1 // SPDX-License-Identifier: GPL-2.0
3 #include <linux/ceph/ceph_debug.h>
6 #include <linux/scatterlist.h>
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <crypto/aes.h>
10 #include <crypto/skcipher.h>
11 #include <linux/key-type.h>
12 #include <linux/sched/mm.h>
14 #include <keys/ceph-type.h>
15 #include <keys/user-type.h>
16 #include <linux/ceph/decode.h>
20 * Set ->key and ->tfm. The rest of the key should be filled in before
21 * this function is called.
23 static int set_secret(struct ceph_crypto_key *key, void *buf)
25 unsigned int noio_flag;
32 case CEPH_CRYPTO_NONE:
33 return 0; /* nothing to do */
41 key->key = kmemdup(buf, key->len, GFP_NOIO);
47 /* crypto_alloc_skcipher() allocates with GFP_KERNEL */
48 noio_flag = memalloc_noio_save();
49 key->tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
50 memalloc_noio_restore(noio_flag);
51 if (IS_ERR(key->tfm)) {
52 ret = PTR_ERR(key->tfm);
57 ret = crypto_skcipher_setkey(key->tfm, key->key, key->len);
64 ceph_crypto_key_destroy(key);
68 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
69 const struct ceph_crypto_key *src)
71 memcpy(dst, src, sizeof(struct ceph_crypto_key));
72 return set_secret(dst, src->key);
75 int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
77 if (*p + sizeof(u16) + sizeof(key->created) +
78 sizeof(u16) + key->len > end)
80 ceph_encode_16(p, key->type);
81 ceph_encode_copy(p, &key->created, sizeof(key->created));
82 ceph_encode_16(p, key->len);
83 ceph_encode_copy(p, key->key, key->len);
87 int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
91 ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
92 key->type = ceph_decode_16(p);
93 ceph_decode_copy(p, &key->created, sizeof(key->created));
94 key->len = ceph_decode_16(p);
95 ceph_decode_need(p, end, key->len, bad);
96 ret = set_secret(key, *p);
101 dout("failed to decode crypto key\n");
105 int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
107 int inlen = strlen(inkey);
108 int blen = inlen * 3 / 4;
112 dout("crypto_key_unarmor %s\n", inkey);
113 buf = kmalloc(blen, GFP_NOFS);
116 blen = ceph_unarmor(buf, inkey, inkey+inlen);
123 ret = ceph_crypto_key_decode(key, &p, p + blen);
127 dout("crypto_key_unarmor key %p type %d len %d\n", key,
128 key->type, key->len);
132 void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
137 crypto_free_skcipher(key->tfm);
142 static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
145 * Should be used for buffers allocated with ceph_kvmalloc().
146 * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
147 * in-buffer (msg front).
149 * Dispose of @sgt with teardown_sgtable().
151 * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
152 * in cases where a single sg is sufficient. No attempt to reduce the
153 * number of sgs by squeezing physically contiguous pages together is
154 * made though, for simplicity.
156 static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
157 const void *buf, unsigned int buf_len)
159 struct scatterlist *sg;
160 const bool is_vmalloc = is_vmalloc_addr(buf);
161 unsigned int off = offset_in_page(buf);
162 unsigned int chunk_cnt = 1;
163 unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
168 memset(sgt, 0, sizeof(*sgt));
173 chunk_cnt = chunk_len >> PAGE_SHIFT;
174 chunk_len = PAGE_SIZE;
178 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
182 WARN_ON(chunk_cnt != 1);
183 sg_init_table(prealloc_sg, 1);
184 sgt->sgl = prealloc_sg;
185 sgt->nents = sgt->orig_nents = 1;
188 for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
190 unsigned int len = min(chunk_len - off, buf_len);
193 page = vmalloc_to_page(buf);
195 page = virt_to_page(buf);
197 sg_set_page(sg, page, len, off);
203 WARN_ON(buf_len != 0);
208 static void teardown_sgtable(struct sg_table *sgt)
210 if (sgt->orig_nents > 1)
214 static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
215 void *buf, int buf_len, int in_len, int *pout_len)
217 SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
219 struct scatterlist prealloc_sg;
220 char iv[AES_BLOCK_SIZE] __aligned(8);
221 int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
222 int crypt_len = encrypt ? in_len + pad_byte : in_len;
225 WARN_ON(crypt_len > buf_len);
227 memset(buf + in_len, pad_byte, pad_byte);
228 ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
232 memcpy(iv, aes_iv, AES_BLOCK_SIZE);
233 skcipher_request_set_tfm(req, key->tfm);
234 skcipher_request_set_callback(req, 0, NULL, NULL);
235 skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
238 print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
239 key->key, key->len, 1);
240 print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
244 ret = crypto_skcipher_encrypt(req);
246 ret = crypto_skcipher_decrypt(req);
247 skcipher_request_zero(req);
249 pr_err("%s %scrypt failed: %d\n", __func__,
250 encrypt ? "en" : "de", ret);
254 print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
259 *pout_len = crypt_len;
261 pad_byte = *(char *)(buf + in_len - 1);
262 if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
263 in_len >= pad_byte) {
264 *pout_len = in_len - pad_byte;
266 pr_err("%s got bad padding %d on in_len %d\n",
267 __func__, pad_byte, in_len);
274 teardown_sgtable(&sgt);
278 int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
279 void *buf, int buf_len, int in_len, int *pout_len)
282 case CEPH_CRYPTO_NONE:
285 case CEPH_CRYPTO_AES:
286 return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
293 static int ceph_key_preparse(struct key_preparsed_payload *prep)
295 struct ceph_crypto_key *ckey;
296 size_t datalen = prep->datalen;
301 if (datalen <= 0 || datalen > 32767 || !prep->data)
305 ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
309 /* TODO ceph_crypto_key_decode should really take const input */
310 p = (void *)prep->data;
311 ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
315 prep->payload.data[0] = ckey;
316 prep->quotalen = datalen;
325 static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
327 struct ceph_crypto_key *ckey = prep->payload.data[0];
328 ceph_crypto_key_destroy(ckey);
332 static void ceph_key_destroy(struct key *key)
334 struct ceph_crypto_key *ckey = key->payload.data[0];
336 ceph_crypto_key_destroy(ckey);
340 struct key_type key_type_ceph = {
342 .preparse = ceph_key_preparse,
343 .free_preparse = ceph_key_free_preparse,
344 .instantiate = generic_key_instantiate,
345 .destroy = ceph_key_destroy,
348 int ceph_crypto_init(void) {
349 return register_key_type(&key_type_ceph);
352 void ceph_crypto_shutdown(void) {
353 unregister_key_type(&key_type_ceph);