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mirror of https://git.code.sf.net/p/linux-ima/ima-evm-utils synced 2025-04-28 06:33:36 +02:00

33 Commits

Author SHA1 Message Date
Mimi Zohar
c1635add22 Disable use of OpenSSL "engine" support
OpenSSL v3 "engine" support is deprecated and replaced with "providers".
Engine support will continue to work for a while, but results in
deprecated declaration and other messages.  One option is simply to hide
them ("-Wno-deprecated-declarations").  The other alternative is to
conditionally build ima-evm-utils without OpenSSL engine support and
without disabling deprecated declarations.

Based on "--disable-engine" or "--enable-engine=no" configuration
option, disable OpenSSL "engine" support.

As suggested by Vitaly,
- verify ENGINE_init symbol is defined in libcrypto
- disable engine support if either OPENSSL_NO_DYNAMIC_ENGINE or
OPENSSL_NO_ENGINE variables are defined

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-11-13 16:56:18 -05:00
Mimi Zohar
fc46af121e Sign an fs-verity file digest
Sign fs-verity file digests provided in the format as produced by
"fsverity digest".  The output is of the same format as the input,
but with the file signature appended.  Use setfattr to write the
signature as security.ima xattr.

fsverity digest format: <algo>:<hash> <pathname>
output format: <algo>:<hash> <pathname> <signature>

Instead of directly signing the fsverity hash, to disambiguate the
original IMA signatures from the fs-verity signatures stored in the
security.ima xattr a new signature format version 3 (sigv3) was
defined as the hash of the xattr type (enum evm_ima_xattr_type),
the hash algorithm (enum hash_algo), and the hash.

Example:
fsverity digest <pathname> | evmctl sign_hash --veritysig \
 --key <pem encoded private key>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2022-08-29 17:55:46 -04:00
Bruno Meneguele
3328f6efed make SHA-256 the default hash algorithm
The SHA-1 algorithm is considered a weak hash algorithm and there has been
some movement within certain distros to drop its support completely or at
least drop it from the default behavior. ima-evm-utils uses it as the
default algorithm in case the user doesn't explicitly ask for another
through the --with-default-hash configuration time option or --hashalgo/-a
runtime option. With that, make SHA-256 the default hash algorithm instead.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-09-13 19:20:17 -04:00
Bruno Meneguele
80bb310152 set default hash algorithm in configuration time
The default hash algorithm for evmctl is today hardcoded in the libimaevm.c
file. To facilitate package maintainers across different distributions to
set their own default hash algorithm, this patch adds the
--with-default-hash=<algo> option to the configuration script.

The chosen algorithm will then be checked by its available in the kernel,
otherwise IMA won't be able to verify files hashed by the user. For that,
the kernel header hash_info.h used as the source of supported hashes. In
case the hash_info.h header is not present, the configuration script warns
about it, but uses whatever the user specified in the option.

Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-09-13 19:19:31 -04:00
Stefan Berger
1de1e3c8ce evmctl: Define and use an ENGINE field in libimaevm_params
Extend the global libimaevm_params structure with an ENGINE field 'eng'
and use it in place of the local ENGINE variable in main().

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-09-13 18:39:38 -04:00
Vitaly Chikunov
0e7a00e26b Allow manual setting keyid from a cert file
Allow user to specify `--keyid-from-cert cert.pem' to extract keyid from
SKID of the certificate file. PEM or DER format is auto-detected.

This commit creates ABI change for libimaevm, due to adding new function
ima_read_keyid(). Newer clients cannot work with older libimaevm.
Together with previous commit it creates backward-incompatible ABI
change, thus soname should be incremented on release.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-07-16 17:10:33 -04:00
Vitaly Chikunov
51b694bfea Allow manual setting keyid for signing
Allow user to set signature's keyid using `--keyid' option. Keyid should
correspond to SKID in certificate, when keyid is calculated using SHA-1
in libimaevm it may mismatch keyid extracted by the kernel from SKID of
certificate (the way public key is presented to the kernel), thus making
signatures not verifiable. This may happen when certificate is using non
SHA-1 SKID (see rfc7093) or just 'unique number' (see rfc5280 4.2.1.2).
As a last resort user may specify arbitrary keyid using the new option.

This commit creates ABI change for libimaevm, because of adding
additional parameter to imaevm_params - newer libimaevm cannot work
with older clients.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reported-by: Elvira Khabirova <lineprinter0@gmail.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-07-16 17:10:33 -04:00
Stephen Smalley
8e2738dd44 extend ima_measurement --pcrs option to support per-bank pcr files
Extend the ima_measurement --pcrs option to support per-bank pcr files.
The extended syntax is "--pcrs algorithm,pathname".  If no algorithm
is specified, it defaults to sha1 as before.  Multiple --pcrs options
are now supported, one per bank of PCRs. The file format remains
unchanged.  If --pcrs is specified, only try to read PCRs from the
specified file(s); do not fall back to trying to read from sysfs
or the TPM itself in this case since the user requested use of
the files.

Create per-bank pcr files, depends on "tpm: add sysfs exports for all
banks of PCR registers" kernel patch:
$ cat tpm2pcrread.sh
for alg in sha1 sha256
do
  rm -f pcr-$alg
  pcr=0;
  while [ $pcr -lt 24 ];
  do
    printf "PCR-%02d: " $pcr >> pcr-$alg;
    cat /sys/class/tpm/tpm0/pcr-$alg/$pcr >> pcr-$alg;
    pcr=$[$pcr+1];
  done
done
$ sh ./tpm2pcrread.sh

Pass only the sha1 PCRs to evmctl defaulting to sha1:
$ sudo evmctl ima_measurement --pcrs pcr-sha1 /sys/kernel/security/integrity/ima/binary_runtime_measurements

Pass only the sha1 PCRs to evmctl with explicit selection of sha1:
$ sudo evmctl ima_measurement --pcrs sha1,pcr-sha1 /sys/kernel/security/integrity/ima/binary_runtime_measurements

Pass both sha1 and sha256 PCRs to evmctl:
$ sudo evmctl ima_measurement --pcrs sha1,pcr-sha1 --pcrs sha256,pcr-sha256 /sys/kernel/security/integrity/ima/binary_runtime_measurements

Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[zohar@linux.ibm.com: although support for exporting TPM 2.0 PCRs has
not yet been upstreamed, add support for the file format anyway.]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-08-04 08:17:32 -04:00
Petr Vorel
7f9a59c6c6 Fix missing {u,g}id_t typedef on musl
Fixes: 273701a ("evmctl - IMA/EVM control tool")

Signed-off-by: Petr Vorel <petr.vorel@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-22 17:20:14 -04:00
Vitaly Chikunov
cf1b8fda8d ima-evm-utils: Allow EVM verify to determine hash algo
Previously for EVM verify you should specify `--hashalgo' option while
for IMA ima_verify you didn't.

Allow EVM verify to determine hash algo from signature.

Also, this makes two previously static functions to become exportable
and renamed:

  get_hash_algo_from_sig -> imaevm_hash_algo_from_sig
  get_hash_algo_by_id    -> imaevm_hash_algo_by_id

This is needed because EVM hash is calculated (in calc_evm_hash) outside
of library.

imaevm_hash_algo_by_id() will now return NULL if algo is not found.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-30 13:32:28 -04:00
Vitaly Chikunov
c317d4618f ima-evm-utils: Namespace some too generic object names
Prefix `dump', `do_dump', and `params' with `imaevm_' to avoid colliding
with other global symbols.
Also, rename `libevm_' to `libimaevm_`, only used with `params'.
Additionally, rename `dump' into `hexdump'.
Finally, rename `get_hash_algo' to `imaevm_get_hash_algo' as suggested by
Mimi Zohar.

Lines that became too long are split, indent corrected. No code changes.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Bruno E. O. Meneguele <bmeneg@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-25 12:14:21 -04:00
Vitaly Chikunov
3359563dbe ima-evm-utils: Remove indirect call to subfunctions in verify_hash
This is more human understandable and also will improve handling of
the sources by cscope.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-18 21:09:32 -04:00
Vitaly Chikunov
08a51e7460 ima-evm-utils: Fix file2bin stat and fopen relations
Check stat(2) return value, use fstat(2) to avoid race between
stat() and fopen(), remove now unused get_filesize().

Fixes: CID 229889.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-16 14:14:03 -04:00
Vitaly Chikunov
28d3a1b293 ima-evm-utils: Remove RSA_ASN1_templates
RSA_ASN1_templates[] are not needed anymore, because we switched to the
generic EVP_PKEY OpenSSL API to generate v2 signatures instead of
constructing PKCS1 ourselves.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-08 10:00:06 -04:00
Vitaly Chikunov
13d4521dbf ima-evm-utils: Replace calc_keyid_v2 with calc_pkeyid_v2
Finish conversion of calc keyid v2 to EVP_PKEY API. After sign_hash_v2()
is switched to EVP_PKEY API (in previous commit), older RSA-specific
calc_keyid_v2() does not needed anymore and can be replaced with
calc_pkeyid_v2().

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-08 09:59:59 -04:00
Vitaly Chikunov
af4e3c06bb ima-evm-utils: Convert cmd_import and calc keyid v2 to EVP_PKEY API
Introduce calc_pkeyid_v2() (which accepts EVP_PKEY) to replace
calc_keyid_v2() (which accepts RSA) in the future and use it in
cmd_import().

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-08 09:59:14 -04:00
Vitaly Chikunov
71c1be47e7 ima-evm-utils: Convert read_pub_key to EVP_PKEY API
Introduce read_pub_pkey() to read keys using EVP_PKEY, and change
read_pub_key() to be wrapper for it.

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2019-07-08 09:58:49 -04:00
Vitaly Chikunov
7e2a7840a7 ima-evm-utils: Allow using Streebog hash function
This patch will allow using GOST algorithms from OpenSSL's
gost-engine[1] via config extension (which is the usual way).

[1] https://github.com/gost-engine/engine

Full usage example:

1. Install the gost-engine package for your distro, this could be
libengine-gost-openssl1.1, openssl-gost-engine, or openssl-engines.

2. Edit openssl.cnf appropriately. Reference INSTALL.md of gost-engine
for the detailed instructions.

3. Then GOST algorithms should work:

  $ cp /dev/null a
  $ openssl dgst -streebog256 a
  md_gost12_256(a)= 3f539a213e97c802cc229d474c6aa32a825a360b2a933a949fd925208d9ce1bb
  $ evmctl -v ima_hash -a streebog256 --xattr-user a
  hash: 04123f539a213e97c802cc229d474c6aa32a825a360b2a933a949fd925208d9ce1bb
  $ getfattr -d -m. -ehex a
  # file: a
  user.ima=0x04123f539a213e97c802cc229d474c6aa32a825a360b2a933a949fd925208d9ce1bb

Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-03 06:08:36 -05:00
Vitaly Chikunov
1d9c279279 ima-evm-utils: Define hash and sig buffer sizes and add asserts
To prevent hash and sig buffers size mismatch, define their maximum
sizes and add sanity checking asserts.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2018-12-03 06:08:36 -05:00
Mimi Zohar
057efc397d Include the file name in "ima_measurement" verification result
When displaying the measurement list, include the filename in the result.

Signed-of-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-02-06 07:50:01 -05:00
Mimi Zohar
6921833477 ima-evm-utils: add support for validating multiple pcrs
The IMA measurement list may contain records for different PCRs.  This
patch walks the measurement list, calculating a PCR aggregate value for
each PCR.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-01-28 10:02:18 -05:00
Mimi Zohar
1a69e42ac1 ima-evm-utils: verify the measurement list signature based on the list digest
Instead of verifying file signatures included in the measurement list,
by calculating the local file hash, verify the file signature based on the
digest contained in the measurement list.

This patch defines a new option named "--list".

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-01-28 09:57:34 -05:00
Mimi Zohar
9c79b7de72 ima-evm-utils: support verifying the measurement list using multiple keys
On a running system, different software packages might be signed by
different parties.  Support verifying signatures in the measurement
list using multiple public keys(eg.  -k "key1, key2, ...").

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2018-01-28 09:57:34 -05:00
Matthew Garrett
4928548d9d Add support for portable EVM format
Add a --portable argument that generates EVM signatures without using
the inode number and generation or fs UUID.

Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

Changelog:
- immutable and portable flags are exclusive, prevent enabling both.
2017-11-16 15:02:40 -05:00
Dmitry Kasatkin
96e55082c2 Must use 'const char*'
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
2015-07-24 22:51:39 +03:00
Mimi Zohar
6a712b3b38 Add support for passing the private key password to sign_hash()
evmctl defines the "--pass | -p" command line option for providing
the private key's password.  The password is then stored in a global
variable accessible by the sign_hash_XXXX() functions.

This patch modifies the arguments to the library sign_hash()
function to include the password, allowing callers to specify the
private key password.

Changelog:
- add library init to call OpenSSL_add_all_algorithms

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2015-07-24 22:51:27 +03:00
Dmitry Kasatkin
92033dc404 Produce immutable EVM signature
'evmctl sign -i <file>' generates immutable EVM signature.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-10-29 13:00:43 +02:00
Fionnuala Gunter
8f04d131ac Move sign hash functions to library
This patch enables package managers, such as rpm, to include IMA signatures in
packages.

To do this, sign_hash and some helper functions were moved from evmctl to
libimaevm. These functions used global variables that belong to evmctl, sigdump
and keypass. The variable sigdump is a flag that file signatures should be
printed to stdout, so the signature dump is now handled by functions that call
sign_hash. The variable keypass is a passphrase for an encrypted key, so it was
added to 'struct libevm_params'.

v2: Uses 'struct libevm_params' to minimize sign_hash parameters
v3: Export single sign_hash function that selects _v1 or _v2 internally based
on params.x509. Moved parameter checks and explicitly return -1 for failures.

Signed-off-by: Fionnuala Gunter <fin@linux.vnet.ibm.com>
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-09-11 16:50:20 +03:00
Dmitry Kasatkin
29adc34d35 Remove local ioctl definitions and use <linux/fs.h>
Use standard flags, supported by ext2/3/4

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-06-25 18:54:55 +03:00
Dmitry Kasatkin
9bc24ee556 Use defined xattr types
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-06-24 15:54:37 +03:00
Dmitry Kasatkin
2b893135be Update license text with OpenSSL exception clause
Ubuntu/Debian requires to provide OpenSSL exception clause.
This patch fixes it.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-05-02 17:19:47 +03:00
Dmitry Kasatkin
c7042472e8 Limit includes in imaevm.h
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-02-17 15:56:07 +02:00
Dmitry Kasatkin
12af148131 Rename library, header file and export it.
Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-02-17 15:56:07 +02:00