From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- fs/smb/client/cifs_spnego.c | 236 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 236 insertions(+) create mode 100644 fs/smb/client/cifs_spnego.c (limited to 'fs/smb/client/cifs_spnego.c') diff --git a/fs/smb/client/cifs_spnego.c b/fs/smb/client/cifs_spnego.c new file mode 100644 index 000000000..1e6819daa --- /dev/null +++ b/fs/smb/client/cifs_spnego.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: LGPL-2.1 +/* + * SPNEGO upcall management for CIFS + * + * Copyright (c) 2007 Red Hat, Inc. + * Author(s): Jeff Layton (jlayton@redhat.com) + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include "cifsglob.h" +#include "cifs_spnego.h" +#include "cifs_debug.h" +#include "cifsproto.h" +static const struct cred *spnego_cred; + +/* create a new cifs key */ +static int +cifs_spnego_key_instantiate(struct key *key, struct key_preparsed_payload *prep) +{ + char *payload; + int ret; + + ret = -ENOMEM; + payload = kmemdup(prep->data, prep->datalen, GFP_KERNEL); + if (!payload) + goto error; + + /* attach the data */ + key->payload.data[0] = payload; + ret = 0; + +error: + return ret; +} + +static void +cifs_spnego_key_destroy(struct key *key) +{ + kfree(key->payload.data[0]); +} + + +/* + * keytype for CIFS spnego keys + */ +struct key_type cifs_spnego_key_type = { + .name = "cifs.spnego", + .instantiate = cifs_spnego_key_instantiate, + .destroy = cifs_spnego_key_destroy, + .describe = user_describe, +}; + +/* length of longest version string e.g. strlen("ver=0xFF") */ +#define MAX_VER_STR_LEN 8 + +/* length of longest security mechanism name, eg in future could have + * strlen(";sec=ntlmsspi") */ +#define MAX_MECH_STR_LEN 13 + +/* strlen of ";host=" */ +#define HOST_KEY_LEN 6 + +/* strlen of ";ip4=" or ";ip6=" */ +#define IP_KEY_LEN 5 + +/* strlen of ";uid=0x" */ +#define UID_KEY_LEN 7 + +/* strlen of ";creduid=0x" */ +#define CREDUID_KEY_LEN 11 + +/* strlen of ";user=" */ +#define USER_KEY_LEN 6 + +/* strlen of ";pid=0x" */ +#define PID_KEY_LEN 7 + +/* get a key struct with a SPNEGO security blob, suitable for session setup */ +struct key * +cifs_get_spnego_key(struct cifs_ses *sesInfo, + struct TCP_Server_Info *server) +{ + struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr; + struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr; + char *description, *dp; + size_t desc_len; + struct key *spnego_key; + const char *hostname = server->hostname; + const struct cred *saved_cred; + + /* length of fields (with semicolons): ver=0xyz ip4=ipaddress + host=hostname sec=mechanism uid=0xFF user=username */ + desc_len = MAX_VER_STR_LEN + + HOST_KEY_LEN + strlen(hostname) + + IP_KEY_LEN + INET6_ADDRSTRLEN + + MAX_MECH_STR_LEN + + UID_KEY_LEN + (sizeof(uid_t) * 2) + + CREDUID_KEY_LEN + (sizeof(uid_t) * 2) + + PID_KEY_LEN + (sizeof(pid_t) * 2) + 1; + + if (sesInfo->user_name) + desc_len += USER_KEY_LEN + strlen(sesInfo->user_name); + + spnego_key = ERR_PTR(-ENOMEM); + description = kzalloc(desc_len, GFP_KERNEL); + if (description == NULL) + goto out; + + dp = description; + /* start with version and hostname portion of UNC string */ + spnego_key = ERR_PTR(-EINVAL); + sprintf(dp, "ver=0x%x;host=%s;", CIFS_SPNEGO_UPCALL_VERSION, + hostname); + dp = description + strlen(description); + + /* add the server address */ + if (server->dstaddr.ss_family == AF_INET) + sprintf(dp, "ip4=%pI4", &sa->sin_addr); + else if (server->dstaddr.ss_family == AF_INET6) + sprintf(dp, "ip6=%pI6", &sa6->sin6_addr); + else + goto out; + + dp = description + strlen(description); + + /* for now, only sec=krb5 and sec=mskrb5 are valid */ + if (server->sec_kerberos) + sprintf(dp, ";sec=krb5"); + else if (server->sec_mskerberos) + sprintf(dp, ";sec=mskrb5"); + else { + cifs_dbg(VFS, "unknown or missing server auth type, use krb5\n"); + sprintf(dp, ";sec=krb5"); + } + + dp = description + strlen(description); + sprintf(dp, ";uid=0x%x", + from_kuid_munged(&init_user_ns, sesInfo->linux_uid)); + + dp = description + strlen(description); + sprintf(dp, ";creduid=0x%x", + from_kuid_munged(&init_user_ns, sesInfo->cred_uid)); + + if (sesInfo->user_name) { + dp = description + strlen(description); + sprintf(dp, ";user=%s", sesInfo->user_name); + } + + dp = description + strlen(description); + sprintf(dp, ";pid=0x%x", current->pid); + + cifs_dbg(FYI, "key description = %s\n", description); + saved_cred = override_creds(spnego_cred); + spnego_key = request_key(&cifs_spnego_key_type, description, ""); + revert_creds(saved_cred); + +#ifdef CONFIG_CIFS_DEBUG2 + if (cifsFYI && !IS_ERR(spnego_key)) { + struct cifs_spnego_msg *msg = spnego_key->payload.data[0]; + cifs_dump_mem("SPNEGO reply blob:", msg->data, min(1024U, + msg->secblob_len + msg->sesskey_len)); + } +#endif /* CONFIG_CIFS_DEBUG2 */ + +out: + kfree(description); + return spnego_key; +} + +int +init_cifs_spnego(void) +{ + struct cred *cred; + struct key *keyring; + int ret; + + cifs_dbg(FYI, "Registering the %s key type\n", + cifs_spnego_key_type.name); + + /* + * Create an override credential set with special thread keyring for + * spnego upcalls. + */ + + cred = prepare_kernel_cred(NULL); + if (!cred) + return -ENOMEM; + + keyring = keyring_alloc(".cifs_spnego", + GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, cred, + (KEY_POS_ALL & ~KEY_POS_SETATTR) | + KEY_USR_VIEW | KEY_USR_READ, + KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL); + if (IS_ERR(keyring)) { + ret = PTR_ERR(keyring); + goto failed_put_cred; + } + + ret = register_key_type(&cifs_spnego_key_type); + if (ret < 0) + goto failed_put_key; + + /* + * instruct request_key() to use this special keyring as a cache for + * the results it looks up + */ + set_bit(KEY_FLAG_ROOT_CAN_CLEAR, &keyring->flags); + cred->thread_keyring = keyring; + cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING; + spnego_cred = cred; + + cifs_dbg(FYI, "cifs spnego keyring: %d\n", key_serial(keyring)); + return 0; + +failed_put_key: + key_put(keyring); +failed_put_cred: + put_cred(cred); + return ret; +} + +void +exit_cifs_spnego(void) +{ + key_revoke(spnego_cred->thread_keyring); + unregister_key_type(&cifs_spnego_key_type); + put_cred(spnego_cred); + cifs_dbg(FYI, "Unregistered %s key type\n", cifs_spnego_key_type.name); +} -- cgit v1.2.3