diff options
Diffstat (limited to 'net/handshake/tlshd.c')
| -rw-r--r-- | net/handshake/tlshd.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/net/handshake/tlshd.c b/net/handshake/tlshd.c new file mode 100644 index 000000000..bbfb4095d --- /dev/null +++ b/net/handshake/tlshd.c @@ -0,0 +1,449 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Establish a TLS session for a kernel socket consumer + * using the tlshd user space handler. + * + * Author: Chuck Lever <chuck.lever@oracle.com> + * + * Copyright (c) 2021-2023, Oracle and/or its affiliates. + */ + +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/key.h> + +#include <net/sock.h> +#include <net/handshake.h> +#include <net/genetlink.h> +#include <net/tls_prot.h> + +#include <uapi/linux/keyctl.h> +#include <uapi/linux/handshake.h> +#include "handshake.h" + +struct tls_handshake_req { + void (*th_consumer_done)(void *data, int status, + key_serial_t peerid); + void *th_consumer_data; + + int th_type; + unsigned int th_timeout_ms; + int th_auth_mode; + const char *th_peername; + key_serial_t th_keyring; + key_serial_t th_certificate; + key_serial_t th_privkey; + + unsigned int th_num_peerids; + key_serial_t th_peerid[5]; +}; + +static struct tls_handshake_req * +tls_handshake_req_init(struct handshake_req *req, + const struct tls_handshake_args *args) +{ + struct tls_handshake_req *treq = handshake_req_private(req); + + treq->th_timeout_ms = args->ta_timeout_ms; + treq->th_consumer_done = args->ta_done; + treq->th_consumer_data = args->ta_data; + treq->th_peername = args->ta_peername; + treq->th_keyring = args->ta_keyring; + treq->th_num_peerids = 0; + treq->th_certificate = TLS_NO_CERT; + treq->th_privkey = TLS_NO_PRIVKEY; + return treq; +} + +static void tls_handshake_remote_peerids(struct tls_handshake_req *treq, + struct genl_info *info) +{ + struct nlattr *head = nlmsg_attrdata(info->nlhdr, GENL_HDRLEN); + int rem, len = nlmsg_attrlen(info->nlhdr, GENL_HDRLEN); + struct nlattr *nla; + unsigned int i; + + i = 0; + nla_for_each_attr(nla, head, len, rem) { + if (nla_type(nla) == HANDSHAKE_A_DONE_REMOTE_AUTH) + i++; + } + if (!i) + return; + treq->th_num_peerids = min_t(unsigned int, i, + ARRAY_SIZE(treq->th_peerid)); + + i = 0; + nla_for_each_attr(nla, head, len, rem) { + if (nla_type(nla) == HANDSHAKE_A_DONE_REMOTE_AUTH) + treq->th_peerid[i++] = nla_get_u32(nla); + if (i >= treq->th_num_peerids) + break; + } +} + +/** + * tls_handshake_done - callback to handle a CMD_DONE request + * @req: socket on which the handshake was performed + * @status: session status code + * @info: full results of session establishment + * + */ +static void tls_handshake_done(struct handshake_req *req, + unsigned int status, struct genl_info *info) +{ + struct tls_handshake_req *treq = handshake_req_private(req); + + treq->th_peerid[0] = TLS_NO_PEERID; + if (info) + tls_handshake_remote_peerids(treq, info); + + if (!status) + set_bit(HANDSHAKE_F_REQ_SESSION, &req->hr_flags); + + treq->th_consumer_done(treq->th_consumer_data, -status, + treq->th_peerid[0]); +} + +#if IS_ENABLED(CONFIG_KEYS) +static int tls_handshake_private_keyring(struct tls_handshake_req *treq) +{ + key_ref_t process_keyring_ref, keyring_ref; + int ret; + + if (treq->th_keyring == TLS_NO_KEYRING) + return 0; + + process_keyring_ref = lookup_user_key(KEY_SPEC_PROCESS_KEYRING, + KEY_LOOKUP_CREATE, + KEY_NEED_WRITE); + if (IS_ERR(process_keyring_ref)) { + ret = PTR_ERR(process_keyring_ref); + goto out; + } + + keyring_ref = lookup_user_key(treq->th_keyring, KEY_LOOKUP_CREATE, + KEY_NEED_LINK); + if (IS_ERR(keyring_ref)) { + ret = PTR_ERR(keyring_ref); + goto out_put_key; + } + + ret = key_link(key_ref_to_ptr(process_keyring_ref), + key_ref_to_ptr(keyring_ref)); + + key_ref_put(keyring_ref); +out_put_key: + key_ref_put(process_keyring_ref); +out: + return ret; +} +#else +static int tls_handshake_private_keyring(struct tls_handshake_req *treq) +{ + return 0; +} +#endif + +static int tls_handshake_put_peer_identity(struct sk_buff *msg, + struct tls_handshake_req *treq) +{ + unsigned int i; + + for (i = 0; i < treq->th_num_peerids; i++) + if (nla_put_u32(msg, HANDSHAKE_A_ACCEPT_PEER_IDENTITY, + treq->th_peerid[i]) < 0) + return -EMSGSIZE; + return 0; +} + +static int tls_handshake_put_certificate(struct sk_buff *msg, + struct tls_handshake_req *treq) +{ + struct nlattr *entry_attr; + + if (treq->th_certificate == TLS_NO_CERT && + treq->th_privkey == TLS_NO_PRIVKEY) + return 0; + + entry_attr = nla_nest_start(msg, HANDSHAKE_A_ACCEPT_CERTIFICATE); + if (!entry_attr) + return -EMSGSIZE; + + if (nla_put_u32(msg, HANDSHAKE_A_X509_CERT, + treq->th_certificate) || + nla_put_u32(msg, HANDSHAKE_A_X509_PRIVKEY, + treq->th_privkey)) { + nla_nest_cancel(msg, entry_attr); + return -EMSGSIZE; + } + + nla_nest_end(msg, entry_attr); + return 0; +} + +/** + * tls_handshake_accept - callback to construct a CMD_ACCEPT response + * @req: handshake parameters to return + * @info: generic netlink message context + * @fd: file descriptor to be returned + * + * Returns zero on success, or a negative errno on failure. + */ +static int tls_handshake_accept(struct handshake_req *req, + struct genl_info *info, int fd) +{ + struct tls_handshake_req *treq = handshake_req_private(req); + struct nlmsghdr *hdr; + struct sk_buff *msg; + int ret; + + ret = tls_handshake_private_keyring(treq); + if (ret < 0) + goto out; + + ret = -ENOMEM; + msg = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + goto out; + hdr = handshake_genl_put(msg, info); + if (!hdr) + goto out_cancel; + + ret = -EMSGSIZE; + ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_SOCKFD, fd); + if (ret < 0) + goto out_cancel; + ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_MESSAGE_TYPE, treq->th_type); + if (ret < 0) + goto out_cancel; + if (treq->th_peername) { + ret = nla_put_string(msg, HANDSHAKE_A_ACCEPT_PEERNAME, + treq->th_peername); + if (ret < 0) + goto out_cancel; + } + if (treq->th_timeout_ms) { + ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_TIMEOUT, treq->th_timeout_ms); + if (ret < 0) + goto out_cancel; + } + + ret = nla_put_u32(msg, HANDSHAKE_A_ACCEPT_AUTH_MODE, + treq->th_auth_mode); + if (ret < 0) + goto out_cancel; + switch (treq->th_auth_mode) { + case HANDSHAKE_AUTH_PSK: + ret = tls_handshake_put_peer_identity(msg, treq); + if (ret < 0) + goto out_cancel; + break; + case HANDSHAKE_AUTH_X509: + ret = tls_handshake_put_certificate(msg, treq); + if (ret < 0) + goto out_cancel; + break; + } + + genlmsg_end(msg, hdr); + return genlmsg_reply(msg, info); + +out_cancel: + genlmsg_cancel(msg, hdr); +out: + return ret; +} + +static const struct handshake_proto tls_handshake_proto = { + .hp_handler_class = HANDSHAKE_HANDLER_CLASS_TLSHD, + .hp_privsize = sizeof(struct tls_handshake_req), + .hp_flags = BIT(HANDSHAKE_F_PROTO_NOTIFY), + + .hp_accept = tls_handshake_accept, + .hp_done = tls_handshake_done, +}; + +/** + * tls_client_hello_anon - request an anonymous TLS handshake on a socket + * @args: socket and handshake parameters for this request + * @flags: memory allocation control flags + * + * Return values: + * %0: Handshake request enqueue; ->done will be called when complete + * %-ESRCH: No user agent is available + * %-ENOMEM: Memory allocation failed + */ +int tls_client_hello_anon(const struct tls_handshake_args *args, gfp_t flags) +{ + struct tls_handshake_req *treq; + struct handshake_req *req; + + req = handshake_req_alloc(&tls_handshake_proto, flags); + if (!req) + return -ENOMEM; + treq = tls_handshake_req_init(req, args); + treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO; + treq->th_auth_mode = HANDSHAKE_AUTH_UNAUTH; + + return handshake_req_submit(args->ta_sock, req, flags); +} +EXPORT_SYMBOL(tls_client_hello_anon); + +/** + * tls_client_hello_x509 - request an x.509-based TLS handshake on a socket + * @args: socket and handshake parameters for this request + * @flags: memory allocation control flags + * + * Return values: + * %0: Handshake request enqueue; ->done will be called when complete + * %-ESRCH: No user agent is available + * %-ENOMEM: Memory allocation failed + */ +int tls_client_hello_x509(const struct tls_handshake_args *args, gfp_t flags) +{ + struct tls_handshake_req *treq; + struct handshake_req *req; + + req = handshake_req_alloc(&tls_handshake_proto, flags); + if (!req) + return -ENOMEM; + treq = tls_handshake_req_init(req, args); + treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO; + treq->th_auth_mode = HANDSHAKE_AUTH_X509; + treq->th_certificate = args->ta_my_cert; + treq->th_privkey = args->ta_my_privkey; + + return handshake_req_submit(args->ta_sock, req, flags); +} +EXPORT_SYMBOL(tls_client_hello_x509); + +/** + * tls_client_hello_psk - request a PSK-based TLS handshake on a socket + * @args: socket and handshake parameters for this request + * @flags: memory allocation control flags + * + * Return values: + * %0: Handshake request enqueue; ->done will be called when complete + * %-EINVAL: Wrong number of local peer IDs + * %-ESRCH: No user agent is available + * %-ENOMEM: Memory allocation failed + */ +int tls_client_hello_psk(const struct tls_handshake_args *args, gfp_t flags) +{ + struct tls_handshake_req *treq; + struct handshake_req *req; + unsigned int i; + + if (!args->ta_num_peerids || + args->ta_num_peerids > ARRAY_SIZE(treq->th_peerid)) + return -EINVAL; + + req = handshake_req_alloc(&tls_handshake_proto, flags); + if (!req) + return -ENOMEM; + treq = tls_handshake_req_init(req, args); + treq->th_type = HANDSHAKE_MSG_TYPE_CLIENTHELLO; + treq->th_auth_mode = HANDSHAKE_AUTH_PSK; + treq->th_num_peerids = args->ta_num_peerids; + for (i = 0; i < args->ta_num_peerids; i++) + treq->th_peerid[i] = args->ta_my_peerids[i]; + + return handshake_req_submit(args->ta_sock, req, flags); +} +EXPORT_SYMBOL(tls_client_hello_psk); + +/** + * tls_server_hello_x509 - request a server TLS handshake on a socket + * @args: socket and handshake parameters for this request + * @flags: memory allocation control flags + * + * Return values: + * %0: Handshake request enqueue; ->done will be called when complete + * %-ESRCH: No user agent is available + * %-ENOMEM: Memory allocation failed + */ +int tls_server_hello_x509(const struct tls_handshake_args *args, gfp_t flags) +{ + struct tls_handshake_req *treq; + struct handshake_req *req; + + req = handshake_req_alloc(&tls_handshake_proto, flags); + if (!req) + return -ENOMEM; + treq = tls_handshake_req_init(req, args); + treq->th_type = HANDSHAKE_MSG_TYPE_SERVERHELLO; + treq->th_auth_mode = HANDSHAKE_AUTH_X509; + treq->th_certificate = args->ta_my_cert; + treq->th_privkey = args->ta_my_privkey; + + return handshake_req_submit(args->ta_sock, req, flags); +} +EXPORT_SYMBOL(tls_server_hello_x509); + +/** + * tls_server_hello_psk - request a server TLS handshake on a socket + * @args: socket and handshake parameters for this request + * @flags: memory allocation control flags + * + * Return values: + * %0: Handshake request enqueue; ->done will be called when complete + * %-ESRCH: No user agent is available + * %-ENOMEM: Memory allocation failed + */ +int tls_server_hello_psk(const struct tls_handshake_args *args, gfp_t flags) +{ + struct tls_handshake_req *treq; + struct handshake_req *req; + + req = handshake_req_alloc(&tls_handshake_proto, flags); + if (!req) + return -ENOMEM; + treq = tls_handshake_req_init(req, args); + treq->th_type = HANDSHAKE_MSG_TYPE_SERVERHELLO; + treq->th_auth_mode = HANDSHAKE_AUTH_PSK; + treq->th_num_peerids = 1; + treq->th_peerid[0] = args->ta_my_peerids[0]; + + return handshake_req_submit(args->ta_sock, req, flags); +} +EXPORT_SYMBOL(tls_server_hello_psk); + +/** + * tls_handshake_cancel - cancel a pending handshake + * @sk: socket on which there is an ongoing handshake + * + * Request cancellation races with request completion. To determine + * who won, callers examine the return value from this function. + * + * Return values: + * %true - Uncompleted handshake request was canceled + * %false - Handshake request already completed or not found + */ +bool tls_handshake_cancel(struct sock *sk) +{ + return handshake_req_cancel(sk); +} +EXPORT_SYMBOL(tls_handshake_cancel); + +/** + * tls_handshake_close - send a Closure alert + * @sock: an open socket + * + */ +void tls_handshake_close(struct socket *sock) +{ + struct handshake_req *req; + + req = handshake_req_hash_lookup(sock->sk); + if (!req) + return; + if (!test_and_clear_bit(HANDSHAKE_F_REQ_SESSION, &req->hr_flags)) + return; + tls_alert_send(sock, TLS_ALERT_LEVEL_WARNING, + TLS_ALERT_DESC_CLOSE_NOTIFY); +} +EXPORT_SYMBOL(tls_handshake_close); |