3  * Encryption policy functions for per-file encryption support.
10  * Modified by Eric Biggers, 2019 for v2 policy support.
22  * @policy1: the first policy
23  * @policy2: the second policy
36 int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy,  in fscrypt_policy_to_key_spec()  argument
39 	switch (policy->version) {  in fscrypt_policy_to_key_spec()
42 		memcpy(key_spec->u.descriptor, policy->v1.master_key_descriptor,  in fscrypt_policy_to_key_spec()
47 		memcpy(key_spec->u.identifier, policy->v2.master_key_identifier,  in fscrypt_policy_to_key_spec()
120 static bool supported_iv_ino_lblk_policy(const struct fscrypt_policy_v2 *policy,  in supported_iv_ino_lblk_policy()  argument
123 	const char *type = (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64)  in supported_iv_ino_lblk_policy()
134 	if (policy->contents_encryption_mode != FSCRYPT_MODE_AES_256_XTS) {  in supported_iv_ino_lblk_policy()
136 			     "Can't use %s policy with contents mode other than AES-256-XTS",  in supported_iv_ino_lblk_policy()
148 			     "Can't use %s policy on filesystem '%s' because it doesn't have stable inode numbers",  in supported_iv_ino_lblk_policy()
162 			     "Can't use %s policy on filesystem '%s' because its inode numbers are too long",  in supported_iv_ino_lblk_policy()
172 			fscrypt_policy_v2_du_bits(policy, inode)) > 32) {  in supported_iv_ino_lblk_policy()
174 			     "Can't use %s policy on filesystem '%s' because its maximum file size is too large",  in supported_iv_ino_lblk_policy()
181 static bool fscrypt_supported_v1_policy(const struct fscrypt_policy_v1 *policy,  in fscrypt_supported_v1_policy()  argument
184 	if (!fscrypt_valid_enc_modes_v1(policy->contents_encryption_mode,  in fscrypt_supported_v1_policy()
185 				     policy->filenames_encryption_mode)) {  in fscrypt_supported_v1_policy()
188 			     policy->contents_encryption_mode,  in fscrypt_supported_v1_policy()
189 			     policy->filenames_encryption_mode);  in fscrypt_supported_v1_policy()
193 	if (policy->flags & ~(FSCRYPT_POLICY_FLAGS_PAD_MASK |  in fscrypt_supported_v1_policy()
196 			     policy->flags);  in fscrypt_supported_v1_policy()
200 	if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&  in fscrypt_supported_v1_policy()
201 	    !supported_direct_key_modes(inode, policy->contents_encryption_mode,  in fscrypt_supported_v1_policy()
202 					policy->filenames_encryption_mode))  in fscrypt_supported_v1_policy()
215 static bool fscrypt_supported_v2_policy(const struct fscrypt_policy_v2 *policy,  in fscrypt_supported_v2_policy()  argument
220 	if (!fscrypt_valid_enc_modes_v2(policy->contents_encryption_mode,  in fscrypt_supported_v2_policy()
221 				     policy->filenames_encryption_mode)) {  in fscrypt_supported_v2_policy()
224 			     policy->contents_encryption_mode,  in fscrypt_supported_v2_policy()
225 			     policy->filenames_encryption_mode);  in fscrypt_supported_v2_policy()
229 	if (policy->flags & ~(FSCRYPT_POLICY_FLAGS_PAD_MASK |  in fscrypt_supported_v2_policy()
234 			     policy->flags);  in fscrypt_supported_v2_policy()
238 	count += !!(policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY);  in fscrypt_supported_v2_policy()
239 	count += !!(policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64);  in fscrypt_supported_v2_policy()
240 	count += !!(policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32);  in fscrypt_supported_v2_policy()
243 			     policy->flags);  in fscrypt_supported_v2_policy()
247 	if (policy->log2_data_unit_size) {  in fscrypt_supported_v2_policy()
253 		if (policy->log2_data_unit_size > inode->i_blkbits ||  in fscrypt_supported_v2_policy()
254 		    policy->log2_data_unit_size < SECTOR_SHIFT /* 9 */) {  in fscrypt_supported_v2_policy()
256 				     "Unsupported log2_data_unit_size in encryption policy: %d",  in fscrypt_supported_v2_policy()
257 				     policy->log2_data_unit_size);  in fscrypt_supported_v2_policy()
260 		if (policy->log2_data_unit_size != inode->i_blkbits &&  in fscrypt_supported_v2_policy()
261 		    (policy->flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {  in fscrypt_supported_v2_policy()
272 	if ((policy->flags & FSCRYPT_POLICY_FLAG_DIRECT_KEY) &&  in fscrypt_supported_v2_policy()
273 	    !supported_direct_key_modes(inode, policy->contents_encryption_mode,  in fscrypt_supported_v2_policy()
274 					policy->filenames_encryption_mode))  in fscrypt_supported_v2_policy()
277 	if ((policy->flags & (FSCRYPT_POLICY_FLAG_IV_INO_LBLK_64 |  in fscrypt_supported_v2_policy()
279 	    !supported_iv_ino_lblk_policy(policy, inode))  in fscrypt_supported_v2_policy()
282 	if (memchr_inv(policy->__reserved, 0, sizeof(policy->__reserved))) {  in fscrypt_supported_v2_policy()
283 		fscrypt_warn(inode, "Reserved bits set in encryption policy");  in fscrypt_supported_v2_policy()
291  * fscrypt_supported_policy() - check whether an encryption policy is supported
292  * @policy_u: the encryption policy
293  * @inode: the inode on which the policy will be used
295  * Given an encryption policy, check whether all its encryption modes and other
317  * @policy_u: input policy
321  * encryption policy.  @nonce must be a new random nonce.
333 		const struct fscrypt_policy_v1 *policy = &policy_u->v1;  in fscrypt_new_context()  local
338 			policy->contents_encryption_mode;  in fscrypt_new_context()
340 			policy->filenames_encryption_mode;  in fscrypt_new_context()
341 		ctx->flags = policy->flags;  in fscrypt_new_context()
343 		       policy->master_key_descriptor,  in fscrypt_new_context()
349 		const struct fscrypt_policy_v2 *policy = &policy_u->v2;  in fscrypt_new_context()  local
354 			policy->contents_encryption_mode;  in fscrypt_new_context()
356 			policy->filenames_encryption_mode;  in fscrypt_new_context()
357 		ctx->flags = policy->flags;  in fscrypt_new_context()
358 		ctx->log2_data_unit_size = policy->log2_data_unit_size;  in fscrypt_new_context()
360 		       policy->master_key_identifier,  in fscrypt_new_context()
372  * @policy_u: output policy
381  * This does *not* validate the settings within the policy itself, e.g. the
396 		struct fscrypt_policy_v1 *policy = &policy_u->v1;  in fscrypt_policy_from_context()  local
398 		policy->version = FSCRYPT_POLICY_V1;  in fscrypt_policy_from_context()
399 		policy->contents_encryption_mode =  in fscrypt_policy_from_context()
401 		policy->filenames_encryption_mode =  in fscrypt_policy_from_context()
403 		policy->flags = ctx->flags;  in fscrypt_policy_from_context()
404 		memcpy(policy->master_key_descriptor,  in fscrypt_policy_from_context()
406 		       sizeof(policy->master_key_descriptor));  in fscrypt_policy_from_context()
411 		struct fscrypt_policy_v2 *policy = &policy_u->v2;  in fscrypt_policy_from_context()  local
413 		policy->version = FSCRYPT_POLICY_V2;  in fscrypt_policy_from_context()
414 		policy->contents_encryption_mode =  in fscrypt_policy_from_context()
416 		policy->filenames_encryption_mode =  in fscrypt_policy_from_context()
418 		policy->flags = ctx->flags;  in fscrypt_policy_from_context()
419 		policy->log2_data_unit_size = ctx->log2_data_unit_size;  in fscrypt_policy_from_context()
420 		memcpy(policy->__reserved, ctx->__reserved,  in fscrypt_policy_from_context()
421 		       sizeof(policy->__reserved));  in fscrypt_policy_from_context()
422 		memcpy(policy->master_key_identifier,  in fscrypt_policy_from_context()
424 		       sizeof(policy->master_key_identifier));  in fscrypt_policy_from_context()
432 /* Retrieve an inode's encryption policy */
433 static int fscrypt_get_policy(struct inode *inode, union fscrypt_policy *policy)  in fscrypt_get_policy()  argument
441 		/* key available, use the cached policy */  in fscrypt_get_policy()
442 		*policy = ci->ci_policy;  in fscrypt_get_policy()
453 	return fscrypt_policy_from_context(policy, &ctx, ret);  in fscrypt_get_policy()
457 				 const union fscrypt_policy *policy)  in set_encryption_policy()  argument
464 	if (!fscrypt_supported_policy(policy, inode))  in set_encryption_policy()
467 	switch (policy->version) {  in set_encryption_policy()
470 		 * The original encryption policy version provided no way of  in set_encryption_policy()
474 		 * encryption policy version fixes this and also implies use of  in set_encryption_policy()
478 		 * policy version for all new encrypted directories.  in set_encryption_policy()
480 …pr_warn_once("%s (pid %d) is setting deprecated v1 encryption policy; recommend upgrading to v2.\n…  in set_encryption_policy()
485 					       policy->v2.master_key_identifier);  in set_encryption_policy()
488 		if (policy->v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)  in set_encryption_policy()
489 …pr_warn_once("%s (pid %d) is setting an IV_INO_LBLK_32 encryption policy.  This should only be use…  in set_encryption_policy()
498 	ctxsize = fscrypt_new_context(&ctx, policy, nonce);  in set_encryption_policy()
505 	union fscrypt_policy policy;  in fscrypt_ioctl_set_policy()  local
512 	if (get_user(policy.version, (const u8 __user *)arg))  in fscrypt_ioctl_set_policy()
515 	size = fscrypt_policy_size(&policy);  in fscrypt_ioctl_set_policy()
530 	version = policy.version;  in fscrypt_ioctl_set_policy()
531 	if (copy_from_user(&policy, arg, size))  in fscrypt_ioctl_set_policy()
533 	policy.version = version;  in fscrypt_ioctl_set_policy()
553 			ret = set_encryption_policy(inode, &policy);  in fscrypt_ioctl_set_policy()
555 		   (ret == 0 && !fscrypt_policies_equal(&policy,  in fscrypt_ioctl_set_policy()
557 		/* The file already uses a different encryption policy. */  in fscrypt_ioctl_set_policy()
568 /* Original ioctl version; can only get the original policy version */
571 	union fscrypt_policy policy;  in fscrypt_ioctl_get_policy()  local
574 	err = fscrypt_get_policy(file_inode(filp), &policy);  in fscrypt_ioctl_get_policy()
578 	if (policy.version != FSCRYPT_POLICY_V1)  in fscrypt_ioctl_get_policy()
581 	if (copy_to_user(arg, &policy, sizeof(policy.v1)))  in fscrypt_ioctl_get_policy()
591 	union fscrypt_policy *policy = (union fscrypt_policy *)&arg.policy;  in fscrypt_ioctl_get_policy_ex()  local
595 	/* arg is policy_size, then policy */  in fscrypt_ioctl_get_policy_ex()
598 		     offsetof(typeof(arg), policy));  in fscrypt_ioctl_get_policy_ex()
599 	BUILD_BUG_ON(sizeof(arg.policy) != sizeof(*policy));  in fscrypt_ioctl_get_policy_ex()
601 	err = fscrypt_get_policy(file_inode(filp), policy);  in fscrypt_ioctl_get_policy_ex()
604 	policy_size = fscrypt_policy_size(policy);  in fscrypt_ioctl_get_policy_ex()
639  * fscrypt_has_permitted_context() - is a file's encryption policy permitted
651  * same encryption policy.  The pre-access check is needed to detect potentially
677 	 * encryption policy.  Compare the cached policies if the keys are  in fscrypt_has_permitted_context()
702 	 * encryption policy, so that files with an unrecognized encryption  in fscrypt_has_permitted_context()
703 	 * policy can be deleted.  in fscrypt_has_permitted_context()
716  * Return the encryption policy that new files in the directory will inherit, or
737  * @inode: inode from which to fetch policy and nonce
795  * @dummy_policy: (input/output) the place to write the dummy policy that will
796  *	result from parsing the option.  Zero-initialize this.  If a policy is
807 	union fscrypt_policy *policy;  in fscrypt_parse_test_dummy_encryption()  local
813 	policy = kzalloc(sizeof(*policy), GFP_KERNEL);  in fscrypt_parse_test_dummy_encryption()
814 	if (!policy)  in fscrypt_parse_test_dummy_encryption()
818 		policy->version = FSCRYPT_POLICY_V1;  in fscrypt_parse_test_dummy_encryption()
819 		policy->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;  in fscrypt_parse_test_dummy_encryption()
820 		policy->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;  in fscrypt_parse_test_dummy_encryption()
821 		memset(policy->v1.master_key_descriptor, 0x42,  in fscrypt_parse_test_dummy_encryption()
824 		policy->version = FSCRYPT_POLICY_V2;  in fscrypt_parse_test_dummy_encryption()
825 		policy->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;  in fscrypt_parse_test_dummy_encryption()
826 		policy->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;  in fscrypt_parse_test_dummy_encryption()
828 				policy->v2.master_key_identifier);  in fscrypt_parse_test_dummy_encryption()
836 	if (dummy_policy->policy) {  in fscrypt_parse_test_dummy_encryption()
837 		if (fscrypt_policies_equal(policy, dummy_policy->policy))  in fscrypt_parse_test_dummy_encryption()
843 	dummy_policy->policy = policy;  in fscrypt_parse_test_dummy_encryption()
844 	policy = NULL;  in fscrypt_parse_test_dummy_encryption()
847 	kfree(policy);  in fscrypt_parse_test_dummy_encryption()
854  * @p1: the first test dummy policy (may be unset)
855  * @p2: the second test dummy policy (may be unset)
862 	if (!p1->policy && !p2->policy)  in fscrypt_dummy_policies_equal()
864 	if (!p1->policy || !p2->policy)  in fscrypt_dummy_policies_equal()
866 	return fscrypt_policies_equal(p1->policy, p2->policy);  in fscrypt_dummy_policies_equal()
882 	const union fscrypt_policy *policy = fscrypt_get_dummy_policy(sb);  in fscrypt_show_test_dummy_encryption()  local
885 	if (!policy)  in fscrypt_show_test_dummy_encryption()
888 	vers = policy->version;  in fscrypt_show_test_dummy_encryption()