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5
.gitignore
vendored
5
.gitignore
vendored
@ -2,6 +2,8 @@
|
||||
*~
|
||||
|
||||
# Generated by autotools
|
||||
.libs
|
||||
m4
|
||||
.deps
|
||||
aclocal.m4
|
||||
autom4te.cache
|
||||
@ -20,9 +22,12 @@ compile
|
||||
libtool
|
||||
ltmain.sh
|
||||
|
||||
|
||||
# Compiled executables
|
||||
*.o
|
||||
*.a
|
||||
*.lo
|
||||
*.la
|
||||
src/evmctl
|
||||
tests/openclose
|
||||
config.h
|
||||
|
6
AUTHORS
6
AUTHORS
@ -1,2 +1,6 @@
|
||||
Dmitry Kasatkin <dmitry.kasatkin@intel.com>
|
||||
Dmitry Kasatkin <d.kasatkin@samsung.com>
|
||||
|
||||
CONTRIBUTORS:
|
||||
Vivek Goyal <vgoyal@redhat.com>
|
||||
Mimi Zohar <zohar@linux.vnet.ibm.com>
|
||||
|
||||
|
25
COPYING
25
COPYING
@ -1,8 +1,8 @@
|
||||
GNU GENERAL PUBLIC LICENSE
|
||||
Version 2, June 1991
|
||||
|
||||
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
|
||||
59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
Copyright (C) 1989, 1991 Free Software Foundation, Inc.,
|
||||
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
||||
Everyone is permitted to copy and distribute verbatim copies
|
||||
of this license document, but changing it is not allowed.
|
||||
|
||||
@ -15,7 +15,7 @@ software--to make sure the software is free for all its users. This
|
||||
General Public License applies to most of the Free Software
|
||||
Foundation's software and to any other program whose authors commit to
|
||||
using it. (Some other Free Software Foundation software is covered by
|
||||
the GNU Library General Public License instead.) You can apply it to
|
||||
the GNU Lesser General Public License instead.) You can apply it to
|
||||
your programs, too.
|
||||
|
||||
When we speak of free software, we are referring to freedom, not
|
||||
@ -55,7 +55,7 @@ patent must be licensed for everyone's free use or not licensed at all.
|
||||
|
||||
The precise terms and conditions for copying, distribution and
|
||||
modification follow.
|
||||
|
||||
|
||||
GNU GENERAL PUBLIC LICENSE
|
||||
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
|
||||
|
||||
@ -110,7 +110,7 @@ above, provided that you also meet all of these conditions:
|
||||
License. (Exception: if the Program itself is interactive but
|
||||
does not normally print such an announcement, your work based on
|
||||
the Program is not required to print an announcement.)
|
||||
|
||||
|
||||
These requirements apply to the modified work as a whole. If
|
||||
identifiable sections of that work are not derived from the Program,
|
||||
and can be reasonably considered independent and separate works in
|
||||
@ -168,7 +168,7 @@ access to copy from a designated place, then offering equivalent
|
||||
access to copy the source code from the same place counts as
|
||||
distribution of the source code, even though third parties are not
|
||||
compelled to copy the source along with the object code.
|
||||
|
||||
|
||||
4. You may not copy, modify, sublicense, or distribute the Program
|
||||
except as expressly provided under this License. Any attempt
|
||||
otherwise to copy, modify, sublicense or distribute the Program is
|
||||
@ -225,7 +225,7 @@ impose that choice.
|
||||
|
||||
This section is intended to make thoroughly clear what is believed to
|
||||
be a consequence of the rest of this License.
|
||||
|
||||
|
||||
8. If the distribution and/or use of the Program is restricted in
|
||||
certain countries either by patents or by copyrighted interfaces, the
|
||||
original copyright holder who places the Program under this License
|
||||
@ -278,7 +278,7 @@ PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
|
||||
POSSIBILITY OF SUCH DAMAGES.
|
||||
|
||||
END OF TERMS AND CONDITIONS
|
||||
|
||||
|
||||
How to Apply These Terms to Your New Programs
|
||||
|
||||
If you develop a new program, and you want it to be of the greatest
|
||||
@ -303,10 +303,9 @@ the "copyright" line and a pointer to where the full notice is found.
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with this program; if not, write to the Free Software
|
||||
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
||||
|
||||
You should have received a copy of the GNU General Public License along
|
||||
with this program; if not, write to the Free Software Foundation, Inc.,
|
||||
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
||||
|
||||
Also add information on how to contact you by electronic and paper mail.
|
||||
|
||||
@ -336,5 +335,5 @@ necessary. Here is a sample; alter the names:
|
||||
This General Public License does not permit incorporating your program into
|
||||
proprietary programs. If your program is a subroutine library, you may
|
||||
consider it more useful to permit linking proprietary applications with the
|
||||
library. If this is what you want to do, use the GNU Library General
|
||||
library. If this is what you want to do, use the GNU Lesser General
|
||||
Public License instead of this License.
|
||||
|
47
ChangeLog
47
ChangeLog
@ -1,3 +1,50 @@
|
||||
2014-07-30 Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
|
||||
|
||||
version 1.0
|
||||
* Recursive hashing
|
||||
* Immutable EVM signatures (experimental)
|
||||
* Command 'ima_clear' to remove xattrs
|
||||
* Support for passing password to the library
|
||||
* Support for asking password safely from the user
|
||||
|
||||
2014-09-23 Dmitry Kasatkin <d.kasatkin@samsung.com>
|
||||
|
||||
version 0.9
|
||||
* Updated README
|
||||
* man page generated and added to the package
|
||||
* Use additional SMACK xattrs for EVM signature generation
|
||||
* Signing functions moved to libimaevm for external use (RPM)
|
||||
* Fixed setting of correct hash header
|
||||
|
||||
2014-05-05 Dmitry Kasatkin <d.kasatkin@samsung.com>
|
||||
|
||||
version 0.8
|
||||
* Symbilic names for keyrings
|
||||
* Hash list signing
|
||||
* License text fix for using OpenSSL
|
||||
* Help output fix
|
||||
|
||||
2014-02-17 Dmitry Kasatkin <d.kasatkin@samsung.com>
|
||||
|
||||
version 0.7
|
||||
* Fix symbolic links related bugs
|
||||
* Provide recursive fixing
|
||||
* Provide recursive signing
|
||||
* Move IMA verification to the library (first for LTP use)
|
||||
* Support for target architecture data size
|
||||
* Remove obsolete module signing code
|
||||
* Code cleanup
|
||||
|
||||
2013-08-28 Dmitry Kasatkin <d.kasatkin@samsung.com>
|
||||
|
||||
version 0.6
|
||||
* support for asymmetric crypto keys and new signature format (v2)
|
||||
* fixes to set correct hash algo for digital signature v1
|
||||
* uuid support for EVM
|
||||
* signature verification support
|
||||
* test scripts removed
|
||||
* README updates
|
||||
|
||||
2012-05-18 Dmitry Kasatkin <dmitry.kasatkin@intel.com>
|
||||
|
||||
version 0.3
|
||||
|
8
INSTALL
8
INSTALL
@ -1,7 +1,7 @@
|
||||
Installation Instructions
|
||||
*************************
|
||||
|
||||
Copyright (C) 1994-1996, 1999-2002, 2004-2011 Free Software Foundation,
|
||||
Copyright (C) 1994-1996, 1999-2002, 2004-2013 Free Software Foundation,
|
||||
Inc.
|
||||
|
||||
Copying and distribution of this file, with or without modification,
|
||||
@ -309,9 +309,10 @@ causes the specified `gcc' to be used as the C compiler (unless it is
|
||||
overridden in the site shell script).
|
||||
|
||||
Unfortunately, this technique does not work for `CONFIG_SHELL' due to
|
||||
an Autoconf bug. Until the bug is fixed you can use this workaround:
|
||||
an Autoconf limitation. Until the limitation is lifted, you can use
|
||||
this workaround:
|
||||
|
||||
CONFIG_SHELL=/bin/bash /bin/bash ./configure CONFIG_SHELL=/bin/bash
|
||||
CONFIG_SHELL=/bin/bash ./configure CONFIG_SHELL=/bin/bash
|
||||
|
||||
`configure' Invocation
|
||||
======================
|
||||
@ -367,4 +368,3 @@ operates.
|
||||
|
||||
`configure' also accepts some other, not widely useful, options. Run
|
||||
`configure --help' for more details.
|
||||
|
||||
|
22
Makefile.am
22
Makefile.am
@ -1,6 +1,10 @@
|
||||
SUBDIRS = src
|
||||
dist_man_MANS = evmctl.1
|
||||
|
||||
#EXTRA_DIST = LEGAL acinclude.m4 include
|
||||
doc_DATA = examples/ima-genkey-self.sh examples/ima-genkey.sh examples/ima-gen-local-ca.sh
|
||||
EXTRA_DIST = autogen.sh $(doc_DATA)
|
||||
|
||||
CLEANFILES = *.html *.xsl
|
||||
|
||||
ACLOCAL_AMFLAGS = -I m4
|
||||
|
||||
@ -19,4 +23,20 @@ rpm: $(tarname)
|
||||
cp $(tarname) $(SRCS)/
|
||||
rpmbuild -ba --nodeps $(SPEC)
|
||||
|
||||
# requires asciidoc, xslproc, docbook-xsl
|
||||
MANPAGE_DOCBOOK_XSL = /usr/share/xml/docbook/stylesheet/docbook-xsl/manpages/docbook.xsl
|
||||
|
||||
evmctl.1.html: README
|
||||
@asciidoc -o $@ $<
|
||||
|
||||
evmctl.1:
|
||||
asciidoc -d manpage -b docbook -o evmctl.1.xsl README
|
||||
xsltproc --nonet -o $@ $(MANPAGE_DOCBOOK_XSL) evmctl.1.xsl
|
||||
rm -f evmctl.1.xsl
|
||||
|
||||
rmman:
|
||||
rm -f evmctl.1
|
||||
|
||||
doc: evmctl.1.html rmman evmctl.1
|
||||
|
||||
.PHONY: $(tarname)
|
||||
|
442
README
442
README
@ -1,47 +1,185 @@
|
||||
ima-evm-utils - IMA/EVM signing utility
|
||||
=========================================
|
||||
EVMCTL(1)
|
||||
=========
|
||||
|
||||
Contents:
|
||||
NAME
|
||||
----
|
||||
|
||||
1. Key and signature formats
|
||||
2. Key generation
|
||||
3. Initialization
|
||||
4. Signing
|
||||
evmctl - IMA/EVM signing utility
|
||||
|
||||
|
||||
SYNOPSIS
|
||||
--------
|
||||
|
||||
evmctl [options] <command> [OPTIONS]
|
||||
|
||||
|
||||
DESCRIPTION
|
||||
-----------
|
||||
|
||||
The evmctl utility can be used for producing and verifying digital signatures,
|
||||
which are used by Linux kernel integrity subsystem (IMA/EVM). It can be also
|
||||
used to import keys into the kernel keyring.
|
||||
|
||||
COMMANDS
|
||||
--------
|
||||
|
||||
--version
|
||||
help <command>
|
||||
import [--rsa] pubkey keyring
|
||||
sign [-r] [--imahash | --imasig ] [--key key] [--pass password] file
|
||||
verify file
|
||||
ima_sign [--sigfile] [--key key] [--pass password] file
|
||||
ima_verify file
|
||||
ima_hash file
|
||||
ima_measurement file
|
||||
ima_fix [-t fdsxm] path
|
||||
sign_hash [--key key] [--pass password]
|
||||
hmac [--imahash | --imasig ] file
|
||||
|
||||
|
||||
OPTIONS
|
||||
-------
|
||||
|
||||
-a, --hashalgo sha1 (default), sha224, sha256, sha384, sha512
|
||||
-s, --imasig make IMA signature
|
||||
-d, --imahash make IMA hash
|
||||
-f, --sigfile store IMA signature in .sig file instead of xattr
|
||||
--rsa use RSA key type and signing scheme v1
|
||||
-k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem)
|
||||
-p, --pass password for encrypted signing key
|
||||
-r, --recursive recurse into directories (sign)
|
||||
-t, --type file types to fix 'fdsxm' (f: file, d: directory, s: block/char/symlink)
|
||||
x - skip fixing if both ima and evm xattrs exist (use with caution)
|
||||
m - stay on the same filesystem (like 'find -xdev')
|
||||
-n print result to stdout instead of setting xattr
|
||||
-u, --uuid use custom FS UUID for EVM (unspecified: from FS, empty: do not use)
|
||||
--smack use extra SMACK xattrs for EVM
|
||||
--m32 force EVM hmac/signature for 32 bit target system
|
||||
--m64 force EVM hmac/signature for 64 bit target system
|
||||
-v increase verbosity level
|
||||
-h, --help display this help and exit
|
||||
|
||||
|
||||
INTRODUCTION
|
||||
------------
|
||||
|
||||
Linux kernel integrity subsystem is comprised of a number of different components
|
||||
including the Integrity Measurement Architecture (IMA), Extended Verification Module
|
||||
(EVM), IMA-appraisal extension, digital signature verification extension and audit
|
||||
measurement log support.
|
||||
|
||||
The evmctl utility is used for producing and verifying digital signatures, which
|
||||
are used by the Linux kernel integrity subsystem. It is also used for importing keys
|
||||
into the kernel keyring.
|
||||
|
||||
Linux integrity subsystem allows to use IMA and EVM signatures. EVM signature
|
||||
protects file metadata, such as file attributes and extended attributes. IMA
|
||||
signature protects file content.
|
||||
|
||||
For more detailed information about integrity subsystem it is recommended to follow
|
||||
resources in RESOURCES section.
|
||||
|
||||
|
||||
EVM HMAC and signature metadata
|
||||
-------------------------------
|
||||
|
||||
EVM protects file metadata by including following attributes into HMAC and signature
|
||||
calculation: inode number, inode generation, UID, GID, file mode, security.selinux,
|
||||
security.SMACK64, security.ima, security.capability.
|
||||
|
||||
EVM HMAC and signature in may also include additional file and file system attributes.
|
||||
Currently supported additional attributes are filesystem UUID and extra SMACK
|
||||
extended attributes.
|
||||
|
||||
Kernel configuration option CONFIG_EVM_ATTR_FSUUID controls whether to include
|
||||
filesystem UUID into HMAC and enabled by default. Therefore evmctl also includes
|
||||
fsuuid by default. Providing '--uuid' option without parameter allows to disable
|
||||
usage of fs uuid. Providing '--uuid=UUID' option with parameter allows to use
|
||||
custom UUID.
|
||||
|
||||
Kernel configuration option CONFIG_EVM_EXTRA_SMACK_XATTRS controls whether to
|
||||
include additional SMACK extended attributes into HMAC. They are following:
|
||||
security.SMACK64EXEC, security.SMACK64TRANSMUTE and security.SMACK64MMAP.
|
||||
evmctl '--smack' options enables that.
|
||||
|
||||
|
||||
Key and signature formats
|
||||
-------------------------
|
||||
|
||||
EVM support (v2) in latest version of the kernel adds the file system UUID to
|
||||
the HMAC calculation. It is controlled by the CONFIG_EVM_HMAC_VERSION and
|
||||
version 2 is enabled by default. To include the UUID to the signature calculation,
|
||||
it is necessary to provide '--uuid -' or '-u -' parameter to the 'sign' command.
|
||||
Linux integrity subsystem supports two type of signature and respectively two
|
||||
key formats.
|
||||
|
||||
Latest kernel got IMA/EVM support for using X509 certificates and asymmetric key
|
||||
support for verifying digital signatures. The new command line parameter
|
||||
'-x' or '--x509' was added to the evmctl to enable using of X509 certificates
|
||||
and new signature format.
|
||||
First key format (v1) is pure RSA key encoded in PEM a format and uses own signature
|
||||
format. It is now non-default format and requires to provide evmctl '--rsa' option
|
||||
for signing and importing the key.
|
||||
|
||||
Second key format uses X509 DER encoded public key certificates and uses asymmetric key support
|
||||
in the kernel (since kernel 3.9). CONFIG_INTEGRITY_ASYMMETRIC_KEYS must be enabled (default).
|
||||
|
||||
|
||||
Key generation
|
||||
--------------
|
||||
Integrity keyrings
|
||||
----------------
|
||||
|
||||
Generate private key in plain text format
|
||||
Integrity subsystem uses dedicated IMA/EVM keyrings to search for signature verification
|
||||
keys - '_ima' and '_evm' respectively.
|
||||
|
||||
$ openssl genrsa -out privkey_evm.pem 1024
|
||||
Since 3.13 IMA allows to declare IMA keyring as trusted. It allows only to load keys,
|
||||
signed by a key from the system keyring (.system). It means self-signed keys are not
|
||||
allowed. This is a default behavior unless CONFIG_IMA_TRUSTED_KEYRING is undefined.
|
||||
IMA trusted keyring is has different name '.ima'. Trusted keyring requires X509
|
||||
public key certificates. Old version RSA public keys are not compatible with trusted
|
||||
keyring.
|
||||
|
||||
Generate encrypted private key
|
||||
|
||||
$ openssl genrsa -des3 -out privkey_evm.pem 1024
|
||||
Generate EVM encrypted keys
|
||||
---------------------------
|
||||
|
||||
Make encrypted private key from unencrypted
|
||||
EVM encrypted key is used for EVM HMAC calculation:
|
||||
|
||||
$ openssl rsa -in /etc/keys/privkey_evm.pem -out privkey_evm_enc.pem -des3
|
||||
# create and save the key kernel master key (user type)
|
||||
# LMK is used to encrypt encrypted keys
|
||||
keyctl add user kmk "`dd if=/dev/urandom bs=1 count=32 2>/dev/null`" @u
|
||||
keyctl pipe `keyctl search @u user kmk` > /etc/keys/kmk
|
||||
|
||||
Generate self-signed X509 certificate and private key for using kernel asymmetric
|
||||
keys support
|
||||
# create the EVM encrypted key
|
||||
keyctl add encrypted evm-key "new user:kmk 64" @u
|
||||
keyctl pipe `keyctl search @u encrypted evm-key` >/etc/keys/evm-key
|
||||
|
||||
$ openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
|
||||
|
||||
Generate EVM trusted keys (TPM based)
|
||||
-------------------------------------
|
||||
|
||||
Trusted EVM keys are keys which a generate with the help of TPM.
|
||||
They are not related to integrity trusted keys.
|
||||
|
||||
# create and save the key kernel master key (user type)
|
||||
keyctl add trusted kmk "new 32" @u
|
||||
keyctl pipe `keyctl search @u trusted kmk` >kmk
|
||||
|
||||
# create the EVM trusted key
|
||||
keyctl add encrypted evm-key "new trusted:kmk 32" @u
|
||||
keyctl pipe `keyctl search @u encrypted evm-key` >evm-key
|
||||
|
||||
|
||||
Generate signing and verification keys
|
||||
--------------------------------------
|
||||
|
||||
Generate private key in plain text format:
|
||||
|
||||
openssl genrsa -out privkey_evm.pem 1024
|
||||
|
||||
Generate encrypted private key:
|
||||
|
||||
openssl genrsa -des3 -out privkey_evm.pem 1024
|
||||
|
||||
Make encrypted private key from unencrypted:
|
||||
|
||||
openssl rsa -in /etc/keys/privkey_evm.pem -out privkey_evm_enc.pem -des3
|
||||
|
||||
Generate self-signed X509 public key certificate and private key for using kernel
|
||||
asymmetric keys support:
|
||||
|
||||
openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
|
||||
-x509 -config x509_evm.genkey \
|
||||
-outform DER -out x509_evm.der -keyout privkey_evm.pem
|
||||
|
||||
@ -68,78 +206,232 @@ Configuration file x509_evm.genkey:
|
||||
# EOF
|
||||
|
||||
|
||||
Get public key
|
||||
Generate public key for using RSA key format:
|
||||
|
||||
$ openssl rsa -pubout -in privkey_evm.pem -out pubkey_evm.pem
|
||||
openssl rsa -pubout -in privkey_evm.pem -out pubkey_evm.pem
|
||||
|
||||
Copy keys to /etc/keys
|
||||
|
||||
$ cp pubkey_evm.pem /etc/keys
|
||||
$ scp pubkey_evm.pem target:/etc/keys
|
||||
Copy keys to /etc/keys:
|
||||
|
||||
cp pubkey_evm.pem /etc/keys
|
||||
scp pubkey_evm.pem target:/etc/keys
|
||||
or
|
||||
$ cp x509_evm.pem /etc/keys
|
||||
$ scp x509_evm.pem target:/etc/keys
|
||||
cp x509_evm.pem /etc/keys
|
||||
scp x509_evm.pem target:/etc/keys
|
||||
|
||||
|
||||
Initialization
|
||||
--------------
|
||||
Generate trusted keys
|
||||
---------------------
|
||||
|
||||
Generation of trusted keys is a bit more complicated process and involves
|
||||
following steps:
|
||||
|
||||
* Creation of local IMA certification authority (CA).
|
||||
It consist of private and public key certificate which are used
|
||||
to sign and verify other keys.
|
||||
* Build Linux kernel with embedded local IMA CA X509 certificate.
|
||||
It is used to verify other keys added to the '.ima' trusted keyring
|
||||
* Generate IMA private signing key and verification public key certificate,
|
||||
which is signed using local IMA CA private key.
|
||||
|
||||
Configuration file ima-local-ca.genkey:
|
||||
|
||||
# Begining of the file
|
||||
[ req ]
|
||||
default_bits = 2048
|
||||
distinguished_name = req_distinguished_name
|
||||
prompt = no
|
||||
string_mask = utf8only
|
||||
x509_extensions = v3_ca
|
||||
|
||||
[ req_distinguished_name ]
|
||||
O = IMA-CA
|
||||
CN = IMA/EVM certificate signing key
|
||||
emailAddress = ca@ima-ca
|
||||
|
||||
[ v3_ca ]
|
||||
basicConstraints=CA:TRUE
|
||||
subjectKeyIdentifier=hash
|
||||
authorityKeyIdentifier=keyid:always,issuer
|
||||
# keyUsage = cRLSign, keyCertSign
|
||||
# EOF
|
||||
|
||||
Generate private key and X509 public key certificate:
|
||||
|
||||
openssl req -new -x509 -utf8 -sha1 -days 3650 -batch -config $GENKEY \
|
||||
-outform DER -out ima-local-ca.x509 -keyout ima-local-ca.priv
|
||||
|
||||
Produce X509 in DER format for using while building the kernel:
|
||||
|
||||
openssl x509 -inform DER -in ima-local-ca.x509 -out ima-local-ca.pem
|
||||
|
||||
Configuration file ima.genkey:
|
||||
|
||||
# Begining of the file
|
||||
[ req ]
|
||||
default_bits = 1024
|
||||
distinguished_name = req_distinguished_name
|
||||
prompt = no
|
||||
string_mask = utf8only
|
||||
x509_extensions = v3_usr
|
||||
|
||||
[ req_distinguished_name ]
|
||||
O = `hostname`
|
||||
CN = `whoami` signing key
|
||||
emailAddress = `whoami`@`hostname`
|
||||
|
||||
[ v3_usr ]
|
||||
basicConstraints=critical,CA:FALSE
|
||||
#basicConstraints=CA:FALSE
|
||||
keyUsage=digitalSignature
|
||||
#keyUsage = nonRepudiation, digitalSignature, keyEncipherment
|
||||
subjectKeyIdentifier=hash
|
||||
authorityKeyIdentifier=keyid
|
||||
#authorityKeyIdentifier=keyid,issuer
|
||||
# EOF
|
||||
|
||||
|
||||
Generate private key and X509 public key certificate signing request:
|
||||
|
||||
openssl req -new -nodes -utf8 -sha1 -days 365 -batch -config $GENKEY \
|
||||
-out csr_ima.pem -keyout privkey_ima.pem
|
||||
|
||||
Sign X509 public key certificate signing request with local IMA CA private key:
|
||||
|
||||
openssl x509 -req -in csr_ima.pem -days 365 -extfile $GENKEY -extensions v3_usr \
|
||||
-CA ima-local-ca.pem -CAkey ima-local-ca.priv -CAcreateserial \
|
||||
-outform DER -out x509_ima.der
|
||||
|
||||
|
||||
Sign file data and metadata
|
||||
---------------------------
|
||||
|
||||
Default key locations:
|
||||
|
||||
Private RSA key: /etc/keys/privkey_evm.pem
|
||||
Public RSA key: /etc/keys/pubkey_evm.pem
|
||||
X509 certificate: /etc/keys/x509_evm.der
|
||||
|
||||
Options to remember: '-k', '-r', '--rsa', '--uuid', '--smack'.
|
||||
|
||||
Sign file with EVM signature and calculate hash value for IMA:
|
||||
|
||||
evmctl sign --imahash test.txt
|
||||
|
||||
Sign file with both IMA and EVM signatures:
|
||||
|
||||
evmctl sign --imasig test.txt:
|
||||
|
||||
Sign file with IMA signature:
|
||||
|
||||
evmctl ima_sign test.txt
|
||||
|
||||
Sign recursively whole filesystem:
|
||||
|
||||
evmctl -r sign --imahash /
|
||||
|
||||
Fix recursively whole filesystem:
|
||||
|
||||
evmctl -r ima_fix /
|
||||
|
||||
Sign filesystem selectively using 'find' command:
|
||||
|
||||
find / \( -fstype rootfs -o -fstype ext4 \) -exec evmctl sign --imahash '{}' \;
|
||||
|
||||
Fix filesystem selectively using 'find' command:
|
||||
|
||||
find / \( -fstype rootfs -o -fstype ext4 \) -exec sh -c "< '{}'" \;
|
||||
|
||||
|
||||
Initialize IMA/EVM at early boot
|
||||
--------------------------------
|
||||
|
||||
IMA/EVM initialization should be normally done from initial RAM file system
|
||||
before mounting root filesystem.
|
||||
|
||||
Here is an example script /etc/initramfs-tools/scripts/local-top/ima.sh
|
||||
Here is Ubuntu initramfs example script (/etc/initramfs-tools/scripts/local-top/ima.sh)
|
||||
|
||||
# import EVM HMAC key
|
||||
keyctl clear @u
|
||||
keyctl add user kmk "testing123" @u
|
||||
keyctl add encrypted evm-key "load `cat /etc/keys/evm-key`" @u
|
||||
# mount securityfs if not mounted
|
||||
SECFS=/sys/kernel/security
|
||||
grep -q $SECFS /proc/mounts || mount -n -t securityfs securityfs $SECFS
|
||||
|
||||
# import IMA public key
|
||||
# search for IMA trusted keyring, then for untrusted
|
||||
ima_id="`awk '/\.ima/ { printf "%d", "0x"$1; }' /proc/keys`"
|
||||
if [ -z "$ima_id" ]; then
|
||||
ima_id=`keyctl search @u keyring _ima 2>/dev/null`
|
||||
if [ -z "$ima_id" ]; then
|
||||
ima_id=`keyctl newring _ima @u`
|
||||
evmctl import /etc/keys/pubkey_evm.pem $ima_id
|
||||
fi
|
||||
fi
|
||||
# import IMA X509 certificate
|
||||
evmctl import /etc/keys/x509_ima.der $ima_id
|
||||
|
||||
# import EVM public key
|
||||
# search for EVM keyring
|
||||
evm_id=`keyctl search @u keyring _evm 2>/dev/null`
|
||||
if [ -z "$evm_id" ]; then
|
||||
evm_id=`keyctl newring _evm @u`
|
||||
evmctl import /etc/keys/pubkey_evm.pem $evm_id
|
||||
fi
|
||||
# import EVM X509 certificate
|
||||
evmctl import /etc/keys/x509_evm.der $evm_id
|
||||
|
||||
# a) import EVM encrypted key
|
||||
cat /etc/keys/kmk | keyctl padd user kmk @u
|
||||
keyctl add encrypted evm-key "load `cat /etc/keys/evm-key`" @u
|
||||
# OR
|
||||
# b) import EVM trusted key
|
||||
keyctl add trusted kmk "load `cat /etc/keys/kmk`" @u
|
||||
keyctl add encrypted evm-key "load `cat /etc/keys/evm-key`" @u
|
||||
|
||||
# enable EVM
|
||||
echo "1" > /sys/kernel/security/evm
|
||||
|
||||
Optionally it is possible also to forbid adding, removing of new public keys
|
||||
and certificates into keyrings and revoking keys using 'keyctl setperm' command:
|
||||
|
||||
Import X509 certificate into the kernel keyring (since kernel 3.9?)
|
||||
|
||||
$ evmctl -x import /etc/keys/x509_evm.der `keyctl search @u keyring _ima`
|
||||
$ evmctl -x import /etc/keys/x509_evm.der `keyctl search @u keyring _evm`
|
||||
# protect EVM keyring
|
||||
keyctl setperm $evm_id 0x0b0b0000
|
||||
# protect IMA keyring
|
||||
keyctl setperm $ima_id 0x0b0b0000
|
||||
# protecting IMA key from revoking (against DoS)
|
||||
ima_key=`evmctl import /etc/keys/x509_ima.der $ima_id`
|
||||
keyctl setperm $ima_key 0x0b0b0000
|
||||
|
||||
|
||||
Signing
|
||||
When using plain RSA public keys in PEM format, use 'evmctl import --rsa' for importing keys:
|
||||
|
||||
evmctl import --rsa /etc/keys/pubkey_evm.pem $evm_id
|
||||
|
||||
Latest version of keyctl allows to import X509 public key certificates:
|
||||
|
||||
cat /etc/keys/x509_ima.der | keyctl padd asymmetric '' $ima_id
|
||||
|
||||
|
||||
FILES
|
||||
-----
|
||||
|
||||
Examples of scripts to generate X509 public key certificates:
|
||||
|
||||
/usr/share/doc/ima-evm-utils/ima-genkey-self.sh
|
||||
/usr/share/doc/ima-evm-utils/ima-genkey.sh
|
||||
/usr/share/doc/ima-evm-utils/ima-gen-local-ca.sh
|
||||
|
||||
|
||||
AUTHOR
|
||||
------
|
||||
|
||||
Written by Dmitry Kasatkin, <dmitry.kasatkin at gmail.com> and others.
|
||||
|
||||
|
||||
RESOURCES
|
||||
---------
|
||||
|
||||
http://sourceforge.net/p/linux-ima/wiki/Home
|
||||
http://sourceforge.net/p/linux-ima/ima-evm-utils
|
||||
|
||||
|
||||
COPYING
|
||||
-------
|
||||
|
||||
Default public key: /etc/keys/pubkey_evm.pem
|
||||
Default private key: /etc/keys/privkey_evm.pem
|
||||
Default X509 certificate: /etc/keys/x509_evm.der
|
||||
|
||||
Signing for using X509 certificates is done using '-x' or '--x509' parameter.
|
||||
Signing for using new the EVM HMAC format is done using '-u -' or '--uuid -' parameter.
|
||||
|
||||
Sign file with EVM signature and use hash value for IMA - common case
|
||||
|
||||
$ evmctl sign [-u -] [-x] --imahash test.txt
|
||||
|
||||
Sign file with both IMA and EVM signatures - for immutable files
|
||||
|
||||
$ evmctl sign [-u -] [-x] --imasig test.txt
|
||||
|
||||
Sign file with IMA signature - for immutable files
|
||||
|
||||
$ evmctl ima_sign [-x] test.txt
|
||||
|
||||
Label whole filesystem with EVM signatures
|
||||
|
||||
$ find / \( -fstype rootfs -o -fstype ext4 \) -exec evmctl sign [-u -] [-x] --imahash '{}' \;
|
||||
|
||||
Label filesystem in fix mode - kernel sets correct values to IMA and EVM xattrs
|
||||
|
||||
$ find / \( -fstype rootfs -o -fstype ext4 \) -exec sh -c "< '{}'" \;
|
||||
Copyright \(C) 2012 - 2014 Linux Integrity Project. Free use of this software is granted under
|
||||
the terms of the GNU Public License (GPL).
|
||||
|
||||
|
4
build-static.sh
Executable file
4
build-static.sh
Executable file
@ -0,0 +1,4 @@
|
||||
#!/bin/sh
|
||||
|
||||
gcc -static -o evmctl.static -include config.h src/evmctl.c src/libimaevm.c -lcrypto -lkeyutils -ldl
|
||||
|
@ -1,8 +1,8 @@
|
||||
# autoconf script
|
||||
|
||||
AC_PREREQ([2.65])
|
||||
AC_INIT(ima-evm-utils, 0.3, dmitry.kasatkin@intel.com)
|
||||
AM_INIT_AUTOMAKE(AC_PACKAGE_NAME, AC_PACKAGE_VERSION)
|
||||
AC_INIT(ima-evm-utils, 1.0, dmitry.kasatkin@huawei.com)
|
||||
AM_INIT_AUTOMAKE
|
||||
AC_CONFIG_HEADERS([config.h])
|
||||
AC_CONFIG_MACRO_DIR([m4])
|
||||
|
||||
@ -30,6 +30,9 @@ AC_SUBST(OPENSSL_LIBS)
|
||||
AC_CHECK_HEADER(unistd.h)
|
||||
AC_CHECK_HEADERS(openssl/conf.h)
|
||||
|
||||
AC_CHECK_HEADERS(attr/xattr.h, , [AC_MSG_ERROR([attr/xattr.h header not found. You need the libattr development package.])])
|
||||
AC_CHECK_HEADERS(keyutils.h, , [AC_MSG_ERROR([keyutils.h header not found. You need the libkeyutils development package.])])
|
||||
|
||||
#debug support - yes for a while
|
||||
PKG_ARG_ENABLE(debug, "yes", DEBUG, [Enable Debug support])
|
||||
if test $pkg_cv_enable_debug = yes; then
|
||||
@ -46,7 +49,7 @@ fi
|
||||
|
||||
AC_CONFIG_FILES([Makefile
|
||||
src/Makefile
|
||||
ima-evm-utils.spec
|
||||
packaging/ima-evm-utils.spec
|
||||
])
|
||||
AC_OUTPUT
|
||||
|
||||
|
29
examples/ima-gen-local-ca.sh
Executable file
29
examples/ima-gen-local-ca.sh
Executable file
@ -0,0 +1,29 @@
|
||||
#!/bin/sh
|
||||
|
||||
GENKEY=ima-local-ca.genkey
|
||||
|
||||
cat << __EOF__ >$GENKEY
|
||||
[ req ]
|
||||
default_bits = 2048
|
||||
distinguished_name = req_distinguished_name
|
||||
prompt = no
|
||||
string_mask = utf8only
|
||||
x509_extensions = v3_ca
|
||||
|
||||
[ req_distinguished_name ]
|
||||
O = IMA-CA
|
||||
CN = IMA/EVM certificate signing key
|
||||
emailAddress = ca@ima-ca
|
||||
|
||||
[ v3_ca ]
|
||||
basicConstraints=CA:TRUE
|
||||
subjectKeyIdentifier=hash
|
||||
authorityKeyIdentifier=keyid:always,issuer
|
||||
# keyUsage = cRLSign, keyCertSign
|
||||
__EOF__
|
||||
|
||||
openssl req -new -x509 -utf8 -sha1 -days 3650 -batch -config $GENKEY \
|
||||
-outform DER -out ima-local-ca.x509 -keyout ima-local-ca.priv
|
||||
|
||||
openssl x509 -inform DER -in ima-local-ca.x509 -out ima-local-ca.pem
|
||||
|
29
examples/ima-genkey-self.sh
Executable file
29
examples/ima-genkey-self.sh
Executable file
@ -0,0 +1,29 @@
|
||||
#!/bin/sh
|
||||
|
||||
GENKEY=x509_evm.genkey
|
||||
|
||||
cat << __EOF__ >$GENKEY
|
||||
[ req ]
|
||||
default_bits = 1024
|
||||
distinguished_name = req_distinguished_name
|
||||
prompt = no
|
||||
string_mask = utf8only
|
||||
x509_extensions = myexts
|
||||
|
||||
[ req_distinguished_name ]
|
||||
O = `hostname`
|
||||
CN = `whoami` signing key
|
||||
emailAddress = `whoami`@`hostname`
|
||||
|
||||
[ myexts ]
|
||||
basicConstraints=critical,CA:FALSE
|
||||
keyUsage=digitalSignature
|
||||
subjectKeyIdentifier=hash
|
||||
authorityKeyIdentifier=keyid
|
||||
__EOF__
|
||||
|
||||
openssl req -x509 -new -nodes -utf8 -sha1 -days 3650 -batch -config $GENKEY \
|
||||
-outform DER -out x509_evm.der -keyout privkey_evm.pem
|
||||
|
||||
openssl rsa -pubout -in privkey_evm.pem -out pubkey_evm.pem
|
||||
|
33
examples/ima-genkey.sh
Executable file
33
examples/ima-genkey.sh
Executable file
@ -0,0 +1,33 @@
|
||||
#!/bin/sh
|
||||
|
||||
GENKEY=ima.genkey
|
||||
|
||||
cat << __EOF__ >$GENKEY
|
||||
[ req ]
|
||||
default_bits = 1024
|
||||
distinguished_name = req_distinguished_name
|
||||
prompt = no
|
||||
string_mask = utf8only
|
||||
x509_extensions = v3_usr
|
||||
|
||||
[ req_distinguished_name ]
|
||||
O = `hostname`
|
||||
CN = `whoami` signing key
|
||||
emailAddress = `whoami`@`hostname`
|
||||
|
||||
[ v3_usr ]
|
||||
basicConstraints=critical,CA:FALSE
|
||||
#basicConstraints=CA:FALSE
|
||||
keyUsage=digitalSignature
|
||||
#keyUsage = nonRepudiation, digitalSignature, keyEncipherment
|
||||
subjectKeyIdentifier=hash
|
||||
authorityKeyIdentifier=keyid
|
||||
#authorityKeyIdentifier=keyid,issuer
|
||||
__EOF__
|
||||
|
||||
openssl req -new -nodes -utf8 -sha1 -days 365 -batch -config $GENKEY \
|
||||
-out csr_ima.pem -keyout privkey_ima.pem
|
||||
openssl x509 -req -in csr_ima.pem -days 365 -extfile $GENKEY -extensions v3_usr \
|
||||
-CA ima-local-ca.pem -CAkey ima-local-ca.priv -CAcreateserial \
|
||||
-outform DER -out x509_ima.der
|
||||
|
53
packaging/ima-evm-utils.spec
Normal file
53
packaging/ima-evm-utils.spec
Normal file
@ -0,0 +1,53 @@
|
||||
Name: ima-evm-utils
|
||||
Version: 1.0
|
||||
Release: 1%{?dist}
|
||||
Summary: ima-evm-utils - IMA/EVM control utility
|
||||
Group: System/Libraries
|
||||
License: GPLv2
|
||||
#URL:
|
||||
Source0: %{name}-%{version}.tar.gz
|
||||
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
|
||||
|
||||
BuildRequires: autoconf
|
||||
BuildRequires: automake
|
||||
BuildRequires: openssl-devel
|
||||
BuildRequires: libattr-devel
|
||||
BuildRequires: keyutils-libs-devel
|
||||
|
||||
%description
|
||||
This package provide IMA/EVM control utility
|
||||
|
||||
%prep
|
||||
%setup -q
|
||||
|
||||
%build
|
||||
./autogen.sh
|
||||
%configure --prefix=/usr
|
||||
make
|
||||
|
||||
%install
|
||||
rm -rf %{buildroot}
|
||||
make DESTDIR=%{buildroot} install
|
||||
|
||||
%clean
|
||||
rm -rf %{buildroot}
|
||||
|
||||
%post
|
||||
/sbin/ldconfig
|
||||
exit 0
|
||||
|
||||
%preun -p /sbin/ldconfig
|
||||
|
||||
%postun
|
||||
/sbin/ldconfig
|
||||
|
||||
%files
|
||||
%defattr(-,root,root,-)
|
||||
%{_bindir}/*
|
||||
%{_libdir}/libimaevm.*
|
||||
%{_includedir}/*
|
||||
|
||||
%changelog
|
||||
* Thu Apr 05 2012 Dmitry Kasatkin <dmitry.kasatkin@intel.com>
|
||||
- Initial RPM spec file
|
||||
|
@ -3,7 +3,7 @@ Version: @PACKAGE_VERSION@
|
||||
Release: 1%{?dist}
|
||||
Summary: @PACKAGE_NAME@ - IMA/EVM control utility
|
||||
Group: System/Libraries
|
||||
License: LGPLv2
|
||||
License: GPLv2
|
||||
#URL:
|
||||
Source0: %{name}-%{version}.tar.gz
|
||||
BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-root
|
||||
@ -44,7 +44,8 @@ exit 0
|
||||
%files
|
||||
%defattr(-,root,root,-)
|
||||
%{_bindir}/*
|
||||
%{_libdir}/*
|
||||
%{_libdir}/libimaevm.*
|
||||
%{_includedir}/*
|
||||
|
||||
%changelog
|
||||
* Thu Apr 05 2012 Dmitry Kasatkin <dmitry.kasatkin@intel.com>
|
@ -1,10 +1,20 @@
|
||||
lib_LTLIBRARIES = libimaevm.la
|
||||
|
||||
libimaevm_la_SOURCES = libimaevm.c
|
||||
libimaevm_la_CPPFLAGS = $(OPENSSL_CFLAGS)
|
||||
# current[:revision[:age]]
|
||||
# result: [current-age].age.revision
|
||||
libimaevm_la_LDFLAGS = -version-info 0:0:0
|
||||
libimaevm_la_LIBADD = $(OPENSSL_LIBS)
|
||||
|
||||
include_HEADERS = imaevm.h
|
||||
|
||||
bin_PROGRAMS = evmctl
|
||||
|
||||
evmctl_SOURCES = evmctl.c
|
||||
evmctl_CPPFLAGS = $(OPENSSL_CFLAGS)
|
||||
evmctl_LDFLAGS = $(LDFLAGS_READLINE)
|
||||
evmctl_LDADD = $(OPENSSL_LIBS) -lkeyutils
|
||||
evmctl_LDADD = $(OPENSSL_LIBS) -lkeyutils libimaevm.la
|
||||
|
||||
INCLUDES = -I$(top_srcdir) -include config.h
|
||||
|
||||
|
2073
src/evmctl.c
2073
src/evmctl.c
File diff suppressed because it is too large
Load Diff
208
src/imaevm.h
Normal file
208
src/imaevm.h
Normal file
@ -0,0 +1,208 @@
|
||||
/*
|
||||
* ima-evm-utils - IMA/EVM support utilities
|
||||
*
|
||||
* Copyright (C) 2011 Nokia Corporation
|
||||
* Copyright (C) 2011,2012,2013 Intel Corporation
|
||||
* Copyright (C) 2013,2014 Samsung Electronics
|
||||
*
|
||||
* Authors:
|
||||
* Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
|
||||
* <dmitry.kasatkin@intel.com>
|
||||
* <d.kasatkin@samsung.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* version 2 as published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
* As a special exception, the copyright holders give permission to link the
|
||||
* code of portions of this program with the OpenSSL library under certain
|
||||
* conditions as described in each individual source file and distribute
|
||||
* linked combinations including the program with the OpenSSL library. You
|
||||
* must comply with the GNU General Public License in all respects
|
||||
* for all of the code used other than as permitted herein. If you modify
|
||||
* file(s) with this exception, you may extend this exception to your
|
||||
* version of the file(s), but you are not obligated to do so. If you do not
|
||||
* wish to do so, delete this exception statement from your version. If you
|
||||
* delete this exception statement from all source files in the program,
|
||||
* then also delete it in the license file.
|
||||
*
|
||||
* File: imaevm.h
|
||||
* IMA/EVM header file
|
||||
*/
|
||||
|
||||
#ifndef _LIBIMAEVM_H
|
||||
#define _LIBIMAEVM_H
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <stdint.h>
|
||||
#include <syslog.h>
|
||||
#include <stdbool.h>
|
||||
#include <errno.h>
|
||||
|
||||
#include <openssl/rsa.h>
|
||||
|
||||
#ifdef USE_FPRINTF
|
||||
#define do_log(level, fmt, args...) ({ if (level <= params.verbose) fprintf(stderr, fmt, ##args); })
|
||||
#define do_log_dump(level, p, len, cr) ({ if (level <= params.verbose) do_dump(stderr, p, len, cr); })
|
||||
#else
|
||||
#define do_log(level, fmt, args...) syslog(level, fmt, ##args)
|
||||
#define do_log_dump(level, p, len, cr)
|
||||
#endif
|
||||
|
||||
#ifdef DEBUG
|
||||
#define log_debug(fmt, args...) do_log(LOG_DEBUG, "%s:%d " fmt, __func__ , __LINE__ , ##args)
|
||||
#define log_debug_dump(p, len) do_log_dump(LOG_DEBUG, p, len, true)
|
||||
#define log_debug_dump_n(p, len) do_log_dump(LOG_DEBUG, p, len, false)
|
||||
#else
|
||||
#define log_debug(fmt, args...)
|
||||
#define log_debug_dump(p, len)
|
||||
#endif
|
||||
|
||||
#define log_dump(p, len) do_log_dump(LOG_INFO, p, len, true)
|
||||
#define log_dump_n(p, len) do_log_dump(LOG_INFO, p, len, false)
|
||||
#define log_info(fmt, args...) do_log(LOG_INFO, fmt, ##args)
|
||||
#define log_err(fmt, args...) do_log(LOG_ERR, fmt, ##args)
|
||||
#define log_errno(fmt, args...) do_log(LOG_ERR, fmt ": errno: %s (%d)\n", ##args, strerror(errno), errno)
|
||||
|
||||
#define DATA_SIZE 4096
|
||||
#define SHA1_HASH_LEN 20
|
||||
|
||||
#define __packed __attribute__((packed))
|
||||
|
||||
enum evm_ima_xattr_type {
|
||||
IMA_XATTR_DIGEST = 0x01,
|
||||
EVM_XATTR_HMAC,
|
||||
EVM_IMA_XATTR_DIGSIG,
|
||||
IMA_XATTR_DIGEST_NG,
|
||||
};
|
||||
|
||||
struct h_misc {
|
||||
unsigned long ino;
|
||||
uint32_t generation;
|
||||
uid_t uid;
|
||||
gid_t gid;
|
||||
unsigned short mode;
|
||||
};
|
||||
|
||||
struct h_misc_32 {
|
||||
uint32_t ino;
|
||||
uint32_t generation;
|
||||
uid_t uid;
|
||||
gid_t gid;
|
||||
unsigned short mode;
|
||||
};
|
||||
|
||||
struct h_misc_64 {
|
||||
uint64_t ino;
|
||||
uint32_t generation;
|
||||
uid_t uid;
|
||||
gid_t gid;
|
||||
unsigned short mode;
|
||||
};
|
||||
|
||||
struct h_misc_digsig {
|
||||
uid_t uid;
|
||||
gid_t gid;
|
||||
unsigned short mode;
|
||||
};
|
||||
|
||||
enum pubkey_algo {
|
||||
PUBKEY_ALGO_RSA,
|
||||
PUBKEY_ALGO_MAX,
|
||||
};
|
||||
|
||||
enum digest_algo {
|
||||
DIGEST_ALGO_SHA1,
|
||||
DIGEST_ALGO_SHA256,
|
||||
DIGEST_ALGO_MAX
|
||||
};
|
||||
|
||||
enum digsig_version {
|
||||
DIGSIG_VERSION_1 = 1,
|
||||
DIGSIG_VERSION_2
|
||||
};
|
||||
|
||||
struct pubkey_hdr {
|
||||
uint8_t version; /* key format version */
|
||||
uint32_t timestamp; /* key made, always 0 for now */
|
||||
uint8_t algo;
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
|
||||
struct signature_hdr {
|
||||
uint8_t version; /* signature format version */
|
||||
uint32_t timestamp; /* signature made */
|
||||
uint8_t algo;
|
||||
uint8_t hash;
|
||||
uint8_t keyid[8];
|
||||
uint8_t nmpi;
|
||||
char mpi[0];
|
||||
} __packed;
|
||||
|
||||
enum pkey_hash_algo {
|
||||
PKEY_HASH_MD4,
|
||||
PKEY_HASH_MD5,
|
||||
PKEY_HASH_SHA1,
|
||||
PKEY_HASH_RIPE_MD_160,
|
||||
PKEY_HASH_SHA256,
|
||||
PKEY_HASH_SHA384,
|
||||
PKEY_HASH_SHA512,
|
||||
PKEY_HASH_SHA224,
|
||||
PKEY_HASH__LAST
|
||||
};
|
||||
|
||||
/*
|
||||
* signature format v2 - for using with asymmetric keys
|
||||
*/
|
||||
struct signature_v2_hdr {
|
||||
uint8_t version; /* signature format version */
|
||||
uint8_t hash_algo; /* Digest algorithm [enum pkey_hash_algo] */
|
||||
uint32_t keyid; /* IMA key identifier - not X509/PGP specific*/
|
||||
uint16_t sig_size; /* signature size */
|
||||
uint8_t sig[0]; /* signature payload */
|
||||
} __packed;
|
||||
|
||||
|
||||
typedef int (*verify_hash_fn_t)(const unsigned char *hash, int size, unsigned char *sig, int siglen, const char *keyfile);
|
||||
|
||||
struct libevm_params {
|
||||
int verbose;
|
||||
int x509;
|
||||
const char *hash_algo;
|
||||
const char *keyfile;
|
||||
const char *keypass;
|
||||
};
|
||||
|
||||
struct RSA_ASN1_template {
|
||||
const uint8_t *data;
|
||||
size_t size;
|
||||
};
|
||||
|
||||
extern const struct RSA_ASN1_template RSA_ASN1_templates[PKEY_HASH__LAST];
|
||||
extern struct libevm_params params;
|
||||
|
||||
void do_dump(FILE *fp, const void *ptr, int len, bool cr);
|
||||
void dump(const void *ptr, int len);
|
||||
int get_filesize(const char *filename);
|
||||
int ima_calc_hash(const char *file, uint8_t *hash);
|
||||
int get_hash_algo(const char *algo);
|
||||
RSA *read_pub_key(const char *keyfile, int x509);
|
||||
|
||||
void calc_keyid_v1(uint8_t *keyid, char *str, const unsigned char *pkey, int len);
|
||||
void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key);
|
||||
int key2bin(RSA *key, unsigned char *pub);
|
||||
|
||||
int sign_hash(const char *algo, const unsigned char *hash, int size, const char *keyfile, const char *keypass, unsigned char *sig);
|
||||
int verify_hash(const unsigned char *hash, int size, unsigned char *sig, int siglen);
|
||||
int ima_verify_signature(const char *file, unsigned char *sig, int siglen);
|
||||
|
||||
#endif
|
813
src/libimaevm.c
Normal file
813
src/libimaevm.c
Normal file
@ -0,0 +1,813 @@
|
||||
/*
|
||||
* ima-evm-utils - IMA/EVM support utilities
|
||||
*
|
||||
* Copyright (C) 2011 Nokia Corporation
|
||||
* Copyright (C) 2011,2012,2013 Intel Corporation
|
||||
* Copyright (C) 2013,2014 Samsung Electronics
|
||||
*
|
||||
* Authors:
|
||||
* Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
|
||||
* <dmitry.kasatkin@intel.com>
|
||||
* <d.kasatkin@samsung.com>
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License
|
||||
* version 2 as published by the Free Software Foundation.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*
|
||||
* As a special exception, the copyright holders give permission to link the
|
||||
* code of portions of this program with the OpenSSL library under certain
|
||||
* conditions as described in each individual source file and distribute
|
||||
* linked combinations including the program with the OpenSSL library. You
|
||||
* must comply with the GNU General Public License in all respects
|
||||
* for all of the code used other than as permitted herein. If you modify
|
||||
* file(s) with this exception, you may extend this exception to your
|
||||
* version of the file(s), but you are not obligated to do so. If you do not
|
||||
* wish to do so, delete this exception statement from your version. If you
|
||||
* delete this exception statement from all source files in the program,
|
||||
* then also delete it in the license file.
|
||||
*
|
||||
* File: libimaevm.c
|
||||
* IMA/EVM library
|
||||
*/
|
||||
|
||||
/* should we use logger instead for library? */
|
||||
#define USE_FPRINTF
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <sys/param.h>
|
||||
#include <sys/stat.h>
|
||||
#include <asm/byteorder.h>
|
||||
#include <unistd.h>
|
||||
#include <dirent.h>
|
||||
#include <string.h>
|
||||
#include <stdio.h>
|
||||
|
||||
#include <openssl/pem.h>
|
||||
#include <openssl/evp.h>
|
||||
#include <openssl/x509.h>
|
||||
#include <openssl/err.h>
|
||||
|
||||
#include "imaevm.h"
|
||||
|
||||
const char *const pkey_hash_algo[PKEY_HASH__LAST] = {
|
||||
[PKEY_HASH_MD4] = "md4",
|
||||
[PKEY_HASH_MD5] = "md5",
|
||||
[PKEY_HASH_SHA1] = "sha1",
|
||||
[PKEY_HASH_RIPE_MD_160] = "rmd160",
|
||||
[PKEY_HASH_SHA256] = "sha256",
|
||||
[PKEY_HASH_SHA384] = "sha384",
|
||||
[PKEY_HASH_SHA512] = "sha512",
|
||||
[PKEY_HASH_SHA224] = "sha224",
|
||||
};
|
||||
|
||||
/*
|
||||
* Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
|
||||
*/
|
||||
static const uint8_t RSA_digest_info_MD5[] = {
|
||||
0x30, 0x20, 0x30, 0x0C, 0x06, 0x08,
|
||||
0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, /* OID */
|
||||
0x05, 0x00, 0x04, 0x10
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_SHA1[] = {
|
||||
0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
||||
0x2B, 0x0E, 0x03, 0x02, 0x1A,
|
||||
0x05, 0x00, 0x04, 0x14
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_RIPE_MD_160[] = {
|
||||
0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
|
||||
0x2B, 0x24, 0x03, 0x02, 0x01,
|
||||
0x05, 0x00, 0x04, 0x14
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_SHA224[] = {
|
||||
0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
|
||||
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
|
||||
0x05, 0x00, 0x04, 0x1C
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_SHA256[] = {
|
||||
0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
|
||||
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
|
||||
0x05, 0x00, 0x04, 0x20
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_SHA384[] = {
|
||||
0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
|
||||
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
|
||||
0x05, 0x00, 0x04, 0x30
|
||||
};
|
||||
|
||||
static const uint8_t RSA_digest_info_SHA512[] = {
|
||||
0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
|
||||
0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
|
||||
0x05, 0x00, 0x04, 0x40
|
||||
};
|
||||
|
||||
const struct RSA_ASN1_template RSA_ASN1_templates[PKEY_HASH__LAST] = {
|
||||
#define _(X) { RSA_digest_info_##X, sizeof(RSA_digest_info_##X) }
|
||||
[PKEY_HASH_MD5] = _(MD5),
|
||||
[PKEY_HASH_SHA1] = _(SHA1),
|
||||
[PKEY_HASH_RIPE_MD_160] = _(RIPE_MD_160),
|
||||
[PKEY_HASH_SHA256] = _(SHA256),
|
||||
[PKEY_HASH_SHA384] = _(SHA384),
|
||||
[PKEY_HASH_SHA512] = _(SHA512),
|
||||
[PKEY_HASH_SHA224] = _(SHA224),
|
||||
#undef _
|
||||
};
|
||||
|
||||
struct libevm_params params = {
|
||||
.verbose = LOG_INFO - 1,
|
||||
.x509 = 1,
|
||||
.hash_algo = "sha1",
|
||||
};
|
||||
|
||||
static void __attribute__ ((constructor)) libinit(void);
|
||||
|
||||
void do_dump(FILE *fp, const void *ptr, int len, bool cr)
|
||||
{
|
||||
int i;
|
||||
uint8_t *data = (uint8_t *) ptr;
|
||||
|
||||
for (i = 0; i < len; i++)
|
||||
fprintf(fp, "%02x", data[i]);
|
||||
if (cr)
|
||||
fprintf(fp, "\n");
|
||||
}
|
||||
|
||||
void dump(const void *ptr, int len)
|
||||
{
|
||||
do_dump(stdout, ptr, len, true);
|
||||
}
|
||||
|
||||
int get_filesize(const char *filename)
|
||||
{
|
||||
struct stat stats;
|
||||
/* Need to know the file length */
|
||||
stat(filename, &stats);
|
||||
return (int)stats.st_size;
|
||||
}
|
||||
|
||||
static inline off_t get_fdsize(int fd)
|
||||
{
|
||||
struct stat stats;
|
||||
/* Need to know the file length */
|
||||
fstat(fd, &stats);
|
||||
return stats.st_size;
|
||||
}
|
||||
|
||||
static int add_file_hash(const char *file, EVP_MD_CTX *ctx)
|
||||
{
|
||||
uint8_t *data;
|
||||
int err = -1, bs = DATA_SIZE;
|
||||
off_t size, len;
|
||||
FILE *fp;
|
||||
|
||||
fp = fopen(file, "r");
|
||||
if (!fp) {
|
||||
log_err("Failed to open: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
data = malloc(bs);
|
||||
if (!data) {
|
||||
log_err("malloc failed\n");
|
||||
goto out;
|
||||
}
|
||||
|
||||
for (size = get_fdsize(fileno(fp)); size; size -= len) {
|
||||
len = MIN(size, bs);
|
||||
if (!fread(data, len, 1, fp)) {
|
||||
if (ferror(fp)) {
|
||||
log_err("fread() failed\n\n");
|
||||
goto out;
|
||||
}
|
||||
break;
|
||||
}
|
||||
if (!EVP_DigestUpdate(ctx, data, len)) {
|
||||
log_err("EVP_DigestUpdate() failed\n");
|
||||
err = 1;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
err = 0;
|
||||
out:
|
||||
fclose(fp);
|
||||
free(data);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int add_dir_hash(const char *file, EVP_MD_CTX *ctx)
|
||||
{
|
||||
int err;
|
||||
struct dirent *de;
|
||||
DIR *dir;
|
||||
unsigned long long ino, off;
|
||||
unsigned int type;
|
||||
int result = 0;
|
||||
|
||||
dir = opendir(file);
|
||||
if (!dir) {
|
||||
log_err("Failed to open: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
while ((de = readdir(dir))) {
|
||||
ino = de->d_ino;
|
||||
off = de->d_off;
|
||||
type = de->d_type;
|
||||
log_debug("entry: %s, ino: %llu, type: %u, off: %llu, reclen: %hu\n",
|
||||
de->d_name, ino, type, off, de->d_reclen);
|
||||
err = EVP_DigestUpdate(ctx, de->d_name, strlen(de->d_name));
|
||||
/*err |= EVP_DigestUpdate(ctx, &off, sizeof(off));*/
|
||||
err |= EVP_DigestUpdate(ctx, &ino, sizeof(ino));
|
||||
err |= EVP_DigestUpdate(ctx, &type, sizeof(type));
|
||||
if (!err) {
|
||||
log_err("EVP_DigestUpdate() failed\n");
|
||||
result = 1;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
closedir(dir);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
static int add_link_hash(const char *path, EVP_MD_CTX *ctx)
|
||||
{
|
||||
int err;
|
||||
char buf[1024];
|
||||
|
||||
err = readlink(path, buf, sizeof(buf));
|
||||
if (err <= 0)
|
||||
return -1;
|
||||
|
||||
log_info("link: %s -> %.*s\n", path, err, buf);
|
||||
return !EVP_DigestUpdate(ctx, buf, err);
|
||||
}
|
||||
|
||||
static int add_dev_hash(struct stat *st, EVP_MD_CTX *ctx)
|
||||
{
|
||||
uint32_t dev = st->st_rdev;
|
||||
unsigned major = (dev & 0xfff00) >> 8;
|
||||
unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
|
||||
|
||||
log_info("device: %u:%u\n", major, minor);
|
||||
return !EVP_DigestUpdate(ctx, &dev, sizeof(dev));
|
||||
}
|
||||
|
||||
int ima_calc_hash(const char *file, uint8_t *hash)
|
||||
{
|
||||
const EVP_MD *md;
|
||||
struct stat st;
|
||||
EVP_MD_CTX ctx;
|
||||
unsigned int mdlen;
|
||||
int err;
|
||||
|
||||
/* Need to know the file length */
|
||||
err = lstat(file, &st);
|
||||
if (err < 0) {
|
||||
log_err("Failed to stat: %s\n", file);
|
||||
return err;
|
||||
}
|
||||
|
||||
md = EVP_get_digestbyname(params.hash_algo);
|
||||
if (!md) {
|
||||
log_err("EVP_get_digestbyname() failed\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
err = EVP_DigestInit(&ctx, md);
|
||||
if (!err) {
|
||||
log_err("EVP_DigestInit() failed\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
switch (st.st_mode & S_IFMT) {
|
||||
case S_IFREG:
|
||||
err = add_file_hash(file, &ctx);
|
||||
break;
|
||||
case S_IFDIR:
|
||||
err = add_dir_hash(file, &ctx);
|
||||
break;
|
||||
case S_IFLNK:
|
||||
err = add_link_hash(file, &ctx);
|
||||
break;
|
||||
case S_IFIFO: case S_IFSOCK:
|
||||
case S_IFCHR: case S_IFBLK:
|
||||
err = add_dev_hash(&st, &ctx);
|
||||
break;
|
||||
default:
|
||||
log_errno("Unsupported file type");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
err = EVP_DigestFinal(&ctx, hash, &mdlen);
|
||||
if (!err) {
|
||||
log_err("EVP_DigestFinal() failed\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
return mdlen;
|
||||
}
|
||||
|
||||
RSA *read_pub_key(const char *keyfile, int x509)
|
||||
{
|
||||
FILE *fp;
|
||||
RSA *key = NULL;
|
||||
X509 *crt = NULL;
|
||||
EVP_PKEY *pkey = NULL;
|
||||
|
||||
fp = fopen(keyfile, "r");
|
||||
if (!fp) {
|
||||
log_err("Failed to open keyfile: %s\n", keyfile);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
if (x509) {
|
||||
crt = d2i_X509_fp(fp, NULL);
|
||||
if (!crt) {
|
||||
log_err("d2i_X509_fp() failed\n");
|
||||
goto out;
|
||||
}
|
||||
pkey = X509_extract_key(crt);
|
||||
if (!pkey) {
|
||||
log_err("X509_extract_key() failed\n");
|
||||
goto out;
|
||||
}
|
||||
key = EVP_PKEY_get1_RSA(pkey);
|
||||
} else {
|
||||
key = PEM_read_RSA_PUBKEY(fp, NULL, NULL, NULL);
|
||||
}
|
||||
|
||||
if (!key)
|
||||
log_err("PEM_read_RSA_PUBKEY() failed\n");
|
||||
|
||||
out:
|
||||
if (pkey)
|
||||
EVP_PKEY_free(pkey);
|
||||
if (crt)
|
||||
X509_free(crt);
|
||||
fclose(fp);
|
||||
return key;
|
||||
}
|
||||
|
||||
int verify_hash_v1(const unsigned char *hash, int size, unsigned char *sig, int siglen, const char *keyfile)
|
||||
{
|
||||
int err, len;
|
||||
SHA_CTX ctx;
|
||||
unsigned char out[1024];
|
||||
RSA *key;
|
||||
unsigned char sighash[20];
|
||||
struct signature_hdr *hdr = (struct signature_hdr *)sig;
|
||||
|
||||
log_info("hash-v1: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_pub_key(keyfile, 0);
|
||||
if (!key)
|
||||
return 1;
|
||||
|
||||
SHA1_Init(&ctx);
|
||||
SHA1_Update(&ctx, hash, size);
|
||||
SHA1_Update(&ctx, hdr, sizeof(*hdr));
|
||||
SHA1_Final(sighash, &ctx);
|
||||
log_info("sighash: ");
|
||||
log_dump(sighash, sizeof(sighash));
|
||||
|
||||
err = RSA_public_decrypt(siglen - sizeof(*hdr) - 2, sig + sizeof(*hdr) + 2, out, key, RSA_PKCS1_PADDING);
|
||||
RSA_free(key);
|
||||
if (err < 0) {
|
||||
log_err("RSA_public_decrypt() failed: %d\n", err);
|
||||
return 1;
|
||||
}
|
||||
|
||||
len = err;
|
||||
|
||||
if (len != sizeof(sighash) || memcmp(out, sighash, len) != 0) {
|
||||
log_err("Verification failed: %d\n", err);
|
||||
return -1;
|
||||
} else {
|
||||
/*log_info("Verification is OK\n");*/
|
||||
printf("Verification is OK\n");
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int verify_hash_v2(const unsigned char *hash, int size, unsigned char *sig, int siglen, const char *keyfile)
|
||||
{
|
||||
int err, len;
|
||||
unsigned char out[1024];
|
||||
RSA *key;
|
||||
struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
|
||||
const struct RSA_ASN1_template *asn1;
|
||||
|
||||
log_info("hash: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_pub_key(keyfile, 1);
|
||||
if (!key)
|
||||
return 1;
|
||||
|
||||
err = RSA_public_decrypt(siglen - sizeof(*hdr), sig + sizeof(*hdr), out, key, RSA_PKCS1_PADDING);
|
||||
RSA_free(key);
|
||||
if (err < 0) {
|
||||
log_err("RSA_public_decrypt() failed: %d\n", err);
|
||||
return 1;
|
||||
}
|
||||
|
||||
len = err;
|
||||
|
||||
asn1 = &RSA_ASN1_templates[hdr->hash_algo];
|
||||
|
||||
if (len < asn1->size || memcmp(out, asn1->data, asn1->size)) {
|
||||
log_err("Verification failed: %d\n", err);
|
||||
return -1;
|
||||
}
|
||||
|
||||
len -= asn1->size;
|
||||
|
||||
if (len != size || memcmp(out + asn1->size, hash, len)) {
|
||||
log_err("Verification failed: %d\n", err);
|
||||
return -1;
|
||||
}
|
||||
|
||||
/*log_info("Verification is OK\n");*/
|
||||
printf("Verification is OK\n");
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int get_hash_algo(const char *algo)
|
||||
{
|
||||
int i;
|
||||
|
||||
for (i = 0; i < PKEY_HASH__LAST; i++)
|
||||
if (!strcmp(algo, pkey_hash_algo[i]))
|
||||
return i;
|
||||
|
||||
return PKEY_HASH_SHA1;
|
||||
}
|
||||
|
||||
static int get_hash_algo_from_sig(unsigned char *sig)
|
||||
{
|
||||
uint8_t hashalgo;
|
||||
|
||||
if (sig[0] == 1) {
|
||||
hashalgo = ((struct signature_hdr *)sig)->hash;
|
||||
|
||||
if (hashalgo >= DIGEST_ALGO_MAX)
|
||||
return -1;
|
||||
|
||||
switch (hashalgo) {
|
||||
case DIGEST_ALGO_SHA1:
|
||||
return PKEY_HASH_SHA1;
|
||||
case DIGEST_ALGO_SHA256:
|
||||
return PKEY_HASH_SHA256;
|
||||
default:
|
||||
return -1;
|
||||
}
|
||||
} else if (sig[0] == 2) {
|
||||
hashalgo = ((struct signature_v2_hdr *)sig)->hash_algo;
|
||||
if (hashalgo >= PKEY_HASH__LAST)
|
||||
return -1;
|
||||
return hashalgo;
|
||||
} else
|
||||
return -1;
|
||||
}
|
||||
|
||||
int verify_hash(const unsigned char *hash, int size, unsigned char *sig, int siglen)
|
||||
{
|
||||
const char *key;
|
||||
int x509;
|
||||
verify_hash_fn_t verify_hash;
|
||||
|
||||
/* Get signature type from sig header */
|
||||
if (sig[0] == DIGSIG_VERSION_1) {
|
||||
verify_hash = verify_hash_v1;
|
||||
/* Read pubkey from RSA key */
|
||||
x509 = 0;
|
||||
} else if (sig[0] == DIGSIG_VERSION_2) {
|
||||
verify_hash = verify_hash_v2;
|
||||
/* Read pubkey from x509 cert */
|
||||
x509 = 1;
|
||||
} else
|
||||
return -1;
|
||||
|
||||
/* Determine what key to use for verification*/
|
||||
key = params.keyfile ? : x509 ?
|
||||
"/etc/keys/x509_evm.der" :
|
||||
"/etc/keys/pubkey_evm.pem";
|
||||
|
||||
return verify_hash(hash, size, sig, siglen, key);
|
||||
}
|
||||
|
||||
int ima_verify_signature(const char *file, unsigned char *sig, int siglen)
|
||||
{
|
||||
unsigned char hash[64];
|
||||
int hashlen, sig_hash_algo;
|
||||
|
||||
if (sig[0] != 0x03) {
|
||||
log_err("security.ima has no signature\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
sig_hash_algo = get_hash_algo_from_sig(sig + 1);
|
||||
if (sig_hash_algo < 0) {
|
||||
log_err("Invalid signature\n");
|
||||
return -1;
|
||||
}
|
||||
/* Use hash algorithm as retrieved from signature */
|
||||
params.hash_algo = pkey_hash_algo[sig_hash_algo];
|
||||
|
||||
hashlen = ima_calc_hash(file, hash);
|
||||
if (hashlen <= 1)
|
||||
return hashlen;
|
||||
|
||||
return verify_hash(hash, hashlen, sig + 1, siglen - 1);
|
||||
}
|
||||
|
||||
/*
|
||||
* Create binary key representation suitable for kernel
|
||||
*/
|
||||
int key2bin(RSA *key, unsigned char *pub)
|
||||
{
|
||||
int len, b, offset = 0;
|
||||
struct pubkey_hdr *pkh = (struct pubkey_hdr *)pub;
|
||||
|
||||
/* add key header */
|
||||
pkh->version = 1;
|
||||
pkh->timestamp = 0; /* PEM has no timestamp?? */
|
||||
pkh->algo = PUBKEY_ALGO_RSA;
|
||||
pkh->nmpi = 2;
|
||||
|
||||
offset += sizeof(*pkh);
|
||||
|
||||
len = BN_num_bytes(key->n);
|
||||
b = BN_num_bits(key->n);
|
||||
pub[offset++] = b >> 8;
|
||||
pub[offset++] = b & 0xff;
|
||||
BN_bn2bin(key->n, &pub[offset]);
|
||||
offset += len;
|
||||
|
||||
len = BN_num_bytes(key->e);
|
||||
b = BN_num_bits(key->e);
|
||||
pub[offset++] = b >> 8;
|
||||
pub[offset++] = b & 0xff;
|
||||
BN_bn2bin(key->e, &pub[offset]);
|
||||
offset += len;
|
||||
|
||||
return offset;
|
||||
}
|
||||
|
||||
void calc_keyid_v1(uint8_t *keyid, char *str, const unsigned char *pkey, int len)
|
||||
{
|
||||
uint8_t sha1[SHA_DIGEST_LENGTH];
|
||||
uint64_t id;
|
||||
|
||||
SHA1(pkey, len, sha1);
|
||||
|
||||
/* sha1[12 - 19] is exactly keyid from gpg file */
|
||||
memcpy(keyid, sha1 + 12, 8);
|
||||
log_debug("keyid: ");
|
||||
log_debug_dump(keyid, 8);
|
||||
|
||||
id = __be64_to_cpup((__be64 *) keyid);
|
||||
sprintf(str, "%llX", (unsigned long long)id);
|
||||
log_info("keyid-v1: %s\n", str);
|
||||
}
|
||||
|
||||
void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
|
||||
{
|
||||
uint8_t sha1[SHA_DIGEST_LENGTH];
|
||||
unsigned char *pkey = NULL;
|
||||
int len;
|
||||
|
||||
len = i2d_RSAPublicKey(key, &pkey);
|
||||
|
||||
SHA1(pkey, len, sha1);
|
||||
|
||||
/* sha1[12 - 19] is exactly keyid from gpg file */
|
||||
memcpy(keyid, sha1 + 16, 4);
|
||||
log_debug("keyid: ");
|
||||
log_debug_dump(keyid, 4);
|
||||
|
||||
sprintf(str, "%x", __be32_to_cpup(keyid));
|
||||
log_info("keyid: %s\n", str);
|
||||
|
||||
free(pkey);
|
||||
}
|
||||
|
||||
static RSA *read_priv_key(const char *keyfile, const char *keypass)
|
||||
{
|
||||
FILE *fp;
|
||||
RSA *key;
|
||||
|
||||
fp = fopen(keyfile, "r");
|
||||
if (!fp) {
|
||||
log_err("Failed to open keyfile: %s\n", keyfile);
|
||||
return NULL;
|
||||
}
|
||||
ERR_load_crypto_strings();
|
||||
key = PEM_read_RSAPrivateKey(fp, NULL, NULL, (void *)keypass);
|
||||
if (!key) {
|
||||
char str[256];
|
||||
|
||||
ERR_error_string(ERR_get_error(), str);
|
||||
log_err("PEM_read_RSAPrivateKey() failed: %s\n", str);
|
||||
}
|
||||
|
||||
fclose(fp);
|
||||
return key;
|
||||
}
|
||||
|
||||
static int get_hash_algo_v1(const char *algo)
|
||||
{
|
||||
|
||||
if (!strcmp(algo, "sha1"))
|
||||
return DIGEST_ALGO_SHA1;
|
||||
else if (!strcmp(algo, "sha256"))
|
||||
return DIGEST_ALGO_SHA256;
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
int sign_hash_v1(const char *hashalgo, const unsigned char *hash, int size, const char *keyfile, unsigned char *sig)
|
||||
{
|
||||
int len = -1, hashalgo_idx;
|
||||
SHA_CTX ctx;
|
||||
unsigned char pub[1024];
|
||||
RSA *key;
|
||||
char name[20];
|
||||
unsigned char sighash[20];
|
||||
struct signature_hdr *hdr;
|
||||
uint16_t *blen;
|
||||
|
||||
if (!hash) {
|
||||
log_err("sign_hash_v1: hash is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (size < 0) {
|
||||
log_err("sign_hash_v1: size is negative: %d\n", size);
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (!hashalgo) {
|
||||
log_err("sign_hash_v1: hashalgo is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (!sig) {
|
||||
log_err("sign_hash_v1: sig is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_info("hash: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_priv_key(keyfile, params.keypass);
|
||||
if (!key)
|
||||
return -1;
|
||||
|
||||
hdr = (struct signature_hdr *)sig;
|
||||
|
||||
/* now create a new hash */
|
||||
hdr->version = (uint8_t) DIGSIG_VERSION_1;
|
||||
hdr->timestamp = time(NULL);
|
||||
hdr->algo = PUBKEY_ALGO_RSA;
|
||||
hashalgo_idx = get_hash_algo_v1(hashalgo);
|
||||
if (hashalgo_idx < 0) {
|
||||
log_err("Signature version 1 does not support hash algo %s\n",
|
||||
hashalgo);
|
||||
goto out;
|
||||
}
|
||||
hdr->hash = (uint8_t) hashalgo_idx;
|
||||
|
||||
len = key2bin(key, pub);
|
||||
calc_keyid_v1(hdr->keyid, name, pub, len);
|
||||
|
||||
hdr->nmpi = 1;
|
||||
|
||||
SHA1_Init(&ctx);
|
||||
SHA1_Update(&ctx, hash, size);
|
||||
SHA1_Update(&ctx, hdr, sizeof(*hdr));
|
||||
SHA1_Final(sighash, &ctx);
|
||||
log_info("sighash: ");
|
||||
log_dump(sighash, sizeof(sighash));
|
||||
|
||||
len = RSA_private_encrypt(sizeof(sighash), sighash, sig + sizeof(*hdr) + 2, key, RSA_PKCS1_PADDING);
|
||||
if (len < 0) {
|
||||
log_err("RSA_private_encrypt() failed: %d\n", len);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* we add bit length of the signature to make it gnupg compatible */
|
||||
blen = (uint16_t *) (sig + sizeof(*hdr));
|
||||
*blen = __cpu_to_be16(len << 3);
|
||||
len += sizeof(*hdr) + 2;
|
||||
log_info("evm/ima signature-v1: %d bytes\n", len);
|
||||
out:
|
||||
RSA_free(key);
|
||||
return len;
|
||||
}
|
||||
|
||||
int sign_hash_v2(const char *algo, const unsigned char *hash, int size, const char *keyfile, unsigned char *sig)
|
||||
{
|
||||
struct signature_v2_hdr *hdr;
|
||||
int len = -1;
|
||||
RSA *key;
|
||||
char name[20];
|
||||
unsigned char *buf;
|
||||
const struct RSA_ASN1_template *asn1;
|
||||
|
||||
if (!hash) {
|
||||
log_err("sign_hash_v2: hash is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (size < 0) {
|
||||
log_err("sign_hash_v2: size is negative: %d\n", size);
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (!sig) {
|
||||
log_err("sign_hash_v2: sig is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (!algo) {
|
||||
log_err("sign_hash_v2: algo is null\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
log_info("hash: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_priv_key(keyfile, params.keypass);
|
||||
if (!key)
|
||||
return -1;
|
||||
|
||||
hdr = (struct signature_v2_hdr *)sig;
|
||||
hdr->version = (uint8_t) DIGSIG_VERSION_2;
|
||||
|
||||
hdr->hash_algo = get_hash_algo(algo);
|
||||
|
||||
calc_keyid_v2(&hdr->keyid, name, key);
|
||||
|
||||
asn1 = &RSA_ASN1_templates[hdr->hash_algo];
|
||||
|
||||
buf = malloc(size + asn1->size);
|
||||
if (!buf)
|
||||
goto out;
|
||||
|
||||
memcpy(buf, asn1->data, asn1->size);
|
||||
memcpy(buf + asn1->size, hash, size);
|
||||
len = RSA_private_encrypt(size + asn1->size, buf, hdr->sig,
|
||||
key, RSA_PKCS1_PADDING);
|
||||
if (len < 0) {
|
||||
log_err("RSA_private_encrypt() failed: %d\n", len);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* we add bit length of the signature to make it gnupg compatible */
|
||||
hdr->sig_size = __cpu_to_be16(len);
|
||||
len += sizeof(*hdr);
|
||||
log_info("evm/ima signature: %d bytes\n", len);
|
||||
out:
|
||||
if (buf)
|
||||
free(buf);
|
||||
RSA_free(key);
|
||||
return len;
|
||||
}
|
||||
|
||||
|
||||
int sign_hash(const char *hashalgo, const unsigned char *hash, int size, const char *keyfile, const char *keypass, unsigned char *sig)
|
||||
{
|
||||
if (keypass)
|
||||
params.keypass = keypass;
|
||||
|
||||
return params.x509 ? sign_hash_v2(hashalgo, hash, size, keyfile, sig) :
|
||||
sign_hash_v1(hashalgo, hash, size, keyfile, sig);
|
||||
}
|
||||
|
||||
static void libinit()
|
||||
{
|
||||
OpenSSL_add_all_algorithms();
|
||||
ERR_load_crypto_strings();
|
||||
}
|
Loading…
x
Reference in New Issue
Block a user