Syslog-ng+snoopy日志审计解决方案
Syslog-ng+snoopy
日志审计解决方案
简介：本解决方案通过
syslog-ng+snoopy实现完善的LINUX/UNIX日志集中存储和用户操作行为记录审计功能。Snoopy可以实时捕获用户SHELL下输入的命令并传递给syslog，由于系统默认的syslog功能简单，不支持加密传输，故采用 syslog-ng替换syslog，通过TLS实现日志传输的安全性。
n Syslog-ng软件包
Client
：
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-5-i386/syslog-ng-client-3.1.0-1.rhel5.i386.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-5-amd64/syslog-ng-client-3.1.0-1.rhel5.x86_64.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-4-i386/syslog-ng-client-3.1.0-1.rhel4.i386.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-4-amd64/syslog-ng-client-3.1.0-1.rhel4.x86_64.rpm
Server
：
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-4-amd64/syslog-ng-3.1.0-1.rhel4.x86_64.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-4-i386/syslog-ng-3.1.0-1.rhel4.i386.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-5-i386/syslog-ng-3.1.0-1.rhel5.i386.rpm
http://www.balabit.com/downloads/files/syslog-ng/sources/3.1.0/setups/rhel-5-amd64/syslog-ng-3.1.0-1.rhel5.x86_64.rpm
n Server端安装 syslog-ng server
1. 使用Rpm命令安装对应操作系统的软件包，安装后系统会自动屏蔽syslog服务的启动
2. 配置OPENSSL证书
|
mv /etc/init.d/syslog /etc/init.d/remove.syslog
chmod 750 /opt/syslog-ng
cd /opt/syslog-ng/
mkdir ca.d
cd ca.d
echo '100001' >serial
touch index.txt
mkdir private newcerts
vi openssl.cnf
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Openssl.cnf配置文件如下：
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# OpenSSL example configuration file.
# This is mostly being used for generation of certificate requests.
# This definition stops the following lines choking if HOME isn't
# defined.
HOME
= .
RANDFILE
= $ENV::HOME/.rnd
# Extra OBJECT IDENTIFIER info:
#oid_file
= $ENV::HOME/.oid
oid_section
= new_oids
# To use this configuration file with the "-extfile" option of the
# "openssl x509" utility, name here the section containing the
# X.509v3 extensions to use:
# extensions
=
# (Alternatively, use a configuration file that has only
# X.509v3 extensions in its main [= default] section.)
[ new_oids ]
# We can add new OIDs in here for use by 'ca' and 'req'.
# Add a simple OID like this:
# testoid1=1.2.3.4
# Or use config file substitution like this:
# testoid2=${testoid1}.5.6
####################################################################
[ ca ]
default_ca
= CA_default # The default ca section
####################################################################
[ CA_default ]
dir
= /opt/syslog-ng/ca.d # Where everything is kept
certs
= $dir/certs # Where the issued certs are kept
crl_dir
= $dir/crl # Where the issued crl are kept
database
= /opt/syslog-ng/ca.d/index.txt # database index file.
#unique_subject = no
# Set to 'no' to allow creation of
# several ctificates with same subject.
new_certs_dir
= /opt/syslog-ng/ca.d/newcerts # default place for new certs.
certificate
= $dir/cacert.pem # The CA certificate
serial
= /opt/syslog-ng/ca.d/serial # The current serial number
crlnumber
= $dir/crlnumber # the current crl number
# must be commented out to leave a V1 CRL
crl
= $dir/crl.pem # The current CRL
private_key
= /opt/syslog-ng/ca.d/private/cakey.pem# The private key
RANDFILE
= /opt/syslog-ng/ca.d/private/.rand # private random number file
x509_extensions = usr_cert
# The extentions to add to the cert
# Comment out the following two lines for the "traditional"
# (and highly broken) format.
name_opt
= ca_default # Subject Name options
cert_opt
= ca_default # Certificate field options
# Extension copying option: use with caution.
# copy_extensions = copy
# Extensions to add to a CRL. Note: Netscape communicator chokes on V2 CRLs
# so this is commented out by default to leave a V1 CRL.
# crlnumber must also be commented out to leave a V1 CRL.
# crl_extensions
= crl_ext
default_days
= 365 # how long to certify for
default_crl_days= 30
# how long before next CRL
default_md
= sha1 # which md to use.
preserve
= no # keep passed DN ordering
# A few difference way of specifying how similar the request should look
# For type CA, the listed attributes must be the same, and the optional
# and supplied fields are just that :-)
policy
= policy_match
# For the CA policy
[ policy_match ]
countryName
= match
stateOrProvinceName
= match
organizationName
= match
organizationalUnitName = optional
commonName
= supplied
emailAddress
= optional
# For the 'anything' policy
# At this point in time, you must list all acceptable 'object'
# types.
[ policy_anything ]
stateOrProvinceName
= GD
localityName
= optional
organizationName
= Xxxxxxxx
organizationalUnitName = SP
commonName
= supplied
emailAddress
= [email protected]
countryName
= CN
####################################################################
[ req ]
default_bits
= 1024
default_md
= sha1
default_keyfile
= privkey.pem
distinguished_name
= req_distinguished_name
attributes
= req_attributes
x509_extensions = v3_ca # The extentions to add to the self signed cert
# Passwords for private keys if not present they will be prompted for
# input_password = secret
# output_password = secret
# This sets a mask for permitted string types. There are several options.
# default: PrintableString, T61String, BMPString.
# pkix
: PrintableString, BMPString.
# utf8only: only UTF8Strings.
# nombstr : PrintableString, T61String (no BMPStrings or UTF8Strings).
# MASK:XXXX a literal mask value.
# WARNING: current versions of Netscape crash on BMPStrings or UTF8Strings
# so use this option with caution!
# we use PrintableString+UTF8String mask so if pure ASCII texts are used
# the resulting certificates are compatible with Netscape
string_mask = MASK:0x2002
# req_extensions = v3_req # The extensions to add to a certificate request
[ req_distinguished_name ]
countryName
= Country Name (2 letter code)
countryName_default
= CN
countryName_min
= 2
countryName_max
= 2
stateOrProvinceName
= State or Province Name (full name)
stateOrProvinceName_default
= GD
localityName
= Locality Name (eg, city)
localityName_default
= ShenZhen
0.organizationName
= Organization Name (eg, company)
0.organizationName_default
= Xxxxxxxx
# we can do this but it is not needed normally :-)
#1.organizationName
= Second Organization Name (eg, company)
#1.organizationName_default
= World Wide Web Pty Ltd
organizationalUnitName
= Organizational Unit Name (eg, section)
#organizationalUnitName_default =
commonName
= Common Name (eg, your name or your server\'s hostname)
commonName_max
= 64
emailAddress
= Email Address
emailAddress_max
= 64
# SET-ex3
= SET extension number 3
[ req_attributes ]
challengePassword
= A challenge password
challengePassword_min
= 4
challengePassword_max
= 20
unstructuredName
= An optional company name
[ usr_cert ]
# These extensions are added when 'ca' signs a request.
# This goes against PKIX guidelines but some CAs do it and some software
# requires this to avoid interpreting an end user certificate as a CA.
basicConstraints=CA:FALSE
# Here are some examples of the usage of nsCertType. If it is omitted
# the certificate can be used for anything *except* object signing.
# This is OK for an SSL server.
# nsCertType
= server
# For an object signing certificate this would be used.
# nsCertType = objsign
# For normal client use this is typical
# nsCertType = client, email
# and for everything including object signing:
# nsCertType = client, email, objsign
# This is typical in keyUsage for a client certificate.
# keyUsage = nonRepudiation, digitalSignature, keyEncipherment
# This will be displayed in Netscape's comment listbox.
nsComment
= "OpenSSL Generated Certificate"
# PKIX recommendations harmless if included in all certificates.
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid,issuer
# This stuff is for subjectAltName and issuerAltname.
# Import the email address.
# subjectAltName=email:copy
# An alternative to produce certificates that aren't
# deprecated according to PKIX.
# subjectAltName=email:move
# Copy subject details
# issuerAltName=issuer:copy
#nsCaRevocationUrl
= http://www.domain.dom/ca-crl.pem
#nsBaseUrl
#nsRevocationUrl
#nsRenewalUrl
#nsCaPolicyUrl
#nsSslServerName
[ v3_req ]
# Extensions to add to a certificate request
basicConstraints = CA:FALSE
keyUsage = nonRepudiation, digitalSignature, keyEncipherment
[ v3_ca ]
# Extensions for a typical CA
# PKIX recommendation.
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid:always,issuer:always
# This is what PKIX recommends but some broken software chokes on critical
# extensions.
#basicConstraints = critical,CA:true
# So we do this instead.
basicConstraints = CA:true
# Key usage: this is typical for a CA certificate. However since it will
# prevent it being used as an test self-signed certificate it is best
# left out by default.
# keyUsage = cRLSign, keyCertSign
# Some might want this also
# nsCertType = sslCA, emailCA
# Include email address in subject alt name: another PKIX recommendation
# subjectAltName=email:copy
# Copy issuer details
# issuerAltName=issuer:copy
# DER hex encoding of an extension: beware experts only!
# obj=DER:02:03
# Where 'obj' is a standard or added object
# You can even override a supported extension:
# basicConstraints= critical, DER:30:03:01:01:FF
[ crl_ext ]
# CRL extensions.
# Only issuerAltName and authorityKeyIdentifier make any sense in a CRL.
# issuerAltName=issuer:copy
authorityKeyIdentifier=keyid:always,issuer:always
[ proxy_cert_ext ]
# These extensions should be added when creating a proxy certificate
# This goes against PKIX guidelines but some CAs do it and some software
# requires this to avoid interpreting an end user certificate as a CA.
basicConstraints=CA:FALSE
# Here are some examples of the usage of nsCertType. If it is omitted
# the certificate can be used for anything *except* object signing.
# This is OK for an SSL server.
# nsCertType
= server
# For an object signing certificate this would be used.
# nsCertType = objsign
# For normal client use this is typical
# nsCertType = client, email
# and for everything including object signing:
# nsCertType = client, email, objsign
# This is typical in keyUsage for a client certificate.
# keyUsage = nonRepudiation, digitalSignature, keyEncipherment
# This will be displayed in Netscape's comment listbox.
nsComment
= "OpenSSL Generated Certificate"
# PKIX recommendations harmless if included in all certificates.
subjectKeyIdentifier=hash
authorityKeyIdentifier=keyid,issuer:always
# This stuff is for subjectAltName and issuerAltname.
# Import the email address.
# subjectAltName=email:copy
# An alternative to produce certificates that aren't
# deprecated according to PKIX.
# subjectAltName=email:move
# Copy subject details
# issuerAltName=issuer:copy
#nsCaRevocationUrl
= http://www.domain.dom/ca-crl.pem
#nsBaseUrl
#nsRevocationUrl
#nsRenewalUrl
#nsCaPolicyUrl
#nsSslServerName
# This really needs to be in place for it to be a proxy certificate.
proxyCertInfo=critical,language:id-ppl-anyLanguage,pathlen:3,policy:foo
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接下来创建证书，注意要输入一致的信息，同时
common name
需要输入服务器的
IP
地址或者域名，这个直接关系到验证是否成功（另外需要确保
server
和
client
的时间一致）
· Create a CA with a key and generate a certificate request
· Create a CA with a key and generate a certificate request
openssl req -new -config openssl.cnf -keyout private/cakey.pem -out careq.pem
· Now create a certificate for the CA by using the above key and self sign it.
openssl ca -config openssl.cnf -create_serial -out external-ca.csr -batch -keyfile private/cakey.pem -selfsign -extensions v3_ca -infiles careq.pem
· Now copy external-ca.csr to cacert.pem because the next command will by default look for the CA certificate with the name cacert.pem
cp external-ca.csr cacert.pem
· Now create server keys and generate a server certificate request
openssl req -nodes -new -keyout external-server.key -out cert-req.pem -config openssl.cnf
· Now create a certificate for the server by using the above key and sign it with the CA certificate
openssl ca -config openssl.cnf -out external-server.csr -batch -infiles cert-req.pem
Now we have the following with us
External-ca.csr: CA certificate
External-server.csr: Server certificate which contains the public key
External-server.key: Server private key
n syslog-ng server服务器端配置文件
server和client使用TLS验证，但从简化部署的角度，所有的client共用一个证书文件，另外调整了server上的一些参数，启用了流量控制。
server端通过2个log配置，将收到的客户端发过来的日志保存到对应主机IP目录下的2个日志文件：
1. snoopy是用户SHELL操作命令记录
2. messages是除了snooopy以外的所有日志
注意：需要修改/tmp目录为正式的主日志保存目录，并对这个目录执行chmod 700
vi /opt/syslog-ng/etc/syslog-ng.conf
|
@version: 3.0
options {
flush_lines (0);
time_reopen (1);
log_fifo_size (163840);
long_hostnames(off);
use_dns (no);
use_fqdn (no);
create_dirs (yes);
keep_hostname (no);
stats_freq(43200);
};
source src {
unix-stream("/dev/log");
internal();
file("/proc/kmsg" program_override("kernel: "));
};
source s_net {
tcp( port(6514)
max-connections(300)
log_iw_size(36000)
log_fetch_limit(100)
tls
(
key_file("/opt/syslog-ng/ca.d/external-server.key")
cert_file("/opt/syslog-ng/ca.d/external-server.csr")
peer_verify(optional-untrusted)
)
);
syslog();
};
destination d_boot { file("/var/log/boot.log"); };
destination d_cron { file("/var/log/cron.log"); };
destination d_daemon { file("/var/log/daemon.log"); };
destination d_kernel { file("/var/log/kernel.log"); };
destination d_mail { file("/var/log/maillog"); };
destination d_spooler { file("/var/log/spooler"); };
destination d_messages { file("/var/log/messages"); };
destination d_console { usertty("root"); };
destination d_secure { file("/var/log/secure"); };
destination d_fromremote_messages { file("
/tmp/$SOURCEIP/messages.$R_YEAR-$R_MONTH-$R_DAY" log_fifo_size(360000)); };
destination d_fromremote_snoopy { file("
/tmp/$SOURCEIP/snoopy.$R_YEAR-$R_MONTH-$R_DAY" log_fifo_size(360000)); };
filter f_boot { facility(local7); };
filter f_cron { facility(cron); };
filter f_daemon { facility(daemon); };
filter f_kernel { facility(kern); };
filter f_mail { facility(mail); };
filter f_uucp { facility(cron); };
filter f_news { facility(news); };
filter f_messages { level(info..emerg) and not facility(auth, authpriv, mail, news); };
filter f_emergency { level(emerg); };
filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };
filter f_spooler { level(crit...emerg) and facility(news) or facility(uucp); };
filter f_secure { facility(authpriv,auth) and not program(snoopy); };
filter f_notdebug_notmail { level(info...emerg) and not facility(mail); };
filter f_snoopy { program(snoopy); };
filter f_not_snoopy { not program(snoopy); };
log { source(src); filter(f_boot); destination(d_boot); };
log { source(src); filter(f_cron); destination(d_cron); };
log { source(src); filter(f_daemon); destination(d_daemon); };
log { source(src); filter(f_kernel); destination(d_kernel); };
log { source(src); filter(f_mail); destination(d_mail); };
log { source(src); filter(f_messages); destination(d_messages); };
log { source(src); filter(f_emergency); destination(d_console); };
log { source(src); filter(f_secure); destination(d_secure); };
log { source(src); filter(f_spooler); destination(d_spooler); };
log { source(s_net); filter(f_snoopy); destination(d_fromremote_snoopy); flags(flow_control); };
log { source(s_net); filter(f_not_snoopy); destination(d_fromremote_messages); flags(flow-control); };
|
/etc/init.d/syslog-ng restart
至此，SYSLOG-NG SERVER 配置完成。
n
Client
端安装 snoopy
|
wget http://ncu.dl.sourceforge.net/project/snoopylogger/snoopylogger/snoopy-1.6.1.tar.gz
tar zxvf snoopy-1.6.1.tar.gz
cd snoopy-1.6.1
./configure
make
make install
make enable
cd ..
rm -rf snoopy-1.6.1*
|
n
Client
端安装syslog-ng client
1. 使用Rpm命令安装对应操作系统的软件包，安装后系统会自动屏蔽syslog服务的启动
|
mv /etc/init.d/syslog /etc/init.d/remove.syslog
chmod 750 /opt/syslog-ng
cd /opt/syslog-ng/etc
vi syslog-ng.conf
|
Syslog-ng.conf配置文件如下
|
@version: 3.0
options {
flush_lines (0);
time_reopen (5);
log_fifo_size (16384);
long_hostnames(off);
use_dns (no);
use_fqdn (no);
create_dirs (yes);
keep_hostname (no);
stats_freq(43200);
};
source src {
unix-stream("/dev/log" log_fetch_limit(100) log_iw_size(1000));
internal();
file("/proc/kmsg" program_override("kernel: ") log_fetch_limit(100) log_iw_size(1000));
};
destination d_boot { file("/var/log/boot.log"); };
destination d_cron { file("/var/log/cron.log"); };
destination d_daemon { file("/var/log/daemon.log"); };
destination d_kernel { file("/var/log/kernel.log"); };
destination d_mail { file("/var/log/maillog"); };
destination d_spooler { file("/var/log/spooler"); };
destination d_messages { file("/var/log/messages"); };
destination d_console { usertty("root"); };
destination d_secure { file("/var/log/secure"); };
destination d_remote {
tcp("192.168.168.122" port(6514)
tls( ca_dir("/opt/syslog-ng/etc/")) ); };
filter f_boot { facility(local7); };
filter f_cron { facility(cron); };
filter f_daemon { facility(daemon); };
filter f_kernel { facility(kern); };
filter f_mail { facility(mail); };
filter f_uucp { facility(cron); };
filter f_news { facility(news); };
filter f_messages { level(info..emerg) and not facility(auth, authpriv, mail, news); };
filter f_emergency { level(emerg); };
filter f_info { level(info); };
filter f_notice { level(notice); };
filter f_warn { level(warn); };
filter f_crit { level(crit); };
filter f_err { level(err); };
filter f_spooler { level(crit...emerg) and facility(news) or facility(uucp); };
filter f_secure { facility(authpriv,auth) and not program(snoopy); };
filter f_notdebug_notmail { level(info...emerg) and not facility(mail); };
log { source(src); filter(f_boot); destination(d_boot); };
log { source(src); filter(f_cron); destination(d_cron); };
log { source(src); filter(f_daemon); destination(d_daemon); };
log { source(src); filter(f_kernel); destination(d_kernel); };
log { source(src); filter(f_mail); destination(d_mail); };
log { source(src); filter(f_messages); destination(d_messages); };
log { source(src); filter(f_emergency); destination(d_console); };
log { source(src); filter(f_secure); destination(d_secure); };
log { source(src); filter(f_spooler); destination(d_spooler); };
log { source(src); filter(f_notdebug_notmail); destination(d_remote); flags(flow-control);};
|
将前面在Server上用openssl命令产生的external-ca.csr文件COPY到syslog-ng客户端的/opt/syslog-ng/etc目录下，然后执行下面的命令：
openssl x509 –noout –hash –in external-ca.csr
· The output of the above command is a hash value and will be of the format fa6084d0. Now create a symbolic link for the certificate for debugging purposes.
ln –s external-ca.csr fa6084d0.0
(please note the .0 suffix)
/etc/init.d/syslog-ng restart
至此，SYSLOG-NG client
配置完成。
n
Server Debug
使用下面的命令启动
syslog-ng
，即可在控制台查看详细
DEBUG
信息
/opt/syslog-ng/sbin/syslog-ng -e -F -d -v
n
关于
Flow-control
为了启用流量控制，Flags(flow-control)必须在log对象里面激活，并通过source/destination的几个属性控制。
For example:
log { source(s_localhost); destination(d_tcp); flags(flow-control); };
source:
log_iw_size > max_connections() *log_fetch_limit
log_fetch_limit() (default value: 10)
(每个source上独立连接，对于TCP and unix-stream sources, syslog-ng从每个source的每个连接读取log_fetch_limit() 条消息
log_iw_size() (default value: 100)
Flow-control使用一个control window来决定输出buffer里面是否有空闲空间为新的messages使用.
每个source有自己的control window-- log_iw_size() parameter
当一个source容许多个连接，每个连接的消息使用同一个control window.
如果control window 满了, syslog-ng 停止从source读取消息直到一些消息成功发送给destination.
destination:
log_fifo_size > log_iw_size *10
每个destination有一个输出buffer (log_fifo_size()).The log_fifo_size() parameter sets the size of the output buffer.
输出buffer必须大于每个SOURCE发送给destination的control window
如果output buffer满了，并且disk-buffering 和 flow-control 都没有使用, messages may be lost.
n
Replacing klogd on Linux
The syslog-ng application can replace both the syslogd and klogd daemons on Linux hosts. To replace klogd, complete the following steps:
Add a file source pointing to /proc/kmsg to the syslog-ng configuration file.
source s_kmsg { file("/proc/kmsg"); };
Warning
Do not use a pipe source to read /proc/kmsg; pipe opens the source in read-write mode and this may cause problems when using SELinux or similar security measures.
Include the source defined in Step 1 in a log path.
Stop klogd.
Do not run klogd and syslog-ng simultaneously when using syslog-ng to read /proc/kmsg, as it might block syslog-ng.