Pull crypto fix from Herbert Xu:
"This fixes a bug in the algif_hash interface that may lead to crashes
when used with certain algorithms such as HMAC"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: algif_hash - Only export and import on sockets with data
Pull security subsystem update from James Morris:
"This is mostly maintenance updates across the subsystem, with a
notable update for TPM 2.0, and addition of Jarkko Sakkinen as a
maintainer of that"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (40 commits)
apparmor: clarify CRYPTO dependency
selinux: Use a kmem_cache for allocation struct file_security_struct
selinux: ioctl_has_perm should be static
selinux: use sprintf return value
selinux: use kstrdup() in security_get_bools()
selinux: use kmemdup in security_sid_to_context_core()
selinux: remove pointless cast in selinux_inode_setsecurity()
selinux: introduce security_context_str_to_sid
selinux: do not check open perm on ftruncate call
selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default
KEYS: Merge the type-specific data with the payload data
KEYS: Provide a script to extract a module signature
KEYS: Provide a script to extract the sys cert list from a vmlinux file
keys: Be more consistent in selection of union members used
certs: add .gitignore to stop git nagging about x509_certificate_list
KEYS: use kvfree() in add_key
Smack: limited capability for changing process label
TPM: remove unnecessary little endian conversion
vTPM: support little endian guests
char: Drop owner assignment from i2c_driver
...
Pull crypto update from Herbert Xu:
"API:
- Add support for cipher output IVs in testmgr
- Add missing crypto_ahash_blocksize helper
- Mark authenc and des ciphers as not allowed under FIPS.
Algorithms:
- Add CRC support to 842 compression
- Add keywrap algorithm
- A number of changes to the akcipher interface:
+ Separate functions for setting public/private keys.
+ Use SG lists.
Drivers:
- Add Intel SHA Extension optimised SHA1 and SHA256
- Use dma_map_sg instead of custom functions in crypto drivers
- Add support for STM32 RNG
- Add support for ST RNG
- Add Device Tree support to exynos RNG driver
- Add support for mxs-dcp crypto device on MX6SL
- Add xts(aes) support to caam
- Add ctr(aes) and xts(aes) support to qat
- A large set of fixes from Russell King for the marvell/cesa driver"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (115 commits)
crypto: asymmetric_keys - Fix unaligned access in x509_get_sig_params()
crypto: akcipher - Don't #include crypto/public_key.h as the contents aren't used
hwrng: exynos - Add Device Tree support
hwrng: exynos - Fix missing configuration after suspend to RAM
hwrng: exynos - Add timeout for waiting on init done
dt-bindings: rng: Describe Exynos4 PRNG bindings
crypto: marvell/cesa - use __le32 for hardware descriptors
crypto: marvell/cesa - fix missing cpu_to_le32() in mv_cesa_dma_add_op()
crypto: marvell/cesa - use memcpy_fromio()/memcpy_toio()
crypto: marvell/cesa - use gfp_t for gfp flags
crypto: marvell/cesa - use dma_addr_t for cur_dma
crypto: marvell/cesa - use readl_relaxed()/writel_relaxed()
crypto: caam - fix indentation of close braces
crypto: caam - only export the state we really need to export
crypto: caam - fix non-block aligned hash calculation
crypto: caam - avoid needlessly saving and restoring caam_hash_ctx
crypto: caam - print errno code when hash registration fails
crypto: marvell/cesa - fix memory leak
crypto: marvell/cesa - fix first-fragment handling in mv_cesa_ahash_dma_last_req()
crypto: marvell/cesa - rearrange handling for sw padded hashes
...
The hash_accept call fails to work on sockets that have not received
any data. For some algorithm implementations it may cause crashes.
This patch fixes this by ensuring that we only export and import on
sockets that have received data.
Cc: stable@vger.kernel.org
Reported-by: Harsh Jain <harshjain.prof@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Stephan Mueller <smueller@chronox.de>
Pull crypto fix from Herbert Xu:
"This fixes a problem in the Crypto API that may cause spurious errors
when signals are received by the process that made the orignal system
call into the kernel"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: api - Only abort operations on fatal signal
x509_get_sig_params() has the same code pattern as the one in
pkcs7_verify() that is fixed by commit 62f57d05e2 ("crypto: pkcs7 - Fix
unaligned access in pkcs7_verify()") so apply a similar fix here: make
sure that desc is pointing at an algined value past the digest_size,
and take alignment values into consideration when doing kzalloc()
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Don't #include crypto/public_key.h in akcipher as the contents of the
header aren't used and changes in a future patch cause it to fail to
compile if CONFIG_KEYS=n.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently a number of Crypto API operations may fail when a signal
occurs. This causes nasty problems as the caller of those operations
are often not in a good position to restart the operation.
In fact there is currently no need for those operations to be
interrupted by user signals at all. All we need is for them to
be killable.
This patch replaces the relevant calls of signal_pending with
fatal_signal_pending, and wait_for_completion_interruptible with
wait_for_completion_killable, respectively.
Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The testmanager code for symmetric ciphers is extended to allow
verification of the IV after a cipher operation.
In addition, test vectors for kw(aes) for encryption and decryption are
added.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Hook keywrap source code into Kconfig and Makefile
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch implements the AES key wrapping as specified in
NIST SP800-38F and RFC3394.
The implementation covers key wrapping without padding.
IV handling: The caller does not provide an IV for encryption,
but must obtain the IV after encryption which would serve as the first
semblock in the ciphertext structure defined by SP800-38F. Conversely,
for decryption, the caller must provide the first semiblock of the data
as the IV and the following blocks as ciphertext.
The key wrapping is an authenticated decryption operation. The caller
will receive EBADMSG during decryption if the authentication failed.
Albeit the standards define the key wrapping for AES only, the template
can be used with any other block cipher that has a block size of 16
bytes. During initialization of the template, that condition is checked.
Any cipher not having a block size of 16 bytes will cause the
initialization to fail.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The crypto drivers are supposed to update the IV passed to the crypto
request before calling the completion callback.
Test for the IV value before considering the test as successful.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
On sparc, we see unaligned access messages on each modprobe[-r]:
Kernel unaligned access at TPC[6ad9b4] pkcs7_verify [..]
Kernel unaligned access at TPC[6a5484] crypto_shash_finup [..]
Kernel unaligned access at TPC[6a5390] crypto_shash_update [..]
Kernel unaligned access at TPC[10150308] sha1_sparc64_update [..]
Kernel unaligned access at TPC[101501ac] __sha1_sparc64_update [..]
These ware triggered by mod_verify_sig() invocations of pkcs_verify(), and
are are being caused by an unaligned desc at (sha1, digest_size is 0x14)
desc = digest + digest_size;
To fix this, pkcs7_verify needs to make sure that desc is pointing
at an aligned value past the digest_size, and kzalloc appropriately,
taking alignment values into consideration.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The clocksource does not provide clocksource_register() function since
f893598 commit (clocksource: Mostly kill clocksource_register()), so
let's remove unnecessary information about this function from a comment.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Setkey function has been split into set_priv_key and set_pub_key.
Akcipher requests takes sgl for src and dst instead of void *.
Users of the API i.e. two existing RSA implementation and
test mgr code have been updated accordingly.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- Fix AVX detection to prevent use of non-existent AESNI.
- Some SPARC ciphers did not set their IV size which may lead to
memory corruption"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: ahash - ensure statesize is non-zero
crypto: camellia_aesni_avx - Fix CPU feature checks
crypto: sparc - initialize blkcipher.ivsize
Unlike shash algorithms, ahash drivers must implement export
and import as their descriptors may contain hardware state and
cannot be exported as is. Unfortunately some ahash drivers did
not provide them and end up causing crashes with algif_hash.
This patch adds a check to prevent these drivers from registering
ahash algorithms until they are fixed.
Cc: stable@vger.kernel.org
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixes the following sparse warnings:
crypto/skcipher.c:94:5:
warning: symbol 'crypto_init_skcipher_ops_blkcipher'
was not declared. Should it be static?
crypto/skcipher.c:185:5:
warning: symbol 'crypto_init_skcipher_ops_ablkcipher'
was not declared. Should it be static?
Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
No authenc() ciphers are FIPS approved, nor is ecb(des).
After the end of 2015, ansi_cprng will also be non-approved.
Signed-off-by: John Haxby <john.haxby@oracle.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Don't strip leading zeros from the crypto key ID when using it to construct
the struct key description as the signature in kernels up to and including
4.2 matched this aspect of the key. This means that 1 in 256 keys won't
actually match if their key ID begins with 00.
The key ID is stored in the module signature as binary and so must be
converted to text in order to invoke request_key() - but it isn't stripped
at this point.
Something like this is likely to be observed in dmesg when the key is loaded:
[ 1.572423] Loaded X.509 cert 'Build time autogenerated kernel
key: 62a7c3d2da278be024da4af8652c071f3fea33'
followed by this when we try and use it:
[ 1.646153] Request for unknown module key 'Build time autogenerated
kernel key: 0062a7c3d2da278be024da4af8652c071f3fea33' err -11
The 'Loaded' line should show an extra '00' on the front of the hex string.
This problem should not affect 4.3-rc1 and onwards because there the key
should be matched on one of its auxiliary identities rather than the key
struct's description string.
Reported-by: Arjan van de Ven <arjan@linux.intel.com>
Reported-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: David Howells <dhowells@redhat.com>
This patch provides the configuration and build support to
include and build the optimized SHA1 and SHA256 update transforms
for the kernel's crypto library.
Originally-by: Chandramouli Narayanan <mouli_7982@yahoo.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
hour, min and sec are unsigned int and they can never be less than zero.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The output buffer in test_ahash_speed will point to an address located
within the tcrypt module image.
This causes problems when trying to DMA map the buffer.
For e.g. on ARM-based LS1021A, a page fault occurs within the
DMA API when trying to access the struct page returned by
virt_to_page(output):
insmod tcrypt.ko mode=403
testing speed of async sha1 (sha1-caam)
test 0 ( 16 byte blocks, 16 bytes per update, 1 updates):
Unable to handle kernel paging request at virtual address f07e9080
pgd = e58d0e00
[f07e9080] *pgd=80000080007003, *pmd=00000000
Internal error: Oops: 206 [#1] SMP THUMB2
Modules linked in: tcrypt(+)
CPU: 1 PID: 1119 Comm: insmod Not tainted 4.2.0-rc1-256134-gbf433416e675 #1
Hardware name: Freescale LS1021A
task: ea063900 ti: e5a34000 task.ti: e5a34000
PC is at dma_cache_maint_page+0x38/0xd0
LR is at __dma_page_cpu_to_dev+0x15/0x64
pc : [<800155a0>] lr : [<8001564d>] psr: 000f0033
sp : e5a35ca0 ip : 8063df00 fp : f07e9080
r10: 00000cd0 r9 : 8063df00 r8 : 805a2f04
r7 : 0017f804 r6 : 00000002 r5 : ee7f9000 r4 : 00000014
r3 : 80612d40 r2 : 01ff0080 r1 : 00000380 r0 : ee7f9000
Flags: nzcv IRQs on FIQs on Mode SVC_32 ISA Thumb Segment user
Control: 70c5387d Table: e58d0e00 DAC: 9b7ede70
Process insmod (pid: 1119, stack limit = 0xe5a34210)
Stack: (0xe5a35ca0 to 0xe5a36000)
[...]
[<800155a0>] (dma_cache_maint_page) from [<8001564d>] (__dma_page_cpu_to_dev+0x15/0x64)
[<8001564d>] (__dma_page_cpu_to_dev) from [<800156eb>] (arm_dma_map_page+0x1f/0x44)
[<800156eb>] (arm_dma_map_page) from [<802935e3>] (ahash_digest+0x35f/0x510)
[<802935e3>] (ahash_digest) from [<7f800d03>] (test_ahash_speed.constprop.6+0x24a/0x4e4 [tcrypt])
[<7f800d03>] (test_ahash_speed.constprop.6 [tcrypt]) from [<7f802fd5>] (do_test+0x1898/0x2058 [tcrypt])
[<7f802fd5>] (do_test [tcrypt]) from [<7f80802f>] (tcrypt_mod_init+0x2e/0x63 [tcrypt])
[<7f80802f>] (tcrypt_mod_init [tcrypt]) from [<80009517>] (do_one_initcall+0xb3/0x134)
[<80009517>] (do_one_initcall) from [<80351ec7>] (do_init_module+0x3b/0x13c)
[<80351ec7>] (do_init_module) from [<8005cc3f>] (load_module+0x97b/0x9dc)
[<8005cc3f>] (load_module) from [<8005cd8d>] (SyS_finit_module+0x35/0x3e)
[<8005cd8d>] (SyS_finit_module) from [<8000d101>] (ret_fast_syscall+0x1/0x4c)
Code: 1aba 0152 eb00 0b02 (5882) 0f92
addr2line -f -i -e vmlinux 800155a0
page_zonenum
include/linux/mm.h:728
page_zone
include/linux/mm.h:881
dma_cache_maint_page
arch/arm/mm/dma-mapping.c:822
Signed-off-by: Horia Geant? <horia.geanta@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto fixes from Herbert Xu:
"This fixes the following issues:
- The selftest overreads the IV test vector.
- Fix potential infinite loop in sunxi-ss driver.
- Fix powerpc build failure when VMX is set without VSX"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: testmgr - don't copy from source IV too much
crypto: sunxi-ss - Fix a possible driver hang with ciphers
crypto: vmx - VMX crypto should depend on CONFIG_VSX
While the destination buffer 'iv' is MAX_IVLEN size,
the source 'template[i].iv' could be smaller, thus
memcpy may read read invalid memory.
Use crypto_skcipher_ivsize() to get real ivsize
and pass it to memcpy.
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull security subsystem updates from James Morris:
"Highlights:
- PKCS#7 support added to support signed kexec, also utilized for
module signing. See comments in 3f1e1bea.
** NOTE: this requires linking against the OpenSSL library, which
must be installed, e.g. the openssl-devel on Fedora **
- Smack
- add IPv6 host labeling; ignore labels on kernel threads
- support smack labeling mounts which use binary mount data
- SELinux:
- add ioctl whitelisting (see
http://kernsec.org/files/lss2015/vanderstoep.pdf)
- fix mprotect PROT_EXEC regression caused by mm change
- Seccomp:
- add ptrace options for suspend/resume"
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (57 commits)
PKCS#7: Add OIDs for sha224, sha284 and sha512 hash algos and use them
Documentation/Changes: Now need OpenSSL devel packages for module signing
scripts: add extract-cert and sign-file to .gitignore
modsign: Handle signing key in source tree
modsign: Use if_changed rule for extracting cert from module signing key
Move certificate handling to its own directory
sign-file: Fix warning about BIO_reset() return value
PKCS#7: Add MODULE_LICENSE() to test module
Smack - Fix build error with bringup unconfigured
sign-file: Document dependency on OpenSSL devel libraries
PKCS#7: Appropriately restrict authenticated attributes and content type
KEYS: Add a name for PKEY_ID_PKCS7
PKCS#7: Improve and export the X.509 ASN.1 time object decoder
modsign: Use extract-cert to process CONFIG_SYSTEM_TRUSTED_KEYS
extract-cert: Cope with multiple X.509 certificates in a single file
sign-file: Generate CMS message as signature instead of PKCS#7
PKCS#7: Support CMS messages also [RFC5652]
X.509: Change recorded SKID & AKID to not include Subject or Issuer
PKCS#7: Check content type and versions
MAINTAINERS: The keyrings mailing list has moved
...
Pull SG updates from Jens Axboe:
"This contains a set of scatter-gather related changes/fixes for 4.3:
- Add support for limited chaining of sg tables even for
architectures that do not set ARCH_HAS_SG_CHAIN. From Christoph.
- Add sg chain support to target_rd. From Christoph.
- Fixup open coded sg->page_link in crypto/omap-sham. From
Christoph.
- Fixup open coded crypto ->page_link manipulation. From Dan.
- Also from Dan, automated fixup of manual sg_unmark_end()
manipulations.
- Also from Dan, automated fixup of open coded sg_phys()
implementations.
- From Robert Jarzmik, addition of an sg table splitting helper that
drivers can use"
* 'for-4.3/sg' of git://git.kernel.dk/linux-block:
lib: scatterlist: add sg splitting function
scatterlist: use sg_phys()
crypto/omap-sham: remove an open coded access to ->page_link
scatterlist: remove open coded sg_unmark_end instances
crypto: replace scatterwalk_sg_chain with sg_chain
target/rd: always chain S/G list
scatterlist: allow limited chaining without ARCH_HAS_SG_CHAIN
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>
The tsgl scatterlist must be re-initialized after each
operation. Otherwise the sticky bits in the page_link will corrupt the
list with pre-mature termination or false chaining.
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch introduces the crypto skcipher interface which aims
to replace both blkcipher and ablkcipher.
It's very similar to the existing ablkcipher interface. The
main difference is the removal of the givcrypt interface. In
order to make the transition easier for blkcipher users, there
is a helper SKCIPHER_REQUEST_ON_STACK which can be used to place
a request on the stack for synchronous transforms.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
CMAC is an approved cipher in FIPS 140-2. The patch allows the use
of CMAC with TDES and AES in FIPS mode.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
[hch: split from a larger patch by Dan]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jens Axboe <axboe@fb.com>
This patch adds a missing tristate statement to Kconfig for the
new CRYPTO_NULL2 option.
Fixes: 149a39717d ("crypto: aead - Add type-safe geniv init/exit helpers")
Reported-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The Kconfig option NULL2 has been added as CRYPTO_MANAGER now
depends indirectly on NULL2. However, the Makefile was not updated
to use the new option, resulting in potential build failures when
only NULL2 is enabled.
Fixes: 149a39717d ("crypto: aead - Add type-safe geniv init/exit helpers")
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that the AEAD conversion is complete we can rip out the old
AEAD interafce and associated code.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pretty soon the crypto_aead encrypt/decrypt hooks will disappear
as they are now always identical to those in struct aead_alg.
This patch replaces the references to these hooks with the ones
from aead_alg instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds the helpers aead_init_geniv and aead_exit_geniv
which are type-safe and intended the replace the existing geniv
init/exit helpers.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that we no longer have any legacy AEAD implementations the
compatibility code path can no longer be triggered. This patch
removes it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that we no longer have any legacy AEAD implementations the
compatibility code path can no longer be triggered. This patch
removes it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As IV generators are now standalone AEAD transforms, we no longer
need to use the crypto_lookup_aead call.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Move certificate handling out of the kernel/ directory and into a certs/
directory to get all the weird stuff in one place and move the generated
signing keys into this directory.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: David Woodhouse <David.Woodhouse@intel.com>
Add a MODULE_LICENSE() line to the PKCS#7 test key module to fix this
warning:
WARNING: modpost: missing MODULE_LICENSE() in
crypto/asymmetric_keys/pkcs7_test_key.o
Whilst we're at it, also add a module description.
Reported-by: James Morris <jmorris@namei.org>
Signed-off-by: David Howells <dhowells@redhat.com>
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>
Linus Torvalds