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NetBSD/dist/hostapd/radius.c

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/*
* Host AP (software wireless LAN access point) user space daemon for
* Host AP kernel driver / RADIUS client
* Copyright (c) 2002-2005, Jouni Malinen <jkmaline@cc.hut.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 <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <sys/time.h>
#ifndef CONFIG_NATIVE_WINDOWS
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#endif /* CONFIG_NATIVE_WINDOWS */
#include "common.h"
#include "radius.h"
#include "md5.h"
#include "crypto.h"
struct radius_msg *radius_msg_new(u8 code, u8 identifier)
{
struct radius_msg *msg;
msg = (struct radius_msg *) malloc(sizeof(*msg));
if (msg == NULL)
return NULL;
if (radius_msg_initialize(msg, RADIUS_DEFAULT_MSG_SIZE)) {
free(msg);
return NULL;
}
radius_msg_set_hdr(msg, code, identifier);
return msg;
}
int radius_msg_initialize(struct radius_msg *msg, size_t init_len)
{
if (msg == NULL || init_len < sizeof(struct radius_hdr))
return -1;
memset(msg, 0, sizeof(*msg));
msg->buf = (unsigned char *) malloc(init_len);
if (msg->buf == NULL)
return -1;
memset(msg->buf, 0, init_len);
msg->buf_size = init_len;
msg->hdr = (struct radius_hdr *) msg->buf;
msg->buf_used = sizeof(*msg->hdr);
msg->attrs = (struct radius_attr_hdr **)
malloc(RADIUS_DEFAULT_ATTR_COUNT * sizeof(*msg->attrs));
if (msg->attrs == NULL) {
free(msg->buf);
msg->buf = NULL;
msg->hdr = NULL;
return -1;
}
msg->attr_size = RADIUS_DEFAULT_ATTR_COUNT;
msg->attr_used = 0;
return 0;
}
void radius_msg_set_hdr(struct radius_msg *msg, u8 code, u8 identifier)
{
msg->hdr->code = code;
msg->hdr->identifier = identifier;
}
void radius_msg_free(struct radius_msg *msg)
{
if (msg->buf != NULL) {
free(msg->buf);
msg->buf = NULL;
msg->hdr = NULL;
}
msg->buf_size = msg->buf_used = 0;
if (msg->attrs != NULL) {
free(msg->attrs);
msg->attrs = NULL;
}
msg->attr_size = msg->attr_used = 0;
}
static const char *radius_code_string(u8 code)
{
switch (code) {
case RADIUS_CODE_ACCESS_REQUEST: return "Access-Request";
case RADIUS_CODE_ACCESS_ACCEPT: return "Access-Accept";
case RADIUS_CODE_ACCESS_REJECT: return "Access-Reject";
case RADIUS_CODE_ACCOUNTING_REQUEST: return "Accounting-Request";
case RADIUS_CODE_ACCOUNTING_RESPONSE: return "Accounting-Response";
case RADIUS_CODE_ACCESS_CHALLENGE: return "Access-Challenge";
case RADIUS_CODE_STATUS_SERVER: return "Status-Server";
case RADIUS_CODE_STATUS_CLIENT: return "Status-Client";
case RADIUS_CODE_RESERVED: return "Reserved";
default: return "?Unknown?";
}
}
struct radius_attr_type {
u8 type;
char *name;
enum {
RADIUS_ATTR_UNDIST, RADIUS_ATTR_TEXT, RADIUS_ATTR_IP,
RADIUS_ATTR_HEXDUMP, RADIUS_ATTR_INT32, RADIUS_ATTR_IPV6
} data_type;
};
static struct radius_attr_type radius_attrs[] =
{
{ RADIUS_ATTR_USER_NAME, "User-Name", RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_USER_PASSWORD, "User-Password", RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_NAS_IP_ADDRESS, "NAS-IP-Address", RADIUS_ATTR_IP },
{ RADIUS_ATTR_NAS_PORT, "NAS-Port", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_FRAMED_MTU, "Framed-MTU", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_STATE, "State", RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_CLASS, "Class", RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_VENDOR_SPECIFIC, "Vendor-Specific", RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_SESSION_TIMEOUT, "Session-Timeout", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_IDLE_TIMEOUT, "Idle-Timeout", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_TERMINATION_ACTION, "Termination-Action",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_CALLED_STATION_ID, "Called-Station-Id",
RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_CALLING_STATION_ID, "Calling-Station-Id",
RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_NAS_IDENTIFIER, "NAS-Identifier", RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_ACCT_STATUS_TYPE, "Acct-Status-Type",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_DELAY_TIME, "Acct-Delay-Time", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_INPUT_OCTETS, "Acct-Input-Octets",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_OUTPUT_OCTETS, "Acct-Output-Octets",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_SESSION_ID, "Acct-Session-Id", RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_ACCT_AUTHENTIC, "Acct-Authentic", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_SESSION_TIME, "Acct-Session-Time",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_INPUT_PACKETS, "Acct-Input-Packets",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_OUTPUT_PACKETS, "Acct-Output-Packets",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_TERMINATE_CAUSE, "Acct-Terminate-Cause",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_MULTI_SESSION_ID, "Acct-Multi-Session-Id",
RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_ACCT_LINK_COUNT, "Acct-Link-Count", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_INPUT_GIGAWORDS, "Acct-Input-Gigawords",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_ACCT_OUTPUT_GIGAWORDS, "Acct-Output-Gigawords",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_EVENT_TIMESTAMP, "Event-Timestamp",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_NAS_PORT_TYPE, "NAS-Port-Type", RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_CONNECT_INFO, "Connect-Info", RADIUS_ATTR_TEXT },
{ RADIUS_ATTR_EAP_MESSAGE, "EAP-Message", RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_MESSAGE_AUTHENTICATOR, "Message-Authenticator",
RADIUS_ATTR_UNDIST },
{ RADIUS_ATTR_ACCT_INTERIM_INTERVAL, "Acct-Interim-Interval",
RADIUS_ATTR_INT32 },
{ RADIUS_ATTR_NAS_IPV6_ADDRESS, "NAS-IPv6-Address", RADIUS_ATTR_IPV6 },
};
#define RADIUS_ATTRS (sizeof(radius_attrs) / sizeof(radius_attrs[0]))
static struct radius_attr_type *radius_get_attr_type(u8 type)
{
int i;
for (i = 0; i < RADIUS_ATTRS; i++) {
if (type == radius_attrs[i].type)
return &radius_attrs[i];
}
return NULL;
}
static void radius_msg_dump_attr(struct radius_attr_hdr *hdr)
{
struct radius_attr_type *attr;
int i, len;
unsigned char *pos;
attr = radius_get_attr_type(hdr->type);
printf(" Attribute %d (%s) length=%d\n",
hdr->type, attr ? attr->name : "?Unknown?", hdr->length);
if (attr == NULL)
return;
len = hdr->length - sizeof(struct radius_attr_hdr);
pos = (unsigned char *) (hdr + 1);
switch (attr->data_type) {
case RADIUS_ATTR_TEXT:
printf(" Value: '");
for (i = 0; i < len; i++)
print_char(pos[i]);
printf("'\n");
break;
case RADIUS_ATTR_IP:
if (len == 4) {
struct in_addr *addr = (struct in_addr *) pos;
printf(" Value: %s\n", inet_ntoa(*addr));
} else
printf(" Invalid IP address length %d\n", len);
break;
#ifdef CONFIG_IPV6
case RADIUS_ATTR_IPV6:
if (len == 16) {
char buf[128];
const char *atxt;
struct in6_addr *addr = (struct in6_addr *) pos;
atxt = inet_ntop(AF_INET6, addr, buf, sizeof(buf));
printf(" Value: %s\n", atxt ? atxt : "?");
} else
printf(" Invalid IPv6 address length %d\n", len);
break;
#endif /* CONFIG_IPV6 */
case RADIUS_ATTR_HEXDUMP:
case RADIUS_ATTR_UNDIST:
printf(" Value:");
for (i = 0; i < len; i++)
printf(" %02x", pos[i]);
printf("\n");
break;
case RADIUS_ATTR_INT32:
if (len == 4)
printf(" Value: %u\n", WPA_GET_BE32(pos));
else
printf(" Invalid INT32 length %d\n", len);
break;
default:
break;
}
}
void radius_msg_dump(struct radius_msg *msg)
{
int i;
printf("RADIUS message: code=%d (%s) identifier=%d length=%d\n",
msg->hdr->code, radius_code_string(msg->hdr->code),
msg->hdr->identifier, ntohs(msg->hdr->length));
for (i = 0; i < msg->attr_used; i++) {
radius_msg_dump_attr(msg->attrs[i]);
}
}
int radius_msg_finish(struct radius_msg *msg, u8 *secret, size_t secret_len)
{
if (secret) {
u8 auth[MD5_MAC_LEN];
struct radius_attr_hdr *attr;
memset(auth, 0, MD5_MAC_LEN);
attr = radius_msg_add_attr(msg,
RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
auth, MD5_MAC_LEN);
if (attr == NULL) {
printf("WARNING: Could not add "
"Message-Authenticator\n");
return -1;
}
msg->hdr->length = htons(msg->buf_used);
hmac_md5(secret, secret_len, msg->buf, msg->buf_used,
(u8 *) (attr + 1));
} else
msg->hdr->length = htons(msg->buf_used);
if (msg->buf_used > 0xffff) {
printf("WARNING: too long RADIUS message (%lu)\n",
(unsigned long) msg->buf_used);
return -1;
}
return 0;
}
int radius_msg_finish_srv(struct radius_msg *msg, const u8 *secret,
size_t secret_len, const u8 *req_authenticator)
{
u8 auth[MD5_MAC_LEN];
struct radius_attr_hdr *attr;
const u8 *addr[4];
size_t len[4];
memset(auth, 0, MD5_MAC_LEN);
attr = radius_msg_add_attr(msg, RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
auth, MD5_MAC_LEN);
if (attr == NULL) {
printf("WARNING: Could not add Message-Authenticator\n");
return -1;
}
msg->hdr->length = htons(msg->buf_used);
memcpy(msg->hdr->authenticator, req_authenticator,
sizeof(msg->hdr->authenticator));
hmac_md5(secret, secret_len, msg->buf, msg->buf_used,
(u8 *) (attr + 1));
/* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
addr[0] = (u8 *) msg->hdr;
len[0] = 1 + 1 + 2;
addr[1] = req_authenticator;
len[1] = MD5_MAC_LEN;
addr[2] = (u8 *) (msg->hdr + 1);
len[2] = msg->buf_used - sizeof(*msg->hdr);
addr[3] = secret;
len[3] = secret_len;
md5_vector(4, addr, len, msg->hdr->authenticator);
if (msg->buf_used > 0xffff) {
printf("WARNING: too long RADIUS message (%lu)\n",
(unsigned long) msg->buf_used);
return -1;
}
return 0;
}
void radius_msg_finish_acct(struct radius_msg *msg, u8 *secret,
size_t secret_len)
{
const u8 *addr[2];
size_t len[2];
msg->hdr->length = htons(msg->buf_used);
memset(msg->hdr->authenticator, 0, MD5_MAC_LEN);
addr[0] = msg->buf;
len[0] = msg->buf_used;
addr[1] = secret;
len[1] = secret_len;
md5_vector(2, addr, len, msg->hdr->authenticator);
if (msg->buf_used > 0xffff) {
printf("WARNING: too long RADIUS messages (%lu)\n",
(unsigned long) msg->buf_used);
}
}
static int radius_msg_add_attr_to_array(struct radius_msg *msg,
struct radius_attr_hdr *attr)
{
if (msg->attr_used >= msg->attr_size) {
struct radius_attr_hdr **nattrs;
int nlen = msg->attr_size * 2;
nattrs = (struct radius_attr_hdr **)
realloc(msg->attrs, nlen * sizeof(*msg->attrs));
if (nattrs == NULL)
return -1;
msg->attrs = nattrs;
msg->attr_size = nlen;
}
msg->attrs[msg->attr_used++] = attr;
return 0;
}
struct radius_attr_hdr *radius_msg_add_attr(struct radius_msg *msg, u8 type,
const u8 *data, size_t data_len)
{
size_t buf_needed;
struct radius_attr_hdr *attr;
if (data_len > RADIUS_MAX_ATTR_LEN) {
printf("radius_msg_add_attr: too long attribute (%lu bytes)\n",
(unsigned long) data_len);
return NULL;
}
buf_needed = msg->buf_used + sizeof(*attr) + data_len;
if (msg->buf_size < buf_needed) {
/* allocate more space for message buffer */
unsigned char *nbuf;
int nlen = msg->buf_size;
int diff, i;
while (nlen < buf_needed)
nlen *= 2;
nbuf = (unsigned char *) realloc(msg->buf, nlen);
if (nbuf == NULL)
return NULL;
diff = nbuf - msg->buf;
msg->buf = nbuf;
msg->hdr = (struct radius_hdr *) msg->buf;
/* adjust attr pointers to match with the new buffer */
for (i = 0; i < msg->attr_used; i++)
msg->attrs[i] = (struct radius_attr_hdr *)
(((u8 *) msg->attrs[i]) + diff);
memset(msg->buf + msg->buf_size, 0, nlen - msg->buf_size);
msg->buf_size = nlen;
}
attr = (struct radius_attr_hdr *) (msg->buf + msg->buf_used);
attr->type = type;
attr->length = sizeof(*attr) + data_len;
if (data_len > 0)
memcpy(attr + 1, data, data_len);
msg->buf_used += sizeof(*attr) + data_len;
if (radius_msg_add_attr_to_array(msg, attr))
return NULL;
return attr;
}
struct radius_msg *radius_msg_parse(const u8 *data, size_t len)
{
struct radius_msg *msg;
struct radius_hdr *hdr;
struct radius_attr_hdr *attr;
size_t msg_len;
unsigned char *pos, *end;
if (data == NULL || len < sizeof(*hdr))
return NULL;
hdr = (struct radius_hdr *) data;
msg_len = ntohs(hdr->length);
if (msg_len < sizeof(*hdr) || msg_len > len) {
printf("Invalid RADIUS message length\n");
return NULL;
}
if (msg_len < len) {
printf("Ignored %lu extra bytes after RADIUS message\n",
(unsigned long) len - msg_len);
}
msg = (struct radius_msg *) malloc(sizeof(*msg));
if (msg == NULL)
return NULL;
if (radius_msg_initialize(msg, msg_len)) {
free(msg);
return NULL;
}
memcpy(msg->buf, data, msg_len);
msg->buf_size = msg->buf_used = msg_len;
/* parse attributes */
pos = (unsigned char *) (msg->hdr + 1);
end = msg->buf + msg->buf_used;
while (pos < end) {
if (end - pos < sizeof(*attr))
goto fail;
attr = (struct radius_attr_hdr *) pos;
if (pos + attr->length > end || attr->length < sizeof(*attr))
goto fail;
/* TODO: check that attr->length is suitable for attr->type */
if (radius_msg_add_attr_to_array(msg, attr))
goto fail;
pos += attr->length;
}
return msg;
fail:
radius_msg_free(msg);
free(msg);
return NULL;
}
int radius_msg_add_eap(struct radius_msg *msg, const u8 *data, size_t data_len)
{
const u8 *pos = data;
size_t left = data_len;
while (left > 0) {
int len;
if (left > RADIUS_MAX_ATTR_LEN)
len = RADIUS_MAX_ATTR_LEN;
else
len = left;
if (!radius_msg_add_attr(msg, RADIUS_ATTR_EAP_MESSAGE,
pos, len))
return 0;
pos += len;
left -= len;
}
return 1;
}
u8 *radius_msg_get_eap(struct radius_msg *msg, size_t *eap_len)
{
u8 *eap, *pos;
size_t len;
int i;
if (msg == NULL)
return NULL;
len = 0;
for (i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == RADIUS_ATTR_EAP_MESSAGE)
len += msg->attrs[i]->length -
sizeof(struct radius_attr_hdr);
}
if (len == 0)
return NULL;
eap = malloc(len);
if (eap == NULL)
return NULL;
pos = eap;
for (i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == RADIUS_ATTR_EAP_MESSAGE) {
struct radius_attr_hdr *attr = msg->attrs[i];
int flen = attr->length - sizeof(*attr);
memcpy(pos, attr + 1, flen);
pos += flen;
}
}
if (eap_len)
*eap_len = len;
return eap;
}
int radius_msg_verify_msg_auth(struct radius_msg *msg, const u8 *secret,
size_t secret_len, const u8 *req_auth)
{
u8 auth[MD5_MAC_LEN], orig[MD5_MAC_LEN];
u8 orig_authenticator[16];
struct radius_attr_hdr *attr = NULL;
int i;
for (i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == RADIUS_ATTR_MESSAGE_AUTHENTICATOR) {
if (attr != NULL) {
printf("Multiple Message-Authenticator "
"attributes in RADIUS message\n");
return 1;
}
attr = msg->attrs[i];
}
}
if (attr == NULL) {
printf("No Message-Authenticator attribute found\n");
return 1;
}
memcpy(orig, attr + 1, MD5_MAC_LEN);
memset(attr + 1, 0, MD5_MAC_LEN);
if (req_auth) {
memcpy(orig_authenticator, msg->hdr->authenticator,
sizeof(orig_authenticator));
memcpy(msg->hdr->authenticator, req_auth,
sizeof(msg->hdr->authenticator));
}
hmac_md5(secret, secret_len, msg->buf, msg->buf_used, auth);
memcpy(attr + 1, orig, MD5_MAC_LEN);
if (req_auth) {
memcpy(msg->hdr->authenticator, orig_authenticator,
sizeof(orig_authenticator));
}
if (memcmp(orig, auth, MD5_MAC_LEN) != 0) {
printf("Invalid Message-Authenticator!\n");
return 1;
}
return 0;
}
int radius_msg_verify(struct radius_msg *msg, const u8 *secret,
size_t secret_len, struct radius_msg *sent_msg, int auth)
{
const u8 *addr[4];
size_t len[4];
u8 hash[MD5_MAC_LEN];
if (sent_msg == NULL) {
printf("No matching Access-Request message found\n");
return 1;
}
if (auth &&
radius_msg_verify_msg_auth(msg, secret, secret_len,
sent_msg->hdr->authenticator)) {
return 1;
}
/* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
addr[0] = (u8 *) msg->hdr;
len[0] = 1 + 1 + 2;
addr[1] = sent_msg->hdr->authenticator;
len[1] = MD5_MAC_LEN;
addr[2] = (u8 *) (msg->hdr + 1);
len[2] = msg->buf_used - sizeof(*msg->hdr);
addr[3] = secret;
len[3] = secret_len;
md5_vector(4, addr, len, hash);
if (memcmp(hash, msg->hdr->authenticator, MD5_MAC_LEN) != 0) {
printf("Response Authenticator invalid!\n");
return 1;
}
return 0;
}
int radius_msg_copy_attr(struct radius_msg *dst, struct radius_msg *src,
u8 type)
{
struct radius_attr_hdr *attr = NULL;
int i;
for (i = 0; i < src->attr_used; i++) {
if (src->attrs[i]->type == type) {
attr = src->attrs[i];
break;
}
}
if (attr == NULL)
return 0;
if (!radius_msg_add_attr(dst, type, (u8 *) (attr + 1),
attr->length - sizeof(*attr)))
return -1;
return 1;
}
/* Create Request Authenticator. The value should be unique over the lifetime
* of the shared secret between authenticator and authentication server.
* Use one-way MD5 hash calculated from current timestamp and some data given
* by the caller. */
void radius_msg_make_authenticator(struct radius_msg *msg,
u8 *data, size_t len)
{
struct timeval tv;
long int l;
const u8 *addr[3];
size_t elen[3];
gettimeofday(&tv, NULL);
l = random();
addr[0] = (u8 *) &tv;
elen[0] = sizeof(tv);
addr[1] = data;
elen[1] = len;
addr[2] = (u8 *) &l;
elen[2] = sizeof(l);
md5_vector(3, addr, elen, msg->hdr->authenticator);
}
/* Get Vendor-specific RADIUS Attribute from a parsed RADIUS message.
* Returns the Attribute payload and sets alen to indicate the length of the
* payload if a vendor attribute with subtype is found, otherwise returns NULL.
* The returned payload is allocated with malloc() and caller must free it.
*/
static u8 *radius_msg_get_vendor_attr(struct radius_msg *msg, u32 vendor,
u8 subtype, size_t *alen)
{
u8 *data, *pos;
int i;
size_t len;
if (msg == NULL)
return NULL;
for (i = 0; i < msg->attr_used; i++) {
struct radius_attr_hdr *attr = msg->attrs[i];
int left;
u32 vendor_id;
struct radius_attr_vendor *vhdr;
if (attr->type != RADIUS_ATTR_VENDOR_SPECIFIC)
continue;
left = attr->length - sizeof(*attr);
if (left < 4)
continue;
pos = (u8 *) (attr + 1);
memcpy(&vendor_id, pos, 4);
pos += 4;
left -= 4;
if (ntohl(vendor_id) != vendor)
continue;
while (left >= sizeof(*vhdr)) {
vhdr = (struct radius_attr_vendor *) pos;
if (vhdr->vendor_length > left ||
vhdr->vendor_length < sizeof(*vhdr)) {
left = 0;
break;
}
if (vhdr->vendor_type != subtype) {
pos += vhdr->vendor_length;
left -= vhdr->vendor_length;
continue;
}
len = vhdr->vendor_length - sizeof(*vhdr);
data = malloc(len);
if (data == NULL)
return NULL;
memcpy(data, pos + sizeof(*vhdr), len);
if (alen)
*alen = len;
return data;
}
}
return NULL;
}
static u8 * decrypt_ms_key(const u8 *key, size_t len,
const u8 *req_authenticator,
const u8 *secret, size_t secret_len, size_t *reslen)
{
u8 *plain, *ppos, *res;
const u8 *pos;
size_t left, plen;
u8 hash[MD5_MAC_LEN];
int i, first = 1;
const u8 *addr[3];
size_t elen[3];
/* key: 16-bit salt followed by encrypted key info */
if (len < 2 + 16)
return NULL;
pos = key + 2;
left = len - 2;
if (left % 16) {
printf("Invalid ms key len %lu\n", (unsigned long) left);
return NULL;
}
plen = left;
ppos = plain = malloc(plen);
if (plain == NULL)
return NULL;
while (left > 0) {
/* b(1) = MD5(Secret + Request-Authenticator + Salt)
* b(i) = MD5(Secret + c(i - 1)) for i > 1 */
addr[0] = secret;
elen[0] = secret_len;
if (first) {
addr[1] = req_authenticator;
elen[1] = MD5_MAC_LEN;
addr[2] = key;
elen[2] = 2; /* Salt */
} else {
addr[1] = pos - MD5_MAC_LEN;
elen[1] = MD5_MAC_LEN;
}
md5_vector(first ? 3 : 2, addr, elen, hash);
first = 0;
for (i = 0; i < MD5_MAC_LEN; i++)
*ppos++ = *pos++ ^ hash[i];
left -= MD5_MAC_LEN;
}
if (plain[0] > plen - 1) {
printf("Failed to decrypt MPPE key\n");
free(plain);
return NULL;
}
res = malloc(plain[0]);
if (res == NULL) {
free(plain);
return NULL;
}
memcpy(res, plain + 1, plain[0]);
if (reslen)
*reslen = plain[0];
free(plain);
return res;
}
static void encrypt_ms_key(const u8 *key, size_t key_len, u16 salt,
const u8 *req_authenticator,
const u8 *secret, size_t secret_len,
u8 *ebuf, size_t *elen)
{
int i, len, first = 1;
u8 hash[MD5_MAC_LEN], saltbuf[2], *pos;
const u8 *addr[3];
size_t _len[3];
saltbuf[0] = salt >> 8;
saltbuf[1] = salt;
len = 1 + key_len;
if (len & 0x0f) {
len = (len & 0xf0) + 16;
}
memset(ebuf, 0, len);
ebuf[0] = key_len;
memcpy(ebuf + 1, key, key_len);
*elen = len;
pos = ebuf;
while (len > 0) {
/* b(1) = MD5(Secret + Request-Authenticator + Salt)
* b(i) = MD5(Secret + c(i - 1)) for i > 1 */
addr[0] = secret;
_len[0] = secret_len;
if (first) {
addr[1] = req_authenticator;
_len[1] = MD5_MAC_LEN;
addr[2] = saltbuf;
_len[2] = sizeof(saltbuf);
} else {
addr[1] = pos - MD5_MAC_LEN;
_len[1] = MD5_MAC_LEN;
}
md5_vector(first ? 3 : 2, addr, _len, hash);
first = 0;
for (i = 0; i < MD5_MAC_LEN; i++)
*pos++ ^= hash[i];
len -= MD5_MAC_LEN;
}
}
struct radius_ms_mppe_keys *
radius_msg_get_ms_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
u8 *secret, size_t secret_len)
{
u8 *key;
size_t keylen;
struct radius_ms_mppe_keys *keys;
if (msg == NULL || sent_msg == NULL)
return NULL;
keys = (struct radius_ms_mppe_keys *) malloc(sizeof(*keys));
if (keys == NULL)
return NULL;
memset(keys, 0, sizeof(*keys));
key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY,
&keylen);
if (key) {
keys->send = decrypt_ms_key(key, keylen,
sent_msg->hdr->authenticator,
secret, secret_len,
&keys->send_len);
free(key);
}
key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY,
&keylen);
if (key) {
keys->recv = decrypt_ms_key(key, keylen,
sent_msg->hdr->authenticator,
secret, secret_len,
&keys->recv_len);
free(key);
}
return keys;
}
struct radius_ms_mppe_keys *
radius_msg_get_cisco_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
u8 *secret, size_t secret_len)
{
u8 *key;
size_t keylen;
struct radius_ms_mppe_keys *keys;
if (msg == NULL || sent_msg == NULL)
return NULL;
keys = (struct radius_ms_mppe_keys *) malloc(sizeof(*keys));
if (keys == NULL)
return NULL;
memset(keys, 0, sizeof(*keys));
key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_CISCO,
RADIUS_CISCO_AV_PAIR, &keylen);
if (key && keylen == 51 && memcmp(key, "leap:session-key=", 17) == 0) {
keys->recv = decrypt_ms_key(key + 17, keylen - 17,
sent_msg->hdr->authenticator,
secret, secret_len,
&keys->recv_len);
}
free(key);
return keys;
}
int radius_msg_add_mppe_keys(struct radius_msg *msg,
const u8 *req_authenticator,
const u8 *secret, size_t secret_len,
const u8 *send_key, size_t send_key_len,
const u8 *recv_key, size_t recv_key_len)
{
struct radius_attr_hdr *attr;
u32 vendor_id = htonl(RADIUS_VENDOR_ID_MICROSOFT);
u8 *buf;
struct radius_attr_vendor *vhdr;
u8 *pos;
size_t elen;
int hlen;
u16 salt;
hlen = sizeof(vendor_id) + sizeof(*vhdr) + 2;
/* MS-MPPE-Send-Key */
buf = malloc(hlen + send_key_len + 16);
if (buf == NULL) {
return 0;
}
pos = buf;
memcpy(pos, &vendor_id, sizeof(vendor_id));
pos += sizeof(vendor_id);
vhdr = (struct radius_attr_vendor *) pos;
vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY;
pos = (u8 *) (vhdr + 1);
salt = random() | 0x8000;
*pos++ = salt >> 8;
*pos++ = salt;
encrypt_ms_key(send_key, send_key_len, salt, req_authenticator, secret,
secret_len, pos, &elen);
vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
buf, hlen + elen);
free(buf);
if (attr == NULL) {
return 0;
}
/* MS-MPPE-Recv-Key */
buf = malloc(hlen + send_key_len + 16);
if (buf == NULL) {
return 0;
}
pos = buf;
memcpy(pos, &vendor_id, sizeof(vendor_id));
pos += sizeof(vendor_id);
vhdr = (struct radius_attr_vendor *) pos;
vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY;
pos = (u8 *) (vhdr + 1);
salt ^= 1;
*pos++ = salt >> 8;
*pos++ = salt;
encrypt_ms_key(recv_key, recv_key_len, salt, req_authenticator, secret,
secret_len, pos, &elen);
vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
buf, hlen + elen);
free(buf);
if (attr == NULL) {
return 0;
}
return 1;
}
/* Add User-Password attribute to a RADIUS message and encrypt it as specified
* in RFC 2865, Chap. 5.2 */
struct radius_attr_hdr *
radius_msg_add_attr_user_password(struct radius_msg *msg,
u8 *data, size_t data_len,
u8 *secret, size_t secret_len)
{
u8 buf[128];
int padlen, i, pos;
size_t buf_len;
const u8 *addr[2];
size_t len[2];
u8 hash[16];
if (data_len > 128)
return NULL;
memcpy(buf, data, data_len);
buf_len = data_len;
padlen = data_len % 16;
if (padlen) {
padlen = 16 - padlen;
memset(buf + data_len, 0, padlen);
buf_len += padlen;
}
addr[0] = secret;
len[0] = secret_len;
addr[1] = msg->hdr->authenticator;
len[1] = 16;
md5_vector(2, addr, len, hash);
for (i = 0; i < 16; i++)
buf[i] ^= hash[i];
pos = 16;
while (pos < buf_len) {
addr[0] = secret;
len[0] = secret_len;
addr[1] = &buf[pos - 16];
len[1] = 16;
md5_vector(2, addr, len, hash);
for (i = 0; i < 16; i++)
buf[pos + i] ^= hash[i];
pos += 16;
}
return radius_msg_add_attr(msg, RADIUS_ATTR_USER_PASSWORD,
buf, buf_len);
}
int radius_msg_get_attr(struct radius_msg *msg, u8 type, u8 *buf, size_t len)
{
int i;
struct radius_attr_hdr *attr = NULL;
size_t dlen;
for (i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == type) {
attr = msg->attrs[i];
break;
}
}
if (!attr)
return -1;
dlen = attr->length - sizeof(*attr);
if (buf)
memcpy(buf, (attr + 1), dlen > len ? len : dlen);
return dlen;
}
int radius_msg_get_attr_ptr(struct radius_msg *msg, u8 type, u8 **buf,
size_t *len, const u8 *start)
{
int i;
struct radius_attr_hdr *attr = NULL;
for (i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == type &&
(start == NULL || (u8 *) msg->attrs[i] > start)) {
attr = msg->attrs[i];
break;
}
}
if (!attr)
return -1;
*buf = (u8 *) (attr + 1);
*len = attr->length - sizeof(*attr);
return 0;
}
int radius_msg_count_attr(struct radius_msg *msg, u8 type, int min_len)
{
int i, count;
for (count = 0, i = 0; i < msg->attr_used; i++) {
if (msg->attrs[i]->type == type &&
msg->attrs[i]->length >=
sizeof(struct radius_attr_hdr) + min_len)
count++;
}
return count;
}
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