xref: /freebsd/crypto/openssl/engines/e_afalg.c (revision aa906e2a4957db700d9e6cc60857e1afe1aecc85)
1 /*
2  * Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 /* Required for vmsplice */
11 #ifndef _GNU_SOURCE
12 # define _GNU_SOURCE
13 #endif
14 #include <stdio.h>
15 #include <string.h>
16 #include <unistd.h>
17 
18 #include <openssl/engine.h>
19 #include <openssl/async.h>
20 #include <openssl/err.h>
21 #include "internal/nelem.h"
22 
23 #include <sys/socket.h>
24 #include <linux/version.h>
25 #define K_MAJ   4
26 #define K_MIN1  1
27 #define K_MIN2  0
28 #if LINUX_VERSION_CODE < KERNEL_VERSION(K_MAJ, K_MIN1, K_MIN2) || \
29     !defined(AF_ALG)
30 # ifndef PEDANTIC
31 #  warning "AFALG ENGINE requires Kernel Headers >= 4.1.0"
32 #  warning "Skipping Compilation of AFALG engine"
33 # endif
34 void engine_load_afalg_int(void);
35 void engine_load_afalg_int(void)
36 {
37 }
38 #else
39 
40 # include <linux/if_alg.h>
41 # include <fcntl.h>
42 # include <sys/utsname.h>
43 
44 # include <linux/aio_abi.h>
45 # include <sys/syscall.h>
46 # include <errno.h>
47 
48 # include "e_afalg.h"
49 # include "e_afalg_err.c"
50 
51 # ifndef SOL_ALG
52 #  define SOL_ALG 279
53 # endif
54 
55 # ifdef ALG_ZERO_COPY
56 #  ifndef SPLICE_F_GIFT
57 #   define SPLICE_F_GIFT    (0x08)
58 #  endif
59 # endif
60 
61 # define ALG_AES_IV_LEN 16
62 # define ALG_IV_LEN(len) (sizeof(struct af_alg_iv) + (len))
63 # define ALG_OP_TYPE     unsigned int
64 # define ALG_OP_LEN      (sizeof(ALG_OP_TYPE))
65 
66 # ifdef OPENSSL_NO_DYNAMIC_ENGINE
67 void engine_load_afalg_int(void);
68 # endif
69 
70 /* Local Linkage Functions */
71 static int afalg_init_aio(afalg_aio *aio);
72 static int afalg_fin_cipher_aio(afalg_aio *ptr, int sfd,
73                                 unsigned char *buf, size_t len);
74 static int afalg_create_sk(afalg_ctx *actx, const char *ciphertype,
75                                 const char *ciphername);
76 static int afalg_destroy(ENGINE *e);
77 static int afalg_init(ENGINE *e);
78 static int afalg_finish(ENGINE *e);
79 static const EVP_CIPHER *afalg_aes_cbc(int nid);
80 static cbc_handles *get_cipher_handle(int nid);
81 static int afalg_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
82                          const int **nids, int nid);
83 static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
84                              const unsigned char *iv, int enc);
85 static int afalg_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
86                            const unsigned char *in, size_t inl);
87 static int afalg_cipher_cleanup(EVP_CIPHER_CTX *ctx);
88 static int afalg_chk_platform(void);
89 
90 /* Engine Id and Name */
91 static const char *engine_afalg_id = "afalg";
92 static const char *engine_afalg_name = "AFALG engine support";
93 
94 static int afalg_cipher_nids[] = {
95     NID_aes_128_cbc,
96     NID_aes_192_cbc,
97     NID_aes_256_cbc,
98 };
99 
100 static cbc_handles cbc_handle[] = {{AES_KEY_SIZE_128, NULL},
101                                     {AES_KEY_SIZE_192, NULL},
102                                     {AES_KEY_SIZE_256, NULL}};
103 
104 static ossl_inline int io_setup(unsigned n, aio_context_t *ctx)
105 {
106     return syscall(__NR_io_setup, n, ctx);
107 }
108 
109 static ossl_inline int eventfd(int n)
110 {
111     return syscall(__NR_eventfd2, n, 0);
112 }
113 
114 static ossl_inline int io_destroy(aio_context_t ctx)
115 {
116     return syscall(__NR_io_destroy, ctx);
117 }
118 
119 static ossl_inline int io_read(aio_context_t ctx, long n, struct iocb **iocb)
120 {
121     return syscall(__NR_io_submit, ctx, n, iocb);
122 }
123 
124 static ossl_inline int io_getevents(aio_context_t ctx, long min, long max,
125                                struct io_event *events,
126                                struct timespec *timeout)
127 {
128     return syscall(__NR_io_getevents, ctx, min, max, events, timeout);
129 }
130 
131 static void afalg_waitfd_cleanup(ASYNC_WAIT_CTX *ctx, const void *key,
132                                  OSSL_ASYNC_FD waitfd, void *custom)
133 {
134     close(waitfd);
135 }
136 
137 static int afalg_setup_async_event_notification(afalg_aio *aio)
138 {
139     ASYNC_JOB *job;
140     ASYNC_WAIT_CTX *waitctx;
141     void *custom = NULL;
142     int ret;
143 
144     if ((job = ASYNC_get_current_job()) != NULL) {
145         /* Async mode */
146         waitctx = ASYNC_get_wait_ctx(job);
147         if (waitctx == NULL) {
148             ALG_WARN("%s(%d): ASYNC_get_wait_ctx error", __FILE__, __LINE__);
149             return 0;
150         }
151         /* Get waitfd from ASYNC_WAIT_CTX if it is already set */
152         ret = ASYNC_WAIT_CTX_get_fd(waitctx, engine_afalg_id,
153                                     &aio->efd, &custom);
154         if (ret == 0) {
155             /*
156              * waitfd is not set in ASYNC_WAIT_CTX, create a new one
157              * and set it. efd will be signaled when AIO operation completes
158              */
159             aio->efd = eventfd(0);
160             if (aio->efd == -1) {
161                 ALG_PERR("%s(%d): Failed to get eventfd : ", __FILE__,
162                          __LINE__);
163                 AFALGerr(AFALG_F_AFALG_SETUP_ASYNC_EVENT_NOTIFICATION,
164                          AFALG_R_EVENTFD_FAILED);
165                 return 0;
166             }
167             ret = ASYNC_WAIT_CTX_set_wait_fd(waitctx, engine_afalg_id,
168                                              aio->efd, custom,
169                                              afalg_waitfd_cleanup);
170             if (ret == 0) {
171                 ALG_WARN("%s(%d): Failed to set wait fd", __FILE__, __LINE__);
172                 close(aio->efd);
173                 return 0;
174             }
175             /* make fd non-blocking in async mode */
176             if (fcntl(aio->efd, F_SETFL, O_NONBLOCK) != 0) {
177                 ALG_WARN("%s(%d): Failed to set event fd as NONBLOCKING",
178                          __FILE__, __LINE__);
179             }
180         }
181         aio->mode = MODE_ASYNC;
182     } else {
183         /* Sync mode */
184         aio->efd = eventfd(0);
185         if (aio->efd == -1) {
186             ALG_PERR("%s(%d): Failed to get eventfd : ", __FILE__, __LINE__);
187             AFALGerr(AFALG_F_AFALG_SETUP_ASYNC_EVENT_NOTIFICATION,
188                      AFALG_R_EVENTFD_FAILED);
189             return 0;
190         }
191         aio->mode = MODE_SYNC;
192     }
193     return 1;
194 }
195 
196 static int afalg_init_aio(afalg_aio *aio)
197 {
198     int r = -1;
199 
200     /* Initialise for AIO */
201     aio->aio_ctx = 0;
202     r = io_setup(MAX_INFLIGHTS, &aio->aio_ctx);
203     if (r < 0) {
204         ALG_PERR("%s(%d): io_setup error : ", __FILE__, __LINE__);
205         AFALGerr(AFALG_F_AFALG_INIT_AIO, AFALG_R_IO_SETUP_FAILED);
206         return 0;
207     }
208 
209     memset(aio->cbt, 0, sizeof(aio->cbt));
210     aio->efd = -1;
211     aio->mode = MODE_UNINIT;
212 
213     return 1;
214 }
215 
216 static int afalg_fin_cipher_aio(afalg_aio *aio, int sfd, unsigned char *buf,
217                                 size_t len)
218 {
219     int r;
220     int retry = 0;
221     unsigned int done = 0;
222     struct iocb *cb;
223     struct timespec timeout;
224     struct io_event events[MAX_INFLIGHTS];
225     u_int64_t eval = 0;
226 
227     timeout.tv_sec = 0;
228     timeout.tv_nsec = 0;
229 
230     /* if efd has not been initialised yet do it here */
231     if (aio->mode == MODE_UNINIT) {
232         r = afalg_setup_async_event_notification(aio);
233         if (r == 0)
234             return 0;
235     }
236 
237     cb = &(aio->cbt[0 % MAX_INFLIGHTS]);
238     memset(cb, '\0', sizeof(*cb));
239     cb->aio_fildes = sfd;
240     cb->aio_lio_opcode = IOCB_CMD_PREAD;
241     /*
242      * The pointer has to be converted to unsigned value first to avoid
243      * sign extension on cast to 64 bit value in 32-bit builds
244      */
245     cb->aio_buf = (size_t)buf;
246     cb->aio_offset = 0;
247     cb->aio_data = 0;
248     cb->aio_nbytes = len;
249     cb->aio_flags = IOCB_FLAG_RESFD;
250     cb->aio_resfd = aio->efd;
251 
252     /*
253      * Perform AIO read on AFALG socket, this in turn performs an async
254      * crypto operation in kernel space
255      */
256     r = io_read(aio->aio_ctx, 1, &cb);
257     if (r < 0) {
258         ALG_PWARN("%s(%d): io_read failed : ", __FILE__, __LINE__);
259         return 0;
260     }
261 
262     do {
263         /* While AIO read is being performed pause job */
264         ASYNC_pause_job();
265 
266         /* Check for completion of AIO read */
267         r = read(aio->efd, &eval, sizeof(eval));
268         if (r < 0) {
269             if (errno == EAGAIN || errno == EWOULDBLOCK)
270                 continue;
271             ALG_PERR("%s(%d): read failed for event fd : ", __FILE__, __LINE__);
272             return 0;
273         } else if (r == 0 || eval <= 0) {
274             ALG_WARN("%s(%d): eventfd read %d bytes, eval = %lu\n", __FILE__,
275                      __LINE__, r, eval);
276         }
277         if (eval > 0) {
278 
279             /* Get results of AIO read */
280             r = io_getevents(aio->aio_ctx, 1, MAX_INFLIGHTS,
281                              events, &timeout);
282             if (r > 0) {
283                 /*
284                  * events.res indicates the actual status of the operation.
285                  * Handle the error condition first.
286                  */
287                 if (events[0].res < 0) {
288                     /*
289                      * Underlying operation cannot be completed at the time
290                      * of previous submission. Resubmit for the operation.
291                      */
292                     if (events[0].res == -EBUSY && retry++ < 3) {
293                         r = io_read(aio->aio_ctx, 1, &cb);
294                         if (r < 0) {
295                             ALG_PERR("%s(%d): retry %d for io_read failed : ",
296                                      __FILE__, __LINE__, retry);
297                             return 0;
298                         }
299                         continue;
300                     } else {
301                         /*
302                          * Retries exceed for -EBUSY or unrecoverable error
303                          * condition for this instance of operation.
304                          */
305                         ALG_WARN
306                             ("%s(%d): Crypto Operation failed with code %lld\n",
307                              __FILE__, __LINE__, events[0].res);
308                         return 0;
309                     }
310                 }
311                 /* Operation successful. */
312                 done = 1;
313             } else if (r < 0) {
314                 ALG_PERR("%s(%d): io_getevents failed : ", __FILE__, __LINE__);
315                 return 0;
316             } else {
317                 ALG_WARN("%s(%d): io_geteventd read 0 bytes\n", __FILE__,
318                          __LINE__);
319             }
320         }
321     } while (!done);
322 
323     return 1;
324 }
325 
326 static ossl_inline void afalg_set_op_sk(struct cmsghdr *cmsg,
327                                    const ALG_OP_TYPE op)
328 {
329     cmsg->cmsg_level = SOL_ALG;
330     cmsg->cmsg_type = ALG_SET_OP;
331     cmsg->cmsg_len = CMSG_LEN(ALG_OP_LEN);
332     memcpy(CMSG_DATA(cmsg), &op, ALG_OP_LEN);
333 }
334 
335 static void afalg_set_iv_sk(struct cmsghdr *cmsg, const unsigned char *iv,
336                             const unsigned int len)
337 {
338     struct af_alg_iv *aiv;
339 
340     cmsg->cmsg_level = SOL_ALG;
341     cmsg->cmsg_type = ALG_SET_IV;
342     cmsg->cmsg_len = CMSG_LEN(ALG_IV_LEN(len));
343     aiv = (struct af_alg_iv *)CMSG_DATA(cmsg);
344     aiv->ivlen = len;
345     memcpy(aiv->iv, iv, len);
346 }
347 
348 static ossl_inline int afalg_set_key(afalg_ctx *actx, const unsigned char *key,
349                                 const int klen)
350 {
351     int ret;
352     ret = setsockopt(actx->bfd, SOL_ALG, ALG_SET_KEY, key, klen);
353     if (ret < 0) {
354         ALG_PERR("%s(%d): Failed to set socket option : ", __FILE__, __LINE__);
355         AFALGerr(AFALG_F_AFALG_SET_KEY, AFALG_R_SOCKET_SET_KEY_FAILED);
356         return 0;
357     }
358     return 1;
359 }
360 
361 static int afalg_create_sk(afalg_ctx *actx, const char *ciphertype,
362                                 const char *ciphername)
363 {
364     struct sockaddr_alg sa;
365     int r = -1;
366 
367     actx->bfd = actx->sfd = -1;
368 
369     memset(&sa, 0, sizeof(sa));
370     sa.salg_family = AF_ALG;
371     OPENSSL_strlcpy((char *) sa.salg_type, ciphertype, sizeof(sa.salg_type));
372     OPENSSL_strlcpy((char *) sa.salg_name, ciphername, sizeof(sa.salg_name));
373 
374     actx->bfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
375     if (actx->bfd == -1) {
376         ALG_PERR("%s(%d): Failed to open socket : ", __FILE__, __LINE__);
377         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_CREATE_FAILED);
378         goto err;
379     }
380 
381     r = bind(actx->bfd, (struct sockaddr *)&sa, sizeof(sa));
382     if (r < 0) {
383         ALG_PERR("%s(%d): Failed to bind socket : ", __FILE__, __LINE__);
384         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_BIND_FAILED);
385         goto err;
386     }
387 
388     actx->sfd = accept(actx->bfd, NULL, 0);
389     if (actx->sfd < 0) {
390         ALG_PERR("%s(%d): Socket Accept Failed : ", __FILE__, __LINE__);
391         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_ACCEPT_FAILED);
392         goto err;
393     }
394 
395     return 1;
396 
397  err:
398     if (actx->bfd >= 0)
399         close(actx->bfd);
400     if (actx->sfd >= 0)
401         close(actx->sfd);
402     actx->bfd = actx->sfd = -1;
403     return 0;
404 }
405 
406 static int afalg_start_cipher_sk(afalg_ctx *actx, const unsigned char *in,
407                                  size_t inl, const unsigned char *iv,
408                                  unsigned int enc)
409 {
410     struct msghdr msg;
411     struct cmsghdr *cmsg;
412     struct iovec iov;
413     ssize_t sbytes;
414 # ifdef ALG_ZERO_COPY
415     int ret;
416 # endif
417     char cbuf[CMSG_SPACE(ALG_IV_LEN(ALG_AES_IV_LEN)) + CMSG_SPACE(ALG_OP_LEN)];
418 
419     memset(&msg, 0, sizeof(msg));
420     memset(cbuf, 0, sizeof(cbuf));
421     msg.msg_control = cbuf;
422     msg.msg_controllen = sizeof(cbuf);
423 
424     /*
425      * cipher direction (i.e. encrypt or decrypt) and iv are sent to the
426      * kernel as part of sendmsg()'s ancillary data
427      */
428     cmsg = CMSG_FIRSTHDR(&msg);
429     afalg_set_op_sk(cmsg, enc);
430     cmsg = CMSG_NXTHDR(&msg, cmsg);
431     afalg_set_iv_sk(cmsg, iv, ALG_AES_IV_LEN);
432 
433     /* iov that describes input data */
434     iov.iov_base = (unsigned char *)in;
435     iov.iov_len = inl;
436 
437     msg.msg_flags = MSG_MORE;
438 
439 # ifdef ALG_ZERO_COPY
440     /*
441      * ZERO_COPY mode
442      * Works best when buffer is 4k aligned
443      * OPENS: out of place processing (i.e. out != in)
444      */
445 
446     /* Input data is not sent as part of call to sendmsg() */
447     msg.msg_iovlen = 0;
448     msg.msg_iov = NULL;
449 
450     /* Sendmsg() sends iv and cipher direction to the kernel */
451     sbytes = sendmsg(actx->sfd, &msg, 0);
452     if (sbytes < 0) {
453         ALG_PERR("%s(%d): sendmsg failed for zero copy cipher operation : ",
454                  __FILE__, __LINE__);
455         return 0;
456     }
457 
458     /*
459      * vmsplice and splice are used to pin the user space input buffer for
460      * kernel space processing avoiding copies from user to kernel space
461      */
462     ret = vmsplice(actx->zc_pipe[1], &iov, 1, SPLICE_F_GIFT);
463     if (ret < 0) {
464         ALG_PERR("%s(%d): vmsplice failed : ", __FILE__, __LINE__);
465         return 0;
466     }
467 
468     ret = splice(actx->zc_pipe[0], NULL, actx->sfd, NULL, inl, 0);
469     if (ret < 0) {
470         ALG_PERR("%s(%d): splice failed : ", __FILE__, __LINE__);
471         return 0;
472     }
473 # else
474     msg.msg_iovlen = 1;
475     msg.msg_iov = &iov;
476 
477     /* Sendmsg() sends iv, cipher direction and input data to the kernel */
478     sbytes = sendmsg(actx->sfd, &msg, 0);
479     if (sbytes < 0) {
480         ALG_PERR("%s(%d): sendmsg failed for cipher operation : ", __FILE__,
481                  __LINE__);
482         return 0;
483     }
484 
485     if (sbytes != (ssize_t) inl) {
486         ALG_WARN("Cipher operation send bytes %zd != inlen %zd\n", sbytes,
487                 inl);
488         return 0;
489     }
490 # endif
491 
492     return 1;
493 }
494 
495 static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
496                              const unsigned char *iv, int enc)
497 {
498     int ciphertype;
499     int ret;
500     afalg_ctx *actx;
501     const char *ciphername;
502 
503     if (ctx == NULL || key == NULL) {
504         ALG_WARN("%s(%d): Null Parameter\n", __FILE__, __LINE__);
505         return 0;
506     }
507 
508     if (EVP_CIPHER_CTX_cipher(ctx) == NULL) {
509         ALG_WARN("%s(%d): Cipher object NULL\n", __FILE__, __LINE__);
510         return 0;
511     }
512 
513     actx = EVP_CIPHER_CTX_get_cipher_data(ctx);
514     if (actx == NULL) {
515         ALG_WARN("%s(%d): Cipher data NULL\n", __FILE__, __LINE__);
516         return 0;
517     }
518 
519     ciphertype = EVP_CIPHER_CTX_nid(ctx);
520     switch (ciphertype) {
521     case NID_aes_128_cbc:
522     case NID_aes_192_cbc:
523     case NID_aes_256_cbc:
524         ciphername = "cbc(aes)";
525         break;
526     default:
527         ALG_WARN("%s(%d): Unsupported Cipher type %d\n", __FILE__, __LINE__,
528                  ciphertype);
529         return 0;
530     }
531 
532     if (ALG_AES_IV_LEN != EVP_CIPHER_CTX_iv_length(ctx)) {
533         ALG_WARN("%s(%d): Unsupported IV length :%d\n", __FILE__, __LINE__,
534                  EVP_CIPHER_CTX_iv_length(ctx));
535         return 0;
536     }
537 
538     /* Setup AFALG socket for crypto processing */
539     ret = afalg_create_sk(actx, "skcipher", ciphername);
540     if (ret < 1)
541         return 0;
542 
543 
544     ret = afalg_set_key(actx, key, EVP_CIPHER_CTX_key_length(ctx));
545     if (ret < 1)
546         goto err;
547 
548     /* Setup AIO ctx to allow async AFALG crypto processing */
549     if (afalg_init_aio(&actx->aio) == 0)
550         goto err;
551 
552 # ifdef ALG_ZERO_COPY
553     pipe(actx->zc_pipe);
554 # endif
555 
556     actx->init_done = MAGIC_INIT_NUM;
557 
558     return 1;
559 
560 err:
561     close(actx->sfd);
562     close(actx->bfd);
563     return 0;
564 }
565 
566 static int afalg_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
567                            const unsigned char *in, size_t inl)
568 {
569     afalg_ctx *actx;
570     int ret;
571     char nxtiv[ALG_AES_IV_LEN] = { 0 };
572 
573     if (ctx == NULL || out == NULL || in == NULL) {
574         ALG_WARN("NULL parameter passed to function %s(%d)\n", __FILE__,
575                  __LINE__);
576         return 0;
577     }
578 
579     actx = (afalg_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
580     if (actx == NULL || actx->init_done != MAGIC_INIT_NUM) {
581         ALG_WARN("%s afalg ctx passed\n",
582                  ctx == NULL ? "NULL" : "Uninitialised");
583         return 0;
584     }
585 
586     /*
587      * set iv now for decrypt operation as the input buffer can be
588      * overwritten for inplace operation where in = out.
589      */
590     if (EVP_CIPHER_CTX_encrypting(ctx) == 0) {
591         memcpy(nxtiv, in + (inl - ALG_AES_IV_LEN), ALG_AES_IV_LEN);
592     }
593 
594     /* Send input data to kernel space */
595     ret = afalg_start_cipher_sk(actx, (unsigned char *)in, inl,
596                                 EVP_CIPHER_CTX_iv(ctx),
597                                 EVP_CIPHER_CTX_encrypting(ctx));
598     if (ret < 1) {
599         return 0;
600     }
601 
602     /* Perform async crypto operation in kernel space */
603     ret = afalg_fin_cipher_aio(&actx->aio, actx->sfd, out, inl);
604     if (ret < 1)
605         return 0;
606 
607     if (EVP_CIPHER_CTX_encrypting(ctx)) {
608         memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), out + (inl - ALG_AES_IV_LEN),
609                ALG_AES_IV_LEN);
610     } else {
611         memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), nxtiv, ALG_AES_IV_LEN);
612     }
613 
614     return 1;
615 }
616 
617 static int afalg_cipher_cleanup(EVP_CIPHER_CTX *ctx)
618 {
619     afalg_ctx *actx;
620 
621     if (ctx == NULL) {
622         ALG_WARN("NULL parameter passed to function %s(%d)\n", __FILE__,
623                  __LINE__);
624         return 0;
625     }
626 
627     actx = (afalg_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
628     if (actx == NULL || actx->init_done != MAGIC_INIT_NUM) {
629         ALG_WARN("%s afalg ctx passed\n",
630                  ctx == NULL ? "NULL" : "Uninitialised");
631         return 0;
632     }
633 
634     close(actx->sfd);
635     close(actx->bfd);
636 # ifdef ALG_ZERO_COPY
637     close(actx->zc_pipe[0]);
638     close(actx->zc_pipe[1]);
639 # endif
640     /* close efd in sync mode, async mode is closed in afalg_waitfd_cleanup() */
641     if (actx->aio.mode == MODE_SYNC)
642         close(actx->aio.efd);
643     io_destroy(actx->aio.aio_ctx);
644 
645     return 1;
646 }
647 
648 static cbc_handles *get_cipher_handle(int nid)
649 {
650     switch (nid) {
651     case NID_aes_128_cbc:
652         return &cbc_handle[AES_CBC_128];
653     case NID_aes_192_cbc:
654         return &cbc_handle[AES_CBC_192];
655     case NID_aes_256_cbc:
656         return &cbc_handle[AES_CBC_256];
657     default:
658         return NULL;
659     }
660 }
661 
662 static const EVP_CIPHER *afalg_aes_cbc(int nid)
663 {
664     cbc_handles *cipher_handle = get_cipher_handle(nid);
665     if (cipher_handle->_hidden == NULL
666         && ((cipher_handle->_hidden =
667          EVP_CIPHER_meth_new(nid,
668                              AES_BLOCK_SIZE,
669                              cipher_handle->key_size)) == NULL
670         || !EVP_CIPHER_meth_set_iv_length(cipher_handle->_hidden,
671                                           AES_IV_LEN)
672         || !EVP_CIPHER_meth_set_flags(cipher_handle->_hidden,
673                                       EVP_CIPH_CBC_MODE |
674                                       EVP_CIPH_FLAG_DEFAULT_ASN1)
675         || !EVP_CIPHER_meth_set_init(cipher_handle->_hidden,
676                                      afalg_cipher_init)
677         || !EVP_CIPHER_meth_set_do_cipher(cipher_handle->_hidden,
678                                           afalg_do_cipher)
679         || !EVP_CIPHER_meth_set_cleanup(cipher_handle->_hidden,
680                                         afalg_cipher_cleanup)
681         || !EVP_CIPHER_meth_set_impl_ctx_size(cipher_handle->_hidden,
682                                               sizeof(afalg_ctx)))) {
683         EVP_CIPHER_meth_free(cipher_handle->_hidden);
684         cipher_handle->_hidden= NULL;
685     }
686     return cipher_handle->_hidden;
687 }
688 
689 static int afalg_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
690                          const int **nids, int nid)
691 {
692     int r = 1;
693 
694     if (cipher == NULL) {
695         *nids = afalg_cipher_nids;
696         return (sizeof(afalg_cipher_nids) / sizeof(afalg_cipher_nids[0]));
697     }
698 
699     switch (nid) {
700     case NID_aes_128_cbc:
701     case NID_aes_192_cbc:
702     case NID_aes_256_cbc:
703         *cipher = afalg_aes_cbc(nid);
704         break;
705     default:
706         *cipher = NULL;
707         r = 0;
708     }
709     return r;
710 }
711 
712 static int bind_afalg(ENGINE *e)
713 {
714     /* Ensure the afalg error handling is set up */
715     unsigned short i;
716     ERR_load_AFALG_strings();
717 
718     if (!ENGINE_set_id(e, engine_afalg_id)
719         || !ENGINE_set_name(e, engine_afalg_name)
720         || !ENGINE_set_destroy_function(e, afalg_destroy)
721         || !ENGINE_set_init_function(e, afalg_init)
722         || !ENGINE_set_finish_function(e, afalg_finish)) {
723         AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
724         return 0;
725     }
726 
727     /*
728      * Create _hidden_aes_xxx_cbc by calling afalg_aes_xxx_cbc
729      * now, as bind_aflag can only be called by one thread at a
730      * time.
731      */
732     for(i = 0; i < OSSL_NELEM(afalg_cipher_nids); i++) {
733         if (afalg_aes_cbc(afalg_cipher_nids[i]) == NULL) {
734             AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
735             return 0;
736         }
737     }
738 
739     if (!ENGINE_set_ciphers(e, afalg_ciphers)) {
740         AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
741         return 0;
742     }
743 
744     return 1;
745 }
746 
747 # ifndef OPENSSL_NO_DYNAMIC_ENGINE
748 static int bind_helper(ENGINE *e, const char *id)
749 {
750     if (id && (strcmp(id, engine_afalg_id) != 0))
751         return 0;
752 
753     if (!afalg_chk_platform())
754         return 0;
755 
756     if (!bind_afalg(e))
757         return 0;
758     return 1;
759 }
760 
761 IMPLEMENT_DYNAMIC_CHECK_FN()
762     IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
763 # endif
764 
765 static int afalg_chk_platform(void)
766 {
767     int ret;
768     int i;
769     int kver[3] = { -1, -1, -1 };
770     int sock;
771     char *str;
772     struct utsname ut;
773 
774     ret = uname(&ut);
775     if (ret != 0) {
776         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM,
777                  AFALG_R_FAILED_TO_GET_PLATFORM_INFO);
778         return 0;
779     }
780 
781     str = strtok(ut.release, ".");
782     for (i = 0; i < 3 && str != NULL; i++) {
783         kver[i] = atoi(str);
784         str = strtok(NULL, ".");
785     }
786 
787     if (KERNEL_VERSION(kver[0], kver[1], kver[2])
788         < KERNEL_VERSION(K_MAJ, K_MIN1, K_MIN2)) {
789         ALG_ERR("ASYNC AFALG not supported this kernel(%d.%d.%d)\n",
790                  kver[0], kver[1], kver[2]);
791         ALG_ERR("ASYNC AFALG requires kernel version %d.%d.%d or later\n",
792                  K_MAJ, K_MIN1, K_MIN2);
793         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM,
794                  AFALG_R_KERNEL_DOES_NOT_SUPPORT_ASYNC_AFALG);
795         return 0;
796     }
797 
798     /* Test if we can actually create an AF_ALG socket */
799     sock = socket(AF_ALG, SOCK_SEQPACKET, 0);
800     if (sock == -1) {
801         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM, AFALG_R_SOCKET_CREATE_FAILED);
802         return 0;
803     }
804     close(sock);
805 
806     return 1;
807 }
808 
809 # ifdef OPENSSL_NO_DYNAMIC_ENGINE
810 static ENGINE *engine_afalg(void)
811 {
812     ENGINE *ret = ENGINE_new();
813     if (ret == NULL)
814         return NULL;
815     if (!bind_afalg(ret)) {
816         ENGINE_free(ret);
817         return NULL;
818     }
819     return ret;
820 }
821 
822 void engine_load_afalg_int(void)
823 {
824     ENGINE *toadd;
825 
826     if (!afalg_chk_platform())
827         return;
828 
829     toadd = engine_afalg();
830     if (toadd == NULL)
831         return;
832     ENGINE_add(toadd);
833     ENGINE_free(toadd);
834     ERR_clear_error();
835 }
836 # endif
837 
838 static int afalg_init(ENGINE *e)
839 {
840     return 1;
841 }
842 
843 static int afalg_finish(ENGINE *e)
844 {
845     return 1;
846 }
847 
848 static int free_cbc(void)
849 {
850     short unsigned int i;
851     for(i = 0; i < OSSL_NELEM(afalg_cipher_nids); i++) {
852         EVP_CIPHER_meth_free(cbc_handle[i]._hidden);
853         cbc_handle[i]._hidden = NULL;
854     }
855     return 1;
856 }
857 
858 static int afalg_destroy(ENGINE *e)
859 {
860     ERR_unload_AFALG_strings();
861     free_cbc();
862     return 1;
863 }
864 
865 #endif                          /* KERNEL VERSION */
866