Commit bfb9700b authored by Eric Biggers's avatar Eric Biggers
Browse files

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: default avatarEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20220501050857.538984-4-ebiggers@kernel.org
parent a7a5bc5f

fs/crypto/fscrypt_private.h

+2 −0
Original line number Diff line number Diff line
@@ -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,

fs/crypto/keysetup.c

+3 −17
Original line number Diff line number Diff line
@@ -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)) {

fs/crypto/policy.c

+20 −0
Original line number Diff line number Diff line
@@ -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)

{