1 /*
2 * f2fscrypt.c - f2fs encryption management utility
3 *
4 * Authors: Kinglong Mee <kinglongmee@gmail.com>
5 *
6 * Copied from e4crypt that for ext4 filesystem.
7 * Authors: Michael Halcrow <mhalcrow@google.com>,
8 * Ildar Muslukhov <ildarm@google.com>
9 */
10
11 #ifndef _LARGEFILE_SOURCE
12 #define _LARGEFILE_SOURCE
13 #endif
14
15 #ifndef _LARGEFILE64_SOURCE
16 #define _LARGEFILE64_SOURCE
17 #endif
18
19 #ifndef _GNU_SOURCE
20 #define _GNU_SOURCE
21 #endif
22
23 #include "config.h"
24 #include <assert.h>
25 #include <errno.h>
26 #include <getopt.h>
27 #include <dirent.h>
28 #include <errno.h>
29 #include <stdarg.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #ifdef HAVE_MNTENT_H
34 #include <mntent.h>
35 #endif
36 #include <sys/ioctl.h>
37 #include <sys/stat.h>
38 #include <sys/types.h>
39 #include <fcntl.h>
40 #include <termios.h>
41 #include <unistd.h>
42 #include <signal.h>
43 #ifdef __KERNEL__
44 #include <linux/fs.h>
45 #endif
46 #include <uuid/uuid.h>
47
48 #if !defined(HAVE_ADD_KEY) || !defined(HAVE_KEYCTL)
49 #include <sys/syscall.h>
50 #endif
51 #ifdef HAVE_SYS_KEY_H
52 #include <sys/key.h>
53 #endif
54 #include <f2fs_fs.h>
55
56 #define F2FS_MAX_KEY_SIZE 64
57 #define F2FS_MAX_PASSPHRASE_SIZE 1024
58 #define F2FS_MAX_SALT_SIZE 256
59
60 /* Encryption algorithms, key size and key reference len */
61 #define F2FS_ENCRYPTION_MODE_INVALID 0
62 #define F2FS_ENCRYPTION_MODE_AES_256_XTS 1
63 #define F2FS_ENCRYPTION_MODE_AES_256_GCM 2
64 #define F2FS_ENCRYPTION_MODE_AES_256_CBC 3
65 #define F2FS_ENCRYPTION_MODE_AES_256_CTS 4
66
67 #define F2FS_AES_256_XTS_KEY_SIZE 64
68 #define F2FS_AES_256_GCM_KEY_SIZE 32
69 #define F2FS_AES_256_CBC_KEY_SIZE 32
70 #define F2FS_AES_256_CTS_KEY_SIZE 32
71 #define F2FS_MAX_KEY_SIZE 64
72
73 /* Password derivation constants */
74 #define F2FS_MAX_PASSPHRASE_SIZE 1024
75 #define F2FS_MAX_SALT_SIZE 256
76 #define F2FS_PBKDF2_ITERATIONS 0xFFFF
77
78 /* special process keyring shortcut IDs */
79 #define KEY_SPEC_THREAD_KEYRING -1
80 #define KEY_SPEC_PROCESS_KEYRING -2
81 #define KEY_SPEC_SESSION_KEYRING -3
82 #define KEY_SPEC_USER_KEYRING -4
83 #define KEY_SPEC_USER_SESSION_KEYRING -5
84 #define KEY_SPEC_GROUP_KEYRING -6
85
86 #define KEYCTL_GET_KEYRING_ID 0
87 #define KEYCTL_JOIN_SESSION_KEYRING 1
88 #define KEYCTL_DESCRIBE 6
89 #define KEYCTL_SEARCH 10
90 #define KEYCTL_SESSION_TO_PARENT 18
91
92 /*
93 * File system encryption support
94 */
95 /* Policy provided via an ioctl on the topmost directory */
96 #define F2FS_KEY_DESCRIPTOR_SIZE 8
97 #define F2FS_KEY_REF_STR_BUF_SIZE ((F2FS_KEY_DESCRIPTOR_SIZE * 2) + 1)
98
99 struct f2fs_fscrypt_policy {
100 __u8 version;
101 __u8 contents_encryption_mode;
102 __u8 filenames_encryption_mode;
103 __u8 flags;
104 __u8 master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
105 } __attribute__((packed));
106
107 #define F2FS_IOC_SET_ENCRYPTION_POLICY _IOR('f', 19, struct f2fs_fscrypt_policy)
108 #define F2FS_IOC_GET_ENCRYPTION_PWSALT _IOW('f', 20, __u8[16])
109 #define F2FS_IOC_GET_ENCRYPTION_POLICY _IOW('f', 21, struct f2fs_fscrypt_policy)
110
111 typedef int32_t key_serial_t;
112
113
114
115 #define OPT_VERBOSE 0x0001
116 #define OPT_QUIET 0x0002
117
118 struct f2fs_encryption_key {
119 __u32 mode;
120 char raw[F2FS_MAX_KEY_SIZE];
121 __u32 size;
122 } __attribute__((__packed__));
123
124 int options;
125
126 extern void f2fs_sha512(const unsigned char *in, unsigned long in_size,
127 unsigned char *out);
128
129 #if !defined(HAVE_KEYCTL)
keyctl(int cmd,...)130 static long keyctl(int cmd, ...)
131 {
132 va_list va;
133 unsigned long arg2, arg3, arg4, arg5;
134
135 va_start(va, cmd);
136 arg2 = va_arg(va, unsigned long);
137 arg3 = va_arg(va, unsigned long);
138 arg4 = va_arg(va, unsigned long);
139 arg5 = va_arg(va, unsigned long);
140 va_end(va);
141 return syscall(__NR_keyctl, cmd, arg2, arg3, arg4, arg5);
142 }
143 #endif
144
145 #if !defined(HAVE_ADD_KEY)
add_key(const char * type,const char * description,const void * payload,size_t plen,key_serial_t keyring)146 static key_serial_t add_key(const char *type, const char *description,
147 const void *payload, size_t plen,
148 key_serial_t keyring)
149 {
150 return syscall(__NR_add_key, type, description, payload,
151 plen, keyring);
152 }
153 #endif
154
155 static const unsigned char *hexchars = (const unsigned char *) "0123456789abcdef";
156 static const size_t hexchars_size = 16;
157
158 #define SHA512_LENGTH 64
159 #define F2FS_KEY_TYPE_LOGON "logon"
160 #define F2FS_KEY_DESC_PREFIX "f2fs:"
161 #define F2FS_KEY_DESC_PREFIX_SIZE 5
162
int_log2(int arg)163 static int int_log2(int arg)
164 {
165 int l = 0;
166
167 arg >>= 1;
168 while (arg) {
169 l++;
170 arg >>= 1;
171 }
172 return l;
173 }
174
validate_paths(int argc,char * argv[],int path_start_index)175 static void validate_paths(int argc, char *argv[], int path_start_index)
176 {
177 int x;
178 int valid = 1;
179 struct stat st;
180
181 for (x = path_start_index; x < argc; x++) {
182 int ret = access(argv[x], W_OK);
183 if (ret) {
184 invalid:
185 perror(argv[x]);
186 valid = 0;
187 continue;
188 }
189 ret = stat(argv[x], &st);
190 if (ret < 0)
191 goto invalid;
192 if (!S_ISDIR(st.st_mode)) {
193 fprintf(stderr, "%s is not a directory\n", argv[x]);
194 goto invalid;
195 }
196 }
197 if (!valid)
198 exit(1);
199 }
200
hex2byte(const char * hex,size_t hex_size,unsigned char * bytes,size_t bytes_size)201 static int hex2byte(const char *hex, size_t hex_size, unsigned char *bytes,
202 size_t bytes_size)
203 {
204 size_t x;
205 unsigned char *h, *l;
206
207 if (hex_size % 2)
208 return -EINVAL;
209 for (x = 0; x < hex_size; x += 2) {
210 h = memchr(hexchars, hex[x], hexchars_size);
211 if (!h)
212 return -EINVAL;
213 l = memchr(hexchars, hex[x + 1], hexchars_size);
214 if (!l)
215 return -EINVAL;
216 if ((x >> 1) >= bytes_size)
217 return -EINVAL;
218 bytes[x >> 1] = (((unsigned char)(h - hexchars) << 4) +
219 (unsigned char)(l - hexchars));
220 }
221 return 0;
222 }
223
224 /*
225 * Salt handling
226 */
227 struct salt {
228 unsigned char *salt;
229 char key_ref_str[F2FS_KEY_REF_STR_BUF_SIZE];
230 unsigned char key_desc[F2FS_KEY_DESCRIPTOR_SIZE];
231 unsigned char key[F2FS_MAX_KEY_SIZE];
232 size_t salt_len;
233 };
234 struct salt *salt_list;
235 unsigned num_salt;
236 unsigned max_salt;
237 char in_passphrase[F2FS_MAX_PASSPHRASE_SIZE];
238
find_by_salt(unsigned char * salt,size_t salt_len)239 static struct salt *find_by_salt(unsigned char *salt, size_t salt_len)
240 {
241 unsigned int i;
242 struct salt *p;
243
244 for (i = 0, p = salt_list; i < num_salt; i++, p++)
245 if ((p->salt_len == salt_len) &&
246 !memcmp(p->salt, salt, salt_len))
247 return p;
248 return NULL;
249 }
250
add_salt(unsigned char * salt,size_t salt_len)251 static void add_salt(unsigned char *salt, size_t salt_len)
252 {
253 if (find_by_salt(salt, salt_len))
254 return;
255 if (num_salt >= max_salt) {
256 max_salt = num_salt + 10;
257 salt_list = realloc(salt_list, max_salt * sizeof(struct salt));
258 if (!salt_list) {
259 fprintf(stderr, "Couldn't allocate salt list\n");
260 exit(1);
261 }
262 }
263 salt_list[num_salt].salt = salt;
264 salt_list[num_salt].salt_len = salt_len;
265 num_salt++;
266 }
267
clear_secrets(void)268 static void clear_secrets(void)
269 {
270 if (salt_list) {
271 memset(salt_list, 0, sizeof(struct salt) * max_salt);
272 free(salt_list);
273 salt_list = NULL;
274 }
275 memset(in_passphrase, 0, sizeof(in_passphrase));
276 }
277
die_signal_handler(int UNUSED (signum),siginfo_t * UNUSED (siginfo),void * UNUSED (context))278 static void die_signal_handler(int UNUSED(signum),
279 siginfo_t *UNUSED(siginfo), void *UNUSED(context))
280 {
281 clear_secrets();
282 exit(-1);
283 }
284
sigcatcher_setup(void)285 static void sigcatcher_setup(void)
286 {
287 struct sigaction sa;
288
289 memset(&sa, 0, sizeof(struct sigaction));
290 sa.sa_sigaction = die_signal_handler;
291 sa.sa_flags = SA_SIGINFO;
292
293 sigaction(SIGHUP, &sa, 0);
294 sigaction(SIGINT, &sa, 0);
295 sigaction(SIGQUIT, &sa, 0);
296 sigaction(SIGFPE, &sa, 0);
297 sigaction(SIGILL, &sa, 0);
298 sigaction(SIGBUS, &sa, 0);
299 sigaction(SIGSEGV, &sa, 0);
300 sigaction(SIGABRT, &sa, 0);
301 sigaction(SIGPIPE, &sa, 0);
302 sigaction(SIGALRM, &sa, 0);
303 sigaction(SIGTERM, &sa, 0);
304 sigaction(SIGUSR1, &sa, 0);
305 sigaction(SIGUSR2, &sa, 0);
306 sigaction(SIGPOLL, &sa, 0);
307 sigaction(SIGPROF, &sa, 0);
308 sigaction(SIGSYS, &sa, 0);
309 sigaction(SIGTRAP, &sa, 0);
310 sigaction(SIGVTALRM, &sa, 0);
311 sigaction(SIGXCPU, &sa, 0);
312 sigaction(SIGXFSZ, &sa, 0);
313 }
314
315
316 #define PARSE_FLAGS_NOTSUPP_OK 0x0001
317 #define PARSE_FLAGS_FORCE_FN 0x0002
318
parse_salt(char * salt_str,int flags)319 static void parse_salt(char *salt_str, int flags)
320 {
321 unsigned char buf[F2FS_MAX_SALT_SIZE];
322 char *cp = salt_str;
323 unsigned char *salt_buf;
324 int fd, ret, salt_len = 0;
325
326 if (flags & PARSE_FLAGS_FORCE_FN)
327 goto salt_from_filename;
328 if (strncmp(cp, "s:", 2) == 0) {
329 cp += 2;
330 salt_len = strlen(cp);
331 if (salt_len >= F2FS_MAX_SALT_SIZE)
332 goto invalid_salt;
333 strncpy((char *) buf, cp, sizeof(buf));
334 } else if (cp[0] == '/') {
335 salt_from_filename:
336 fd = open(cp, O_RDONLY | O_DIRECTORY);
337 if (fd == -1 && errno == ENOTDIR)
338 fd = open(cp, O_RDONLY);
339 if (fd == -1) {
340 perror(cp);
341 exit(1);
342 }
343 ret = ioctl(fd, F2FS_IOC_GET_ENCRYPTION_PWSALT, &buf);
344 close(fd);
345 if (ret < 0) {
346 if (flags & PARSE_FLAGS_NOTSUPP_OK)
347 return;
348 perror("F2FS_IOC_GET_ENCRYPTION_PWSALT");
349 exit(1);
350 }
351 if (options & OPT_VERBOSE) {
352 char tmp[80];
353 uuid_unparse(buf, tmp);
354 printf("%s has pw salt %s\n", cp, tmp);
355 }
356 salt_len = 16;
357 } else if (strncmp(cp, "f:", 2) == 0) {
358 cp += 2;
359 goto salt_from_filename;
360 } else if (strncmp(cp, "0x", 2) == 0) {
361 unsigned char *h, *l;
362
363 cp += 2;
364 if (strlen(cp) & 1)
365 goto invalid_salt;
366 while (*cp) {
367 if (salt_len >= F2FS_MAX_SALT_SIZE)
368 goto invalid_salt;
369 h = memchr(hexchars, *cp++, hexchars_size);
370 l = memchr(hexchars, *cp++, hexchars_size);
371 if (!h || !l)
372 goto invalid_salt;
373 buf[salt_len++] =
374 (((unsigned char)(h - hexchars) << 4) +
375 (unsigned char)(l - hexchars));
376 }
377 } else if (uuid_parse(cp, buf) == 0) {
378 salt_len = 16;
379 } else {
380 invalid_salt:
381 fprintf(stderr, "Invalid salt: %s\n", salt_str);
382 exit(1);
383 }
384 salt_buf = malloc(salt_len);
385 if (!salt_buf) {
386 fprintf(stderr, "Couldn't allocate salt\n");
387 exit(1);
388 }
389 memcpy(salt_buf, buf, salt_len);
390 add_salt(salt_buf, salt_len);
391 }
392
set_policy(struct salt * set_salt,int pad,int argc,char * argv[],int path_start_index)393 static void set_policy(struct salt *set_salt, int pad,
394 int argc, char *argv[], int path_start_index)
395 {
396 struct salt *salt;
397 struct f2fs_fscrypt_policy policy;
398 uuid_t uu;
399 int fd;
400 int x;
401 int rc;
402
403 if ((pad != 4) && (pad != 8) &&
404 (pad != 16) && (pad != 32)) {
405 fprintf(stderr, "Invalid padding %d\n", pad);
406 exit(1);
407 }
408
409 for (x = path_start_index; x < argc; x++) {
410 fd = open(argv[x], O_DIRECTORY);
411 if (fd == -1) {
412 perror(argv[x]);
413 exit(1);
414 }
415 if (set_salt)
416 salt = set_salt;
417 else {
418 if (ioctl(fd, F2FS_IOC_GET_ENCRYPTION_PWSALT,
419 &uu) < 0) {
420 perror("F2FS_IOC_GET_ENCRYPTION_PWSALT");
421 exit(1);
422 }
423 salt = find_by_salt(uu, sizeof(uu));
424 if (!salt) {
425 fprintf(stderr, "Couldn't find salt!?!\n");
426 exit(1);
427 }
428 }
429 policy.version = 0;
430 policy.contents_encryption_mode =
431 F2FS_ENCRYPTION_MODE_AES_256_XTS;
432 policy.filenames_encryption_mode =
433 F2FS_ENCRYPTION_MODE_AES_256_CTS;
434 policy.flags = int_log2(pad >> 2);
435 memcpy(policy.master_key_descriptor, salt->key_desc,
436 F2FS_KEY_DESCRIPTOR_SIZE);
437 rc = ioctl(fd, F2FS_IOC_SET_ENCRYPTION_POLICY, &policy);
438 close(fd);
439 if (rc) {
440 printf("Error [%s] setting policy.\nThe key descriptor "
441 "[%s] may not match the existing encryption "
442 "context for directory [%s].\n",
443 strerror(errno), salt->key_ref_str, argv[x]);
444 continue;
445 }
446 printf("Key with descriptor [%s] applied to %s.\n",
447 salt->key_ref_str, argv[x]);
448 }
449 }
450
pbkdf2_sha512(const char * passphrase,struct salt * salt,unsigned int count,unsigned char derived_key[F2FS_MAX_KEY_SIZE])451 static void pbkdf2_sha512(const char *passphrase, struct salt *salt,
452 unsigned int count,
453 unsigned char derived_key[F2FS_MAX_KEY_SIZE])
454 {
455 size_t passphrase_size = strlen(passphrase);
456 unsigned char buf[SHA512_LENGTH + F2FS_MAX_PASSPHRASE_SIZE] = {0};
457 unsigned char tempbuf[SHA512_LENGTH] = {0};
458 char final[SHA512_LENGTH] = {0};
459 unsigned char saltbuf[F2FS_MAX_SALT_SIZE + F2FS_MAX_PASSPHRASE_SIZE] = {0};
460 int actual_buf_len = SHA512_LENGTH + passphrase_size;
461 int actual_saltbuf_len = F2FS_MAX_SALT_SIZE + passphrase_size;
462 unsigned int x, y;
463 __u32 *final_u32 = (__u32 *)final;
464 __u32 *temp_u32 = (__u32 *)tempbuf;
465
466 if (passphrase_size > F2FS_MAX_PASSPHRASE_SIZE) {
467 printf("Passphrase size is %zd; max is %d.\n", passphrase_size,
468 F2FS_MAX_PASSPHRASE_SIZE);
469 exit(1);
470 }
471 if (salt->salt_len > F2FS_MAX_SALT_SIZE) {
472 printf("Salt size is %zd; max is %d.\n", salt->salt_len,
473 F2FS_MAX_SALT_SIZE);
474 exit(1);
475 }
476 assert(F2FS_MAX_KEY_SIZE <= SHA512_LENGTH);
477
478 memcpy(saltbuf, salt->salt, salt->salt_len);
479 memcpy(&saltbuf[F2FS_MAX_SALT_SIZE], passphrase, passphrase_size);
480
481 memcpy(&buf[SHA512_LENGTH], passphrase, passphrase_size);
482
483 for (x = 0; x < count; ++x) {
484 if (x == 0) {
485 f2fs_sha512(saltbuf, actual_saltbuf_len, tempbuf);
486 } else {
487 /*
488 * buf: [previous hash || passphrase]
489 */
490 memcpy(buf, tempbuf, SHA512_LENGTH);
491 f2fs_sha512(buf, actual_buf_len, tempbuf);
492 }
493 for (y = 0; y < (sizeof(final) / sizeof(*final_u32)); ++y)
494 final_u32[y] = final_u32[y] ^ temp_u32[y];
495 }
496 memcpy(derived_key, final, F2FS_MAX_KEY_SIZE);
497 }
498
disable_echo(struct termios * saved_settings)499 static int disable_echo(struct termios *saved_settings)
500 {
501 struct termios current_settings;
502 int rc = 0;
503
504 rc = tcgetattr(0, ¤t_settings);
505 if (rc)
506 return rc;
507 *saved_settings = current_settings;
508 current_settings.c_lflag &= ~ECHO;
509 rc = tcsetattr(0, TCSANOW, ¤t_settings);
510
511 return rc;
512 }
513
get_passphrase(char * passphrase,int len)514 static void get_passphrase(char *passphrase, int len)
515 {
516 char *p;
517 struct termios current_settings;
518
519 assert(len > 0);
520 disable_echo(¤t_settings);
521 p = fgets(passphrase, len, stdin);
522 tcsetattr(0, TCSANOW, ¤t_settings);
523 printf("\n");
524 if (!p) {
525 printf("Aborting.\n");
526 exit(1);
527 }
528 p = strrchr(passphrase, '\n');
529 if (!p)
530 p = passphrase + len - 1;
531 *p = '\0';
532 }
533
534 struct keyring_map {
535 char name[4];
536 size_t name_len;
537 int code;
538 };
539
540 static const struct keyring_map keyrings[] = {
541 {"@us", 3, KEY_SPEC_USER_SESSION_KEYRING},
542 {"@u", 2, KEY_SPEC_USER_KEYRING},
543 {"@s", 2, KEY_SPEC_SESSION_KEYRING},
544 {"@g", 2, KEY_SPEC_GROUP_KEYRING},
545 {"@p", 2, KEY_SPEC_PROCESS_KEYRING},
546 {"@t", 2, KEY_SPEC_THREAD_KEYRING},
547 };
548
get_keyring_id(const char * keyring)549 static int get_keyring_id(const char *keyring)
550 {
551 unsigned int x;
552 char *end;
553
554 /*
555 * If no keyring is specified, by default use either the user
556 * session key ring or the session keyring. Fetching the
557 * session keyring will return the user session keyring if no
558 * session keyring has been set.
559 *
560 * We need to do this instead of simply adding the key to
561 * KEY_SPEC_SESSION_KEYRING since trying to add a key to a
562 * session keyring that does not yet exist will cause the
563 * kernel to create a session keyring --- which wil then get
564 * garbage collected as soon as f2fscrypt exits.
565 *
566 * The fact that the keyctl system call and the add_key system
567 * call treats KEY_SPEC_SESSION_KEYRING differently when a
568 * session keyring does not exist is very unfortunate and
569 * confusing, but so it goes...
570 */
571 if (keyring == NULL)
572 return keyctl(KEYCTL_GET_KEYRING_ID,
573 KEY_SPEC_SESSION_KEYRING, 0);
574 for (x = 0; x < (sizeof(keyrings) / sizeof(keyrings[0])); ++x) {
575 if (strcmp(keyring, keyrings[x].name) == 0) {
576 return keyrings[x].code;
577 }
578 }
579 x = strtoul(keyring, &end, 10);
580 if (*end == '\0') {
581 if (keyctl(KEYCTL_DESCRIBE, x, NULL, 0) < 0)
582 return 0;
583 return x;
584 }
585 return 0;
586 }
587
generate_key_ref_str(struct salt * salt)588 static void generate_key_ref_str(struct salt *salt)
589 {
590 unsigned char key_ref1[SHA512_LENGTH];
591 unsigned char key_ref2[SHA512_LENGTH];
592 int x;
593
594 f2fs_sha512(salt->key, F2FS_MAX_KEY_SIZE, key_ref1);
595 f2fs_sha512(key_ref1, SHA512_LENGTH, key_ref2);
596 memcpy(salt->key_desc, key_ref2, F2FS_KEY_DESCRIPTOR_SIZE);
597 for (x = 0; x < F2FS_KEY_DESCRIPTOR_SIZE; ++x) {
598 sprintf(&salt->key_ref_str[x * 2], "%02x",
599 salt->key_desc[x]);
600 }
601 salt->key_ref_str[F2FS_KEY_REF_STR_BUF_SIZE - 1] = '\0';
602 }
603
insert_key_into_keyring(const char * keyring,struct salt * salt)604 static void insert_key_into_keyring(const char *keyring, struct salt *salt)
605 {
606 int keyring_id = get_keyring_id(keyring);
607 struct f2fs_encryption_key key;
608 char key_ref_full[F2FS_KEY_DESC_PREFIX_SIZE +
609 F2FS_KEY_REF_STR_BUF_SIZE];
610 int rc;
611
612 if (keyring_id == 0) {
613 printf("Invalid keyring [%s].\n", keyring);
614 exit(1);
615 }
616 sprintf(key_ref_full, "%s%s", F2FS_KEY_DESC_PREFIX,
617 salt->key_ref_str);
618 rc = keyctl(KEYCTL_SEARCH, keyring_id, F2FS_KEY_TYPE_LOGON,
619 key_ref_full, 0);
620 if (rc != -1) {
621 if ((options & OPT_QUIET) == 0)
622 printf("Key with descriptor [%s] already exists\n",
623 salt->key_ref_str);
624 return;
625 } else if ((rc == -1) && (errno != ENOKEY)) {
626 printf("keyctl_search failed: %s\n", strerror(errno));
627 if (errno == -EINVAL)
628 printf("Keyring [%s] is not available.\n", keyring);
629 exit(1);
630 }
631 key.mode = F2FS_ENCRYPTION_MODE_AES_256_XTS;
632 memcpy(key.raw, salt->key, F2FS_MAX_KEY_SIZE);
633 key.size = F2FS_MAX_KEY_SIZE;
634 rc = add_key(F2FS_KEY_TYPE_LOGON, key_ref_full, (void *)&key,
635 sizeof(key), keyring_id);
636 if (rc == -1) {
637 if (errno == EDQUOT) {
638 printf("Error adding key to keyring; quota exceeded\n");
639 } else {
640 printf("Error adding key with key descriptor [%s]: "
641 "%s\n", salt->key_ref_str, strerror(errno));
642 }
643 exit(1);
644 } else {
645 if ((options & OPT_QUIET) == 0)
646 printf("Added key with descriptor [%s]\n",
647 salt->key_ref_str);
648 }
649 }
650
get_default_salts(void)651 static void get_default_salts(void)
652 {
653 FILE *f = setmntent("/etc/mtab", "r");
654 struct mntent *mnt;
655
656 while (f && ((mnt = getmntent(f)) != NULL)) {
657 if (strcmp(mnt->mnt_type, "f2fs") ||
658 access(mnt->mnt_dir, R_OK))
659 continue;
660 parse_salt(mnt->mnt_dir, PARSE_FLAGS_NOTSUPP_OK);
661 }
662 endmntent(f);
663 }
664
665 /* Functions which implement user commands */
666
667 struct cmd_desc {
668 const char *cmd_name;
669 void (*cmd_func)(int, char **, const struct cmd_desc *);
670 const char *cmd_desc;
671 const char *cmd_help;
672 int cmd_flags;
673 };
674
675 #define CMD_HIDDEN 0x0001
676
677 static void do_help(int argc, char **argv, const struct cmd_desc *cmd);
678
679 #define add_key_desc "adds a key to the user's keyring"
680 #define add_key_help \
681 "f2fscrypt add_key -S salt [ -k keyring ] [-v] [-q] [ path ... ]\n\n" \
682 "Prompts the user for a passphrase and inserts it into the specified\n" \
683 "keyring. If no keyring is specified, f2fscrypt will use the session\n" \
684 "keyring if it exists or the user session keyring if it does not.\n\n" \
685 "If one or more directory paths are specified, f2fscrypt will try to\n" \
686 "set the policy of those directories to use the key just entered by\n" \
687 "the user.\n"
688
do_add_key(int argc,char ** argv,const struct cmd_desc * cmd)689 static void do_add_key(int argc, char **argv, const struct cmd_desc *cmd)
690 {
691 struct salt *salt;
692 char *keyring = NULL;
693 int i, opt, pad = 4;
694 unsigned j;
695
696 while ((opt = getopt(argc, argv, "k:S:p:vq")) != -1) {
697 switch (opt) {
698 case 'k':
699 /* Specify a keyring. */
700 keyring = optarg;
701 break;
702 case 'p':
703 pad = atoi(optarg);
704 break;
705 case 'S':
706 /* Salt value for passphrase. */
707 parse_salt(optarg, 0);
708 break;
709 case 'v':
710 options |= OPT_VERBOSE;
711 break;
712 case 'q':
713 options |= OPT_QUIET;
714 break;
715 default:
716 fprintf(stderr, "Unrecognized option: %c\n", opt);
717 case '?':
718 fputs("USAGE:\n ", stderr);
719 fputs(cmd->cmd_help, stderr);
720 exit(1);
721 }
722 }
723 if (num_salt == 0)
724 get_default_salts();
725 if (num_salt == 0) {
726 fprintf(stderr, "No salt values available\n");
727 exit(1);
728 }
729 validate_paths(argc, argv, optind);
730 for (i = optind; i < argc; i++)
731 parse_salt(argv[i], PARSE_FLAGS_FORCE_FN);
732 printf("Enter passphrase (echo disabled): ");
733 get_passphrase(in_passphrase, sizeof(in_passphrase));
734 for (j = 0, salt = salt_list; j < num_salt; j++, salt++) {
735 pbkdf2_sha512(in_passphrase, salt,
736 F2FS_PBKDF2_ITERATIONS, salt->key);
737 generate_key_ref_str(salt);
738 insert_key_into_keyring(keyring, salt);
739 }
740 if (optind != argc)
741 set_policy(NULL, pad, argc, argv, optind);
742 clear_secrets();
743 exit(0);
744 }
745
746 #define set_policy_desc "sets a policy for directories"
747 #define set_policy_help \
748 "f2fscrypt set_policy policy path ... \n\n" \
749 "Sets the policy for the directories specified on the command line.\n" \
750 "All directories must be empty to set the policy; if the directory\n" \
751 "already has a policy established, f2fscrypt will validate that it the\n" \
752 "policy matches what was specified. A policy is an encryption key\n" \
753 "identifier consisting of 16 hexadecimal characters.\n"
754
do_set_policy(int argc,char ** argv,const struct cmd_desc * cmd)755 static void do_set_policy(int argc, char **argv, const struct cmd_desc *cmd)
756 {
757 struct salt saltbuf;
758 int c, pad = 4;
759
760 while ((c = getopt (argc, argv, "p:")) != EOF) {
761 switch (c) {
762 case 'p':
763 pad = atoi(optarg);
764 break;
765 }
766 }
767
768 if (argc < optind + 2) {
769 fprintf(stderr, "Missing required argument(s).\n\n");
770 fputs("USAGE:\n ", stderr);
771 fputs(cmd->cmd_help, stderr);
772 exit(1);
773 }
774
775 if ((strlen(argv[optind]) != (F2FS_KEY_DESCRIPTOR_SIZE * 2)) ||
776 hex2byte(argv[optind], (F2FS_KEY_DESCRIPTOR_SIZE * 2),
777 saltbuf.key_desc, F2FS_KEY_DESCRIPTOR_SIZE)) {
778 printf("Invalid key descriptor [%s]. Valid characters "
779 "are 0-9 and a-f, lower case. "
780 "Length must be %d.\n",
781 argv[optind], (F2FS_KEY_DESCRIPTOR_SIZE * 2));
782 exit(1);
783 }
784 validate_paths(argc, argv, optind+1);
785 strcpy(saltbuf.key_ref_str, argv[optind]);
786 set_policy(&saltbuf, pad, argc, argv, optind+1);
787 exit(0);
788 }
789
790 #define get_policy_desc "get the encryption for directories"
791 #define get_policy_help \
792 "f2fscrypt get_policy path ... \n\n" \
793 "Gets the policy for the directories specified on the command line.\n"
794
do_get_policy(int argc,char ** argv,const struct cmd_desc * cmd)795 static void do_get_policy(int argc, char **argv, const struct cmd_desc *cmd)
796 {
797 struct f2fs_fscrypt_policy policy;
798 struct stat st;
799 int i, j, fd, rc;
800
801 if (argc < 2) {
802 fprintf(stderr, "Missing required argument(s).\n\n");
803 fputs("USAGE:\n ", stderr);
804 fputs(cmd->cmd_help, stderr);
805 exit(1);
806 }
807
808 for (i = 1; i < argc; i++) {
809 if (stat(argv[i], &st) < 0) {
810 perror(argv[i]);
811 continue;
812 }
813 fd = open(argv[i],
814 S_ISDIR(st.st_mode) ? O_DIRECTORY : O_RDONLY);
815 if (fd == -1) {
816 perror(argv[i]);
817 exit(1);
818 }
819 rc = ioctl(fd, F2FS_IOC_GET_ENCRYPTION_POLICY, &policy);
820 close(fd);
821 if (rc) {
822 printf("Error getting policy for %s: %s\n",
823 argv[i], strerror(errno));
824 continue;
825 }
826 printf("%s: ", argv[i]);
827 for (j = 0; j < F2FS_KEY_DESCRIPTOR_SIZE; j++) {
828 printf("%02x", (unsigned char) policy.master_key_descriptor[j]);
829 }
830 fputc('\n', stdout);
831 }
832 exit(0);
833 }
834
835 #define new_session_desc "give the invoking process a new session keyring"
836 #define new_session_help \
837 "f2fscrypt new_session\n\n" \
838 "Give the invoking process (typically a shell) a new session keyring,\n" \
839 "discarding its old session keyring.\n"
840
do_new_session(int argc,char ** UNUSED (argv),const struct cmd_desc * cmd)841 static void do_new_session(int argc, char **UNUSED(argv),
842 const struct cmd_desc *cmd)
843 {
844 long keyid, ret;
845
846 if (argc > 1) {
847 fputs("Excess arguments\n\n", stderr);
848 fputs(cmd->cmd_help, stderr);
849 exit(1);
850 }
851 keyid = keyctl(KEYCTL_JOIN_SESSION_KEYRING, NULL);
852 if (keyid < 0) {
853 perror("KEYCTL_JOIN_SESSION_KEYRING");
854 exit(1);
855 }
856 ret = keyctl(KEYCTL_SESSION_TO_PARENT, NULL);
857 if (ret < 0) {
858 perror("KEYCTL_SESSION_TO_PARENT");
859 exit(1);
860 }
861 printf("Switched invoking process to new session keyring %ld\n", keyid);
862 exit(0);
863 }
864
865 #define CMD(name) { #name, do_##name, name##_desc, name##_help, 0 }
866 #define _CMD(name) { #name, do_##name, NULL, NULL, CMD_HIDDEN }
867
868 const struct cmd_desc cmd_list[] = {
869 _CMD(help),
870 CMD(add_key),
871 CMD(get_policy),
872 CMD(new_session),
873 CMD(set_policy),
874 { NULL, NULL, NULL, NULL, 0 }
875 };
876
do_help(int argc,char ** argv,const struct cmd_desc * UNUSED (cmd))877 static void do_help(int argc, char **argv, const struct cmd_desc *UNUSED(cmd))
878 {
879 const struct cmd_desc *p;
880
881 if (argc > 1) {
882 for (p = cmd_list; p->cmd_name; p++) {
883 if (p->cmd_flags & CMD_HIDDEN)
884 continue;
885 if (strcmp(p->cmd_name, argv[1]) == 0) {
886 putc('\n', stdout);
887 fputs("USAGE:\n ", stdout);
888 fputs(p->cmd_help, stdout);
889 exit(0);
890 }
891 }
892 printf("Unknown command: %s\n\n", argv[1]);
893 }
894
895 fputs("Available commands:\n", stdout);
896 for (p = cmd_list; p->cmd_name; p++) {
897 if (p->cmd_flags & CMD_HIDDEN)
898 continue;
899 printf(" %-20s %s\n", p->cmd_name, p->cmd_desc);
900 }
901 printf("\nTo get more information on a command, "
902 "type 'f2fscrypt help cmd'\n");
903 exit(0);
904 }
905
main(int argc,char * argv[])906 int main(int argc, char *argv[])
907 {
908 const struct cmd_desc *cmd;
909
910 if (argc < 2)
911 do_help(argc, argv, cmd_list);
912
913 sigcatcher_setup();
914 for (cmd = cmd_list; cmd->cmd_name; cmd++) {
915 if (strcmp(cmd->cmd_name, argv[1]) == 0) {
916 cmd->cmd_func(argc-1, argv+1, cmd);
917 exit(0);
918 }
919 }
920 printf("Unknown command: %s\n\n", argv[1]);
921 do_help(1, argv, cmd_list);
922 return 0;
923 }
924