File CVE-2024-3596.patch of Package freeradius-server.34053
Index: freeradius-server-3.0.16/raddb/radiusd.conf.in
===================================================================
--- freeradius-server-3.0.16.orig/raddb/radiusd.conf.in
+++ freeradius-server-3.0.16/raddb/radiusd.conf.in
@@ -480,6 +480,64 @@ security {
#
status_server = yes
+ #
+ # Global configuration for requiring Message-Authenticator
+ # in all Access-* packets sent over UDP or TCP. This flag
+ # is ignored for TLS.
+
+ #
+ # This flag sets the global default for all clients and home
+ # servers. It can be over-ridden in an individual client or
+ # home server definition by adding a flag to that section:
+ #
+ # require_message_authenticator = no
+ #
+ # If the server produces error message which says "Packet
+ # does not contain required Message-Authenticator attribute",
+ # then this configuration item has to be updated.
+ #
+ # WARNING: This item should always be left as "yes",
+ # otherwise it is possible for MITM attackers to create fake
+ # Access-Accept packets to the NAS!
+ #
+ require_message_authenticator = yes
+
+ #
+ # Global configuration for requiring Message-Authenticator
+ # Access-Request packets from a NAS, but only if those
+ # packets also contain Proxy-State. This flag only applies
+ # to packets sent over UDP or TCP. This flag is ignored for
+ # TLS.
+ #
+ # This flag sets the global default for all clients. It can
+ # be over-ridden in an individual client definition by adding
+ # a flag to that section:
+ #
+ # limit_proxy_state = no
+ #
+ # If "require_message_authenticator" is set to "yes", this
+ # configuration item is ignored.
+ #
+ # If "require_message_authenticator" is set to "no", this
+ # configuration item is checked.
+ #
+ # This configuration item should ALWAYS be set to "yes".
+ #
+ # The only reason to set it to "no" is when the client is a
+ # proxy, AND the proxy does not send Message-Authenticator in
+ # Access-Request packets. Even then, the best approach to
+ # fix the issue is to (1) update the proxy to send
+ # Message-Authenticator, and if that can't be done, then (2)
+ # set this flag to "no", but ONLY on a per-client basis.
+ #
+ # WARNING: Setting both this flag and the
+ # "require_message_authenticator" flag to "no" will allow
+ # MITM attackers to create fake Access-Accept packets to the
+ # NAS! At least one of them MUST be set to "yes" for the
+ # system to have any protection against the attack.
+ #
+ limit_proxy_state = yes
+
@openssl_version_check_config@
}
Index: freeradius-server-3.0.16/src/include/radiusd.h
===================================================================
--- freeradius-server-3.0.16.orig/src/include/radiusd.h
+++ freeradius-server-3.0.16/src/include/radiusd.h
@@ -169,6 +169,9 @@ typedef struct main_config {
bool exiting; //!< are we exiting?
+ bool require_ma; //!< global configuration for all clients and home servers
+
+ bool limit_proxy_state; //!< global configuration for all clients
#ifdef ENABLE_OPENSSL_VERSION_CHECK
char const *allow_vulnerable_openssl; //!< The CVE number of the last security issue acknowledged.
Index: freeradius-server-3.0.16/src/main/mainconfig.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/mainconfig.c
+++ freeradius-server-3.0.16/src/main/mainconfig.c
@@ -154,6 +154,8 @@ static const CONF_PARSER security_config
{ "max_attributes", FR_CONF_POINTER(PW_TYPE_INTEGER, &fr_max_attributes), STRINGIFY(0) },
{ "reject_delay", FR_CONF_POINTER(PW_TYPE_TIMEVAL, &main_config.reject_delay), STRINGIFY(0) },
{ "status_server", FR_CONF_POINTER(PW_TYPE_BOOLEAN, &main_config.status_server), "no"},
+ { "require_message_authenticator", FR_CONF_POINTER(PW_TYPE_BOOLEAN, &main_config.require_ma), "yes"},
+ { "limit_proxy_state", FR_CONF_POINTER(PW_TYPE_BOOLEAN, &main_config.limit_proxy_state), "yes"},
#ifdef ENABLE_OPENSSL_VERSION_CHECK
{ "allow_vulnerable_openssl", FR_CONF_POINTER(PW_TYPE_STRING, &main_config.allow_vulnerable_openssl), "no"},
#endif
Index: freeradius-server-3.0.16/src/include/clients.h
===================================================================
--- freeradius-server-3.0.16.orig/src/include/clients.h
+++ freeradius-server-3.0.16/src/include/clients.h
@@ -39,7 +39,9 @@ typedef struct radclient {
char const *secret; //!< Secret PSK.
- bool message_authenticator; //!< Require RADIUS message authenticator in requests.
+ bool require_ma; //!< Require RADIUS message authenticator in requests.
+
+ bool limit_proxy_state; //!< Limit Proxy-State in requests
char const *nas_type; //!< Type of client (arbitrary).
Index: freeradius-server-3.0.16/src/main/client.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/client.c
+++ freeradius-server-3.0.16/src/main/client.c
@@ -315,7 +315,8 @@ bool client_add(RADCLIENT_LIST *clients,
(old->coa_server == client->coa_server) &&
(old->coa_pool == client->coa_pool) &&
#endif
- (old->message_authenticator == client->message_authenticator)) {
+ (old->require_ma == client->require_ma) &&
+ (old->limit_proxy_state == client->limit_proxy_state)) {
WARN("Ignoring duplicate client %s", client->longname);
client_free(client);
return true;
@@ -501,7 +502,8 @@ static const CONF_PARSER client_config[]
{ "src_ipaddr", FR_CONF_POINTER(PW_TYPE_STRING, &cl_srcipaddr), NULL },
- { "require_message_authenticator", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, RADCLIENT, message_authenticator), "no" },
+ { "require_message_authenticator", FR_CONF_OFFSET(PW_TYPE_BOOLEAN | PW_TYPE_IGNORE_DEFAULT, RADCLIENT, require_ma), NULL },
+ { "limit_proxy_state", FR_CONF_OFFSET(PW_TYPE_BOOLEAN | PW_TYPE_IGNORE_DEFAULT, RADCLIENT, limit_proxy_state), NULL },
{ "secret", FR_CONF_OFFSET(PW_TYPE_STRING | PW_TYPE_SECRET, RADCLIENT, secret), NULL },
{ "shortname", FR_CONF_OFFSET(PW_TYPE_STRING, RADCLIENT, shortname), NULL },
@@ -697,7 +699,7 @@ static const CONF_PARSER dynamic_config[
{ "FreeRADIUS-Client-Src-IP-Address", FR_CONF_OFFSET(PW_TYPE_IPV4_ADDR, RADCLIENT, src_ipaddr), NULL },
{ "FreeRADIUS-Client-Src-IPv6-Address", FR_CONF_OFFSET(PW_TYPE_IPV6_ADDR, RADCLIENT, src_ipaddr), NULL },
- { "FreeRADIUS-Client-Require-MA", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, RADCLIENT, message_authenticator), NULL },
+ { "FreeRADIUS-Client-Require-MA", FR_CONF_OFFSET(PW_TYPE_BOOLEAN, RADCLIENT, require_ma), NULL },
{ "FreeRADIUS-Client-Secret", FR_CONF_OFFSET(PW_TYPE_STRING, RADCLIENT, secret), "" },
{ "FreeRADIUS-Client-Shortname", FR_CONF_OFFSET(PW_TYPE_STRING, RADCLIENT, shortname), "" },
@@ -879,6 +881,15 @@ RADCLIENT *client_afrom_cs(TALLOC_CTX *c
c = talloc_zero(ctx, RADCLIENT);
c->cs = cs;
+ /*
+ * Set the "require message authenticator" and "limit
+ * proxy state" flags from the global default. If the
+ * configuration item exists, AND is set, it will
+ * over-ride the flag.
+ */
+ c->require_ma = main_config.require_ma;
+ c->limit_proxy_state = main_config.limit_proxy_state;
+
memset(&cl_ipaddr, 0, sizeof(cl_ipaddr));
cl_netmask = 255;
@@ -1192,7 +1203,7 @@ RADCLIENT *client_afrom_query(TALLOC_CTX
if (shortname) c->shortname = talloc_typed_strdup(c, shortname);
if (type) c->nas_type = talloc_typed_strdup(c, type);
if (server) c->server = talloc_typed_strdup(c, server);
- c->message_authenticator = require_ma;
+ c->require_ma = require_ma;
return c;
}
Index: freeradius-server-3.0.16/src/main/listen.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/listen.c
+++ freeradius-server-3.0.16/src/main/listen.c
@@ -1536,7 +1536,7 @@ static int auth_socket_recv(rad_listen_t
* Now that we've sanity checked everything, receive the
* packet.
*/
- packet = rad_recv(ctx, listener->fd, client->message_authenticator);
+ packet = rad_recv(ctx, listener->fd, client->require_ma | (((int) client->limit_proxy_state) << 2));
if (!packet) {
FR_STATS_INC(auth, total_malformed_requests);
if (DEBUG_ENABLED) ERROR("Receive - %s", fr_strerror());
@@ -1929,7 +1929,7 @@ static int coa_socket_recv(rad_listen_t
* Now that we've sanity checked everything, receive the
* packet.
*/
- packet = rad_recv(ctx, listener->fd, client->message_authenticator);
+ packet = rad_recv(ctx, listener->fd, client->require_ma);
if (!packet) {
FR_STATS_INC(coa, total_malformed_requests);
if (DEBUG_ENABLED) ERROR("Receive - %s", fr_strerror());
Index: freeradius-server-3.0.16/src/include/conffile.h
===================================================================
--- freeradius-server-3.0.16.orig/src/include/conffile.h
+++ freeradius-server-3.0.16/src/include/conffile.h
@@ -140,6 +140,7 @@ typedef struct timeval _timeval_t;
#define PW_TYPE_MULTI (1 << 18) //!< CONF_PAIR can have multiple copies.
#define PW_TYPE_NOT_EMPTY (1 << 19) //!< CONF_PAIR is required to have a non zero length value.
#define PW_TYPE_FILE_EXISTS ((1 << 20) | PW_TYPE_STRING) //!< File matching value must exist
+#define PW_TYPE_IGNORE_DEFAULT (1 << 21) //!< don't set from .dflt if the CONF_PAIR is missing
/* @} **/
#define FR_INTEGER_COND_CHECK(_name, _var, _cond, _new)\
Index: freeradius-server-3.0.16/src/main/conffile.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/conffile.c
+++ freeradius-server-3.0.16/src/main/conffile.c
@@ -1388,6 +1388,7 @@ int cf_item_parse(CONF_SECTION *cs, char
{
int rcode;
bool deprecated, required, attribute, secret, file_input, cant_be_empty, tmpl, multi, file_exists;
+ bool ignore_dflt;
char **q;
char const *value;
CONF_PAIR *cp = NULL;
@@ -1408,6 +1409,7 @@ int cf_item_parse(CONF_SECTION *cs, char
cant_be_empty = (type & PW_TYPE_NOT_EMPTY);
tmpl = (type & PW_TYPE_TMPL);
multi = (type & PW_TYPE_MULTI);
+ ignore_dflt = (type & PW_TYPE_IGNORE_DEFAULT);
if (attribute) required = true;
if (required) cant_be_empty = true; /* May want to review this in the future... */
@@ -1431,7 +1433,7 @@ int cf_item_parse(CONF_SECTION *cs, char
* section, use the default value.
*/
if (!cp) {
- if (deprecated) return 0; /* Don't set the default value */
+ if (deprecated || ignore_dflt) return 0; /* Don't set the default value */
rcode = 1;
value = dflt;
Index: freeradius-server-3.0.16/raddb/clients.conf
===================================================================
--- freeradius-server-3.0.16.orig/raddb/clients.conf
+++ freeradius-server-3.0.16/raddb/clients.conf
@@ -100,15 +100,30 @@ client localhost {
secret = testing123
#
- # Old-style clients do not send a Message-Authenticator
- # in an Access-Request. RFC 5080 suggests that all clients
- # SHOULD include it in an Access-Request. The configuration
- # item below allows the server to require it. If a client
- # is required to include a Message-Authenticator and it does
- # not, then the packet will be silently discarded.
+ # The global configuration "security.require_message_authenticator"
+ # flag sets the default for all clients. That default can be
+ # over-ridden here, by setting it to "no".
+ #
+ # This flag exists solely for legacy clients which do not send
+ # Message-Authenticator in all Access-Request packets. We do not
+ # recommend setting it to "no".
+ #
+ # allowed values: yes, no
+ #
+# require_message_authenticator = yes
+
+ #
+ # The global configuration "security.limit_proxy_state"
+ # flag sets the default for all clients. That default can be
+ # over-ridden here, by setting it to "no".
+ #
+ # This flag exists solely for legacy clients which do not send
+ # Message-Authenticator in all Access-Request packets. We do not
+ # recommend setting it to "no".
#
# allowed values: yes, no
- require_message_authenticator = no
+ #
+# limit_proxy_state = yes
#
# The short name is used as an alias for the fully qualified
Index: freeradius-server-3.0.16/src/include/libradius.h
===================================================================
--- freeradius-server-3.0.16.orig/src/include/libradius.h
+++ freeradius-server-3.0.16/src/include/libradius.h
@@ -404,6 +404,7 @@ typedef struct radius_packet {
size_t partial;
int proto;
#endif
+ bool tls; //!< uses secure transport
} RADIUS_PACKET;
typedef enum {
@@ -509,6 +510,11 @@ DICT_VENDOR *dict_vendorbyvalue(int vend
/* radius.c */
int rad_send(RADIUS_PACKET *, RADIUS_PACKET const *, char const *secret);
bool rad_packet_ok(RADIUS_PACKET *packet, int flags, decode_fail_t *reason);
+/*
+ * 1 == require_ma
+ * 2 == msg_peek
+ * 3 == limit_proxy_state
+ */
RADIUS_PACKET *rad_recv(TALLOC_CTX *ctx, int fd, int flags);
ssize_t rad_recv_header(int sockfd, fr_ipaddr_t *src_ipaddr, uint16_t *src_port, int *code);
void rad_recv_discard(int sockfd);
Index: freeradius-server-3.0.16/src/main/tls_listen.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/tls_listen.c
+++ freeradius-server-3.0.16/src/main/tls_listen.c
@@ -299,6 +299,8 @@ get_application_data:
packet->vps = NULL;
PTHREAD_MUTEX_UNLOCK(&sock->mutex);
+ packet->tls = true;
+
if (!rad_packet_ok(packet, 0, NULL)) {
if (DEBUG_ENABLED) ERROR("Receive - %s", fr_strerror());
DEBUG("Closing TLS socket from client");
@@ -712,6 +714,8 @@ int proxy_tls_recv(rad_listen_t *listene
memcpy(packet->data, data, packet->data_len);
memcpy(packet->vector, packet->data + 4, 16);
+ packet->tls = true;
+
/*
* FIXME: Client MIB updates?
*/
@@ -764,6 +768,7 @@ int proxy_tls_send(rad_listen_t *listene
* if there's no packet, encode it here.
*/
if (!request->proxy->data) {
+ request->reply->tls = true;
request->proxy_listener->encode(request->proxy_listener,
request);
}
Index: freeradius-server-3.0.16/src/lib/radius.c
===================================================================
--- freeradius-server-3.0.16.orig/src/lib/radius.c
+++ freeradius-server-3.0.16/src/lib/radius.c
@@ -1740,6 +1740,7 @@ int rad_encode(RADIUS_PACKET *packet, RA
uint16_t total_length;
int len;
VALUE_PAIR const *reply;
+ bool seen_ma = false;
/*
* A 4K packet, aligned on 64-bits.
@@ -1804,6 +1805,27 @@ int rad_encode(RADIUS_PACKET *packet, RA
*/
/*
+ * Always add Message-Authenticator for replies to
+ * Access-Request packets.
+ *
+ * It must be the FIRST attribute in the packet.
+ */
+ if (!packet->tls &&
+ ((original && (original->code == PW_CODE_ACCESS_REQUEST)) ||
+ (packet->code == PW_CODE_ACCESS_REQUEST))) {
+ seen_ma = true;
+
+ packet->offset = RADIUS_HDR_LEN;
+
+ ptr[0] = PW_MESSAGE_AUTHENTICATOR;
+ ptr[1] = 18;
+ memset(ptr + 2, 0, 16);
+
+ ptr += 18;
+ total_length += 18;
+ }
+
+ /*
* Loop over the reply attributes for the packet.
*/
reply = packet->vps;
@@ -1850,11 +1872,20 @@ int rad_encode(RADIUS_PACKET *packet, RA
}
}
+ room = ((uint8_t *) data) + sizeof(data) - ptr;
+
/*
* Set the Message-Authenticator to the correct
* length and initial value.
*/
if (!reply->da->vendor && (reply->da->attr == PW_MESSAGE_AUTHENTICATOR)) {
+ // don't encode Message-Authenticator twice
+ if (seen_ma) {
+ reply = reply->next;
+ continue;
+ }
+ if (room < 18) break;
+
/*
* Cache the offset to the
* Message-Authenticator
@@ -1866,8 +1897,6 @@ int rad_encode(RADIUS_PACKET *packet, RA
}
last_name = reply->da->name;
- room = ((uint8_t *) data) + sizeof(data) - ptr;
-
if (room <= 2) break;
len = rad_vp2attr(packet, original, secret, &reply, ptr, room);
@@ -2341,6 +2370,8 @@ bool rad_packet_ok(RADIUS_PACKET *packet
radius_packet_t *hdr;
char host_ipaddr[128];
bool require_ma = false;
+ bool limit_proxy_state = false;
+ bool seen_proxy_state = false;
bool seen_ma = false;
uint32_t num_attributes;
decode_fail_t failure = DECODE_FAIL_NONE;
@@ -2391,13 +2422,14 @@ bool rad_packet_ok(RADIUS_PACKET *packet
/*
* Message-Authenticator is required in Status-Server
* packets, otherwise they can be trivially forged.
- */
- if (hdr->code == PW_CODE_STATUS_SERVER) require_ma = true;
-
- /*
+ *
* It's also required if the caller asks for it.
+ *
+ * We only limit Proxy-State if we're not requiring
+ * Message-Authenticator.
*/
- if (flags) require_ma = true;
+ require_ma = ((flags & 0x01) != 0) || (hdr->code == PW_CODE_STATUS_SERVER);
+ limit_proxy_state = ((flags & 0x04) != 0) & !require_ma;
/*
* Repeat the length checks. This time, instead of
@@ -2560,6 +2592,10 @@ bool rad_packet_ok(RADIUS_PACKET *packet
non_eap = true;
break;
+ case PW_PROXY_STATE:
+ seen_proxy_state = true;
+ break;
+
case PW_MESSAGE_AUTHENTICATOR:
if (attr[1] != 2 + AUTH_VECTOR_LEN) {
FR_DEBUG_STRERROR_PRINTF("Malformed RADIUS packet from host %s: Message-Authenticator has invalid length %d",
@@ -2631,6 +2667,18 @@ bool rad_packet_ok(RADIUS_PACKET *packet
inet_ntop(packet->src_ipaddr.af,
&packet->src_ipaddr.ipaddr,
host_ipaddr, sizeof(host_ipaddr)));
+ failure = DECODE_FAIL_MA_MISSING;
+ goto finish;
+ }
+
+ /*
+ * The client is a NAS which shouldn't send Proxy-State, but it did!
+ */
+ if (limit_proxy_state && seen_proxy_state && !seen_ma) {
+ FR_DEBUG_STRERROR_PRINTF("Insecure packet from host %s: Packet does not contain required Message-Authenticator attribute, but still has one or more Proxy-State attributes",
+ inet_ntop(packet->src_ipaddr.af,
+ &packet->src_ipaddr.ipaddr,
+ host_ipaddr, sizeof(host_ipaddr)));
failure = DECODE_FAIL_MA_MISSING;
goto finish;
}
Index: freeradius-server-3.0.16/raddb/proxy.conf
===================================================================
--- freeradius-server-3.0.16.orig/raddb/proxy.conf
+++ freeradius-server-3.0.16/raddb/proxy.conf
@@ -204,6 +204,20 @@ home_server localhost {
#
secret = testing123
+ # The global configuration "security.require_message_authenticator"
+ # flag sets the default for all home servers. That default can be
+ # over-ridden here, by setting it to "no".
+ #
+ # This flag exists solely for legacy home servers which do
+ # not send Message-Authenticator in all Access-Accept,
+ # Access-Reject, or Access-Challenge packets. We do not
+ # recommend setting it to "no".
+ #
+ # allowed values: yes, no
+ #
+ #require_message_authenticator = no
+
+
############################################################
#
# The rest of the configuration items listed here are optional,
Index: freeradius-server-3.0.16/src/include/realms.h
===================================================================
--- freeradius-server-3.0.16.orig/src/include/realms.h
+++ freeradius-server-3.0.16/src/include/realms.h
@@ -58,6 +58,8 @@ typedef struct home_server {
//!< stats or when specifying home servers for a pool.
bool dual; //!< One of a pair of homeservers on consecutive ports.
+ bool require_ma; //!< for all replies to Access-Request and Status-Server
+
char const *server; //!< For internal proxying
char const *parent_server;
Index: freeradius-server-3.0.16/src/main/process.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/process.c
+++ freeradius-server-3.0.16/src/main/process.c
@@ -2489,11 +2489,32 @@ int request_proxy_reply(RADIUS_PACKET *p
* ignore it. This does the MD5 calculations in the
* server core, but I guess we can fix that later.
*/
- if (!request->proxy_reply &&
- (rad_verify(packet, request->proxy,
- request->home_server->secret) != 0)) {
- DEBUG("Ignoring spoofed proxy reply. Signature is invalid");
- return 0;
+ if (!request->proxy_reply) {
+ decode_fail_t reason;
+
+ /*
+ * If the home server configuration requires a Message-Authenticator, then set the flag,
+ * but only if the proxied packet is Access-Request or Status-Sercer.
+ *
+ * The realms.c file already clears require_ma for TLS connections.
+ */
+ bool require_ma = request->home_server->require_ma && (request->proxy->code == PW_CODE_ACCESS_REQUEST);
+
+ if (!request->home_server) {
+ proxy_reply_too_late(request);
+ return 0;
+ }
+
+ if (!rad_packet_ok(packet, require_ma, &reason)) {
+ DEBUG("Ignoring invalid packet - %s", fr_strerror());
+ return 0;
+ }
+
+ if (rad_verify(packet, request->proxy,
+ request->home_server->secret) != 0) {
+ DEBUG("Ignoring spoofed proxy reply. Signature is invalid");
+ return 0;
+ }
}
/*
Index: freeradius-server-3.0.16/src/main/realms.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/realms.c
+++ freeradius-server-3.0.16/src/main/realms.c
@@ -363,6 +363,7 @@ static CONF_PARSER home_server_coa[] = {
#endif
static CONF_PARSER home_server_config[] = {
+ { "require_message_authenticator", FR_CONF_OFFSET(PW_TYPE_BOOLEAN | PW_TYPE_IGNORE_DEFAULT, home_server_t, require_ma), NULL },
{ "ipaddr", FR_CONF_OFFSET(PW_TYPE_COMBO_IP_ADDR, home_server_t, ipaddr), NULL },
{ "ipv4addr", FR_CONF_OFFSET(PW_TYPE_IPV4_ADDR, home_server_t, ipaddr), NULL },
{ "ipv6addr", FR_CONF_OFFSET(PW_TYPE_IPV6_ADDR, home_server_t, ipaddr), NULL },
@@ -636,6 +637,7 @@ home_server_t *home_server_afrom_cs(TALL
home->cs = cs;
home->state = HOME_STATE_UNKNOWN;
home->proto = IPPROTO_UDP;
+ home->require_ma = main_config.require_ma;
/*
* Parse the configuration into the home server
@@ -920,6 +922,11 @@ home_server_t *home_server_afrom_cs(TALL
* Parse the SSL client configuration.
*/
if (tls) {
+ /*
+ * We don't require this for TLS connections.
+ */
+ home->require_ma = false;
+
home->tls = tls_client_conf_parse(tls);
if (!home->tls) {
goto error;
Index: freeradius-server-3.0.16/man/man1/radclient.1
===================================================================
--- freeradius-server-3.0.16.orig/man/man1/radclient.1
+++ freeradius-server-3.0.16/man/man1/radclient.1
@@ -5,6 +5,7 @@ radclient - send packets to a RADIUS ser
.B radclient
.RB [ \-4 ]
.RB [ \-6 ]
+.RB [ \-b ]
.RB [ \-c
.IR count ]
.RB [ \-d
@@ -52,6 +53,13 @@ automatically encrypted before the packe
Use IPv4 (default)
.IP \-6
Use IPv6
+.IP \-b
+Enforce the Blast RADIUS checks. All replies to an Access-Request packet
+must contain a Message-Authenticator as the first attribute.
+
+For compatibility with old servers, this flag is not set by default.
+However, radclient still checks for the Blast RADIUS signature, and
+discards packets which match the attack.
.IP \-c\ \fIcount\fP
Send each packet \fIcount\fP times.
.IP \-d\ \fIraddb_directory\fP
Index: freeradius-server-3.0.16/src/main/radclient.c
===================================================================
--- freeradius-server-3.0.16.orig/src/main/radclient.c
+++ freeradius-server-3.0.16/src/main/radclient.c
@@ -53,6 +53,7 @@ static fr_ipaddr_t server_ipaddr;
static int resend_count = 1;
static bool done = true;
static bool print_filename = false;
+static bool blast_radius = false;
static fr_ipaddr_t client_ipaddr;
static uint16_t client_port = 0;
@@ -89,6 +90,7 @@ static void NEVER_RETURNS usage(void)
fprintf(stderr, " <command> One of auth, acct, status, coa, disconnect or auto.\n");
fprintf(stderr, " -4 Use IPv4 address of server\n");
fprintf(stderr, " -6 Use IPv6 address of server.\n");
+ fprintf(stderr, " -b Mandate checks for Blast RADIUS issue (this is not set by default).\n");
fprintf(stderr, " -c <count> Send each packet 'count' times.\n");
fprintf(stderr, " -d <raddb> Set user dictionary directory (defaults to " RADDBDIR ").\n");
fprintf(stderr, " -D <dictdir> Set main dictionary directory (defaults to " DICTDIR ").\n");
@@ -989,6 +991,131 @@ static int send_one_packet(rc_request_t
}
/*
+ * Do Blast RADIUS checks.
+ *
+ * The request is an Access-Request, and does NOT contain Proxy-State.
+ *
+ * The reply is a raw packet, and is NOT yet decoded.
+ */
+static int blast_radius_check(rc_request_t *request, RADIUS_PACKET *reply)
+{
+ uint8_t *attr, *end;
+ VALUE_PAIR *vp;
+ bool have_message_authenticator = false;
+
+ /*
+ * We've received a raw packet. Nothing has (as of yet) checked
+ * anything in it other than the length, and that it's a
+ * well-formed RADIUS packet.
+ */
+ switch (reply->data[0]) {
+ case PW_CODE_ACCESS_ACCEPT:
+ case PW_CODE_ACCESS_REJECT:
+ case PW_CODE_ACCESS_CHALLENGE:
+ if (reply->data[1] != request->packet->id) {
+ ERROR("Invalid reply ID %d to Access-Request ID %d", reply->data[1], request->packet->id);
+ return -1;
+ }
+ break;
+
+ default:
+ ERROR("Invalid reply code %d to Access-Request", reply->data[0]);
+ return -1;
+ }
+
+ /*
+ * If the reply has a Message-Authenticator, then it MIGHT be fine.
+ */
+ attr = reply->data + 20;
+ end = reply->data + reply->data_len;
+
+ /*
+ * It should be the first attribute, so we warn if it isn't there.
+ *
+ * But it's not a fatal error.
+ */
+ if (blast_radius && (attr[0] != PW_MESSAGE_AUTHENTICATOR)) {
+ RDEBUG("WARNING The %s reply packet does not have Message-Authenticator as the first attribute. The packet may be vulnerable to Blast RADIUS attacks.",
+ fr_packet_codes[reply->data[0]]);
+ }
+
+ /*
+ * Set up for Proxy-State checks.
+ *
+ * If we see a Proxy-State in the reply which we didn't send, then it's a Blast RADIUS attack.
+ */
+ vp = fr_pair_find_by_num(request->packet->vps, PW_PROXY_STATE, 0, TAG_ANY);
+
+ while (attr < end) {
+ /*
+ * Blast RADIUS work-arounds require that
+ * Message-Authenticator is the first attribute in the
+ * reply. Note that we don't check for it being the
+ * first attribute, but simply that it exists.
+ *
+ * That check is a balance between securing the reply
+ * packet from attacks, and not violating the RFCs which
+ * say that there is no order to attributes in the
+ * packet.
+ *
+ * However, no matter the status of the '-b' flag we
+ * still can check for the signature of the attack, and
+ * discard packets which are suspicious. This behavior
+ * protects radclient from the attack, without mandating
+ * new behavior on the server side.
+ *
+ * Note that we don't set the '-b' flag by default.
+ * radclient is intended for testing / debugging, and is
+ * not intended to be used as part of a secure login /
+ * user checking system.
+ */
+ if (attr[0] == PW_MESSAGE_AUTHENTICATOR) {
+ have_message_authenticator = true;
+ goto next;
+ }
+
+ /*
+ * If there are Proxy-State attributes in the reply, they must
+ * match EXACTLY the Proxy-State attributes in the request.
+ *
+ * Note that we don't care if there are more Proxy-States
+ * in the request than in the reply. The Blast RADIUS
+ * issue requires _adding_ Proxy-State attributes, and
+ * cannot work when the server _deletes_ Proxy-State
+ * attributes.
+ */
+ if (attr[0] == PW_PROXY_STATE) {
+ if (!vp || (vp->length != (size_t) (attr[1] - 2)) || (memcmp(vp->vp_octets, attr + 2, vp->length) != 0)) {
+ ERROR("Invalid reply to Access-Request ID %d - Discarding packet due to Blast RADIUS attack being detected.", request->packet->id);
+ ERROR("We received a Proxy-State in the reply which we did not send, or which is different from what we sent.");
+ return -1;
+ }
+
+ vp = fr_pair_find_by_num(vp->next, PW_PROXY_STATE, 0, TAG_ANY);
+ }
+
+ next:
+ attr += attr[1];
+ }
+
+ /*
+ * If "-b" is set, then we require Message-Authenticator in the reply.
+ */
+ if (blast_radius && !have_message_authenticator) {
+ ERROR("The %s reply packet does not contain Message-Authenticator - discarding packet due to Blast RADIUS checks.",
+ fr_packet_codes[reply->data[0]]);
+ return -1;
+ }
+
+ /*
+ * The packet doesn't look like it's a Blast RADIUS attack. The
+ * caller will now verify the packet signature.
+ */
+ return 0;
+}
+
+
+/*
* Receive one packet, maybe.
*/
static int recv_one_packet(int wait_time)
@@ -1066,6 +1193,20 @@ static int recv_one_packet(int wait_time
request = fr_packet2myptr(rc_request_t, packet, packet_p);
/*
+ * We want radclient to be able to send any packet, including
+ * imperfect ones. However, we do NOT want to be vulnerable to
+ * the "Blast RADIUS" issue. Instead of adding command-line
+ * flags to enable/disable similar flags to what the server
+ * sends, we just do a few more smart checks to double-check
+ * things.
+ */
+ if ((request->packet->code == PW_CODE_ACCESS_REQUEST) &&
+ blast_radius_check(request, reply) < 0) {
+ rad_free(&reply);
+ return -1;
+ }
+
+ /*
* Fails the signature validation: not a real reply.
* FIXME: Silently drop it and listen for another packet.
*/
@@ -1195,7 +1336,7 @@ int main(int argc, char **argv)
exit(1);
}
- while ((c = getopt(argc, argv, "46c:d:D:f:Fhi:n:p:qr:sS:t:vx"
+ while ((c = getopt(argc, argv, "46bc:d:D:f:Fhi:n:p:qr:sS:t:vx"
#ifdef WITH_TCP
"P:"
#endif
@@ -1208,6 +1349,10 @@ int main(int argc, char **argv)
force_af = AF_INET6;
break;
+ case 'b':
+ blast_radius = true;
+ break;
+
case 'c':
if (!isdigit((int) *optarg))
usage();
