2 #include <linux/ceph/ceph_debug.h>
5 #include <linux/scatterlist.h>
6 #include <linux/slab.h>
7 #include <crypto/aes.h>
8 #include <crypto/skcipher.h>
9 #include <linux/key-type.h>
11 #include <keys/ceph-type.h>
12 #include <keys/user-type.h>
13 #include <linux/ceph/decode.h>
17 * Set ->key and ->tfm. The rest of the key should be filled in before
18 * this function is called.
20 static int set_secret(struct ceph_crypto_key *key, void *buf)
22 unsigned int noio_flag;
29 case CEPH_CRYPTO_NONE:
30 return 0; /* nothing to do */
38 key->key = kmemdup(buf, key->len, GFP_NOIO);
44 /* crypto_alloc_skcipher() allocates with GFP_KERNEL */
45 noio_flag = memalloc_noio_save();
46 key->tfm = crypto_alloc_skcipher("cbc(aes)", 0, CRYPTO_ALG_ASYNC);
47 memalloc_noio_restore(noio_flag);
48 if (IS_ERR(key->tfm)) {
49 ret = PTR_ERR(key->tfm);
54 ret = crypto_skcipher_setkey(key->tfm, key->key, key->len);
61 ceph_crypto_key_destroy(key);
65 int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
66 const struct ceph_crypto_key *src)
68 memcpy(dst, src, sizeof(struct ceph_crypto_key));
69 return set_secret(dst, src->key);
72 int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
74 if (*p + sizeof(u16) + sizeof(key->created) +
75 sizeof(u16) + key->len > end)
77 ceph_encode_16(p, key->type);
78 ceph_encode_copy(p, &key->created, sizeof(key->created));
79 ceph_encode_16(p, key->len);
80 ceph_encode_copy(p, key->key, key->len);
84 int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
88 ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
89 key->type = ceph_decode_16(p);
90 ceph_decode_copy(p, &key->created, sizeof(key->created));
91 key->len = ceph_decode_16(p);
92 ceph_decode_need(p, end, key->len, bad);
93 ret = set_secret(key, *p);
98 dout("failed to decode crypto key\n");
102 int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
104 int inlen = strlen(inkey);
105 int blen = inlen * 3 / 4;
109 dout("crypto_key_unarmor %s\n", inkey);
110 buf = kmalloc(blen, GFP_NOFS);
113 blen = ceph_unarmor(buf, inkey, inkey+inlen);
120 ret = ceph_crypto_key_decode(key, &p, p + blen);
124 dout("crypto_key_unarmor key %p type %d len %d\n", key,
125 key->type, key->len);
129 void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
134 crypto_free_skcipher(key->tfm);
139 static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
142 * Should be used for buffers allocated with ceph_kvmalloc().
143 * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
144 * in-buffer (msg front).
146 * Dispose of @sgt with teardown_sgtable().
148 * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
149 * in cases where a single sg is sufficient. No attempt to reduce the
150 * number of sgs by squeezing physically contiguous pages together is
151 * made though, for simplicity.
153 static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
154 const void *buf, unsigned int buf_len)
156 struct scatterlist *sg;
157 const bool is_vmalloc = is_vmalloc_addr(buf);
158 unsigned int off = offset_in_page(buf);
159 unsigned int chunk_cnt = 1;
160 unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
165 memset(sgt, 0, sizeof(*sgt));
170 chunk_cnt = chunk_len >> PAGE_SHIFT;
171 chunk_len = PAGE_SIZE;
175 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
179 WARN_ON(chunk_cnt != 1);
180 sg_init_table(prealloc_sg, 1);
181 sgt->sgl = prealloc_sg;
182 sgt->nents = sgt->orig_nents = 1;
185 for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
187 unsigned int len = min(chunk_len - off, buf_len);
190 page = vmalloc_to_page(buf);
192 page = virt_to_page(buf);
194 sg_set_page(sg, page, len, off);
200 WARN_ON(buf_len != 0);
205 static void teardown_sgtable(struct sg_table *sgt)
207 if (sgt->orig_nents > 1)
211 static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
212 void *buf, int buf_len, int in_len, int *pout_len)
214 SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
216 struct scatterlist prealloc_sg;
217 char iv[AES_BLOCK_SIZE] __aligned(8);
218 int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
219 int crypt_len = encrypt ? in_len + pad_byte : in_len;
222 WARN_ON(crypt_len > buf_len);
224 memset(buf + in_len, pad_byte, pad_byte);
225 ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
229 memcpy(iv, aes_iv, AES_BLOCK_SIZE);
230 skcipher_request_set_tfm(req, key->tfm);
231 skcipher_request_set_callback(req, 0, NULL, NULL);
232 skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
235 print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
236 key->key, key->len, 1);
237 print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
241 ret = crypto_skcipher_encrypt(req);
243 ret = crypto_skcipher_decrypt(req);
244 skcipher_request_zero(req);
246 pr_err("%s %scrypt failed: %d\n", __func__,
247 encrypt ? "en" : "de", ret);
251 print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
256 *pout_len = crypt_len;
258 pad_byte = *(char *)(buf + in_len - 1);
259 if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
260 in_len >= pad_byte) {
261 *pout_len = in_len - pad_byte;
263 pr_err("%s got bad padding %d on in_len %d\n",
264 __func__, pad_byte, in_len);
271 teardown_sgtable(&sgt);
275 int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
276 void *buf, int buf_len, int in_len, int *pout_len)
279 case CEPH_CRYPTO_NONE:
282 case CEPH_CRYPTO_AES:
283 return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
290 static int ceph_key_preparse(struct key_preparsed_payload *prep)
292 struct ceph_crypto_key *ckey;
293 size_t datalen = prep->datalen;
298 if (datalen <= 0 || datalen > 32767 || !prep->data)
302 ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
306 /* TODO ceph_crypto_key_decode should really take const input */
307 p = (void *)prep->data;
308 ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
312 prep->payload.data[0] = ckey;
313 prep->quotalen = datalen;
322 static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
324 struct ceph_crypto_key *ckey = prep->payload.data[0];
325 ceph_crypto_key_destroy(ckey);
329 static void ceph_key_destroy(struct key *key)
331 struct ceph_crypto_key *ckey = key->payload.data[0];
333 ceph_crypto_key_destroy(ckey);
337 struct key_type key_type_ceph = {
339 .preparse = ceph_key_preparse,
340 .free_preparse = ceph_key_free_preparse,
341 .instantiate = generic_key_instantiate,
342 .destroy = ceph_key_destroy,
345 int ceph_crypto_init(void) {
346 return register_key_type(&key_type_ceph);
349 void ceph_crypto_shutdown(void) {
350 unregister_key_type(&key_type_ceph);