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Diffstat (limited to 'fs/crypto/policy.c')
-rw-r--r--fs/crypto/policy.c113
1 files changed, 69 insertions, 44 deletions
diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index 4ff893f7b030..97cf07543651 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -32,6 +32,14 @@ bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
return !memcmp(policy1, policy2, fscrypt_policy_size(policy1));
}
+static const union fscrypt_policy *
+fscrypt_get_dummy_policy(struct super_block *sb)
+{
+ if (!sb->s_cop->get_dummy_policy)
+ return NULL;
+ return sb->s_cop->get_dummy_policy(sb);
+}
+
static bool fscrypt_valid_enc_modes(u32 contents_mode, u32 filenames_mode)
{
if (contents_mode == FSCRYPT_MODE_AES_256_XTS &&
@@ -628,6 +636,25 @@ int fscrypt_has_permitted_context(struct inode *parent, struct inode *child)
}
EXPORT_SYMBOL(fscrypt_has_permitted_context);
+/*
+ * Return the encryption policy that new files in the directory will inherit, or
+ * NULL if none, or an ERR_PTR() on error. If the directory is encrypted, also
+ * ensure that its key is set up, so that the new filename can be encrypted.
+ */
+const union fscrypt_policy *fscrypt_policy_to_inherit(struct inode *dir)
+{
+ int err;
+
+ if (IS_ENCRYPTED(dir)) {
+ err = fscrypt_require_key(dir);
+ if (err)
+ return ERR_PTR(err);
+ return &dir->i_crypt_info->ci_policy;
+ }
+
+ return fscrypt_get_dummy_policy(dir->i_sb);
+}
+
/**
* fscrypt_set_context() - Set the fscrypt context of a new inode
* @inode: a new inode
@@ -672,31 +699,28 @@ EXPORT_SYMBOL_GPL(fscrypt_set_context);
* @sb: the filesystem on which test_dummy_encryption is being specified
* @arg: the argument to the test_dummy_encryption option.
* If no argument was specified, then @arg->from == NULL.
- * @dummy_ctx: the filesystem's current dummy context (input/output, see below)
+ * @dummy_policy: the filesystem's current dummy policy (input/output, see
+ * below)
*
* Handle the test_dummy_encryption mount option by creating a dummy encryption
- * context, saving it in @dummy_ctx, and adding the corresponding dummy
- * encryption key to the filesystem. If the @dummy_ctx is already set, then
+ * policy, saving it in @dummy_policy, and adding the corresponding dummy
+ * encryption key to the filesystem. If the @dummy_policy is already set, then
* instead validate that it matches @arg. Don't support changing it via
* remount, as that is difficult to do safely.
*
- * The reason we use an fscrypt_context rather than an fscrypt_policy is because
- * we mustn't generate a new nonce each time we access a dummy-encrypted
- * directory, as that would change the way filenames are encrypted.
- *
- * Return: 0 on success (dummy context set, or the same context is already set);
- * -EEXIST if a different dummy context is already set;
+ * Return: 0 on success (dummy policy set, or the same policy is already set);
+ * -EEXIST if a different dummy policy is already set;
* or another -errno value.
*/
int fscrypt_set_test_dummy_encryption(struct super_block *sb,
const substring_t *arg,
- struct fscrypt_dummy_context *dummy_ctx)
+ struct fscrypt_dummy_policy *dummy_policy)
{
const char *argstr = "v2";
const char *argstr_to_free = NULL;
struct fscrypt_key_specifier key_spec = { 0 };
int version;
- union fscrypt_context *ctx = NULL;
+ union fscrypt_policy *policy = NULL;
int err;
if (arg->from) {
@@ -706,12 +730,12 @@ int fscrypt_set_test_dummy_encryption(struct super_block *sb,
}
if (!strcmp(argstr, "v1")) {
- version = FSCRYPT_CONTEXT_V1;
+ version = FSCRYPT_POLICY_V1;
key_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
memset(key_spec.u.descriptor, 0x42,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
} else if (!strcmp(argstr, "v2")) {
- version = FSCRYPT_CONTEXT_V2;
+ version = FSCRYPT_POLICY_V2;
key_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
/* key_spec.u.identifier gets filled in when adding the key */
} else {
@@ -719,21 +743,8 @@ int fscrypt_set_test_dummy_encryption(struct super_block *sb,
goto out;
}
- if (dummy_ctx->ctx) {
- /*
- * Note: if we ever make test_dummy_encryption support
- * specifying other encryption settings, such as the encryption
- * modes, we'll need to compare those settings here.
- */
- if (dummy_ctx->ctx->version == version)
- err = 0;
- else
- err = -EEXIST;
- goto out;
- }
-
- ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
- if (!ctx) {
+ policy = kzalloc(sizeof(*policy), GFP_KERNEL);
+ if (!policy) {
err = -ENOMEM;
goto out;
}
@@ -742,18 +753,18 @@ int fscrypt_set_test_dummy_encryption(struct super_block *sb,
if (err)
goto out;
- ctx->version = version;
- switch (ctx->version) {
- case FSCRYPT_CONTEXT_V1:
- ctx->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
- ctx->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
- memcpy(ctx->v1.master_key_descriptor, key_spec.u.descriptor,
+ policy->version = version;
+ switch (policy->version) {
+ case FSCRYPT_POLICY_V1:
+ policy->v1.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
+ policy->v1.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
+ memcpy(policy->v1.master_key_descriptor, key_spec.u.descriptor,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
break;
- case FSCRYPT_CONTEXT_V2:
- ctx->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
- ctx->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
- memcpy(ctx->v2.master_key_identifier, key_spec.u.identifier,
+ case FSCRYPT_POLICY_V2:
+ policy->v2.contents_encryption_mode = FSCRYPT_MODE_AES_256_XTS;
+ policy->v2.filenames_encryption_mode = FSCRYPT_MODE_AES_256_CTS;
+ memcpy(policy->v2.master_key_identifier, key_spec.u.identifier,
FSCRYPT_KEY_IDENTIFIER_SIZE);
break;
default:
@@ -761,11 +772,19 @@ int fscrypt_set_test_dummy_encryption(struct super_block *sb,
err = -EINVAL;
goto out;
}
- dummy_ctx->ctx = ctx;
- ctx = NULL;
+
+ if (dummy_policy->policy) {
+ if (fscrypt_policies_equal(policy, dummy_policy->policy))
+ err = 0;
+ else
+ err = -EEXIST;
+ goto out;
+ }
+ dummy_policy->policy = policy;
+ policy = NULL;
err = 0;
out:
- kfree(ctx);
+ kfree(policy);
kfree(argstr_to_free);
return err;
}
@@ -783,10 +802,16 @@ EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption);
void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
struct super_block *sb)
{
- const union fscrypt_context *ctx = fscrypt_get_dummy_context(sb);
+ const union fscrypt_policy *policy = fscrypt_get_dummy_policy(sb);
+ int vers;
- if (!ctx)
+ if (!policy)
return;
- seq_printf(seq, "%ctest_dummy_encryption=v%d", sep, ctx->version);
+
+ vers = policy->version;
+ if (vers == FSCRYPT_POLICY_V1) /* Handle numbering quirk */
+ vers = 1;
+
+ seq_printf(seq, "%ctest_dummy_encryption=v%d", sep, vers);
}
EXPORT_SYMBOL_GPL(fscrypt_show_test_dummy_encryption);
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-28 15:27:56 +0000