1 // SPDX-License-Identifier: GPL-2.0-or-later
4  * Copyright (C) 2017-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
16 #include <keys/user-type.h>
17 #include <keys/big_key-type.h>
24 	u8 *data;  member
25 	struct path path;  member
29 	(struct big_key_payload *)((payload).data)
32  * If the data is under this limit, there's no point creating a shm file to
34  * least as large as the data.
40  * arbitrary blob of data as the payload
59 	struct big_key_payload *payload = to_big_key_payload(prep->payload);  in big_key_preparse()
63 	size_t datalen = prep->datalen;  in big_key_preparse()
67 	BUILD_BUG_ON(sizeof(*payload) != sizeof(prep->payload.data));  in big_key_preparse()
69 	if (datalen <= 0 || datalen > 1024 * 1024 || !prep->data)  in big_key_preparse()
70 		return -EINVAL;  in big_key_preparse()
73 	prep->quotalen = 16;  in big_key_preparse()
75 	payload->length = datalen;  in big_key_preparse()
78 		/* Create a shmem file to store the data in.  This will permit the data  in big_key_preparse()
83 		 * to zero, provided we never define a ->update() call.  in big_key_preparse()
89 			return -ENOMEM;  in big_key_preparse()
94 			ret = -ENOMEM;  in big_key_preparse()
101 		/* encrypt data */  in big_key_preparse()
102 		chacha20poly1305_encrypt(buf, prep->data, datalen, NULL, 0,  in big_key_preparse()
105 		/* save aligned data to file */  in big_key_preparse()
116 				ret = -EIO;  in big_key_preparse()
123 		payload->data = enckey;  in big_key_preparse()
124 		payload->path = file->f_path;  in big_key_preparse()
125 		path_get(&payload->path);  in big_key_preparse()
129 		/* Just store the data in a buffer */  in big_key_preparse()
130 		void *data = kmalloc(datalen, GFP_KERNEL);  in big_key_preparse()  local
132 		if (!data)  in big_key_preparse()
133 			return -ENOMEM;  in big_key_preparse()
135 		payload->data = data;  in big_key_preparse()
136 		memcpy(data, prep->data, prep->datalen);  in big_key_preparse()
154 	struct big_key_payload *payload = to_big_key_payload(prep->payload);  in big_key_free_preparse()
156 	if (prep->datalen > BIG_KEY_FILE_THRESHOLD)  in big_key_free_preparse()
157 		path_put(&payload->path);  in big_key_free_preparse()
158 	kfree_sensitive(payload->data);  in big_key_free_preparse()
163  * - called with the key sem write-locked
167 	struct big_key_payload *payload = to_big_key_payload(key->payload);  in big_key_revoke()
171 	if (key_is_positive(key) && payload->length > BIG_KEY_FILE_THRESHOLD)  in big_key_revoke()
172 		vfs_truncate(&payload->path, 0);  in big_key_revoke()
176  * dispose of the data dangling from the corpse of a big_key key
180 	struct big_key_payload *payload = to_big_key_payload(key->payload);  in big_key_destroy()
182 	if (payload->length > BIG_KEY_FILE_THRESHOLD) {  in big_key_destroy()
183 		path_put(&payload->path);  in big_key_destroy()
184 		payload->path.mnt = NULL;  in big_key_destroy()
185 		payload->path.dentry = NULL;  in big_key_destroy()
187 	kfree_sensitive(payload->data);  in big_key_destroy()
188 	payload->data = NULL;  in big_key_destroy()
198 	ret = key_payload_reserve(key, prep->datalen);  in big_key_update()
213 	struct big_key_payload *payload = to_big_key_payload(key->payload);  in big_key_describe()
215 	seq_puts(m, key->description);  in big_key_describe()
219 			   payload->length,  in big_key_describe()
220 			   payload->length > BIG_KEY_FILE_THRESHOLD ? "file" : "buff");  in big_key_describe()
224  * read the key data
225  * - the key's semaphore is read-locked
229 	struct big_key_payload *payload = to_big_key_payload(key->payload);  in big_key_read()
230 	size_t datalen = payload->length;  in big_key_read()
238 		u8 *buf, *enckey = payload->data;  in big_key_read()
244 			return -ENOMEM;  in big_key_read()
246 		file = dentry_open(&payload->path, O_RDONLY, current_cred());  in big_key_read()
256 				ret = -EIO;  in big_key_read()
261 					       enckey) ? 0 : -EBADMSG;  in big_key_read()
267 		/* copy out decrypted data */  in big_key_read()
276 		memcpy(buffer, payload->data, datalen);  in big_key_read()