2 #include <linux/ceph/ceph_debug.h>
5 #include <linux/scatterlist.h>
6 #include <linux/sched.h>
7 #include <linux/slab.h>
8 #include <crypto/aes.h>
9 #include <crypto/skcipher.h>
10 #include <linux/key-type.h>
11 #include <linux/sched/mm.h>
13 #include <keys/ceph-type.h>
14 #include <keys/user-type.h>
15 #include <linux/ceph/decode.h>
19 * Set ->key and ->tfm. The rest of the key should be filled in before
20 * this function is called.
22 static int set_secret(struct ceph_crypto_key *key, void *buf)
24 unsigned int noio_flag;
31 case CEPH_CRYPTO_NONE:
32 return 0; /* nothing to do */
40 key->key = kmemdup(buf, key->len, GFP_NOIO);
46 /* crypto_alloc_skcipher() allocates with GFP_KERNEL */
47 noio_flag = memalloc_noio_save();
48 key->tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
49 memalloc_noio_restore(noio_flag);
50 if (IS_ERR(key->tfm)) {
51 ret = PTR_ERR(key->tfm);
56 ret = crypto_skcipher_setkey(key->tfm, key->key, key->len);
63 ceph_crypto_key_destroy(key);
67 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
68 const struct ceph_crypto_key *src)
70 memcpy(dst, src, sizeof(struct ceph_crypto_key));
71 return set_secret(dst, src->key);
74 int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
76 if (*p + sizeof(u16) + sizeof(key->created) +
77 sizeof(u16) + key->len > end)
79 ceph_encode_16(p, key->type);
80 ceph_encode_copy(p, &key->created, sizeof(key->created));
81 ceph_encode_16(p, key->len);
82 ceph_encode_copy(p, key->key, key->len);
86 int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
90 ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
91 key->type = ceph_decode_16(p);
92 ceph_decode_copy(p, &key->created, sizeof(key->created));
93 key->len = ceph_decode_16(p);
94 ceph_decode_need(p, end, key->len, bad);
95 ret = set_secret(key, *p);
100 dout("failed to decode crypto key\n");
104 int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
106 int inlen = strlen(inkey);
107 int blen = inlen * 3 / 4;
111 dout("crypto_key_unarmor %s\n", inkey);
112 buf = kmalloc(blen, GFP_NOFS);
115 blen = ceph_unarmor(buf, inkey, inkey+inlen);
122 ret = ceph_crypto_key_decode(key, &p, p + blen);
126 dout("crypto_key_unarmor key %p type %d len %d\n", key,
127 key->type, key->len);
131 void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
136 crypto_free_skcipher(key->tfm);
141 static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
144 * Should be used for buffers allocated with ceph_kvmalloc().
145 * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
146 * in-buffer (msg front).
148 * Dispose of @sgt with teardown_sgtable().
150 * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
151 * in cases where a single sg is sufficient. No attempt to reduce the
152 * number of sgs by squeezing physically contiguous pages together is
153 * made though, for simplicity.
155 static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
156 const void *buf, unsigned int buf_len)
158 struct scatterlist *sg;
159 const bool is_vmalloc = is_vmalloc_addr(buf);
160 unsigned int off = offset_in_page(buf);
161 unsigned int chunk_cnt = 1;
162 unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
167 memset(sgt, 0, sizeof(*sgt));
172 chunk_cnt = chunk_len >> PAGE_SHIFT;
173 chunk_len = PAGE_SIZE;
177 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
181 WARN_ON(chunk_cnt != 1);
182 sg_init_table(prealloc_sg, 1);
183 sgt->sgl = prealloc_sg;
184 sgt->nents = sgt->orig_nents = 1;
187 for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
189 unsigned int len = min(chunk_len - off, buf_len);
192 page = vmalloc_to_page(buf);
194 page = virt_to_page(buf);
196 sg_set_page(sg, page, len, off);
202 WARN_ON(buf_len != 0);
207 static void teardown_sgtable(struct sg_table *sgt)
209 if (sgt->orig_nents > 1)
213 static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
214 void *buf, int buf_len, int in_len, int *pout_len)
216 SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
218 struct scatterlist prealloc_sg;
219 char iv[AES_BLOCK_SIZE] __aligned(8);
220 int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
221 int crypt_len = encrypt ? in_len + pad_byte : in_len;
224 WARN_ON(crypt_len > buf_len);
226 memset(buf + in_len, pad_byte, pad_byte);
227 ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
231 memcpy(iv, aes_iv, AES_BLOCK_SIZE);
232 skcipher_request_set_tfm(req, key->tfm);
233 skcipher_request_set_callback(req, 0, NULL, NULL);
234 skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
237 print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
238 key->key, key->len, 1);
239 print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
243 ret = crypto_skcipher_encrypt(req);
245 ret = crypto_skcipher_decrypt(req);
246 skcipher_request_zero(req);
248 pr_err("%s %scrypt failed: %d\n", __func__,
249 encrypt ? "en" : "de", ret);
253 print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
258 *pout_len = crypt_len;
260 pad_byte = *(char *)(buf + in_len - 1);
261 if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
262 in_len >= pad_byte) {
263 *pout_len = in_len - pad_byte;
265 pr_err("%s got bad padding %d on in_len %d\n",
266 __func__, pad_byte, in_len);
273 teardown_sgtable(&sgt);
277 int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
278 void *buf, int buf_len, int in_len, int *pout_len)
281 case CEPH_CRYPTO_NONE:
284 case CEPH_CRYPTO_AES:
285 return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
292 static int ceph_key_preparse(struct key_preparsed_payload *prep)
294 struct ceph_crypto_key *ckey;
295 size_t datalen = prep->datalen;
300 if (datalen <= 0 || datalen > 32767 || !prep->data)
304 ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
308 /* TODO ceph_crypto_key_decode should really take const input */
309 p = (void *)prep->data;
310 ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
314 prep->payload.data[0] = ckey;
315 prep->quotalen = datalen;
324 static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
326 struct ceph_crypto_key *ckey = prep->payload.data[0];
327 ceph_crypto_key_destroy(ckey);
331 static void ceph_key_destroy(struct key *key)
333 struct ceph_crypto_key *ckey = key->payload.data[0];
335 ceph_crypto_key_destroy(ckey);
339 struct key_type key_type_ceph = {
341 .preparse = ceph_key_preparse,
342 .free_preparse = ceph_key_free_preparse,
343 .instantiate = generic_key_instantiate,
344 .destroy = ceph_key_destroy,
347 int ceph_crypto_init(void) {
348 return register_key_type(&key_type_ceph);
351 void ceph_crypto_shutdown(void) {
352 unregister_key_type(&key_type_ceph);