Revert "crypto: pkcs7 - remove sha1 support"

This reverts commit 16ab7cb5825fc3425c16ad2c6e53d827f382d7c6 because it
broke iwd. iwd uses the KEYCTL_PKEY_* UAPIs via its dependency libell,
and apparently it is relying on SHA-1 signature support. These UAPIs
are fairly obscure, and their documentation does not mention which
algorithms they support. iwd really should be using a properly
supported userspace crypto library instead. Regardless, since something
broke we have to revert the change.

It may be possible that some parts of this commit can be reinstated
without breaking iwd (e.g. probably the removal of MODULE_SIG_SHA1), but
for now this just does a full revert to get things working again.

Reported-by: Karel Balej <balejk@matfyz.cz>
Closes: https://lore.kernel.org/r/CZSHRUIJ4RKL.34T4EASV5DNJM@matfyz.cz
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Karel Balej <balejk@matfyz.cz>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: asymmetric_keys - allow FIPS 202 SHA-3 signatures

Add FIPS 202 SHA-3 hash signature support in x509 certificates, pkcs7
signatures, and authenticode signatures. Supports hashes of size 256
and up, as 224 is too weak for any practical purposes.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: pkcs7 - remove sha1 support

Removes support for sha1 signed kernel modules, importing sha1 signed
x.509 certificates.

rsa-pkcs1pad keeps sha1 padding support, which seems to be used by
virtio driver.

sha1 remains available as there are many drivers and subsystems using
it. Note only hmac(sha1) with secret keys remains cryptographically
secure.

In the kernel there are filesystems, IMA, tpm/pcr that appear to be
using sha1. Maybe they can all start to be slowly upgraded to
something else i.e. blake3, ParallelHash, SHAKE256 as needed.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: pkcs7 - remove md4 md5 x.509 support

Remove support for md4 md5 hash and signatures in x.509 certificate
parsers, pkcs7 signature parser, authenticode parser.

All of these are insecure or broken, and everyone has long time ago
migrated to alternative hash implementations.

Also remove md2 & md3 oids which have already didn't have support.

This is also likely the last user of md4 in the kernel, and thus
crypto/md4.c and related tests in tcrypt & testmgr can likely be
removed. Other users such as cifs smbfs ext modpost sumversions have
their own internal implementation as needed.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

pkcs7: support EC-RDSA/streebog in SignerInfo

Allow using EC-RDSA/streebog in pkcs7 certificates in a similar way
to how it's done in the x509 parser.

This is needed e.g. for loading kernel modules signed with EC-RDSA.

Signed-off-by: Elvira Khabirova <e.khabirova@omp.ru>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

pkcs7: parser support SM2 and SM3 algorithms combination

Support parsing the message signature of the SM2 and SM3 algorithm
combination. This group of algorithms has been well supported. One
of the main users is module signature verification.

Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

certs: Add support for using elliptic curve keys for signing modules

Add support for using elliptic curve keys for signing modules. It uses
a NIST P384 (secp384r1) key if the user chooses an elliptic curve key
and will have ECDSA support built into the kernel.

Note: A developer choosing an ECDSA key for signing modules should still
delete the signing key (rm certs/signing_key.*) when building an older
version of a kernel that only supports RSA keys. Unless kbuild automati-
cally detects and generates a new kernel module key, ECDSA-signed kernel
modules will fail signature verification.

Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

KEYS: Make the X.509 and PKCS7 parsers supply the sig encoding type [ver #2]

Make the X.509 and PKCS7 parsers fill in the signature encoding type field
recently added to the public_key_signature struct.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Tested-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

kbuild: rename *-asn1.[ch] to *.asn1.[ch]

Our convention is to distinguish file types by suffixes with a period
as a separator.

*-asn1.[ch] is a different pattern from other generated sources such
as *.lex.c, *.tab.[ch], *.dtb.S, etc. More confusing, files with
'-asn1.[ch]' are generated files, but '_asn1.[ch]' are checked-in
files:
net/netfilter/nf_conntrack_h323_asn1.c
include/linux/netfilter/nf_conntrack_h323_asn1.h
include/linux/sunrpc/gss_asn1.h

Rename generated files to *.asn1.[ch] for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

pkcs7: return correct error code if pkcs7_check_authattrs() fails

If pkcs7_check_authattrs() returns an error code, we should pass that
error code on, rather than using ENOMEM.

Fixes: 99db44350672 ("PKCS#7: Appropriately restrict authenticated attributes and content type")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>

pkcs7: Set the module licence to prevent tainting

Set the module licence to prevent the kernel from being tainted if loaded
as a module.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>

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: 99db44350672 ("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+

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>

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>

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: 07f081fb5057 ("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>

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>

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>

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>

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>

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>

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>

PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them

Add OIDs for sha224, sha284 and sha512 hash algos and use them to select
the hashing algorithm. Without this, something like the following error
might get written to dmesg:

[ 31.829322] PKCS7: Unknown OID: [32] 2.16.840.1.101.3.4.2.3
[ 31.829328] PKCS7: Unknown OID: [180] 2.16.840.1.101.3.4.2.3
[ 31.829330] Unsupported digest algo: 55

Where the 55 on the third line is OID__NR indicating an unknown OID.

Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-By: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: James Morris <james.l.morris@oracle.com>

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 <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>

PKCS#7: Support CMS messages also [RFC5652]

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>

PKCS#7: Check content type and versions

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>

KEYS: Overhaul key identification when searching for asymmetric keys

Make use of the new match string preparsing to overhaul key identification
when searching for asymmetric keys. The following changes are made:

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

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

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

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

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

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

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

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

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

Additional changes:

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

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

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

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

PKCS#7: Fix the parser cleanup to drain parsed out X.509 certs

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>

PKCS#7: Provide a single place to do signed info block freeing

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>

PKCS#7: Implement a parser [RFC 2315]

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>