Commit Graph

33 Commits

Author SHA1 Message Date
David Howells fd19a3d195 PKCS#7: Improve and export the X.509 ASN.1 time object decoder
Make the X.509 ASN.1 time object decoder fill in a time64_t rather than a
struct tm to make comparison easier (unfortunately, this makes readable
display less easy) and export it so that it can be used by the PKCS#7 code
too.

Further, tighten up its parsing to reject invalid dates (eg. weird
characters, non-existent hour numbers) and unsupported dates (eg. timezones
other than 'Z' or dates earlier than 1970).

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
2015-08-12 17:01:01 +01:00
David Howells 4573b64a31 X.509: Support X.509 lookup by Issuer+Serial form AuthorityKeyIdentifier
If an X.509 certificate has an AuthorityKeyIdentifier extension that provides
an issuer and serialNumber, then make it so that these are used in preference
to the keyIdentifier field also held therein for searching for the signing
certificate.

If both the issuer+serialNumber and the keyIdentifier are supplied, then the
certificate is looked up by the former but the latter is checked as well.  If
the latter doesn't match the subjectKeyIdentifier of the parent certificate,
EKEYREJECTED is returned.

This makes it possible to chain X.509 certificates based on the issuer and
serialNumber fields rather than on subjectKeyIdentifier.  This is necessary as
we are having to deal with keys that are represented by X.509 certificates
that lack a subjectKeyIdentifier.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
2015-08-07 16:26:13 +01:00
David Howells b92e6570a9 X.509: Extract both parts of the AuthorityKeyIdentifier
Extract both parts of the AuthorityKeyIdentifier, not just the keyIdentifier,
as the second part can be used to match X.509 certificates by issuer and
serialNumber.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
2015-08-07 16:26:13 +01:00
Mimi Zohar f2b3dee484 KEYS: fix "ca_keys=" partial key matching
The call to asymmetric_key_hex_to_key_id() from ca_keys_setup()
silently fails with -ENOMEM.  Instead of dynamically allocating
memory from a __setup function, this patch defines a variable
and calls __asymmetric_key_hex_to_key_id(), a new helper function,
directly.

This bug was introduced by 'commit 46963b774d ("KEYS: Overhaul
key identification when searching for asymmetric keys")'.

Changelog:
- for clarification, rename hexlen to asciihexlen in
  asymmetric_key_hex_to_key_id()
- add size argument to __asymmetric_key_hex_to_key_id() - David Howells
- inline __asymmetric_key_hex_to_key_id() - David Howells
- remove duplicate strlen() calls

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # 3.18
2015-05-21 13:58:59 -04:00
Dmitry Kasatkin 7a224e783a KEYS: strip 'id:' from ca_keyid
The 'id:' prefix must be stripped for asymmetric_key_hex_to_key_id() to be
able to process ca_keyid.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-10-06 17:33:27 +01:00
Dmitry Kasatkin f1b731dbc2 KEYS: Restore partial ID matching functionality for asymmetric keys
Bring back the functionality whereby an asymmetric key can be matched with a
partial match on one of its IDs.

Whilst we're at it, allow for the possibility of having an increased number of
IDs.

Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-10-06 15:21:05 +01:00
David Howells dd2f6c4481 X.509: If available, use the raw subjKeyId to form the key description
Module signing matches keys by comparing against the key description exactly.
However, the way the key description gets constructed got changed to be
composed of the subject name plus the certificate serial number instead of the
subject name and the subjectKeyId.  I changed this to avoid problems with
certificates that don't *have* a subjectKeyId.

Instead, if available, use the raw subjectKeyId to form the key description
and only use the serial number if the subjectKeyId doesn't exist.

Reported-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-10-03 16:17:02 +01:00
David Howells 4155942000 PKCS#7: Better handling of unsupported crypto
Provide better handling of unsupported crypto when verifying a PKCS#7 message.
If we can't bridge the gap between a pair of X.509 certs or between a signed
info block and an X.509 cert because it involves some crypto we don't support,
that's not necessarily the end of the world as there may be other ways points
at which we can intersect with a ring of trusted keys.

Instead, only produce ENOPKG immediately if all the signed info blocks in a
PKCS#7 message require unsupported crypto to bridge to the first X.509 cert.
Otherwise, we defer the generation of ENOPKG until we get ENOKEY during trust
validation.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16 17:36:15 +01:00
David Howells 46963b774d KEYS: Overhaul key identification when searching for asymmetric keys
Make use of the new match string preparsing to overhaul key identification
when searching for asymmetric keys.  The following changes are made:

 (1) Use the previously created asymmetric_key_id struct to hold the following
     key IDs derived from the X.509 certificate or PKCS#7 message:

	id: serial number + issuer
	skid: subjKeyId + subject
	authority: authKeyId + issuer

 (2) Replace the hex fingerprint attached to key->type_data[1] with an
     asymmetric_key_ids struct containing the id and the skid (if present).

 (3) Make the asymmetric_type match data preparse select one of two searches:

     (a) An iterative search for the key ID given if prefixed with "id:".  The
     	 prefix is expected to be followed by a hex string giving the ID to
     	 search for.  The criterion key ID is checked against all key IDs
     	 recorded on the key.

     (b) A direct search if the key ID is not prefixed with "id:".  This will
     	 look for an exact match on the key description.

 (4) Make x509_request_asymmetric_key() take a key ID.  This is then converted
     into "id:<hex>" and passed into keyring_search() where match preparsing
     will turn it back into a binary ID.

 (5) X.509 certificate verification then takes the authority key ID and looks
     up a key that matches it to find the public key for the certificate
     signature.

 (6) PKCS#7 certificate verification then takes the id key ID and looks up a
     key that matches it to find the public key for the signed information
     block signature.

Additional changes:

 (1) Multiple subjKeyId and authKeyId values on an X.509 certificate cause the
     cert to be rejected with -EBADMSG.

 (2) The 'fingerprint' ID is gone.  This was primarily intended to convey PGP
     public key fingerprints.  If PGP is supported in future, this should
     generate a key ID that carries the fingerprint.

 (3) Th ca_keyid= kernel command line option is now converted to a key ID and
     used to match the authority key ID.  Possibly this should only match the
     actual authKeyId part and not the issuer as well.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
2014-09-16 17:36:13 +01:00
David Howells cf5b50fd2d X.509: Need to export x509_request_asymmetric_key()
Need to export x509_request_asymmetric_key() so that PKCS#7 can use it if
compiled as a module.

Reported-by: James Morris <jmorris@namei.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2014-08-03 12:54:48 +01:00
David Howells 5ce43ad282 PKCS#7: Use x509_request_asymmetric_key()
pkcs7_request_asymmetric_key() and x509_request_asymmetric_key() do the same
thing, the latter being a copy of the former created by the IMA folks, so drop
the PKCS#7 version as the X.509 location is more general.

Whilst we're at it, rename the arguments of x509_request_asymmetric_key() to
better reflect what the values being passed in are intended to match on an
X.509 cert.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-29 13:07:58 +01:00
David Howells 185de09c6a X.509: x509_request_asymmetric_keys() doesn't need string length arguments
x509_request_asymmetric_keys() doesn't need the lengths of the NUL-terminated
strings passing in as it can work that out for itself.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-28 14:55:55 +01:00
David Howells 64724cfc6e Merge remote-tracking branch 'integrity/next-with-keys' into keys-next
Signed-off-by: David Howells <dhowells@redhat.com>
2014-07-22 21:54:43 +01:00
David Howells fc7c70e0b6 KEYS: struct key_preparsed_payload should have two payload pointers
struct key_preparsed_payload should have two payload pointers to correspond
with those in struct key.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Sage Weil <sage@redhat.com>
2014-07-22 21:46:02 +01:00
Dmitry Kasatkin 32c4741cb6 KEYS: validate certificate trust only with builtin keys
Instead of allowing public keys, with certificates signed by any
key on the system trusted keyring, to be added to a trusted keyring,
this patch further restricts the certificates to those signed only by
builtin keys on the system keyring.

This patch defines a new option 'builtin' for the kernel parameter
'keys_ownerid' to allow trust validation using builtin keys.

Simplified Mimi's "KEYS: define an owner trusted keyring" patch

Changelog v7:
- rename builtin_keys to use_builtin_keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:17 -04:00
Dmitry Kasatkin ffb70f61ba KEYS: validate certificate trust only with selected key
Instead of allowing public keys, with certificates signed by any
key on the system trusted keyring, to be added to a trusted keyring,
this patch further restricts the certificates to those signed by a
particular key on the system keyring.

This patch defines a new kernel parameter 'ca_keys' to identify the
specific key which must be used for trust validation of certificates.

Simplified Mimi's "KEYS: define an owner trusted keyring" patch.

Changelog:
- support for builtin x509 public keys only
- export "asymmetric_keyid_match"
- remove ifndefs MODULE
- rename kernel boot parameter from keys_ownerid to ca_keys

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-07-17 09:35:16 -04:00
Mimi Zohar 3be4beaf7c KEYS: verify a certificate is signed by a 'trusted' key
Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring.  This patch adds support for verifying
a certificate's signature.

This is derived from David Howells pkcs7_request_asymmetric_key() patch.

Changelog v6:
- on error free key - Dmitry
- validate trust only for not already trusted keys - Dmitry
- formatting cleanup

Changelog:
- define get_system_trusted_keyring() to fix kbuild issues

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
2014-07-17 09:35:15 -04:00
Linus Torvalds 4c1cc40a2d Revert "KEYS: verify a certificate is signed by a 'trusted' key"
This reverts commit 09fbc47373, which
caused the following build errors:

  crypto/asymmetric_keys/x509_public_key.c: In function ‘x509_key_preparse’:
  crypto/asymmetric_keys/x509_public_key.c:237:35: error: ‘system_trusted_keyring’ undeclared (first use in this function)
   ret = x509_validate_trust(cert, system_trusted_keyring);
                                   ^
  crypto/asymmetric_keys/x509_public_key.c:237:35: note: each undeclared identifier is reported only once for each function it appears in

reported by Jim Davis. Mimi says:

 "I made the classic mistake of requesting this patch to be upstreamed
  at the last second, rather than waiting until the next open window.

  At this point, the best course would probably be to revert the two
  commits and fix them for the next open window"

Reported-by: Jim Davis <jim.epost@gmail.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-23 16:38:17 -08:00
Dmitry Kasatkin c7c8bb237f ima: provide support for arbitrary hash algorithms
In preparation of supporting more hash algorithms with larger hash sizes
needed for signature verification, this patch replaces the 20 byte sized
digest, with a more flexible structure.  The new structure includes the
hash algorithm, digest size, and digest.

Changelog:
- recalculate filedata hash for the measurement list, if the signature
  hash digest size is greater than 20 bytes.
- use generic HASH_ALGO_
- make ima_calc_file_hash static
- scripts lindent and checkpatch fixes

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:16:58 -04:00
Dmitry Kasatkin 3fe78ca2fb keys: change asymmetric keys to use common hash definitions
This patch makes use of the newly defined common hash algorithm info,
replacing, for example, PKEY_HASH with HASH_ALGO.

Changelog:
- Lindent fixes - Mimi

CC: David Howells <dhowells@redhat.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2013-10-25 17:15:18 -04:00
Konstantin Khlebnikov e19aaa7d43 X.509: add module description and license
This patch fixes lack of license, otherwise x509_key_parser.ko taints kernel.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-25 17:17:01 +01:00
Mimi Zohar 09fbc47373 KEYS: verify a certificate is signed by a 'trusted' key
Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring.  This patch adds support for verifying
a certificate's signature.

This is derived from David Howells pkcs7_request_asymmetric_key() patch.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-25 17:17:01 +01:00
David Howells 124df92609 X.509: Remove certificate date checks
Remove the certificate date checks that are performed when a certificate is
parsed.  There are two checks: a valid from and a valid to.  The first check is
causing a lot of problems with system clocks that don't keep good time and the
second places an implicit expiry date upon the kernel when used for module
signing, so do we really need them?

Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Rusty Russell <rusty@rustcorp.com.au>
cc: Josh Boyer <jwboyer@redhat.com>
cc: Alexander Holler <holler@ahsoftware.de>
cc: stable@vger.kernel.org
2013-09-25 17:17:01 +01:00
David Howells 17334cabc8 X.509: Handle certificates that lack an authorityKeyIdentifier field
Handle certificates that lack an authorityKeyIdentifier field by assuming
they're self-signed and checking their signatures against themselves.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 17:17:01 +01:00
David Howells 2ecdb23b8c X.509: Check the algorithm IDs obtained from parsing an X.509 certificate
Check that the algorithm IDs obtained from the ASN.1 parse by OID lookup
corresponds to algorithms that are available to us.

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-25 17:17:01 +01:00
David Howells b426beb6ee X.509: Embed public_key_signature struct and create filler function
Embed a public_key_signature struct in struct x509_certificate, eliminating
now unnecessary fields, and split x509_check_signature() to create a filler
function for it that attaches a digest of the signed data and an MPI that
represents the signature data.  x509_free_certificate() is then modified to
deal with these.

Whilst we're at it, export both x509_check_signature() and the new
x509_get_sig_params().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 17:17:00 +01:00
David Howells 3d167d68e3 KEYS: Split public_key_verify_signature() and make available
Modify public_key_verify_signature() so that it now takes a public_key struct
rather than a key struct and supply a wrapper that takes a key struct.  The
wrapper is then used by the asymmetric key subtype and the modified function is
used by X.509 self-signature checking and can be used by other things also.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 17:17:00 +01:00
David Howells 67f7d60b3a KEYS: Store public key algo ID in public_key struct
Store public key algo ID in public_key struct for reference purposes.  This
allows it to be removed from the x509_certificate struct and used to find a
default in public_key_verify_signature().

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 17:17:00 +01:00
David Howells 206ce59a10 KEYS: Move the algorithm pointer array from x509 to public_key.c
Move the public-key algorithm pointer array from x509_public_key.c to
public_key.c as it isn't X.509 specific.

Note that to make this configure correctly, the public key part must be
dependent on the RSA module rather than the other way round.  This needs a
further patch to make use of the crypto module loading stuff rather than using
a fixed table.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 15:51:07 +01:00
David Howells 9abc4e66eb KEYS: Rename public key parameter name arrays
Rename the arrays of public key parameters (public key algorithm names, hash
algorithm names and ID type names) so that the array name ends in "_name".

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
2013-09-25 15:51:07 +01:00
David Howells 2f1c4fef10 X.509: Convert some printk calls to pr_devel
Some debugging printk() calls should've been converted to pr_devel() calls.
Do that now.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10 20:06:38 +10:30
David Howells a5752d11b3 MODSIGN: Fix 32-bit overflow in X.509 certificate validity date checking
The current choice of lifetime for the autogenerated X.509 of 100 years,
putting the validTo date in 2112, causes problems on 32-bit systems where a
32-bit time_t wraps in 2106.  64-bit x86_64 systems seem to be unaffected.

This can result in something like:

	Loading module verification certificates
	X.509: Cert 6e03943da0f3b015ba6ed7f5e0cac4fe48680994 has expired
	MODSIGN: Problem loading in-kernel X.509 certificate (-127)

Or:

	X.509: Cert 6e03943da0f3b015ba6ed7f5e0cac4fe48680994 is not yet valid
	MODSIGN: Problem loading in-kernel X.509 certificate (-129)

Instead of turning the dates into time_t values and comparing, turn the system
clock and the ASN.1 dates into tm structs and compare those piecemeal instead.

Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Josh Boyer <jwboyer@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-10 20:06:37 +10:30
David Howells c26fd69fa0 X.509: Add a crypto key parser for binary (DER) X.509 certificates
Add a crypto key parser for binary (DER) encoded X.509 certificates.  The
certificate is parsed and, if possible, the signature is verified.

An X.509 key can be added like this:

	# keyctl padd crypto bar @s </tmp/x509.cert
	15768135

and displayed like this:

	# cat /proc/keys
	00f09a47 I--Q---     1 perm 39390000     0     0 asymmetri bar: X509.RSA e9fd6d08 []

Note that this only works with binary certificates.  PEM encoded certificates
are ignored by the parser.

Note also that the X.509 key ID is not congruent with the PGP key ID, but for
the moment, they will match.

If a NULL or "" name is given to add_key(), then the parser will generate a key
description from the CertificateSerialNumber and Name fields of the
TBSCertificate:

	00aefc4e I--Q---     1 perm 39390000     0     0 asymmetri bfbc0cd76d050ea4:/C=GB/L=Cambridge/O=Red Hat/CN=kernel key: X509.RSA 0c688c7b []

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-08 13:50:22 +10:30