xref: /freebsd/crypto/openssl/engines/e_afalg.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 2016-2025 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (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 /* We need to use some deprecated APIs */
11 #define OPENSSL_SUPPRESS_DEPRECATED
12 
13 /* Required for vmsplice */
14 #ifndef _GNU_SOURCE
15 #define _GNU_SOURCE
16 #endif
17 #include <stdio.h>
18 #include <string.h>
19 #include <unistd.h>
20 
21 #include <openssl/engine.h>
22 #include <openssl/async.h>
23 #include <openssl/err.h>
24 #include "internal/nelem.h"
25 
26 #include <sys/socket.h>
27 #include <linux/version.h>
28 #define K_MAJ 4
29 #define K_MIN1 1
30 #define K_MIN2 0
31 #if LINUX_VERSION_CODE < KERNEL_VERSION(K_MAJ, K_MIN1, K_MIN2) || !defined(AF_ALG)
32 #ifndef PEDANTIC
33 #warning "AFALG ENGINE requires Kernel Headers >= 4.1.0"
34 #warning "Skipping Compilation of AFALG engine"
35 #endif
36 void engine_load_afalg_int(void);
engine_load_afalg_int(void)37 void engine_load_afalg_int(void)
38 {
39 }
40 #else
41 
42 #include <linux/if_alg.h>
43 #include <fcntl.h>
44 #include <sys/utsname.h>
45 
46 #include <linux/aio_abi.h>
47 #include <sys/syscall.h>
48 #include <errno.h>
49 
50 /* clang-format off */
51 # include "e_afalg.h"
52 # include "e_afalg_err.c"
53 /* clang-format on */
54 
55 #ifndef SOL_ALG
56 #define SOL_ALG 279
57 #endif
58 
59 #ifdef ALG_ZERO_COPY
60 #ifndef SPLICE_F_GIFT
61 #define SPLICE_F_GIFT (0x08)
62 #endif
63 #endif
64 
65 #define ALG_AES_IV_LEN 16
66 #define ALG_IV_LEN(len) (sizeof(struct af_alg_iv) + (len))
67 #define ALG_OP_TYPE unsigned int
68 #define ALG_OP_LEN (sizeof(ALG_OP_TYPE))
69 
70 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
71 void engine_load_afalg_int(void);
72 #endif
73 
74 /* Local Linkage Functions */
75 static int afalg_init_aio(afalg_aio *aio);
76 static int afalg_fin_cipher_aio(afalg_aio *ptr, int sfd,
77     unsigned char *buf, size_t len);
78 static int afalg_create_sk(afalg_ctx *actx, const char *ciphertype,
79     const char *ciphername);
80 static int afalg_destroy(ENGINE *e);
81 static int afalg_init(ENGINE *e);
82 static int afalg_finish(ENGINE *e);
83 static const EVP_CIPHER *afalg_aes_cbc(int nid);
84 static cbc_handles *get_cipher_handle(int nid);
85 static int afalg_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
86     const int **nids, int nid);
87 static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
88     const unsigned char *iv, int enc);
89 static int afalg_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
90     const unsigned char *in, size_t inl);
91 static int afalg_cipher_cleanup(EVP_CIPHER_CTX *ctx);
92 static int afalg_chk_platform(void);
93 
94 /* Engine Id and Name */
95 static const char *engine_afalg_id = "afalg";
96 static const char *engine_afalg_name = "AFALG engine support";
97 
98 static int afalg_cipher_nids[] = {
99     NID_aes_128_cbc,
100     NID_aes_192_cbc,
101     NID_aes_256_cbc,
102 };
103 
104 static cbc_handles cbc_handle[] = { { AES_KEY_SIZE_128, NULL },
105     { AES_KEY_SIZE_192, NULL },
106     { AES_KEY_SIZE_256, NULL } };
107 
io_setup(unsigned n,aio_context_t * ctx)108 static ossl_inline int io_setup(unsigned n, aio_context_t *ctx)
109 {
110     return syscall(__NR_io_setup, n, ctx);
111 }
112 
eventfd(int n)113 static ossl_inline int eventfd(int n)
114 {
115     return syscall(__NR_eventfd2, n, 0);
116 }
117 
io_destroy(aio_context_t ctx)118 static ossl_inline int io_destroy(aio_context_t ctx)
119 {
120     return syscall(__NR_io_destroy, ctx);
121 }
122 
io_read(aio_context_t ctx,long n,struct iocb ** iocb)123 static ossl_inline int io_read(aio_context_t ctx, long n, struct iocb **iocb)
124 {
125     return syscall(__NR_io_submit, ctx, n, iocb);
126 }
127 
128 /* A version of 'struct timespec' with 32-bit time_t and nanoseconds.  */
129 struct __timespec32 {
130     __kernel_long_t tv_sec;
131     __kernel_long_t tv_nsec;
132 };
133 
io_getevents(aio_context_t ctx,long min,long max,struct io_event * events,struct timespec * timeout)134 static ossl_inline int io_getevents(aio_context_t ctx, long min, long max,
135     struct io_event *events,
136     struct timespec *timeout)
137 {
138 #if defined(__NR_io_pgetevents_time64)
139     /* Check if we are a 32-bit architecture with a 64-bit time_t */
140     if (sizeof(*timeout) != sizeof(struct __timespec32)) {
141         int ret = syscall(__NR_io_pgetevents_time64, ctx, min, max, events,
142             timeout, NULL);
143         if (ret == 0 || errno != ENOSYS)
144             return ret;
145     }
146 #endif
147 
148 #if defined(__NR_io_getevents)
149     if (sizeof(*timeout) == sizeof(struct __timespec32))
150         /*
151          * time_t matches our architecture length, we can just use
152          * __NR_io_getevents
153          */
154         return syscall(__NR_io_getevents, ctx, min, max, events, timeout);
155     else {
156         /*
157          * We don't have __NR_io_pgetevents_time64, but we are using a
158          * 64-bit time_t on a 32-bit architecture. If we can fit the
159          * timeout value in a 32-bit time_t, then let's do that
160          * and then use the __NR_io_getevents syscall.
161          */
162         if (timeout && timeout->tv_sec == (long)timeout->tv_sec) {
163             struct __timespec32 ts32;
164 
165             ts32.tv_sec = (__kernel_long_t)timeout->tv_sec;
166             ts32.tv_nsec = (__kernel_long_t)timeout->tv_nsec;
167 
168             return syscall(__NR_io_getevents, ctx, min, max, events, &ts32);
169         } else {
170             return syscall(__NR_io_getevents, ctx, min, max, events, NULL);
171         }
172     }
173 #endif
174 
175     errno = ENOSYS;
176     return -1;
177 }
178 
afalg_waitfd_cleanup(ASYNC_WAIT_CTX * ctx,const void * key,OSSL_ASYNC_FD waitfd,void * custom)179 static void afalg_waitfd_cleanup(ASYNC_WAIT_CTX *ctx, const void *key,
180     OSSL_ASYNC_FD waitfd, void *custom)
181 {
182     close(waitfd);
183 }
184 
afalg_setup_async_event_notification(afalg_aio * aio)185 static int afalg_setup_async_event_notification(afalg_aio *aio)
186 {
187     ASYNC_JOB *job;
188     ASYNC_WAIT_CTX *waitctx;
189     void *custom = NULL;
190     int ret;
191 
192     if ((job = ASYNC_get_current_job()) != NULL) {
193         /* Async mode */
194         waitctx = ASYNC_get_wait_ctx(job);
195         if (waitctx == NULL) {
196             ALG_WARN("%s(%d): ASYNC_get_wait_ctx error", __FILE__, __LINE__);
197             return 0;
198         }
199         /* Get waitfd from ASYNC_WAIT_CTX if it is already set */
200         ret = ASYNC_WAIT_CTX_get_fd(waitctx, engine_afalg_id,
201             &aio->efd, &custom);
202         if (ret == 0) {
203             /*
204              * waitfd is not set in ASYNC_WAIT_CTX, create a new one
205              * and set it. efd will be signaled when AIO operation completes
206              */
207             aio->efd = eventfd(0);
208             if (aio->efd == -1) {
209                 ALG_PERR("%s(%d): Failed to get eventfd : ", __FILE__,
210                     __LINE__);
211                 AFALGerr(AFALG_F_AFALG_SETUP_ASYNC_EVENT_NOTIFICATION,
212                     AFALG_R_EVENTFD_FAILED);
213                 return 0;
214             }
215             ret = ASYNC_WAIT_CTX_set_wait_fd(waitctx, engine_afalg_id,
216                 aio->efd, custom,
217                 afalg_waitfd_cleanup);
218             if (ret == 0) {
219                 ALG_WARN("%s(%d): Failed to set wait fd", __FILE__, __LINE__);
220                 close(aio->efd);
221                 return 0;
222             }
223             /* make fd non-blocking in async mode */
224             if (fcntl(aio->efd, F_SETFL, O_NONBLOCK) != 0) {
225                 ALG_WARN("%s(%d): Failed to set event fd as NONBLOCKING",
226                     __FILE__, __LINE__);
227             }
228         }
229         aio->mode = MODE_ASYNC;
230     } else {
231         /* Sync mode */
232         aio->efd = eventfd(0);
233         if (aio->efd == -1) {
234             ALG_PERR("%s(%d): Failed to get eventfd : ", __FILE__, __LINE__);
235             AFALGerr(AFALG_F_AFALG_SETUP_ASYNC_EVENT_NOTIFICATION,
236                 AFALG_R_EVENTFD_FAILED);
237             return 0;
238         }
239         aio->mode = MODE_SYNC;
240     }
241     return 1;
242 }
243 
afalg_init_aio(afalg_aio * aio)244 static int afalg_init_aio(afalg_aio *aio)
245 {
246     int r = -1;
247 
248     /* Initialise for AIO */
249     aio->aio_ctx = 0;
250     r = io_setup(MAX_INFLIGHTS, &aio->aio_ctx);
251     if (r < 0) {
252         ALG_PERR("%s(%d): io_setup error : ", __FILE__, __LINE__);
253         AFALGerr(AFALG_F_AFALG_INIT_AIO, AFALG_R_IO_SETUP_FAILED);
254         return 0;
255     }
256 
257     memset(aio->cbt, 0, sizeof(aio->cbt));
258     aio->efd = -1;
259     aio->mode = MODE_UNINIT;
260 
261     return 1;
262 }
263 
afalg_fin_cipher_aio(afalg_aio * aio,int sfd,unsigned char * buf,size_t len)264 static int afalg_fin_cipher_aio(afalg_aio *aio, int sfd, unsigned char *buf,
265     size_t len)
266 {
267     int r;
268     int retry = 0;
269     unsigned int done = 0;
270     struct iocb *cb;
271     struct timespec timeout;
272     struct io_event events[MAX_INFLIGHTS];
273     u_int64_t eval = 0;
274 
275     timeout.tv_sec = 0;
276     timeout.tv_nsec = 0;
277 
278     /* if efd has not been initialised yet do it here */
279     if (aio->mode == MODE_UNINIT) {
280         r = afalg_setup_async_event_notification(aio);
281         if (r == 0)
282             return 0;
283     }
284 
285     cb = &(aio->cbt[0 % MAX_INFLIGHTS]);
286     memset(cb, '\0', sizeof(*cb));
287     cb->aio_fildes = sfd;
288     cb->aio_lio_opcode = IOCB_CMD_PREAD;
289     /*
290      * The pointer has to be converted to unsigned value first to avoid
291      * sign extension on cast to 64 bit value in 32-bit builds
292      */
293     cb->aio_buf = (size_t)buf;
294     cb->aio_offset = 0;
295     cb->aio_data = 0;
296     cb->aio_nbytes = len;
297     cb->aio_flags = IOCB_FLAG_RESFD;
298     cb->aio_resfd = aio->efd;
299 
300     /*
301      * Perform AIO read on AFALG socket, this in turn performs an async
302      * crypto operation in kernel space
303      */
304     r = io_read(aio->aio_ctx, 1, &cb);
305     if (r < 0) {
306         ALG_PWARN("%s(%d): io_read failed : ", __FILE__, __LINE__);
307         return 0;
308     }
309 
310     do {
311         /* While AIO read is being performed pause job */
312         ASYNC_pause_job();
313 
314         /* Check for completion of AIO read */
315         r = read(aio->efd, &eval, sizeof(eval));
316         if (r < 0) {
317             if (errno == EAGAIN || errno == EWOULDBLOCK)
318                 continue;
319             ALG_PERR("%s(%d): read failed for event fd : ", __FILE__, __LINE__);
320             return 0;
321         } else if (r == 0 || eval <= 0) {
322             ALG_WARN("%s(%d): eventfd read %d bytes, eval = %lu\n", __FILE__,
323                 __LINE__, r, eval);
324         }
325         if (eval > 0) {
326 
327 #ifdef OSSL_SANITIZE_MEMORY
328             /*
329              * In a memory sanitiser build, the changes to memory made by the
330              * system call aren't reliably detected.  By initialising the
331              * memory here, the sanitiser is told that they are okay.
332              */
333             memset(events, 0, sizeof(events));
334 #endif
335 
336             /* Get results of AIO read */
337             r = io_getevents(aio->aio_ctx, 1, MAX_INFLIGHTS,
338                 events, &timeout);
339             if (r > 0) {
340                 /*
341                  * events.res indicates the actual status of the operation.
342                  * Handle the error condition first.
343                  */
344                 if (events[0].res < 0) {
345                     /*
346                      * Underlying operation cannot be completed at the time
347                      * of previous submission. Resubmit for the operation.
348                      */
349                     if (events[0].res == -EBUSY && retry++ < 3) {
350                         r = io_read(aio->aio_ctx, 1, &cb);
351                         if (r < 0) {
352                             ALG_PERR("%s(%d): retry %d for io_read failed : ",
353                                 __FILE__, __LINE__, retry);
354                             return 0;
355                         }
356                         continue;
357                     } else {
358                         char strbuf[32];
359                         /*
360                          * sometimes __s64 is defined as long long int
361                          * but on some archs ( like mips64 or powerpc64 ) it's just long int
362                          *
363                          * to be able to use BIO_snprintf() with %lld without warnings
364                          * copy events[0].res to an long long int variable
365                          *
366                          * because long long int should always be at least 64 bit this should work
367                          */
368                         long long int op_ret = events[0].res;
369 
370                         /*
371                          * Retries exceed for -EBUSY or unrecoverable error
372                          * condition for this instance of operation.
373                          */
374                         ALG_WARN("%s(%d): Crypto Operation failed with code %lld\n",
375                             __FILE__, __LINE__, events[0].res);
376                         BIO_snprintf(strbuf, sizeof(strbuf), "%lld", op_ret);
377                         switch (events[0].res) {
378                         case -ENOMEM:
379                             AFALGerr(0, AFALG_R_KERNEL_OP_FAILED);
380                             ERR_add_error_data(3, "-ENOMEM ( code ", strbuf, " )");
381                             break;
382                         default:
383                             AFALGerr(0, AFALG_R_KERNEL_OP_FAILED);
384                             ERR_add_error_data(2, "code ", strbuf);
385                             break;
386                         }
387                         return 0;
388                     }
389                 }
390                 /* Operation successful. */
391                 done = 1;
392             } else if (r < 0) {
393                 ALG_PERR("%s(%d): io_getevents failed : ", __FILE__, __LINE__);
394                 return 0;
395             } else {
396                 ALG_WARN("%s(%d): io_geteventd read 0 bytes\n", __FILE__,
397                     __LINE__);
398             }
399         }
400     } while (!done);
401 
402     return 1;
403 }
404 
afalg_set_op_sk(struct cmsghdr * cmsg,const ALG_OP_TYPE op)405 static ossl_inline void afalg_set_op_sk(struct cmsghdr *cmsg,
406     const ALG_OP_TYPE op)
407 {
408     cmsg->cmsg_level = SOL_ALG;
409     cmsg->cmsg_type = ALG_SET_OP;
410     cmsg->cmsg_len = CMSG_LEN(ALG_OP_LEN);
411     memcpy(CMSG_DATA(cmsg), &op, ALG_OP_LEN);
412 }
413 
afalg_set_iv_sk(struct cmsghdr * cmsg,const unsigned char * iv,const unsigned int len)414 static void afalg_set_iv_sk(struct cmsghdr *cmsg, const unsigned char *iv,
415     const unsigned int len)
416 {
417     struct af_alg_iv *aiv;
418 
419     cmsg->cmsg_level = SOL_ALG;
420     cmsg->cmsg_type = ALG_SET_IV;
421     cmsg->cmsg_len = CMSG_LEN(ALG_IV_LEN(len));
422     aiv = (struct af_alg_iv *)CMSG_DATA(cmsg);
423     aiv->ivlen = len;
424     memcpy(aiv->iv, iv, len);
425 }
426 
afalg_set_key(afalg_ctx * actx,const unsigned char * key,const int klen)427 static ossl_inline int afalg_set_key(afalg_ctx *actx, const unsigned char *key,
428     const int klen)
429 {
430     int ret;
431     ret = setsockopt(actx->bfd, SOL_ALG, ALG_SET_KEY, key, klen);
432     if (ret < 0) {
433         ALG_PERR("%s(%d): Failed to set socket option : ", __FILE__, __LINE__);
434         AFALGerr(AFALG_F_AFALG_SET_KEY, AFALG_R_SOCKET_SET_KEY_FAILED);
435         return 0;
436     }
437     return 1;
438 }
439 
afalg_create_sk(afalg_ctx * actx,const char * ciphertype,const char * ciphername)440 static int afalg_create_sk(afalg_ctx *actx, const char *ciphertype,
441     const char *ciphername)
442 {
443     struct sockaddr_alg sa;
444     int r = -1;
445 
446     actx->bfd = actx->sfd = -1;
447 
448     memset(&sa, 0, sizeof(sa));
449     sa.salg_family = AF_ALG;
450     OPENSSL_strlcpy((char *)sa.salg_type, ciphertype, sizeof(sa.salg_type));
451     OPENSSL_strlcpy((char *)sa.salg_name, ciphername, sizeof(sa.salg_name));
452 
453     actx->bfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
454     if (actx->bfd == -1) {
455         ALG_PERR("%s(%d): Failed to open socket : ", __FILE__, __LINE__);
456         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_CREATE_FAILED);
457         goto err;
458     }
459 
460     r = bind(actx->bfd, (struct sockaddr *)&sa, sizeof(sa));
461     if (r < 0) {
462         ALG_PERR("%s(%d): Failed to bind socket : ", __FILE__, __LINE__);
463         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_BIND_FAILED);
464         goto err;
465     }
466 
467     actx->sfd = accept(actx->bfd, NULL, 0);
468     if (actx->sfd < 0) {
469         ALG_PERR("%s(%d): Socket Accept Failed : ", __FILE__, __LINE__);
470         AFALGerr(AFALG_F_AFALG_CREATE_SK, AFALG_R_SOCKET_ACCEPT_FAILED);
471         goto err;
472     }
473 
474     return 1;
475 
476 err:
477     if (actx->bfd >= 0)
478         close(actx->bfd);
479     if (actx->sfd >= 0)
480         close(actx->sfd);
481     actx->bfd = actx->sfd = -1;
482     return 0;
483 }
484 
afalg_start_cipher_sk(afalg_ctx * actx,const unsigned char * in,size_t inl,const unsigned char * iv,unsigned int enc)485 static int afalg_start_cipher_sk(afalg_ctx *actx, const unsigned char *in,
486     size_t inl, const unsigned char *iv,
487     unsigned int enc)
488 {
489     struct msghdr msg;
490     struct cmsghdr *cmsg;
491     struct iovec iov;
492     ssize_t sbytes;
493 #ifdef ALG_ZERO_COPY
494     int ret;
495 #endif
496     char cbuf[CMSG_SPACE(ALG_IV_LEN(ALG_AES_IV_LEN)) + CMSG_SPACE(ALG_OP_LEN)];
497 
498     memset(&msg, 0, sizeof(msg));
499     memset(cbuf, 0, sizeof(cbuf));
500     msg.msg_control = cbuf;
501     msg.msg_controllen = sizeof(cbuf);
502 
503     /*
504      * cipher direction (i.e. encrypt or decrypt) and iv are sent to the
505      * kernel as part of sendmsg()'s ancillary data
506      */
507     cmsg = CMSG_FIRSTHDR(&msg);
508     afalg_set_op_sk(cmsg, enc);
509     cmsg = CMSG_NXTHDR(&msg, cmsg);
510     afalg_set_iv_sk(cmsg, iv, ALG_AES_IV_LEN);
511 
512     /* iov that describes input data */
513     iov.iov_base = (unsigned char *)in;
514     iov.iov_len = inl;
515 
516     msg.msg_flags = MSG_MORE;
517 
518 #ifdef ALG_ZERO_COPY
519     /*
520      * ZERO_COPY mode
521      * Works best when buffer is 4k aligned
522      * OPENS: out of place processing (i.e. out != in)
523      */
524 
525     /* Input data is not sent as part of call to sendmsg() */
526     msg.msg_iovlen = 0;
527     msg.msg_iov = NULL;
528 
529     /* Sendmsg() sends iv and cipher direction to the kernel */
530     sbytes = sendmsg(actx->sfd, &msg, 0);
531     if (sbytes < 0) {
532         ALG_PERR("%s(%d): sendmsg failed for zero copy cipher operation : ",
533             __FILE__, __LINE__);
534         return 0;
535     }
536 
537     /*
538      * vmsplice and splice are used to pin the user space input buffer for
539      * kernel space processing avoiding copies from user to kernel space
540      */
541     ret = vmsplice(actx->zc_pipe[1], &iov, 1, SPLICE_F_GIFT);
542     if (ret < 0) {
543         ALG_PERR("%s(%d): vmsplice failed : ", __FILE__, __LINE__);
544         return 0;
545     }
546 
547     ret = splice(actx->zc_pipe[0], NULL, actx->sfd, NULL, inl, 0);
548     if (ret < 0) {
549         ALG_PERR("%s(%d): splice failed : ", __FILE__, __LINE__);
550         return 0;
551     }
552 #else
553     msg.msg_iovlen = 1;
554     msg.msg_iov = &iov;
555 
556     /* Sendmsg() sends iv, cipher direction and input data to the kernel */
557     sbytes = sendmsg(actx->sfd, &msg, 0);
558     if (sbytes < 0) {
559         ALG_PERR("%s(%d): sendmsg failed for cipher operation : ", __FILE__,
560             __LINE__);
561         return 0;
562     }
563 
564     if (sbytes != (ssize_t)inl) {
565         ALG_WARN("Cipher operation send bytes %zd != inlen %zd\n", sbytes,
566             inl);
567         return 0;
568     }
569 #endif
570 
571     return 1;
572 }
573 
afalg_cipher_init(EVP_CIPHER_CTX * ctx,const unsigned char * key,const unsigned char * iv,int enc)574 static int afalg_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
575     const unsigned char *iv, int enc)
576 {
577     int ciphertype;
578     int ret, len;
579     afalg_ctx *actx;
580     const char *ciphername;
581 
582     if (ctx == NULL || key == NULL) {
583         ALG_WARN("%s(%d): Null Parameter\n", __FILE__, __LINE__);
584         return 0;
585     }
586 
587     if (EVP_CIPHER_CTX_get0_cipher(ctx) == NULL) {
588         ALG_WARN("%s(%d): Cipher object NULL\n", __FILE__, __LINE__);
589         return 0;
590     }
591 
592     actx = EVP_CIPHER_CTX_get_cipher_data(ctx);
593     if (actx == NULL) {
594         ALG_WARN("%s(%d): Cipher data NULL\n", __FILE__, __LINE__);
595         return 0;
596     }
597 
598     ciphertype = EVP_CIPHER_CTX_get_nid(ctx);
599     switch (ciphertype) {
600     case NID_aes_128_cbc:
601     case NID_aes_192_cbc:
602     case NID_aes_256_cbc:
603         ciphername = "cbc(aes)";
604         break;
605     default:
606         ALG_WARN("%s(%d): Unsupported Cipher type %d\n", __FILE__, __LINE__,
607             ciphertype);
608         return 0;
609     }
610 
611     if (ALG_AES_IV_LEN != EVP_CIPHER_CTX_get_iv_length(ctx)) {
612         ALG_WARN("%s(%d): Unsupported IV length :%d\n", __FILE__, __LINE__,
613             EVP_CIPHER_CTX_get_iv_length(ctx));
614         return 0;
615     }
616 
617     /* Setup AFALG socket for crypto processing */
618     ret = afalg_create_sk(actx, "skcipher", ciphername);
619     if (ret < 1)
620         return 0;
621 
622     if ((len = EVP_CIPHER_CTX_get_key_length(ctx)) <= 0)
623         goto err;
624     ret = afalg_set_key(actx, key, len);
625     if (ret < 1)
626         goto err;
627 
628     /* Setup AIO ctx to allow async AFALG crypto processing */
629     if (afalg_init_aio(&actx->aio) == 0)
630         goto err;
631 
632 #ifdef ALG_ZERO_COPY
633     pipe(actx->zc_pipe);
634 #endif
635 
636     actx->init_done = MAGIC_INIT_NUM;
637 
638     return 1;
639 
640 err:
641     close(actx->sfd);
642     close(actx->bfd);
643     return 0;
644 }
645 
afalg_do_cipher(EVP_CIPHER_CTX * ctx,unsigned char * out,const unsigned char * in,size_t inl)646 static int afalg_do_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
647     const unsigned char *in, size_t inl)
648 {
649     afalg_ctx *actx;
650     int ret;
651     char nxtiv[ALG_AES_IV_LEN] = { 0 };
652 
653     if (ctx == NULL || out == NULL || in == NULL) {
654         ALG_WARN("NULL parameter passed to function %s(%d)\n", __FILE__,
655             __LINE__);
656         return 0;
657     }
658 
659     actx = (afalg_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
660     if (actx == NULL || actx->init_done != MAGIC_INIT_NUM) {
661         ALG_WARN("%s afalg ctx passed\n",
662             ctx == NULL ? "NULL" : "Uninitialised");
663         return 0;
664     }
665 
666     /*
667      * set iv now for decrypt operation as the input buffer can be
668      * overwritten for inplace operation where in = out.
669      */
670     if (EVP_CIPHER_CTX_is_encrypting(ctx) == 0) {
671         memcpy(nxtiv, in + (inl - ALG_AES_IV_LEN), ALG_AES_IV_LEN);
672     }
673 
674     /* Send input data to kernel space */
675     ret = afalg_start_cipher_sk(actx, (unsigned char *)in, inl,
676         EVP_CIPHER_CTX_iv(ctx),
677         EVP_CIPHER_CTX_is_encrypting(ctx));
678     if (ret < 1) {
679         return 0;
680     }
681 
682     /* Perform async crypto operation in kernel space */
683     ret = afalg_fin_cipher_aio(&actx->aio, actx->sfd, out, inl);
684     if (ret < 1)
685         return 0;
686 
687     if (EVP_CIPHER_CTX_is_encrypting(ctx)) {
688         memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), out + (inl - ALG_AES_IV_LEN),
689             ALG_AES_IV_LEN);
690     } else {
691         memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), nxtiv, ALG_AES_IV_LEN);
692     }
693 
694     return 1;
695 }
696 
afalg_cipher_cleanup(EVP_CIPHER_CTX * ctx)697 static int afalg_cipher_cleanup(EVP_CIPHER_CTX *ctx)
698 {
699     afalg_ctx *actx;
700 
701     if (ctx == NULL) {
702         ALG_WARN("NULL parameter passed to function %s(%d)\n", __FILE__,
703             __LINE__);
704         return 0;
705     }
706 
707     actx = (afalg_ctx *)EVP_CIPHER_CTX_get_cipher_data(ctx);
708     if (actx == NULL || actx->init_done != MAGIC_INIT_NUM)
709         return 1;
710 
711     close(actx->sfd);
712     close(actx->bfd);
713 #ifdef ALG_ZERO_COPY
714     close(actx->zc_pipe[0]);
715     close(actx->zc_pipe[1]);
716 #endif
717     /* close efd in sync mode, async mode is closed in afalg_waitfd_cleanup() */
718     if (actx->aio.mode == MODE_SYNC)
719         close(actx->aio.efd);
720     io_destroy(actx->aio.aio_ctx);
721 
722     return 1;
723 }
724 
get_cipher_handle(int nid)725 static cbc_handles *get_cipher_handle(int nid)
726 {
727     switch (nid) {
728     case NID_aes_128_cbc:
729         return &cbc_handle[AES_CBC_128];
730     case NID_aes_192_cbc:
731         return &cbc_handle[AES_CBC_192];
732     case NID_aes_256_cbc:
733         return &cbc_handle[AES_CBC_256];
734     default:
735         return NULL;
736     }
737 }
738 
afalg_aes_cbc(int nid)739 static const EVP_CIPHER *afalg_aes_cbc(int nid)
740 {
741     cbc_handles *cipher_handle = get_cipher_handle(nid);
742 
743     if (cipher_handle == NULL)
744         return NULL;
745     if (cipher_handle->_hidden == NULL
746         && ((cipher_handle->_hidden = EVP_CIPHER_meth_new(nid,
747                  AES_BLOCK_SIZE,
748                  cipher_handle->key_size))
749                 == NULL
750             || !EVP_CIPHER_meth_set_iv_length(cipher_handle->_hidden,
751                 AES_IV_LEN)
752             || !EVP_CIPHER_meth_set_flags(cipher_handle->_hidden,
753                 EVP_CIPH_CBC_MODE | EVP_CIPH_FLAG_DEFAULT_ASN1)
754             || !EVP_CIPHER_meth_set_init(cipher_handle->_hidden,
755                 afalg_cipher_init)
756             || !EVP_CIPHER_meth_set_do_cipher(cipher_handle->_hidden,
757                 afalg_do_cipher)
758             || !EVP_CIPHER_meth_set_cleanup(cipher_handle->_hidden,
759                 afalg_cipher_cleanup)
760             || !EVP_CIPHER_meth_set_impl_ctx_size(cipher_handle->_hidden,
761                 sizeof(afalg_ctx)))) {
762         EVP_CIPHER_meth_free(cipher_handle->_hidden);
763         cipher_handle->_hidden = NULL;
764     }
765     return cipher_handle->_hidden;
766 }
767 
afalg_ciphers(ENGINE * e,const EVP_CIPHER ** cipher,const int ** nids,int nid)768 static int afalg_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
769     const int **nids, int nid)
770 {
771     int r = 1;
772 
773     if (cipher == NULL) {
774         *nids = afalg_cipher_nids;
775         return OSSL_NELEM(afalg_cipher_nids);
776     }
777 
778     switch (nid) {
779     case NID_aes_128_cbc:
780     case NID_aes_192_cbc:
781     case NID_aes_256_cbc:
782         *cipher = afalg_aes_cbc(nid);
783         break;
784     default:
785         *cipher = NULL;
786         r = 0;
787     }
788     return r;
789 }
790 
bind_afalg(ENGINE * e)791 static int bind_afalg(ENGINE *e)
792 {
793     /* Ensure the afalg error handling is set up */
794     unsigned short i;
795     ERR_load_AFALG_strings();
796 
797     if (!ENGINE_set_id(e, engine_afalg_id)
798         || !ENGINE_set_name(e, engine_afalg_name)
799         || !ENGINE_set_destroy_function(e, afalg_destroy)
800         || !ENGINE_set_init_function(e, afalg_init)
801         || !ENGINE_set_finish_function(e, afalg_finish)) {
802         AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
803         return 0;
804     }
805 
806     /*
807      * Create _hidden_aes_xxx_cbc by calling afalg_aes_xxx_cbc
808      * now, as bind_aflag can only be called by one thread at a
809      * time.
810      */
811     for (i = 0; i < OSSL_NELEM(afalg_cipher_nids); i++) {
812         if (afalg_aes_cbc(afalg_cipher_nids[i]) == NULL) {
813             AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
814             return 0;
815         }
816     }
817 
818     if (!ENGINE_set_ciphers(e, afalg_ciphers)) {
819         AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
820         return 0;
821     }
822 
823     return 1;
824 }
825 
826 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
bind_helper(ENGINE * e,const char * id)827 static int bind_helper(ENGINE *e, const char *id)
828 {
829     if (id && (strcmp(id, engine_afalg_id) != 0))
830         return 0;
831 
832     if (!afalg_chk_platform())
833         return 0;
834 
835     if (!bind_afalg(e)) {
836         afalg_destroy(e);
837         return 0;
838     }
839     return 1;
840 }
841 
842 IMPLEMENT_DYNAMIC_CHECK_FN()
IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)843 IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
844 #endif
845 
846 static int afalg_chk_platform(void)
847 {
848     int ret;
849     int i;
850     int kver[3] = { -1, -1, -1 };
851     int sock;
852     char *str;
853     struct utsname ut;
854 
855     ret = uname(&ut);
856     if (ret != 0) {
857         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM,
858             AFALG_R_FAILED_TO_GET_PLATFORM_INFO);
859         return 0;
860     }
861 
862     str = strtok(ut.release, ".");
863     for (i = 0; i < 3 && str != NULL; i++) {
864         kver[i] = atoi(str);
865         str = strtok(NULL, ".");
866     }
867 
868     if (KERNEL_VERSION(kver[0], kver[1], kver[2])
869         < KERNEL_VERSION(K_MAJ, K_MIN1, K_MIN2)) {
870         ALG_ERR("ASYNC AFALG not supported this kernel(%d.%d.%d)\n",
871             kver[0], kver[1], kver[2]);
872         ALG_ERR("ASYNC AFALG requires kernel version %d.%d.%d or later\n",
873             K_MAJ, K_MIN1, K_MIN2);
874         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM,
875             AFALG_R_KERNEL_DOES_NOT_SUPPORT_ASYNC_AFALG);
876         return 0;
877     }
878 
879     /* Test if we can actually create an AF_ALG socket */
880     sock = socket(AF_ALG, SOCK_SEQPACKET, 0);
881     if (sock == -1) {
882         AFALGerr(AFALG_F_AFALG_CHK_PLATFORM, AFALG_R_SOCKET_CREATE_FAILED);
883         return 0;
884     }
885     close(sock);
886 
887     return 1;
888 }
889 
890 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
engine_afalg(void)891 static ENGINE *engine_afalg(void)
892 {
893     ENGINE *ret = ENGINE_new();
894     if (ret == NULL)
895         return NULL;
896     if (!bind_afalg(ret)) {
897         ENGINE_free(ret);
898         return NULL;
899     }
900     return ret;
901 }
902 
engine_load_afalg_int(void)903 void engine_load_afalg_int(void)
904 {
905     ENGINE *toadd;
906 
907     if (!afalg_chk_platform())
908         return;
909 
910     toadd = engine_afalg();
911     if (toadd == NULL)
912         return;
913     ERR_set_mark();
914     ENGINE_add(toadd);
915     /*
916      * If the "add" worked, it gets a structural reference. So either way, we
917      * release our just-created reference.
918      */
919     ENGINE_free(toadd);
920     /*
921      * If the "add" didn't work, it was probably a conflict because it was
922      * already added (eg. someone calling ENGINE_load_blah then calling
923      * ENGINE_load_builtin_engines() perhaps).
924      */
925     ERR_pop_to_mark();
926 }
927 #endif
928 
afalg_init(ENGINE * e)929 static int afalg_init(ENGINE *e)
930 {
931     return 1;
932 }
933 
afalg_finish(ENGINE * e)934 static int afalg_finish(ENGINE *e)
935 {
936     return 1;
937 }
938 
free_cbc(void)939 static int free_cbc(void)
940 {
941     short unsigned int i;
942     for (i = 0; i < OSSL_NELEM(afalg_cipher_nids); i++) {
943         EVP_CIPHER_meth_free(cbc_handle[i]._hidden);
944         cbc_handle[i]._hidden = NULL;
945     }
946     return 1;
947 }
948 
afalg_destroy(ENGINE * e)949 static int afalg_destroy(ENGINE *e)
950 {
951     ERR_unload_AFALG_strings();
952     free_cbc();
953     return 1;
954 }
955 
956 #endif /* KERNEL VERSION */
957