go-libaudit is a library for Go (golang) for communicating with the Linux Audit Framework. The Linux Audit Framework provides system call auditing in the kernel and logs the events to user-space using netlink sockets. This library facilitates user-space applications that want to receive audit events.
Package documentation can be found on GoDoc.
Installation can be done with a normal go get:
$ go get github.com/elastic/go-libaudit
go-libaudit has two example applications that you can use to try the library.
The first is audit which registers to receive audit events from the kernel
and outputs the data it receives to stdout. The system's auditd process
should be stopped first.
$ go install github.com/elastic/go-libaudit/cmd/audit@main
$ sudo $GOPATH/bin/audit -d
The second is auparse which parses the log files from the Linux auditd process or the output of the audit example command. It combines related log messages that are a part of the same event.
$ go install github.com/elastic/go-libaudit/cmd/auparse@main
$ sudo cat /var/log/audit/audit.log | auparse
---
type=CRED_ACQ msg=audit(1481077334.302:545): pid=1444 uid=0 auid=1000 ses=4 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:setcred grantors=pam_env,pam_unix acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
---
type=USER_START msg=audit(1481077334.303:546): pid=1444 uid=0 auid=1000 ses=4 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:session_open grantors=pam_keyinit,pam_limits acct="root" exe="/usr/bin/sudo" hostname=? addr=? terminal=/dev/pts/1 res=success'
---
type=SYSCALL msg=audit(1481077334.304:547): arch=c000003e syscall=59 success=yes exit=0 a0=7f683953a5d8 a1=7f683953fd38 a2=7f6839543a90 a3=6 items=2 ppid=1444 pid=1445 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts1 ses=4 comm="su" exe="/usr/bin/su" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)
type=EXECVE msg=audit(1481077334.304:547): argc=1 a0="su"
type=CWD msg=audit(1481077334.304:547): cwd="/home/andrew_kroh"
type=PATH msg=audit(1481077334.304:547): item=0 name="/bin/su" inode=5026 dev=08:01 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:su_exec_t:s0 objtype=NORMAL
type=PATH msg=audit(1481077334.304:547): item=1 name="/lib64/ld-linux-x86-64.so.2" inode=16778495 dev=08:01 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0 objtype=NORMAL
It supports outputting the messages as plain text (default), JSON, or YAML by
using -format=yaml for example.
$ sudo cat /var/log/audit/audit.log | auparse -format=json
---
{"@timestamp":"2016-12-07 02:22:14.302 +0000 UTC","acct":"root","auid":"1000","exe":"/usr/bin/sudo","grantors":"pam_env,pam_unix","op":"PAM:setcred","pid":"1444","raw_msg":"audit(1481077334.302:545): pid=1444 uid=0 auid=1000 ses=4 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:setcred grantors=pam_env,pam_unix acct=\"root\" exe=\"/usr/bin/sudo\" hostname=? addr=? terminal=/dev/pts/1 res=success'","record_type":"CRED_ACQ","result":"success","sequence":"545","ses":"4","subj_category":"c0.c1023","subj_domain":"unconfined_t","subj_level":"s0-s0","subj_role":"unconfined_r","subj_user":"unconfined_u","terminal":"/dev/pts/1","uid":"0"}
---
{"@timestamp":"2016-12-07 02:22:14.303 +0000 UTC","acct":"root","auid":"1000","exe":"/usr/bin/sudo","grantors":"pam_keyinit,pam_limits","op":"PAM:session_open","pid":"1444","raw_msg":"audit(1481077334.303:546): pid=1444 uid=0 auid=1000 ses=4 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='op=PAM:session_open grantors=pam_keyinit,pam_limits acct=\"root\" exe=\"/usr/bin/sudo\" hostname=? addr=? terminal=/dev/pts/1 res=success'","record_type":"USER_START","result":"success","sequence":"546","ses":"4","subj_category":"c0.c1023","subj_domain":"unconfined_t","subj_level":"s0-s0","subj_role":"unconfined_r","subj_user":"unconfined_u","terminal":"/dev/pts/1","uid":"0"}
---
{"@timestamp":"2016-12-07 02:22:14.304 +0000 UTC","a0":"7f683953a5d8","a1":"7f683953fd38","a2":"7f6839543a90","a3":"6","arch":"x86_64","auid":"1000","comm":"su","egid":"0","euid":"0","exe":"/usr/bin/su","exit":"0","fsgid":"0","fsuid":"0","gid":"0","items":"2","pid":"1445","ppid":"1444","raw_msg":"audit(1481077334.304:547): arch=c000003e syscall=59 success=yes exit=0 a0=7f683953a5d8 a1=7f683953fd38 a2=7f6839543a90 a3=6 items=2 ppid=1444 pid=1445 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=pts1 ses=4 comm=\"su\" exe=\"/usr/bin/su\" subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 key=(null)","record_type":"SYSCALL","result":"success","sequence":"547","ses":"4","sgid":"0","subj_category":"c0.c1023","subj_domain":"unconfined_t","subj_level":"s0-s0","subj_role":"unconfined_r","subj_user":"unconfined_u","suid":"0","syscall":"execve","tty":"pts1","uid":"0"}
{"@timestamp":"2016-12-07 02:22:14.304 +0000 UTC","a0":"su","argc":"1","raw_msg":"audit(1481077334.304:547): argc=1 a0=\"su\"","record_type":"EXECVE","sequence":"547"}
{"@timestamp":"2016-12-07 02:22:14.304 +0000 UTC","cwd":"/home/andrew_kroh","raw_msg":"audit(1481077334.304:547): cwd=\"/home/andrew_kroh\"","record_type":"CWD","sequence":"547"}
{"@timestamp":"2016-12-07 02:22:14.304 +0000 UTC","dev":"08:01","inode":"5026","item":"0","mode":"0104755","name":"/bin/su","obj_domain":"su_exec_t","obj_level":"s0","obj_role":"object_r","obj_user":"system_u","objtype":"NORMAL","ogid":"0","ouid":"0","raw_msg":"audit(1481077334.304:547): item=0 name=\"/bin/su\" inode=5026 dev=08:01 mode=0104755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:su_exec_t:s0 objtype=NORMAL","rdev":"00:00","record_type":"PATH","sequence":"547"}
{"@timestamp":"2016-12-07 02:22:14.304 +0000 UTC","dev":"08:01","inode":"16778495","item":"1","mode":"0100755","name":"/lib64/ld-linux-x86-64.so.2","obj_domain":"ld_so_t","obj_level":"s0","obj_role":"object_r","obj_user":"system_u","objtype":"NORMAL","ogid":"0","ouid":"0","raw_msg":"audit(1481077334.304:547): item=1 name=\"/lib64/ld-linux-x86-64.so.2\" inode=16778495 dev=08:01 mode=0100755 ouid=0 ogid=0 rdev=00:00 obj=system_u:object_r:ld_so_t:s0 objtype=NORMAL","rdev":"00:00","record_type":"PATH","sequence":"547"}
To normalize and interpret the messages, use the -i flag for "interpret". This
adds a category to the event and creates the actor, action, thing, and
how fields based on data from the event. By default it will resolve UID and
GID values to their names (use -id=false to disable this).
$ sudo cat /var/log/audit/audit.log | auparse -format=yaml -i
---
timestamp: 2016-12-07T02:22:14.302Z
sequence: 545
category: user-login
record_type: cred_acq
result: success
session: "4"
summary:
actor:
primary: vagrant
secondary: root
action: acquired-credentials
object:
type: user-session
primary: /dev/pts/1
how: /usr/bin/sudo
user:
ids:
auid: "1000"
uid: "0"
names:
auid: vagrant
uid: root
selinux:
category: c0.c1023
domain: unconfined_t
level: s0-s0
role: unconfined_r
user: unconfined_u
process:
pid: "1444"
exe: /usr/bin/sudo
data:
acct: root
grantors: pam_env,pam_unix
op: PAM:setcred
terminal: /dev/pts/1
ecs:
event:
category:
- authentication
type:
- info
user:
name: vagrant
id: "1000"
effective:
name: root
id: "0"
target: {}
changes: {}
group: {}
---
timestamp: 2016-12-07T02:22:14.303Z
sequence: 546
category: user-login
record_type: user_start
result: success
session: "4"
summary:
actor:
primary: vagrant
secondary: root
action: started-session
object:
type: user-session
primary: /dev/pts/1
how: /usr/bin/sudo
user:
ids:
auid: "1000"
uid: "0"
names:
auid: vagrant
uid: root
selinux:
category: c0.c1023
domain: unconfined_t
level: s0-s0
role: unconfined_r
user: unconfined_u
process:
pid: "1444"
exe: /usr/bin/sudo
data:
acct: root
grantors: pam_keyinit,pam_limits
op: PAM:session_open
terminal: /dev/pts/1
ecs:
event:
category:
- authentication
type:
- info
user:
name: vagrant
id: "1000"
effective:
name: root
id: "0"
target: {}
changes: {}
group: {}
---
timestamp: 2016-12-07T02:22:14.304Z
sequence: 547
category: audit-rule
record_type: syscall
result: success
session: "4"
summary:
actor:
primary: vagrant
secondary: root
action: executed
object:
type: file
primary: /bin/su
how: /usr/bin/su
user:
ids:
auid: "1000"
egid: "0"
euid: "0"
fsgid: "0"
fsuid: "0"
gid: "0"
sgid: "0"
suid: "0"
uid: "0"
names:
auid: vagrant
egid: root
euid: root
fsgid: root
fsuid: root
gid: root
sgid: root
suid: root
uid: root
selinux:
category: c0.c1023
domain: unconfined_t
level: s0-s0
role: unconfined_r
user: unconfined_u
process:
pid: "1445"
ppid: "1444"
name: su
exe: /usr/bin/su
cwd: /home/andrew_kroh
args:
- su
file:
path: /bin/su
device: "00:00"
inode: "5026"
mode: "0755"
uid: "0"
gid: "0"
owner: root
group: root
selinux:
domain: su_exec_t
level: s0
role: object_r
user: system_u
data:
a0: 7f683953a5d8
a1: 7f683953fd38
a2: 7f6839543a90
a3: "6"
arch: x86_64
argc: "1"
exit: "0"
syscall: execve
tty: pts1
paths:
- dev: "08:01"
inode: "5026"
item: "0"
mode: "0104755"
name: /bin/su
obj_domain: su_exec_t
obj_level: s0
obj_role: object_r
obj_user: system_u
objtype: NORMAL
ogid: "0"
ouid: "0"
rdev: "00:00"
- dev: "08:01"
inode: "16778495"
item: "1"
mode: "0100755"
name: /lib64/ld-linux-x86-64.so.2
obj_domain: ld_so_t
obj_level: s0
obj_role: object_r
obj_user: system_u
objtype: NORMAL
ogid: "0"
ouid: "0"
rdev: "00:00"
ecs:
event:
category:
- process
type:
- start
user:
effective: {}
target: {}
changes: {}
group: {}
This currently provides Elastic Common Schema (ECS) 1.8 categorization support for some of the more prominent or meaningful auditd events and syscalls.
