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>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SP800-56A defines the use of DH with key derivation function based on a
counter. The input to the KDF is defined as (DH shared secret || other
information). The value for the "other information" is to be provided by
the caller.
The KDF is implemented using the hash support from the kernel crypto API.
The implementation uses the symmetric hash support as the input to the
hash operation is usually very small. The caller is allowed to specify
the hash name that he wants to use to derive the key material allowing
the use of all supported hashes provided with the kernel crypto API.
As the KDF implements the proper truncation of the DH shared secret to
the requested size, this patch fills the caller buffer up to its size.
The patch is tested with a new test added to the keyutils user space
code which uses a CAVS test vector testing the compliance with
SP800-56A.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: David Howells <dhowells@redhat.com>
This adds userspace access to Diffie-Hellman computations through a
new keyctl() syscall command to calculate shared secrets or public
keys using input parameters stored in the keyring.
Input key ids are provided in a struct due to the current 5-arg limit
for the keyctl syscall. Only user keys are supported in order to avoid
exposing the content of logon or encrypted keys.
The output is written to the provided buffer, based on the assumption
that the values are only needed in userspace.
Future support for other types of key derivation would involve a new
command, like KEYCTL_ECDH_COMPUTE.
Once Diffie-Hellman support is included in the crypto API, this code
can be converted to use the crypto API to take advantage of possible
hardware acceleration and reduce redundant code.
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Add support for per-user_namespace registers of persistent per-UID kerberos
caches held within the kernel.
This allows the kerberos cache to be retained beyond the life of all a user's
processes so that the user's cron jobs can work.
The kerberos cache is envisioned as a keyring/key tree looking something like:
struct user_namespace
\___ .krb_cache keyring - The register
\___ _krb.0 keyring - Root's Kerberos cache
\___ _krb.5000 keyring - User 5000's Kerberos cache
\___ _krb.5001 keyring - User 5001's Kerberos cache
\___ tkt785 big_key - A ccache blob
\___ tkt12345 big_key - Another ccache blob
Or possibly:
struct user_namespace
\___ .krb_cache keyring - The register
\___ _krb.0 keyring - Root's Kerberos cache
\___ _krb.5000 keyring - User 5000's Kerberos cache
\___ _krb.5001 keyring - User 5001's Kerberos cache
\___ tkt785 keyring - A ccache
\___ krbtgt/REDHAT.COM@REDHAT.COM big_key
\___ http/REDHAT.COM@REDHAT.COM user
\___ afs/REDHAT.COM@REDHAT.COM user
\___ nfs/REDHAT.COM@REDHAT.COM user
\___ krbtgt/KERNEL.ORG@KERNEL.ORG big_key
\___ http/KERNEL.ORG@KERNEL.ORG big_key
What goes into a particular Kerberos cache is entirely up to userspace. Kernel
support is limited to giving you the Kerberos cache keyring that you want.
The user asks for their Kerberos cache by:
krb_cache = keyctl_get_krbcache(uid, dest_keyring);
The uid is -1 or the user's own UID for the user's own cache or the uid of some
other user's cache (requires CAP_SETUID). This permits rpc.gssd or whatever to
mess with the cache.
The cache returned is a keyring named "_krb.<uid>" that the possessor can read,
search, clear, invalidate, unlink from and add links to. Active LSMs get a
chance to rule on whether the caller is permitted to make a link.
Each uid's cache keyring is created when it first accessed and is given a
timeout that is extended each time this function is called so that the keyring
goes away after a while. The timeout is configurable by sysctl but defaults to
three days.
Each user_namespace struct gets a lazily-created keyring that serves as the
register. The cache keyrings are added to it. This means that standard key
search and garbage collection facilities are available.
The user_namespace struct's register goes away when it does and anything left
in it is then automatically gc'd.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Simo Sorce <simo@redhat.com>
cc: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cc: Eric W. Biederman <ebiederm@xmission.com>
Implement a big key type that can save its contents to tmpfs and thus
swapspace when memory is tight. This is useful for Kerberos ticket caches.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Simo Sorce <simo@redhat.com>
Reorganise the keys directory Makefile to put all the core bits together and
the type-specific bits after.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@us.ibm.com>
The 'encrypted' key type defines its own payload format which contains a
symmetric key randomly generated that cannot be used directly to mount
an eCryptfs filesystem, because it expects an authentication token
structure.
This patch introduces the new format 'ecryptfs' that allows to store an
authentication token structure inside the encrypted key payload containing
a randomly generated symmetric key, as the same for the format 'default'.
More details about the usage of encrypted keys with the eCryptfs
filesystem can be found in the file 'Documentation/keys-ecryptfs.txt'.
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Acked-by: Gianluca Ramunno <ramunno@polito.it>
Acked-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Rename encrypted_defined.c and encrypted_defined.h files to encrypted.c and
encrypted.h, respectively. Based on request from David Howells.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Rename trusted_defined.c and trusted_defined.h files to trusted.c and
trusted.h, respectively. Based on request from David Howells.
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Define a new kernel key-type called 'encrypted'. Encrypted keys are kernel
generated random numbers, which are encrypted/decrypted with a 'trusted'
symmetric key. Encrypted keys are created/encrypted/decrypted in the kernel.
Userspace only ever sees/stores encrypted blobs.
Changelog:
- bug fix: replaced master-key rcu based locking with semaphore
(reported by David Howells)
- Removed memset of crypto_shash_digest() digest output
- Replaced verification of 'key-type:key-desc' using strcspn(), with
one based on string constants.
- Moved documentation to Documentation/keys-trusted-encrypted.txt
- Replace hash with shash (based on comments by David Howells)
- Make lengths/counts size_t where possible (based on comments by David Howells)
Could not convert most lengths, as crypto expects 'unsigned int'
(size_t: on 32 bit is defined as unsigned int, but on 64 bit is unsigned long)
- Add 'const' where possible (based on comments by David Howells)
- allocate derived_buf dynamically to support arbitrary length master key
(fixed by Roberto Sassu)
- wait until late_initcall for crypto libraries to be registered
- cleanup security/Kconfig
- Add missing 'update' keyword (reported/fixed by Roberto Sassu)
- Free epayload on failure to create key (reported/fixed by Roberto Sassu)
- Increase the data size limit (requested by Roberto Sassu)
- Crypto return codes are always 0 on success and negative on failure,
remove unnecessary tests.
- Replaced kzalloc() with kmalloc()
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: David Safford <safford@watson.ibm.com>
Reviewed-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: James Morris <jmorris@namei.org>
Define a new kernel key-type called 'trusted'. Trusted keys are random
number symmetric keys, generated and RSA-sealed by the TPM. The TPM
only unseals the keys, if the boot PCRs and other criteria match.
Userspace can only ever see encrypted blobs.
Based on suggestions by Jason Gunthorpe, several new options have been
added to support additional usages.
The new options are:
migratable= designates that the key may/may not ever be updated
(resealed under a new key, new pcrinfo or new auth.)
pcrlock=n extends the designated PCR 'n' with a random value,
so that a key sealed to that PCR may not be unsealed
again until after a reboot.
keyhandle= specifies the sealing/unsealing key handle.
keyauth= specifies the sealing/unsealing key auth.
blobauth= specifies the sealed data auth.
Implementation of a kernel reserved locality for trusted keys will be
investigated for a possible future extension.
Changelog:
- Updated and added examples to Documentation/keys-trusted-encrypted.txt
- Moved generic TPM constants to include/linux/tpm_command.h
(David Howell's suggestion.)
- trusted_defined.c: replaced kzalloc with kmalloc, added pcrlock failure
error handling, added const qualifiers where appropriate.
- moved to late_initcall
- updated from hash to shash (suggestion by David Howells)
- reduced worst stack usage (tpm_seal) from 530 to 312 bytes
- moved documentation to Documentation directory (suggestion by David Howells)
- all the other code cleanups suggested by David Howells
- Add pcrlock CAP_SYS_ADMIN dependency (based on comment by Jason Gunthorpe)
- New options: migratable, pcrlock, keyhandle, keyauth, blobauth (based on
discussions with Jason Gunthorpe)
- Free payload on failure to create key(reported/fixed by Roberto Sassu)
- Updated Kconfig and other descriptions (based on Serge Hallyn's suggestion)
- Replaced kzalloc() with kmalloc() (reported by Serge Hallyn)
Signed-off-by: David Safford <safford@watson.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Add garbage collection for dead, revoked and expired keys. This involved
erasing all links to such keys from keyrings that point to them. At that
point, the key will be deleted in the normal manner.
Keyrings from which garbage collection occurs are shrunk and their quota
consumption reduced as appropriate.
Dead keys (for which the key type has been removed) will be garbage collected
immediately.
Revoked and expired keys will hang around for a number of seconds, as set in
/proc/sys/kernel/keys/gc_delay before being automatically removed. The default
is 5 minutes.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Make the keyring quotas controllable through /proc/sys files:
(*) /proc/sys/kernel/keys/root_maxkeys
/proc/sys/kernel/keys/root_maxbytes
Maximum number of keys that root may have and the maximum total number of
bytes of data that root may have stored in those keys.
(*) /proc/sys/kernel/keys/maxkeys
/proc/sys/kernel/keys/maxbytes
Maximum number of keys that each non-root user may have and the maximum
total number of bytes of data that each of those users may have stored in
their keys.
Also increase the quotas as a number of people have been complaining that it's
not big enough. I'm not sure that it's big enough now either, but on the
other hand, it can now be set in /etc/sysctl.conf.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The attached patch splits key permissions checking out of key-ui.h and
moves it into a .c file. It's quite large and called quite a lot, and
it's about to get bigger with the addition of LSM support for keys...
key_any_permission() is also discarded as it's no longer used.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The attached patch makes the following changes:
(1) There's a new special key type called ".request_key_auth".
This is an authorisation key for when one process requests a key and
another process is started to construct it. This type of key cannot be
created by the user; nor can it be requested by kernel services.
Authorisation keys hold two references:
(a) Each refers to a key being constructed. When the key being
constructed is instantiated the authorisation key is revoked,
rendering it of no further use.
(b) The "authorising process". This is either:
(i) the process that called request_key(), or:
(ii) if the process that called request_key() itself had an
authorisation key in its session keyring, then the authorising
process referred to by that authorisation key will also be
referred to by the new authorisation key.
This means that the process that initiated a chain of key requests
will authorise the lot of them, and will, by default, wind up with
the keys obtained from them in its keyrings.
(2) request_key() creates an authorisation key which is then passed to
/sbin/request-key in as part of a new session keyring.
(3) When request_key() is searching for a key to hand back to the caller, if
it comes across an authorisation key in the session keyring of the
calling process, it will also search the keyrings of the process
specified therein and it will use the specified process's credentials
(fsuid, fsgid, groups) to do that rather than the calling process's
credentials.
This allows a process started by /sbin/request-key to find keys belonging
to the authorising process.
(4) A key can be read, even if the process executing KEYCTL_READ doesn't have
direct read or search permission if that key is contained within the
keyrings of a process specified by an authorisation key found within the
calling process's session keyring, and is searchable using the
credentials of the authorising process.
This allows a process started by /sbin/request-key to read keys belonging
to the authorising process.
(5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or
KEYCTL_NEGATE will specify a keyring of the authorising process, rather
than the process doing the instantiation.
(6) One of the process keyrings can be nominated as the default to which
request_key() should attach new keys if not otherwise specified. This is
done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_*
constants. The current setting can also be read using this call.
(7) request_key() is partially interruptible. If it is waiting for another
process to finish constructing a key, it can be interrupted. This permits
a request-key cycle to be broken without recourse to rebooting.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
David Howells