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mod_auth_radius.c
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/* ====================================================================
* Copyright (c) 1997-2002 The Apache Group. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the Apache Group
* for use in the Apache HTTP server project (http://www.apache.org/)."
*
* 4. The names "Apache Server" and "Apache Group" must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 5. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the Apache Group
* for use in the Apache HTTP server project (http://www.apache.org/)."
*
* THIS SOFTWARE IS PROVIDED BY THE APACHE GROUP ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE APACHE GROUP OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Group and was originally based
* on public domain software written at the National Center for
* Supercomputing Applications, University of Illinois, Urbana-Champaign.
* For more information on the Apache Group and the Apache HTTP server
* project, please see <http://www.apache.org/>.
*/
#include <stdint.h>
#include <netdb.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_log.h"
#include "http_protocol.h"
#include "util_md5.h"
#include "apr_general.h"
#include "apr_tables.h"
#include "apr_strings.h"
#include "ap_release.h"
#include "ap_provider.h"
#include "mod_auth.h"
#include "http_request.h"
#if AP_SERVER_MAJORVERSION_NUMBER >= 2 && AP_SERVER_MINORVERSION_NUMBER >= 4
#define client_ip_get(_r) (_r->useragent_ip)
#else
#define client_ip_get(_r) (_r->connection->remote_ip)
#endif
#define RADLOG_DEBUG(srv, fmt, ...) ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_DEBUG, 0, srv, fmt, ## __VA_ARGS__)
#define RADLOG_WARN(srv, fmt, ...) ap_log_error(APLOG_MARK, APLOG_NOERRNO | APLOG_WARNING, 0, srv, fmt, ## __VA_ARGS__)
#define radcpy(STRING, ATTR) do { \
uint8_t len = ATTR->length; \
if (len >= 2) len-=2; \
memcpy(STRING, ATTR->data, len); \
(STRING)[len] = 0;} while (0)
#define RADIUS_AUTH_UDP_PORT 1812
#define RADIUS_PASSWORD_LEN 16
#define RADIUS_RANDOM_VECTOR_LEN 16
#define RADIUS_DEFAULT_WAIT 5
#define RADIUS_DEFAULT_RETRIES 0
#define RADIUS_DEFAULT_TIMEOUT 60
/* Per-attribute structure */
typedef struct attribute_t {
uint8_t attribute;
uint8_t length;
uint8_t data[1];
} attribute_t;
/* Packet header structure */
typedef struct radius_packet_t {
uint8_t code;
uint8_t id;
uint16_t length;
uint8_t vector[RADIUS_RANDOM_VECTOR_LEN];
attribute_t first;
} radius_packet_t;
#define RADIUS_HEADER_LEN 20
/* RADIUS ID definitions. See RFC 2138 */
#define RADIUS_ACCESS_REQUEST 1
#define RADIUS_ACCESS_ACCEPT 2
#define RADIUS_ACCESS_REJECT 3
#define RADIUS_ACCESS_CHALLENGE 11
/* RADIUS attribute definitions. Also from RFC 2138 */
#define RADIUS_USER_NAME 1
#define RADIUS_PASSWORD 2
#define RADIUS_NAS_IP_ADDRESS 4
#define RADIUS_SERVICE_TYPE 6
#define RADIUS_REPLY_MESSAGE 18
#define RADIUS_STATE 24
#define RADIUS_SESSION_TIMEOUT 27
#define RADIUS_CALLING_STATION_ID 31
#define RADIUS_NAS_IDENTIFIER 32
/* service types : authenticate only for now */
#define RADIUS_AUTHENTICATE_ONLY 8
/* How large the packets may be */
#define RADIUS_PACKET_RECV_SIZE 1024
#define RADIUS_PACKET_SEND_SIZE 1024
#define APACHE_RADIUS_MAGIC_STATE "f36809ad"
#ifndef FALSE
# define FALSE 0
#endif
#ifndef TRUE
# define TRUE !FALSE
#endif
/* Add a cookie to an outgoing request */
static const char *cookie_name = "RADIUS";
#define COOKIE_SIZE 1024
module AP_MODULE_DECLARE_DATA radius_auth_module;
/* per-server configuration structure */
typedef struct radius_server_config_rec_s {
struct in_addr *radius_ip; /* server IP address */
char *secret; /* server shared secret */
int secret_len; /* length of the secret (to save time later) */
int timeout; /* cookie valid time */
int wait; /* wait for RADIUS server responses */
int retries; /* number of retries on timeout */
uint16_t port; /* RADIUS port number */
unsigned long bind_address; /* bind socket to this local address */
struct radius_server_config_rec_s *next; /* fallback server(s) */
} radius_server_config_rec_t;
/* per-server configuration create */
static void *radius_server_config_alloc(apr_pool_t *p, server_rec *s)
{
radius_server_config_rec_t *scr;
scr = (radius_server_config_rec_t *)apr_pcalloc(p, sizeof(radius_server_config_rec_t));
scr->radius_ip = NULL; /* no server yet */
scr->port = 0; /* 0 uses the default value from RADIUS_AUTH_UDP_PORT */
scr->secret = NULL; /* no secret yet */
scr->secret_len = 0;
scr->wait = -1; /* -1 uses the default value from RADIUS_DEFAULT_WAIT */
scr->retries = -1; /* -1 uses the default value from RADIUS_DEFAULT_RETRIES */
scr->timeout = -1; /* -1 uses the default value from RADIUS_DEFAULT_TIMEOUT */
scr->bind_address = INADDR_ANY;
scr->next = NULL;
return scr;
}
/*
* This function gets called to merge two per-server configuration
* records. This is typically done to cope with things like virtual hosts and
* the default server configuration. The routine has the responsibility of
* creating a new record and merging the contents of the other two into it
* appropriately. If the module doesn't declare a merge routine, the more
* specific existing record is used exclusively.
*
* The routine MUST NOT modify any of its arguments!
*
* The return value is a pointer to the created module-specific structure
* containing the merged values.
*/
static void *radius_server_config_merge(apr_pool_t *p,
void *parent_config,
void *newloc_config)
{
radius_server_config_rec_t *merged_config = radius_server_config_alloc(p, NULL);
radius_server_config_rec_t *old_config = (radius_server_config_rec_t *)parent_config;
radius_server_config_rec_t *new_config = (radius_server_config_rec_t *)newloc_config;
void *result = NULL;
result = (new_config->radius_ip == NULL) ? old_config->radius_ip : new_config->radius_ip;
if (result != NULL) {
merged_config->radius_ip = apr_pcalloc(p, sizeof(struct in_addr));
*merged_config->radius_ip = *((struct in_addr *)result); /* make a copy */
}
result = (new_config->secret == NULL) ? old_config->secret : new_config->secret;
if (result != NULL) {
merged_config->secret = apr_pstrdup(p, (char *)result); /* make a copy */
merged_config->secret_len = strlen(merged_config->secret);
}
merged_config->port = (new_config->port == 0)?old_config->port:new_config->port;
merged_config->wait = (new_config->wait == -1)?old_config->wait:new_config->wait;
merged_config->retries = (new_config->retries == -1)?old_config->retries:new_config->retries;
merged_config->timeout = (new_config->timeout == -1)?old_config->timeout:new_config->timeout;
merged_config->bind_address = (new_config->bind_address == INADDR_ANY)?old_config->bind_address:new_config->bind_address;
return (void *)merged_config;
}
/* RADIUS utility functions */
static struct in_addr *ip_addr_get(apr_pool_t *p,
const char *hostname)
{
struct hostent *hp;
if ((hp = gethostbyname(hostname)) != NULL) {
struct in_addr *ipaddr = apr_pcalloc(p, sizeof(struct in_addr));
*ipaddr = *(struct in_addr *)hp->h_addr; /* make a local copy */
return ipaddr;
}
return NULL;
}
/* get a random vector */
static void random_vector_get(uint8_t *vector)
{
struct timeval tv;
struct timezone tz;
static unsigned int session = 1; /* make the random number harder to guess */
apr_md5_ctx_t my_md5;
/*
* Use the time of day with the best resolution the system can
* give us -- often close to microsecond accuracy.
*/
gettimeofday(&tv, &tz);
tv.tv_sec ^= getpid() * session++; /* add some secret information: session */
/* Hash things to get some cryptographically strong pseudo-random numbers */
apr_md5_init(&my_md5);
apr_md5_update(&my_md5, (uint8_t *)&tv, sizeof(tv));
apr_md5_update(&my_md5, (uint8_t *)&tz, sizeof(tz));
apr_md5_final(vector, &my_md5); /* set the final vector */
}
/* Per-dir configuration structure */
typedef struct radius_dir_config_rec {
radius_server_config_rec_t *server;
int active;
/* Are we doing RADIUS in this dir? */
int authoritative;
/* is RADIUS authentication authoritative? */
int timeout;
/* cookie time valid */
char *calling_station_id; /* custom value for specifying hardcoded calling station ID */
int debug_mode; /* Dump all data talked with Radius */
} radius_dir_config_rec_t;
/* Per-dir configuration create */
static void *radius_per_directory_config_alloc(apr_pool_t *p, char *d)
{
radius_dir_config_rec_t *rec;
rec = (radius_dir_config_rec_t *)apr_pcalloc(p, sizeof(radius_dir_config_rec_t));
rec->server = NULL; /* no valid server by default */
rec->active = 1; /* active by default */
rec->authoritative = 1; /* authoritative by default */
rec->timeout = -1; /* let the server config decide timeouts */
rec->calling_station_id = NULL; /* no custom value for calling station ID yet ; use default behavior */
rec->debug_mode = FALSE;
return rec;
}
/*
* This function gets called to merge two per-directory configuration
* records. This is typically done to cope with things like .htaccess files
* or <Location> directives for directories that are beneath one for which a
* configuration record was already created. The routine has the
* responsibility of creating a new record and merging the contents of the
* other two into it appropriately. If the module doesn't declare a merge
* routine, the record for the closest ancestor location (that has one) is
* used exclusively.
*
* The routine MUST NOT modify any of its arguments!
*
* The return value is a pointer to the created module-specific structure
* containing the merged values.
*/
static void *radius_per_directory_config_merge(apr_pool_t *p,
void *parent_config,
void *newloc_config)
{
radius_dir_config_rec_t *merged_config = radius_per_directory_config_alloc(p, NULL);
radius_dir_config_rec_t *old_config = (radius_dir_config_rec_t *)parent_config;
radius_dir_config_rec_t *new_config = (radius_dir_config_rec_t *)newloc_config;
void *result = NULL;
result = (new_config->calling_station_id == NULL) ?
old_config->calling_station_id : new_config->calling_station_id;
if (result != NULL) {
merged_config->calling_station_id = apr_pstrdup(p, (char *)result); /* make a copy */
}
merged_config->active = new_config->active;
merged_config->authoritative = new_config->authoritative;
merged_config->timeout = (new_config->timeout==-1)?old_config->timeout:new_config->timeout;
merged_config->debug_mode = new_config->debug_mode;
return (void *)merged_config;
}
/* AddRadiusAuth: per-server set configuration */
static const char *radius_server_add(cmd_parms *cmd,
void *mconfig,
const char *server,
const char *secret,
const char *wait)
{
radius_server_config_rec_t *scr;
uint16_t port;
char *p;
scr = ap_get_module_config(cmd->server->module_config, &radius_auth_module);
/* Check to see if there's a port in the server name */
if ((p = strchr(server, ':')) != NULL) {
*(p++) = 0; /* hammer a zero in it */
port = atoi(p);
if (port < 1024) {
return "AddRadiusAuth: server port number must be 1024 or greater for security reasons";
}
scr->port = (uint16_t)port;
}
if ((scr->radius_ip = ip_addr_get(cmd->pool, server)) == NULL) {
return "AddRadiusAuth: Failed looking up RADIUS server IP address";
}
scr->secret = apr_pstrdup(cmd->pool, secret);
scr->secret_len = strlen(scr->secret);
if (wait != NULL) {
if ((p = strchr(wait, ':')) != NULL) {
*(p++) = 0; /* null terminate the wait part of the string */
scr->retries = atoi(p);
}
scr->wait = atoi(wait);
} /* else it's already initialized */
scr->bind_address = INADDR_ANY;
return NULL;
}
/*
* AuthRadiusBindAddress: Set the local address to which this client is bound.
*/
static const char *bind_address_set(cmd_parms *cmd,
void *mconfig,
const char *arg)
{
radius_server_config_rec_t *scr;
struct in_addr *a;
scr = ap_get_module_config(cmd->server->module_config, &radius_auth_module);
if ((a = ip_addr_get(cmd->pool, arg)) == NULL) return "AuthRadiusBindAddress: Invalid IP address";
scr->bind_address = a->s_addr;
return NULL;
}
/*
* AddRadiusCookieValid: Set the cookie valid time.
*/
static const char *cookie_set_timeout(cmd_parms *cmd,
void *mconfig,
const char *arg)
{
radius_server_config_rec_t *scr;
scr = ap_get_module_config(cmd->server->module_config, &radius_auth_module);
scr->timeout = atoi(arg);
return NULL;
}
/* Table of which command does what */
static command_rec auth_cmds[] = {
AP_INIT_TAKE23("AddRadiusAuth", radius_server_add,
NULL, RSRC_CONF,
"per-server configuration for RADIUS server name:port, shared secret, and optional timeout:retries"),
AP_INIT_TAKE1("AuthRadiusBindAddress", bind_address_set,
NULL, RSRC_CONF,
"per-server binding local socket to this local IP address. RADIUS requests will be sent *from* this IP address."),
AP_INIT_TAKE1("AddRadiusCookieValid", cookie_set_timeout,
NULL, RSRC_CONF,
"per-server time in minutes for which the returned cookie is valid. After this time, authentication will be requested again. Use '0' for forever."),
AP_INIT_TAKE1("AddRadiusCallingStationID", ap_set_string_slot,
(void *)APR_OFFSETOF(radius_dir_config_rec_t, calling_station_id), OR_AUTHCFG,
"per-directory custom value for the calling station ID attribute. If unset, default is to use the client's remote IP address."),
AP_INIT_FLAG("AuthRadiusAuthoritative", ap_set_flag_slot,
(void *)APR_OFFSETOF(radius_dir_config_rec_t, authoritative), OR_AUTHCFG,
"per-directory access on failed authentication. If set to 'no', then access control is passed along to lower modules on failed authentication."),
AP_INIT_TAKE1("AuthRadiusCookieValid", ap_set_int_slot,
(void *)APR_OFFSETOF(radius_dir_config_rec_t, timeout), OR_AUTHCFG,
"per-directory time in minutes for which the returned cookie is valid. After this time, authentication will be requested again .Use 0 for forever."),
AP_INIT_FLAG("AuthRadiusActive", ap_set_flag_slot,
(void *)APR_OFFSETOF(radius_dir_config_rec_t, active), OR_AUTHCFG,
"per-directory toggle the use of RADIUS authentication."),
AP_INIT_FLAG("AuthRadiusDebug", ap_set_flag_slot,
(void *)APR_OFFSETOF(radius_dir_config_rec_t, debug_mode), OR_AUTHCFG,
"Set to 'on' to enable the debug mode, all data talked will be displayed - defaults to off."),
{ NULL }
};
static uint8_t *xor(uint8_t *p, uint8_t *q, int length)
{
int i;
uint8_t *response = p;
for (i = 0; i < length; i++) *(p++) ^= *(q++);
return response;
}
static int packet_verify(request_rec *r,
radius_packet_t *packet,
uint8_t *vector)
{
apr_md5_ctx_t my_md5;
server_rec *s = r->server;
radius_server_config_rec_t *scr;
uint8_t calculated[RADIUS_RANDOM_VECTOR_LEN];
uint8_t reply[RADIUS_RANDOM_VECTOR_LEN];
scr = (radius_server_config_rec_t *)ap_get_module_config(s->module_config, &radius_auth_module);
/*
* We could dispense with the memcpy, and do MD5's of the packet
* + vector piece by piece. This is easier understand, and probably faster.
*/
memcpy(reply, packet->vector, RADIUS_RANDOM_VECTOR_LEN); /* save the reply */
memcpy(packet->vector, vector, RADIUS_RANDOM_VECTOR_LEN); /* sent vector */
/* MD5(packet header + vector + packet data + secret) */
apr_md5_init(&my_md5);
apr_md5_update(&my_md5, (uint8_t *)packet, ntohs(packet->length));
apr_md5_update(&my_md5, (uint8_t *)scr->secret, scr->secret_len);
apr_md5_final(calculated, &my_md5); /* set the final vector */
/* Did he use the same random vector + shared secret? */
if (memcmp(calculated, reply, RADIUS_RANDOM_VECTOR_LEN) != 0) return -1;
return 0;
}
static void attribute_add(radius_packet_t *packet,
int type,
const uint8_t *data,
int length)
{
attribute_t *p;
p = (attribute_t *)((uint8_t *)packet + packet->length);
p->attribute = type;
p->length = length + 2; /* the total size of the attribute */
packet->length += p->length;
memcpy(p->data, data, length);
}
/* make a cookie based on secret + public information */
static char *cookie_alloc(request_rec *r,
time_t expires,
const char *passwd,
const char *string)
{
char one[COOKIE_SIZE], two[COOKIE_SIZE];
char *cookie;
conn_rec *c = r->connection;
server_rec *s = r->server;
radius_server_config_rec_t *scr;
radius_dir_config_rec_t *rec;
const char *hostname;
cookie = apr_pcalloc(r->pool, COOKIE_SIZE);
scr = (radius_server_config_rec_t *)ap_get_module_config(s->module_config, &radius_auth_module);
rec = (radius_dir_config_rec_t *)ap_get_module_config(r->per_dir_config, &radius_auth_module);
if ((hostname = ap_get_remote_host(c, r->per_dir_config, REMOTE_NAME, NULL)) == NULL)
hostname = "www.example.com";
/*
* Arg! We can't use 'ntohs(c->remote_addr.sin_port)', because I.E.
* ignores keepalives, and opens a new connection on EVERY request!
* This is a BAD security problem! It allows multiple users on the
* same machine to access the data.
*
* A derivative security problem is users authenticating from
* behind a firewall.
* All users appear to be coming from the firewall. A malicious
* agent working in the same company as the authorized user can sniff
* the cookie, and and use it themselves. Since they appear to be
* coming from the same IP address (firewall), they're let in.
* Oh well, at least the connection is traceable to a particular machine.
*/
/*
* Piotr Klaban <[email protected]> says:
*
* > The "squid" proxy set HTTP_X_FORWARDED_FOR variable - the
* > original IP of the client. We can use HTTP_X_FORWARDED_FOR
* > variable besides REMOTE_ADDR.
*
* > If cookie is stolen, then atacker could use the same proxy as
* > the client, to validate the cookie. If we would use
* > HTTP_X_FORWARDED_FOR, then useing the proxy would not be
* > sufficient.
*
* We don't do this, mainly because I haven't gotten around to
* writing the code...
*/
/*
* Make a cookie based on secret + public information.
*
* cookie = MAC(M) = apr_md5(secret, MD5(secret, M))
*
* See Scheier, B, "Applied Cryptography" 2nd Ed., p.458
* Also, RFC 2104. I don't know if the HMAC gives any additional
* benefit here.
*/
apr_snprintf(one, COOKIE_SIZE, "%s%s%s%s%s%08x", scr->secret,
r->user, passwd, client_ip_get(r), hostname, (unsigned)expires);
if (rec->debug_mode) { /* if you're REALLY worried about what's going on */
RADLOG_DEBUG(r->server, " secret = %s", scr->secret);
RADLOG_DEBUG(r->server, " user = %s", r->user);
RADLOG_DEBUG(r->server, " passwd = %s", passwd);
RADLOG_DEBUG(r->server, " remote ip = %s", client_ip_get(r));
RADLOG_DEBUG(r->server, " hostname = %s", hostname);
RADLOG_DEBUG(r->server, " expiry = %08x", (unsigned)expires);
}
/* MD5 the cookie to make it secure, and add more secret information */
apr_snprintf(two, COOKIE_SIZE, "%s%s", scr->secret, ap_md5(r->pool, (uint8_t *)one));
if (string == NULL) {
apr_snprintf(cookie, COOKIE_SIZE, "%s%08x",
ap_md5(r->pool, (uint8_t *)two), (unsigned)expires);
} else {
apr_snprintf(cookie, COOKIE_SIZE, "%s%08x%s",
ap_md5(r->pool, (uint8_t *)two), (unsigned)expires, string);
}
return cookie;
}
static int cookie_validate(request_rec *r,
const char *cookie,
const char *passwd)
{
time_t expires, now;
if (strlen(cookie) < (16 + 4) * 2) return FALSE; /* MD5 is 16 bytes, and expiry date is 4*/
sscanf(&cookie[32], "%8lx", &expires);
now = time(NULL);
if (expires < now) return FALSE; /* valid only for a short window of time */
/* Is the returned cookie identical to one made from our secret? */
if (strcmp(cookie, cookie_alloc(r, expires, passwd, NULL)) == 0) return TRUE;
return FALSE; /* cookie doesn't match: re-validate */
}
static void cookie_add(request_rec *r,
apr_table_t *header,
char *cookie,
time_t expires)
{
char *new_cookie = apr_pcalloc(r->pool, COOKIE_SIZE); /* so it'll stick around */
if (expires != 0) {
char buffer[COOKIE_SIZE];
strftime(buffer, sizeof(buffer), "%a %d-%b-%Y %H:%M:%S %Z",
gmtime(&expires));
apr_snprintf(new_cookie, COOKIE_SIZE, "%s=%s; path=/; expires=%s;",
cookie_name, cookie, buffer);
} else {
apr_snprintf(new_cookie, COOKIE_SIZE,
"%s=%s; path=/; expires=Wed, 01-Oct-97 01:01:01 GMT;",
cookie_name, cookie);
}
apr_table_set(header, "Set-Cookie", new_cookie);
}
/* Spot a cookie in an incoming request */
static char *cookie_from_request(request_rec *r)
{
const char *cookie;
char *value;
if ((cookie = apr_table_get(r->headers_in, "Cookie"))) {
if ((value = strstr(cookie, cookie_name))) {
char *cookiebuf, *cookieend;
RADLOG_DEBUG(r->server, "Found Radius Cookie, now check if it's valid...");
value += strlen(cookie_name); /* skip the name */
/*
* Ensure there's an '=' after the name.
*/
if (*value != '=') {
return NULL;
} else {
value++;
}
cookiebuf = apr_pstrdup(r->pool, value);
cookieend = strchr(cookiebuf, ';');
if (cookieend) *cookieend = '\0'; /* Ignore anything after a ; */
/* Set the cookie in a note, for logging */
return cookiebuf; /* Theres already a cookie, no new one */
}
}
return NULL; /* no cookie was found */
}
/* There's a lot of parameters to this function, but it does a lot of work */
static int radius_authenticate(request_rec *r,
radius_server_config_rec_t *scr,
int sockfd,
int code,
char *recv_buffer,
const char *user,
const char *passwd_in,
const char *state,
uint8_t *vector,
char *errstr)
{
struct sockaddr_in *sin;
struct sockaddr saremote;
socklen_t salen;
int total_length;
fd_set set;
int retries = (scr->retries == -1)?RADIUS_DEFAULT_RETRIES:scr->retries;
struct timeval tv;
int rcode = -1;
struct in_addr *ip_addr;
uint8_t misc[RADIUS_RANDOM_VECTOR_LEN];
int password_len, i;
uint8_t password[128];
apr_md5_ctx_t md5_secret, my_md5;
uint32_t service;
uint8_t send_buffer[RADIUS_PACKET_SEND_SIZE];
radius_packet_t *packet = (radius_packet_t *)send_buffer;
radius_dir_config_rec_t *rec;
rec = (radius_dir_config_rec_t *)ap_get_module_config(r->per_dir_config, &radius_auth_module);
i = strlen(passwd_in);
password_len = (i + 0x0f) & 0xfffffff0; /* round off to 16 */
if (password_len == 0) {
password_len = 16; /* it's at least 15 bytes long */
} else if (password_len > 128) { /* password too long, from RFC2138, p.22 */
RADLOG_DEBUG(r->server, "password given by user %s is too long for RADIUS", user);
return FALSE;
}
memset(password, 0, password_len);
memcpy(password, passwd_in, i); /* don't use strcpy! */
/* generate a random authentication vector */
random_vector_get(vector);
/* Fill in the packet header */
memset(send_buffer, 0, sizeof(send_buffer));
packet->code = code;
packet->id = vector[0]; /* make a random request id */
packet->length = RADIUS_HEADER_LEN;
memcpy(packet->vector, vector, RADIUS_RANDOM_VECTOR_LEN);
/* Fill in the user name attribute */
attribute_add(packet, RADIUS_USER_NAME, (uint8_t *)user, strlen(user));
/* encrypt the password */
/* password : e[0] = p[0] ^ MD5(secret + vector) */
apr_md5_init(&md5_secret);
apr_md5_update(&md5_secret, scr->secret, scr->secret_len);
my_md5 = md5_secret; /* so we won't re-do the hash later */
apr_md5_update(&my_md5, vector, RADIUS_RANDOM_VECTOR_LEN);
apr_md5_final(misc, &my_md5); /* set the final vector */
xor(password, misc, RADIUS_PASSWORD_LEN);
/* For each step through, e[i] = p[i] ^ MD5(secret + e[i-1]) */
for (i = 1; i < (password_len >> 4); i++) {
my_md5 = md5_secret; /* grab old value of the hash */
apr_md5_update(&my_md5, &password[(i - 1) * RADIUS_PASSWORD_LEN], RADIUS_PASSWORD_LEN);
apr_md5_final(misc, &my_md5); /* set the final vector */
xor(&password[i * RADIUS_PASSWORD_LEN], misc, RADIUS_PASSWORD_LEN);
}
attribute_add(packet, RADIUS_PASSWORD, password, password_len);
/* Tell the RADIUS server that we only want to authenticate */
service = htonl(RADIUS_AUTHENTICATE_ONLY);
attribute_add(packet, RADIUS_SERVICE_TYPE, (uint8_t *)&service,
sizeof(service));
/* Tell the RADIUS server which virtual server we're coming from */
attribute_add(packet, RADIUS_NAS_IDENTIFIER, (uint8_t *)r->server->server_hostname,
strlen(r->server->server_hostname));
/* Tell the RADIUS server which IP address we're coming from */
if (scr->radius_ip->s_addr == htonl(0x7f000001)) {
ip_addr = scr->radius_ip; /* go to localhost through localhost */
} else {
ip_addr = ip_addr_get(r->pool, r->connection->base_server->server_hostname);
if (ip_addr == NULL) {
RADLOG_DEBUG(r->server, "cannot look up server hostname: %s",
r->connection->base_server->server_hostname);
return FALSE;
}
}
attribute_add(packet, RADIUS_NAS_IP_ADDRESS, (uint8_t *)&ip_addr->s_addr,
sizeof(ip_addr->s_addr));
/* add calling station ID (if custom value not specified, add client IP address) */
if (rec->calling_station_id == NULL) {
attribute_add(packet, RADIUS_CALLING_STATION_ID, (uint8_t *)client_ip_get(r),
strlen(client_ip_get(r)));
} else {
attribute_add(packet, RADIUS_CALLING_STATION_ID, (uint8_t *)rec->calling_station_id,
strlen((char *)rec->calling_station_id));
}
/* add state, if requested */
if (state != NULL) {
attribute_add(packet, RADIUS_STATE, (uint8_t *)state, strlen(state));
}
/* Now that we're done building the packet, we can send it */
total_length = packet->length;
packet->length = htons(packet->length);
sin = (struct sockaddr_in *)&saremote;
memset((char *)sin, '\0', sizeof(saremote));
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = scr->radius_ip->s_addr;
sin->sin_port = htons((scr->port == -1)?RADIUS_AUTH_UDP_PORT:scr->port);
RADLOG_DEBUG(r->server, "Sending packet on %s:%i",
inet_ntoa(*scr->radius_ip), (scr->port == -1)?RADIUS_AUTH_UDP_PORT:scr->port);
while (retries >= 0) {
if (sendto(sockfd, (char *)packet, total_length, 0,
&saremote, sizeof(struct sockaddr_in)) < 0) {
RADLOG_DEBUG(r->server, "Error sending RADIUS packet for user %s: %s", user, strerror(errno));
return FALSE;
}
wait_again:
/* Wait for the response, and verify it. */
salen = sizeof(saremote);
tv.tv_sec = (scr->wait == -1)?RADIUS_DEFAULT_WAIT:scr->wait; /* wait for the specified time */
tv.tv_usec = 0;
FD_ZERO(&set); /* clear out the set */
FD_SET(sockfd, &set); /* wait only for the RADIUS UDP socket */
rcode = select(sockfd + 1, &set, NULL, NULL, &tv);
if ((rcode < 0) && (errno == EINTR)) {
goto wait_again; /* signal, ignore it */
}
if (rcode == 0) { /* done the select, with no data ready */
retries--;
} else {
break; /* exit from the 'while retries' loop */
}
} /* loop over the retries */
/*
* Error. Die.
*/
if (rcode < 0) {
RADLOG_DEBUG(r->server, "Error waiting for RADIUS response: %s", strerror(errno));
return FALSE;
}
/*
* Time out.
*/
if (rcode == 0) {
RADLOG_DEBUG(r->server, "RADIUS server %s failed to respond within %d seconds after each of %d retries",
inet_ntoa(*scr->radius_ip), (scr->wait == -1)?RADIUS_DEFAULT_WAIT:scr->wait, (scr->retries == -1)?RADIUS_DEFAULT_RETRIES:scr->retries);
return FALSE;
}
if ((total_length = recvfrom(sockfd, (char *)recv_buffer,
RADIUS_PACKET_RECV_SIZE, 0, &saremote, &salen)) < 0) {
RADLOG_DEBUG(r->server, "Error reading RADIUS packet: %s", strerror(errno));
return FALSE;
}
if (total_length < RADIUS_HEADER_LEN) {
apr_snprintf(errstr, MAX_STRING_LEN, "Packet is too small");
return FALSE;
}
packet = (radius_packet_t *)recv_buffer; /* we have a new packet */
if ((ntohs(packet->length) > total_length) ||
(ntohs(packet->length) > RADIUS_PACKET_RECV_SIZE)) {
RADLOG_DEBUG(r->server, "RADIUS packet corrupted");
return FALSE;
}
/* Check if we've got everything OK. We should also check packet->id...*/
if (packet_verify(r, packet, vector)) {
RADLOG_DEBUG(r->server, "RADIUS packet fails verification");
return FALSE;
}
return TRUE;
}
/* Find a particular attribute. All we really care about is STATE */
static attribute_t *attribute_find_by_num(radius_packet_t *packet, uint8_t type)
{
attribute_t *attr = &packet->first;
int len = ntohs(packet->length) - RADIUS_HEADER_LEN;
if (!len) return NULL;
while (attr->attribute != type) {
if (attr->length < 2) return NULL;
if ((len -= attr->length) <= 0) return NULL; /* not found */
attr = (attribute_t *)((char *)attr + attr->length);
}
return attr;
}
/* authentication module utility functions */
static int password_check(request_rec *r,
radius_server_config_rec_t *scr,
const char *user,
const char *passwd_in,
const char *state,
char *message,
char *errstr)
{
struct sockaddr_in *sin;
struct sockaddr salocal;
int sockfd;
uint16_t local_port;
uint8_t vector[RADIUS_RANDOM_VECTOR_LEN];
uint8_t recv_buffer[RADIUS_PACKET_RECV_SIZE];
radius_packet_t *packet;
int rcode;
/* connect to a port */
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
RADLOG_DEBUG(r->server, "error opening RADIUS socket for user %s: %s", user, strerror(errno));
return FALSE;
}
sin = (struct sockaddr_in *)&salocal;
memset((char *)sin, '\0', sizeof(salocal));
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = scr->bind_address;
local_port = 1025;
do {
local_port++;
sin->sin_port = htons((uint16_t)local_port);
} while ((bind(sockfd, &salocal, sizeof(struct sockaddr_in)) < 0) && (local_port < 64000));
if (local_port >= 64000) {
close(sockfd);
RADLOG_DEBUG(r->server, "cannot bind to RADIUS socket for user %s", user);
return FALSE;
}
rcode = radius_authenticate(r, scr, sockfd,
RADIUS_ACCESS_REQUEST, (char *)recv_buffer, user, passwd_in, state, vector, errstr);
close(sockfd); /* we're done with it */
if (rcode == FALSE) return FALSE; /* error out */
packet = (radius_packet_t *)recv_buffer;
switch (packet->code) {
case RADIUS_ACCESS_ACCEPT: {
attribute_t *a_timeout;
int i;
a_timeout = attribute_find_by_num(packet, RADIUS_SESSION_TIMEOUT);
if (a_timeout) {
memcpy(&i, a_timeout->data, 4);
i = ntohl(i);
}
*message = 0; /* no message */
return TRUE; /* he likes you! */
}
case RADIUS_ACCESS_REJECT:
RADLOG_DEBUG(r->server, "RADIUS authentication failed for user %s", user);
break;
case RADIUS_ACCESS_CHALLENGE: {
attribute_t *a_state, *a_reply;
time_t expires = time(NULL) + 120; /* state expires in two minutes */
char server_state[256];
char *p;
uint8_t *q;
if (((a_state = attribute_find_by_num(packet, RADIUS_STATE)) == NULL) ||
((a_reply = attribute_find_by_num(packet, RADIUS_REPLY_MESSAGE)) == NULL)) {
RADLOG_DEBUG(r->server, "RADIUS access-challenge received with State or Reply-Message missing");
break;
}
if ((a_state->length <= 2) || (a_reply->length <= 2)) {
apr_snprintf(errstr, MAX_STRING_LEN,
"RADIUS access-challenge received with invalid State or Reply-Message");
break;
}
/* Copy magic state message to the state */
strcpy(server_state, APACHE_RADIUS_MAGIC_STATE);
/*
* Sanitize state to ASCII
*/
for (q = a_state->data; q < (a_state->data + a_state->length); q++) {
if (*q > 0x7f) *q -= 0x80;
if (*q < 'A') *q += 'A';
}
radcpy(server_state + sizeof(APACHE_RADIUS_MAGIC_STATE) - 1, a_state);
/* Copy the Reply-Message back to the caller : do CR/LF smashing */
radcpy(message, a_reply);
p = message; /* strip any control characters */
while (*p) {
if (*p < ' ')
*p = ' ';
p++;
}
/* set the magic cookie */
cookie_add(r, r->err_headers_out, cookie_alloc(r, expires, "", server_state), expires);
/* log the challenge, as it IS an error returned to the user */
RADLOG_DEBUG(r->server, "RADIUS server requested challenge for user %s", user);
break;
}
default: /* don't know what else to do */