Loading...
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/ceph/ceph_debug.h>
4
5#include <linux/err.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>
13
14#include <keys/ceph-type.h>
15#include <keys/user-type.h>
16#include <linux/ceph/decode.h>
17#include "crypto.h"
18
19/*
20 * Set ->key and ->tfm. The rest of the key should be filled in before
21 * this function is called.
22 */
23static int set_secret(struct ceph_crypto_key *key, void *buf)
24{
25 unsigned int noio_flag;
26 int ret;
27
28 key->key = NULL;
29 key->tfm = NULL;
30
31 switch (key->type) {
32 case CEPH_CRYPTO_NONE:
33 return 0; /* nothing to do */
34 case CEPH_CRYPTO_AES:
35 break;
36 default:
37 return -ENOTSUPP;
38 }
39
40 if (!key->len)
41 return -EINVAL;
42
43 key->key = kmemdup(buf, key->len, GFP_NOIO);
44 if (!key->key) {
45 ret = -ENOMEM;
46 goto fail;
47 }
48
49 /* crypto_alloc_sync_skcipher() allocates with GFP_KERNEL */
50 noio_flag = memalloc_noio_save();
51 key->tfm = crypto_alloc_sync_skcipher("cbc(aes)", 0, 0);
52 memalloc_noio_restore(noio_flag);
53 if (IS_ERR(key->tfm)) {
54 ret = PTR_ERR(key->tfm);
55 key->tfm = NULL;
56 goto fail;
57 }
58
59 ret = crypto_sync_skcipher_setkey(key->tfm, key->key, key->len);
60 if (ret)
61 goto fail;
62
63 return 0;
64
65fail:
66 ceph_crypto_key_destroy(key);
67 return ret;
68}
69
70int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
71 const struct ceph_crypto_key *src)
72{
73 memcpy(dst, src, sizeof(struct ceph_crypto_key));
74 return set_secret(dst, src->key);
75}
76
77int ceph_crypto_key_encode(struct ceph_crypto_key *key, void **p, void *end)
78{
79 if (*p + sizeof(u16) + sizeof(key->created) +
80 sizeof(u16) + key->len > end)
81 return -ERANGE;
82 ceph_encode_16(p, key->type);
83 ceph_encode_copy(p, &key->created, sizeof(key->created));
84 ceph_encode_16(p, key->len);
85 ceph_encode_copy(p, key->key, key->len);
86 return 0;
87}
88
89int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
90{
91 int ret;
92
93 ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
94 key->type = ceph_decode_16(p);
95 ceph_decode_copy(p, &key->created, sizeof(key->created));
96 key->len = ceph_decode_16(p);
97 ceph_decode_need(p, end, key->len, bad);
98 ret = set_secret(key, *p);
99 *p += key->len;
100 return ret;
101
102bad:
103 dout("failed to decode crypto key\n");
104 return -EINVAL;
105}
106
107int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
108{
109 int inlen = strlen(inkey);
110 int blen = inlen * 3 / 4;
111 void *buf, *p;
112 int ret;
113
114 dout("crypto_key_unarmor %s\n", inkey);
115 buf = kmalloc(blen, GFP_NOFS);
116 if (!buf)
117 return -ENOMEM;
118 blen = ceph_unarmor(buf, inkey, inkey+inlen);
119 if (blen < 0) {
120 kfree(buf);
121 return blen;
122 }
123
124 p = buf;
125 ret = ceph_crypto_key_decode(key, &p, p + blen);
126 kfree(buf);
127 if (ret)
128 return ret;
129 dout("crypto_key_unarmor key %p type %d len %d\n", key,
130 key->type, key->len);
131 return 0;
132}
133
134void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
135{
136 if (key) {
137 kfree(key->key);
138 key->key = NULL;
139 if (key->tfm) {
140 crypto_free_sync_skcipher(key->tfm);
141 key->tfm = NULL;
142 }
143 }
144}
145
146static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
147
148/*
149 * Should be used for buffers allocated with ceph_kvmalloc().
150 * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
151 * in-buffer (msg front).
152 *
153 * Dispose of @sgt with teardown_sgtable().
154 *
155 * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
156 * in cases where a single sg is sufficient. No attempt to reduce the
157 * number of sgs by squeezing physically contiguous pages together is
158 * made though, for simplicity.
159 */
160static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
161 const void *buf, unsigned int buf_len)
162{
163 struct scatterlist *sg;
164 const bool is_vmalloc = is_vmalloc_addr(buf);
165 unsigned int off = offset_in_page(buf);
166 unsigned int chunk_cnt = 1;
167 unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
168 int i;
169 int ret;
170
171 if (buf_len == 0) {
172 memset(sgt, 0, sizeof(*sgt));
173 return -EINVAL;
174 }
175
176 if (is_vmalloc) {
177 chunk_cnt = chunk_len >> PAGE_SHIFT;
178 chunk_len = PAGE_SIZE;
179 }
180
181 if (chunk_cnt > 1) {
182 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
183 if (ret)
184 return ret;
185 } else {
186 WARN_ON(chunk_cnt != 1);
187 sg_init_table(prealloc_sg, 1);
188 sgt->sgl = prealloc_sg;
189 sgt->nents = sgt->orig_nents = 1;
190 }
191
192 for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
193 struct page *page;
194 unsigned int len = min(chunk_len - off, buf_len);
195
196 if (is_vmalloc)
197 page = vmalloc_to_page(buf);
198 else
199 page = virt_to_page(buf);
200
201 sg_set_page(sg, page, len, off);
202
203 off = 0;
204 buf += len;
205 buf_len -= len;
206 }
207 WARN_ON(buf_len != 0);
208
209 return 0;
210}
211
212static void teardown_sgtable(struct sg_table *sgt)
213{
214 if (sgt->orig_nents > 1)
215 sg_free_table(sgt);
216}
217
218static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
219 void *buf, int buf_len, int in_len, int *pout_len)
220{
221 SYNC_SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
222 struct sg_table sgt;
223 struct scatterlist prealloc_sg;
224 char iv[AES_BLOCK_SIZE] __aligned(8);
225 int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
226 int crypt_len = encrypt ? in_len + pad_byte : in_len;
227 int ret;
228
229 WARN_ON(crypt_len > buf_len);
230 if (encrypt)
231 memset(buf + in_len, pad_byte, pad_byte);
232 ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
233 if (ret)
234 return ret;
235
236 memcpy(iv, aes_iv, AES_BLOCK_SIZE);
237 skcipher_request_set_sync_tfm(req, key->tfm);
238 skcipher_request_set_callback(req, 0, NULL, NULL);
239 skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
240
241 /*
242 print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
243 key->key, key->len, 1);
244 print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
245 buf, crypt_len, 1);
246 */
247 if (encrypt)
248 ret = crypto_skcipher_encrypt(req);
249 else
250 ret = crypto_skcipher_decrypt(req);
251 skcipher_request_zero(req);
252 if (ret) {
253 pr_err("%s %scrypt failed: %d\n", __func__,
254 encrypt ? "en" : "de", ret);
255 goto out_sgt;
256 }
257 /*
258 print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
259 buf, crypt_len, 1);
260 */
261
262 if (encrypt) {
263 *pout_len = crypt_len;
264 } else {
265 pad_byte = *(char *)(buf + in_len - 1);
266 if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
267 in_len >= pad_byte) {
268 *pout_len = in_len - pad_byte;
269 } else {
270 pr_err("%s got bad padding %d on in_len %d\n",
271 __func__, pad_byte, in_len);
272 ret = -EPERM;
273 goto out_sgt;
274 }
275 }
276
277out_sgt:
278 teardown_sgtable(&sgt);
279 return ret;
280}
281
282int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
283 void *buf, int buf_len, int in_len, int *pout_len)
284{
285 switch (key->type) {
286 case CEPH_CRYPTO_NONE:
287 *pout_len = in_len;
288 return 0;
289 case CEPH_CRYPTO_AES:
290 return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
291 pout_len);
292 default:
293 return -ENOTSUPP;
294 }
295}
296
297static int ceph_key_preparse(struct key_preparsed_payload *prep)
298{
299 struct ceph_crypto_key *ckey;
300 size_t datalen = prep->datalen;
301 int ret;
302 void *p;
303
304 ret = -EINVAL;
305 if (datalen <= 0 || datalen > 32767 || !prep->data)
306 goto err;
307
308 ret = -ENOMEM;
309 ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
310 if (!ckey)
311 goto err;
312
313 /* TODO ceph_crypto_key_decode should really take const input */
314 p = (void *)prep->data;
315 ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
316 if (ret < 0)
317 goto err_ckey;
318
319 prep->payload.data[0] = ckey;
320 prep->quotalen = datalen;
321 return 0;
322
323err_ckey:
324 kfree(ckey);
325err:
326 return ret;
327}
328
329static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
330{
331 struct ceph_crypto_key *ckey = prep->payload.data[0];
332 ceph_crypto_key_destroy(ckey);
333 kfree(ckey);
334}
335
336static void ceph_key_destroy(struct key *key)
337{
338 struct ceph_crypto_key *ckey = key->payload.data[0];
339
340 ceph_crypto_key_destroy(ckey);
341 kfree(ckey);
342}
343
344struct key_type key_type_ceph = {
345 .name = "ceph",
346 .preparse = ceph_key_preparse,
347 .free_preparse = ceph_key_free_preparse,
348 .instantiate = generic_key_instantiate,
349 .destroy = ceph_key_destroy,
350};
351
352int __init ceph_crypto_init(void)
353{
354 return register_key_type(&key_type_ceph);
355}
356
357void ceph_crypto_shutdown(void)
358{
359 unregister_key_type(&key_type_ceph);
360}
1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/ceph/ceph_debug.h>
4
5#include <linux/err.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>
13
14#include <keys/ceph-type.h>
15#include <keys/user-type.h>
16#include <linux/ceph/decode.h>
17#include "crypto.h"
18
19/*
20 * Set ->key and ->tfm. The rest of the key should be filled in before
21 * this function is called.
22 */
23static int set_secret(struct ceph_crypto_key *key, void *buf)
24{
25 unsigned int noio_flag;
26 int ret;
27
28 key->key = NULL;
29 key->tfm = NULL;
30
31 switch (key->type) {
32 case CEPH_CRYPTO_NONE:
33 return 0; /* nothing to do */
34 case CEPH_CRYPTO_AES:
35 break;
36 default:
37 return -ENOTSUPP;
38 }
39
40 if (!key->len)
41 return -EINVAL;
42
43 key->key = kmemdup(buf, key->len, GFP_NOIO);
44 if (!key->key) {
45 ret = -ENOMEM;
46 goto fail;
47 }
48
49 /* crypto_alloc_sync_skcipher() allocates with GFP_KERNEL */
50 noio_flag = memalloc_noio_save();
51 key->tfm = crypto_alloc_sync_skcipher("cbc(aes)", 0, 0);
52 memalloc_noio_restore(noio_flag);
53 if (IS_ERR(key->tfm)) {
54 ret = PTR_ERR(key->tfm);
55 key->tfm = NULL;
56 goto fail;
57 }
58
59 ret = crypto_sync_skcipher_setkey(key->tfm, key->key, key->len);
60 if (ret)
61 goto fail;
62
63 return 0;
64
65fail:
66 ceph_crypto_key_destroy(key);
67 return ret;
68}
69
70int ceph_crypto_key_clone(struct ceph_crypto_key *dst,
71 const struct ceph_crypto_key *src)
72{
73 memcpy(dst, src, sizeof(struct ceph_crypto_key));
74 return set_secret(dst, src->key);
75}
76
77int ceph_crypto_key_decode(struct ceph_crypto_key *key, void **p, void *end)
78{
79 int ret;
80
81 ceph_decode_need(p, end, 2*sizeof(u16) + sizeof(key->created), bad);
82 key->type = ceph_decode_16(p);
83 ceph_decode_copy(p, &key->created, sizeof(key->created));
84 key->len = ceph_decode_16(p);
85 ceph_decode_need(p, end, key->len, bad);
86 ret = set_secret(key, *p);
87 memzero_explicit(*p, key->len);
88 *p += key->len;
89 return ret;
90
91bad:
92 dout("failed to decode crypto key\n");
93 return -EINVAL;
94}
95
96int ceph_crypto_key_unarmor(struct ceph_crypto_key *key, const char *inkey)
97{
98 int inlen = strlen(inkey);
99 int blen = inlen * 3 / 4;
100 void *buf, *p;
101 int ret;
102
103 dout("crypto_key_unarmor %s\n", inkey);
104 buf = kmalloc(blen, GFP_NOFS);
105 if (!buf)
106 return -ENOMEM;
107 blen = ceph_unarmor(buf, inkey, inkey+inlen);
108 if (blen < 0) {
109 kfree(buf);
110 return blen;
111 }
112
113 p = buf;
114 ret = ceph_crypto_key_decode(key, &p, p + blen);
115 kfree(buf);
116 if (ret)
117 return ret;
118 dout("crypto_key_unarmor key %p type %d len %d\n", key,
119 key->type, key->len);
120 return 0;
121}
122
123void ceph_crypto_key_destroy(struct ceph_crypto_key *key)
124{
125 if (key) {
126 kfree_sensitive(key->key);
127 key->key = NULL;
128 if (key->tfm) {
129 crypto_free_sync_skcipher(key->tfm);
130 key->tfm = NULL;
131 }
132 }
133}
134
135static const u8 *aes_iv = (u8 *)CEPH_AES_IV;
136
137/*
138 * Should be used for buffers allocated with kvmalloc().
139 * Currently these are encrypt out-buffer (ceph_buffer) and decrypt
140 * in-buffer (msg front).
141 *
142 * Dispose of @sgt with teardown_sgtable().
143 *
144 * @prealloc_sg is to avoid memory allocation inside sg_alloc_table()
145 * in cases where a single sg is sufficient. No attempt to reduce the
146 * number of sgs by squeezing physically contiguous pages together is
147 * made though, for simplicity.
148 */
149static int setup_sgtable(struct sg_table *sgt, struct scatterlist *prealloc_sg,
150 const void *buf, unsigned int buf_len)
151{
152 struct scatterlist *sg;
153 const bool is_vmalloc = is_vmalloc_addr(buf);
154 unsigned int off = offset_in_page(buf);
155 unsigned int chunk_cnt = 1;
156 unsigned int chunk_len = PAGE_ALIGN(off + buf_len);
157 int i;
158 int ret;
159
160 if (buf_len == 0) {
161 memset(sgt, 0, sizeof(*sgt));
162 return -EINVAL;
163 }
164
165 if (is_vmalloc) {
166 chunk_cnt = chunk_len >> PAGE_SHIFT;
167 chunk_len = PAGE_SIZE;
168 }
169
170 if (chunk_cnt > 1) {
171 ret = sg_alloc_table(sgt, chunk_cnt, GFP_NOFS);
172 if (ret)
173 return ret;
174 } else {
175 WARN_ON(chunk_cnt != 1);
176 sg_init_table(prealloc_sg, 1);
177 sgt->sgl = prealloc_sg;
178 sgt->nents = sgt->orig_nents = 1;
179 }
180
181 for_each_sg(sgt->sgl, sg, sgt->orig_nents, i) {
182 struct page *page;
183 unsigned int len = min(chunk_len - off, buf_len);
184
185 if (is_vmalloc)
186 page = vmalloc_to_page(buf);
187 else
188 page = virt_to_page(buf);
189
190 sg_set_page(sg, page, len, off);
191
192 off = 0;
193 buf += len;
194 buf_len -= len;
195 }
196 WARN_ON(buf_len != 0);
197
198 return 0;
199}
200
201static void teardown_sgtable(struct sg_table *sgt)
202{
203 if (sgt->orig_nents > 1)
204 sg_free_table(sgt);
205}
206
207static int ceph_aes_crypt(const struct ceph_crypto_key *key, bool encrypt,
208 void *buf, int buf_len, int in_len, int *pout_len)
209{
210 SYNC_SKCIPHER_REQUEST_ON_STACK(req, key->tfm);
211 struct sg_table sgt;
212 struct scatterlist prealloc_sg;
213 char iv[AES_BLOCK_SIZE] __aligned(8);
214 int pad_byte = AES_BLOCK_SIZE - (in_len & (AES_BLOCK_SIZE - 1));
215 int crypt_len = encrypt ? in_len + pad_byte : in_len;
216 int ret;
217
218 WARN_ON(crypt_len > buf_len);
219 if (encrypt)
220 memset(buf + in_len, pad_byte, pad_byte);
221 ret = setup_sgtable(&sgt, &prealloc_sg, buf, crypt_len);
222 if (ret)
223 return ret;
224
225 memcpy(iv, aes_iv, AES_BLOCK_SIZE);
226 skcipher_request_set_sync_tfm(req, key->tfm);
227 skcipher_request_set_callback(req, 0, NULL, NULL);
228 skcipher_request_set_crypt(req, sgt.sgl, sgt.sgl, crypt_len, iv);
229
230 /*
231 print_hex_dump(KERN_ERR, "key: ", DUMP_PREFIX_NONE, 16, 1,
232 key->key, key->len, 1);
233 print_hex_dump(KERN_ERR, " in: ", DUMP_PREFIX_NONE, 16, 1,
234 buf, crypt_len, 1);
235 */
236 if (encrypt)
237 ret = crypto_skcipher_encrypt(req);
238 else
239 ret = crypto_skcipher_decrypt(req);
240 skcipher_request_zero(req);
241 if (ret) {
242 pr_err("%s %scrypt failed: %d\n", __func__,
243 encrypt ? "en" : "de", ret);
244 goto out_sgt;
245 }
246 /*
247 print_hex_dump(KERN_ERR, "out: ", DUMP_PREFIX_NONE, 16, 1,
248 buf, crypt_len, 1);
249 */
250
251 if (encrypt) {
252 *pout_len = crypt_len;
253 } else {
254 pad_byte = *(char *)(buf + in_len - 1);
255 if (pad_byte > 0 && pad_byte <= AES_BLOCK_SIZE &&
256 in_len >= pad_byte) {
257 *pout_len = in_len - pad_byte;
258 } else {
259 pr_err("%s got bad padding %d on in_len %d\n",
260 __func__, pad_byte, in_len);
261 ret = -EPERM;
262 goto out_sgt;
263 }
264 }
265
266out_sgt:
267 teardown_sgtable(&sgt);
268 return ret;
269}
270
271int ceph_crypt(const struct ceph_crypto_key *key, bool encrypt,
272 void *buf, int buf_len, int in_len, int *pout_len)
273{
274 switch (key->type) {
275 case CEPH_CRYPTO_NONE:
276 *pout_len = in_len;
277 return 0;
278 case CEPH_CRYPTO_AES:
279 return ceph_aes_crypt(key, encrypt, buf, buf_len, in_len,
280 pout_len);
281 default:
282 return -ENOTSUPP;
283 }
284}
285
286static int ceph_key_preparse(struct key_preparsed_payload *prep)
287{
288 struct ceph_crypto_key *ckey;
289 size_t datalen = prep->datalen;
290 int ret;
291 void *p;
292
293 ret = -EINVAL;
294 if (datalen <= 0 || datalen > 32767 || !prep->data)
295 goto err;
296
297 ret = -ENOMEM;
298 ckey = kmalloc(sizeof(*ckey), GFP_KERNEL);
299 if (!ckey)
300 goto err;
301
302 /* TODO ceph_crypto_key_decode should really take const input */
303 p = (void *)prep->data;
304 ret = ceph_crypto_key_decode(ckey, &p, (char*)prep->data+datalen);
305 if (ret < 0)
306 goto err_ckey;
307
308 prep->payload.data[0] = ckey;
309 prep->quotalen = datalen;
310 return 0;
311
312err_ckey:
313 kfree(ckey);
314err:
315 return ret;
316}
317
318static void ceph_key_free_preparse(struct key_preparsed_payload *prep)
319{
320 struct ceph_crypto_key *ckey = prep->payload.data[0];
321 ceph_crypto_key_destroy(ckey);
322 kfree(ckey);
323}
324
325static void ceph_key_destroy(struct key *key)
326{
327 struct ceph_crypto_key *ckey = key->payload.data[0];
328
329 ceph_crypto_key_destroy(ckey);
330 kfree(ckey);
331}
332
333struct key_type key_type_ceph = {
334 .name = "ceph",
335 .preparse = ceph_key_preparse,
336 .free_preparse = ceph_key_free_preparse,
337 .instantiate = generic_key_instantiate,
338 .destroy = ceph_key_destroy,
339};
340
341int __init ceph_crypto_init(void)
342{
343 return register_key_type(&key_type_ceph);
344}
345
346void ceph_crypto_shutdown(void)
347{
348 unregister_key_type(&key_type_ceph);
349}