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Author SHA1 Message Date
Greg Kroah-Hartman 867c10a03f crypto: asym_tpm: correct zero out potential secrets
commit f93274ef0f upstream.

The function derive_pub_key() should be calling memzero_explicit()
instead of memset() in case the complier decides to optimize away the
call to memset() because it "knows" no one is going to touch the memory
anymore.

Cc: stable <stable@vger.kernel.org>
Reported-by: Ilil Blum Shem-Tov <ilil.blum.shem-tov@intel.com>
Tested-by: Ilil Blum Shem-Tov <ilil.blum.shem-tov@intel.com>
Link: https://lore.kernel.org/r/X8ns4AfwjKudpyfe@kroah.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12 20:16:17 +01:00
Wei Yongjun f62d7f91af keys: asymmetric: fix error return code in software_key_query()
[ Upstream commit 6cbba1f911 ]

Fix to return negative error code -ENOMEM from kmalloc() error handling
case instead of 0, as done elsewhere in this function.

Fixes: f1774cb895 ("X.509: parse public key parameters from x509 for akcipher")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-07-22 09:33:04 +02:00
Eric Biggers 36cd99cf68 KEYS: asymmetric: return ENOMEM if akcipher_request_alloc() fails
commit bea3741445 upstream.

No error code was being set on this error path.

Cc: stable@vger.kernel.org
Fixes: ad4b1eb5fb ("KEYS: asym_tpm: Implement encryption operation [ver #2]")
Fixes: c08fed7371 ("KEYS: Implement encrypt, decrypt and sign for software asymmetric key [ver #2]")
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-31 16:46:07 +01:00
Linus Torvalds aefcf2f4b5 Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull kernel lockdown mode from James Morris:
 "This is the latest iteration of the kernel lockdown patchset, from
  Matthew Garrett, David Howells and others.

  From the original description:

    This patchset introduces an optional kernel lockdown feature,
    intended to strengthen the boundary between UID 0 and the kernel.
    When enabled, various pieces of kernel functionality are restricted.
    Applications that rely on low-level access to either hardware or the
    kernel may cease working as a result - therefore this should not be
    enabled without appropriate evaluation beforehand.

    The majority of mainstream distributions have been carrying variants
    of this patchset for many years now, so there's value in providing a
    doesn't meet every distribution requirement, but gets us much closer
    to not requiring external patches.

  There are two major changes since this was last proposed for mainline:

   - Separating lockdown from EFI secure boot. Background discussion is
     covered here: https://lwn.net/Articles/751061/

   -  Implementation as an LSM, with a default stackable lockdown LSM
      module. This allows the lockdown feature to be policy-driven,
      rather than encoding an implicit policy within the mechanism.

  The new locked_down LSM hook is provided to allow LSMs to make a
  policy decision around whether kernel functionality that would allow
  tampering with or examining the runtime state of the kernel should be
  permitted.

  The included lockdown LSM provides an implementation with a simple
  policy intended for general purpose use. This policy provides a coarse
  level of granularity, controllable via the kernel command line:

    lockdown={integrity|confidentiality}

  Enable the kernel lockdown feature. If set to integrity, kernel features
  that allow userland to modify the running kernel are disabled. If set to
  confidentiality, kernel features that allow userland to extract
  confidential information from the kernel are also disabled.

  This may also be controlled via /sys/kernel/security/lockdown and
  overriden by kernel configuration.

  New or existing LSMs may implement finer-grained controls of the
  lockdown features. Refer to the lockdown_reason documentation in
  include/linux/security.h for details.

  The lockdown feature has had signficant design feedback and review
  across many subsystems. This code has been in linux-next for some
  weeks, with a few fixes applied along the way.

  Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
  when kernel lockdown is in confidentiality mode") is missing a
  Signed-off-by from its author. Matthew responded that he is providing
  this under category (c) of the DCO"

* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
  kexec: Fix file verification on S390
  security: constify some arrays in lockdown LSM
  lockdown: Print current->comm in restriction messages
  efi: Restrict efivar_ssdt_load when the kernel is locked down
  tracefs: Restrict tracefs when the kernel is locked down
  debugfs: Restrict debugfs when the kernel is locked down
  kexec: Allow kexec_file() with appropriate IMA policy when locked down
  lockdown: Lock down perf when in confidentiality mode
  bpf: Restrict bpf when kernel lockdown is in confidentiality mode
  lockdown: Lock down tracing and perf kprobes when in confidentiality mode
  lockdown: Lock down /proc/kcore
  x86/mmiotrace: Lock down the testmmiotrace module
  lockdown: Lock down module params that specify hardware parameters (eg. ioport)
  lockdown: Lock down TIOCSSERIAL
  lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
  acpi: Disable ACPI table override if the kernel is locked down
  acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
  ACPI: Limit access to custom_method when the kernel is locked down
  x86/msr: Restrict MSR access when the kernel is locked down
  x86: Lock down IO port access when the kernel is locked down
  ...
2019-09-28 08:14:15 -07:00
Jiri Bohac 99d5cadfde kexec_file: split KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE
This is a preparatory patch for kexec_file_load() lockdown.  A locked down
kernel needs to prevent unsigned kernel images from being loaded with
kexec_file_load().  Currently, the only way to force the signature
verification is compiling with KEXEC_VERIFY_SIG.  This prevents loading
usigned images even when the kernel is not locked down at runtime.

This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE.
Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG
turns on the signature verification but allows unsigned images to be
loaded.  KEXEC_SIG_FORCE disallows images without a valid signature.

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
cc: kexec@lists.infradead.org
Signed-off-by: James Morris <jmorris@namei.org>
2019-08-19 21:54:15 -07:00
Thiago Jung Bauermann e201af16d1 PKCS#7: Introduce pkcs7_get_digest()
IMA will need to access the digest of the PKCS7 message (as calculated by
the kernel) before the signature is verified, so introduce
pkcs7_get_digest() for that purpose.

Also, modify pkcs7_digest() to detect when the digest was already
calculated so that it doesn't have to do redundant work. Verifying that
sinfo->sig->digest isn't NULL is sufficient because both places which
allocate sinfo->sig (pkcs7_parse_message() and pkcs7_note_signed_info())
use kzalloc() so sig->digest is always initialized to zero.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-08-05 18:40:19 -04:00
Linus Torvalds 4d2fa8b44b Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto updates from Herbert Xu:
 "Here is the crypto update for 5.3:

  API:
   - Test shash interface directly in testmgr
   - cra_driver_name is now mandatory

  Algorithms:
   - Replace arc4 crypto_cipher with library helper
   - Implement 5 way interleave for ECB, CBC and CTR on arm64
   - Add xxhash
   - Add continuous self-test on noise source to drbg
   - Update jitter RNG

  Drivers:
   - Add support for SHA204A random number generator
   - Add support for 7211 in iproc-rng200
   - Fix fuzz test failures in inside-secure
   - Fix fuzz test failures in talitos
   - Fix fuzz test failures in qat"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (143 commits)
  crypto: stm32/hash - remove interruptible condition for dma
  crypto: stm32/hash - Fix hmac issue more than 256 bytes
  crypto: stm32/crc32 - rename driver file
  crypto: amcc - remove memset after dma_alloc_coherent
  crypto: ccp - Switch to SPDX license identifiers
  crypto: ccp - Validate the the error value used to index error messages
  crypto: doc - Fix formatting of new crypto engine content
  crypto: doc - Add parameter documentation
  crypto: arm64/aes-ce - implement 5 way interleave for ECB, CBC and CTR
  crypto: arm64/aes-ce - add 5 way interleave routines
  crypto: talitos - drop icv_ool
  crypto: talitos - fix hash on SEC1.
  crypto: talitos - move struct talitos_edesc into talitos.h
  lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE
  crypto/NX: Set receive window credits to max number of CRBs in RxFIFO
  crypto: asymmetric_keys - select CRYPTO_HASH where needed
  crypto: serpent - mark __serpent_setkey_sbox noinline
  crypto: testmgr - dynamically allocate crypto_shash
  crypto: testmgr - dynamically allocate testvec_config
  crypto: talitos - eliminate unneeded 'done' functions at build time
  ...
2019-07-08 20:57:08 -07:00
Linus Torvalds c84ca912b0 Keyrings namespacing
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Merge tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull keyring namespacing from David Howells:
 "These patches help make keys and keyrings more namespace aware.

  Firstly some miscellaneous patches to make the process easier:

   - Simplify key index_key handling so that the word-sized chunks
     assoc_array requires don't have to be shifted about, making it
     easier to add more bits into the key.

   - Cache the hash value in the key so that we don't have to calculate
     on every key we examine during a search (it involves a bunch of
     multiplications).

   - Allow keying_search() to search non-recursively.

  Then the main patches:

   - Make it so that keyring names are per-user_namespace from the point
     of view of KEYCTL_JOIN_SESSION_KEYRING so that they're not
     accessible cross-user_namespace.

     keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEYRING_NAME for this.

   - Move the user and user-session keyrings to the user_namespace
     rather than the user_struct. This prevents them propagating
     directly across user_namespaces boundaries (ie. the KEY_SPEC_*
     flags will only pick from the current user_namespace).

   - Make it possible to include the target namespace in which the key
     shall operate in the index_key. This will allow the possibility of
     multiple keys with the same description, but different target
     domains to be held in the same keyring.

     keyctl_capabilities() shows KEYCTL_CAPS1_NS_KEY_TAG for this.

   - Make it so that keys are implicitly invalidated by removal of a
     domain tag, causing them to be garbage collected.

   - Institute a network namespace domain tag that allows keys to be
     differentiated by the network namespace in which they operate. New
     keys that are of a type marked 'KEY_TYPE_NET_DOMAIN' are assigned
     the network domain in force when they are created.

   - Make it so that the desired network namespace can be handed down
     into the request_key() mechanism. This allows AFS, NFS, etc. to
     request keys specific to the network namespace of the superblock.

     This also means that the keys in the DNS record cache are
     thenceforth namespaced, provided network filesystems pass the
     appropriate network namespace down into dns_query().

     For DNS, AFS and NFS are good, whilst CIFS and Ceph are not. Other
     cache keyrings, such as idmapper keyrings, also need to set the
     domain tag - for which they need access to the network namespace of
     the superblock"

* tag 'keys-namespace-20190627' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  keys: Pass the network namespace into request_key mechanism
  keys: Network namespace domain tag
  keys: Garbage collect keys for which the domain has been removed
  keys: Include target namespace in match criteria
  keys: Move the user and user-session keyrings to the user_namespace
  keys: Namespace keyring names
  keys: Add a 'recurse' flag for keyring searches
  keys: Cache the hash value to avoid lots of recalculation
  keys: Simplify key description management
2019-07-08 19:36:47 -07:00
Arnd Bergmann 90acc0653d crypto: asymmetric_keys - select CRYPTO_HASH where needed
Build testing with some core crypto options disabled revealed
a few modules that are missing CRYPTO_HASH:

crypto/asymmetric_keys/x509_public_key.o: In function `x509_get_sig_params':
x509_public_key.c:(.text+0x4c7): undefined reference to `crypto_alloc_shash'
x509_public_key.c:(.text+0x5e5): undefined reference to `crypto_shash_digest'
crypto/asymmetric_keys/pkcs7_verify.o: In function `pkcs7_digest.isra.0':
pkcs7_verify.c:(.text+0xab): undefined reference to `crypto_alloc_shash'
pkcs7_verify.c:(.text+0x1b2): undefined reference to `crypto_shash_digest'
pkcs7_verify.c:(.text+0x3c1): undefined reference to `crypto_shash_update'
pkcs7_verify.c:(.text+0x411): undefined reference to `crypto_shash_finup'

This normally doesn't show up in randconfig tests because there is
a large number of other options that select CRYPTO_HASH.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-06-27 14:28:01 +08:00
David Howells dcf49dbc80 keys: Add a 'recurse' flag for keyring searches
Add a 'recurse' flag for keyring searches so that the flag can be omitted
and recursion disabled, thereby allowing just the nominated keyring to be
searched and none of the children.

Signed-off-by: David Howells <dhowells@redhat.com>
2019-06-26 21:02:32 +01:00
Thomas Gleixner b4d0d230cc 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>
2019-05-24 17:27:11 +02:00
Eric Biggers 877b5691f2 crypto: shash - remove shash_desc::flags
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.

With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP.  These would all need to be fixed if any shash algorithm
actually started sleeping.  For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API.  However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.

Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk.  It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.

Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-25 15:38:12 +08:00
Vitaly Chikunov 0d7a78643f crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm
Add Elliptic Curve Russian Digital Signature Algorithm (GOST R
34.10-2012, RFC 7091, ISO/IEC 14888-3) is one of the Russian (and since
2018 the CIS countries) cryptographic standard algorithms (called GOST
algorithms). Only signature verification is supported, with intent to be
used in the IMA.

Summary of the changes:

* crypto/Kconfig:
  - EC-RDSA is added into Public-key cryptography section.

* crypto/Makefile:
  - ecrdsa objects are added.

* crypto/asymmetric_keys/x509_cert_parser.c:
  - Recognize EC-RDSA and Streebog OIDs.

* include/linux/oid_registry.h:
  - EC-RDSA OIDs are added to the enum. Also, a two currently not
    implemented curve OIDs are added for possible extension later (to
    not change numbering and grouping).

* crypto/ecc.c:
  - Kenneth MacKay copyright date is updated to 2014, because
    vli_mmod_slow, ecc_point_add, ecc_point_mult_shamir are based on his
    code from micro-ecc.
  - Functions needed for ecrdsa are EXPORT_SYMBOL'ed.
  - New functions:
    vli_is_negative - helper to determine sign of vli;
    vli_from_be64 - unpack big-endian array into vli (used for
      a signature);
    vli_from_le64 - unpack little-endian array into vli (used for
      a public key);
    vli_uadd, vli_usub - add/sub u64 value to/from vli (used for
      increment/decrement);
    mul_64_64 - optimized to use __int128 where appropriate, this speeds
      up point multiplication (and as a consequence signature
      verification) by the factor of 1.5-2;
    vli_umult - multiply vli by a small value (speeds up point
      multiplication by another factor of 1.5-2, depending on vli sizes);
    vli_mmod_special - module reduction for some form of Pseudo-Mersenne
      primes (used for the curves A);
    vli_mmod_special2 - module reduction for another form of
      Pseudo-Mersenne primes (used for the curves B);
    vli_mmod_barrett - module reduction using pre-computed value (used
      for the curve C);
    vli_mmod_slow - more general module reduction which is much slower
     (used when the modulus is subgroup order);
    vli_mod_mult_slow - modular multiplication;
    ecc_point_add - add two points;
    ecc_point_mult_shamir - add two points multiplied by scalars in one
      combined multiplication (this gives speed up by another factor 2 in
      compare to two separate multiplications).
    ecc_is_pubkey_valid_partial - additional samity check is added.
  - Updated vli_mmod_fast with non-strict heuristic to call optimal
      module reduction function depending on the prime value;
  - All computations for the previously defined (two NIST) curves should
    not unaffected.

* crypto/ecc.h:
  - Newly exported functions are documented.

* crypto/ecrdsa_defs.h
  - Five curves are defined.

* crypto/ecrdsa.c:
  - Signature verification is implemented.

* crypto/ecrdsa_params.asn1, crypto/ecrdsa_pub_key.asn1:
  - Templates for BER decoder for EC-RDSA parameters and public key.

Cc: linux-integrity@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-18 22:15:02 +08:00
Vitaly Chikunov f1774cb895 X.509: parse public key parameters from x509 for akcipher
Some public key algorithms (like EC-DSA) keep in parameters field
important data such as digest and curve OIDs (possibly more for
different EC-DSA variants). Thus, just setting a public key (as
for RSA) is not enough.

Append parameters into the key stream for akcipher_set_{pub,priv}_key.
Appended data is: (u32) algo OID, (u32) parameters length, parameters
data.

This does not affect current akcipher API nor RSA ciphers (they could
ignore it). Idea of appending parameters to the key stream is by Herbert
Xu.

Cc: David Howells <dhowells@redhat.com>
Cc: Denis Kenzior <denkenz@gmail.com>
Cc: keyrings@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-18 22:15:02 +08:00
Vitaly Chikunov 83bc029996 KEYS: do not kmemdup digest in {public,tpm}_key_verify_signature
Treat (struct public_key_signature)'s digest same as its signature (s).
Since digest should be already in the kmalloc'd memory do not kmemdup
digest value before calling {public,tpm}_key_verify_signature.

Patch is split from the previous as suggested by Herbert Xu.

Suggested-by: David Howells <dhowells@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-18 22:15:02 +08:00
Vitaly Chikunov c7381b0128 crypto: akcipher - new verify API for public key algorithms
Previous akcipher .verify() just `decrypts' (using RSA encrypt which is
using public key) signature to uncover message hash, which was then
compared in upper level public_key_verify_signature() with the expected
hash value, which itself was never passed into verify().

This approach was incompatible with EC-DSA family of algorithms,
because, to verify a signature EC-DSA algorithm also needs a hash value
as input; then it's used (together with a signature divided into halves
`r||s') to produce a witness value, which is then compared with `r' to
determine if the signature is correct. Thus, for EC-DSA, nor
requirements of .verify() itself, nor its output expectations in
public_key_verify_signature() wasn't sufficient.

Make improved .verify() call which gets hash value as input and produce
complete signature check without any output besides status.

Now for the top level verification only crypto_akcipher_verify() needs
to be called and its return value inspected.

Make sure that `digest' is in kmalloc'd memory (in place of `output`) in
{public,tpm}_key_verify_signature() as insisted by Herbert Xu, and will
be changed in the following commit.

Cc: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-18 22:15:02 +08:00
Denis Kenzior 64ae16dfee KEYS: asym_tpm: Add support for the sign operation [ver #2]
The sign operation can operate in a non-hashed mode by running the RSA
sign operation directly on the input.  This assumes that the input is
less than key_size_in_bytes - 11.  Since the TPM performs its own PKCS1
padding, it isn't possible to support 'raw' mode, only 'pkcs1'.

Alternatively, a hashed version is also possible.  In this variant the
input is hashed (by userspace) via the selected hash function first.
Then this implementation takes care of converting the hash to ASN.1
format and the sign operation is performed on the result.  This is
similar to the implementation inside crypto/rsa-pkcs1pad.c.

ASN1 templates were copied from crypto/rsa-pkcs1pad.c.  There seems to
be no easy way to expose that functionality, but likely the templates
should be shared somehow.

The sign operation is implemented via TPM_Sign operation on the TPM.
It is assumed that the TPM wrapped key provided uses
TPM_SS_RSASSAPKCS1v15_DER signature scheme.  This allows the TPM_Sign
operation to work on data up to key_len_in_bytes - 11 bytes long.

In theory, we could also use TPM_Unbind instead of TPM_Sign, but we would
have to manually pkcs1 pad the digest first.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior e73d170f6c KEYS: asym_tpm: Implement tpm_sign [ver #2]
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior e08e689123 KEYS: asym_tpm: Implement signature verification [ver #2]
This patch implements the verify_signature operation.  The public key
portion extracted from the TPM key blob is used.  The operation is
performed entirely in software using the crypto API.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior a335974ae0 KEYS: asym_tpm: Implement the decrypt operation [ver #2]
This patch implements the pkey_decrypt operation using the private key
blob.  The blob is first loaded into the TPM via tpm_loadkey2.  Once the
handle is obtained, tpm_unbind operation is used to decrypt the data on
the TPM and the result is returned.  The key loaded by tpm_loadkey2 is
then evicted via tpm_flushspecific operation.

This patch assumes that the SRK authorization is a well known 20-byte of
zeros and the same holds for the key authorization of the provided key.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior f884fe5a15 KEYS: asym_tpm: Implement tpm_unbind [ver #2]
Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior 0c36264aa1 KEYS: asym_tpm: Add loadkey2 and flushspecific [ver #2]
This commit adds TPM_LoadKey2 and TPM_FlushSpecific operations.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior e1ea9f8602 KEYS: trusted: Expose common functionality [ver #2]
This patch exposes some common functionality needed to send TPM commands.
Several functions from keys/trusted.c are exposed for use by the new tpm
key subtype and a module dependency is introduced.

In the future, common functionality between the trusted key type and the
asym_tpm subtype should be factored out into a common utility library.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior ad4b1eb5fb KEYS: asym_tpm: Implement encryption operation [ver #2]
This patch impelements the pkey_encrypt operation.  The public key
portion extracted from the TPM key blob is used.  The operation is
performed entirely in software using the crypto API.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:47 +01:00
Denis Kenzior dff5a61a59 KEYS: asym_tpm: Implement pkey_query [ver #2]
This commit implements the pkey_query operation.  This is accomplished
by utilizing the public key portion to obtain max encryption size
information for the operations that utilize the public key (encrypt,
verify).  The private key size extracted from the TPM_Key data structure
is used to fill the information where the private key is used (decrypt,
sign).

The kernel uses a DER/BER format for public keys and does not support
setting the key via the raw binary form.  To get around this a simple
DER/BER formatter is implemented which stores the DER/BER formatted key
and exponent in a temporary buffer for use by the crypto API.

The only exponent supported currently is 65537.  This holds true for
other Linux TPM tools such as 'create_tpm_key' and
trousers-openssl_tpm_engine.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
Denis Kenzior d5e72745ca KEYS: Add parser for TPM-based keys [ver #2]
For TPM based keys, the only standard seems to be described here:
http://david.woodhou.se/draft-woodhouse-cert-best-practice.html#rfc.section.4.4

Quote from the relevant section:
"Rather, a common form of storage for "wrapped" keys is to encode the
binary TCPA_KEY structure in a single ASN.1 OCTET-STRING, and store the
result in PEM format with the tag "-----BEGIN TSS KEY BLOB-----". "

This patch implements the above behavior.  It is assumed that the PEM
encoding is stripped out by userspace and only the raw DER/BER format is
provided.  This is similar to how PKCS7, PKCS8 and X.509 keys are
handled.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
Denis Kenzior f8c54e1ac4 KEYS: asym_tpm: extract key size & public key [ver #2]
The parsed BER/DER blob obtained from user space contains a TPM_Key
structure.  This structure has some information about the key as well as
the public key portion.

This patch extracts this information for future use.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
Denis Kenzior 903be6bb84 KEYS: asym_tpm: add skeleton for asym_tpm [ver #2]
This patch adds the basic skeleton for the asym_tpm asymmetric key
subtype.

Signed-off-by: Denis Kenzior <denkenz@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-10-26 09:30:46 +01:00
David Howells 3c58b2362b KEYS: Implement PKCS#8 RSA Private Key parser [ver #2]
Implement PKCS#8 RSA Private Key format [RFC 5208] parser for the
asymmetric key type.  For the moment, this will only support unencrypted
DER blobs.  PEM and decryption can be added later.

PKCS#8 keys can be loaded like this:

	openssl pkcs8 -in private_key.pem -topk8 -nocrypt -outform DER | \
	  keyctl padd asymmetric foo @s

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>
2018-10-26 09:30:46 +01:00
David Howells c08fed7371 KEYS: Implement encrypt, decrypt and sign for software asymmetric key [ver #2]
Implement the encrypt, decrypt and sign operations for the software
asymmetric key subtype.  This mostly involves offloading the call to the
crypto layer.

Note that the decrypt and sign operations require a private key to be
supplied.  Encrypt (and also verify) will work with either a public or a
private key.  A public key can be supplied with an X.509 certificate and a
private key can be supplied using a PKCS#8 blob:

	# j=`openssl pkcs8 -in ~/pkcs7/firmwarekey2.priv -topk8 -nocrypt -outform DER | keyctl padd asymmetric foo @s`
	# keyctl pkey_query $j - enc=pkcs1
	key_size=4096
	max_data_size=512
	max_sig_size=512
	max_enc_size=512
	max_dec_size=512
	encrypt=y
	decrypt=y
	sign=y
	verify=y
	# keyctl pkey_encrypt $j 0 data enc=pkcs1 >/tmp/enc
	# keyctl pkey_decrypt $j 0 /tmp/enc enc=pkcs1 >/tmp/dec
	# cmp data /tmp/dec
	# keyctl pkey_sign $j 0 data enc=pkcs1 hash=sha1 >/tmp/sig
	# keyctl pkey_verify $j 0 data /tmp/sig enc=pkcs1 hash=sha1
	#

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>
2018-10-26 09:30:46 +01:00
David Howells f7c4e06e06 KEYS: Allow the public_key struct to hold a private key [ver #2]
Put a flag in the public_key struct to indicate if the structure is holding
a private key.  The private key must be held ASN.1 encoded in the format
specified in RFC 3447 A.1.2.  This is the form required by crypto/rsa.c.

The software encryption subtype's verification and query functions then
need to select the appropriate crypto function to set the key.

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>
2018-10-26 09:30:46 +01:00
David Howells 82f94f2447 KEYS: Provide software public key query function [ver #2]
Provide a query function for the software public key implementation.  This
permits information about such a key to be obtained using
query_asymmetric_key() or KEYCTL_PKEY_QUERY.

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>
2018-10-26 09:30:46 +01:00
David Howells 0398849077 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>
2018-10-26 09:30:46 +01:00
David Howells 5a30771832 KEYS: Provide missing asymmetric key subops for new key type ops [ver #2]
Provide the missing asymmetric key subops for new key type ops.  This
include query, encrypt, decrypt and create signature.  Verify signature
already exists.  Also provided are accessor functions for this:

	int query_asymmetric_key(const struct key *key,
				 struct kernel_pkey_query *info);

	int encrypt_blob(struct kernel_pkey_params *params,
			 const void *data, void *enc);
	int decrypt_blob(struct kernel_pkey_params *params,
			 const void *enc, void *data);
	int create_signature(struct kernel_pkey_params *params,
			     const void *data, void *enc);

The public_key_signature struct gains an encoding field to carry the
encoding for verify_signature().

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>
2018-10-26 09:30:46 +01:00
Yannik Sembritzki 817aef2600 Replace magic for trusting the secondary keyring with #define
Replace the use of a magic number that indicates that verify_*_signature()
should use the secondary keyring with a symbol.

Signed-off-by: Yannik Sembritzki <yannik@sembritzki.me>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-16 09:57:20 -07:00
Maciej S. Szmigiero b65c32ec5a X.509: unpack RSA signatureValue field from BIT STRING
The signatureValue field of a X.509 certificate is encoded as a BIT STRING.
For RSA signatures this BIT STRING is of so-called primitive subtype, which
contains a u8 prefix indicating a count of unused bits in the encoding.

We have to strip this prefix from signature data, just as we already do for
key data in x509_extract_key_data() function.

This wasn't noticed earlier because this prefix byte is zero for RSA key
sizes divisible by 8. Since BIT STRING is a big-endian encoding adding zero
prefixes has no bearing on its value.

The signature length, however was incorrect, which is a problem for RSA
implementations that need it to be exactly correct (like AMD CCP).

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Fixes: c26fd69fa0 ("X.509: Add a crypto key parser for binary (DER) X.509 certificates")
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.morris@microsoft.com>
2018-06-25 12:17:08 -07:00
Mauro Carvalho Chehab 5fb94e9ca3 docs: Fix some broken references
As we move stuff around, some doc references are broken. Fix some of
them via this script:
	./scripts/documentation-file-ref-check --fix

Manually checked if the produced result is valid, removing a few
false-positives.

Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Coly Li <colyli@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>
2018-06-15 18:10:01 -03:00
Masahiro Yamada 4fa8bc949d 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>
2018-04-07 19:04:02 +09:00
Masahiro Yamada 3ca3273eaa kbuild: clean up *-asn1.[ch] patterns from top-level Makefile
Clean up these patterns from the top Makefile to omit 'clean-files'
in each Makefile.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-04-07 19:04:02 +09:00
Masahiro Yamada 9ce285cfe3 .gitignore: move *-asn1.[ch] patterns to the top-level .gitignore
These are common patterns where source files are parsed by the
asn1_compiler.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-04-07 19:04:02 +09:00
Eric Biggers 4b34968e77 X.509: fix NULL dereference when restricting key with unsupported_sig
The asymmetric key type allows an X.509 certificate to be added even if
its signature's hash algorithm is not available in the crypto API.  In
that case 'payload.data[asym_auth]' will be NULL.  But the key
restriction code failed to check for this case before trying to use the
signature, resulting in a NULL pointer dereference in
key_or_keyring_common() or in restrict_link_by_signature().

Fix this by returning -ENOPKG when the signature is unsupported.

Reproducer when all the CONFIG_CRYPTO_SHA512* options are disabled and
keyctl has support for the 'restrict_keyring' command:

    keyctl new_session
    keyctl restrict_keyring @s asymmetric builtin_trusted
    openssl req -new -sha512 -x509 -batch -nodes -outform der \
        | keyctl padd asymmetric desc @s

Fixes: a511e1af8b ("KEYS: Move the point of trust determination to __key_link()")
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:34 +00:00
Eric Biggers 437499eea4 X.509: fix BUG_ON() when hash algorithm is unsupported
The X.509 parser mishandles the case where the certificate's signature's
hash algorithm is not available in the crypto API.  In this case,
x509_get_sig_params() doesn't allocate the cert->sig->digest buffer;
this part seems to be intentional.  However,
public_key_verify_signature() is still called via
x509_check_for_self_signed(), which triggers the 'BUG_ON(!sig->digest)'.

Fix this by making public_key_verify_signature() return -ENOPKG if the
hash buffer has not been allocated.

Reproducer when all the CONFIG_CRYPTO_SHA512* options are disabled:

    openssl req -new -sha512 -x509 -batch -nodes -outform der \
        | keyctl padd asymmetric desc @s

Fixes: 6c2dc5ae4a ("X.509: Extract signature digest and make self-signed cert checks earlier")
Reported-by: Paolo Valente <paolo.valente@linaro.org>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:33 +00:00
Eric Biggers 6459ae3866 PKCS#7: fix direct verification of SignerInfo signature
If none of the certificates in a SignerInfo's certificate chain match a
trusted key, nor is the last certificate signed by a trusted key, then
pkcs7_validate_trust_one() tries to check whether the SignerInfo's
signature was made directly by a trusted key.  But, it actually fails to
set the 'sig' variable correctly, so it actually verifies the last
signature seen.  That will only be the SignerInfo's signature if the
certificate chain is empty; otherwise it will actually be the last
certificate's signature.

This is not by itself a security problem, since verifying any of the
certificates in the chain should be sufficient to verify the SignerInfo.
Still, it's not working as intended so it should be fixed.

Fix it by setting 'sig' correctly for the direct verification case.

Fixes: 757932e6da ("PKCS#7: Handle PKCS#7 messages that contain no X.509 certs")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:33 +00:00
Eric Biggers 29f4a67c17 PKCS#7: fix certificate blacklisting
If there is a blacklisted certificate in a SignerInfo's certificate
chain, then pkcs7_verify_sig_chain() sets sinfo->blacklisted and returns
0.  But, pkcs7_verify() fails to handle this case appropriately, as it
actually continues on to the line 'actual_ret = 0;', indicating that the
SignerInfo has passed verification.  Consequently, PKCS#7 signature
verification ignores the certificate blacklist.

Fix this by not considering blacklisted SignerInfos to have passed
verification.

Also fix the function comment with regards to when 0 is returned.

Fixes: 03bb79315d ("PKCS#7: Handle blacklisted certificates")
Cc: <stable@vger.kernel.org> # v4.12+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:33 +00:00
Eric Biggers 971b42c038 PKCS#7: fix certificate chain verification
When pkcs7_verify_sig_chain() is building the certificate chain for a
SignerInfo using the certificates in the PKCS#7 message, it is passing
the wrong arguments to public_key_verify_signature().  Consequently,
when the next certificate is supposed to be used to verify the previous
certificate, the next certificate is actually used to verify itself.

An attacker can use this bug to create a bogus certificate chain that
has no cryptographic relationship between the beginning and end.

Fortunately I couldn't quite find a way to use this to bypass the
overall signature verification, though it comes very close.  Here's the
reasoning: due to the bug, every certificate in the chain beyond the
first actually has to be self-signed (where "self-signed" here refers to
the actual key and signature; an attacker might still manipulate the
certificate fields such that the self_signed flag doesn't actually get
set, and thus the chain doesn't end immediately).  But to pass trust
validation (pkcs7_validate_trust()), either the SignerInfo or one of the
certificates has to actually be signed by a trusted key.  Since only
self-signed certificates can be added to the chain, the only way for an
attacker to introduce a trusted signature is to include a self-signed
trusted certificate.

But, when pkcs7_validate_trust_one() reaches that certificate, instead
of trying to verify the signature on that certificate, it will actually
look up the corresponding trusted key, which will succeed, and then try
to verify the *previous* certificate, which will fail.  Thus, disaster
is narrowly averted (as far as I could tell).

Fixes: 6c2dc5ae4a ("X.509: Extract signature digest and make self-signed cert checks earlier")
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2018-02-22 14:38:33 +00:00
Eric Biggers 54c1fb39fe X.509: fix comparisons of ->pkey_algo
->pkey_algo used to be an enum, but was changed to a string by commit
4e8ae72a75 ("X.509: Make algo identifiers text instead of enum").  But
two comparisons were not updated.  Fix them to use strcmp().

This bug broke signature verification in certain configurations,
depending on whether the string constants were deduplicated or not.

Fixes: 4e8ae72a75 ("X.509: Make algo identifiers text instead of enum")
Cc: <stable@vger.kernel.org> # v4.6+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-12-08 15:13:29 +00:00
Eric Biggers aa33003620 X.509: use crypto_shash_digest()
Use crypto_shash_digest() instead of crypto_shash_init() followed by
crypto_shash_finup().  (For simplicity only; they are equivalent.)

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-12-08 15:13:29 +00:00
Eric Biggers 72f9a07b6b KEYS: be careful with error codes in public_key_verify_signature()
In public_key_verify_signature(), if akcipher_request_alloc() fails, we
return -ENOMEM.  But that error code was set 25 lines above, and by
accident someone could easily insert new code in between that assigns to
'ret', which would introduce a signature verification bypass.  Make the
code clearer by moving the -ENOMEM down to where it is used.

Additionally, the callers of public_key_verify_signature() only consider
a negative return value to be an error.  This means that if any positive
return value is accidentally introduced deeper in the call stack (e.g.
'return EBADMSG' instead of 'return -EBADMSG' somewhere in RSA),
signature verification will be bypassed.  Make things more robust by
having public_key_verify_signature() warn about positive errors and
translate them into -EINVAL.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-12-08 15:13:29 +00:00
Eric Biggers a80745a6de pkcs7: use crypto_shash_digest()
Use crypto_shash_digest() instead of crypto_shash_init() followed by
crypto_shash_finup().  (For simplicity only; they are equivalent.)

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2017-12-08 15:13:28 +00:00
Eric Biggers 7204eb8590 pkcs7: fix check for self-signed certificate
pkcs7_validate_trust_one() used 'x509->next == x509' to identify a
self-signed certificate.  That's wrong; ->next is simply the link in the
linked list of certificates in the PKCS#7 message.  It should be
checking ->signer instead.  Fix it.

Fortunately this didn't actually matter because when we re-visited
'x509' on the next iteration via 'x509->signer', it was already seen and
not verified, so we returned -ENOKEY anyway.

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>
2017-12-08 15:13:28 +00:00