keys: drop shadowing dead prototype

The global variable pkcs7 does not exist.
Drop the variable declaration, but keep the struct prototype needed for
is_key_on_revocation_list().

Reported by clang:

keys: drop shadowing dead prototype

The global variable pkcs7 does not exist.
Drop the variable declaration, but keep the struct prototype needed for
is_key_on_revocation_list().

Reported by clang:

./include/keys/system_keyring.h:104:67: warning: declaration shadows a variable in the global scope [-Wshadow]
104 | static inline int is_key_on_revocation_list(struct pkcs7_message *pkcs7)
| ^
./include/keys/system_keyring.h:76:30: note: previous declaration is here
76 | extern struct pkcs7_message *pkcs7;
| ^

Fixes: 56c5812623f9 ("certs: Add EFI_CERT_X509_GUID support for dbx entries")
Signed-off-by: Christian Göttsche <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

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integrity: PowerVM support for loading third party code signing keys

On secure boot enabled PowerVM LPAR, third party code signing keys are
needed during early boot to verify signed third party modu

integrity: PowerVM support for loading third party code signing keys

On secure boot enabled PowerVM LPAR, third party code signing keys are
needed during early boot to verify signed third party modules. These
third party keys are stored in moduledb object in the Platform
KeyStore (PKS).

Load third party code signing keys onto .secondary_trusted_keys keyring.

Signed-off-by: Nayna Jain <[email protected]>
Reviewed-and-tested-by: Mimi Zohar <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Nageswara R Sastry <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

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KEYS: DigitalSignature link restriction

Add a new link restriction. Restrict the addition of keys in a keyring
based on the key having digitalSignature usage set. Additionally, verify
the new certi

KEYS: DigitalSignature link restriction

Add a new link restriction. Restrict the addition of keys in a keyring
based on the key having digitalSignature usage set. Additionally, verify
the new certificate against the ones in the system keyrings. Add two
additional functions to use the new restriction within either the builtin
or secondary keyrings.

[[email protected]: Fix checkpatch.pl --strict issues]
Signed-off-by: Eric Snowberg <[email protected]>
Reviewed-and-tested-by: Mimi Zohar <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

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certs: Factor out the blacklist hash creation

Factor out the blacklist hash creation with the get_raw_hash() helper.
This also centralize the "tbs" and "bin" prefixes and make them private,
which he

certs: Factor out the blacklist hash creation

Factor out the blacklist hash creation with the get_raw_hash() helper.
This also centralize the "tbs" and "bin" prefixes and make them private,
which help to manage them consistently.

Cc: David Howells <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: David Woodhouse <[email protected]>
Cc: Eric Snowberg <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Signed-off-by: Mickaël Salaün <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jarkko Sakkinen <[email protected]>

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KEYS: Introduce link restriction for machine keys

Introduce a new link restriction that includes the trusted builtin,
secondary and machine keys. The restriction is based on the key to be
added bein

KEYS: Introduce link restriction for machine keys

Introduce a new link restriction that includes the trusted builtin,
secondary and machine keys. The restriction is based on the key to be
added being vouched for by a key in any of these three keyrings.

With the introduction of the machine keyring, the end-user may choose to
trust Machine Owner Keys (MOK) within the kernel. If they have chosen to
trust them, the .machine keyring will contain these keys. If not, the
machine keyring will always be empty. Update the restriction check to
allow the secondary trusted keyring to also trust machine keys.

Allow the .machine keyring to be linked to the secondary_trusted_keys.
After the link is created, keys contained in the .machine keyring will
automatically be searched when searching secondary_trusted_keys.

Suggested-by: Mimi Zohar <[email protected]>
Signed-off-by: Eric Snowberg <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Mimi Zohar <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

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KEYS: store reference to machine keyring

Expose the .machine keyring created in integrity code by adding
a reference. Store a reference to the machine keyring in
system keyring code. The system key

KEYS: store reference to machine keyring

Expose the .machine keyring created in integrity code by adding
a reference. Store a reference to the machine keyring in
system keyring code. The system keyring code needs this to complete
the keyring link to the machine keyring.

Signed-off-by: Eric Snowberg <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
Tested-by: Mimi Zohar <[email protected]>
Signed-off-by: Jarkko Sakkinen <[email protected]>

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ima: enable loading of build time generated key on .ima keyring

The kernel currently only loads the kernel module signing key onto the
builtin trusted keyring. Load the module signing key onto the I

ima: enable loading of build time generated key on .ima keyring

The kernel currently only loads the kernel module signing key onto the
builtin trusted keyring. Load the module signing key onto the IMA keyring
as well.

Signed-off-by: Nayna Jain <[email protected]>
Acked-by: Stefan Berger <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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certs: Add EFI_CERT_X509_GUID support for dbx entries

This fixes CVE-2020-26541.

The Secure Boot Forbidden Signature Database, dbx, contains a list of now
revoked signatures and keys previously app

certs: Add EFI_CERT_X509_GUID support for dbx entries

This fixes CVE-2020-26541.

The Secure Boot Forbidden Signature Database, dbx, contains a list of now
revoked signatures and keys previously approved to boot with UEFI Secure
Boot enabled. The dbx is capable of containing any number of
EFI_CERT_X509_SHA256_GUID, EFI_CERT_SHA256_GUID, and EFI_CERT_X509_GUID
entries.

Currently when EFI_CERT_X509_GUID are contained in the dbx, the entries are
skipped.

Add support for EFI_CERT_X509_GUID dbx entries. When a EFI_CERT_X509_GUID
is found, it is added as an asymmetrical key to the .blacklist keyring.
Anytime the .platform keyring is used, the keys in the .blacklist keyring
are referenced, if a matching key is found, the key will be rejected.

[DH: Made the following changes:
- Added to have a config option to enable the facility. This allows a
Kconfig solution to make sure that pkcs7_validate_trust() is
enabled.[1][2]
- Moved the functions out from the middle of the blacklist functions.
- Added kerneldoc comments.]

Signed-off-by: Eric Snowberg <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jarkko Sakkinen <[email protected]>
cc: Randy Dunlap <[email protected]>
cc: Mickaël Salaün <[email protected]>
cc: Arnd Bergmann <[email protected]>
cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]/ # rfc
Link: https://lore.kernel.org/r/[email protected]/ # v2
Link: https://lore.kernel.org/r/[email protected]/ # v3
Link: https://lore.kernel.org/r/[email protected]/ # v4
Link: https://lore.kernel.org/r/[email protected]/ # v5
Link: https://lore.kernel.org/r/161428672051.677100.11064981943343605138.stgit@warthog.procyon.org.uk/
Link: https://lore.kernel.org/r/161433310942.902181.4901864302675874242.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/161529605075.163428.14625520893961300757.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/[email protected]/ [1]
Link: https://lore.kernel.org/r/[email protected]/ [2]

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certs: Add wrapper function to check blacklisted binary hash

The -EKEYREJECTED error returned by existing is_hash_blacklisted() is
misleading when called for checking against blacklisted hash of a
b

certs: Add wrapper function to check blacklisted binary hash

The -EKEYREJECTED error returned by existing is_hash_blacklisted() is
misleading when called for checking against blacklisted hash of a
binary.

This patch adds a wrapper function is_binary_blacklisted() to return
-EPERM error if binary is blacklisted.

Signed-off-by: Nayna Jain <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public licence as published by
the free software foundation either version 2 of the licence or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 114 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Reviewed-by: Kate Stewart <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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integrity, KEYS: add a reference to platform keyring

commit 9dc92c45177a ("integrity: Define a trusted platform keyring")
introduced a .platform keyring for storing preboot keys, used for
verifying

integrity, KEYS: add a reference to platform keyring

commit 9dc92c45177a ("integrity: Define a trusted platform keyring")
introduced a .platform keyring for storing preboot keys, used for
verifying kernel image signatures. Currently only IMA-appraisal is able
to use the keyring to verify kernel images that have their signature
stored in xattr.

This patch exposes the .platform keyring, making it accessible for
verifying PE signed kernel images as well.

Suggested-by: Mimi Zohar <[email protected]>
Signed-off-by: Kairui Song <[email protected]>
Cc: David Howells <[email protected]>
[[email protected]: fixed checkpatch errors, squashed with patch fix]
Signed-off-by: Mimi Zohar <[email protected]>

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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

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 <[email protected]>

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KEYS: Add a system blacklist keyring

Add the following:

(1) A new system keyring that is used to store information about
blacklisted certificates and signatures.

(2) A new key type (called

KEYS: Add a system blacklist keyring

Add the following:

(1) A new system keyring that is used to store information about
blacklisted certificates and signatures.

(2) A new key type (called 'blacklist') that is used to store a
blacklisted hash in its description as a hex string. The key accepts
no payload.

(3) The ability to configure a list of blacklisted hashes into the kernel
at build time. This is done by setting
CONFIG_SYSTEM_BLACKLIST_HASH_LIST to the filename of a list of hashes
that are in the form:

"<hash>", "<hash>", ..., "<hash>"

where each <hash> is a hex string representation of the hash and must
include all necessary leading zeros to pad the hash to the right size.

The above are enabled with CONFIG_SYSTEM_BLACKLIST_KEYRING.

Once the kernel is booted, the blacklist keyring can be listed:

root@andromeda ~]# keyctl show %:.blacklist
Keyring
723359729 ---lswrv 0 0 keyring: .blacklist
676257228 ---lswrv 0 0 \_ blacklist: 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46

The blacklist cannot currently be modified by userspace, but it will be
possible to load it, for example, from the UEFI blacklist database.

A later commit will make it possible to load blacklisted asymmetric keys in
here too.

Signed-off-by: David Howells <[email protected]>

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IMA: Use the the system trusted keyrings instead of .ima_mok

Add a config option (IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY)
that, when enabled, allows keys to be added to the IMA keyrings

IMA: Use the the system trusted keyrings instead of .ima_mok

Add a config option (IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY)
that, when enabled, allows keys to be added to the IMA keyrings by
userspace - with the restriction that each must be signed by a key in the
system trusted keyrings.

EPERM will be returned if this option is disabled, ENOKEY will be returned if
no authoritative key can be found and EKEYREJECTED will be returned if the
signature doesn't match. Other errors such as ENOPKG may also be returned.

If this new option is enabled, the builtin system keyring is searched, as is
the secondary system keyring if that is also enabled. Intermediate keys
between the builtin system keyring and the key being added can be added to
the secondary keyring (which replaces .ima_mok) to form a trust chain -
provided they are also validly signed by a key in one of the trusted keyrings.

The .ima_mok keyring is then removed and the IMA blacklist keyring gets its
own config option (IMA_BLACKLIST_KEYRING).

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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certs: Add a secondary system keyring that can be added to dynamically

Add a secondary system keyring that can be added to by root whilst the
system is running - provided the key being added is vouc

certs: Add a secondary system keyring that can be added to dynamically

Add a secondary system keyring that can be added to by root whilst the
system is running - provided the key being added is vouched for by a key
built into the kernel or already added to the secondary keyring.

Rename .system_keyring to .builtin_trusted_keys to distinguish it more
obviously from the new keyring (called .secondary_trusted_keys).

The new keyring needs to be enabled with CONFIG_SECONDARY_TRUSTED_KEYRING.

If the secondary keyring is enabled, a link is created from that to
.builtin_trusted_keys so that the the latter will automatically be searched
too if the secondary keyring is searched.

Signed-off-by: David Howells <[email protected]>

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KEYS: Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED

Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED as they're no longer
meaningful. Also we can drop the trusted flag from the preparse structure.

Gi

KEYS: Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED

Remove KEY_FLAG_TRUSTED and KEY_ALLOC_TRUSTED as they're no longer
meaningful. Also we can drop the trusted flag from the preparse structure.

Given this, we no longer need to pass the key flags through to
restrict_link().

Further, we can now get rid of keyring_restrict_trusted_only() also.

Signed-off-by: David Howells <[email protected]>

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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 t

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 <[email protected]>

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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 stuf

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 <[email protected]>

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IMA: create machine owner and blacklist keyrings

This option creates IMA MOK and blacklist keyrings. IMA MOK is an
intermediate keyring that sits between .system and .ima keyrings,
effectively form

IMA: create machine owner and blacklist keyrings

This option creates IMA MOK and blacklist keyrings. IMA MOK is an
intermediate keyring that sits between .system and .ima keyrings,
effectively forming a simple CA hierarchy. To successfully import a key
into .ima_mok it must be signed by a key which CA is in .system keyring.
On turn any key that needs to go in .ima keyring must be signed by CA in
either .system or .ima_mok keyrings. IMA MOK is empty at kernel boot.

IMA blacklist keyring contains all revoked IMA keys. It is consulted
before any other keyring. If the search is successful the requested
operation is rejected and error is returned to the caller.

Signed-off-by: Petko Manolov <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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PKCS#7: Appropriately restrict authenticated attributes and content type

A PKCS#7 or CMS message can have per-signature authenticated attributes
that are digested as a lump and signed by the authori

PKCS#7: Appropriately restrict authenticated attributes and content type

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 <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Marcel Holtmann <[email protected]>
Reviewed-by: David Woodhouse <[email protected]>

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MODSIGN: Extract the blob PKCS#7 signature verifier from module signing

Extract the function that drives the PKCS#7 signature verification given a
data blob and a PKCS#7 blob out from the module sig

MODSIGN: Extract the blob PKCS#7 signature verifier from module signing

Extract the function that drives the PKCS#7 signature verification given a
data blob and a PKCS#7 blob out from the module signing code and lump it with
the system keyring code as it's generic. This makes it independent of module
config options and opens it to use by the firmware loader.

Signed-off-by: David Howells <[email protected]>
Cc: Luis R. Rodriguez <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Ming Lei <[email protected]>
Cc: Seth Forshee <[email protected]>
Cc: Kyle McMartin <[email protected]>

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KEYS: verify a certificate is signed by a 'trusted' key

Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring.

KEYS: verify a certificate is signed by a 'trusted' key

Only public keys, with certificates signed by an existing
'trusted' key on the system trusted keyring, should be added
to a trusted keyring. This patch adds support for verifying
a certificate's signature.

This is derived from David Howells pkcs7_request_asymmetric_key() patch.

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

Changelog:
- define get_system_trusted_keyring() to fix kbuild issues

Signed-off-by: Mimi Zohar <[email protected]>
Signed-off-by: David Howells <[email protected]>
Acked-by: Dmitry Kasatkin <[email protected]>

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KEYS: Separate the kernel signature checking keyring from module signing

Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signi

KEYS: Separate the kernel signature checking keyring from module signing

Separate the kernel signature checking keyring from module signing so that it
can be used by code other than the module-signing code.

Signed-off-by: David Howells <[email protected]>

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