传输加密（TLS）
2.4.1 注意事项
1) 如果在生产环境安装，注意证书的时间问题。可修改CA.pl脚本
2) 关于/etc/pki/tls/misc目录下的CA.pl脚本，要安装
yum install openssl-perl openssl-devel
3) 客户端工具即使没有CA颁发的证书，也能够通过636端口进行加密传输。前提是OpenLDAP服务器有自己的证书（公钥）、私钥。
4) CA只是签证的“机构”。
5) 要实现传输加密，不是必须要为客户端发送CA的证书文件。
在/etc/ldap.conf的配置文件中
# OpenLDAP SSL options
# Require and verify server certificate (yes/no)
# Default is to use libldap's default behavior, which can be configured in
# /etc/openldap/ldap.conf using the TLS_REQCERT setting. The default for
# OpenLDAP 2.0 and earlier is "no", for 2.1 and later is "yes".
tls_checkpeer yes
此文件中tls_checkpeer默认是yes，当设置为no的时候，就可以不必为客户端发送CA的证书文件。
6) 在/etc/ldap.conf配置文件中，ssl on要与ldaps相对应，开启ssl on就会使用ldaps，并且ssl start_tl sssl on这两个语句一定要保持这个顺序。上下颠倒的话，会提示“重复启用TLS”的错误。
7) /etc/openldap/ldap.conf这个配置文件是工具的配置文件，debug调试
ldapsearch -H ldaps://192.168.60.136 -d225
8) TLSVerifyClient、TLS_REQCERT、tls_checkpeer这三个变量分别对应/etc/openldap/slapd.conf、/etc/openldap/ldap.conf、/etc/ldap.conf三个配置文件。
9) 如果指定的域名，就全部用域名，否则全部用IP地址
2.4.2 配置证书过程
分为3个步骤，首先把CA建立起来，然后让此CA签发一个server的证书和一个client的证书。
需要特别注意的是创建证书时，输入Common Name的时候如果输入FQDN，客户端就指定FQDN连，如果输入IP，客户端就指定IP连
2.4.3 创建CA
这里关系到两个目录，/etc/pki/tls/misc是工作目录,/etc/pki/CA是存放所有CA相关文件的目录。完成此步骤后，会在/etc/pki/CA目录下生成一系列文件，其中最重要的是
/etc/pki/CA/cakey.pem CA的私钥文件
/etc/pki/CA/cacert.pem CA的证书文件
注意：如果脚本检测到/etc/pki/CA下面有文件存在，那么script会安静的退出，不会创建任何东西。把/etc/pki/CA下的文件全部删除，script就可以正常工作了
cd /etc/pki/tls/misc/
rm /etc/pki/CA/ -rf
/etc/pki/tls/misc/CA.pl -newca
CA certificate filename (or enter to create)
rm /etc/pki/CA/ -rf
/etc/pki/tls/misc/CA.pl -newca
CA certificate filename (or enter to create)
Making CA certificate ...
Generating a 1024 bit RSA private key
..................................++++++
.....++++++
writing new private key to '../../CA/private/cakey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:ldapm.dh.cn
Email Address []:
Generating a 1024 bit RSA private key
..................................++++++
.....++++++
writing new private key to '../../CA/private/cakey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:ldapm.dh.cn
Email Address []:
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for ../../CA/private/cakey.pem:
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number:
c4:87:8a:c3:fd:11:b2:61
Validity
Not Before: Jul 23 06:43:39 2010 GMT
Not After : Jul 22 06:43:39 2013 GMT
Subject:
countryName = GB
stateOrProvinceName = Berkshire
organizationName = My Company Ltd
commonName = ldapm.dh.cn
X509v3 extensions:
X509v3 Subject Key Identifier:
4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
X509v3 Authority Key Identifier:
keyid:4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
DirName:/C=GB/ST=Berkshire/O=My Company Ltd/CN=ldapm.dh.cn
serial:C4:87:8A:C3:FD:11:B2:61
to be sent with your certificate request
A challenge password []:
An optional company name []:
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for ../../CA/private/cakey.pem:
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number:
c4:87:8a:c3:fd:11:b2:61
Validity
Not Before: Jul 23 06:43:39 2010 GMT
Not After : Jul 22 06:43:39 2013 GMT
Subject:
countryName = GB
stateOrProvinceName = Berkshire
organizationName = My Company Ltd
commonName = ldapm.dh.cn
X509v3 extensions:
X509v3 Subject Key Identifier:
4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
X509v3 Authority Key Identifier:
keyid:4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
DirName:/C=GB/ST=Berkshire/O=My Company Ltd/CN=ldapm.dh.cn
serial:C4:87:8A:C3:FD:11:B2:61
X509v3 Basic Constraints:
CA:TRUE
Certificate is to be certified until Jul 22 06:43:39 2013 GMT (1095 days)
CA:TRUE
Certificate is to be certified until Jul 22 06:43:39 2013 GMT (1095 days)
Write out database with 1 new entries
Data Base Updated
2.4.4 创建server证书
/etc/pki/tls/misc/CA.pl -newreq-nodes
-nodes参数的作用是，避免每次重启OpenLDAP服务器都要输入密码。
Generating a 1024 bit RSA private key
...............++++++
.++++++
writing new private key to 'newkey.pem'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:ldapm.dh.cn
Email Address []:
Data Base Updated
2.4.4 创建server证书
/etc/pki/tls/misc/CA.pl -newreq-nodes
-nodes参数的作用是，避免每次重启OpenLDAP服务器都要输入密码。
Generating a 1024 bit RSA private key
...............++++++
.++++++
writing new private key to 'newkey.pem'
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [GB]:
State or Province Name (full name) [Berkshire]:
Locality Name (eg, city) [Newbury]:
Organization Name (eg, company) [My Company Ltd]:
Organizational Unit Name (eg, section) []:
Common Name (eg, your name or your server's hostname) []:ldapm.dh.cn
Email Address []:
Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:
An optional company name []:
Request is in newreq.pem, private key is in newkey.pem
2.4.5 签证
/etc/pki/tls/misc/CA.pl -sign
对证书进行签证
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for ../../CA/private/cakey.pem:
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number:
c4:87:8a:c3:fd:11:b2:62
Validity
Not Before: Jul 23 06:52:31 2010 GMT
Not After : Jul 23 06:52:31 2011 GMT
Subject:
countryName = GB
stateOrProvinceName = Berkshire
localityName = Newbury
organizationName = My Company Ltd
commonName = ldapm.dh.cn
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
Netscape Comment:
OpenSSL Generated Certificate
X509v3 Subject Key Identifier:
BE:21:BD:4C:39:C1:B4:26:B4:EB:ED:B6:42:36:97:1F:97:49:15:49
X509v3 Authority Key Identifier:
keyid:4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
to be sent with your certificate request
A challenge password []:
An optional company name []:
Request is in newreq.pem, private key is in newkey.pem
2.4.5 签证
/etc/pki/tls/misc/CA.pl -sign
对证书进行签证
Using configuration from /etc/pki/tls/openssl.cnf
Enter pass phrase for ../../CA/private/cakey.pem:
Check that the request matches the signature
Signature ok
Certificate Details:
Serial Number:
c4:87:8a:c3:fd:11:b2:62
Validity
Not Before: Jul 23 06:52:31 2010 GMT
Not After : Jul 23 06:52:31 2011 GMT
Subject:
countryName = GB
stateOrProvinceName = Berkshire
localityName = Newbury
organizationName = My Company Ltd
commonName = ldapm.dh.cn
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
Netscape Comment:
OpenSSL Generated Certificate
X509v3 Subject Key Identifier:
BE:21:BD:4C:39:C1:B4:26:B4:EB:ED:B6:42:36:97:1F:97:49:15:49
X509v3 Authority Key Identifier:
keyid:4B:11:F1:EE:53:DC:74:2A:66:F4:C5:E4:5A:15:61:8B:7A:4D:1F:2D
Certificate is to be certified until Jul 23 06:52:31 2011 GMT (365 days)
Sign the certificate? [y/n]:y
Sign the certificate? [y/n]:y
1 out of 1 certificate requests certified, commit? [y/n]y
Write out database with 1 new entries
Data Base Updated
Signed certificate is in newcert.pem
运行完两个步骤后，会发现当前目录下创建了3个文件:
newreq.pem 创建证书请求文件，没什么用了
newcert.pem CA签发的证书
newkey.pem 证书对应的私钥
转移文件
mv new* /etc/openldap/cacerts/
cp /etc/pki/CA/cacert.pem /etc/openldap/cacerts/
属主
cd /etc/openldap/cacerts/
chown ldap.ldap *
设置合适的权限
chmod 644 newcert.pem
chmod 600 newkey.pem
把这两个文件和CA的证书文件复制到/etc/openldap/cacerts目录下。
将CA的证书文件（cacert.pem）放到客户端的/etc/openldap/cacerts目录下。
2.4.6 创建客户端证书（暂时未做）
创建client的证书和上面创建server的证书类似。不过要注意的是
1）在输入Common Name的时候输入clien的fully qualified name，或者IP地址。
2）证书文件和私钥文件可以命名为client.cert, client.key，它们和cacert.pem也拷贝到client端的/etc/openldap/cacerts
加在客户端的/etc/ldap.conf文件中
tls_cert /etc/openldap/cacerts/newcert.pem
tls_key /etc/openldap/cacerts/newkey.pem
2.4.7 配置文件
服务器端
1•/etc/openldap/slapd.conf（主配置文件）
TLSCipherSuite HIGH:MEDIUM:+SSLv2:+TLSv1:+SSLv3
TLSCACertificateFile /etc/openldap/cacerts/cacert.pem
TLSCertificateFile /etc/openldap/cacerts/newcert.pem
TLSCertificateKeyFile /etc/openldap/cacerts/newkey.pem
TLSVerifyClient allow
# TLSVerifyClient never/allow/try/demand这几个值，是针对客户端的证书文件认证等级。如果设置为demand，则客户端必须要有自己的经过CA签证的证书文件。
2•/etc/openldap/ldap.conf（ldapsearch等工具的配置文件）
BASE dc=dh,dc=cn
URI ldaps://192.168.60.136/
客户端
3•/etc/ldap.conf
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
uri ldaps://192.168.60.136/
pam_password md5
注意：
ldaps://192.168.60.136/
后面的IP地址，要对应创建证书时候的IP，如果创建证书的时候用域名，在这里也要用域名。
注释：
TLSVerifyClient never
设置是否验证client的身份，其值可以是never/allow/try/demand，配置什么值取决于安全策略。仅仅就配置来说，如果不需要认证client端的身份，那么client只需要有CA的证书就可以了，如果需要认证client端的身份，那么client还必须要有它自己的证书。
/etc/openldap/ldap.conf中的配置文件
测试用的配置文件（可在其他地方成功登录）：
[root@mailsrv cacerts]# cat /etc/ldap.conf |grep -v '^#'|sed /^$/d
newreq.pem 创建证书请求文件，没什么用了
newcert.pem CA签发的证书
newkey.pem 证书对应的私钥
转移文件
mv new* /etc/openldap/cacerts/
cp /etc/pki/CA/cacert.pem /etc/openldap/cacerts/
属主
cd /etc/openldap/cacerts/
chown ldap.ldap *
设置合适的权限
chmod 644 newcert.pem
chmod 600 newkey.pem
把这两个文件和CA的证书文件复制到/etc/openldap/cacerts目录下。
将CA的证书文件（cacert.pem）放到客户端的/etc/openldap/cacerts目录下。
2.4.6 创建客户端证书（暂时未做）
创建client的证书和上面创建server的证书类似。不过要注意的是
1）在输入Common Name的时候输入clien的fully qualified name，或者IP地址。
2）证书文件和私钥文件可以命名为client.cert, client.key，它们和cacert.pem也拷贝到client端的/etc/openldap/cacerts
加在客户端的/etc/ldap.conf文件中
tls_cert /etc/openldap/cacerts/newcert.pem
tls_key /etc/openldap/cacerts/newkey.pem
2.4.7 配置文件
服务器端
1•/etc/openldap/slapd.conf（主配置文件）
TLSCipherSuite HIGH:MEDIUM:+SSLv2:+TLSv1:+SSLv3
TLSCACertificateFile /etc/openldap/cacerts/cacert.pem
TLSCertificateFile /etc/openldap/cacerts/newcert.pem
TLSCertificateKeyFile /etc/openldap/cacerts/newkey.pem
TLSVerifyClient allow
# TLSVerifyClient never/allow/try/demand这几个值，是针对客户端的证书文件认证等级。如果设置为demand，则客户端必须要有自己的经过CA签证的证书文件。
2•/etc/openldap/ldap.conf（ldapsearch等工具的配置文件）
BASE dc=dh,dc=cn
URI ldaps://192.168.60.136/
客户端
3•/etc/ldap.conf
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
uri ldaps://192.168.60.136/
pam_password md5
注意：
ldaps://192.168.60.136/
后面的IP地址，要对应创建证书时候的IP，如果创建证书的时候用域名，在这里也要用域名。
注释：
TLSVerifyClient never
设置是否验证client的身份，其值可以是never/allow/try/demand，配置什么值取决于安全策略。仅仅就配置来说，如果不需要认证client端的身份，那么client只需要有CA的证书就可以了，如果需要认证client端的身份，那么client还必须要有它自己的证书。
/etc/openldap/ldap.conf中的配置文件
测试用的配置文件（可在其他地方成功登录）：
[root@mailsrv cacerts]# cat /etc/ldap.conf |grep -v '^#'|sed /^$/d
base dc=dh,dc=cn
timelimit 120
bind_timelimit 120
idle_timelimit 3600
nss_initgroups_ignoreusers root,ldap,named,avahi,haldaemon,dbus,radvd,tomcat,radiusd,news,mailman
tls_checkpeer yes
tls_ciphers TLSv1
tls_cert /etc/openldap/cacerts/newcert.pem
tls_key /etc/openldap/cacerts/newkey.pem
uri ldaps://192.168.60.136/
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
tls_cacertdir /etc/openldap/cacerts
pam_password md5
timelimit 120
bind_timelimit 120
idle_timelimit 3600
nss_initgroups_ignoreusers root,ldap,named,avahi,haldaemon,dbus,radvd,tomcat,radiusd,news,mailman
tls_checkpeer yes
tls_ciphers TLSv1
tls_cert /etc/openldap/cacerts/newcert.pem
tls_key /etc/openldap/cacerts/newkey.pem
uri ldaps://192.168.60.136/
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
tls_cacertdir /etc/openldap/cacerts
pam_password md5
[root@mailsrv cacerts]# cat /etc/openldap/ldap.conf |grep -v '^#'|sed /^$/d
URI
ldaps://192.168.60.136/
BASE dc=dh,dc=cn
TLS_CACERTDIR /etc/openldap/cacerts
2.4.8 举例（S/C配置文件）
服务器配置文件1：
cat /etc/openldap/slapd.conf |grep -v '^#'|sed /^$/d
BASE dc=dh,dc=cn
TLS_CACERTDIR /etc/openldap/cacerts
2.4.8 举例（S/C配置文件）
服务器配置文件1：
cat /etc/openldap/slapd.conf |grep -v '^#'|sed /^$/d
include /etc/openldap/schema/core.schema
include /etc/openldap/schema/cosine.schema
include /etc/openldap/schema/inetorgperson.schema
include /etc/openldap/schema/nis.schema
include /etc/openldap/schema/misc.schema
include /etc/openldap/schema/openldap.schema
allow bind_v2
pidfile /var/run/openldap/slapd.pid
argsfile /var/run/openldap/slapd.args
access to attrs=shadowLastChange,userPassword by self write by * auth
access to * by * read
TLSCipherSuite HIGH:MEDIUM:+SSLv2
TLSCACertificateFile /etc/openldap/cacerts/cacert.pem
TLSCertificateFile /etc/openldap/cacerts/newcert.pem
TLSCertificateKeyFile /etc/openldap/cacerts/newkey.pem
TLSVerifyClient allow
loglevel -1
database bdb
suffix "dc=dh,dc=cn"
rootdn "cn=ning,dc=dh,dc=cn"
rootpw {MD5}4QrcOUm6Wau+VuBX8g+IPg==
directory /var/lib/ldap
index objectClass eq,pres
index ou,cn,mail,surname,givenname eq,pres,sub
index uidNumber,gidNumber,loginShell eq,pres
index uid,memberUid eq,pres,sub
index nisMapName,nisMapEntry eq,pres,sub
replogfile /var/lib/ldap/replog
replica host=192.168.60.132:389
suffix="dc=dh,dc=cn"
binddn="cn=ning,dc=dh,dc=cn"
credentials=654321
bindmethod=simple
tls=no
服务器配置文件2：
cat /etc/openldap/ldap.conf |grep -v '^#'|sed /^$/d
include /etc/openldap/schema/cosine.schema
include /etc/openldap/schema/inetorgperson.schema
include /etc/openldap/schema/nis.schema
include /etc/openldap/schema/misc.schema
include /etc/openldap/schema/openldap.schema
allow bind_v2
pidfile /var/run/openldap/slapd.pid
argsfile /var/run/openldap/slapd.args
access to attrs=shadowLastChange,userPassword by self write by * auth
access to * by * read
TLSCipherSuite HIGH:MEDIUM:+SSLv2
TLSCACertificateFile /etc/openldap/cacerts/cacert.pem
TLSCertificateFile /etc/openldap/cacerts/newcert.pem
TLSCertificateKeyFile /etc/openldap/cacerts/newkey.pem
TLSVerifyClient allow
loglevel -1
database bdb
suffix "dc=dh,dc=cn"
rootdn "cn=ning,dc=dh,dc=cn"
rootpw {MD5}4QrcOUm6Wau+VuBX8g+IPg==
directory /var/lib/ldap
index objectClass eq,pres
index ou,cn,mail,surname,givenname eq,pres,sub
index uidNumber,gidNumber,loginShell eq,pres
index uid,memberUid eq,pres,sub
index nisMapName,nisMapEntry eq,pres,sub
replogfile /var/lib/ldap/replog
replica host=192.168.60.132:389
suffix="dc=dh,dc=cn"
binddn="cn=ning,dc=dh,dc=cn"
credentials=654321
bindmethod=simple
tls=no
服务器配置文件2：
cat /etc/openldap/ldap.conf |grep -v '^#'|sed /^$/d
URI
ldaps://192.168.60.136/
BASE dc=dh,dc=cn
TLS_CACERTDIR /etc/openldap/cacerts
客户端配置文件（客户端连LDAP服务器，只需要配好/etc/ldap.conf这个文件）
注意：ssl start_tl sssl on这两个语句一定要保持这个顺序。上下颠倒的话，会提示“重复启用TLS”的错误
cat /etc/ldap.conf |grep -v '^#'|sed /^$/d
BASE dc=dh,dc=cn
TLS_CACERTDIR /etc/openldap/cacerts
客户端配置文件（客户端连LDAP服务器，只需要配好/etc/ldap.conf这个文件）
注意：ssl start_tl sssl on这两个语句一定要保持这个顺序。上下颠倒的话，会提示“重复启用TLS”的错误
cat /etc/ldap.conf |grep -v '^#'|sed /^$/d
base dc=dh,dc=cn
timelimit 120
bind_timelimit 120
idle_timelimit 3600
nss_initgroups_ignoreusers root,ldap,named,avahi,haldaemon,dbus,radvd,tomcat,radiusd,news,mailman
uri ldaps://192.168.60.136/
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
pam_password md5
tls_cacertdir /etc/openldap/cacerts
timelimit 120
bind_timelimit 120
idle_timelimit 3600
nss_initgroups_ignoreusers root,ldap,named,avahi,haldaemon,dbus,radvd,tomcat,radiusd,news,mailman
uri ldaps://192.168.60.136/
ssl start_tls
ssl on
tls_cacertfile /etc/openldap/cacerts/cacert.pem
pam_password md5
tls_cacertdir /etc/openldap/cacerts
2.4.9 测试/验证
2.4.9.1 证书测试
openssl s_client -connect 192.168.60.136:636 -showcerts -state -CAfile /etc/openldap/cacerts/cacert.pem
2.4.9.1 证书测试
openssl s_client -connect 192.168.60.136:636 -showcerts -state -CAfile /etc/openldap/cacerts/cacert.pem
2.4.9.2 tcpdump
tcpdump [-nn] [-i 接口] [-w 储存档名] [-c 次数] [-Ae] [-qX] [-r 文件] [所捕获的数据内容]
参数：
-nn，直接以IP及port number显示，而非主机名与服务器名
-i，后面接要监听的网络接口，如eth0
-w，把监听所得的数据包数据储存下来
-c，监听的数据包数量
-A，数据包的内容以ASCII显示，通常用来捕捉WWW的网页数据
-e，使用资料连接层（OSI第二层）的MAC数据包数据来显示
-q，仅列出较为简短的数据包信息，每一行的内容比较精简
-X，可以列出十六进制（hex）以及ASCII的数据包内容，用于监听数据包
-r，从后面的文件将数据包读出来，这个文件是-w生成的
注意，所捕获的数据包信息，通常加入条件进行简化
‘host foo’
‘host 127.0.0.1’
‘net 192.168’
‘src host 127.0.0.1’
‘dst net 192.168’
‘tcp port 21’
还可以利用and与or进行数据包的整合显示
例如：tcpdump –i eth0 –nn port 21
再例如，测试数据包的流向
• 先在一个终端窗口出入’tcpdump –i lo -nn’的监听
• 再打开一个终端对本机登陆’ssh localhost’
查看输出结果
在router上面监听FTP明文的传输数据
tcpdump –I lo –nn –X ‘port 21’
为了让网络接口可以让tcpdump监听，所以执行tcpdump时，网络接口会启动在“混在模式（promiscuous）”
问题：如何使用tcpdump监听来自eth0适配卡且通信协议为port 22，目标来源为192.168.1.100的数据包
tcpdump –i eth0 –nn ‘port 22 and src host 192.168.1.100’
tcpdump [-nn] [-i 接口] [-w 储存档名] [-c 次数] [-Ae] [-qX] [-r 文件] [所捕获的数据内容]
参数：
-nn，直接以IP及port number显示，而非主机名与服务器名
-i，后面接要监听的网络接口，如eth0
-w，把监听所得的数据包数据储存下来
-c，监听的数据包数量
-A，数据包的内容以ASCII显示，通常用来捕捉WWW的网页数据
-e，使用资料连接层（OSI第二层）的MAC数据包数据来显示
-q，仅列出较为简短的数据包信息，每一行的内容比较精简
-X，可以列出十六进制（hex）以及ASCII的数据包内容，用于监听数据包
-r，从后面的文件将数据包读出来，这个文件是-w生成的
注意，所捕获的数据包信息，通常加入条件进行简化
‘host foo’
‘host 127.0.0.1’
‘net 192.168’
‘src host 127.0.0.1’
‘dst net 192.168’
‘tcp port 21’
还可以利用and与or进行数据包的整合显示
例如：tcpdump –i eth0 –nn port 21
再例如，测试数据包的流向
• 先在一个终端窗口出入’tcpdump –i lo -nn’的监听
• 再打开一个终端对本机登陆’ssh localhost’
查看输出结果
在router上面监听FTP明文的传输数据
tcpdump –I lo –nn –X ‘port 21’
为了让网络接口可以让tcpdump监听，所以执行tcpdump时，网络接口会启动在“混在模式（promiscuous）”
问题：如何使用tcpdump监听来自eth0适配卡且通信协议为port 22，目标来源为192.168.1.100的数据包
tcpdump –i eth0 –nn ‘port 22 and src host 192.168.1.100’
2.4.9.3 加密验证
在192.168.60.136上，LDAP服务器上，先不用TLS加密，让数据走389端口
[root@mysql01 ~]# tcpdump -i eth0 -nn -X 'port 389 and src host 192.168.60.136'
在192.168.60.136上，LDAP服务器上，先不用TLS加密，让数据走389端口
[root@mysql01 ~]# tcpdump -i eth0 -nn -X 'port 389 and src host 192.168.60.136'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
17:09:22.214849 IP 192.168.60.136.389 > 192.168.60.132.58077: S 3493217345:3493217345(0) ack 4120875423 win 5792
0x0000: 4500 003c 0000 4000 4006 405f c0a8 3c88 E..<..@.@.@_..<.
0x0010: c0a8 3c84 0185 e2dd d036 4441 f59f 919f ..<......6DA....
0x0020: a012 16a0 51a7 0000 0204 05b4 0402 080a ....Q...........
0x0030: 2071 a9d3 0a3f 90b0 0103 0304 .q...?......
17:09:22.215042 IP 192.168.60.136.389 > 192.168.60.132.58077: . ack 15 win 362
0x0000: 4500 0034 ed91 4000 4006 52d5 c0a8 3c88 E..4..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4442 f59f 91ad ..<......6DB....
0x0020: 8010 016a 9597 0000 0101 080a 2071 a9d3 ...j.........q..
0x0030: 0a3f 90b1 .?..
17:09:22.216399 IP 192.168.60.136.389 > 192.168.60.132.58077: P 1:15(14) ack 15 win 362
0x0000: 4500 0042 ed92 4000 4006 52c6 c0a8 3c88 E..B..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4442 f59f 91ad ..<......6DB....
0x0020: 8018 016a fa91 0000 0101 080a 2071 a9d4 ...j.........q..
0x0030: 0a3f 90b1 300c 0201 0161 070a 0100 0400 .?..0....a......
0x0040: 0400 ..
17:09:22.217659 IP 192.168.60.136.389 > 192.168.60.132.58077: P 15:258(243) ack 205 win 429
0x0000: 4500 0127 ed93 4000 4006 51e0 c0a8 3c88 E..'..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4450 f59f 926b ..<......6DP...k
0x0020: 8018 01ad fb76 0000 0101 080a 2071 a9d6 .....v.......q..
0x0030: 0a3f 90b3 3081 f002 0102 6481 ea04 2075 .?..0.....d....u
0x0040: 6964 3d74 6573 7430 382c 6f75 3d50 656f id=test08,ou=Peo
0x0050: 706c pl
……
从内容输出可以看到id=test08,ou=Peopl这些信息，如果使用TLS加密，这些信息会加密，不以明文显示。
tcpdump -i eth0 -nn -X 'port 636 and src host 192.168.60.136'
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
17:09:22.214849 IP 192.168.60.136.389 > 192.168.60.132.58077: S 3493217345:3493217345(0) ack 4120875423 win 5792
0x0000: 4500 003c 0000 4000 4006 405f c0a8 3c88 E..<..@.@.@_..<.
0x0010: c0a8 3c84 0185 e2dd d036 4441 f59f 919f ..<......6DA....
0x0020: a012 16a0 51a7 0000 0204 05b4 0402 080a ....Q...........
0x0030: 2071 a9d3 0a3f 90b0 0103 0304 .q...?......
17:09:22.215042 IP 192.168.60.136.389 > 192.168.60.132.58077: . ack 15 win 362
0x0000: 4500 0034 ed91 4000 4006 52d5 c0a8 3c88 E..4..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4442 f59f 91ad ..<......6DB....
0x0020: 8010 016a 9597 0000 0101 080a 2071 a9d3 ...j.........q..
0x0030: 0a3f 90b1 .?..
17:09:22.216399 IP 192.168.60.136.389 > 192.168.60.132.58077: P 1:15(14) ack 15 win 362
0x0000: 4500 0042 ed92 4000 4006 52c6 c0a8 3c88 E..B..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4442 f59f 91ad ..<......6DB....
0x0020: 8018 016a fa91 0000 0101 080a 2071 a9d4 ...j.........q..
0x0030: 0a3f 90b1 300c 0201 0161 070a 0100 0400 .?..0....a......
0x0040: 0400 ..
17:09:22.217659 IP 192.168.60.136.389 > 192.168.60.132.58077: P 15:258(243) ack 205 win 429
0x0000: 4500 0127 ed93 4000 4006 51e0 c0a8 3c88 E..'..@[email protected]...<.
0x0010: c0a8 3c84 0185 e2dd d036 4450 f59f 926b ..<......6DP...k
0x0020: 8018 01ad fb76 0000 0101 080a 2071 a9d6 .....v.......q..
0x0030: 0a3f 90b3 3081 f002 0102 6481 ea04 2075 .?..0.....d....u
0x0040: 6964 3d74 6573 7430 382c 6f75 3d50 656f id=test08,ou=Peo
0x0050: 706c pl
……
从内容输出可以看到id=test08,ou=Peopl这些信息，如果使用TLS加密，这些信息会加密，不以明文显示。
tcpdump -i eth0 -nn -X 'port 636 and src host 192.168.60.136'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
17:50:26.572551 IP 192.168.60.136.636 > 192.168.60.132.42959: S 1791535000:1791535000(0) ack 2424350218 win 5792
0x0000: 4500 003c 0000 4000 4006 405f c0a8 3c88 E..<..@.@.@_..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a798 9080 a60a ..<..|..j.......
0x0020: a012 16a0 a69a 0000 0204 05b4 0402 080a ................
0x0030: 2097 45ae 0a65 2c79 0103 0304 ..E..e,y....
17:50:26.590293 IP 192.168.60.136.636 > 192.168.60.132.42959: . ack 143 win 429
0x0000: 4500 0034 e236 4000 4006 5e30 c0a8 3c88 E..4.6@.@.^0..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a799 9080 a698 ..<..|..j.......
0x0020: 8010 01ad e9a2 0000 0101 080a 2097 45c1 ..............E.
0x0030: 0a65 2c8c .e,.
17:50:26.590735 IP 192.168.60.136.636 > 192.168.60.132.42959: . 1:1449(1448) ack 143 win 429
0x0000: 4500 05dc e237 4000 4006 5887 c0a8 3c88 E....7@[email protected]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a799 9080 a698 ..<..|..j.......
0x0020: 8010 01ad 002c 0000 0101 080a 2097 45c1 .....,........E.
0x0030: 0a65 2c8c 1603 0100 4a02 0000 4603 014c .e,.....J...F..L
0x0040: 63c3 e222 131b aea6 e2dd f2f5 f525 3eb6 c..".........%>.
0x0050: 5270 Rp
17:50:26.590792 IP 192.168.60.136.636 > 192.168.60.132.42959: P 1449:1736(287) ack 143 win 429
0x0000: 4500 0153 e238 4000 4006 5d0f c0a8 3c88 E..S.8@.@.]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ad41 9080 a698 ..<..|..j..A....
0x0020: 8018 01ad fba2 0000 0101 080a 2097 45c2 ..............E.
0x0030: 0a65 2c8c 48a5 92de e694 da5f 4112 2a40 .e,.H......_A.*@
0x0040: 7acf 11d7 bc85 839a 8062 89a7 401a a4b5 z........b..@...
0x0050: 1b83 ..
17:50:26.592304 IP 192.168.60.136.636 > 192.168.60.132.42959: . ack 1926 win 791
0x0000: 4500 0034 e239 4000 4006 5e2d c0a8 3c88 E..4.9@.@.^-..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ae60 9080 ad8f ..<..|..j..`....
0x0020: 8010 0317 da74 0000 0101 080a 2097 45c3 .....t........E.
0x0030: 0a65 2c90 .e,.
17:50:26.595519 IP 192.168.60.136.636 > 192.168.60.132.42959: P 1736:1795(59) ack 1926 win 791
0x0000: 4500 006f e23a 4000 4006 5df1 c0a8 3c88 E..o.:@.@.]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ae60 9080 ad8f ..<..|..j..`....
0x0020: 8018 0317 fabe 0000 0101 080a 2097 45c6 ..............E.
0x0030: 0a65 2c90 1403 0100 0101 1603 0100 30ae .e,...........0.
0x0040: bc9e dd29 8a78 843b b624 62e8 6094 efb9 ...).x.;.$b.`...
0x0050: ed45 .E
……
2.4.9.4 关于客户端工具登录问题
比如Softerra LDAP Administrator 2010.2 (64-bit)、及其他Web客户端，都可以没有CA签发的证书，也可以实现加密传输，功能依赖于服务器自己的证书和私钥。
newcert.pem newkey.pem
具体情况查看CA机构和证书相关内容
2.4.10 证书的导入
1) 将CA的证书文件保存为后缀为.cer的文件名，例如cacert.cer
2) 双击cacert.cer
3) 安装证书：选择“受信任的根证书颁发机构”
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
17:50:26.572551 IP 192.168.60.136.636 > 192.168.60.132.42959: S 1791535000:1791535000(0) ack 2424350218 win 5792
0x0000: 4500 003c 0000 4000 4006 405f c0a8 3c88 E..<..@.@.@_..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a798 9080 a60a ..<..|..j.......
0x0020: a012 16a0 a69a 0000 0204 05b4 0402 080a ................
0x0030: 2097 45ae 0a65 2c79 0103 0304 ..E..e,y....
17:50:26.590293 IP 192.168.60.136.636 > 192.168.60.132.42959: . ack 143 win 429
0x0000: 4500 0034 e236 4000 4006 5e30 c0a8 3c88 E..4.6@.@.^0..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a799 9080 a698 ..<..|..j.......
0x0020: 8010 01ad e9a2 0000 0101 080a 2097 45c1 ..............E.
0x0030: 0a65 2c8c .e,.
17:50:26.590735 IP 192.168.60.136.636 > 192.168.60.132.42959: . 1:1449(1448) ack 143 win 429
0x0000: 4500 05dc e237 4000 4006 5887 c0a8 3c88 E....7@[email protected]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 a799 9080 a698 ..<..|..j.......
0x0020: 8010 01ad 002c 0000 0101 080a 2097 45c1 .....,........E.
0x0030: 0a65 2c8c 1603 0100 4a02 0000 4603 014c .e,.....J...F..L
0x0040: 63c3 e222 131b aea6 e2dd f2f5 f525 3eb6 c..".........%>.
0x0050: 5270 Rp
17:50:26.590792 IP 192.168.60.136.636 > 192.168.60.132.42959: P 1449:1736(287) ack 143 win 429
0x0000: 4500 0153 e238 4000 4006 5d0f c0a8 3c88 E..S.8@.@.]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ad41 9080 a698 ..<..|..j..A....
0x0020: 8018 01ad fba2 0000 0101 080a 2097 45c2 ..............E.
0x0030: 0a65 2c8c 48a5 92de e694 da5f 4112 2a40 .e,.H......_A.*@
0x0040: 7acf 11d7 bc85 839a 8062 89a7 401a a4b5 z........b..@...
0x0050: 1b83 ..
17:50:26.592304 IP 192.168.60.136.636 > 192.168.60.132.42959: . ack 1926 win 791
0x0000: 4500 0034 e239 4000 4006 5e2d c0a8 3c88 E..4.9@.@.^-..<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ae60 9080 ad8f ..<..|..j..`....
0x0020: 8010 0317 da74 0000 0101 080a 2097 45c3 .....t........E.
0x0030: 0a65 2c90 .e,.
17:50:26.595519 IP 192.168.60.136.636 > 192.168.60.132.42959: P 1736:1795(59) ack 1926 win 791
0x0000: 4500 006f e23a 4000 4006 5df1 c0a8 3c88 E..o.:@.@.]...<.
0x0010: c0a8 3c84 027c a7cf 6ac8 ae60 9080 ad8f ..<..|..j..`....
0x0020: 8018 0317 fabe 0000 0101 080a 2097 45c6 ..............E.
0x0030: 0a65 2c90 1403 0100 0101 1603 0100 30ae .e,...........0.
0x0040: bc9e dd29 8a78 843b b624 62e8 6094 efb9 ...).x.;.$b.`...
0x0050: ed45 .E
……
2.4.9.4 关于客户端工具登录问题
比如Softerra LDAP Administrator 2010.2 (64-bit)、及其他Web客户端，都可以没有CA签发的证书，也可以实现加密传输，功能依赖于服务器自己的证书和私钥。
newcert.pem newkey.pem
具体情况查看CA机构和证书相关内容
2.4.10 证书的导入
1) 将CA的证书文件保存为后缀为.cer的文件名，例如cacert.cer
2) 双击cacert.cer
3) 安装证书：选择“受信任的根证书颁发机构”
2.4.11 问题
1) CA证书与服务器证书的关系
Server certificate
subject=/C=GB/ST=Berkshire/L=Newbury/O=My Company Ltd/CN=mysql01.dh.cn
issuer=/C=GB/ST=Berkshire/O=My Company Ltd/CN=192.168.60.136
---
Acceptable client certificate CA names
1) CA证书与服务器证书的关系
Server certificate
subject=/C=GB/ST=Berkshire/L=Newbury/O=My Company Ltd/CN=mysql01.dh.cn
issuer=/C=GB/ST=Berkshire/O=My Company Ltd/CN=192.168.60.136
---
Acceptable client certificate CA names
/C=GB/ST=Berkshire/O=My Company Ltd/CN=192.168.60.136
/C=GB/ST=Berkshire/L=Newbury/O=My Company Ltd/CN=mysql01.dh.cn
如果出现红色部分，须将主配置文件下面的变量设置成
allow
TLSVerifyClient allow
2) 系统的版本问题
在CentOS5.2X64上，内核版本是2.6.18-92.el5，它的setup有个问题
[ ] Use MD5 Passwords 总是处于不能选中的状态。
我在CentOS5.5X64和CentOS5.4X32上面都没有这种情况。
这样的现象，使客户机进行LDAP认证时，su - usernanme不能成功，当在CentOS5.5X64和CentOS5.4X32系统上直接su切换用户，就可以成功。
在CentOS5.2X64上，内核版本是2.6.18-92.el5，它的setup有个问题
[ ] Use MD5 Passwords 总是处于不能选中的状态。
我在CentOS5.5X64和CentOS5.4X32上面都没有这种情况。
这样的现象，使客户机进行LDAP认证时，su - usernanme不能成功，当在CentOS5.5X64和CentOS5.4X32系统上直接su切换用户，就可以成功。