Commit Graph

162 Commits

Author SHA1 Message Date
Eric Sesterhenn 68a1fdbbf8 pkcs7: Prevent NULL pointer dereference, since sinfo is not always set.
The ASN.1 parser does not necessarily set the sinfo field,
this patch prevents a NULL pointer dereference on broken
input.

Fixes: 99db443506 ("PKCS#7: Appropriately restrict authenticated attributes and content type")
Signed-off-by: Eric Sesterhenn <eric.sesterhenn@x41-dsec.de>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org # 4.3+
2017-10-18 09:12:41 +01:00
Chun-Yi Lee b3811d36a3 KEYS: checking the input id parameters before finding asymmetric key
For finding asymmetric key, the input id_0 and id_1 parameters can
not be NULL at the same time. This patch adds the BUG_ON checking
for id_0 and id_1.

Cc: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18 09:12:40 +01:00
Chun-Yi Lee 6a6d2a77ad KEYS: Fix the wrong index when checking the existence of second id
Fix the wrong index number when checking the existence of second
id in function of finding asymmetric key. The id_1 is the second
id that the index in array must be 1 but not 0.

Fixes: 9eb029893a (KEYS: Generalise x509_request_asymmetric_key())
Cc: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-10-18 09:12:40 +01:00
Loganaden Velvindron da7798a7b6 crypto : asymmetric_keys : verify_pefile:zero memory content before freeing
Signed-off-by: Loganaden Velvindron <logan@hackers.mu>
Signed-off-by: Yasir Auleear <yasirmx@hackers.mu>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:50 +10:00
Dan Carpenter 4e880168e9 X.509: Fix error code in x509_cert_parse()
We forgot to set the error code on this path so it could result in
returning NULL which leads to a NULL dereference.

Fixes: db6c43bd21 ("crypto: KEYS: convert public key and digsig asym to the akcipher api")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-06-09 13:29:45 +10:00
Gilad Ben-Yossef e68368aed5 crypto: asymmetric_keys - handle EBUSY due to backlog correctly
public_key_verify_signature() was passing the CRYPTO_TFM_REQ_MAY_BACKLOG
flag to akcipher_request_set_callback() but was not handling correctly
the case where a -EBUSY error could be returned from the call to
crypto_akcipher_verify() if backlog was used, possibly casuing
data corruption due to use-after-free of buffers.

Resolve this by handling -EBUSY correctly.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-05-23 12:45:10 +08:00
Mat Martineau 8e323a02e8 KEYS: Keyring asymmetric key restrict method with chaining
Add a restrict_link_by_key_or_keyring_chain link restriction that
searches for signing keys in the destination keyring in addition to the
signing key or keyring designated when the destination keyring was
created. Userspace enables this behavior by including the "chain" option
in the keyring restriction:

  keyctl(KEYCTL_RESTRICT_KEYRING, keyring, "asymmetric",
         "key_or_keyring:<signing key>:chain");

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-04 14:10:13 -07:00
Mat Martineau 7e3c4d2208 KEYS: Restrict asymmetric key linkage using a specific keychain
Adds restrict_link_by_signature_keyring(), which uses the restrict_key
member of the provided destination_keyring data structure as the
key or keyring to search for signing keys.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-04 14:10:13 -07:00
Mat Martineau 97d3aa0f31 KEYS: Add a lookup_restriction function for the asymmetric key type
Look up asymmetric keyring restriction information using the key-type
lookup_restrict hook.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-04 14:10:12 -07:00
Mat Martineau aaf66c8838 KEYS: Split role of the keyring pointer for keyring restrict functions
The first argument to the restrict_link_func_t functions was a keyring
pointer. These functions are called by the key subsystem with this
argument set to the destination keyring, but restrict_link_by_signature
expects a pointer to the relevant trusted keyring.

Restrict functions may need something other than a single struct key
pointer to allow or reject key linkage, so the data used to make that
decision (such as the trust keyring) is moved to a new, fourth
argument. The first argument is now always the destination keyring.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
2017-04-03 10:24:56 -07:00
David Howells 03bb79315d PKCS#7: Handle blacklisted certificates
PKCS#7: Handle certificates that are blacklisted when verifying the chain
of trust on the signatures on a PKCS#7 message.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-03 16:07:25 +01:00
David Howells 436529562d X.509: Allow X.509 certs to be blacklisted
Allow X.509 certs to be blacklisted based on their TBSCertificate hash.
This is convenient since we have to determine this anyway to be able to
check the signature on an X.509 certificate.  This is also what UEFI uses
in its blacklist.

If a certificate built into the kernel is blacklisted, something like the
following might then be seen during boot:

	X.509: Cert 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46 is blacklisted
	Problem loading in-kernel X.509 certificate (-129)

where the hex string shown is the blacklisted hash.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-04-03 16:07:25 +01:00
Linus Torvalds 19c75bcbe0 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - a crash regression in the new skcipher walker

   - incorrect return value in public_key_verify_signature

   - fix for in-place signing in the sign-file utility"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: skcipher - fix crash in virtual walk
  sign-file: Fix inplace signing when src and dst names are both specified
  crypto: asymmetric_keys - set error code on failure
2016-12-15 11:41:37 -08:00
Pan Bian fbb726302a crypto: asymmetric_keys - set error code on failure
In function public_key_verify_signature(), returns variable ret on
error paths. When the call to kmalloc() fails, the value of ret is 0,
and it is not set to an errno before returning. This patch fixes the
bug.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188891

Signed-off-by: Pan Bian <bianpan2016@163.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-12-14 18:33:13 +08:00
Andrey Ryabinin 2b95fda2c4 X.509: Fix double free in x509_cert_parse() [ver #3]
We shouldn't free cert->pub->key in x509_cert_parse() because
x509_free_certificate() also does this:
	BUG: Double free or freeing an invalid pointer
	...
	Call Trace:
	 [<ffffffff81896c20>] dump_stack+0x63/0x83
	 [<ffffffff81356571>] kasan_object_err+0x21/0x70
	 [<ffffffff81356ed9>] kasan_report_double_free+0x49/0x60
	 [<ffffffff813561ad>] kasan_slab_free+0x9d/0xc0
	 [<ffffffff81350b7a>] kfree+0x8a/0x1a0
	 [<ffffffff81844fbf>] public_key_free+0x1f/0x30
	 [<ffffffff818455d4>] x509_free_certificate+0x24/0x90
	 [<ffffffff818460bc>] x509_cert_parse+0x2bc/0x300
	 [<ffffffff81846cae>] x509_key_preparse+0x3e/0x330
	 [<ffffffff818444cf>] asymmetric_key_preparse+0x6f/0x100
	 [<ffffffff8178bec0>] key_create_or_update+0x260/0x5f0
	 [<ffffffff8178e6d9>] SyS_add_key+0x199/0x2a0
	 [<ffffffff821d823b>] entry_SYSCALL_64_fastpath+0x1e/0xad
	Object at ffff880110bd1900, in cache kmalloc-512 size: 512
	....
	Freed:
	PID = 2579
	[<ffffffff8104283b>] save_stack_trace+0x1b/0x20
	[<ffffffff813558f6>] save_stack+0x46/0xd0
	[<ffffffff81356183>] kasan_slab_free+0x73/0xc0
	[<ffffffff81350b7a>] kfree+0x8a/0x1a0
	[<ffffffff818460a3>] x509_cert_parse+0x2a3/0x300
	[<ffffffff81846cae>] x509_key_preparse+0x3e/0x330
	[<ffffffff818444cf>] asymmetric_key_preparse+0x6f/0x100
	[<ffffffff8178bec0>] key_create_or_update+0x260/0x5f0
	[<ffffffff8178e6d9>] SyS_add_key+0x199/0x2a0
	[<ffffffff821d823b>] entry_SYSCALL_64_fastpath+0x1e/0xad

Fixes: db6c43bd21 ("crypto: KEYS: convert public key and digsig asym to the akcipher api")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-11-25 12:57:48 +11:00
Mat Martineau acddc72015 KEYS: Fix for erroneous trust of incorrectly signed X.509 certs
Arbitrary X.509 certificates without authority key identifiers (AKIs)
can be added to "trusted" keyrings, including IMA or EVM certs loaded
from the filesystem. Signature verification is currently bypassed for
certs without AKIs.

Trusted keys were recently refactored, and this bug is not present in
4.6.

restrict_link_by_signature should return -ENOKEY (no matching parent
certificate found) if the certificate being evaluated has no AKIs,
instead of bypassing signature checks and returning 0 (new certificate
accepted).

Reported-by: Petko Manolov <petkan@mip-labs.com>
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>
2016-07-18 12:19:47 +10:00
Lans Zhang d128471a14 pefile: Fix the failure of calculation for digest
Commit e68503bd68 forgot to set digest_len and thus cause the following
error reported by kexec when launching a crash kernel:

	kexec_file_load failed: Bad message

Fixes: e68503bd68 (KEYS: Generalise system_verify_data() to provide access to internal content)
Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
cc: kexec@lists.infradead.org
cc: linux-crypto@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-18 12:19:46 +10:00
Lans Zhang a46e667887 PKCS#7: Fix panic when referring to the empty AKID when DEBUG defined
This fix resolves the following kernel panic if an empty or missing
AuthorityKeyIdentifier is encountered and DEBUG is defined in
pkcs7_verify.c.

[  459.041989] PKEY: <==public_key_verify_signature() = 0
[  459.041993] PKCS7: Verified signature 1
[  459.041995] PKCS7: ==> pkcs7_verify_sig_chain()
[  459.041999] PKCS7: verify Sample DB Certificate for SCP: 01
[  459.042002] PKCS7: - issuer Sample KEK Certificate for SCP
[  459.042014] BUG: unable to handle kernel NULL pointer dereference at           (null)
[  459.042135] IP: [<ffffffff813e7b4c>] pkcs7_verify+0x72c/0x7f0
[  459.042217] PGD 739e6067 PUD 77719067 PMD 0
[  459.042286] Oops: 0000 [#1] PREEMPT SMP
[  459.042328] Modules linked in:
[  459.042368] CPU: 0 PID: 474 Comm: kexec Not tainted 4.7.0-rc7-WR8.0.0.0_standard+ #18
[  459.042462] Hardware name: To be filled by O.E.M. To be filled by O.E.M./Aptio CRB, BIOS 5.6.5 10/09/2014
[  459.042586] task: ffff880073a50000 ti: ffff8800738e8000 task.ti: ffff8800738e8000
[  459.042675] RIP: 0010:[<ffffffff813e7b4c>]  [<ffffffff813e7b4c>] pkcs7_verify+0x72c/0x7f0
[  459.042784] RSP: 0018:ffff8800738ebd58  EFLAGS: 00010246
[  459.042845] RAX: 0000000000000000 RBX: ffff880076b7da80 RCX: 0000000000000006
[  459.042929] RDX: 0000000000000001 RSI: ffffffff81c85001 RDI: ffffffff81ca00a9
[  459.043014] RBP: ffff8800738ebd98 R08: 0000000000000400 R09: ffff8800788a304c
[  459.043098] R10: 0000000000000000 R11: 00000000000060ca R12: ffff8800769a2bc0
[  459.043182] R13: ffff880077358300 R14: 0000000000000000 R15: ffff8800769a2dc0
[  459.043268] FS:  00007f24cc741700(0000) GS:ffff880074e00000(0000) knlGS:0000000000000000
[  459.043365] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  459.043431] CR2: 0000000000000000 CR3: 0000000073a36000 CR4: 00000000001006f0
[  459.043514] Stack:
[  459.043530]  0000000000000000 ffffffbf00000020 31ffffff813e68b0 0000000000000002
[  459.043644]  ffff8800769a2bc0 0000000000000000 00000000007197b8 0000000000000002
[  459.043756]  ffff8800738ebdd8 ffffffff81153fb1 0000000000000000 0000000000000000
[  459.043869] Call Trace:
[  459.043898]  [<ffffffff81153fb1>] verify_pkcs7_signature+0x61/0x140
[  459.043974]  [<ffffffff813e7f0b>] verify_pefile_signature+0x2cb/0x830
[  459.044052]  [<ffffffff813e8470>] ? verify_pefile_signature+0x830/0x830
[  459.044134]  [<ffffffff81048e25>] bzImage64_verify_sig+0x15/0x20
[  459.046332]  [<ffffffff81046e09>] arch_kexec_kernel_verify_sig+0x29/0x40
[  459.048552]  [<ffffffff810f10e4>] SyS_kexec_file_load+0x1f4/0x6c0
[  459.050768]  [<ffffffff81050e36>] ? __do_page_fault+0x1b6/0x550
[  459.052996]  [<ffffffff8199241f>] entry_SYSCALL_64_fastpath+0x17/0x93
[  459.055242] Code: e8 0a d6 ff ff 85 c0 0f 88 7a fb ff ff 4d 39 fd 4d 89 7d 08 74 45 4d 89 fd e9 14 fe ff ff 4d 8b 76 08 31 c0 48 c7 c7 a9 00 ca 81 <41> 0f b7 36 49 8d 56 02 e8 d0 91 d6 ff 4d 8b 3c 24 4d 85 ff 0f
[  459.060535] RIP  [<ffffffff813e7b4c>] pkcs7_verify+0x72c/0x7f0
[  459.063040]  RSP <ffff8800738ebd58>
[  459.065456] CR2: 0000000000000000
[  459.075998] ---[ end trace c15f0e897cda28dc ]---

Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
cc: linux-crypto@vger.kernel.org
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-07-18 12:19:44 +10:00
Linus Torvalds 446985428d Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - missing selection in public_key that may result in a build failure

   - Potential crash in error path in omap-sham

   - ccp AES XTS bug that affects requests larger than 4096"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: ccp - Fix AES XTS error for request sizes above 4096
  crypto: public_key: select CRYPTO_AKCIPHER
  crypto: omap-sham - potential Oops on error in probe
2016-05-30 15:20:18 -07:00
Arnd Bergmann bad6a185b4 crypto: public_key: select CRYPTO_AKCIPHER
In some rare randconfig builds, we can end up with
ASYMMETRIC_PUBLIC_KEY_SUBTYPE enabled but CRYPTO_AKCIPHER disabled,
which fails to link because of the reference to crypto_alloc_akcipher:

crypto/built-in.o: In function `public_key_verify_signature':
:(.text+0x110e4): undefined reference to `crypto_alloc_akcipher'

This adds a Kconfig 'select' statement to ensure the dependency
is always there.

Cc: <stable@vger.kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-05-19 18:03:01 +08:00
David Howells 3c8f227871 KEYS: The PKCS#7 test key type should use the secondary keyring
The PKCS#7 test key type should use the secondary keyring instead of the
built-in keyring if available as the source of trustworthy keys.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-05-11 14:31:55 +01:00
David Howells a511e1af8b KEYS: Move the point of trust determination to __key_link()
Move the point at which a key is determined to be trustworthy to
__key_link() so that we use the contents of the keyring being linked in to
to determine whether the key being linked in is trusted or not.

What is 'trusted' then becomes a matter of what's in the keyring.

Currently, the test is done when the key is parsed, but given that at that
point we can only sensibly refer to the contents of the system trusted
keyring, we can only use that as the basis for working out the
trustworthiness of a new key.

With this change, a trusted keyring is a set of keys that once the
trusted-only flag is set cannot be added to except by verification through
one of the contained keys.

Further, adding a key into a trusted keyring, whilst it might grant
trustworthiness in the context of that keyring, does not automatically
grant trustworthiness in the context of a second keyring to which it could
be secondarily linked.

To accomplish this, the authentication data associated with the key source
must now be retained.  For an X.509 cert, this means the contents of the
AuthorityKeyIdentifier and the signature data.


If system keyrings are disabled then restrict_link_by_builtin_trusted()
resolves to restrict_link_reject().  The integrity digital signature code
still works correctly with this as it was previously using
KEY_FLAG_TRUSTED_ONLY, which doesn't permit anything to be added if there
is no system keyring against which trust can be determined.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:43:43 +01:00
David Howells 99716b7cae KEYS: Make the system trusted keyring depend on the asymmetric key type
Make the system trusted keyring depend on the asymmetric key type as
there's not a lot of point having it if you can't then load asymmetric keys
onto it.

This requires the ASYMMETRIC_KEY_TYPE to be made a bool, not a tristate, as
the Kconfig language doesn't then correctly force ASYMMETRIC_KEY_TYPE to
'y' rather than 'm' if SYSTEM_TRUSTED_KEYRING is 'y'.

Making SYSTEM_TRUSTED_KEYRING *select* ASYMMETRIC_KEY_TYPE instead doesn't
work as the Kconfig interpreter then wrongly complains about dependency
loops.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:43:24 +01:00
David Howells cfb664ff2b X.509: Move the trust validation code out to its own file
Move the X.509 trust validation code out to its own file so that it can be
generalised.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:42:55 +01:00
David Howells 5f7f5c81e5 X.509: Use verify_signature() if we have a struct key * to use
We should call verify_signature() rather than directly calling
public_key_verify_signature() if we have a struct key to use as we
shouldn't be poking around in the private data of the key struct as that's
subtype dependent.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:42:27 +01:00
David Howells 9eb029893a KEYS: Generalise x509_request_asymmetric_key()
Generalise x509_request_asymmetric_key().  It doesn't really have any
dependencies on X.509 features as it uses generalised IDs and the
public_key structs that contain data extracted from X.509.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:41:56 +01:00
David Howells 983023f28b KEYS: Move x509_request_asymmetric_key() to asymmetric_type.c
Move x509_request_asymmetric_key() to asymmetric_type.c so that it can be
generalised.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-11 22:41:28 +01:00
David Howells bda850cd21 PKCS#7: Make trust determination dependent on contents of trust keyring
Make the determination of the trustworthiness of a key dependent on whether
a key that can verify it is present in the supplied ring of trusted keys
rather than whether or not the verifying key has KEY_FLAG_TRUSTED set.

verify_pkcs7_signature() will return -ENOKEY if the PKCS#7 message trust
chain cannot be verified.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:14:24 +01:00
David Howells e68503bd68 KEYS: Generalise system_verify_data() to provide access to internal content
Generalise system_verify_data() to provide access to internal content
through a callback.  This allows all the PKCS#7 stuff to be hidden inside
this function and removed from the PE file parser and the PKCS#7 test key.

If external content is not required, NULL should be passed as data to the
function.  If the callback is not required, that can be set to NULL.

The function is now called verify_pkcs7_signature() to contrast with
verify_pefile_signature() and the definitions of both have been moved into
linux/verification.h along with the key_being_used_for enum.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:14:24 +01:00
David Howells ad3043fda3 X.509: Fix self-signed determination
There's a bug in the code determining whether a certificate is self-signed
or not: if they have neither AKID nor SKID then we just assume that the
cert is self-signed, which may not be true.

Fix this by checking that the raw subject name matches the raw issuer name
and that the public key algorithm for the key and signature are both the
same in addition to requiring that the AKID bits match.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:34 +01:00
David Howells 6c2dc5ae4a X.509: Extract signature digest and make self-signed cert checks earlier
Extract the signature digest for an X.509 certificate earlier, at the end
of x509_cert_parse() rather than leaving it to the callers thereof since it
has to be called anyway.

Further, immediately after that, check the signature on self-signed
certificates, also rather in the callers of x509_cert_parse().

We note in the x509_certificate struct the following bits of information:

 (1) Whether the signature is self-signed (even if we can't check the
     signature due to missing crypto).

 (2) Whether the key held in the certificate needs unsupported crypto to be
     used.  We may get a PKCS#7 message with X.509 certs that we can't make
     use of - we just ignore them and give ENOPKG at the end it we couldn't
     verify anything if at least one of these unusable certs are in the
     chain of trust.

 (3) Whether the signature held in the certificate needs unsupported crypto
     to be checked.  We can still use the key held in this certificate,
     even if we can't check the signature on it - if it is held in the
     system trusted keyring, for instance.  We just can't add it to a ring
     of trusted keys or follow it further up the chain of trust.

Making these checks earlier allows x509_check_signature() to be removed and
replaced with direct calls to public_key_verify_signature().

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:34 +01:00
David Howells 566a117a8b PKCS#7: Make the signature a pointer rather than embedding it
Point to the public_key_signature struct from the pkcs7_signed_info struct
rather than embedding it.  This makes the code consistent with the X.509
signature handling and makes it possible to have a common cleanup function.

We also save a copy of the digest in the signature without sharing the
memory with the crypto layer metadata.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
David Howells 77d0910d15 X.509: Retain the key verification data
Retain the key verification data (ie. the struct public_key_signature)
including the digest and the key identifiers.

Note that this means that we need to take a separate copy of the digest in
x509_get_sig_params() rather than lumping it in with the crypto layer data.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
David Howells a022ec0269 KEYS: Add identifier pointers to public_key_signature struct
Add key identifier pointers to public_key_signature struct so that they can
be used to retain the identifier of the key to be used to verify the
signature in both PKCS#7 and X.509.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
David Howells 3b76456317 KEYS: Allow authentication data to be stored in an asymmetric key
Allow authentication data to be stored in an asymmetric key in the 4th
element of the key payload and provide a way for it to be destroyed.

For the public key subtype, this will be a public_key_signature struct.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
David Howells 864e7a816a X.509: Whitespace cleanup
Clean up some whitespace.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-04-06 16:13:33 +01:00
Colin Ian King 06af9b0f49 PKCS#7: fix missing break on OID_sha224 case
The OID_sha224 case is missing a break and it falls through
to the -ENOPKG error default.  Since HASH_ALGO_SHA224 seems
to be supported, this looks like an unintentional missing break.

Fixes: 07f081fb50 ("PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them")
Cc: <stable@vger.kernel.org> # 4.2+
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-04-05 20:35:44 +08:00
Linus Torvalds 62f444e054 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This fixes a bug in pkcs7_validate_trust and its users where the
  output value may in fact be taken from uninitialised memory"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  PKCS#7: pkcs7_validate_trust(): initialize the _trusted output argument
2016-03-30 13:28:34 -05:00
Nicolai Stange e54358915d PKCS#7: pkcs7_validate_trust(): initialize the _trusted output argument
Despite what the DocBook comment to pkcs7_validate_trust() says, the
*_trusted argument is never set to false.

pkcs7_validate_trust() only positively sets *_trusted upon encountering
a trusted PKCS#7 SignedInfo block.

This is quite unfortunate since its callers, system_verify_data() for
example, depend on pkcs7_validate_trust() clearing *_trusted on non-trust.

Indeed, UBSAN splats when attempting to load the uninitialized local
variable 'trusted' from system_verify_data() in pkcs7_validate_trust():

  UBSAN: Undefined behaviour in crypto/asymmetric_keys/pkcs7_trust.c:194:14
  load of value 82 is not a valid value for type '_Bool'
  [...]
  Call Trace:
    [<ffffffff818c4d35>] dump_stack+0xbc/0x117
    [<ffffffff818c4c79>] ? _atomic_dec_and_lock+0x169/0x169
    [<ffffffff8194113b>] ubsan_epilogue+0xd/0x4e
    [<ffffffff819419fa>] __ubsan_handle_load_invalid_value+0x111/0x158
    [<ffffffff819418e9>] ? val_to_string.constprop.12+0xcf/0xcf
    [<ffffffff818334a4>] ? x509_request_asymmetric_key+0x114/0x370
    [<ffffffff814b83f0>] ? kfree+0x220/0x370
    [<ffffffff818312c2>] ? public_key_verify_signature_2+0x32/0x50
    [<ffffffff81835e04>] pkcs7_validate_trust+0x524/0x5f0
    [<ffffffff813c391a>] system_verify_data+0xca/0x170
    [<ffffffff813c3850>] ? top_trace_array+0x9b/0x9b
    [<ffffffff81510b29>] ? __vfs_read+0x279/0x3d0
    [<ffffffff8129372f>] mod_verify_sig+0x1ff/0x290
    [...]

The implication is that pkcs7_validate_trust() effectively grants trust
when it really shouldn't have.

Fix this by explicitly setting *_trusted to false at the very beginning
of pkcs7_validate_trust().

Cc: <stable@vger.kernel.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-23 20:57:24 +08:00
David Howells 4e8ae72a75 X.509: Make algo identifiers text instead of enum
Make the identifier public key and digest algorithm fields text instead of
enum.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
David Howells d43de6c780 akcipher: Move the RSA DER encoding check to the crypto layer
Move the RSA EMSA-PKCS1-v1_5 encoding from the asymmetric-key public_key
subtype to the rsa crypto module's pkcs1pad template.  This means that the
public_key subtype no longer has any dependencies on public key type.

To make this work, the following changes have been made:

 (1) The rsa pkcs1pad template is now used for RSA keys.  This strips off the
     padding and returns just the message hash.

 (2) In a previous patch, the pkcs1pad template gained an optional second
     parameter that, if given, specifies the hash used.  We now give this,
     and pkcs1pad checks the encoded message E(M) for the EMSA-PKCS1-v1_5
     encoding and verifies that the correct digest OID is present.

 (3) The crypto driver in crypto/asymmetric_keys/rsa.c is now reduced to
     something that doesn't care about what the encryption actually does
     and and has been merged into public_key.c.

 (4) CONFIG_PUBLIC_KEY_ALGO_RSA is gone.  Module signing must set
     CONFIG_CRYPTO_RSA=y instead.

Thoughts:

 (*) Should the encoding style (eg. raw, EMSA-PKCS1-v1_5) also be passed to
     the padding template?  Should there be multiple padding templates
     registered that share most of the code?

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-03-03 21:49:27 +00:00
David Howells 7650cb80e4 X.509: Handle midnight alternative notation in GeneralizedTime
The ASN.1 GeneralizedTime object carries an ISO 8601 format date and time.
The time is permitted to show midnight as 00:00 or 24:00 (the latter being
equivalent of 00:00 of the following day).

The permitted value is checked in x509_decode_time() but the actual
handling is left to mktime64().

Without this patch, certain X.509 certificates will be rejected and could
lead to an unbootable kernel.

Note that with this patch we also permit any 24:mm:ss time and extend this
to UTCTime, which whilst not strictly correct don't permit much leeway in
fiddling date strings.

Reported-by: Rudolf Polzer <rpolzer@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
cc: David Woodhouse <David.Woodhouse@intel.com>
cc: John Stultz <john.stultz@linaro.org>
2016-02-29 14:29:40 +00:00
David Howells da02559c9f X.509: Support leap seconds
The format of ASN.1 GeneralizedTime seems to be specified by ISO 8601
[X.680 46.3] and this apparently supports leap seconds (ie. the seconds
field is 60).  It's not entirely clear that ASN.1 expects it, but we can
relax the seconds check slightly for GeneralizedTime.

This results in us passing a time with sec as 60 to mktime64(), which
handles it as being a duplicate of the 0th second of the next minute.

We can't really do otherwise without giving the kernel much greater
knowledge of where all the leap seconds are.  Unfortunately, this would
require change the mapping of the kernel's current-time-in-seconds.

UTCTime, however, only supports a seconds value in the range 00-59, but for
the sake of simplicity allow this with UTCTime also.

Without this patch, certain X.509 certificates will be rejected,
potentially making a kernel unbootable.

Reported-by: Rudolf Polzer <rpolzer@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
cc: David Woodhouse <David.Woodhouse@intel.com>
cc: John Stultz <john.stultz@linaro.org>
2016-02-29 14:29:40 +00:00
David Howells ac4cbedfdf X.509: Fix leap year handling again
There are still a couple of minor issues in the X.509 leap year handling:

 (1) To avoid doing a modulus-by-400 in addition to a modulus-by-100 when
     determining whether the year is a leap year or not, I divided the year
     by 100 after doing the modulus-by-100, thereby letting the compiler do
     one instruction for both, and then did a modulus-by-4.

     Unfortunately, I then passed the now-modified year value to mktime64()
     to construct a time value.

     Since this isn't a fast path and since mktime64() does a bunch of
     divisions, just condense down to "% 400".  It's also easier to read.

 (2) The default month length for any February where the year doesn't
     divide by four exactly is obtained from the month_length[] array where
     the value is 29, not 28.

     This is fixed by altering the table.

Reported-by: Rudolf Polzer <rpolzer@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
cc: stable@vger.kernel.org
2016-02-29 14:29:40 +00:00
Colin Ian King 06aae59242 PKCS#7: fix unitialized boolean 'want'
The boolean want is not initialized and hence garbage. The default should
be false (later it is only set to true on tne sinfo->authattrs check).

Found with static analysis using CoverityScan

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-02-29 14:29:03 +00:00
Tadeusz Struk db6c43bd21 crypto: KEYS: convert public key and digsig asym to the akcipher api
This patch converts the module verification code to the new akcipher API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David Howells <dhowells@redhat.com>
2016-02-10 10:13:27 +00:00
Herbert Xu f75516a815 crypto: keys - Revert "convert public key to akcipher api"
This needs to go through the security tree so I'm reverting the
patches for now.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-09 16:18:01 +08:00
Tadeusz Struk 57f96bbab9 crypto: asymmetric_keys - convert public key and digsig asym to the akcipher api
This patch converts the module verification code to the new akcipher API.

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-02-06 15:33:25 +08:00
Peter Jones 7ee7014d0e PKCS#7: Don't require SpcSpOpusInfo in Authenticode pkcs7 signatures
Dave Young reported:
> Hi,
>
> I saw the warning "Missing required AuthAttr" when testing kexec,
> known issue?  Idea about how to fix it?
>
> The kernel is latest linus tree plus sevral patches from Toshi to
> cleanup io resource structure.
>
> in function pkcs7_sig_note_set_of_authattrs():
>         if (!test_bit(sinfo_has_content_type, &sinfo->aa_set) ||
>             !test_bit(sinfo_has_message_digest, &sinfo->aa_set) ||
>             (ctx->msg->data_type == OID_msIndirectData &&
>              !test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))) {
>                 pr_warn("Missing required AuthAttr\n");
>                 return -EBADMSG;
>         }
>
> The third condition below is true:
> (ctx->msg->data_type == OID_msIndirectData &&
>              !test_bit(sinfo_has_ms_opus_info, &sinfo->aa_set))
>
> I signed the kernel with redhat test key like below:
> pesign -c 'Red Hat Test Certificate' -i arch/x86/boot/bzImage -o /boot/vmlinuz-4.4.0-rc8+ -s --force

And right he is!  The Authenticode specification is a paragon amongst
technical documents, and has this pearl of wisdom to offer:

---------------------------------
Authenticode-Specific SignerInfo UnauthenticatedAttributes Structures

  The following Authenticode-specific data structures are present in
  SignerInfo authenticated attributes.

  SpcSpOpusInfo
  SpcSpOpusInfo is identified by SPC_SP_OPUS_INFO_OBJID
  (1.3.6.1.4.1.311.2.1.12) and is defined as follows:
  SpcSpOpusInfo ::= SEQUENCE {
    programName  [0] EXPLICIT SpcString OPTIONAL,
    moreInfo     [1] EXPLICIT SpcLink OPTIONAL,
  } --#public--

  SpcSpOpusInfo has two fields:
    programName
      This field contains the program description:
      If publisher chooses not to specify a description, the SpcString
      structure contains a zero-length program name.
      If the publisher chooses to specify a
      description, the SpcString structure contains a Unicode string.
    moreInfo
      This field is set to an SPCLink structure that contains a URL for
      a Web site with more information about the signer. The URL is an
      ASCII string.
---------------------------------

Which is to say that this is an optional *unauthenticated* field which
may be present in the Authenticated Attribute list.  This is not how
pkcs7 is supposed to work, so when David implemented this, he didn't
appreciate the subtlety the original spec author was working with, and
missed the part of the sublime prose that says this Authenticated
Attribute is an Unauthenticated Attribute.  As a result, the code in
question simply takes as given that the Authenticated Attributes should
be authenticated.

But this one should not, individually.  Because it says it's not
authenticated.

It still has to hash right so the TBS digest is correct.  So it is both
authenticated and unauthenticated, all at once.  Truly, a wonder of
technical accomplishment.

Additionally, pesign's implementation has always attempted to be
compatible with the signatures emitted from contemporary versions of
Microsoft's signtool.exe.  During the initial implementation, Microsoft
signatures always produced the same values for SpcSpOpusInfo -
{U"Microsoft Windows", "http://www.microsoft.com"} - without regard to
who the signer was.

Sometime between Windows 8 and Windows 8.1 they stopped including the
field in their signatures altogether, and as such pesign stopped
producing them in commits c0c4da6 and d79cb0c, sometime around June of
2012.  The theory here is that anything that breaks with
pesign signatures would also be breaking with signtool.exe sigs as well,
and that'll be a more noticed problem for firmwares parsing it, so it'll
get fixed.  The fact that we've done exactly this bug in Linux code is
first class, grade A irony.

So anyway, we should not be checking this field for presence or any
particular value: if the field exists, it should be at the right place,
but aside from that, as long as the hash matches the field is good.

Signed-off-by: Peter Jones <pjones@redhat.com>
Tested-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-01-25 21:47:45 +08:00
Linus Torvalds 5807fcaa9b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:

 - EVM gains support for loading an x509 cert from the kernel
   (EVM_LOAD_X509), into the EVM trusted kernel keyring.

 - Smack implements 'file receive' process-based permission checking for
   sockets, rather than just depending on inode checks.

 - Misc enhancments for TPM & TPM2.

 - Cleanups and bugfixes for SELinux, Keys, and IMA.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits)
  selinux: Inode label revalidation performance fix
  KEYS: refcount bug fix
  ima: ima_write_policy() limit locking
  IMA: policy can be updated zero times
  selinux: rate-limit netlink message warnings in selinux_nlmsg_perm()
  selinux: export validatetrans decisions
  gfs2: Invalid security labels of inodes when they go invalid
  selinux: Revalidate invalid inode security labels
  security: Add hook to invalidate inode security labels
  selinux: Add accessor functions for inode->i_security
  security: Make inode argument of inode_getsecid non-const
  security: Make inode argument of inode_getsecurity non-const
  selinux: Remove unused variable in selinux_inode_init_security
  keys, trusted: seal with a TPM2 authorization policy
  keys, trusted: select hash algorithm for TPM2 chips
  keys, trusted: fix: *do not* allow duplicate key options
  tpm_ibmvtpm: properly handle interrupted packet receptions
  tpm_tis: Tighten IRQ auto-probing
  tpm_tis: Refactor the interrupt setup
  tpm_tis: Get rid of the duplicate IRQ probing code
  ...
2016-01-17 19:13:15 -08:00