[PATCH 16/18] rxrpc: rxgk: Implement the yfs-rxgk security class (GSSAPI)
From: David Howells
Date: Thu Nov 12 2020 - 08:00:36 EST
Implement the basic parts of the yfs-rxgk security class (security index 6)
to support GSSAPI-negotiated security.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---
include/trace/events/rxrpc.h | 4
net/rxrpc/Makefile | 2
net/rxrpc/ar-internal.h | 12
net/rxrpc/rxgk.c | 1063 ++++++++++++++++++++++++++++++++++++++++++
net/rxrpc/rxgk_app.c | 289 +++++++++++
net/rxrpc/rxgk_common.h | 118 +++++
net/rxrpc/security.c | 3
7 files changed, 1491 insertions(+)
create mode 100644 net/rxrpc/rxgk.c
create mode 100644 net/rxrpc/rxgk_app.c
diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index e70c90116eda..dd541c6d5ea3 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -210,6 +210,8 @@ enum rxrpc_tx_point {
rxrpc_tx_point_call_data_nofrag,
rxrpc_tx_point_call_final_resend,
rxrpc_tx_point_conn_abort,
+ rxrpc_tx_point_rxgk_challenge,
+ rxrpc_tx_point_rxgk_response,
rxrpc_tx_point_rxkad_challenge,
rxrpc_tx_point_rxkad_response,
rxrpc_tx_point_reject,
@@ -440,6 +442,8 @@ enum rxrpc_tx_point {
EM(rxrpc_tx_point_call_final_resend, "CallFinalResend") \
EM(rxrpc_tx_point_conn_abort, "ConnAbort") \
EM(rxrpc_tx_point_reject, "Reject") \
+ EM(rxrpc_tx_point_rxgk_challenge, "RxGKChall") \
+ EM(rxrpc_tx_point_rxgk_response, "RxGKResp") \
EM(rxrpc_tx_point_rxkad_challenge, "RxkadChall") \
EM(rxrpc_tx_point_rxkad_response, "RxkadResp") \
EM(rxrpc_tx_point_version_keepalive, "VerKeepalive") \
diff --git a/net/rxrpc/Makefile b/net/rxrpc/Makefile
index 08636858e77f..4be98775dc7f 100644
--- a/net/rxrpc/Makefile
+++ b/net/rxrpc/Makefile
@@ -37,4 +37,6 @@ rxrpc-$(CONFIG_RXKAD) += rxkad.o
rxrpc-$(CONFIG_SYSCTL) += sysctl.o
rxrpc-$(CONFIG_RXGK) += \
+ rxgk.o \
+ rxgk_app.o \
rxgk_kdf.o
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 4e0766b4a714..efdb3334ad88 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -37,6 +37,7 @@ struct rxrpc_crypt {
struct key_preparsed_payload;
struct rxrpc_connection;
+struct rxgk_context;
/*
* Mark applied to socket buffers in skb->mark. skb->priority is used
@@ -264,6 +265,10 @@ struct rxrpc_security {
/* clear connection security */
void (*clear)(struct rxrpc_connection *);
+
+ /* Default ticket -> key decoder */
+ int (*default_decode_ticket)(struct sk_buff *, unsigned int, unsigned int,
+ u32 *, struct key **);
};
/*
@@ -457,7 +462,9 @@ struct rxrpc_connection {
u32 nonce; /* response re-use preventer */
} rxkad;
struct {
+ struct rxgk_context *keys[1];
u64 start_time; /* The start time for TK derivation */
+ u8 nonce[20]; /* Response re-use preventer */
} rxgk;
};
unsigned long flags;
@@ -1056,6 +1063,11 @@ void rxrpc_peer_add_rtt(struct rxrpc_call *, enum rxrpc_rtt_rx_trace, int,
unsigned long rxrpc_get_rto_backoff(struct rxrpc_peer *, bool);
void rxrpc_peer_init_rtt(struct rxrpc_peer *);
+/*
+ * rxgk.c
+ */
+extern const struct rxrpc_security rxgk_yfs;
+
/*
* rxkad.c
*/
diff --git a/net/rxrpc/rxgk.c b/net/rxrpc/rxgk.c
new file mode 100644
index 000000000000..703e46e8b508
--- /dev/null
+++ b/net/rxrpc/rxgk.c
@@ -0,0 +1,1063 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* GSSAPI-based RxRPC security
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/key-type.h>
+#include "ar-internal.h"
+#include "rxgk_common.h"
+
+struct rxgk_header {
+ __be32 epoch;
+ __be32 cid;
+ __be32 call_number;
+ __be32 seq;
+ __be32 sec_index;
+ __be32 data_len;
+} __packed;
+
+struct rxgk_response {
+ __be64 start_time;
+ __be32 token_len;
+} __packed;
+
+/*
+ * Parse the information from a server key
+ */
+static int rxgk_preparse_server_key(struct key_preparsed_payload *prep)
+{
+ const struct krb5_enctype *krb5;
+ struct krb5_buffer *server_key = (void *)&prep->payload.data[2];
+ unsigned int service, sec_class, kvno, enctype;
+ int n = 0;
+
+ _enter("%zu", prep->datalen);
+
+ if (sscanf(prep->orig_description, "%u:%u:%u:%u%n",
+ &service, &sec_class, &kvno, &enctype, &n) != 4)
+ return -EINVAL;
+
+ if (prep->orig_description[n])
+ return -EINVAL;
+
+ krb5 = crypto_krb5_find_enctype(enctype);
+ if (!krb5)
+ return -ENOPKG;
+
+ prep->payload.data[0] = (struct krb5_enctype *)krb5;
+
+ if (prep->datalen != krb5->key_len)
+ return -EKEYREJECTED;
+
+ server_key->len = prep->datalen;
+ server_key->data = kmemdup(prep->data, prep->datalen, GFP_KERNEL);
+ if (!server_key->data)
+ return -ENOMEM;
+
+ _leave(" = 0");
+ return 0;
+}
+
+static void rxgk_free_server_key(union key_payload *payload)
+{
+ struct krb5_buffer *server_key = (void *)&payload->data[2];
+
+ kfree_sensitive(server_key->data);
+}
+
+static void rxgk_free_preparse_server_key(struct key_preparsed_payload *prep)
+{
+ rxgk_free_server_key(&prep->payload);
+}
+
+static void rxgk_destroy_server_key(struct key *key)
+{
+ rxgk_free_server_key(&key->payload);
+}
+
+static void rxgk_describe_server_key(const struct key *key, struct seq_file *m)
+{
+ const struct krb5_enctype *krb5 = key->payload.data[0];
+
+ if (krb5)
+ seq_printf(m, ": %s", krb5->name);
+}
+
+static struct rxgk_context *rxgk_get_key(struct rxrpc_connection *conn,
+ u16 *specific_key_number)
+{
+ refcount_inc(&conn->rxgk.keys[0]->usage);
+ return conn->rxgk.keys[0];
+}
+
+/*
+ * initialise connection security
+ */
+static int rxgk_init_connection_security(struct rxrpc_connection *conn,
+ struct rxrpc_key_token *token)
+{
+ struct rxgk_context *gk;
+ int ret;
+
+ _enter("{%d},{%x}", conn->debug_id, key_serial(conn->params.key));
+
+ conn->security_ix = token->security_index;
+ conn->params.security_level = token->rxgk->level;
+
+ if (rxrpc_conn_is_client(conn)) {
+ conn->rxgk.start_time = ktime_get();
+ do_div(conn->rxgk.start_time, 100);
+ }
+
+ gk = rxgk_generate_transport_key(conn, token->rxgk, 0, GFP_NOFS);
+ if (IS_ERR(gk))
+ return PTR_ERR(gk);
+ conn->rxgk.keys[0] = gk;
+
+ switch (conn->params.security_level) {
+ case RXRPC_SECURITY_PLAIN:
+ break;
+ case RXRPC_SECURITY_AUTH:
+ conn->security_size = gk->krb5->cksum_len;
+ break;
+ case RXRPC_SECURITY_ENCRYPT:
+ if (gk->krb5->pad)
+ conn->size_align = gk->krb5->block_len;
+ conn->security_size = gk->krb5->conf_len + sizeof(struct rxgk_header);
+ conn->security_trailer = gk->krb5->cksum_len;
+ break;
+ default:
+ ret = -EKEYREJECTED;
+ goto error;
+ }
+
+ ret = 0;
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Clean up the crypto on a call.
+ */
+static void rxgk_free_call_crypto(struct rxrpc_call *call)
+{
+}
+
+/*
+ * Integrity mode (sign a packet - level 1 security)
+ */
+static int rxgk_secure_packet_integrity(const struct rxrpc_call *call,
+ struct rxgk_context *gk,
+ struct sk_buff *skb, u32 data_size)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxgk_header *hdr;
+ struct krb5_buffer metadata;
+ int ret = -ENOMEM;
+
+ _enter("");
+
+ hdr = kzalloc(sizeof(*hdr), GFP_NOFS);
+ if (!hdr)
+ goto error_gk;
+
+ hdr->epoch = htonl(call->conn->proto.epoch);
+ hdr->cid = htonl(call->cid);
+ hdr->call_number = htonl(call->call_id);
+ hdr->seq = htonl(sp->hdr.seq);
+ hdr->sec_index = htonl(call->security_ix);
+ hdr->data_len = htonl(data_size);
+
+ metadata.len = sizeof(*hdr);
+ metadata.data = hdr;
+ ret = rxgk_get_mic_skb(gk->krb5, gk->tx_Kc, &metadata, skb,
+ 0, skb->len, gk->krb5->cksum_len, data_size);
+ if (ret >= 0)
+ gk->bytes_remaining -= ret;
+ kfree(hdr);
+error_gk:
+ rxgk_put(gk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * wholly encrypt a packet (level 2 security)
+ */
+static int rxgk_secure_packet_encrypted(const struct rxrpc_call *call,
+ struct rxgk_context *gk,
+ struct sk_buff *skb, u32 data_size)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxgk_header hdr;
+ int ret;
+
+ _enter("%x,%x", skb->len, data_size);
+
+ /* Insert the header into the skb */
+ hdr.epoch = htonl(call->conn->proto.epoch);
+ hdr.cid = htonl(call->cid);
+ hdr.call_number = htonl(call->call_id);
+ hdr.seq = htonl(sp->hdr.seq);
+ hdr.sec_index = htonl(call->security_ix);
+ hdr.data_len = htonl(data_size);
+
+ ret = skb_store_bits(skb, gk->krb5->conf_len, &hdr, sizeof(hdr));
+ if (ret < 0)
+ goto error;
+
+ /* Increase the buffer size to allow for the checksum to be written in */
+ skb->len += gk->krb5->cksum_len;
+
+ ret = rxgk_encrypt_skb(gk->krb5, &gk->tx_enc, skb,
+ 0, skb->len, gk->krb5->conf_len, sizeof(hdr) + data_size,
+ false);
+ if (ret >= 0)
+ gk->bytes_remaining -= ret;
+
+error:
+ rxgk_put(gk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * checksum an RxRPC packet header
+ */
+static int rxgk_secure_packet(struct rxrpc_call *call,
+ struct sk_buff *skb,
+ size_t data_size)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxgk_context *gk;
+ int ret;
+
+ sp = rxrpc_skb(skb);
+
+ _enter("{%d{%x}},{#%u},%zu,",
+ call->debug_id, key_serial(call->conn->params.key),
+ sp->hdr.seq, data_size);
+
+ gk = rxgk_get_key(call->conn, NULL);
+ if (IS_ERR(gk))
+ return PTR_ERR(gk) == -ESTALE ? -EKEYREJECTED : PTR_ERR(gk);
+
+ ret = key_validate(call->conn->params.key);
+ if (ret < 0)
+ return ret;
+
+ sp->hdr.cksum = gk->key_number;
+
+ switch (call->conn->params.security_level) {
+ case RXRPC_SECURITY_PLAIN:
+ rxgk_put(gk);
+ return 0;
+ case RXRPC_SECURITY_AUTH:
+ return rxgk_secure_packet_integrity(call, gk, skb, data_size);
+ case RXRPC_SECURITY_ENCRYPT:
+ return rxgk_secure_packet_encrypted(call, gk, skb, data_size);
+ default:
+ rxgk_put(gk);
+ return -EPERM;
+ }
+}
+
+/*
+ * Integrity mode (check the signature on a packet - level 1 security)
+ */
+static int rxgk_verify_packet_integrity(struct rxrpc_call *call,
+ struct rxgk_context *gk,
+ struct sk_buff *skb,
+ unsigned int offset, unsigned int len,
+ rxrpc_seq_t seq)
+{
+ struct rxgk_header *hdr;
+ struct krb5_buffer metadata;
+ bool aborted;
+ u32 ac;
+ int ret = -ENOMEM;
+
+ _enter("");
+
+ hdr = kzalloc(sizeof(*hdr), GFP_NOFS);
+ if (!hdr)
+ goto error;
+
+ hdr->epoch = htonl(call->conn->proto.epoch);
+ hdr->cid = htonl(call->cid);
+ hdr->call_number = htonl(call->call_id);
+ hdr->seq = htonl(seq);
+ hdr->sec_index = htonl(call->security_ix);
+ hdr->data_len = htonl(len - gk->krb5->cksum_len);
+
+ metadata.len = sizeof(*hdr);
+ metadata.data = hdr;
+ ret = rxgk_verify_mic_skb(gk->krb5, gk->rx_Kc, &metadata,
+ skb, &offset, &len, &ac);
+ kfree(hdr);
+ if (ret < 0) {
+ if (ret == -EPROTO) {
+ aborted = rxrpc_abort_eproto(call, skb, "rxgk_2_vfy",
+ "V1V", ac);
+ goto protocol_error;
+ }
+ goto error;
+ }
+
+error:
+ rxgk_put(gk);
+ _leave(" = %d", ret);
+ return ret;
+
+protocol_error:
+ if (aborted)
+ rxrpc_send_abort_packet(call);
+ ret = -EPROTO;
+ goto error;
+}
+
+/*
+ * Decrypt an encrypted packet (level 2 security).
+ */
+static int rxgk_verify_packet_encrypted(struct rxrpc_call *call,
+ struct rxgk_context *gk,
+ struct sk_buff *skb,
+ unsigned int offset, unsigned int len,
+ rxrpc_seq_t seq)
+{
+ struct rxgk_header hdr;
+ bool aborted;
+ int ret;
+ u32 ac;
+
+ _enter("");
+
+ ret = rxgk_decrypt_skb(gk->krb5, &gk->rx_enc, skb, &offset, &len, &ac);
+ if (ret < 0) {
+ if (ret == -EPROTO) {
+ aborted = rxrpc_abort_eproto(call, skb, "rxgk_2_dec",
+ "V2D", ac);
+ goto protocol_error;
+ }
+ goto error;
+ }
+
+ if (len < sizeof(hdr)) {
+ aborted = rxrpc_abort_eproto(call, skb, "rxgk_2_hdr",
+ "V2L", RXGK_PACKETSHORT);
+ goto protocol_error;
+ }
+
+ /* Extract the header from the skb */
+ ret = skb_copy_bits(skb, offset, &hdr, sizeof(hdr));
+ if (ret < 0)
+ goto error;
+ len -= sizeof(hdr);
+
+ if (ntohl(hdr.epoch) != call->conn->proto.epoch ||
+ ntohl(hdr.cid) != call->cid ||
+ ntohl(hdr.call_number) != call->call_id ||
+ ntohl(hdr.seq) != seq ||
+ ntohl(hdr.sec_index) != call->security_ix ||
+ ntohl(hdr.data_len) > len) {
+ aborted = rxrpc_abort_eproto(call, skb, "rxgk_2_hdr", "V2H",
+ RXGK_SEALED_INCON);
+ goto protocol_error;
+ }
+
+ ret = 0;
+
+error:
+ rxgk_put(gk);
+ _leave(" = %d", ret);
+ return ret;
+
+protocol_error:
+ if (aborted)
+ rxrpc_send_abort_packet(call);
+ ret = -EPROTO;
+ goto error;
+}
+
+/*
+ * Verify the security on a received packet or subpacket (if part of a
+ * jumbo packet).
+ */
+static int rxgk_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
+ unsigned int offset, unsigned int len,
+ rxrpc_seq_t seq, u16 key_number)
+{
+ struct rxgk_context *gk;
+ bool aborted;
+
+ _enter("{%d{%x}},{#%u}",
+ call->debug_id, key_serial(call->conn->params.key), seq);
+
+ gk = rxgk_get_key(call->conn, &key_number);
+ if (IS_ERR(gk)) {
+ switch (PTR_ERR(gk)) {
+ case -ESTALE:
+ aborted = rxrpc_abort_eproto(call, skb, "rxgk_csum", "VKY",
+ RXGK_BADKEYNO);
+ gk = NULL;
+ goto protocol_error;
+ default:
+ return PTR_ERR(gk);
+ }
+ }
+
+ switch (call->conn->params.security_level) {
+ case RXRPC_SECURITY_PLAIN:
+ return 0;
+ case RXRPC_SECURITY_AUTH:
+ return rxgk_verify_packet_integrity(call, gk, skb, offset, len, seq);
+ case RXRPC_SECURITY_ENCRYPT:
+ return rxgk_verify_packet_encrypted(call, gk, skb, offset, len, seq);
+ default:
+ rxgk_put(gk);
+ return -ENOANO;
+ }
+
+protocol_error:
+ if (aborted)
+ rxrpc_send_abort_packet(call);
+ rxgk_put(gk);
+ return -EPROTO;
+}
+
+/*
+ * Locate the data contained in a packet that was partially encrypted.
+ */
+static void rxgk_locate_data_1(struct rxrpc_call *call, struct sk_buff *skb,
+ unsigned int *_offset, unsigned int *_len)
+{
+ *_offset += call->conn->security_size;
+ *_len -= call->conn->security_size;
+}
+
+/*
+ * Locate the data contained in a packet that was completely encrypted.
+ */
+static void rxgk_locate_data_2(struct rxrpc_call *call, struct sk_buff *skb,
+ unsigned int *_offset, unsigned int *_len)
+{
+ unsigned int off = call->conn->security_size - sizeof(__be32);
+ __be32 data_length_be;
+ u32 data_length;
+
+ if (skb_copy_bits(skb, *_offset + off, &data_length_be, sizeof(u32)) < 0)
+ BUG();
+ data_length = ntohl(data_length_be);
+ *_offset += call->conn->security_size;
+ *_len = data_length;
+}
+
+/*
+ * Locate the data contained in an already decrypted packet.
+ */
+static void rxgk_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
+ unsigned int *_offset, unsigned int *_len)
+{
+ switch (call->conn->params.security_level) {
+ case RXRPC_SECURITY_AUTH:
+ rxgk_locate_data_1(call, skb, _offset, _len);
+ return;
+ case RXRPC_SECURITY_ENCRYPT:
+ rxgk_locate_data_2(call, skb, _offset, _len);
+ return;
+ default:
+ return;
+ }
+}
+
+/*
+ * issue a challenge
+ */
+static int rxgk_issue_challenge(struct rxrpc_connection *conn)
+{
+ struct rxrpc_wire_header whdr;
+ struct msghdr msg;
+ struct kvec iov[2];
+ size_t len;
+ u32 serial;
+ int ret;
+
+ _enter("{%d}", conn->debug_id);
+
+ get_random_bytes(&conn->rxgk.nonce, sizeof(conn->rxgk.nonce));
+
+ msg.msg_name = &conn->params.peer->srx.transport;
+ msg.msg_namelen = conn->params.peer->srx.transport_len;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ whdr.epoch = htonl(conn->proto.epoch);
+ whdr.cid = htonl(conn->proto.cid);
+ whdr.callNumber = 0;
+ whdr.seq = 0;
+ whdr.type = RXRPC_PACKET_TYPE_CHALLENGE;
+ whdr.flags = conn->out_clientflag;
+ whdr.userStatus = 0;
+ whdr.securityIndex = conn->security_ix;
+ whdr._rsvd = 0;
+ whdr.serviceId = htons(conn->service_id);
+
+ iov[0].iov_base = &whdr;
+ iov[0].iov_len = sizeof(whdr);
+ iov[1].iov_base = conn->rxgk.nonce;
+ iov[1].iov_len = sizeof(conn->rxgk.nonce);
+
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ serial = atomic_inc_return(&conn->serial);
+ whdr.serial = htonl(serial);
+ _proto("Tx CHALLENGE %%%u", serial);
+
+ ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+ if (ret < 0) {
+ trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+ rxrpc_tx_point_rxgk_challenge);
+ return -EAGAIN;
+ }
+
+ conn->params.peer->last_tx_at = ktime_get_seconds();
+ trace_rxrpc_tx_packet(conn->debug_id, &whdr,
+ rxrpc_tx_point_rxgk_challenge);
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * Send a response packet.
+ */
+static int rxgk_send_response(struct rxrpc_connection *conn,
+ struct sk_buff *skb)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct rxrpc_wire_header whdr;
+ struct msghdr msg;
+ struct kvec iov[2];
+ size_t len;
+ u32 serial;
+ int ret, i;
+
+ _enter("");
+
+ msg.msg_name = &conn->params.peer->srx.transport;
+ msg.msg_namelen = conn->params.peer->srx.transport_len;
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_flags = 0;
+
+ memset(&whdr, 0, sizeof(whdr));
+ whdr.epoch = htonl(sp->hdr.epoch);
+ whdr.cid = htonl(sp->hdr.cid);
+ whdr.type = RXRPC_PACKET_TYPE_RESPONSE;
+ whdr.flags = sp->hdr.flags;
+ whdr.securityIndex = sp->hdr.securityIndex;
+ whdr.cksum = htons(sp->hdr.cksum);
+ whdr.serviceId = htons(sp->hdr.serviceId);
+
+ iov[0].iov_base = &whdr;
+ iov[0].iov_len = sizeof(whdr);
+ iov[1].iov_base = skb->head;
+ iov[1].iov_len = skb->len;
+
+ len = 0;
+ for (i = 0; i < ARRAY_SIZE(iov); i++)
+ len += iov[i].iov_len;
+
+ serial = atomic_inc_return(&conn->serial);
+ whdr.serial = htonl(serial);
+ _proto("Tx RESPONSE %%%u", serial);
+
+ ret = kernel_sendmsg(conn->params.local->socket, &msg,
+ iov, ARRAY_SIZE(iov), len);
+ if (ret < 0) {
+ trace_rxrpc_tx_fail(conn->debug_id, serial, ret,
+ rxrpc_tx_point_rxgk_response);
+ return -EAGAIN;
+ }
+
+ conn->params.peer->last_tx_at = ktime_get_seconds();
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * Construct the authenticator to go in the response packet
+ *
+ * struct RXGK_Authenticator {
+ * opaque nonce[20];
+ * opaque appdata<>;
+ * RXGK_Level level;
+ * unsigned int epoch;
+ * unsigned int cid;
+ * unsigned int call_numbers<>;
+ * };
+ */
+static void rxgk_construct_authenticator(struct rxrpc_connection *conn,
+ const u8 *nonce,
+ struct sk_buff *skb)
+{
+ __be32 xdr[9];
+
+ __skb_put_data(skb, nonce, 20);
+
+ xdr[0] = htonl(0); /* appdata len */
+ xdr[1] = htonl(conn->params.security_level);
+ xdr[2] = htonl(conn->proto.epoch);
+ xdr[3] = htonl(conn->proto.cid);
+ xdr[4] = htonl(4); /* # call_numbers */
+ xdr[5] = htonl(conn->channels[0].call_counter);
+ xdr[6] = htonl(conn->channels[1].call_counter);
+ xdr[7] = htonl(conn->channels[2].call_counter);
+ xdr[8] = htonl(conn->channels[3].call_counter);
+
+ __skb_put_data(skb, xdr, sizeof(xdr));
+}
+
+/*
+ * Construct the response.
+ *
+ * struct RXGK_Response {
+ * rxgkTime start_time;
+ * RXGK_Data token;
+ * opaque authenticator<RXGK_MAXAUTHENTICATOR>
+ * };
+ */
+static int rxgk_construct_response(struct rxrpc_connection *conn,
+ struct sk_buff *challenge,
+ const u8 *nonce)
+{
+ struct rxrpc_skb_priv *csp = rxrpc_skb(challenge), *rsp;
+ struct rxgk_context *gk;
+ struct sk_buff *skb;
+ unsigned short resp_len, auth_len, pad_len, enc_len, auth_pad_len, authx_len;
+ unsigned short auth_offset, authx_offset;
+ __be64 start_time;
+ __be32 tmp;
+ void *p;
+ int ret;
+
+ gk = rxgk_get_key(conn, NULL);
+ if (IS_ERR(gk))
+ return PTR_ERR(gk);
+
+ auth_len = 20 + 4 /* appdatalen */ + 12 + (1 + 4) * 4;
+ if (gk->krb5->pad) {
+ enc_len = round_up(gk->krb5->conf_len + auth_len, gk->krb5->block_len);
+ pad_len = enc_len - (gk->krb5->conf_len + auth_len);
+ } else {
+ enc_len = gk->krb5->conf_len + auth_len;
+ pad_len = 0;
+ }
+ authx_len = enc_len + gk->krb5->cksum_len;
+ auth_pad_len = xdr_round_up(authx_len) - authx_len;
+
+ resp_len = 8;
+ resp_len += 4 + xdr_round_up(gk->key->ticket.len);
+ resp_len += 4 + xdr_round_up(authx_len);
+
+ ret = -ENOMEM;
+ skb = alloc_skb(resp_len, GFP_NOFS);
+ if (!skb)
+ goto error_gk;
+
+ rsp = rxrpc_skb(skb);
+ rsp->hdr = csp->hdr;
+ rsp->hdr.flags = conn->out_clientflag;
+ rsp->hdr.cksum = gk->key_number;
+
+ start_time = cpu_to_be64(conn->rxgk.start_time);
+ p = __skb_put_data(skb, &start_time, 8);
+
+ tmp = htonl(gk->key->ticket.len);
+ __skb_put_data(skb, &tmp, 4);
+ __skb_put_data(skb, gk->key->ticket.data, xdr_round_up(gk->key->ticket.len));
+ tmp = htonl(authx_len);
+ __skb_put_data(skb, &tmp, 4);
+ authx_offset = skb->len;
+ __skb_put_zero(skb, gk->krb5->conf_len);
+ auth_offset = skb->len;
+ rxgk_construct_authenticator(conn, nonce, skb);
+ __skb_put_zero(skb, pad_len + gk->krb5->cksum_len + auth_pad_len);
+
+ ret = rxgk_encrypt_skb(gk->krb5, &gk->resp_enc, skb,
+ authx_offset, authx_len,
+ auth_offset, auth_len, false);
+ if (ret < 0)
+ goto error;
+
+ ret = rxgk_send_response(conn, skb);
+error:
+ kfree_skb(skb);
+error_gk:
+ rxgk_put(gk);
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Respond to a challenge packet
+ */
+static int rxgk_respond_to_challenge(struct rxrpc_connection *conn,
+ struct sk_buff *skb,
+ u32 *_abort_code)
+{
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ const char *eproto;
+ u32 abort_code;
+ u8 nonce[20];
+ int ret;
+
+ _enter("{%d,%x}", conn->debug_id, key_serial(conn->params.key));
+
+ eproto = tracepoint_string("chall_no_key");
+ abort_code = RX_PROTOCOL_ERROR;
+ if (!conn->params.key)
+ goto protocol_error;
+
+ abort_code = RXGK_EXPIRED;
+ ret = key_validate(conn->params.key);
+ if (ret < 0)
+ goto other_error;
+
+ eproto = tracepoint_string("chall_short");
+ abort_code = RXGK_PACKETSHORT;
+ if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+ nonce, sizeof(nonce)) < 0)
+ goto protocol_error;
+
+ _proto("Rx CHALLENGE %%%u { n=%20phN }", sp->hdr.serial, nonce);
+
+ ret = rxgk_construct_response(conn, skb, nonce);
+ if (ret < 0)
+ goto error;
+ return ret;
+
+protocol_error:
+ trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+ ret = -EPROTO;
+other_error:
+ *_abort_code = abort_code;
+error:
+ return ret;
+}
+
+/*
+ * Verify the authenticator.
+ *
+ * struct RXGK_Authenticator {
+ * opaque nonce[20];
+ * opaque appdata<>;
+ * RXGK_Level level;
+ * unsigned int epoch;
+ * unsigned int cid;
+ * unsigned int call_numbers<>;
+ * };
+ */
+static int rxgk_verify_authenticator(struct rxrpc_connection *conn,
+ const struct krb5_enctype *krb5,
+ struct sk_buff *skb,
+ unsigned int auth_offset, unsigned int auth_len,
+ u32 *_abort_code, const char **_eproto)
+{
+ void *auth;
+ __be32 *p, *end;
+ u32 app_len, call_count, level, epoch, cid, i;
+ int ret;
+
+ _enter("");
+
+ auth = kmalloc(auth_len, GFP_NOFS);
+ if (!auth)
+ return -ENOMEM;
+
+ ret = skb_copy_bits(skb, auth_offset, auth, auth_len);
+ if (ret < 0)
+ goto error;
+
+ *_eproto = tracepoint_string("rxgk_rsp_nonce");
+ p = auth;
+ end = auth + auth_len;
+ if (memcmp(auth, conn->rxgk.nonce, 20) != 0)
+ goto bad_auth;
+ p += 20 / sizeof(__be32);
+
+ *_eproto = tracepoint_string("rxgk_rsp_applen");
+ app_len = ntohl(*p++);
+ if (app_len > (end - p) * sizeof(__be32))
+ goto bad_auth;
+ p += xdr_round_up(app_len) / sizeof(__be32);
+ if (end - p < 4)
+ goto bad_auth;
+ level = ntohl(*p++);
+ epoch = ntohl(*p++);
+ cid = ntohl(*p++);
+ call_count = ntohl(*p++);
+
+ *_eproto = tracepoint_string("rxgk_rsp_params");
+ if (level != conn->params.security_level ||
+ epoch != conn->proto.epoch ||
+ cid != conn->proto.cid ||
+ call_count > 4)
+ goto bad_auth;
+ if (end - p < call_count)
+ goto bad_auth;
+
+ spin_lock(&conn->bundle->channel_lock);
+ for (i = 0; i < call_count; i++) {
+ struct rxrpc_call *call;
+ u32 call_id = ntohl(*p++);
+
+ *_eproto = tracepoint_string("rxgk_rsp_callid");
+ if (call_id > INT_MAX)
+ goto bad_auth_unlock;
+
+ *_eproto = tracepoint_string("rxgk_rsp_callctr");
+ if (call_id < conn->channels[i].call_counter)
+ goto bad_auth_unlock;
+
+ *_eproto = tracepoint_string("rxgk_rsp_callst");
+ if (call_id > conn->channels[i].call_counter) {
+ call = rcu_dereference_protected(
+ conn->channels[i].call,
+ lockdep_is_held(&conn->bundle->channel_lock));
+ if (call && call->state < RXRPC_CALL_COMPLETE)
+ goto bad_auth_unlock;
+ conn->channels[i].call_counter = call_id;
+ }
+ }
+ spin_unlock(&conn->bundle->channel_lock);
+ ret = 0;
+error:
+ kfree(auth);
+ _leave(" = %d", ret);
+ return ret;
+
+bad_auth_unlock:
+ spin_unlock(&conn->bundle->channel_lock);
+bad_auth:
+ *_abort_code = RXGK_NOTAUTH;
+ ret = -EPROTO;
+ goto error;
+}
+
+/*
+ * Verify a response.
+ *
+ * struct RXGK_Response {
+ * rxgkTime start_time;
+ * RXGK_Data token;
+ * opaque authenticator<RXGK_MAXAUTHENTICATOR>
+ * };
+ */
+static int rxgk_verify_response(struct rxrpc_connection *conn,
+ struct sk_buff *skb,
+ u32 *_abort_code)
+{
+ const struct krb5_enctype *krb5;
+ struct rxrpc_key_token *token;
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
+ struct krb5_enc_keys token_enc = {};
+ struct rxgk_context *gk;
+ struct key *key = NULL;
+ const char *eproto;
+ unsigned int offset = sizeof(struct rxrpc_wire_header);
+ unsigned int len = skb->len - sizeof(struct rxrpc_wire_header);
+ unsigned int token_offset, token_len;
+ unsigned int auth_offset, auth_len;
+ __be32 xauth_len;
+ u32 abort_code;
+ int ret;
+
+ struct rxgk_response rhdr;
+
+ _enter("{%d}", conn->debug_id);
+
+ /* Parse the RXGK_Response object */
+ if (sizeof(rhdr) + sizeof(__be32) > len)
+ goto short_packet;
+
+ if (skb_copy_bits(skb, offset, &rhdr, sizeof(rhdr)) < 0)
+ goto short_packet;
+ offset += sizeof(rhdr);
+ len -= sizeof(rhdr);
+
+ token_offset = offset;
+ token_len = ntohl(rhdr.token_len);
+ if (xdr_round_up(token_len) + sizeof(__be32) > len)
+ goto short_packet;
+
+ offset += xdr_round_up(token_len);
+ len -= xdr_round_up(token_len);
+
+ if (skb_copy_bits(skb, offset, &xauth_len, sizeof(xauth_len)) < 0)
+ goto short_packet;
+ offset += sizeof(xauth_len);
+ len -= sizeof(xauth_len);
+
+ auth_offset = offset;
+ auth_len = ntohl(xauth_len);
+ if (auth_len < len)
+ goto short_packet;
+ if (auth_len & 3)
+ goto inconsistent;
+ if (auth_len < 20 + 9 * 4)
+ goto auth_too_short;
+
+ /* We need to extract and decrypt the token and instantiate a session
+ * key for it. This bit, however, is application-specific. If
+ * possible, we use a default parser, but we might end up bumping this
+ * to the app to deal with - which might mean a round trip to
+ * userspace.
+ */
+ ret = rxgk_extract_token(conn, skb, token_offset, token_len, &key,
+ &abort_code, &eproto);
+ if (ret < 0)
+ goto protocol_error;
+
+ /* We now have a key instantiated from the decrypted ticket. We can
+ * pass this to the application so that they can parse the ticket
+ * content and we can use the session key it contains to derive the
+ * keys we need.
+ *
+ * Note that we have to switch enctype at this point as the enctype of
+ * the ticket doesn't necessarily match that of the transport.
+ */
+ token = key->payload.data[0];
+ conn->params.security_level = token->rxgk->level;
+ conn->rxgk.start_time = __be64_to_cpu(rhdr.start_time);
+
+ gk = rxgk_generate_transport_key(conn, token->rxgk, sp->hdr.cksum, GFP_NOFS);
+ if (IS_ERR(gk)) {
+ ret = PTR_ERR(gk);
+ goto cant_get_token;
+ }
+
+ krb5 = gk->krb5;
+
+ /* Decrypt, parse and verify the authenticator. */
+ eproto = tracepoint_string("rxgk_rsp_dec_auth");
+ ret = rxgk_decrypt_skb(krb5, &gk->resp_enc, skb,
+ &auth_offset, &auth_len, &abort_code);
+ if (ret < 0)
+ goto protocol_error;
+
+ ret = rxgk_verify_authenticator(conn, krb5, skb, auth_offset, auth_len,
+ &abort_code, &eproto);
+ if (ret < 0)
+ goto protocol_error;
+
+ conn->params.key = key;
+ key = NULL;
+ ret = 0;
+out:
+ key_put(key);
+ crypto_krb5_free_enc_keys(&token_enc);
+ _leave(" = %d", ret);
+ return ret;
+
+inconsistent:
+ eproto = tracepoint_string("rxgk_rsp_xdr_align");
+ abort_code = RXGK_INCONSISTENCY;
+ ret = -EPROTO;
+ goto protocol_error;
+auth_too_short:
+ eproto = tracepoint_string("rxgk_rsp_short_auth");
+ abort_code = RXGK_PACKETSHORT;
+ ret = -EPROTO;
+ goto protocol_error;
+short_packet:
+ eproto = tracepoint_string("rxgk_rsp_short");
+ abort_code = RXGK_PACKETSHORT;
+ ret = -EPROTO;
+protocol_error:
+ trace_rxrpc_rx_eproto(NULL, sp->hdr.serial, eproto);
+ *_abort_code = abort_code;
+ goto out;
+
+cant_get_token:
+ switch (ret) {
+ case -ENOMEM:
+ goto temporary_error;
+ case -EINVAL:
+ eproto = tracepoint_string("rxgk_rsp_internal_error");
+ abort_code = RXGK_NOTAUTH;
+ ret = -EKEYREJECTED;
+ goto protocol_error;
+ case -ENOPKG:
+ eproto = tracepoint_string("rxgk_rsp_nopkg");
+ abort_code = RXGK_BADETYPE;
+ ret = -EKEYREJECTED;
+ goto protocol_error;
+ }
+
+temporary_error:
+ /* Ignore the response packet if we got a temporary error such as
+ * ENOMEM. We just want to send the challenge again. Note that we
+ * also come out this way if the ticket decryption fails.
+ */
+ goto out;
+}
+
+/*
+ * clear the connection security
+ */
+static void rxgk_clear(struct rxrpc_connection *conn)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(conn->rxgk.keys); i++)
+ rxgk_put(conn->rxgk.keys[i]);
+}
+
+/*
+ * Initialise the RxGK security service.
+ */
+static int rxgk_init(void)
+{
+ return 0;
+}
+
+/*
+ * Clean up the RxGK security service.
+ */
+static void rxgk_exit(void)
+{
+}
+
+/*
+ * RxRPC YFS GSSAPI-based security
+ */
+const struct rxrpc_security rxgk_yfs = {
+ .name = "yfs-rxgk",
+ .security_index = RXRPC_SECURITY_YFS_RXGK,
+ .no_key_abort = RXGK_NOTAUTH,
+ .init = rxgk_init,
+ .exit = rxgk_exit,
+ .preparse_server_key = rxgk_preparse_server_key,
+ .free_preparse_server_key = rxgk_free_preparse_server_key,
+ .destroy_server_key = rxgk_destroy_server_key,
+ .describe_server_key = rxgk_describe_server_key,
+ .init_connection_security = rxgk_init_connection_security,
+ .secure_packet = rxgk_secure_packet,
+ .verify_packet = rxgk_verify_packet,
+ .free_call_crypto = rxgk_free_call_crypto,
+ .locate_data = rxgk_locate_data,
+ .issue_challenge = rxgk_issue_challenge,
+ .respond_to_challenge = rxgk_respond_to_challenge,
+ .verify_response = rxgk_verify_response,
+ .clear = rxgk_clear,
+ .default_decode_ticket = rxgk_yfs_decode_ticket,
+};
diff --git a/net/rxrpc/rxgk_app.c b/net/rxrpc/rxgk_app.c
new file mode 100644
index 000000000000..895879f3acfb
--- /dev/null
+++ b/net/rxrpc/rxgk_app.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Application-specific bits for GSSAPI-based RxRPC security
+ *
+ * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@xxxxxxxxxx)
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/key-type.h>
+#include "ar-internal.h"
+#include "rxgk_common.h"
+
+/*
+ * Decode a default-style YFS ticket in a response and turn it into an
+ * rxrpc-type key.
+ *
+ * struct rxgk_key {
+ * afs_uint32 enctype;
+ * opaque key<>;
+ * };
+ *
+ * struct RXGK_AuthName {
+ * afs_int32 kind;
+ * opaque data<AUTHDATAMAX>;
+ * opaque display<AUTHPRINTABLEMAX>;
+ * };
+ *
+ * struct RXGK_Token {
+ * rxgk_key K0;
+ * RXGK_Level level;
+ * rxgkTime starttime;
+ * afs_int32 lifetime;
+ * afs_int32 bytelife;
+ * rxgkTime expirationtime;
+ * struct RXGK_AuthName identities<>;
+ * };
+ */
+int rxgk_yfs_decode_ticket(struct sk_buff *skb,
+ unsigned int ticket_offset, unsigned int ticket_len,
+ u32 *_abort_code,
+ struct key **_key)
+{
+ struct rxrpc_key_token *token;
+ const struct cred *cred = current_cred(); // TODO - use socket creds
+ struct key *key;
+ size_t pre_ticket_len, payload_len;
+ unsigned int klen, enctype;
+ void *payload, *ticket;
+ __be32 *t, *p, *q, tmp[2];
+ int ret;
+
+ _enter("");
+
+ /* Get the session key length */
+ ret = skb_copy_bits(skb, ticket_offset, tmp, sizeof(tmp));
+ if (ret < 0)
+ goto error_out;
+ enctype = ntohl(tmp[0]);
+ klen = ntohl(tmp[1]);
+
+ if (klen > ticket_len - 10 * sizeof(__be32)) {
+ *_abort_code = RXGK_INCONSISTENCY;
+ return -EPROTO;
+ }
+
+ pre_ticket_len = ((5 + 14) * sizeof(__be32) +
+ xdr_round_up(klen) +
+ sizeof(__be32));
+ payload_len = pre_ticket_len + xdr_round_up(ticket_len);
+
+ payload = kzalloc(payload_len, GFP_NOFS);
+ if (!payload)
+ return -ENOMEM;
+
+ /* We need to fill out the XDR form for a key payload that we can pass
+ * to add_key(). Start by copying in the ticket so that we can parse
+ * it.
+ */
+ ticket = payload + pre_ticket_len;
+ ret = skb_copy_bits(skb, ticket_offset, ticket, ticket_len);
+ if (ret < 0)
+ goto error;
+
+ /* Fill out the form header. */
+ p = payload;
+ p[0] = htonl(0); /* Flags */
+ p[1] = htonl(1); /* len(cellname) */
+ p[2] = htonl(0x20000000); /* Cellname " " */
+ p[3] = htonl(1); /* #tokens */
+ p[4] = htonl(15 * sizeof(__be32) + xdr_round_up(klen) + xdr_round_up(ticket_len)); /* Token len */
+
+ /* Now fill in the body. Most of this we can just scrape directly from
+ * the ticket.
+ */
+ t = ticket + sizeof(__be32) * 2 + xdr_round_up(klen);
+ q = payload + 5 * sizeof(__be32);
+ q[ 0] = htonl(RXRPC_SECURITY_YFS_RXGK);
+ q[ 1] = t[1]; /* begintime - msw */
+ q[ 2] = t[2]; /* - lsw */
+ q[ 3] = t[5]; /* endtime - msw */
+ q[ 4] = t[6]; /* - lsw */
+ q[ 5] = 0; /* level - msw */
+ q[ 6] = t[0]; /* - lsw */
+ q[ 7] = 0; /* lifetime - msw */
+ q[ 8] = t[3]; /* - lsw */
+ q[ 9] = 0; /* bytelife - msw */
+ q[10] = t[4]; /* - lsw */
+ q[11] = 0; /* enctype - msw */
+ q[12] = htonl(enctype); /* - lsw */
+ q[13] = htonl(klen); /* Key length */
+
+ q += 14;
+
+ memcpy(q, ticket + sizeof(__be32) * 2, klen);
+ q += xdr_round_up(klen) / 4;
+ q[0] = ntohl(ticket_len);
+ q++;
+ if (WARN_ON((unsigned long)q != (unsigned long)ticket)) {
+ ret = -EIO;
+ goto error;
+ }
+
+ /* Ticket read in with skb_copy_bits above */
+ q += xdr_round_up(ticket_len) / 4;
+ if (WARN_ON((unsigned long)q - (unsigned long)payload != payload_len)) {
+ ret = -EIO;
+ goto error;
+ }
+
+ /* Now turn that into a key. */
+ key = key_alloc(&key_type_rxrpc, "x",
+ GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, 0, // TODO: Use socket owner
+ KEY_ALLOC_NOT_IN_QUOTA, NULL);
+ if (IS_ERR(key)) {
+ _leave(" = -ENOMEM [alloc %ld]", PTR_ERR(key));
+ goto error;
+ }
+
+ _debug("key %d", key_serial(key));
+
+ ret = key_instantiate_and_link(key, payload, payload_len, NULL, NULL);
+ if (ret < 0)
+ goto error_key;
+
+ token = key->payload.data[0];
+ token->no_leak_key = true;
+ *_key = key;
+ key = NULL;
+ ret = 0;
+ goto error;
+
+error_key:
+ key_put(key);
+error:
+ kfree_sensitive(payload);
+error_out:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+/*
+ * Extract the token and set up a session key from the details.
+ *
+ * struct RXGK_TokenContainer {
+ * afs_int32 kvno;
+ * afs_int32 enctype;
+ * opaque encrypted_token<>;
+ * };
+ *
+ * [tools.ietf.org/html/draft-wilkinson-afs3-rxgk-afs-08 sec 6.1]
+ */
+int rxgk_extract_token(struct rxrpc_connection *conn,
+ struct sk_buff *skb,
+ unsigned int token_offset, unsigned int token_len,
+ struct key **_key,
+ u32 *_abort_code, const char **_eproto)
+{
+ const struct krb5_enctype *krb5;
+ const struct krb5_buffer *server_secret;
+ struct krb5_enc_keys token_enc = {};
+ struct key *server_key;
+ unsigned int ticket_offset, ticket_len;
+ u32 kvno, enctype;
+ int ret;
+
+ struct {
+ __be32 kvno;
+ __be32 enctype;
+ __be32 token_len;
+ } container;
+
+ /* Decode the RXGK_TokenContainer object. This tells us which server
+ * key we should be using. We can then fetch the key, get the secret
+ * and set up the crypto to extract the token.
+ */
+ if (skb_copy_bits(skb, token_offset, &container, sizeof(container)) < 0)
+ goto short_packet;
+
+ kvno = ntohl(container.kvno);
+ enctype = ntohl(container.enctype);
+ ticket_len = ntohl(container.token_len);
+ ticket_offset = token_offset + sizeof(container);
+
+ if (xdr_round_up(ticket_len) > token_len - 3 * 4)
+ goto short_packet;
+
+ _debug("KVNO %u", kvno);
+ _debug("ENC %u", enctype);
+ _debug("TLEN %u", ticket_len);
+
+ server_key = rxrpc_look_up_server_security(conn, skb, kvno, enctype);
+ if (IS_ERR(server_key))
+ goto cant_get_server_key;
+
+ down_read(&server_key->sem);
+ server_secret = (const void *)&server_key->payload.data[2];
+ ret = rxgk_set_up_token_cipher(server_secret, &token_enc, enctype, &krb5, GFP_NOFS);
+ up_read(&server_key->sem);
+ key_put(server_key);
+ if (ret < 0)
+ goto cant_get_token;
+
+ /* We can now decrypt and parse the token/ticket. This allows us to
+ * gain access to K0, from which we can derive the transport key and
+ * thence decode the authenticator.
+ */
+ *_eproto = tracepoint_string("rxgk_rsp_dec_tkt");
+ ret = rxgk_decrypt_skb(krb5, &token_enc, skb,
+ &ticket_offset, &ticket_len, _abort_code);
+ if (ret < 0)
+ return ret;
+
+ ret = conn->security->default_decode_ticket(skb, ticket_offset, ticket_len,
+ _abort_code, _key);
+ if (ret < 0)
+ goto cant_get_token;
+
+ _leave(" = 0");
+ return ret;
+
+short_packet:
+ *_eproto = tracepoint_string("rxgk_rsp_short");
+ *_abort_code = RXGK_PACKETSHORT;
+ return -EPROTO;
+
+cant_get_server_key:
+ ret = PTR_ERR(server_key);
+ switch (ret) {
+ case -ENOMEM:
+ goto temporary_error;
+ case -ENOKEY:
+ case -EKEYREJECTED:
+ case -EKEYEXPIRED:
+ case -EKEYREVOKED:
+ case -EPERM:
+ *_eproto = tracepoint_string("rxgk_rsp_nokey");
+ *_abort_code = RXGK_BADKEYNO;
+ return -EKEYREJECTED;
+ default:
+ *_eproto = tracepoint_string("rxgk_rsp_keyerr");
+ *_abort_code = RXGK_NOTAUTH;
+ return -EKEYREJECTED;
+ }
+
+cant_get_token:
+ switch (ret) {
+ case -ENOMEM:
+ goto temporary_error;
+ case -EINVAL:
+ *_eproto = tracepoint_string("rxgk_rsp_internal_error");
+ *_abort_code = RXGK_NOTAUTH;
+ return -EKEYREJECTED;
+ case -ENOPKG:
+ *_eproto = tracepoint_string("rxgk_rsp_nopkg");
+ *_abort_code = RXGK_BADETYPE;
+ return -EKEYREJECTED;
+ }
+
+temporary_error:
+ /* Ignore the response packet if we got a temporary error such as
+ * ENOMEM. We just want to send the challenge again. Note that we
+ * also come out this way if the ticket decryption fails.
+ */
+ return ret;
+}
diff --git a/net/rxrpc/rxgk_common.h b/net/rxrpc/rxgk_common.h
index 3047ad531877..38473b13e67d 100644
--- a/net/rxrpc/rxgk_common.h
+++ b/net/rxrpc/rxgk_common.h
@@ -33,6 +33,17 @@ struct rxgk_context {
struct krb5_enc_keys resp_enc; /* Response packet enc key */
};
+#define xdr_round_up(x) (round_up((x), sizeof(__be32)))
+
+/*
+ * rxgk_app.c
+ */
+int rxgk_yfs_decode_ticket(struct sk_buff *, unsigned int, unsigned int,
+ u32 *, struct key **);
+int rxgk_extract_token(struct rxrpc_connection *,
+ struct sk_buff *, unsigned int, unsigned int,
+ struct key **, u32 *, const char **);
+
/*
* rxgk_kdf.c
*/
@@ -42,3 +53,110 @@ int rxgk_set_up_token_cipher(const struct krb5_buffer *, struct krb5_enc_keys *,
unsigned int, const struct krb5_enctype **,
gfp_t);
void rxgk_put(struct rxgk_context *);
+
+/*
+ * Apply encryption and checksumming functions to part of an skbuff.
+ */
+static inline
+int rxgk_encrypt_skb(const struct krb5_enctype *krb5,
+ struct krb5_enc_keys *keys,
+ struct sk_buff *skb,
+ u16 secure_offset, u16 secure_len,
+ u16 data_offset, u16 data_len,
+ bool preconfounded)
+{
+ struct scatterlist sg[16];
+ int nr_sg;
+
+ sg_init_table(sg, ARRAY_SIZE(sg));
+ nr_sg = skb_to_sgvec(skb, sg, secure_offset, secure_len);
+ if (unlikely(nr_sg < 0))
+ return nr_sg;
+
+ data_offset -= secure_offset;
+ return crypto_krb5_encrypt(krb5, keys, sg, nr_sg, secure_len,
+ data_offset, data_len, preconfounded);
+}
+
+/*
+ * Apply decryption and checksumming functions to part of an skbuff. The
+ * offset and length are updated to reflect the actual content of the encrypted
+ * region.
+ */
+static inline
+int rxgk_decrypt_skb(const struct krb5_enctype *krb5,
+ struct krb5_enc_keys *keys,
+ struct sk_buff *skb,
+ unsigned int *_offset, unsigned int *_len,
+ int *_error_code)
+{
+ struct scatterlist sg[16];
+ size_t offset = 0, len = *_len;
+ int nr_sg, ret;
+
+ sg_init_table(sg, ARRAY_SIZE(sg));
+ nr_sg = skb_to_sgvec(skb, sg, *_offset, len);
+ if (unlikely(nr_sg < 0))
+ return nr_sg;
+
+ ret = crypto_krb5_decrypt(krb5, keys, sg, nr_sg,
+ &offset, &len, _error_code);
+
+ *_offset += offset;
+ *_len = len;
+ return ret;
+}
+
+/*
+ * Generate a checksum over some metadata and part of an skbuff and insert the
+ * MIC into the skbuff immediately prior to the data.
+ */
+static inline
+int rxgk_get_mic_skb(const struct krb5_enctype *krb5,
+ struct crypto_shash *shash,
+ const struct krb5_buffer *metadata,
+ struct sk_buff *skb,
+ u16 secure_offset, u16 secure_len,
+ u16 data_offset, u16 data_len)
+{
+ struct scatterlist sg[16];
+ int nr_sg;
+
+ sg_init_table(sg, ARRAY_SIZE(sg));
+ nr_sg = skb_to_sgvec(skb, sg, secure_offset, secure_len);
+ if (unlikely(nr_sg < 0))
+ return nr_sg;
+
+ data_offset -= secure_offset;
+ return crypto_krb5_get_mic(krb5, shash, metadata, sg, nr_sg, secure_len,
+ data_offset, data_len);
+}
+
+/*
+ * Check the MIC on a region of an skbuff. The offset and length are updated
+ * to reflect the actual content of the secure region.
+ */
+static inline
+int rxgk_verify_mic_skb(const struct krb5_enctype *krb5,
+ struct crypto_shash *shash,
+ const struct krb5_buffer *metadata,
+ struct sk_buff *skb,
+ unsigned int *_offset, unsigned int *_len,
+ u32 *_error_code)
+{
+ struct scatterlist sg[16];
+ size_t offset = 0, len = *_len;
+ int nr_sg, ret;
+
+ sg_init_table(sg, ARRAY_SIZE(sg));
+ nr_sg = skb_to_sgvec(skb, sg, *_offset, len);
+ if (unlikely(nr_sg < 0))
+ return nr_sg;
+
+ ret = crypto_krb5_verify_mic(krb5, shash, metadata, sg, nr_sg,
+ &offset, &len, _error_code);
+
+ *_offset += offset;
+ *_len = len;
+ return 0;
+}
diff --git a/net/rxrpc/security.c b/net/rxrpc/security.c
index 50cb5f1ee0c0..278a510b2956 100644
--- a/net/rxrpc/security.c
+++ b/net/rxrpc/security.c
@@ -20,6 +20,9 @@ static const struct rxrpc_security *rxrpc_security_types[] = {
#ifdef CONFIG_RXKAD
[RXRPC_SECURITY_RXKAD] = &rxkad,
#endif
+#ifdef CONFIG_RXGK
+ [RXRPC_SECURITY_YFS_RXGK] = &rxgk_yfs,
+#endif
};
int __init rxrpc_init_security(void)