A PKCS#7 or CMS message can have per-signature authenticated attributes
that are digested as a lump and signed by the authorising key for that
signature. If such attributes exist, the content digest isn't itself
signed, but rather it is included in a special authattr which then
contributes to the signature.
Further, we already require the master message content type to be
pkcs7_signedData - but there's also a separate content type for the data
itself within the SignedData object and this must be repeated inside the
authattrs for each signer [RFC2315 9.2, RFC5652 11.1].
We should really validate the authattrs if they exist or forbid them
entirely as appropriate. To this end:
(1) Alter the PKCS#7 parser to reject any message that has more than one
signature where at least one signature has authattrs and at least one
that does not.
(2) Validate authattrs if they are present and strongly restrict them.
Only the following authattrs are permitted and all others are
rejected:
(a) contentType. This is checked to be an OID that matches the
content type in the SignedData object.
(b) messageDigest. This must match the crypto digest of the data.
(c) signingTime. If present, we check that this is a valid, parseable
UTCTime or GeneralTime and that the date it encodes fits within
the validity window of the matching X.509 cert.
(d) S/MIME capabilities. We don't check the contents.
(e) Authenticode SP Opus Info. We don't check the contents.
(f) Authenticode Statement Type. We don't check the contents.
The message is rejected if (a) or (b) are missing. If the message is
an Authenticode type, the message is rejected if (e) is missing; if
not Authenticode, the message is rejected if (d) - (f) are present.
The S/MIME capabilities authattr (d) unfortunately has to be allowed
to support kernels already signed by the pesign program. This only
affects kexec. sign-file suppresses them (CMS_NOSMIMECAP).
The message is also rejected if an authattr is given more than once or
if it contains more than one element in its set of values.
(3) Add a parameter to pkcs7_verify() to select one of the following
restrictions and pass in the appropriate option from the callers:
(*) VERIFYING_MODULE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
forbids authattrs. sign-file sets CMS_NOATTR. We could be more
flexible and permit authattrs optionally, but only permit minimal
content.
(*) VERIFYING_FIRMWARE_SIGNATURE
This requires that the SignedData content type be pkcs7-data and
requires authattrs. In future, this will require an attribute
holding the target firmware name in addition to the minimal set.
(*) VERIFYING_UNSPECIFIED_SIGNATURE
This requires that the SignedData content type be pkcs7-data but
allows either no authattrs or only permits the minimal set.
(*) VERIFYING_KEXEC_PE_SIGNATURE
This only supports the Authenticode SPC_INDIRECT_DATA content type
and requires at least an SpcSpOpusInfo authattr in addition to the
minimal set. It also permits an SPC_STATEMENT_TYPE authattr (and
an S/MIME capabilities authattr because the pesign program doesn't
remove these).
(*) VERIFYING_KEY_SIGNATURE
(*) VERIFYING_KEY_SELF_SIGNATURE
These are invalid in this context but are included for later use
when limiting the use of X.509 certs.
(4) The pkcs7_test key type is given a module parameter to select between
the above options for testing purposes. For example:
echo 1 >/sys/module/pkcs7_test_key/parameters/usage
keyctl padd pkcs7_test foo @s </tmp/stuff.pkcs7
will attempt to check the signature on stuff.pkcs7 as if it contains a
firmware blob (1 being VERIFYING_FIRMWARE_SIGNATURE).
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
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>
Since CMS is an evolution of PKCS#7, with much of the ASN.1 being
compatible, add support for CMS signed-data messages also [RFC5652 sec 5].
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-By: David Woodhouse <David.Woodhouse@intel.com>
The key identifiers fabricated from an X.509 certificate are currently:
(A) Concatenation of serial number and issuer
(B) Concatenation of subject and subjectKeyID (SKID)
When verifying one X.509 certificate with another, the AKID in the target
can be used to match the authoritative certificate. The AKID can specify
the match in one or both of two ways:
(1) Compare authorityCertSerialNumber and authorityCertIssuer from the AKID
to identifier (A) above.
(2) Compare keyIdentifier from the AKID plus the issuer from the target
certificate to identifier (B) above.
When verifying a PKCS#7 message, the only available comparison is between
the IssuerAndSerialNumber field and identifier (A) above.
However, a subsequent patch adds CMS support. Whilst CMS still supports a
match on IssuerAndSerialNumber as for PKCS#7, it also supports an
alternative - which is the SubjectKeyIdentifier field. This is used to
match to an X.509 certificate on the SKID alone. No subject information is
available to be used.
To this end change the fabrication of (B) above to be from the X.509 SKID
alone. The AKID in keyIdentifier form then only matches on that and does
not include the issuer.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-By: David Woodhouse <David.Woodhouse@intel.com>
We only support PKCS#7 signed-data [RFC2315 sec 9] content at the top level,
so reject anything else. Further, check that the version numbers in
SignedData and SignerInfo are 1 in both cases.
Note that we don't restrict the inner content type. In the PKCS#7 code we
don't parse the data attached there, but merely verify the signature over
it.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-By: David Woodhouse <David.Woodhouse@intel.com>
It is possible for a PKCS#7 message to have detached data. However, to verify
the signatures on a PKCS#7 message, we have to be able to digest the data.
Provide a function to supply that data. An error is given if the PKCS#7
message included embedded data.
This is used in a subsequent patch to supply the data to module signing where
the signature is in the form of a PKCS#7 message with detached data, whereby
the detached data is the module content that is signed.
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
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>
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>
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Merge tag 'module-implicit-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux
Pull implicit module.h fixes from Paul Gortmaker:
"Fix up implicit <module.h> users that will break later.
The files changed here are simply modular source files that are
implicitly relying on <module.h> being present. We fix them up now,
so that we can decouple some of the module related init code from the
core init code in the future.
The addition of the module.h include to several files here is also a
no-op from a code generation point of view, else there would already
be compile issues with these files today.
There may be lots more implicit includes of <module.h> in tree, but
these are the ones that extensive build test coverage has shown that
must be fixed in order to avoid build breakage fallout for the pending
module.h <---> init.h code relocation we desire to complete"
* tag 'module-implicit-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
frv: add module.h to mb93090-mb00/flash.c to avoid compile fail
drivers/cpufreq: include <module.h> for modular exynos-cpufreq.c code
drivers/staging: include <module.h> for modular android tegra_ion code
crypto/asymmetric_keys: pkcs7_key_type needs module.h
sh: mach-highlander/psw.c is tristate and should use module.h
drivers/regulator: include <module.h> for modular max77802 code
drivers/pcmcia: include <module.h> for modular xxs1500_ss code
drivers/hsi: include <module.h> for modular omap_ssi code
drivers/gpu: include <module.h> for modular rockchip code
drivers/gpio: include <module.h> for modular crystalcove code
drivers/clk: include <module.h> for clk-max77xxx modular code
Pull security subsystem updates from James Morris:
"The main change in this kernel is Casey's generalized LSM stacking
work, which removes the hard-coding of Capabilities and Yama stacking,
allowing multiple arbitrary "small" LSMs to be stacked with a default
monolithic module (e.g. SELinux, Smack, AppArmor).
See
https://lwn.net/Articles/636056/
This will allow smaller, simpler LSMs to be incorporated into the
mainline kernel and arbitrarily stacked by users. Also, this is a
useful cleanup of the LSM code in its own right"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (38 commits)
tpm, tpm_crb: fix le64_to_cpu conversions in crb_acpi_add()
vTPM: set virtual device before passing to ibmvtpm_reset_crq
tpm_ibmvtpm: remove unneccessary message level.
ima: update builtin policies
ima: extend "mask" policy matching support
ima: add support for new "euid" policy condition
ima: fix ima_show_template_data_ascii()
Smack: freeing an error pointer in smk_write_revoke_subj()
selinux: fix setting of security labels on NFS
selinux: Remove unused permission definitions
selinux: enable genfscon labeling for sysfs and pstore files
selinux: enable per-file labeling for debugfs files.
selinux: update netlink socket classes
signals: don't abuse __flush_signals() in selinux_bprm_committed_creds()
selinux: Print 'sclass' as string when unrecognized netlink message occurs
Smack: allow multiple labels in onlycap
Smack: fix seq operations in smackfs
ima: pass iint to ima_add_violation()
ima: wrap event related data to the new ima_event_data structure
integrity: add validity checks for 'path' parameter
...
arm64:allmodconfig fails to build as follows.
In file included from include/acpi/platform/aclinux.h:74:0,
from include/acpi/platform/acenv.h:173,
from include/acpi/acpi.h:56,
from include/linux/acpi.h:37,
from ./arch/arm64/include/asm/dma-mapping.h:21,
from include/linux/dma-mapping.h:86,
from include/linux/skbuff.h:34,
from include/crypto/algapi.h:18,
from crypto/asymmetric_keys/rsa.c:16:
include/linux/ctype.h:15:12: error: expected ‘;’, ‘,’ or ‘)’
before numeric constant
#define _X 0x40 /* hex digit */
^
crypto/asymmetric_keys/rsa.c:123:47: note: in expansion of macro ‘_X’
static int RSA_I2OSP(MPI x, size_t xLen, u8 **_X)
^
crypto/asymmetric_keys/rsa.c: In function ‘RSA_verify_signature’:
crypto/asymmetric_keys/rsa.c:256:2: error:
implicit declaration of function ‘RSA_I2OSP’
The problem is caused by an unrelated include file change, resulting in
the inclusion of ctype.h on arm64. This in turn causes the local variable
_X to conflict with macro _X used in ctype.h.
Fixes: b6197b93fa ("arm64 : Introduce support for ACPI _CCA object")
Cc: Suthikulpanit, Suravee <Suravee.Suthikulpanit@amd.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This driver builds off of the tristate CONFIG_PKCS7_TEST_KEY and calls
module_init and module_exit. So it should explicitly include module.h
to avoid compile breakage during header shuffles done in the future.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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
Pull security subsystem updates from James Morris.
Mostly ima, selinux, smack and key handling updates.
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (65 commits)
integrity: do zero padding of the key id
KEYS: output last portion of fingerprint in /proc/keys
KEYS: strip 'id:' from ca_keyid
KEYS: use swapped SKID for performing partial matching
KEYS: Restore partial ID matching functionality for asymmetric keys
X.509: If available, use the raw subjKeyId to form the key description
KEYS: handle error code encoded in pointer
selinux: normalize audit log formatting
selinux: cleanup error reporting in selinux_nlmsg_perm()
KEYS: Check hex2bin()'s return when generating an asymmetric key ID
ima: detect violations for mmaped files
ima: fix race condition on ima_rdwr_violation_check and process_measurement
ima: added ima_policy_flag variable
ima: return an error code from ima_add_boot_aggregate()
ima: provide 'ima_appraise=log' kernel option
ima: move keyring initialization to ima_init()
PKCS#7: Handle PKCS#7 messages that contain no X.509 certs
PKCS#7: Better handling of unsupported crypto
KEYS: Overhaul key identification when searching for asymmetric keys
KEYS: Implement binary asymmetric key ID handling
...
Previous version of KEYS used to output last 4 bytes of fingerprint.
Now it outputs 8 last bytes of raw subject, which does not make any
visual meaning at all. This patch restores old behavior.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
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>
Earlier KEYS code used pure subject key identifiers (fingerprint)
for searching keys. Latest merged code removed that and broke
compatibility with integrity subsytem signatures and original
format of module signatures.
This patch returns back partial matching on SKID.
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>
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>
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>
As it stands, the code to generate an asymmetric key ID prechecks the hex
string it is given whilst determining the length, before it allocates the
buffer for hex2bin() to translate into - which mean that checking the result of
hex2bin() is redundant.
Unfortunately, hex2bin() is marked as __must_check, which means that the
following warning may be generated if the return value isn't checked:
crypto/asymmetric_keys/asymmetric_type.c: In function
asymmetric_key_hex_to_key_id:
crypto/asymmetric_keys/asymmetric_type.c:110: warning: ignoring return
value of hex2bin, declared with attribute warn_unused_result
The warning can't be avoided by casting the result to void.
Instead, use strlen() to check the length of the string and ignore the fact
that the string might not be entirely valid hex until after the allocation has
been done - in which case we can use the result of hex2bin() for this.
Signed-off-by: David Howells <dhowells@redhat.com>
The X.509 certificate list in a PKCS#7 message is optional. To save space, we
can omit the inclusion of any X.509 certificates if we are sure that we can
look the relevant public key up by the serial number and issuer given in a
signed info block.
This also supports use of a signed info block for which we can't find a
matching X.509 cert in the certificate list, though it be populated.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
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>
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>
Implement the first step in using binary key IDs for asymmetric keys rather
than hex string keys.
The previously added match data preparsing will be able to convert hex
criterion strings into binary which can then be compared more rapidly.
Further, we actually want more then one ID string per public key. The problem
is that X.509 certs refer to other X.509 certs by matching Issuer + AuthKeyId
to Subject + SubjKeyId, but PKCS#7 messages match against X.509 Issuer +
SerialNumber.
This patch just provides facilities for a later patch to make use of.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Make the key matching functions pointed to by key_match_data::cmp return bool
rather than int.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
A previous patch added a ->match_preparse() method to the key type. This is
allowed to override the function called by the iteration algorithm.
Therefore, we can just set a default that simply checks for an exact match of
the key description with the original criterion data and allow match_preparse
to override it as needed.
The key_type::match op is then redundant and can be removed, as can the
user_match() function.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Remove key_type::def_lookup_type as it's no longer used. The information now
defaults to KEYRING_SEARCH_LOOKUP_DIRECT but may be overridden by
type->match_preparse().
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Preparse the match data. This provides several advantages:
(1) The preparser can reject invalid criteria up front.
(2) The preparser can convert the criteria to binary data if necessary (the
asymmetric key type really wants to do binary comparison of the key IDs).
(3) The preparser can set the type of search to be performed. This means
that it's not then a one-off setting in the key type.
(4) The preparser can set an appropriate comparator function.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
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Merge tag 'keys-fixes-20140916' into keys-next
Merge in keyrings fixes, at least some of which later patches depend on:
(1) Reinstate the production of EPERM for key types beginning with '.' in
requests from userspace.
(2) Tidy up the cleanup of PKCS#7 message signed information blocks and fix a
bug this made more obvious.
Signed-off-by: David Howells <dhowells@redhat.coM>
Fix the parser cleanup code to drain parsed out X.509 certs in the case that
the decode fails and we jump to error_decode.
The function is rearranged so that the same cleanup code is used in the success
case as the error case - just that the message descriptor under construction is
only released if it is still pointed to by the context struct at that point.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
The code to free a signed info block is repeated several times, so move the
code to do it into a function of its own. This gives us a place to add clean
ups for stuff that gets added to pkcs7_signed_info.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Printing in base signature handling should have a prefix, so set pr_fmt().
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Relax the check on the length of the PKCS#7 cert as it appears that the PE
file wrapper size gets rounded up to the nearest 8.
The debugging output looks like this:
PEFILE: ==> verify_pefile_signature()
PEFILE: ==> pefile_parse_binary()
PEFILE: checksum @ 110
PEFILE: header size = 200
PEFILE: cert = 968 @547be0 [68 09 00 00 00 02 02 00 30 82 09 56 ]
PEFILE: sig wrapper = { 968, 200, 2 }
PEFILE: Signature data not PKCS#7
The wrapper is the first 8 bytes of the hex dump inside []. This indicates a
length of 0x968 bytes, including the wrapper header - so 0x960 bytes of
payload.
The ASN.1 wrapper begins [ ... 30 82 09 56 ]. That indicates an object of size
0x956 - a four byte discrepency, presumably just padding for alignment
purposes.
So we just check that the ASN.1 container is no bigger than the payload and
reduce the recorded size appropriately.
Whilst we're at it, allow shorter PKCS#7 objects that manage to squeeze within
127 or 255 bytes. It's just about conceivable if no X.509 certs are included
in the PKCS#7 message.
Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Peter Jones <pjones@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
The length of the name of an asymmetric key subtype must be stored in struct
asymmetric_key_subtype::name_len so that it can be matched by a search for
"<subkey_name>:<partial_fingerprint>". Fix the public_key subtype to have
name_len set.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
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>
X.509 certificate issuer and subject fields are mandatory fields in the ASN.1
and so their existence needn't be tested for. They are guaranteed to end up
with an empty string if the name material has nothing we can use (see
x509_fabricate_name()).
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
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>
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>
Fixes the following sparse warnings:
crypto/asymmetric_keys/pkcs7_key_type.c:73:17: warning:
symbol 'key_type_pkcs7' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David Howells <dhowells@redhat.com>
crypto/asymmetric_keys/pkcs7_key_type.c needs to #include linux/err.h rather
than relying on getting it through other headers.
Without this, the powerpc allyesconfig build fails.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David Howells <dhowells@redhat.com>
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Merge tag 'keys-pefile-20140709' into keys-next
Here's a set of changes that implement a PE file signature checker.
This provides the following facility:
(1) Extract the signature from the PE file. This is a PKCS#7 message
containing, as its data, a hash of the signed parts of the file.
(2) Digest the signed parts of the file.
(3) Compare the digest with the one from the PKCS#7 message.
(4) Validate the signatures on the PKCS#7 message and indicate
whether it was matched by a trusted key.
Signed-off-by: David Howells <dhowells@redhat.com>
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Merge tag 'keys-pkcs7-20140708' into keys-next
Here's a set of changes that implement a PKCS#7 message parser in the kernel.
The PKCS#7 message parsing will then be used to limit kexec to authenticated
kernels only if so configured.
The changes provide the following facilities:
(1) Parse an ASN.1 PKCS#7 message and pick out useful bits such as the data
content and the X.509 certificates used to sign it and all the data
signatures.
(2) Verify all the data signatures against the set of X.509 certificates
available in the message.
(3) Follow the certificate chains and verify that:
(a) for every self-signed X.509 certificate, check that it validly signed
itself, and:
(b) for every non-self-signed certificate, if we have a 'parent'
certificate, the former is validly signed by the latter.
(4) Look for intersections between the certificate chains and the trusted
keyring, if any intersections are found, verify that the trusted
certificates signed the intersection point in the chain.
(5) For testing purposes, a key type can be made available that will take a
PKCS#7 message, check that the message is trustworthy, and if so, add its
data content into the key.
Note that (5) has to be altered to take account of the preparsing patches
already committed to this branch.
Signed-off-by: David Howells <dhowells@redhat.com>
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>
Provide a generic instantiation function for key types that use the preparse
hook. This makes it easier to prereserve key quota before keyrings get locked
to retain the new 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>
You can select MPILIB_EXTRA all you want, it doesn't exist ;-)
Surprised kconfig doesn't complain about that...
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
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>
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>
To avoid code duplication this patch refactors asymmetric_key_match(),
making partial ID string match a separate function.
This patch also implicitly fixes a bug in the code. asymmetric_key_match()
allows to match the key by its subtype. But subtype matching could be
undone if asymmetric_key_id(key) would return NULL. This patch first
checks for matching spec and then for its value.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
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>
Validate the PKCS#7 trust chain against the contents of the system keyring.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Digest the signed parts of the PE binary, canonicalising the section table
before we need it, and then compare the the resulting digest to the one in the
PKCS#7 signed content.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
The pesign utility had a bug where it was using OID_msIndividualSPKeyPurpose
instead of OID_msPeImageDataObjId - so allow both OIDs.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
The PKCS#7 certificate should contain a "Microsoft individual code signing"
data blob as its signed content. This blob contains a digest of the signed
content of the PE binary and the OID of the digest algorithm used (typically
SHA256).
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Parse the content of the certificate blob, presuming it to be PKCS#7 format.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
The certificate data block in a PE binary has a wrapper around the PKCS#7
signature we actually want to get at. Strip this off and check that we've got
something that appears to be a PKCS#7 signature.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Parse a PE binary to find a key and a signature contained therein. Later
patches will check the signature and add the key if the signature checks out.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Find the intersection between the X.509 certificate chain contained in a PKCS#7
message and a set of keys that we already know and trust.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Verify certificate chain in the X.509 certificates contained within the PKCS#7
message as far as possible. If any signature that we should be able to verify
fails, we reject the whole lot.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Find the appropriate key in the PKCS#7 key list and verify the signature with
it. There may be several keys in there forming a chain. Any link in that
chain or the root of that chain may be in our keyrings.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Digest the data in a PKCS#7 signed-data message and attach to the
public_key_signature struct contained in the pkcs7_message struct.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Implement a parser for a PKCS#7 signed-data message as described in part of
RFC 2315.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
PKCS#7 validation requires access to the serial number and the raw names in an
X.509 certificate.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Josh Boyer <jwboyer@redhat.com>
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>
Pull crypto update from Herbert Xu:
- Made x86 ablk_helper generic for ARM
- Phase out chainiv in favour of eseqiv (affects IPsec)
- Fixed aes-cbc IV corruption on s390
- Added constant-time crypto_memneq which replaces memcmp
- Fixed aes-ctr in omap-aes
- Added OMAP3 ROM RNG support
- Add PRNG support for MSM SoC's
- Add and use Job Ring API in caam
- Misc fixes
[ NOTE! This pull request was sent within the merge window, but Herbert
has some questionable email sending setup that makes him public enemy
#1 as far as gmail is concerned. So most of his emails seem to be
trapped by gmail as spam, resulting in me not seeing them. - Linus ]
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (49 commits)
crypto: s390 - Fix aes-cbc IV corruption
crypto: omap-aes - Fix CTR mode counter length
crypto: omap-sham - Add missing modalias
padata: make the sequence counter an atomic_t
crypto: caam - Modify the interface layers to use JR API's
crypto: caam - Add API's to allocate/free Job Rings
crypto: caam - Add Platform driver for Job Ring
hwrng: msm - Add PRNG support for MSM SoC's
ARM: DT: msm: Add Qualcomm's PRNG driver binding document
crypto: skcipher - Use eseqiv even on UP machines
crypto: talitos - Simplify key parsing
crypto: picoxcell - Simplify and harden key parsing
crypto: ixp4xx - Simplify and harden key parsing
crypto: authencesn - Simplify key parsing
crypto: authenc - Export key parsing helper function
crypto: mv_cesa: remove deprecated IRQF_DISABLED
hwrng: OMAP3 ROM Random Number Generator support
crypto: sha256_ssse3 - also test for BMI2
crypto: mv_cesa - Remove redundant of_match_ptr
crypto: sahara - Remove redundant of_match_ptr
...
The RSA public key algorithm needs to select MPILIB directly in Kconfig as the
'select' directive is not recursive and is thus MPILIB is not enabled by
selecting MPILIB_EXTRA.
Without this, the following errors can occur:
crypto/built-in.o: In function `RSA_verify_signature':
rsa.c:(.text+0x1d347): undefined reference to `mpi_get_nbits'
rsa.c:(.text+0x1d354): undefined reference to `mpi_get_nbits'
rsa.c:(.text+0x1d36e): undefined reference to `mpi_cmp_ui'
rsa.c:(.text+0x1d382): undefined reference to `mpi_cmp'
rsa.c:(.text+0x1d391): undefined reference to `mpi_alloc'
rsa.c:(.text+0x1d3b0): undefined reference to `mpi_powm'
rsa.c:(.text+0x1d3c3): undefined reference to `mpi_free'
rsa.c:(.text+0x1d3d8): undefined reference to `mpi_get_buffer'
rsa.c:(.text+0x1d4d4): undefined reference to `mpi_free'
rsa.c:(.text+0x1d503): undefined reference to `mpi_get_nbits'
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
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>
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>
When comparing MAC hashes, AEAD authentication tags, or other hash
values in the context of authentication or integrity checking, it
is important not to leak timing information to a potential attacker,
i.e. when communication happens over a network.
Bytewise memory comparisons (such as memcmp) are usually optimized so
that they return a nonzero value as soon as a mismatch is found. E.g,
on x86_64/i5 for 512 bytes this can be ~50 cyc for a full mismatch
and up to ~850 cyc for a full match (cold). This early-return behavior
can leak timing information as a side channel, allowing an attacker to
iteratively guess the correct result.
This patch adds a new method crypto_memneq ("memory not equal to each
other") to the crypto API that compares memory areas of the same length
in roughly "constant time" (cache misses could change the timing, but
since they don't reveal information about the content of the strings
being compared, they are effectively benign). Iow, best and worst case
behaviour take the same amount of time to complete (in contrast to
memcmp).
Note that crypto_memneq (unlike memcmp) can only be used to test for
equality or inequality, NOT for lexicographical order. This, however,
is not an issue for its use-cases within the crypto API.
We tried to locate all of the places in the crypto API where memcmp was
being used for authentication or integrity checking, and convert them
over to crypto_memneq.
crypto_memneq is declared noinline, placed in its own source file,
and compiled with optimizations that might increase code size disabled
("Os") because a smart compiler (or LTO) might notice that the return
value is always compared against zero/nonzero, and might then
reintroduce the same early-return optimization that we are trying to
avoid.
Using #pragma or __attribute__ optimization annotations of the code
for disabling optimization was avoided as it seems to be considered
broken or unmaintained for long time in GCC [1]. Therefore, we work
around that by specifying the compile flag for memneq.o directly in
the Makefile. We found that this seems to be most appropriate.
As we use ("Os"), this patch also provides a loop-free "fast-path" for
frequently used 16 byte digests. Similarly to kernel library string
functions, leave an option for future even further optimized architecture
specific assembler implementations.
This was a joint work of James Yonan and Daniel Borkmann. Also thanks
for feedback from Florian Weimer on this and earlier proposals [2].
[1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html
[2] https://lkml.org/lkml/2013/2/10/131
Signed-off-by: James Yonan <james@openvpn.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
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>
The keyring expansion patches introduces a new search method by which
key_search() attempts to walk directly to the key that has exactly the same
description as the requested one.
However, this causes inexact matching of asymmetric keys to fail. The
solution to this is to select iterative rather than direct search as the
default search type for asymmetric keys.
As an example, the kernel might have a key like this:
Magrathea: Glacier signing key: 6a2a0f82bad7e396665f465e4e3e1f9bd24b1226
and:
keyctl search <keyring-ID> asymmetric id:d24b1226
should find the key, despite that not being its exact description.
Signed-off-by: David Howells <dhowells@redhat.com>
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
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>
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>
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>
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>
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>
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>
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>
Per X.509 spec in 4.2.1.1 section, the structure of Authority Key
Identifier Extension is:
AuthorityKeyIdentifier ::= SEQUENCE {
keyIdentifier [0] KeyIdentifier OPTIONAL,
authorityCertIssuer [1] GeneralNames OPTIONAL,
authorityCertSerialNumber [2] CertificateSerialNumber OPTIONAL }
KeyIdentifier ::= OCTET STRING
When a certificate also provides
authorityCertIssuer and authorityCertSerialNumber then the length of
AuthorityKeyIdentifier SEQUENCE is likely to long form format.
e.g.
The example certificate demos/tunala/A-server.pem in openssl source:
X509v3 Authority Key Identifier:
keyid:49:FB:45:72:12:C4:CC:E1:45:A1:D3:08:9E:95:C4:2C:6D:55:3F:17
DirName:/C=NZ/L=Wellington/O=Really Irresponsible Authorisation Authority (RIAA)/OU=Cert-stamping/CN=Jackov al-Trades/emailAddress=none@fake.domain
serial:00
Current parsing rule of OID_authorityKeyIdentifier only take care the
short form format, it causes load certificate to modsign_keyring fail:
[ 12.061147] X.509: Extension: 47
[ 12.075121] MODSIGN: Problem loading in-kernel X.509 certificate (-74)
So, this patch add the parsing rule for support long form format against
Authority Key Identifier.
v3:
Changed the size check in "Short Form length" case, we allow v[3] smaller
then (vlen - 4) because authorityCertIssuer and authorityCertSerialNumber
are also possible attach in AuthorityKeyIdentifier sequence.
v2:
- Removed comma from author's name.
- Moved 'Short Form length' comment inside the if-body.
- Changed the type of sub to size_t.
- Use ASN1_INDEFINITE_LENGTH rather than writing 0x80 and 127.
- Moved the key_len's value assignment before alter v.
- Fixed the typo of octets.
- Add 2 to v before entering the loop for calculate the length.
- Removed the comment of check vlen.
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Chun-Yi Lee <jlee@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
Fix printk format warning in x509_cert_parser.c:
crypto/asymmetric_keys/x509_cert_parser.c: In function 'x509_note_OID':
crypto/asymmetric_keys/x509_cert_parser.c:113:3: warning: format '%zu' expects type 'size_t', but argument 2 has type 'long unsigned int'
Builds cleanly on i386 and x86_64.
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
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>
gpg can produce a signature file where length of signature is less than the
modulus size because the amount of space an MPI takes up is kept as low as
possible by discarding leading zeros. This regularly happens for several
modules during the build.
Fix it by relaxing check in RSA verification code.
Thanks to Tomas Mraz and Miloslav Trmac for help.
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Implement RSA public key cryptography [PKCS#1 / RFC3447]. At this time, only
the signature verification algorithm is supported. This uses the asymmetric
public key subtype to hold its key data.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Provide signature verification using an asymmetric-type key to indicate the
public key to be used.
The API is a single function that can be found in crypto/public_key.h:
int verify_signature(const struct key *key,
const struct public_key_signature *sig)
The first argument is the appropriate key to be used and the second argument
is the parsed signature data:
struct public_key_signature {
u8 *digest;
u16 digest_size;
enum pkey_hash_algo pkey_hash_algo : 8;
union {
MPI mpi[2];
struct {
MPI s; /* m^d mod n */
} rsa;
struct {
MPI r;
MPI s;
} dsa;
};
};
This should be filled in prior to calling the function. The hash algorithm
should already have been called and the hash finalised and the output should
be in a buffer pointed to by the 'digest' member.
Any extra data to be added to the hash by the hash format (eg. PGP) should
have been added by the caller prior to finalising the hash.
It is assumed that the signature is made up of a number of MPI values. If an
algorithm becomes available for which this is not the case, the above structure
will have to change.
It is also assumed that it will have been checked that the signature algorithm
matches the key algorithm.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a subtype for supporting asymmetric public-key encryption algorithms such
as DSA (FIPS-186) and RSA (PKCS#1 / RFC1337).
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The instantiation data passed to the asymmetric key type are expected to be
formatted in some way, and there are several possible standard ways to format
the data.
The two obvious standards are OpenPGP keys and X.509 certificates. The latter
is especially useful when dealing with UEFI, and the former might be useful
when dealing with, say, eCryptfs.
Further, it might be desirable to provide formatted blobs that indicate
hardware is to be accessed to retrieve the keys or that the keys live
unretrievably in a hardware store, but that the keys can be used by means of
the hardware.
From userspace, the keys can be loaded using the keyctl command, for example,
an X.509 binary certificate:
keyctl padd asymmetric foo @s <dhowells.pem
or a PGP key:
keyctl padd asymmetric bar @s <dhowells.pub
or a pointer into the contents of the TPM:
keyctl add asymmetric zebra "TPM:04982390582905f8" @s
Inside the kernel, pluggable parsers register themselves and then get to
examine the payload data to see if they can handle it. If they can, they get
to:
(1) Propose a name for the key, to be used it the name is "" or NULL.
(2) Specify the key subtype.
(3) Provide the data for the subtype.
The key type asks the parser to do its stuff before a key is allocated and thus
before the name is set. If successful, the parser stores the suggested data
into the key_preparsed_payload struct, which will be either used (if the key is
successfully created and instantiated or updated) or discarded.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Create a key type that can be used to represent an asymmetric key type for use
in appropriate cryptographic operations, such as encryption, decryption,
signature generation and signature verification.
The key type is "asymmetric" and can provide access to a variety of
cryptographic algorithms.
Possibly, this would be better as "public_key" - but that has the disadvantage
that "public key" is an overloaded term.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
