Commit cd3bc044af ("KEYS: encrypted: Instantiate key with
user-provided decrypted data") added key instantiation with user
provided decrypted data. The user data is hex-ascii-encoded but was
just memcpy'ed to the binary buffer. Fix this to use hex2bin instead.
Old keys created from user provided decrypted data saved with "keyctl
pipe" are still valid, however if the key is recreated from decrypted
data the old key must be converted to the correct format. This can be
done with a small shell script, e.g.:
BROKENKEY=abcdefABCDEF1234567890aaaaaaaaaa
NEWKEY=$(echo -ne $BROKENKEY | xxd -p -c32)
keyctl add user masterkey "$(cat masterkey.bin)" @u
keyctl add encrypted testkey "new user:masterkey 32 $NEWKEY" @u
However, NEWKEY is still broken: If for BROKENKEY 32 bytes were
specified, a brute force attacker knowing the key properties would only
need to try at most 2^(16*8) keys, as if the key was only 16 bytes long.
The security issue is a result of the combination of limiting the input
range to hex-ascii and using memcpy() instead of hex2bin(). It could
have been fixed either by allowing binary input or using hex2bin() (and
doubling the ascii input key length). This patch implements the latter.
The corresponding test for the Linux Test Project ltp has also been
fixed (see link below).
Fixes: cd3bc044af ("KEYS: encrypted: Instantiate key with user-provided decrypted data")
Cc: stable@kernel.org
Link: https://lore.kernel.org/ltp/20221006081709.92303897@mail.steuer-voss.de/
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Nikolaus Voss <nikolaus.voss@haag-streit.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Update documentation for trusted key use with the Cryptographic
Acceleration and Assurance Module (CAAM), an IP on NXP SoCs.
Reviewed-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
The two existing trusted key sources don't make use of the kernel RNG,
but instead let the hardware doing the sealing/unsealing also
generate the random key material. However, both users and future
backends may want to place less trust into the quality of the trust
source's random number generator and instead reuse the kernel entropy
pool, which can be seeded from multiple entropy sources.
Make this possible by adding a new trusted.rng parameter,
that will force use of the kernel RNG. In its absence, it's up
to the trust source to decide, which random numbers to use,
maintaining the existing behavior.
Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Acked-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Reviewed-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Tested-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Tested-by: Michael Walle <michael@walle.cc> # on ls1028a (non-E and E)
Tested-by: John Ernberg <john.ernberg@actia.se> # iMX8QXP
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
For availability and performance reasons master keys often need to be
released outside of a Key Management Service (KMS) to clients. It
would be beneficial to provide a mechanism where the
wrapping/unwrapping of data encryption keys (DEKs) is not dependent
on a remote call at runtime yet security is not (or only minimally)
compromised. Master keys could be securely stored in the Kernel and
be used to wrap/unwrap keys from Userspace.
The encrypted.c class supports instantiation of encrypted keys with
either an already-encrypted key material, or by generating new key
material based on random numbers. This patch defines a new datablob
format: [<format>] <master-key name> <decrypted data length>
<decrypted data> that allows to inject and encrypt user-provided
decrypted data. The decrypted data must be hex-ascii encoded.
Signed-off-by: Yael Tzur <yaelt@google.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Update documentation for Trusted and Encrypted Keys with TEE as a new
trust source. Following is brief description of updates:
- Add a section to demonstrate a list of supported devices along with
their security properties/guarantees.
- Add a key generation section.
- Updates for usage section including differences specific to a trust
source.
Co-developed-by: Elaine Palmer <erpalmer@us.ibm.com>
Signed-off-by: Elaine Palmer <erpalmer@us.ibm.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Modify the TPM2 key format blob output to export and import in the
ASN.1 form for TPM2 sealed object keys. For compatibility with prior
trusted keys, the importer will also accept two TPM2B quantities
representing the public and private parts of the key. However, the
export via keyctl pipe will only output the ASN.1 format.
The benefit of the ASN.1 format is that it's a standard and thus the
exported key can be used by userspace tools (openssl_tpm2_engine,
openconnect and tpm2-tss-engine). The format includes policy
specifications, thus it gets us out of having to construct policy
handles in userspace and the format includes the parent meaning you
don't have to keep passing it in each time.
This patch only implements basic handling for the ASN.1 format, so
keys with passwords but no policy.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
The parameters in command examples for tpm2_createprimary and
tpm2_evictcontrol are outdated, people (like me) are not able to create
trusted key by these command examples.
This patch updates the parameters of command example tpm2_createprimary
and tpm2_evictcontrol in trusted-encrypted.rst. With Linux kernel v5.8
and tpm2-tools-4.1, people can create a trusted key by following the
examples in this document.
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Peter Huewe <peterhuewe@gmx.de>
Link: https://lore.kernel.org/r/20200821135356.15737-1-colyli@suse.de
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The code-block tag is at the wrong place, causing those
warnings:
Documentation/security/keys/trusted-encrypted.rst:112: WARNING: Literal block expected; none found.
Documentation/security/keys/trusted-encrypted.rst:121: WARNING: Unexpected indentation.
Documentation/security/keys/trusted-encrypted.rst:122: WARNING: Block quote ends without a blank line; unexpected unindent.
Documentation/security/keys/trusted-encrypted.rst:123: WARNING: Block quote ends without a blank line; unexpected unindent.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull integrity updates from James Morris:
"In Linux 4.19, a new LSM hook named security_kernel_load_data was
upstreamed, allowing LSMs and IMA to prevent the kexec_load syscall.
Different signature verification methods exist for verifying the
kexec'ed kernel image. This adds additional support in IMA to prevent
loading unsigned kernel images via the kexec_load syscall,
independently of the IMA policy rules, based on the runtime "secure
boot" flag. An initial IMA kselftest is included.
In addition, this pull request defines a new, separate keyring named
".platform" for storing the preboot/firmware keys needed for verifying
the kexec'ed kernel image's signature and includes the associated IMA
kexec usage of the ".platform" keyring.
(David Howell's and Josh Boyer's patches for reading the
preboot/firmware keys, which were previously posted for a different
use case scenario, are included here)"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
integrity: Remove references to module keyring
ima: Use inode_is_open_for_write
ima: Support platform keyring for kernel appraisal
efi: Allow the "db" UEFI variable to be suppressed
efi: Import certificates from UEFI Secure Boot
efi: Add an EFI signature blob parser
efi: Add EFI signature data types
integrity: Load certs to the platform keyring
integrity: Define a trusted platform keyring
selftests/ima: kexec_load syscall test
ima: don't measure/appraise files on efivarfs
x86/ima: retry detecting secure boot mode
docs: Extend trusted keys documentation for TPM 2.0
x86/ima: define arch_get_ima_policy() for x86
ima: add support for arch specific policies
ima: refactor ima_init_policy()
ima: prevent kexec_load syscall based on runtime secureboot flag
x86/ima: define arch_ima_get_secureboot
integrity: support new struct public_key_signature encoding field
Adding nvdimm key format type to encrypted keys in order to limit the size
of the key to 32bytes.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Extend the documentation for trusted keys with documentation for how to
set up a key for a TPM 2.0 so it can be used with a TPM 2.0 as well.
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Several paths in the security/keys documentation were incorrect.
Signed-off-by: Josh Holland <anowlcalledjosh@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
