[Fedora-directory-users] mod_nss OCSP failover to CRL

[sg4all]

Hi,

I'm trying to set up a apache webserver with mod_nss. When available, OCSP
should be used to verify the validity of the certificate. When the OCSP is
unavailable, CRLs are used.

I installed the CRLS, and configured everything. (My nss.conf is included in
this message).

When I comment out "NSSOCSP On": it validates the certificates using CRL
correctly.
When "NSSOCSP on" is used, it validates the certificates using OCSP
correctly.

However, when NSSOCSP is enabled, but I make the OCSP server unavailable
(e.g. by putting an extra entry in /etc/hosts), a request takes a long time
(I guess mod_nss tries a few times to get to the OCSP) and eventually fails.

Is what I want supported? If so, does anyone have a clue what I do wrong?

I tried this on CentOS5.  I tried this configuration file on 2 versions of
mod_nss. First using version  1.0.3-4.el5 which is installed using 'yum
install mod_nss'. I also tried it on version 1.0.8 (which I built from
source)

thanks!

My nss.conf file:
#
# This is the Apache server configuration file providing SSL support using.
# the mod_nss plugin.  It contains the configuration directives to instruct
# the server how to serve pages over an https connection.
#
# Do NOT simply read the instructions in here without understanding
# what they do.  They're here only as hints or reminders.  If you are unsure
# consult the online docs. You have been warned.
#

LoadModule nss_module modules/libmodnss.so

#
# When we also provide SSL we have to listen to the
# standard HTTP port (see above) and to the HTTPS port
#
# Note: Configurations that use IPv6 but not IPv4-mapped addresses need two
#       Listen directives: "Listen [::]:443" and "Listen 0.0.0.0:443"
#
Listen 443

##
##  SSL Global Context
##
##  All SSL configuration in this context applies both to
##  the main server and all SSL-enabled virtual hosts.
##

#
#   Some MIME-types for downloading Certificates and CRLs
#
AddType application/x-x509-ca-cert .crt
AddType application/x-pkcs7-crl    .crl

#   Pass Phrase Dialog:
#   Configure the pass phrase gathering process.
#   The filtering dialog program (`builtin' is a internal
#   terminal dialog) has to provide the pass phrase on stdout.
NSSPassPhraseDialog  builtin

#   Pass Phrase Helper:
#   This helper program stores the token password pins between
#   restarts of Apache.
NSSPassPhraseHelper /usr/sbin/nss_pcache

#   Configure the SSL Session Cache.
#   NSSSessionCacheSize is the number of entries in the cache.
#   NSSSessionCacheTimeout is the SSL2 session timeout (in seconds).
#   NSSSession3CacheTimeout is the SSL3/TLS session timeout (in seconds).
NSSSessionCacheSize 10000
NSSSessionCacheTimeout 100
NSSSession3CacheTimeout 86400

#
# Pseudo Random Number Generator (PRNG):
# Configure one or more sources to seed the PRNG of the SSL library.
# The seed data should be of good random quality.
# WARNING! On some platforms /dev/random blocks if not enough entropy
# is available. Those platforms usually also provide a non-blocking
# device, /dev/urandom, which may be used instead.
#
# This does not support seeding the RNG with each connection.

NSSRandomSeed startup builtin
#NSSRandomSeed startup file:/dev/random  512
#NSSRandomSeed startup file:/dev/urandom 512

##
## SSL Virtual Host Context
##

<VirtualHost _default_:443>

#   General setup for the virtual host
#DocumentRoot "/etc/httpd/htdocs"
#ServerName www.example.com:443
#ServerAdmin [e-mail]

# Use separate log files for the SSL virtual host; note that LogLevel
# is not inherited from httpd.conf.
#ErrorLog /etc/httpd/logs/nss_error_log
#TransferLog /etc/httpd/logs/nss_access_log
LogLevel debug

#   SSL Engine Switch:
#   Enable/Disable SSL for this virtual host.
NSSEngine on

#   SSL Cipher Suite:
#   List the ciphers that the client is permitted to negotiate.
#   See the mod_nss documentation for a complete list.

# SSL 3 ciphers. SSL 2 is disabled by default.
NSSCipherSuite
+rsa_rc4_128_md5,+rsa_rc4_128_sha,+rsa_3des_sha,-rsa_des_sha,-rsa_rc4_40_md5,-rsa_rc2_40_md5,-rsa_null_md5,-rsa_null_sha,+fips_3des_sha,-fips_des_sha,-fortezza,-fortezza_rc4_128_sha,-fortezza_null,-rsa_des_56_sha,-rsa_rc4_56_sha,+rsa_aes_128_sha,+rsa_aes_256_sha

#NSSCipherSuite -ALL:SSLv3+HIGH:-aNULL

# SSL 3 ciphers + ECC ciphers. SSL 2 is disabled by default.
#
# Comment out the NSSCipherSuite line above and use the one below if you
have
# ECC enabled NSS and mod_nss and want to use Elliptical Curve Cryptography
#NSSCipherSuite
+rsa_rc4_128_md5,+rsa_rc4_128_sha,+rsa_3des_sha,-rsa_des_sha,-rsa_rc4_40_md5,-rsa_rc2_40_md5,-rsa_null_md5,-rsa_null_sha,+fips_3des_sha,-fips_des_sha,-fortezza,-fortezza_rc4_128_sha,-fortezza_null,-rsa_des_56_sha,-rsa_rc4_56_sha,+rsa_aes_128_sha,+rsa_aes_256_sha,-ecdh_ecdsa_null_sha,+ecdh_ecdsa_rc4_128_sha,+ecdh_ecdsa_3des_sha,+ecdh_ecdsa_aes_128_sha,+ecdh_ecdsa_aes_256_sha,-ecdhe_ecdsa_null_sha,+ecdhe_ecdsa_rc4_128_sha,+ecdhe_ecdsa_3des_sha,+ecdhe_ecdsa_aes_128_sha,+ecdhe_ecdsa_aes_256_sha,-ecdh_rsa_null_sha,+ecdh_rsa_128_sha,+ecdh_rsa_3des_sha,+ecdh_rsa_aes_128_sha,+ecdh_rsa_aes_256_sha,-echde_rsa_null,+ecdhe_rsa_rc4_128_sha,+ecdhe_rsa_3des_sha,+ecdhe_rsa_aes_128_sha,+ecdhe_rsa_aes_256_sha

#NSSProtocol SSLv3,TLSv1
NSSProtocol -ALL +SSLv3 +TLSv1
#   SSL Certificate Nickname:
#   The nickname of the RSA server certificate you are going to use.
NSSNickname Server-Cert

#   SSL Certificate Nickname:
#   The nickname of the ECC server certificate you are going to use, if you
#   have an ECC-enabled version of NSS and mod_nss
#NSSECCNickname Server-Cert-ecc

#   Server Certificate Database:
#   The NSS security database directory that holds the certificates and
#   keys. The database consists of 3 files: cert8.db, key3.db and secmod.db.
#   Provide the directory that these files exist.
NSSCertificateDatabase /etc/httpd/alias

#   Database Prefix:
#   In order to be able to store multiple NSS databases in one directory
#   they need unique names. This option sets the database prefix used for
#   cert8.db and key3.db.
#NSSDBPrefix my-prefix-

#   Client Authentication (Type):
#   Client certificate verification type.  Types are none, optional and
#   require.
NSSVerifyClient require

#
#   Online Certificate Status Protocol (OCSP).
#   Verify that certificates have not been revoked before accepting them.
NSSOCSP On

#   Access Control:
#   With SSLRequire you can do per-directory access control based
#   on arbitrary complex boolean expressions containing server
#   variable checks and other lookup directives.  The syntax is a
#   mixture between C and Perl.  See the mod_nss documentation
#   for more details.
#<Location />
#NSSRequire (    %{SSL_CIPHER} !~ m/^(EXP|NULL)/ \
#            and %{SSL_CLIENT_S_DN_O} eq "Snake Oil, Ltd." \
#            and %{SSL_CLIENT_S_DN_OU} in {"Staff", "CA", "Dev"} \
#            and %{TIME_WDAY} >= 1 and %{TIME_WDAY} <= 5 \
#            and %{TIME_HOUR} >= 8 and %{TIME_HOUR} <= 20       ) \
#           or %{REMOTE_ADDR} =~ m/^192.76.162.[0-9]+$/
#</Location>

#   SSL Engine Options:
#   Set various options for the SSL engine.
#   o FakeBasicAuth:
#     Translate the client X.509 into a Basic Authorisation.  This means
that
#     the standard Auth/DBMAuth methods can be used for access control.  The
#     user name is the `one line' version of the client's X.509 certificate.
#     Note that no password is obtained from the user. Every entry in the
user
#     file needs this password: `xxj31ZMTZzkVA'.
#   o ExportCertData:
#     This exports two additional environment variables: SSL_CLIENT_CERT and
#     SSL_SERVER_CERT. These contain the PEM-encoded certificates of the
#     server (always existing) and the client (only existing when client
#     authentication is used). This can be used to import the certificates
#     into CGI scripts.
#   o StdEnvVars:
#     This exports the standard SSL/TLS related `SSL_*' environment
variables.
#     Per default this exportation is switched off for performance reasons,
#     because the extraction step is an expensive operation and is usually
#     useless for serving static content. So one usually enables the
#     exportation for CGI and SSI requests only.
#   o StrictRequire:
#     This denies access when "NSSRequireSSL" or "NSSRequire" applied even
#     under a "Satisfy any" situation, i.e. when it applies access is denied
#     and no other module can change it.
#   o OptRenegotiate:
#     This enables optimized SSL connection renegotiation handling when SSL
#     directives are used in per-directory context.
NSSOptions +FakeBasicAuth +ExportCertData +StrictRequire
##<Files ~ ".(cgi|shtml|phtml|php3?)$">
 #   NSSOptions +StdEnvVars
#</Files>
#<Directory "/var/www/cgi-bin">
 #   NSSOptions +StdEnvVars
#</Directory>

#   Per-Server Logging:
#   The home of a custom SSL log file. Use this when you want a
#   compact non-error SSL logfile on a virtual host basis.
#CustomLog /home/rcrit/redhat/apache/logs/ssl_request_log \
#          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x "%r" %b"

</VirtualHost>
<Location "/">
 NSSRequireSSL
</Location>