[PATCH net-next 05/17] rxrpc: Don't retain the server key in the connection
David Howells
dhowells at redhat.com
Mon Nov 23 15:10:39 EST 2020
Don't retain a pointer to the server key in the connection, but rather get
it on demand when the server has to deal with a response packet.
This is necessary to implement RxGK (GSSAPI-mediated transport class),
where we can't know which key we'll need until we've challenged the client
and got back the response.
This also means that we don't need to do a key search in the accept path in
softirq mode.
Also, whilst we're at it, allow the security class to ask for a kvno and
encoding-type variant of a server key as RxGK needs different keys for
different encoding types. Keys of this type have an extra bit in the
description:
"<service-id>:<security-index>:<kvno>:<enctype>"
Signed-off-by: David Howells <dhowells at redhat.com>
---
net/rxrpc/ar-internal.h | 11 +++---
net/rxrpc/call_accept.c | 14 ++++----
net/rxrpc/conn_event.c | 1 -
net/rxrpc/conn_object.c | 1 -
net/rxrpc/conn_service.c | 2 -
net/rxrpc/rxkad.c | 57 ++++++++++++++++++--------------
net/rxrpc/security.c | 81 ++++++++++++++++++++++++++++++++--------------
7 files changed, 100 insertions(+), 67 deletions(-)
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 3c417ec94e4c..db6e754743fb 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -441,7 +441,6 @@ struct rxrpc_connection {
struct list_head link; /* link in master connection list */
struct sk_buff_head rx_queue; /* received conn-level packets */
const struct rxrpc_security *security; /* applied security module */
- struct key *server_key; /* security for this service */
struct crypto_sync_skcipher *cipher; /* encryption handle */
struct rxrpc_crypt csum_iv; /* packet checksum base */
unsigned long flags;
@@ -890,8 +889,7 @@ struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
struct sk_buff *);
struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *, gfp_t);
void rxrpc_new_incoming_connection(struct rxrpc_sock *, struct rxrpc_connection *,
- const struct rxrpc_security *, struct key *,
- struct sk_buff *);
+ const struct rxrpc_security *, struct sk_buff *);
void rxrpc_unpublish_service_conn(struct rxrpc_connection *);
/*
@@ -1056,9 +1054,10 @@ extern const struct rxrpc_security rxkad;
int __init rxrpc_init_security(void);
void rxrpc_exit_security(void);
int rxrpc_init_client_conn_security(struct rxrpc_connection *);
-bool rxrpc_look_up_server_security(struct rxrpc_local *, struct rxrpc_sock *,
- const struct rxrpc_security **, struct key **,
- struct sk_buff *);
+const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *,
+ struct sk_buff *);
+struct key *rxrpc_look_up_server_security(struct rxrpc_connection *,
+ struct sk_buff *, u32, u32);
/*
* sendmsg.c
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 8df1964db333..382add72c66f 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -261,7 +261,6 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
struct rxrpc_peer *peer,
struct rxrpc_connection *conn,
const struct rxrpc_security *sec,
- struct key *key,
struct sk_buff *skb)
{
struct rxrpc_backlog *b = rx->backlog;
@@ -309,7 +308,7 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
conn->params.local = rxrpc_get_local(local);
conn->params.peer = peer;
rxrpc_see_connection(conn);
- rxrpc_new_incoming_connection(rx, conn, sec, key, skb);
+ rxrpc_new_incoming_connection(rx, conn, sec, skb);
} else {
rxrpc_get_connection(conn);
}
@@ -353,7 +352,6 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
struct rxrpc_connection *conn;
struct rxrpc_peer *peer = NULL;
struct rxrpc_call *call = NULL;
- struct key *key = NULL;
_enter("");
@@ -374,11 +372,13 @@ struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
*/
conn = rxrpc_find_connection_rcu(local, skb, &peer);
- if (!conn && !rxrpc_look_up_server_security(local, rx, &sec, &key, skb))
- goto no_call;
+ if (!conn) {
+ sec = rxrpc_get_incoming_security(rx, skb);
+ if (!sec)
+ goto no_call;
+ }
- call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, key, skb);
- key_put(key);
+ call = rxrpc_alloc_incoming_call(rx, local, peer, conn, sec, skb);
if (!call) {
skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
goto no_call;
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index bbf86203ed25..03a482ba770f 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -378,7 +378,6 @@ static void rxrpc_secure_connection(struct rxrpc_connection *conn)
_enter("{%d}", conn->debug_id);
ASSERT(conn->security_ix != 0);
- ASSERT(conn->server_key);
if (conn->security->issue_challenge(conn) < 0) {
abort_code = RX_CALL_DEAD;
diff --git a/net/rxrpc/conn_object.c b/net/rxrpc/conn_object.c
index 3bcbe0665f91..8dd1ef25b98f 100644
--- a/net/rxrpc/conn_object.c
+++ b/net/rxrpc/conn_object.c
@@ -363,7 +363,6 @@ static void rxrpc_destroy_connection(struct rcu_head *rcu)
conn->security->clear(conn);
key_put(conn->params.key);
- key_put(conn->server_key);
rxrpc_put_bundle(conn->bundle);
rxrpc_put_peer(conn->params.peer);
diff --git a/net/rxrpc/conn_service.c b/net/rxrpc/conn_service.c
index 6c847720494f..e1966dfc9152 100644
--- a/net/rxrpc/conn_service.c
+++ b/net/rxrpc/conn_service.c
@@ -156,7 +156,6 @@ struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *rxn
void rxrpc_new_incoming_connection(struct rxrpc_sock *rx,
struct rxrpc_connection *conn,
const struct rxrpc_security *sec,
- struct key *key,
struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
@@ -170,7 +169,6 @@ void rxrpc_new_incoming_connection(struct rxrpc_sock *rx,
conn->security_ix = sp->hdr.securityIndex;
conn->out_clientflag = 0;
conn->security = sec;
- conn->server_key = key_get(key);
if (conn->security_ix)
conn->state = RXRPC_CONN_SERVICE_UNSECURED;
else
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 404d1323c239..0d21935dac27 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -647,11 +647,7 @@ static int rxkad_issue_challenge(struct rxrpc_connection *conn)
u32 serial;
int ret;
- _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
-
- ret = key_validate(conn->server_key);
- if (ret < 0)
- return ret;
+ _enter("{%d}", conn->debug_id);
get_random_bytes(&conn->security_nonce, sizeof(conn->security_nonce));
@@ -891,6 +887,7 @@ static int rxkad_respond_to_challenge(struct rxrpc_connection *conn,
* decrypt the kerberos IV ticket in the response
*/
static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
+ struct key *server_key,
struct sk_buff *skb,
void *ticket, size_t ticket_len,
struct rxrpc_crypt *_session_key,
@@ -910,30 +907,17 @@ static int rxkad_decrypt_ticket(struct rxrpc_connection *conn,
u32 abort_code;
u8 *p, *q, *name, *end;
- _enter("{%d},{%x}", conn->debug_id, key_serial(conn->server_key));
+ _enter("{%d},{%x}", conn->debug_id, key_serial(server_key));
*_expiry = 0;
- ret = key_validate(conn->server_key);
- if (ret < 0) {
- switch (ret) {
- case -EKEYEXPIRED:
- abort_code = RXKADEXPIRED;
- goto other_error;
- default:
- abort_code = RXKADNOAUTH;
- goto other_error;
- }
- }
-
- ASSERT(conn->server_key->payload.data[0] != NULL);
+ ASSERT(server_key->payload.data[0] != NULL);
ASSERTCMP((unsigned long) ticket & 7UL, ==, 0);
- memcpy(&iv, &conn->server_key->payload.data[2], sizeof(iv));
+ memcpy(&iv, &server_key->payload.data[2], sizeof(iv));
ret = -ENOMEM;
- req = skcipher_request_alloc(conn->server_key->payload.data[0],
- GFP_NOFS);
+ req = skcipher_request_alloc(server_key->payload.data[0], GFP_NOFS);
if (!req)
goto temporary_error;
@@ -1089,6 +1073,7 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
struct rxkad_response *response;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_crypt session_key;
+ struct key *server_key;
const char *eproto;
time64_t expiry;
void *ticket;
@@ -1096,7 +1081,27 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
__be32 csum;
int ret, i;
- _enter("{%d,%x}", conn->debug_id, key_serial(conn->server_key));
+ _enter("{%d}", conn->debug_id);
+
+ server_key = rxrpc_look_up_server_security(conn, skb, 0, 0);
+ if (IS_ERR(server_key)) {
+ switch (PTR_ERR(server_key)) {
+ case -ENOKEY:
+ abort_code = RXKADUNKNOWNKEY;
+ break;
+ case -EKEYEXPIRED:
+ abort_code = RXKADEXPIRED;
+ break;
+ default:
+ abort_code = RXKADNOAUTH;
+ break;
+ }
+ trace_rxrpc_abort(0, "SVK",
+ sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
+ abort_code, PTR_ERR(server_key));
+ *_abort_code = abort_code;
+ return -EPROTO;
+ }
ret = -ENOMEM;
response = kzalloc(sizeof(struct rxkad_response), GFP_NOFS);
@@ -1144,8 +1149,8 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
ticket, ticket_len) < 0)
goto protocol_error_free;
- ret = rxkad_decrypt_ticket(conn, skb, ticket, ticket_len, &session_key,
- &expiry, _abort_code);
+ ret = rxkad_decrypt_ticket(conn, server_key, skb, ticket, ticket_len,
+ &session_key, &expiry, _abort_code);
if (ret < 0)
goto temporary_error_free_ticket;
@@ -1224,6 +1229,7 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
protocol_error:
kfree(response);
trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+ key_put(server_key);
*_abort_code = abort_code;
return -EPROTO;
@@ -1236,6 +1242,7 @@ static int rxkad_verify_response(struct rxrpc_connection *conn,
* ENOMEM. We just want to send the challenge again. Note that we
* also come out this way if the ticket decryption fails.
*/
+ key_put(server_key);
return ret;
}
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
index 0c5168f52bd6..bef9971e15cd 100644
--- a/net/rxrpc/security.c
+++ b/net/rxrpc/security.c
@@ -102,22 +102,16 @@ int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
}
/*
- * Find the security key for a server connection.
+ * Set the ops a server connection.
*/
-bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock *rx,
- const struct rxrpc_security **_sec,
- struct key **_key,
- struct sk_buff *skb)
+const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
+ struct sk_buff *skb)
{
const struct rxrpc_security *sec;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
- key_ref_t kref = NULL;
- char kdesc[5 + 1 + 3 + 1];
_enter("");
- sprintf(kdesc, "%u:%u", sp->hdr.serviceId, sp->hdr.securityIndex);
-
sec = rxrpc_security_lookup(sp->hdr.securityIndex);
if (!sec) {
trace_rxrpc_abort(0, "SVS",
@@ -125,35 +119,72 @@ bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock
RX_INVALID_OPERATION, EKEYREJECTED);
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
skb->priority = RX_INVALID_OPERATION;
- return false;
+ return NULL;
}
- if (sp->hdr.securityIndex == RXRPC_SECURITY_NONE)
- goto out;
-
- if (!rx->securities) {
+ if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
+ !rx->securities) {
trace_rxrpc_abort(0, "SVR",
sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_INVALID_OPERATION, EKEYREJECTED);
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
- skb->priority = RX_INVALID_OPERATION;
- return false;
+ skb->priority = sec->no_key_abort;
+ return NULL;
}
+ return sec;
+}
+
+/*
+ * Find the security key for a server connection.
+ */
+struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
+ struct sk_buff *skb,
+ u32 kvno, u32 enctype)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxrpc_sock *rx;
+ struct key *key = ERR_PTR(-EKEYREJECTED);
+ key_ref_t kref = NULL;
+ char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
+ int ret;
+
+ _enter("");
+
+ if (enctype)
+ sprintf(kdesc, "%u:%u:%u:%u",
+ sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
+ else if (kvno)
+ sprintf(kdesc, "%u:%u:%u",
+ sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
+ else
+ sprintf(kdesc, "%u:%u",
+ sp->hdr.serviceId, sp->hdr.securityIndex);
+
+ rcu_read_lock();
+
+ rx = rcu_dereference(conn->params.local->service);
+ if (!rx)
+ goto out;
+
/* look through the service's keyring */
kref = keyring_search(make_key_ref(rx->securities, 1UL),
&key_type_rxrpc_s, kdesc, true);
if (IS_ERR(kref)) {
- trace_rxrpc_abort(0, "SVK",
- sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
- sec->no_key_abort, EKEYREJECTED);
- skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
- skb->priority = sec->no_key_abort;
- return false;
+ key = ERR_CAST(kref);
+ goto out;
+ }
+
+ key = key_ref_to_ptr(kref);
+
+ ret = key_validate(key);
+ if (ret < 0) {
+ key_put(key);
+ key = ERR_PTR(ret);
+ goto out;
}
out:
- *_sec = sec;
- *_key = key_ref_to_ptr(kref);
- return true;
+ rcu_read_unlock();
+ return key;
}
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