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>
David Howells