Magnus K Karlsson: February 2020

February 27, 2020

X.509 Certificate Profiles

Mandatory Fields

Serial Number
Issuer DN
Validity
Subject DN
Subject Public Key Info	Contains key algorithm, size and info.

Certificate Extensions

Basic Contraints	Critical	If CA or not.
Authority Key Identifier		Hash of CA public key.
Subject Key Identifier		Hash of public key.
Authority Information Access		Contains URL to OCSP and CA certificate.
CRL Distribution Points		URL to CRL.
Certificate Policies		Organization OID for their certificate policy..
Key Usage	Critical	Key usage attribute derived from Extended Key Usage.
Extended Key Usage		Typical values are from RFC 5280.
Subject Alternative Names		Their are different SAN: DNS (for web servers), email (S-MIME) and UPN (Windows login).

RFC 5280

https://tools.ietf.org/html/rfc5280#section-4.2.1.3

Key Usage:

digitalSignature -
nonRepudiation -
keyEncipherment - "subject public key (e.g. RSA) is used for enciphering private or secret keys"
dataEncipherment - "NOTE that the use of this bit is extremely uncommon"
keyAgreement - "subject public key is used for key agreement (Diffie-Hellman key)"
keyCertSign - "If set then CA bit in the basic constraints extension MUST also be set"
cRLSign -

Extended Key Usage:

serverAuth - Key Usage may be: digitalSignature, keyEncipherment or keyAgreement
clientAuth - Key Usage may be: digitalSignature and/or keyAgreement
codeSigning - Key Usage may be: digitalSignature
emailProtection - Key Usage may be: digitalSignature, nonRepudiation, and/or (keyEncipherment or keyAgreement)
timeStamping - Key Usage may be: digitalSignature and/or nonRepudiation
OCSPSigning - Key Usage may be: digitalSignature and/or nonRepudiation

EJBCA CE ROOT CA


Basic Constraints - CRITICAL

CA:TRUE

Path Length Constraint: Unlimited

Authority Key ID

Subject Key ID

Key Usage - CRITICAL:
  digitalSignature
  keyCertSign
  cRLSign
  
Extended Key Usage:
    -

Dogtag caCert


https://github.com/dogtagpki/pki/blob/master/base/ca/shared/conf/caCert.profile

Basic Constraints - CRITICAL

CA:TRUE

Path Length Constraint: Unlimited

Authority Key ID

Subject Key ID

Key Usage - CRITICAL:
  digitalSignature
  nonRepudiation
  keyCertSign
  cRLSign
  
Extended Key Usage:
    -

EJBCA CE SERVER


Basic Constraints - CRITICAL

Authority Key ID

Subject Key ID

Key Usage - CRITICAL:
  digitalSignature
  keyEncipherment
  
Extended Key Usage:
    serverAuth

Dogtag rsaServerCert


https://github.com/dogtagpki/pki/blob/master/base/ca/shared/conf/rsaServerCert.profile

Authority Key ID

Key Usage - CRITICAL:
  digitalSignature
  dataEncipherment
  keyEncipherment

Extended Key Usage:
    serverAuth

EJBCA CE END USER


Basic Constraints - CRITICAL

Authority Key ID

Subject Key ID

Key Usage - Critical:
  digitalSignature
  nonRepudiation
  keyEncipherment
  
Extended Key Usage:
    clientAuth
    emailProtection

Dogtag rsaSubsystemCert


https://github.com/dogtagpki/pki/blob/master/base/ca/shared/conf/rsaSubsystemCert.profile

Authority Key ID

Key Usage - Critical:
  digitalSignature
  nonRepudiation
  dataEncipherment
  keyEncipherment
  
Extended Key Usage:
    clientAuth

EJBCA CE OCSP


Basic Constraints - CRITICAL

Authority Key ID

Subject Key ID

Key Usage - CRITICAL:
  digitalSignature
  
Extended Key Usage:
    OCSPSigning 

OCSP No Check

Dogtag caOCSPCert


https://github.com/dogtagpki/pki/blob/master/base/ca/shared/conf/caOCSPCert.profile

Basic Constraints - CRITICAL

Authority Key ID

Subject Key ID

Key Usage:
  -
  
Extended Key Usage:
    OCSPSigning 

com.netscape.cms.profile.def.OCSPNoCheckExtDefault

February 7, 2020

Tomcat RPM installation on RHEL and CentOS

Introduction

Using a RPM installation from a trusted RPM repository is a huge advantage, since then is life cycle with patching made easy. Otherwise you will have to manage all patching yourself, which in the long run, will always be more costly than using RPM installation from a trusted RPM repository. And you will also be more exposed by security weakness, because you have not a current patched software version.

RHEL 7 and CentoOS 7

Both RHEL 7 and CentOS 7 comes with a ready to use Tomcat 7. The only drawback is that the version is rather old.

But do you really need a newer version? The difference between Servlet 3.0 (part of Java EE 6) and Servlet 4.0 (part of Java EE 8) is quite small.

And if you are using websockets it is the same version of the spec between Tomcat 7 and 9. Other bigger differences is the support for HTTP/2, but do really need this? Maybe you do or you do not. And if you do not use these new feature you are probably fine with an older version of Tomcat.

From a security perspective, the difference between Tomcat 7 and 9 (as long they are patched), are minimal. Alla the security configuration in web.xml are in place in Tomcat 7. See (Mis)Configure web.xml in Java EE 6 . The only new feature in Servlet 4 and web.xml is

default-context-path
request-character-encoding
response-character-encoding
deny-uncovered-http-methods
absolute-ordering (only relevant if you are using web-fragment.xml)

And the difference between security specific feature between Tomcat 7 and 9 are

Tomcat 9 new supports OCSP, but only for Tomcat Native Connector. See https://tomcat.apache.org/tomcat-9.0-doc/ssl-howto.html#Using_OCSP_Certificates
Both Tomcat 7 and 9 both rely on MBean technology for monitoring, which is a problem, since remote JMX connection does not support strong authentication, only username and password and default requires random ports. The random ports can be fixed with catalina-jmx-remote.jar, see Enable JMX Remote in Tomcat 7
Pure Tomcat High Availability (HA) is the same, i.e. 1. replication is the same, but do you really need this, maybe you do or you do not. 2. Pure Tomcat load balancing is seldom used in production. If you are looking for a software solution I recommend using mod_cluster, which works very well. If that is not an option use mod_proxy. Otherwise most people use a hardware load balancer like BigIP F5.
Tomcat 9 still have crazy logging handling. 1. logging to multiple files which make error search hard and general overview of the tomcat health hard. 2. The only project using custom logging handler JULI. Do Java really need another logging framework? Consider using a single log file and Log4J, see Use Log4J in Tomcat 7

Otherwise the good security filter are still the same, such as CORS Filter, CSRF Filter, Expires Filter, Failed Request Filter and HTTP Header Security Filter, see Tomcat 7 Container Provided Filters.

The nest lockout realm, see Tomcat 7 Lockout Realm.


# yum install tomcat

# systemctl restart tomcat; systemctl enable tomcat

# rpm -ql tomcat
/etc/logrotate.d/tomcat
/etc/sysconfig/tomcat
/etc/tomcat
/etc/tomcat/Catalina
/etc/tomcat/Catalina/localhost
/etc/tomcat/catalina.policy
/etc/tomcat/catalina.properties
/etc/tomcat/conf.d
/etc/tomcat/conf.d/README
/etc/tomcat/context.xml
/etc/tomcat/log4j.properties
/etc/tomcat/logging.properties
/etc/tomcat/server.xml
/etc/tomcat/tomcat-users.xml
/etc/tomcat/tomcat.conf
/etc/tomcat/web.xml
/usr/bin/tomcat-digest
/usr/bin/tomcat-tool-wrapper
/usr/lib/systemd/system/tomcat.service
/usr/lib/systemd/system/tomcat@.service
/usr/libexec/tomcat
/usr/libexec/tomcat/functions
/usr/libexec/tomcat/preamble
/usr/libexec/tomcat/server
/usr/sbin/tomcat
/usr/share/doc/tomcat-7.0.76
/usr/share/doc/tomcat-7.0.76/LICENSE
/usr/share/doc/tomcat-7.0.76/NOTICE
/usr/share/doc/tomcat-7.0.76/RELEASE-NOTES
/usr/share/tomcat
/usr/share/tomcat/bin/bootstrap.jar
/usr/share/tomcat/bin/catalina-tasks.xml
/usr/share/tomcat/conf
/usr/share/tomcat/lib
/usr/share/tomcat/logs
/usr/share/tomcat/temp
/usr/share/tomcat/webapps
/usr/share/tomcat/work
/var/cache/tomcat
/var/cache/tomcat/temp
/var/cache/tomcat/work
/var/lib/tomcat
/var/lib/tomcat/webapps
/var/lib/tomcats
/var/log/tomcat
/var/log/tomcat/catalina.out

Configuration:
/etc/tomcat/tomcat.conf
(/etc/sysconfig/tomcat)

# systemctl cat tomcat.service
# /usr/lib/systemd/system/tomcat.service
# Systemd unit file for default tomcat
# 
# To create clones of this service:
# DO NOTHING, use tomcat@.service instead.

[Unit]
Description=Apache Tomcat Web Application Container
After=syslog.target network.target

[Service]
Type=simple
EnvironmentFile=/etc/tomcat/tomcat.conf
Environment="NAME="
EnvironmentFile=-/etc/sysconfig/tomcat
ExecStart=/usr/libexec/tomcat/server start
SuccessExitStatus=143
User=tomcat

[Install]
WantedBy=multi-user.target


# cat /etc/logrotate.d/tomcat 
/var/log/tomcat/catalina.out {
    copytruncate
    weekly
    rotate 52
    compress
    missingok
    create 0644 tomcat tomcat
}

-----------------------------

# mkdir /usr/share/tomcat/webapps/ROOT
# echo "<html><body><h1>TOMCAT ROOT</h1></body></html>" > /usr/share/tomcat/webapps/ROOT/index.html
# chown root:tomcat -Rv /usr/share/tomcat/webapps/
# curl http://127.0.0.1:8080/
<html><body><h1>TOMCAT ROOT</h1></body></html>

-----------------------------
# yum list installed | grep tomcat
tomcat.noarch                     7.0.76-10.el7_7            @rhel-7-server-rpms
tomcat-el-2.2-api.noarch          7.0.76-10.el7_7            @rhel-7-server-rpms
tomcat-jsp-2.2-api.noarch         7.0.76-10.el7_7            @rhel-7-server-rpms
tomcat-lib.noarch                 7.0.76-10.el7_7            @rhel-7-server-rpms
tomcat-servlet-3.0-api.noarch     7.0.76-10.el7_7            @rhel-7-server-rpms

RHEL 8 and CentOS 8

Now too the sad story. Tomcat is no longer available on either RHEL 8 or CentOS 8.

"The Apache Tomcat server has been removed from Red Hat Enterprise Linux. Apache Tomcat is a servlet container for the Java Servlet and JavaServer Pages (JSP) technologies. Red Hat recommends that users requiring a servlet container use the JBoss Web Server."