the key provided by the RADIUS server for MPPE encryption.
*  See RFC 2548.
***********************************************************************/
static int
radius_setmppekeys2(VALUE_PAIR *vp, REQUEST_INFO *req_info)
{
    int i;
    MD5_CTX Context;
    u_char  *salt = vp->strvalue;
    u_char  *crypt = vp->strvalue + 2;
    u_char  plain[32];
    u_char  buf[MD5_HASH_SIZE];
    char    *type = "Send";

    if (vp->attribute == PW_MS_MPPE_RECV_KEY)
	type = "Recv";

    if (vp->lvalue != 34) {
	error("RADIUS: Incorrect attribute length (%d) for MS-MPPE-%s-Key",
	      vp->lvalue, type);
	return -1;
    }

    if ((salt[0] & 0x80) == 0) {
	error("RADIUS: Illegal salt value for MS-MPPE-%s-Key attribute", type);
	return -1;
    }

    memcpy(plain, crypt, 32);

    MD5_Init(&Context);
    MD5_Update(&Context, req_info->secret, strlen(req_info->secret));
    MD5_Update(&Context, req_info->request_vector, AUTH_VECTOR_LEN);
    MD5_Update(&Context, salt, 2);
    MD5_Final(buf, &Context);

    for (i = 0; i < 16; i++)
	plain[i] ^= buf[i];

    if (plain[0] != sizeof(mppe_send_key) /* 16 */) {
	error("RADIUS: Incorrect key length (%d) for MS-MPPE-%s-Key attribute",
	      (int) plain[0], type);
	return -1;
    }

    MD5_Init(&Context);
    MD5_Update(&Context, req_info->secret, strlen(req_info->secret));
    MD5_Update(&Context, crypt, 16);
    MD5_Final(buf, &Context);

    plain[16] ^= buf[0]; /* only need the first byte */

    if (vp->attribute == PW_MS_MPPE_SEND_KEY)
	memcpy(mppe_send_key, plain + 1, 16);
    else
	memcpy(mppe_recv_key, plain + 1, 16);

    return 0;
}
#endif /* MPPE */

/**********************************************************************
* %FUNCTION: radius_acct_start
* %ARGUMENTS:
*  None
* %RETURNS:
*  Nothing
* %DESCRIPTION:
*  Sends a "start" accounting message to the RADIUS server.
***********************************************************************/
static void
radius_acct_start(void)
{
    UINT4 av_type;
    int result;
    VALUE_PAIR *send = NULL;
    ipcp_options *ho = &ipcp_hisoptions[0];
    u_int32_t hisaddr;

    if (!rstate.initialized) {
	return;
    }

    rstate.start_time = time(NULL);

    strncpy(rstate.session_id, rc_mksid(), sizeof(rstate.session_id));

    rc_avpair_add(&send, PW_ACCT_SESSION_ID,
		   rstate.session_id, 0, VENDOR_NONE);
    rc_avpair_add(&send, PW_USER_NAME,
		   rstate.user, 0, VENDOR_NONE);

    if (rstate.class_len > 0)
	rc_avpair_add(&send, PW_CLASS,