fscrypt: factor out fscrypt_policy_to_key_spec()

Factor out a function that builds the fscrypt_key_specifier for an
fscrypt_policy.  Before this was only needed when finding the key for a
file, but now it will also be needed for test_dummy_encryption support.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20220501050857.538984-4-ebiggers@kernel.org
This commit is contained in:
Eric Biggers 2022-04-30 22:08:53 -07:00
parent a7a5bc5fe8
commit bfb9700bdf
3 changed files with 25 additions and 17 deletions

View File

@ -623,6 +623,8 @@ int fscrypt_setup_v1_file_key_via_subscribed_keyrings(struct fscrypt_info *ci);
bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
const union fscrypt_policy *policy2);
int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy,
struct fscrypt_key_specifier *key_spec);
bool fscrypt_supported_policy(const union fscrypt_policy *policy_u,
const struct inode *inode);
int fscrypt_policy_from_context(union fscrypt_policy *policy_u,

View File

@ -425,23 +425,9 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
if (err)
return err;
switch (ci->ci_policy.version) {
case FSCRYPT_POLICY_V1:
mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
memcpy(mk_spec.u.descriptor,
ci->ci_policy.v1.master_key_descriptor,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
break;
case FSCRYPT_POLICY_V2:
mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
memcpy(mk_spec.u.identifier,
ci->ci_policy.v2.master_key_identifier,
FSCRYPT_KEY_IDENTIFIER_SIZE);
break;
default:
WARN_ON(1);
return -EINVAL;
}
err = fscrypt_policy_to_key_spec(&ci->ci_policy, &mk_spec);
if (err)
return err;
key = fscrypt_find_master_key(ci->ci_inode->i_sb, &mk_spec);
if (IS_ERR(key)) {

View File

@ -32,6 +32,26 @@ bool fscrypt_policies_equal(const union fscrypt_policy *policy1,
return !memcmp(policy1, policy2, fscrypt_policy_size(policy1));
}
int fscrypt_policy_to_key_spec(const union fscrypt_policy *policy,
struct fscrypt_key_specifier *key_spec)
{
switch (policy->version) {
case FSCRYPT_POLICY_V1:
key_spec->type = FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR;
memcpy(key_spec->u.descriptor, policy->v1.master_key_descriptor,
FSCRYPT_KEY_DESCRIPTOR_SIZE);
return 0;
case FSCRYPT_POLICY_V2:
key_spec->type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
memcpy(key_spec->u.identifier, policy->v2.master_key_identifier,
FSCRYPT_KEY_IDENTIFIER_SIZE);
return 0;
default:
WARN_ON(1);
return -EINVAL;
}
}
static const union fscrypt_policy *
fscrypt_get_dummy_policy(struct super_block *sb)
{