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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
|
||||
|
@ -1,3 +1,12 @@
|
||||
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
|
||||
|
22
Makefile.am
22
Makefile.am
@ -1,6 +1,10 @@
|
||||
SUBDIRS = src
|
||||
dist_man_MANS = evmctl.1
|
||||
|
||||
EXTRA_DIST = autogen.sh
|
||||
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)
|
||||
|
462
README
462
README
@ -1,49 +1,187 @@
|
||||
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. In this version default UUID is included by
|
||||
default. Custom value can be supplied via '--uuid=UUID' or '-uUUID' parameter
|
||||
to the 'sign' command. To use old format HMAC format use '-' as a parameter.
|
||||
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. This version uses x509 format by default.
|
||||
Use '--rsa' or '-1' parameter to use old signature format and API.
|
||||
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 32" @u
|
||||
keyctl pipe `keyctl search @u encrypted evm-key` >/etc/keys/evm-key
|
||||
|
||||
$ openssl req -new -nodes -utf8 -sha1 -days 36500 -batch \
|
||||
-x509 -config x509_evm.genkey \
|
||||
-outform DER -out x509_evm.der -keyout privkey_evm.pem
|
||||
|
||||
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
|
||||
|
||||
Configuration file x509_evm.genkey:
|
||||
|
||||
@ -68,88 +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
|
||||
|
||||
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
|
||||
openssl rsa -pubout -in privkey_evm.pem -out pubkey_evm.pem
|
||||
|
||||
|
||||
Generation of EVM keys
|
||||
Copy keys to /etc/keys:
|
||||
|
||||
$ # create and save the kernel master key (user type)
|
||||
$ 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
|
||||
$ # create the EVM encrypted key
|
||||
$ keyctl add encrypted evm-key "new user:kmk 32" @u
|
||||
$ keyctl pipe `keyctl search @u encrypted evm-key` >/etc/keys/evm-key
|
||||
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
|
||||
|
||||
|
||||
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
|
||||
# mount securityfs if not mounted
|
||||
SECFS=/sys/kernel/security
|
||||
grep -q $SECFS /proc/mounts || mount -n -t securityfs securityfs $SECFS
|
||||
|
||||
# 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`
|
||||
fi
|
||||
fi
|
||||
# import IMA X509 certificate
|
||||
evmctl import /etc/keys/x509_ima.der $ima_id
|
||||
|
||||
# search for EVM keyring
|
||||
evm_id=`keyctl search @u keyring _evm 2>/dev/null`
|
||||
if [ -z "$evm_id" ]; then
|
||||
evm_id=`keyctl newring _evm @u`
|
||||
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
|
||||
|
||||
# import IMA public key
|
||||
ima_id=`keyctl newring _ima @u`
|
||||
evmctl --rsa import /etc/keys/pubkey_evm.pem $ima_id
|
||||
|
||||
# import EVM public key
|
||||
evm_id=`keyctl newring _evm @u`
|
||||
evmctl --rsa import /etc/keys/pubkey_evm.pem $evm_id
|
||||
# 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 import /etc/keys/x509_evm.der `keyctl search @u keyring _ima`
|
||||
$ evmctl 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 old RSA format is done using '-1' or '--rsa' parameter.
|
||||
Signing for using old 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] [-1] --imahash test.txt
|
||||
|
||||
Sign file with both IMA and EVM signatures - for immutable files
|
||||
|
||||
$ evmctl sign [-u] [-1] --imasig test.txt
|
||||
|
||||
Sign file with IMA signature - for immutable files
|
||||
|
||||
$ evmctl ima_sign [-1] test.txt
|
||||
|
||||
Label whole filesystem with EVM signatures
|
||||
|
||||
$ find / \( -fstype rootfs -o -fstype ext4 \) -exec evmctl sign [-u] [-1] --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).
|
||||
|
||||
|
@ -1,7 +1,7 @@
|
||||
# autoconf script
|
||||
|
||||
AC_PREREQ([2.65])
|
||||
AC_INIT(ima-evm-utils, 0.8, d.kasatkin@samsung.com)
|
||||
AC_INIT(ima-evm-utils, 0.9, d.kasatkin@samsung.com)
|
||||
AM_INIT_AUTOMAKE
|
||||
AC_CONFIG_HEADERS([config.h])
|
||||
AC_CONFIG_MACRO_DIR([m4])
|
||||
|
@ -1,5 +1,5 @@
|
||||
Name: ima-evm-utils
|
||||
Version: 0.8
|
||||
Version: 0.9
|
||||
Release: 1%{?dist}
|
||||
Summary: ima-evm-utils - IMA/EVM control utility
|
||||
Group: System/Libraries
|
||||
|
496
src/evmctl.c
496
src/evmctl.c
@ -50,9 +50,9 @@
|
||||
#include <string.h>
|
||||
#include <dirent.h>
|
||||
#include <attr/xattr.h>
|
||||
#include <linux/xattr.h>
|
||||
#include <getopt.h>
|
||||
#include <keyutils.h>
|
||||
#include <asm/byteorder.h>
|
||||
#include <ctype.h>
|
||||
|
||||
#include <openssl/sha.h>
|
||||
@ -65,14 +65,27 @@
|
||||
|
||||
#include "imaevm.h"
|
||||
|
||||
static char *evm_config_xattrnames[] = {
|
||||
"security.selinux",
|
||||
"security.SMACK64",
|
||||
"security.ima",
|
||||
"security.capability",
|
||||
static char *evm_default_xattrs[] = {
|
||||
XATTR_NAME_SELINUX,
|
||||
XATTR_NAME_SMACK,
|
||||
XATTR_NAME_IMA,
|
||||
XATTR_NAME_CAPS,
|
||||
NULL
|
||||
};
|
||||
|
||||
static char *evm_extra_smack_xattrs[] = {
|
||||
XATTR_NAME_SELINUX,
|
||||
XATTR_NAME_SMACK,
|
||||
XATTR_NAME_SMACKEXEC,
|
||||
XATTR_NAME_SMACKTRANSMUTE,
|
||||
XATTR_NAME_SMACKMMAP,
|
||||
XATTR_NAME_IMA,
|
||||
XATTR_NAME_CAPS,
|
||||
NULL
|
||||
};
|
||||
|
||||
static char **evm_config_xattrnames = evm_default_xattrs;
|
||||
|
||||
struct command {
|
||||
char *name;
|
||||
int (*func)(struct command *cmd);
|
||||
@ -84,18 +97,21 @@ struct command {
|
||||
static int g_argc;
|
||||
static char **g_argv;
|
||||
static int xattr = 1;
|
||||
static bool check_xattr;
|
||||
static int sigdump;
|
||||
static int digest;
|
||||
static int digsig;
|
||||
static char *keypass;
|
||||
static int sigfile;
|
||||
static int x509 = 1;
|
||||
static char *uuid_str = "+";
|
||||
static char *uuid_str;
|
||||
static char *search_type;
|
||||
static int recursive;
|
||||
static int msize;
|
||||
static dev_t fs_dev;
|
||||
|
||||
#define HMAC_FLAG_UUID 0x0001
|
||||
#define HMAC_FLAG_UUID_SET 0x0002
|
||||
static unsigned long hmac_flags = HMAC_FLAG_UUID;
|
||||
|
||||
typedef int (*find_cb_t)(const char *path);
|
||||
static int find(const char *path, int dts, find_cb_t func);
|
||||
|
||||
@ -105,10 +121,6 @@ static int find(const char *path, int dts, find_cb_t func);
|
||||
#define CHR_MASK (1 << DT_CHR)
|
||||
#define BLK_MASK (1 << DT_BLK)
|
||||
|
||||
typedef int (*sign_hash_fn_t)(const char *algo, const unsigned char *hash, int size, const char *keyfile, unsigned char *sig);
|
||||
|
||||
static sign_hash_fn_t sign_hash;
|
||||
|
||||
struct command cmds[];
|
||||
static void print_usage(struct command *cmd);
|
||||
|
||||
@ -127,7 +139,7 @@ static int bin2file(const char *file, const char *ext, const unsigned char *data
|
||||
|
||||
fp = fopen(name, "w");
|
||||
if (!fp) {
|
||||
log_err("Unable to open %s for writing\n", name);
|
||||
log_err("Failed to open: %s\n", name);
|
||||
return -1;
|
||||
}
|
||||
err = fwrite(data, len, 1, fp);
|
||||
@ -152,7 +164,7 @@ static unsigned char *file2bin(const char *file, const char *ext, int *size)
|
||||
len = get_filesize(name);
|
||||
fp = fopen(name, "r");
|
||||
if (!fp) {
|
||||
log_err("Unable to open %s\n", name);
|
||||
log_err("Failed to open: %s\n", name);
|
||||
return NULL;
|
||||
}
|
||||
data = malloc(len);
|
||||
@ -164,215 +176,6 @@ static unsigned char *file2bin(const char *file, const char *ext, int *size)
|
||||
return data;
|
||||
}
|
||||
|
||||
/*
|
||||
* Create binary key representation suitable for kernel
|
||||
*/
|
||||
static 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;
|
||||
}
|
||||
|
||||
static 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: %s\n", str);
|
||||
}
|
||||
|
||||
static 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)
|
||||
{
|
||||
FILE *fp;
|
||||
RSA *key;
|
||||
|
||||
fp = fopen(keyfile, "r");
|
||||
if (!fp) {
|
||||
log_err("Unable to open keyfile %s\n", keyfile);
|
||||
return NULL;
|
||||
}
|
||||
key = PEM_read_RSAPrivateKey(fp, NULL, NULL, keypass);
|
||||
if (!key)
|
||||
log_err("PEM_read_RSAPrivateKey() failed\n");
|
||||
|
||||
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;
|
||||
}
|
||||
|
||||
static 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 = (struct signature_hdr *)sig;
|
||||
uint16_t *blen;
|
||||
|
||||
log_info("hash: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_priv_key(keyfile);
|
||||
if (!key)
|
||||
return -1;
|
||||
|
||||
/* 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: %d bytes\n", len);
|
||||
if (sigdump || params.verbose >= LOG_INFO)
|
||||
dump(sig, len);
|
||||
out:
|
||||
RSA_free(key);
|
||||
return len;
|
||||
}
|
||||
|
||||
static int sign_hash_v2(const char *algo, const unsigned char *hash, int size, const char *keyfile, unsigned char *sig)
|
||||
{
|
||||
struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
|
||||
int len = -1;
|
||||
RSA *key;
|
||||
char name[20];
|
||||
unsigned char *buf;
|
||||
const struct RSA_ASN1_template *asn1;
|
||||
|
||||
log_info("hash: ");
|
||||
log_dump(hash, size);
|
||||
|
||||
key = read_priv_key(keyfile);
|
||||
if (!key)
|
||||
return -1;
|
||||
|
||||
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);
|
||||
if (sigdump || params.verbose >= LOG_INFO)
|
||||
dump(sig, len);
|
||||
out:
|
||||
if (buf)
|
||||
free(buf);
|
||||
RSA_free(key);
|
||||
return len;
|
||||
}
|
||||
|
||||
static int find_xattr(const char *list, int list_size, const char *xattr)
|
||||
{
|
||||
int len;
|
||||
@ -470,7 +273,7 @@ static int get_uuid(struct stat *st, char *uuid)
|
||||
FILE *fp;
|
||||
size_t len;
|
||||
|
||||
if (uuid_str[0] != '+')
|
||||
if (hmac_flags & HMAC_FLAG_UUID_SET)
|
||||
return pack_uuid(uuid_str, uuid);
|
||||
|
||||
dev = st->st_dev;
|
||||
@ -481,19 +284,18 @@ static int get_uuid(struct stat *st, char *uuid)
|
||||
sprintf(path, "blkid -s UUID -o value /dev/block/%u:%u", major, minor);
|
||||
|
||||
fp = popen(path, "r");
|
||||
if (!fp) {
|
||||
log_err("popen() failed\n");
|
||||
return -1;
|
||||
}
|
||||
if (!fp)
|
||||
goto err;
|
||||
|
||||
len = fread(_uuid, 1, sizeof(_uuid), fp);
|
||||
pclose(fp);
|
||||
if (len != sizeof(_uuid)) {
|
||||
log_err("fread() failed\n");
|
||||
return -1;
|
||||
}
|
||||
if (len != sizeof(_uuid))
|
||||
goto err;
|
||||
|
||||
return pack_uuid(_uuid, uuid);
|
||||
err:
|
||||
log_err("Failed to read UUID. Root access might require.\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
@ -512,7 +314,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
int hmac_size;
|
||||
|
||||
if (lstat(file, &st)) {
|
||||
log_err("lstat() failed\n");
|
||||
log_err("Failed to stat: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -520,11 +322,12 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
/* we cannot at the momement to get generation of special files..
|
||||
* kernel API does not support it */
|
||||
int fd = open(file, 0);
|
||||
|
||||
if (fd < 0) {
|
||||
log_err("Unable to open %s\n", file);
|
||||
log_err("Failed to open: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
if (ioctl(fd, EXT34_IOC_GETVERSION, &generation)) {
|
||||
if (ioctl(fd, FS_IOC_GETVERSION, &generation)) {
|
||||
log_err("ioctl() failed\n");
|
||||
return -1;
|
||||
}
|
||||
@ -569,6 +372,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
|
||||
if (msize == 0) {
|
||||
struct h_misc *hmac = (struct h_misc *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -577,6 +381,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
hmac->mode = st.st_mode;
|
||||
} else if (msize == 64) {
|
||||
struct h_misc_64 *hmac = (struct h_misc_64 *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -585,6 +390,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
hmac->mode = st.st_mode;
|
||||
} else {
|
||||
struct h_misc_32 *hmac = (struct h_misc_32 *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -602,7 +408,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
return 1;
|
||||
}
|
||||
|
||||
if (*uuid_str != '-') {
|
||||
if (hmac_flags & HMAC_FLAG_UUID) {
|
||||
err = get_uuid(&st, uuid);
|
||||
if (err)
|
||||
return -1;
|
||||
@ -626,7 +432,7 @@ static int calc_evm_hash(const char *file, unsigned char *hash)
|
||||
static int sign_evm(const char *file, const char *key)
|
||||
{
|
||||
unsigned char hash[20];
|
||||
unsigned char sig[1024] = "\x03";
|
||||
unsigned char sig[1024];
|
||||
int len, err;
|
||||
|
||||
len = calc_evm_hash(file, hash);
|
||||
@ -637,8 +443,15 @@ static int sign_evm(const char *file, const char *key)
|
||||
if (len <= 1)
|
||||
return len;
|
||||
|
||||
/* add header */
|
||||
len++;
|
||||
sig[0] = EVM_IMA_XATTR_DIGSIG;
|
||||
|
||||
if (sigdump || params.verbose >= LOG_INFO)
|
||||
dump(sig, len);
|
||||
|
||||
if (xattr) {
|
||||
err = lsetxattr(file, "security.evm", sig, len + 1, 0);
|
||||
err = lsetxattr(file, "security.evm", sig, len, 0);
|
||||
if (err < 0) {
|
||||
log_err("setxattr failed: %s\n", file);
|
||||
return err;
|
||||
@ -650,21 +463,33 @@ static int sign_evm(const char *file, const char *key)
|
||||
|
||||
static int hash_ima(const char *file)
|
||||
{
|
||||
unsigned char hash[65] = "\x01"; /* MAX hash size + 1 */
|
||||
int len, err;
|
||||
unsigned char hash[66]; /* MAX hash size + 2 */
|
||||
int len, err, offset;
|
||||
int algo = get_hash_algo(params.hash_algo);
|
||||
|
||||
len = ima_calc_hash(file, hash + 1);
|
||||
if (algo > PKEY_HASH_SHA1) {
|
||||
hash[0] = IMA_XATTR_DIGEST_NG;
|
||||
hash[1] = algo;
|
||||
offset = 2;
|
||||
} else {
|
||||
hash[0] = IMA_XATTR_DIGEST;
|
||||
offset = 1;
|
||||
}
|
||||
|
||||
len = ima_calc_hash(file, hash + offset);
|
||||
if (len <= 1)
|
||||
return len;
|
||||
|
||||
len += offset;
|
||||
|
||||
if (params.verbose >= LOG_INFO)
|
||||
log_info("hash: ");
|
||||
|
||||
if (sigdump || params.verbose >= LOG_INFO)
|
||||
dump(hash, len + 1);
|
||||
dump(hash, len);
|
||||
|
||||
if (xattr) {
|
||||
err = lsetxattr(file, "security.ima", hash, len + 1, 0);
|
||||
err = lsetxattr(file, "security.ima", hash, len, 0);
|
||||
if (err < 0) {
|
||||
log_err("setxattr failed: %s\n", file);
|
||||
return err;
|
||||
@ -690,7 +515,7 @@ static int cmd_hash_ima(struct command *cmd)
|
||||
static int sign_ima(const char *file, const char *key)
|
||||
{
|
||||
unsigned char hash[64];
|
||||
unsigned char sig[1024] = "\x03";
|
||||
unsigned char sig[1024];
|
||||
int len, err;
|
||||
|
||||
len = ima_calc_hash(file, hash);
|
||||
@ -703,6 +528,10 @@ static int sign_ima(const char *file, const char *key)
|
||||
|
||||
/* add header */
|
||||
len++;
|
||||
sig[0] = EVM_IMA_XATTR_DIGSIG;
|
||||
|
||||
if (sigdump || params.verbose >= LOG_INFO)
|
||||
dump(sig, len);
|
||||
|
||||
if (sigfile)
|
||||
bin2file(file, "sig", sig, len);
|
||||
@ -731,11 +560,13 @@ static int get_file_type(const char *path, const char *search_type)
|
||||
dts |= DIR_MASK; break;
|
||||
case 's':
|
||||
dts |= BLK_MASK | CHR_MASK | LNK_MASK; break;
|
||||
case 'x':
|
||||
check_xattr = true; break;
|
||||
case 'm':
|
||||
/* stay within the same filesystem*/
|
||||
err = lstat(path, &st);
|
||||
if (err < 0) {
|
||||
log_err("stat() failed\n");
|
||||
log_err("Failed to stat: %s\n", path);
|
||||
return err;
|
||||
}
|
||||
fs_dev = st.st_dev; /* filesystem to start from */
|
||||
@ -882,12 +713,12 @@ static int verify_evm(const char *file)
|
||||
|
||||
len = lgetxattr(file, "security.evm", sig, sizeof(sig));
|
||||
if (len < 0) {
|
||||
log_err("getxattr failed\n");
|
||||
log_err("getxattr failed: %s\n", file);
|
||||
return len;
|
||||
}
|
||||
|
||||
if (sig[0] != 0x03) {
|
||||
log_err("security.evm has not signature\n");
|
||||
log_err("security.evm has no signature\n");
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -915,14 +746,14 @@ static int verify_ima(const char *file)
|
||||
if (xattr) {
|
||||
len = lgetxattr(file, "security.ima", sig, sizeof(sig));
|
||||
if (len < 0) {
|
||||
log_err("getxattr failed\n");
|
||||
log_err("getxattr failed: %s\n", file);
|
||||
return len;
|
||||
}
|
||||
}
|
||||
|
||||
if (sigfile) {
|
||||
void *tmp;
|
||||
tmp = file2bin(file, "sig", &len);
|
||||
void *tmp = file2bin(file, "sig", &len);
|
||||
|
||||
memcpy(sig, tmp, len);
|
||||
free(tmp);
|
||||
}
|
||||
@ -954,8 +785,8 @@ static int cmd_import(struct command *cmd)
|
||||
|
||||
inkey = g_argv[optind++];
|
||||
if (!inkey) {
|
||||
inkey = x509 ? "/etc/keys/x509_evm.der" :
|
||||
"/etc/keys/pubkey_evm.pem";
|
||||
inkey = params.x509 ? "/etc/keys/x509_evm.der" :
|
||||
"/etc/keys/pubkey_evm.pem";
|
||||
} else
|
||||
ring = g_argv[optind++];
|
||||
|
||||
@ -963,7 +794,11 @@ static int cmd_import(struct command *cmd)
|
||||
|
||||
if (ring) {
|
||||
if (ring[0] != '@') {
|
||||
id = atoi(ring);
|
||||
int base = 10;
|
||||
|
||||
if (ring[0] == '0' && ring[1] == 'x')
|
||||
base = 16;
|
||||
id = strtoul(ring, NULL, base);
|
||||
} else {
|
||||
if (strcmp(ring, "@t") == 0)
|
||||
id = -1;
|
||||
@ -980,11 +815,11 @@ static int cmd_import(struct command *cmd)
|
||||
}
|
||||
}
|
||||
|
||||
key = read_pub_key(inkey, x509);
|
||||
key = read_pub_key(inkey, params.x509);
|
||||
if (!key)
|
||||
return 1;
|
||||
|
||||
if (x509) {
|
||||
if (params.x509) {
|
||||
pub = file2bin(inkey, NULL, &len);
|
||||
if (!pub)
|
||||
goto out;
|
||||
@ -996,7 +831,7 @@ static int cmd_import(struct command *cmd)
|
||||
|
||||
log_info("Importing public key %s from file %s into keyring %d\n", name, inkey, id);
|
||||
|
||||
id = add_key(x509 ? "asymmetric" : "user", x509 ? NULL : name, pub, len, id);
|
||||
id = add_key(params.x509 ? "asymmetric" : "user", params.x509 ? NULL : name, pub, len, id);
|
||||
if (id < 0) {
|
||||
log_err("add_key failed\n");
|
||||
err = id;
|
||||
@ -1004,7 +839,7 @@ static int cmd_import(struct command *cmd)
|
||||
log_info("keyid: %d\n", id);
|
||||
printf("%d\n", id);
|
||||
}
|
||||
if (x509)
|
||||
if (params.x509)
|
||||
free(pub);
|
||||
out:
|
||||
RSA_free(key);
|
||||
@ -1032,12 +867,12 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
|
||||
key = file2bin(keyfile, NULL, &keylen);
|
||||
if (!key) {
|
||||
log_err("Unable to read a key: %s\n\n", keyfile);
|
||||
log_err("Failed to read a key: %s\n", keyfile);
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (keylen > sizeof(evmkey)) {
|
||||
log_err("key is too long\n");
|
||||
log_err("key is too long: %d\n", keylen);
|
||||
goto out;
|
||||
}
|
||||
|
||||
@ -1046,7 +881,7 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
memset(evmkey + keylen, 0, sizeof(evmkey) - keylen);
|
||||
|
||||
if (lstat(file, &st)) {
|
||||
log_err("lstat() failed\n");
|
||||
log_err("Failed to stat: %s\n", file);
|
||||
goto out;
|
||||
}
|
||||
|
||||
@ -1054,11 +889,12 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
/* we cannot at the momement to get generation of special files..
|
||||
* kernel API does not support it */
|
||||
int fd = open(file, 0);
|
||||
|
||||
if (fd < 0) {
|
||||
log_err("Unable to open %s\n", file);
|
||||
log_err("Failed to open %s\n", file);
|
||||
goto out;
|
||||
}
|
||||
if (ioctl(fd, EXT34_IOC_GETVERSION, &generation)) {
|
||||
if (ioctl(fd, FS_IOC_GETVERSION, &generation)) {
|
||||
log_err("ioctl() failed\n");
|
||||
goto out;
|
||||
}
|
||||
@ -1069,7 +905,7 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
|
||||
list_size = llistxattr(file, list, sizeof(list));
|
||||
if (list_size <= 0) {
|
||||
log_err("llistxattr() failed\n");
|
||||
log_err("llistxattr() failed: %s\n", file);
|
||||
goto out;
|
||||
}
|
||||
|
||||
@ -1103,6 +939,7 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
|
||||
if (msize == 0) {
|
||||
struct h_misc *hmac = (struct h_misc *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -1111,6 +948,7 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
hmac->mode = st.st_mode;
|
||||
} else if (msize == 64) {
|
||||
struct h_misc_64 *hmac = (struct h_misc_64 *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -1119,6 +957,7 @@ static int calc_evm_hmac(const char *file, const char *keyfile, unsigned char *h
|
||||
hmac->mode = st.st_mode;
|
||||
} else {
|
||||
struct h_misc_32 *hmac = (struct h_misc_32 *)&hmac_misc;
|
||||
|
||||
hmac_size = sizeof(*hmac);
|
||||
hmac->ino = st.st_ino;
|
||||
hmac->generation = generation;
|
||||
@ -1148,7 +987,7 @@ out:
|
||||
static int hmac_evm(const char *file, const char *key)
|
||||
{
|
||||
unsigned char hash[20];
|
||||
unsigned char sig[1024] = "\x02";
|
||||
unsigned char sig[1024];
|
||||
int len, err;
|
||||
|
||||
len = calc_evm_hmac(file, key, hash);
|
||||
@ -1160,6 +999,7 @@ static int hmac_evm(const char *file, const char *key)
|
||||
memcpy(sig + 1, hash, len);
|
||||
|
||||
if (xattr) {
|
||||
sig[0] = EVM_XATTR_HMAC;
|
||||
err = lsetxattr(file, "security.evm", sig, len + 1, 0);
|
||||
if (err < 0) {
|
||||
log_err("setxattr failed: %s\n", file);
|
||||
@ -1205,13 +1045,13 @@ static int ima_fix(const char *path)
|
||||
|
||||
log_info("%s\n", path);
|
||||
|
||||
if (xattr) {
|
||||
if (check_xattr) {
|
||||
/* re-measuring takes a time
|
||||
* in some cases we can skip labeling if xattrs exists
|
||||
*/
|
||||
size = llistxattr(path, list, sizeof(buf));
|
||||
if (size < 0) {
|
||||
log_errno("llistxattr() failed: %s\n", path);
|
||||
log_errno("Failed to read xattrs (llistxattr): %s\n", path);
|
||||
return -1;
|
||||
}
|
||||
for (; size > 0; len++, size -= len, list += len) {
|
||||
@ -1227,7 +1067,7 @@ static int ima_fix(const char *path)
|
||||
|
||||
fd = open(path, O_RDONLY);
|
||||
if (fd < 0) {
|
||||
log_errno("%s open failed", path);
|
||||
log_errno("Failed to open file: %s", path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -1244,8 +1084,9 @@ static int find(const char *path, int dts, find_cb_t func)
|
||||
if (fs_dev) {
|
||||
struct stat st;
|
||||
int err = lstat(path, &st);
|
||||
|
||||
if (err < 0) {
|
||||
log_err("stat() failed\n");
|
||||
log_err("Failed to stat: %s\n", path);
|
||||
return err;
|
||||
}
|
||||
if (st.st_dev != fs_dev)
|
||||
@ -1254,12 +1095,12 @@ static int find(const char *path, int dts, find_cb_t func)
|
||||
|
||||
dir = opendir(path);
|
||||
if (!dir) {
|
||||
log_err("Unable to open %s\n", path);
|
||||
log_err("Failed to open directory %s\n", path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
if (fchdir(dirfd(dir))) {
|
||||
log_err("Unable to chdir %s\n", path);
|
||||
log_err("Failed to chdir %s\n", path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -1274,7 +1115,7 @@ static int find(const char *path, int dts, find_cb_t func)
|
||||
}
|
||||
|
||||
if (chdir("..")) {
|
||||
log_err("Unable to chdir %s\n", path);
|
||||
log_err("Failed to chdir: %s\n", path);
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -1290,7 +1131,6 @@ static int cmd_ima_fix(struct command *cmd)
|
||||
{
|
||||
char *path = g_argv[optind++];
|
||||
int err, dts = REG_MASK; /* only regular files by default */
|
||||
struct stat st;
|
||||
|
||||
if (!path) {
|
||||
log_err("Parameters missing\n");
|
||||
@ -1298,41 +1138,18 @@ static int cmd_ima_fix(struct command *cmd)
|
||||
return -1;
|
||||
}
|
||||
|
||||
xattr = 0; /* do not check xattrs, fix everything */
|
||||
|
||||
if (search_type) {
|
||||
int i;
|
||||
|
||||
dts = 0;
|
||||
for (i = 0; search_type[i]; i++) {
|
||||
switch (search_type[i]) {
|
||||
case 'f':
|
||||
dts |= REG_MASK; break;
|
||||
case 'd':
|
||||
dts |= DIR_MASK; break;
|
||||
case 's':
|
||||
dts |= BLK_MASK | CHR_MASK | LNK_MASK; break;
|
||||
case 'x':
|
||||
/* check xattrs */
|
||||
xattr = 1; break;
|
||||
case 'm':
|
||||
/* stay within the same filesystem*/
|
||||
err = lstat(path, &st);
|
||||
if (err < 0) {
|
||||
log_err("stat() failed\n");
|
||||
return err;
|
||||
}
|
||||
fs_dev = st.st_dev; /* filesystem to start from */
|
||||
break;
|
||||
}
|
||||
if (recursive) {
|
||||
if (search_type) {
|
||||
dts = get_file_type(path, search_type);
|
||||
if (dts < 0)
|
||||
return dts;
|
||||
}
|
||||
err = find(path, dts, ima_fix);
|
||||
} else {
|
||||
err = ima_fix(path);
|
||||
}
|
||||
|
||||
err = find(path, dts, ima_fix);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
return 0;
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
@ -1492,7 +1309,7 @@ static int ima_measurement(const char *file)
|
||||
uint8_t pcr10[SHA_DIGEST_LENGTH];
|
||||
struct template_entry entry = { .template = 0 };
|
||||
FILE *fp;
|
||||
int err;
|
||||
int err = -1;
|
||||
|
||||
memset(fox, 0xff, SHA_DIGEST_LENGTH);
|
||||
|
||||
@ -1501,23 +1318,23 @@ static int ima_measurement(const char *file)
|
||||
|
||||
fp = fopen(file, "rb");
|
||||
if (!fp) {
|
||||
log_err("Unable to open measurement file\n");
|
||||
log_err("Failed to open measurement file: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
while ((err = fread(&entry.header, sizeof(entry.header), 1, fp))) {
|
||||
while (fread(&entry.header, sizeof(entry.header), 1, fp)) {
|
||||
ima_extend_pcr(pcr, entry.header.digest, SHA_DIGEST_LENGTH);
|
||||
|
||||
if (!fread(entry.name, entry.header.name_len, 1, fp)) {
|
||||
log_err("Unable to read template name\n");
|
||||
return -1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
entry.name[entry.header.name_len] = '\0';
|
||||
|
||||
if (!fread(&entry.template_len, sizeof(entry.template_len), 1, fp)) {
|
||||
log_err("Unable to read template length\n");
|
||||
return -1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (entry.template_buf_len < entry.template_len) {
|
||||
@ -1528,7 +1345,7 @@ static int ima_measurement(const char *file)
|
||||
|
||||
if (!fread(entry.template, entry.template_len, 1, fp)) {
|
||||
log_err("Unable to read template\n");
|
||||
return -1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
if (validate)
|
||||
@ -1540,8 +1357,6 @@ static int ima_measurement(const char *file)
|
||||
ima_ng_show(&entry);
|
||||
}
|
||||
|
||||
fclose(fp);
|
||||
|
||||
tpm_pcr_read(10, pcr10, sizeof(pcr10));
|
||||
|
||||
log_info("PCRAgg: ");
|
||||
@ -1552,10 +1367,14 @@ static int ima_measurement(const char *file)
|
||||
|
||||
if (memcmp(pcr, pcr10, sizeof(pcr))) {
|
||||
log_err("PCRAgg does not match PCR-10\n");
|
||||
return -1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
return 0;
|
||||
err = 0;
|
||||
out:
|
||||
fclose(fp);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int cmd_ima_measurement(struct command *cmd)
|
||||
@ -1642,26 +1461,28 @@ static void usage(void)
|
||||
printf(
|
||||
"\n"
|
||||
" -a, --hashalgo sha1 (default), sha224, sha256, sha384, sha512\n"
|
||||
" -s, --imasig also make IMA signature\n"
|
||||
" -d, --imahash also make IMA hash\n"
|
||||
" -s, --imasig make IMA signature\n"
|
||||
" -d, --imahash make IMA hash\n"
|
||||
" -f, --sigfile store IMA signature in .sig file instead of xattr\n"
|
||||
" -1, --rsa signing key is in RSA DER format (signing v1)\n"
|
||||
" -k, --key path to signing key (default keys are /etc/keys/{privkey,pubkey}_evm.pem)\n"
|
||||
" --rsa use RSA key type and signing scheme v1\n"
|
||||
" -k, --key path to signing key (default: /etc/keys/{privkey,pubkey}_evm.pem)\n"
|
||||
" -p, --pass password for encrypted signing key\n"
|
||||
" -u, --uuid use file system UUID in HMAC calculation (EVM v2)\n"
|
||||
" -t, --type file types to fix 'fdsxm' (f - file, d - directory, s - block/char/symlink)\n"
|
||||
" x - skip fixing if both ima and evm xattrs exist (caution: they may be wrong)\n"
|
||||
" -r, --recursive recurse into directories (sign)\n"
|
||||
" -t, --type file types to fix 'fdsxm' (f: file, d: directory, s: block/char/symlink)\n"
|
||||
" x - skip fixing if both ima and evm xattrs exist (use with caution)\n"
|
||||
" m - stay on the same filesystem (like 'find -xdev')\n"
|
||||
" -n print result to stdout instead of setting xattr\n"
|
||||
" -r, --recursive recurse into directories (sign)\n"
|
||||
" --m32 force signature for 32 bit target system\n"
|
||||
" --m64 force signature for 32 bit target system\n"
|
||||
" -u, --uuid use custom FS UUID for EVM (unspecified: from FS, empty: do not use)\n"
|
||||
" --smack use extra SMACK xattrs for EVM\n"
|
||||
" --m32 force EVM hmac/signature for 32 bit target system\n"
|
||||
" --m64 force EVM hmac/signature for 64 bit target system\n"
|
||||
" -v increase verbosity level\n"
|
||||
" -h, --help display this help and exit\n"
|
||||
"\n");
|
||||
}
|
||||
|
||||
struct command cmds[] = {
|
||||
{"--version", NULL, 0, ""},
|
||||
{"help", cmd_help, 0, "<command>"},
|
||||
{"import", cmd_import, 0, "[--rsa] pubkey keyring", "Import public key into the keyring.\n"},
|
||||
{"sign", cmd_sign_evm, 0, "[-r] [--imahash | --imasig ] [--key key] [--pass password] file", "Sign file metadata.\n"},
|
||||
@ -1692,6 +1513,8 @@ static struct option opts[] = {
|
||||
{"recursive", 0, 0, 'r'},
|
||||
{"m32", 0, 0, '3'},
|
||||
{"m64", 0, 0, '6'},
|
||||
{"smack", 0, 0, 256},
|
||||
{"version", 0, 0, 257},
|
||||
{}
|
||||
|
||||
};
|
||||
@ -1731,17 +1554,21 @@ int main(int argc, char *argv[])
|
||||
params.hash_algo = optarg;
|
||||
break;
|
||||
case 'p':
|
||||
keypass = optarg;
|
||||
params.keypass = optarg;
|
||||
break;
|
||||
case 'f':
|
||||
sigfile = 1;
|
||||
xattr = 0;
|
||||
break;
|
||||
case 'u':
|
||||
uuid_str = optarg ?: "+";
|
||||
uuid_str = optarg;
|
||||
if (uuid_str)
|
||||
hmac_flags |= HMAC_FLAG_UUID_SET;
|
||||
else
|
||||
hmac_flags &= ~HMAC_FLAG_UUID;
|
||||
break;
|
||||
case '1':
|
||||
x509 = 0;
|
||||
params.x509 = 0;
|
||||
break;
|
||||
case 'k':
|
||||
params.keyfile = optarg;
|
||||
@ -1758,6 +1585,13 @@ int main(int argc, char *argv[])
|
||||
case '6':
|
||||
msize = 64;
|
||||
break;
|
||||
case 256:
|
||||
evm_config_xattrnames = evm_extra_smack_xattrs;
|
||||
break;
|
||||
case 257:
|
||||
printf("evmctl %s\n", VERSION);
|
||||
exit(0);
|
||||
break;
|
||||
case '?':
|
||||
exit(1);
|
||||
break;
|
||||
@ -1766,11 +1600,6 @@ int main(int argc, char *argv[])
|
||||
}
|
||||
}
|
||||
|
||||
if (x509)
|
||||
sign_hash = sign_hash_v2;
|
||||
else
|
||||
sign_hash = sign_hash_v1;
|
||||
|
||||
OpenSSL_add_all_algorithms();
|
||||
ERR_load_crypto_strings();
|
||||
|
||||
@ -1781,6 +1610,7 @@ int main(int argc, char *argv[])
|
||||
|
||||
if (err) {
|
||||
unsigned long error;
|
||||
|
||||
if (errno)
|
||||
log_err("errno: %s (%d)\n", strerror(errno), errno);
|
||||
for (;;) {
|
||||
|
23
src/imaevm.h
23
src/imaevm.h
@ -41,6 +41,7 @@
|
||||
#ifndef _LIBIMAEVM_H
|
||||
#define _LIBIMAEVM_H
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <stdint.h>
|
||||
#include <syslog.h>
|
||||
#include <stdbool.h>
|
||||
@ -74,16 +75,15 @@
|
||||
#define DATA_SIZE 4096
|
||||
#define SHA1_HASH_LEN 20
|
||||
|
||||
#define EXT2_IOC_GETVERSION _IOR('v', 1, long)
|
||||
#define EXT34_IOC_GETVERSION _IOR('f', 3, long)
|
||||
|
||||
#define FS_IOC_GETFLAGS _IOR('f', 1, long)
|
||||
#define FS_IOC_SETFLAGS _IOW('f', 2, long)
|
||||
#define FS_IOC32_GETFLAGS _IOR('f', 1, int)
|
||||
#define FS_IOC32_SETFLAGS _IOW('f', 2, int)
|
||||
|
||||
#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;
|
||||
@ -170,8 +170,10 @@ typedef int (*verify_hash_fn_t)(const unsigned char *hash, int size, unsigned ch
|
||||
|
||||
struct libevm_params {
|
||||
int verbose;
|
||||
int x509;
|
||||
const char *hash_algo;
|
||||
char *keyfile;
|
||||
char *keypass;
|
||||
};
|
||||
|
||||
struct RSA_ASN1_template {
|
||||
@ -189,6 +191,11 @@ 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, 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);
|
||||
|
||||
|
306
src/libimaevm.c
306
src/libimaevm.c
@ -44,6 +44,7 @@
|
||||
#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>
|
||||
@ -125,6 +126,7 @@ const struct RSA_ASN1_template RSA_ASN1_templates[PKEY_HASH__LAST] = {
|
||||
|
||||
struct libevm_params params = {
|
||||
.verbose = LOG_INFO - 1,
|
||||
.x509 = 1,
|
||||
.hash_algo = "sha1",
|
||||
};
|
||||
|
||||
@ -152,54 +154,54 @@ int get_filesize(const char *filename)
|
||||
return (int)stats.st_size;
|
||||
}
|
||||
|
||||
static inline int get_fdsize(int fd)
|
||||
static inline off_t get_fdsize(int fd)
|
||||
{
|
||||
struct stat stats;
|
||||
/* Need to know the file length */
|
||||
fstat(fd, &stats);
|
||||
return (int)stats.st_size;
|
||||
return stats.st_size;
|
||||
}
|
||||
|
||||
static int add_file_hash(const char *file, EVP_MD_CTX *ctx)
|
||||
{
|
||||
uint8_t *data;
|
||||
int err, size, bs = DATA_SIZE;
|
||||
size_t len;
|
||||
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");
|
||||
return -1;
|
||||
}
|
||||
|
||||
fp = fopen(file, "r");
|
||||
if (!fp) {
|
||||
log_err("Unable to open %s\n", file);
|
||||
return -1;
|
||||
goto out;
|
||||
}
|
||||
|
||||
for (size = get_fdsize(fileno(fp)); size; size -= len) {
|
||||
len = MIN(size, bs);
|
||||
err = fread(data, len, 1, fp);
|
||||
if (!err) {
|
||||
if (!fread(data, len, 1, fp)) {
|
||||
if (ferror(fp)) {
|
||||
log_err("fread() error\n\n");
|
||||
return -1;
|
||||
log_err("fread() failed\n\n");
|
||||
goto out;
|
||||
}
|
||||
break;
|
||||
}
|
||||
err = EVP_DigestUpdate(ctx, data, len);
|
||||
if (!err) {
|
||||
if (!EVP_DigestUpdate(ctx, data, len)) {
|
||||
log_err("EVP_DigestUpdate() failed\n");
|
||||
return 1;
|
||||
err = 1;
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
|
||||
err = 0;
|
||||
out:
|
||||
fclose(fp);
|
||||
free(data);
|
||||
|
||||
return 0;
|
||||
return err;
|
||||
}
|
||||
|
||||
static int add_dir_hash(const char *file, EVP_MD_CTX *ctx)
|
||||
@ -212,7 +214,7 @@ static int add_dir_hash(const char *file, EVP_MD_CTX *ctx)
|
||||
|
||||
dir = opendir(file);
|
||||
if (!dir) {
|
||||
log_err("Unable to open %s\n", file);
|
||||
log_err("Failed to open: %s\n", file);
|
||||
return -1;
|
||||
}
|
||||
|
||||
@ -255,22 +257,23 @@ 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;
|
||||
const EVP_MD *md;
|
||||
unsigned int mdlen;
|
||||
int err;
|
||||
|
||||
/* Need to know the file length */
|
||||
err = lstat(file, &st);
|
||||
if (err < 0) {
|
||||
log_err("stat() failed\n");
|
||||
log_err("Failed to stat: %s\n", file);
|
||||
return err;
|
||||
}
|
||||
|
||||
@ -326,7 +329,7 @@ RSA *read_pub_key(const char *keyfile, int x509)
|
||||
|
||||
fp = fopen(keyfile, "r");
|
||||
if (!fp) {
|
||||
log_err("Unable to open keyfile %s\n", keyfile);
|
||||
log_err("Failed to open keyfile: %s\n", keyfile);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
@ -533,3 +536,258 @@ int ima_verify_signature(const char *file, unsigned char *sig, int siglen)
|
||||
|
||||
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: %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, char *keypass)
|
||||
{
|
||||
FILE *fp;
|
||||
RSA *key;
|
||||
|
||||
fp = fopen(keyfile, "r");
|
||||
if (!fp) {
|
||||
log_err("Failed to open keyfile: %s\n", keyfile);
|
||||
return NULL;
|
||||
}
|
||||
key = PEM_read_RSAPrivateKey(fp, NULL, NULL, keypass);
|
||||
if (!key)
|
||||
log_err("PEM_read_RSAPrivateKey() failed\n");
|
||||
|
||||
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: %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, unsigned char *sig)
|
||||
{
|
||||
return params.x509 ? sign_hash_v2(hashalgo, hash, size, keyfile, sig) :
|
||||
sign_hash_v1(hashalgo, hash, size, keyfile, sig);
|
||||
}
|
||||
|
Reference in New Issue
Block a user