Commit Graph

32 Commits

Author SHA1 Message Date
Daniel W. S. Almeida 402613f3ef Documentation: security: core.rst: fix warnings
Fix warnings due to missing markup, no change in content otherwise.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Link: https://lore.kernel.org/r/20191122041806.68650-1-dwlsalmeida@gmail.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-11-22 10:01:47 -07:00
Linus Torvalds 028db3e290 Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs"
This reverts merge 0f75ef6a9c (and thus
effectively commits

   7a1ade8475 ("keys: Provide KEYCTL_GRANT_PERMISSION")
   2e12256b9a ("keys: Replace uid/gid/perm permissions checking with an ACL")

that the merge brought in).

It turns out that it breaks booting with an encrypted volume, and Eric
biggers reports that it also breaks the fscrypt tests [1] and loading of
in-kernel X.509 certificates [2].

The root cause of all the breakage is likely the same, but David Howells
is off email so rather than try to work it out it's getting reverted in
order to not impact the rest of the merge window.

 [1] https://lore.kernel.org/lkml/20190710011559.GA7973@sol.localdomain/
 [2] https://lore.kernel.org/lkml/20190710013225.GB7973@sol.localdomain/

Link: https://lore.kernel.org/lkml/CAHk-=wjxoeMJfeBahnWH=9zShKp2bsVy527vo3_y8HfOdhwAAw@mail.gmail.com/
Reported-by: Eric Biggers <ebiggers@kernel.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-10 18:43:43 -07:00
Linus Torvalds e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
David Howells 2e12256b9a keys: Replace uid/gid/perm permissions checking with an ACL
Replace the uid/gid/perm permissions checking on a key with an ACL to allow
the SETATTR and SEARCH permissions to be split.  This will also allow a
greater range of subjects to represented.

============
WHY DO THIS?
============

The problem is that SETATTR and SEARCH cover a slew of actions, not all of
which should be grouped together.

For SETATTR, this includes actions that are about controlling access to a
key:

 (1) Changing a key's ownership.

 (2) Changing a key's security information.

 (3) Setting a keyring's restriction.

And actions that are about managing a key's lifetime:

 (4) Setting an expiry time.

 (5) Revoking a key.

and (proposed) managing a key as part of a cache:

 (6) Invalidating a key.

Managing a key's lifetime doesn't really have anything to do with
controlling access to that key.

Expiry time is awkward since it's more about the lifetime of the content
and so, in some ways goes better with WRITE permission.  It can, however,
be set unconditionally by a process with an appropriate authorisation token
for instantiating a key, and can also be set by the key type driver when a
key is instantiated, so lumping it with the access-controlling actions is
probably okay.

As for SEARCH permission, that currently covers:

 (1) Finding keys in a keyring tree during a search.

 (2) Permitting keyrings to be joined.

 (3) Invalidation.

But these don't really belong together either, since these actions really
need to be controlled separately.

Finally, there are number of special cases to do with granting the
administrator special rights to invalidate or clear keys that I would like
to handle with the ACL rather than key flags and special checks.


===============
WHAT IS CHANGED
===============

The SETATTR permission is split to create two new permissions:

 (1) SET_SECURITY - which allows the key's owner, group and ACL to be
     changed and a restriction to be placed on a keyring.

 (2) REVOKE - which allows a key to be revoked.

The SEARCH permission is split to create:

 (1) SEARCH - which allows a keyring to be search and a key to be found.

 (2) JOIN - which allows a keyring to be joined as a session keyring.

 (3) INVAL - which allows a key to be invalidated.

The WRITE permission is also split to create:

 (1) WRITE - which allows a key's content to be altered and links to be
     added, removed and replaced in a keyring.

 (2) CLEAR - which allows a keyring to be cleared completely.  This is
     split out to make it possible to give just this to an administrator.

 (3) REVOKE - see above.


Keys acquire ACLs which consist of a series of ACEs, and all that apply are
unioned together.  An ACE specifies a subject, such as:

 (*) Possessor - permitted to anyone who 'possesses' a key
 (*) Owner - permitted to the key owner
 (*) Group - permitted to the key group
 (*) Everyone - permitted to everyone

Note that 'Other' has been replaced with 'Everyone' on the assumption that
you wouldn't grant a permit to 'Other' that you wouldn't also grant to
everyone else.

Further subjects may be made available by later patches.

The ACE also specifies a permissions mask.  The set of permissions is now:

	VIEW		Can view the key metadata
	READ		Can read the key content
	WRITE		Can update/modify the key content
	SEARCH		Can find the key by searching/requesting
	LINK		Can make a link to the key
	SET_SECURITY	Can change owner, ACL, expiry
	INVAL		Can invalidate
	REVOKE		Can revoke
	JOIN		Can join this keyring
	CLEAR		Can clear this keyring


The KEYCTL_SETPERM function is then deprecated.

The KEYCTL_SET_TIMEOUT function then is permitted if SET_SECURITY is set,
or if the caller has a valid instantiation auth token.

The KEYCTL_INVALIDATE function then requires INVAL.

The KEYCTL_REVOKE function then requires REVOKE.

The KEYCTL_JOIN_SESSION_KEYRING function then requires JOIN to join an
existing keyring.

The JOIN permission is enabled by default for session keyrings and manually
created keyrings only.


======================
BACKWARD COMPATIBILITY
======================

To maintain backward compatibility, KEYCTL_SETPERM will translate the
permissions mask it is given into a new ACL for a key - unless
KEYCTL_SET_ACL has been called on that key, in which case an error will be
returned.

It will convert possessor, owner, group and other permissions into separate
ACEs, if each portion of the mask is non-zero.

SETATTR permission turns on all of INVAL, REVOKE and SET_SECURITY.  WRITE
permission turns on WRITE, REVOKE and, if a keyring, CLEAR.  JOIN is turned
on if a keyring is being altered.

The KEYCTL_DESCRIBE function translates the ACL back into a permissions
mask to return depending on possessor, owner, group and everyone ACEs.

It will make the following mappings:

 (1) INVAL, JOIN -> SEARCH

 (2) SET_SECURITY -> SETATTR

 (3) REVOKE -> WRITE if SETATTR isn't already set

 (4) CLEAR -> WRITE

Note that the value subsequently returned by KEYCTL_DESCRIBE may not match
the value set with KEYCTL_SETATTR.


=======
TESTING
=======

This passes the keyutils testsuite for all but a couple of tests:

 (1) tests/keyctl/dh_compute/badargs: The first wrong-key-type test now
     returns EOPNOTSUPP rather than ENOKEY as READ permission isn't removed
     if the type doesn't have ->read().  You still can't actually read the
     key.

 (2) tests/keyctl/permitting/valid: The view-other-permissions test doesn't
     work as Other has been replaced with Everyone in the ACL.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-27 23:03:07 +01:00
David Howells a58946c158 keys: Pass the network namespace into request_key mechanism
Create a request_key_net() function and use it to pass the network
namespace domain tag into DNS revolver keys and rxrpc/AFS keys so that keys
for different domains can coexist in the same keyring.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: netdev@vger.kernel.org
cc: linux-nfs@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: linux-afs@lists.infradead.org
2019-06-27 23:02:12 +01:00
David Howells dcf49dbc80 keys: Add a 'recurse' flag for keyring searches
Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-26 21:02:32 +01:00
David Howells 3b8c4a08a4 keys: Kill off request_key_async{,_with_auxdata}
Kill off request_key_async{,_with_auxdata}() as they're not currently used.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-26 20:58:13 +01:00
David Howells 7743c48e54 keys: Cache result of request_key*() temporarily in task_struct
If a filesystem uses keys to hold authentication tokens, then it needs a
token for each VFS operation that might perform an authentication check -
either by passing it to the server, or using to perform a check based on
authentication data cached locally.

For open files this isn't a problem, since the key should be cached in the
file struct since it represents the subject performing operations on that
file descriptor.

During pathwalk, however, there isn't anywhere to cache the key, except
perhaps in the nameidata struct - but that isn't exposed to the
filesystems.  Further, a pathwalk can incur a lot of operations, calling
one or more of the following, for instance:

	->lookup()
	->permission()
	->d_revalidate()
	->d_automount()
	->get_acl()
	->getxattr()

on each dentry/inode it encounters - and each one may need to call
request_key().  And then, at the end of pathwalk, it will call the actual
operation:

	->mkdir()
	->mknod()
	->getattr()
	->open()
	...

which may need to go and get the token again.

However, it is very likely that all of the operations on a single
dentry/inode - and quite possibly a sequence of them - will all want to use
the same authentication token, which suggests that caching it would be a
good idea.

To this end:

 (1) Make it so that a positive result of request_key() and co. that didn't
     require upcalling to userspace is cached temporarily in task_struct.

 (2) The cache is 1 deep, so a new result displaces the old one.

 (3) The key is released by exit and by notify-resume.

 (4) The cache is cleared in a newly forked process.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-19 16:10:15 +01:00
David Howells 896f1950e5 keys: Provide request_key_rcu()
Provide a request_key_rcu() function that can be used to request a key
under RCU conditions.  It can only search and check permissions; it cannot
allocate a new key, upcall or wait for an upcall to complete.  It may
return a partially constructed key.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-19 16:10:15 +01:00
David Howells e59428f721 keys: Move the RCU locks outwards from the keyring search functions
Move the RCU locks outwards from the keyring search functions so that it
will become possible to provide an RCU-capable partial request_key()
function in a later commit.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-19 16:10:15 +01:00
David Howells 504b69eb3c keys: Fix request_key() lack of Link perm check on found key
The request_key() syscall allows a process to gain access to the 'possessor'
permits of any key that grants it Search permission by virtue of request_key()
not checking whether a key it finds grants Link permission to the caller.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-19 16:10:15 +01:00
Mauro Carvalho Chehab 43415f1327 docs: security: core.rst: Fix several warnings
Multi-line literal markups only work when they're idented at the
same level, with is not the case here:

   Documentation/security/keys/core.rst:1597: WARNING: Inline literal start-string without end-string.
   Documentation/security/keys/core.rst:1597: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1597: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1598: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1598: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1600: WARNING: Inline literal start-string without end-string.
   Documentation/security/keys/core.rst:1600: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1600: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1600: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1600: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1666: WARNING: Inline literal start-string without end-string.
   Documentation/security/keys/core.rst:1666: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1666: WARNING: Inline emphasis start-string without end-string.
   Documentation/security/keys/core.rst:1666: WARNING: Inline emphasis start-string without end-string.

Fix it by using a code-block instead.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-08 13:42:11 -06:00
Mauro Carvalho Chehab 6ad8b21652 docs: security: trusted-encrypted.rst: fix code-block tag
The code-block tag is at the wrong place, causing those
warnings:

    Documentation/security/keys/trusted-encrypted.rst:112: WARNING: Literal block expected; none found.
    Documentation/security/keys/trusted-encrypted.rst:121: WARNING: Unexpected indentation.
    Documentation/security/keys/trusted-encrypted.rst:122: WARNING: Block quote ends without a blank line; unexpected unindent.
    Documentation/security/keys/trusted-encrypted.rst:123: WARNING: Block quote ends without a blank line; unexpected unindent.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-08 13:42:11 -06:00
David Howells ed0ac5c7ec keys: Add a keyctl to move a key between keyrings
Add a keyctl to atomically move a link to a key from one keyring to
another.  The key must exist in "from" keyring and a flag can be given to
cause the operation to fail if there's a matching key already in the "to"
keyring.

This can be done with:

	keyctl(KEYCTL_MOVE,
	       key_serial_t key,
	       key_serial_t from_keyring,
	       key_serial_t to_keyring,
	       unsigned int flags);

The key being moved must grant Link permission and both keyrings must grant
Write permission.

flags should be 0 or KEYCTL_MOVE_EXCL, with the latter preventing
displacement of a matching key from the "to" keyring.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-05-30 22:44:48 +01:00
Linus Torvalds f218a29c25 Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull integrity updates from James Morris:
 "In Linux 4.19, a new LSM hook named security_kernel_load_data was
  upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
  Different signature verification methods exist for verifying the
  kexec'ed kernel image. This adds additional support in IMA to prevent
  loading unsigned kernel images via the kexec_load syscall,
  independently of the IMA policy rules, based on the runtime "secure
  boot" flag. An initial IMA kselftest is included.

  In addition, this pull request defines a new, separate keyring named
  ".platform" for storing the preboot/firmware keys needed for verifying
  the kexec'ed kernel image's signature and includes the associated IMA
  kexec usage of the ".platform" keyring.

  (David Howell's and Josh Boyer's patches for reading the
  preboot/firmware keys, which were previously posted for a different
  use case scenario, are included here)"

* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  integrity: Remove references to module keyring
  ima: Use inode_is_open_for_write
  ima: Support platform keyring for kernel appraisal
  efi: Allow the "db" UEFI variable to be suppressed
  efi: Import certificates from UEFI Secure Boot
  efi: Add an EFI signature blob parser
  efi: Add EFI signature data types
  integrity: Load certs to the platform keyring
  integrity: Define a trusted platform keyring
  selftests/ima: kexec_load syscall test
  ima: don't measure/appraise files on efivarfs
  x86/ima: retry detecting secure boot mode
  docs: Extend trusted keys documentation for TPM 2.0
  x86/ima: define arch_get_ima_policy() for x86
  ima: add support for arch specific policies
  ima: refactor ima_init_policy()
  ima: prevent kexec_load syscall based on runtime secureboot flag
  x86/ima: define arch_ima_get_secureboot
  integrity: support new struct public_key_signature encoding field
2019-01-02 09:43:14 -08:00
Linus Torvalds 3868772b99 A fairly normal cycle for documentation stuff. We have a new
document on perf security, more Italian translations, more
 improvements to the memory-management docs, improvements to the
 pathname lookup documentation, and the usual array of smaller
 fixes.
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Merge tag 'docs-5.0' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "A fairly normal cycle for documentation stuff. We have a new document
  on perf security, more Italian translations, more improvements to the
  memory-management docs, improvements to the pathname lookup
  documentation, and the usual array of smaller fixes.

  As is often the case, there are a few reaches outside of
  Documentation/ to adjust kerneldoc comments"

* tag 'docs-5.0' of git://git.lwn.net/linux: (38 commits)
  docs: improve pathname-lookup document structure
  configfs: fix wrong name of struct in documentation
  docs/mm-api: link slab_common.c to "The Slab Cache" section
  slab: make kmem_cache_create{_usercopy} description proper kernel-doc
  doc:process: add links where missing
  docs/core-api: make mm-api.rst more structured
  x86, boot: documentation whitespace fixup
  Documentation: devres: note checking needs when converting
  doc🇮🇹 add some process/* translations
  doc🇮🇹 fixes in process/1.Intro
  Documentation: convert path-lookup from markdown to resturctured text
  Documentation/admin-guide: update admin-guide index.rst
  Documentation/admin-guide: introduce perf-security.rst file
  scripts/kernel-doc: Fix struct and struct field attribute processing
  Documentation: dev-tools: Fix typos in index.rst
  Correct gen_init_cpio tool's documentation
  Document /proc/pid PID reuse behavior
  Documentation: update path-lookup.md for parallel lookups
  Documentation: Use "while" instead of "whilst"
  dmaengine: Add mailing list address to the documentation
  ...
2018-12-29 11:21:49 -08:00
Dave Jiang 9db67581b9 keys-encrypted: add nvdimm key format type to encrypted keys
Adding nvdimm key format type to encrypted keys in order to limit the size
of the key to 32bytes.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-12-13 17:54:13 -08:00
Stefan Berger 4264f27a08 docs: Extend trusted keys documentation for TPM 2.0
Extend the documentation for trusted keys with documentation for how to
set up a key for a TPM 2.0 so it can be used with a TPM 2.0 as well.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-11 07:13:42 -05:00
Will Deacon 806654a966 Documentation: Use "while" instead of "whilst"
Whilst making an unrelated change to some Documentation, Linus sayeth:

  | Afaik, even in Britain, "whilst" is unusual and considered more
  | formal, and "while" is the common word.
  |
  | [...]
  |
  | Can we just admit that we work with computers, and we don't need to
  | use þe eald Englisc spelling of words that most of the world never
  | uses?

dictionary.com refers to the word as "Chiefly British", which is
probably an undesirable attribute for technical documentation.

Replace all occurrences under Documentation/ with "while".

Cc: David Howells <dhowells@redhat.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michael Halcrow <mhalcrow@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-11-20 09:30:43 -07:00
David Howells 00d60fd3b9 KEYS: Provide keyctls to drive the new key type ops for asymmetric keys [ver #2]
Provide five keyctl functions that permit userspace to make use of the new
key type ops for accessing and driving asymmetric keys.

 (*) Query an asymmetric key.

	long keyctl(KEYCTL_PKEY_QUERY,
		    key_serial_t key, unsigned long reserved,
		    struct keyctl_pkey_query *info);

     Get information about an asymmetric key.  The information is returned
     in the keyctl_pkey_query struct:

	__u32	supported_ops;

     A bit mask of flags indicating which ops are supported.  This is
     constructed from a bitwise-OR of:

	KEYCTL_SUPPORTS_{ENCRYPT,DECRYPT,SIGN,VERIFY}

	__u32	key_size;

     The size in bits of the key.

	__u16	max_data_size;
	__u16	max_sig_size;
	__u16	max_enc_size;
	__u16	max_dec_size;

     The maximum sizes in bytes of a blob of data to be signed, a signature
     blob, a blob to be encrypted and a blob to be decrypted.

     reserved must be set to 0.  This is intended for future use to hand
     over one or more passphrases needed unlock a key.

     If successful, 0 is returned.  If the key is not an asymmetric key,
     EOPNOTSUPP is returned.

 (*) Encrypt, decrypt, sign or verify a blob using an asymmetric key.

	long keyctl(KEYCTL_PKEY_ENCRYPT,
		    const struct keyctl_pkey_params *params,
		    const char *info,
		    const void *in,
		    void *out);

	long keyctl(KEYCTL_PKEY_DECRYPT,
		    const struct keyctl_pkey_params *params,
		    const char *info,
		    const void *in,
		    void *out);

	long keyctl(KEYCTL_PKEY_SIGN,
		    const struct keyctl_pkey_params *params,
		    const char *info,
		    const void *in,
		    void *out);

	long keyctl(KEYCTL_PKEY_VERIFY,
		    const struct keyctl_pkey_params *params,
		    const char *info,
		    const void *in,
		    const void *in2);

     Use an asymmetric key to perform a public-key cryptographic operation
     a blob of data.

     The parameter block pointed to by params contains a number of integer
     values:

	__s32		key_id;
	__u32		in_len;
	__u32		out_len;
	__u32		in2_len;

     For a given operation, the in and out buffers are used as follows:

	Operation ID		in,in_len	out,out_len	in2,in2_len
	=======================	===============	===============	===========
	KEYCTL_PKEY_ENCRYPT	Raw data	Encrypted data	-
	KEYCTL_PKEY_DECRYPT	Encrypted data	Raw data	-
	KEYCTL_PKEY_SIGN	Raw data	Signature	-
	KEYCTL_PKEY_VERIFY	Raw data	-		Signature

     info is a string of key=value pairs that supply supplementary
     information.

     The __spare space in the parameter block must be set to 0.  This is
     intended, amongst other things, to allow the passing of passphrases
     required to unlock a key.

     If successful, encrypt, decrypt and sign all return the amount of data
     written into the output buffer.  Verification returns 0 on success.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Tested-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
David Howells 70025f84e5 KEYS: Provide key type operations for asymmetric key ops [ver #2]
Provide five new operations in the key_type struct that can be used to
provide access to asymmetric key operations.  These will be implemented for
the asymmetric key type in a later patch and may refer to a key retained in
RAM by the kernel or a key retained in crypto hardware.

     int (*asym_query)(const struct kernel_pkey_params *params,
		       struct kernel_pkey_query *info);
     int (*asym_eds_op)(struct kernel_pkey_params *params,
			const void *in, void *out);
     int (*asym_verify_signature)(struct kernel_pkey_params *params,
			          const void *in, const void *in2);

Since encrypt, decrypt and sign are identical in their interfaces, they're
rolled together in the asym_eds_op() operation and there's an operation ID
in the params argument to distinguish them.

Verify is different in that we supply the data and the signature instead
and get an error value (or 0) as the only result on the expectation that
this may well be how a hardware crypto device may work.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Tested-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
Felix Eckhofer ff34876377 doc: Fix acronym "FEKEK" in ecryptfs
"FEFEK" was incorrectly used as acronym for "File Encryption Key
Encryption Key". This replaces all occurences with "FEKEK".

Signed-off-by: Felix Eckhofer <felix@eckhofer.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-09-20 11:11:48 -06:00
Eric Biggers be543dd626 KEYS: fix in-kernel documentation for keyctl_read()
When keyctl_read() is passed a buffer that is too small, the behavior is
inconsistent.  Some key types will fill as much of the buffer as
possible, while others won't copy anything.  Moreover, the in-kernel
documentation contradicted the man page on this point.

Update the in-kernel documentation to say that this point is
unspecified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-15 16:38:44 +00:00
Tom Saeger c7f66400f5 Documentation: fix security related doc refs
Make security document refs valid.

Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-10-12 11:14:40 -06:00
Josh Holland 33c2f4ec98 docs: ReSTify table of contents in core.rst
Sphinx will now generate the table of contents automatically, which
avoids having the ToC getting out of sync with the rest of the document.

Signed-off-by: Josh Holland <anowlcalledjosh@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-08-30 15:27:58 -06:00
Josh Holland adf31eebd7 docs: Fix paths in security/keys
Several paths in the security/keys documentation were incorrect.

Signed-off-by: Josh Holland <anowlcalledjosh@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-08-24 13:10:58 -06:00
Mat Martineau 7228b66aaf KEYS: Add documentation for asymmetric keyring restrictions
Provide more specific examples of keyring restrictions as applied to
X.509 signature chain verification.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-07-14 11:01:38 +10:00
Jonathan Corbet 5ea787a7ec docs: Fix some formatting issues in request-key.rst
The white space in the big enumerated list was inconsistent, leading to
some strange formatting artifacts.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:46:25 -06:00
Kees Cook 5395d312df doc: ReSTify keys-trusted-encrypted.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:56 -06:00
Kees Cook 3db38ed768 doc: ReSTify keys-request-key.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:51 -06:00
Kees Cook 09f5412cc5 doc: ReSTify keys-ecryptfs.txt
Adjusts for ReST markup and moves under keys security devel index.

Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:47 -06:00
Kees Cook b68101a1e8 doc: ReSTify keys.txt
This creates a new section in the security development index for kernel
keys, and adjusts for ReST markup.

Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2017-05-18 10:33:42 -06:00