WASD implements SSL using a freely available software toolkit supported by the OpenSSL Project, in particular the VMS port, to which Richard Levitte (levitte@lp.se) and Robert Byer (ByerRA@aol.com) have been significant contributors.
[next] [previous] [contents] [full-page]17.1 - SSL Functionality Sources
17.2 - WASD SSL Quick-Start
17.3 - SSL Configuration
17.3.1 - HTTPD$CONFIG [Service]
17.3.2 - HTTPD$SERVICE
17.3.3 - SSL Server Certificate
17.3.4 - SSL Private key
17.3.5 - SSL Virtual Services
17.3.6 - SSL Access Control
17.3.7 - Authorization Using X.509 Certification
17.3.8 - Features
17.3.9 - X509 Configuration
17.3.10 - Certificate Authority Verification File
17.3.11 - X.509 Authorization CGI Variables
17.4 - Certificate Management
17.4.1 - Server Certificate
17.4.2 - Client Certificate
17.4.3 - Certificate Signing Request
17.5 - SSL CGI Variables
17.6 - SSL References
This section is not a tutorial on SSL. It contains only information relating to WASD's use of it. Refer to the listed references, 17.6 - SSL References, for further information on SSL technology.
The Secure Sockets Layer protocol (SSL) is designed to provide a secure channel between two communicating applications, in the case of HTTP between the browser (client) and the HTTPd (server). It also authenticates server and optionally client identity. SSL operates by establishing an encrypted communication path between the two applications, "wrapping" the entire application protocol inside the secure link, providing complete privacy for the entire transaction. In this way security-related data such as user identification and password, as well as sensitive transaction information can be effectively protected from unauthorized access while in transit.
SSL functionality is not supplied with the basic WASD package. In part this is due to the relative bulk of this component, but also considers potential patent issues and export restrictions on some cryptography technology in some jurisdictions.
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WASD implements SSL using a freely available software toolkit supported by the OpenSSL Project, in particular the VMS port, to which Richard Levitte (levitte@lp.se) and Robert Byer (ByerRA@aol.com) have been significant contributors. |
OpenSSL is a continuing development of the SSLeay toolkit (pronounced "S-S-L-E-A-Y", i.e. all letters spelt), authored by Eric Young and Tim Hudson. OpenSSL licensing allows unrestricted commercial and non-commercial use. This toolkit is in use regardless of whether the WASD OpenSSL package, HP SSL for OpenVMS Alpha, IA64 and (now - late 2003) VAX product, or other stand-alone OpenSSL environment is installed.
It is always preferable to move to the latest support release of OpenSSL
as known bugs in previous versions are progressively addressed (ignoring the
issue of new bugs being introduced ;^).
Cryptography Software
Be aware that export/import and/or use of cryptography software, or even
just providing cryptography hooks, is illegal in some parts of the world. When
you re-distribute this package or even email patches/suggestions to the author
or other people PLEASE PAY CLOSE ATTENTION TO ANY APPLICABLE
EXPORT/IMPORT LAWS. The author of this package is not liable for any
violations you make here.
Some Thoughts From R. S. Engelschall
Ralf S. Engelschall (rse@engelschall.com) is the author of the popular Apache mod_ssl package. This section is taken from the mod_ssl read-me and is well-worth some consideration for this and software security issues in general.
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SSL adds a significant overhead to an HTTP transaction for the following reasons.
For these reasons SSL HTTP is slower and has far greater impact
on the server system CPU than standard HTTP and therefore should only be
used when transaction privacy is required, not as a general HTTP service.
Also, if a general HTTP and an SSL HTTP service is provided on a
multi-processor system, with one or other or both experiencing significant
traffic, then the two services should be run in separate processes.
Interoperability
WASD SSL has been used against a wide variety of browsers and certificates. Most combinations work. Some do not, usually related to the level of encryption required by some certificates precluding export-grade browsers from connecting.
To date OpenSSL certificates, and those from Thawte and VeriSign have been deployed on WASD servers.
WASD supports both 40bit, USA "export-grade" encryption, as well as 128-bit, full-strength, USA "domestic-grade" encryption. Note that as of early 2000, 128-bit USA domestic-grade encryption has been generally available due to changes in USA Federal Government export restriction policy. Netscape Navigator 4.73 and Microsoft Internet Explorer 5.5 and later now provide this level of encryption as standard.
The "/SSL" qualifier controls which version(s) of the SSL protocol
the server will support; "2", "3" or "23" (i.e. versions 2
and 3, also the default). Using /NOSSL disables the SSL functionality of an
SSL executable. There are also per-service configuration directives for
tailoring the protocol version.
HTTP-to-SSL Gateway
The WASD proxy service can provide an HTTP-to-SSL gateway, allowing
standard HTTP clients to connect to Secure Sockets Layer services. See
16.5.4 - Originating SSL.
17.1 - SSL Functionality Sources
Secure Sockets Layer functionality is easily integrated into WASD and is available from one (or more) of three sources. See 17.2 - WASD SSL Quick-Start for the basics of installing WASD SSL and 17.3 - SSL Configuration for configuration of various aspects.
http://www.openvms.compaq.com/openvms/products/ssl/ssl.html
This is provided from the directory
SYS$COMMON:[SSL]containing shared libraries, executables and templates for certificate management, etc. If this product is installed and started up the WASD installation and update procedures should detect it and provide the option of compiling and/or linking WASD against it's sharable libraries.
WASD SSL installation creates an OpenSSL directory in the source area
HT_ROOT:[SRC.OPENSSL-n_n_n] (look for it here)containing the OpenSSL copyright notice, object libraries, object modules for building executables, example certificates, and some other support files and documentation.
SSL functionality can be installed with a new package, or with an update, or it can be added to an existing non-SSL enabled site. The following steps give a quick outline for support of SSL.
$ UNZIP -z device:[dir]archive.ZIP
$ SET DEFAULT HT_ROOT:[000000] $ UNZIP "-V" device:[dir]archive.ZIP
$ @HT_ROOT:[INSTALL]UPDATE SSL
It is also possible to check the SSL package at any other time using the
server demonstration procedure. It is necessary to specify that it is to use
the SSL executable. Follow the displayed instructions.
$ @HT_ROOT:[INSTALL]DEMO.COM SSL
[Service] the.host.name https://the.host.name
$ HTTPD /DO=EXIT $ @HT_ROOT:[STARTUP]STARTUP
http://the.host.name/
https://the.host.name/
The example HTTPd startup procedure already contains support for the SSL executable. If this has been used as the basis for startup then an SSL executable will be started automatically, rather than the standard executable. The SSL executable supports both standard HTTP services (ports) and HTTPS services (ports). These must be configured using the [service] parameter. SSL services are distinguished by specifying "https:" in the parameter. The default port for an SSL service is 443.
WASD can configure services using the HTTPD$CONFIG [service] directive, the
HTTPD$SERVICE configuration file, or even the /SERVICE= qualifier.
17.3.1 - HTTPD$CONFIG [Service]
The following example illustrates creating two services using the
HTTPD$CONFIG [Service] directive; a standard HTTP service on the default port
80, and an SSL service on the default port 443.
[Service]
alpha.host.name
https://alpha.host.name
The one further requirement of an SSL server is a certificate.
By default this is located using the HTTPD$SSL_CERT logical name during
startup, however if required, each SSL service can have an individual
certificate configured against it using the syntax shown in this example.
[Service]
alpha.host.name
https://alpha.host.name;cert=ht_root:[local]alpha.pem
https://beta.host.name;cert=ht_root:[local]beta.pem
17.3.2 - HTTPD$SERVICE
SSL service configuration using the HTTPD$SERVICE configuration is slightly
simpler, with a specific configuration directive for each aspect. See
9 - Service Configuration. This example illustrates configuring
the same services as used in the previous section.
[[http://alpha.host.name:80]]
[[https://alpha.host.name:443]]
[ServiceSSLcert] ht_root:[local]alpha.pem
[[https://beta.host.name:443]]
[ServiceSSLcert] ht_root:[local]beta.pem
17.3.3 - SSL Server Certificate
The server certificate is used by the browser to authenticate the server
against the server certificate Certificate Authority (CA), in making a secure
connection, and in establishing a trust relationship between the browser and
server. By default this is located using the HTTPD$SSL_CERT logical name
during startup, however if required, each SSL service can have an individual
certificate configured against it as shown above.
17.3.4 - SSL Private key
The private key is used to validate and enable the server certificate. A private key is enabled using a secret, a password. It is common practice to embed this (encrypted) password within the private key data. This private key can be appended to the server certificate file, or it can be supplied separately. If provided separately it is by default located using the HTTPD$SSL_KEY logical, though can be specified on a per-service basis. When the password is embedded in the private key information it becomes vulnerable to being stolen as an enabled key. For this reason it is possible to provide the password separately and manually.
If the password key is not found with the key during startup the server will request that it be entered at the command-line. This request is made via the HTTPDMON "STATUS:" line (23.8 - HTTPd Monitor), and if any OPCOM category is enabled via an operator message (6.10 - OPCOM Logging). If the private key password is not available with the key it is recommended that OPCOM be configured, enabled and monitored at all times.
When a private key password is requested by the server it is supplied using
the /DO=SSL=KEY=PASSWORD directive (5.5.2 - Server Command Line Control). This
must be used at the command line on the same system as the server is executing.
The server then prompts for the password.
Enter private key password []:
The password is not echoed. When entered the password is securely
supplied to the server and startup progresses. An incorrect password will be
reprompted for twice (i.e. up to three attempts are allowed) before the startup
continues with the particular service not configured and unavailable. Entering
a password consisting of all spaces will cause the server to abort the full
startup and exit from the system.
17.3.5 - SSL Virtual Services
Multiple virtual SSL services (https:) sharing the same certificate (and other characteristics) can essentially be configured against any host name (unique IP address or host name alias) and/or port in the same way as standard services (http:). Services requiring unique certificates can only be configured for the same port number against individual and unique IP addresses (i.e. not against aliases).
This is not a WASD restriction, it applies to all servers for significant technical reasons. Secure Sockets Layer is designed to wrap an entire application protocol (in this case HTTP). HTTP virtual services use the "Host:" field of the request header to determine which service the client intended to use. This requires the network connection established and at least the request header transfered and processed. For an SSL service establishing the connection requires a complex transaction involving, amongst other things, certificate exchange. Hence, the certificate (and all other SSL parameters) must be determined at the time the server accepts the initial connection request. At that point the only defining characteristics can be IP address and port, and therefore services requiring unique certificates must be unique either by address or port. Services sharing certificates do not have this restriction and so may be configured against host name aliases.
For example, unique certificates for https://www.company1.com:443/ and
https://www.company2.com:443/ can be configured only if COMPANY1 and COMPANY2
have unique IP addresses. If COMPANY2 is an host name alias for COMPANY1 they
must share the same certificate. During startup service configuration the
server checks for such conditions, forces subsequent services to use the same
SSL characteristsics as the first configured, and issues a warning about this
"sharing".
17.3.6 - SSL Access Control
When authorization is in place (15 - Authentication and Authorization)
access to username/password controlled data/functionality benefits enormously
from the privacy of an authorization environment inherently secured via the
encrypted communications of SSL. In addition there is the possibility of
authentication via client X.509 certification
(17.3.7 - Authorization Using X.509 Certification). SSL may be used as part of the site's
access control policy, as whole-of-site, see 15.2 - Authentication Policy, or
on a per-path basis, see 13.7 - Conditional Mapping and
Access Restriction List.
17.3.7 - Authorization Using X.509 Certification
The server access control functionality (authentication and authorization) allows the use of public key infrastructure (PKI) X.509 v3 client certificates for establishing identity and based on that apply authorization constraints. See 15 - Authentication and Authorization for general information on WASD authorization and 15.4 - Authorization Configuration File for configuring a X509 realm. 17.6 - SSL References provides introductory references on public-key cryptography and PKI.
A client certificate is stored by the browser. During an SSL transaction the server can request that such a certificate be provided. For the initial instance of such a request the browser activates a dialog requesting the user select one of any certificates it has installed. If selected it is transmitted securely to the server which will usually (though optionally not) authenticate it's Certificate Authority to establish it's integrity. If accepted it can then be used as an authenticated identity. This obviates the use of username/password dialogs.
Important
Neither username/password nor certificate-based authentication addresses security issues related to access to individual machines and stored certificates, or to password confidentiality. Public-key cryptography only verifies that a private key used to sign some data corresponds to the public key in a certificate. It is a user responsibility to protect a machine's physical security and to keep private-key passwords secret.
The initial negotiation and verification of a client certificate is a
relatively resource intensive process. Once established however, OpenSSL
sessions are stored in a cache, reducing subsequent request overheads
significantly. Each cache entry has a specified expiry period after which the
client is forced to negotiate a new session. This period is adjustable using
the "[LT:integer]" and "[TO:integer]" directives described below.
17.3.8 - Features
WASD provides a range of capabilities when using X.509 client certificates.
Of course, the WASD SSL component must be installed and in use to apply
client X.509 certificate authorization. There is general server setup, then
per-service and per-resource configuration.
General Setup
Client certificate authorization has reasonable defaults. If some aspect requires site refinement the following /SSL= qualifier parameters can provide per-server defaults.
The location of the CA verification file can also be determined using the logical name HTTPD$SSL_CAFILE. The order of precedence for using these specifications is
To enable client certification for all requests on a per-service basis the
following HTTPD$CONFIG directive may be used. A non-default CA verification
file can also optionally be supplied.
[Service]
https://the.host.name;verify
https://the.host.name;cafile=HT_ROOT:[LOCAL]CA_THE_HOST_NAME.TXT
When HTTPD$SERVICE is in use a service-specific directive is provided for
both per-service verification and per-service CA file specification (allowing
different services to accept a different mix of CAs).
[[https://the.host.name:443]]
[ServiceSSLclientVerifyRequired] enabled
[ServiceSSLclientCAfile] HT_ROOT:[LOCAL]CA_THE_HOST_NAME.TXT
By Resource
Client certificate authorization is probably most usefully applied on a
per-resource (per-request-path) basis using HTTPD$AUTH configuration file
rules. Of course, per-resource control also applies to services that always
require a client certificate (the only difference is the certificate has
already been negotiated for during the initial connection handshake). The
reserved realm name "X509" activates client certificate authentication
when a rule belonging to that realm is triggered. The following example shows
such a rule providing read access to those possessing any verified certificate.
[X509]
/path/requiring/cert/* r
Optional directives may be supplied to the X.509 authenticator controlling
what mode the certificate is accepted in, as well a further access-restriction
rules on specifically which certificates may or may not be accepted for
authorization. Such directives are passed via the "param=" mechanism.
The following real-life example shows a script path requiring a mandatory
certificate, but not necessarily having the CA verified. This would allow a
certificate display service to be established, the "[to:EXPIRED]"
directive forcing the client to explicitly select a certificate with each
access.
[X509]
/cgi-bin/client_cert_details r,param="[vf:OPTIONAL][to:EXPIRED]"
A number of such directives are available controlling some aspects of the certificate negotiation and verification. The "[LT:integer]" directive causes a verified certificate selection to continue to be valid for the specified period as long as requests continue during that period (lifetime is reset with each access).
Optional "param=" passed conditionals may also be used to provide additional filtering on which certificates may or may not be used against the particular path. This is based on pattern matching against client certificate components.
These function and can be used in a similar fashion to mapping rule conditionals (13.7 - Conditional Mapping). This includes the logical ORing, ANDing and negating of conditionals. Asterisk wildcards match any zero or more characters, percent characters any single character. Matching is case-insensitive.
Note that the "IS:" and "SU:" conditionals each have a specific-record and an entire-field mode. If the conditional string begins with a slash then it is considered to be a match against a specified record contents within the field. If it begins with a wildcard then it is matched against the entire field contents. Certificate DN records recognised by WASD,
The following (fairly contrived) examples provide an illustration of the
basics of X509 conditionals. When matching against Issuer and Subject DNs some
knowlege of their contents and structure is required (see
17.6 - SSL References for some basic resources).
[X509]
# only give "VeriSign"ed ones access
/controlled/path1/* r+w,param="[IS:/O=VeriSign\ Inc.]"
# only give non-"VeriSign"ed ones access
/controlled/path2/* r+w,param="[!IS:/O=VeriSign\ Inc.]"
# only allow 128 bit keys using RC4-MD5 access
/controlled/path3/* r+w,param="[KS:128][CI:RC4-MD5]"
# only give a "Thawte"-signed client based in Australia
# with the following email address access
/controlled/path4/* r+w,param="\
[IS:*/O=Thawte\ Consulting\ cc/*]\
[SU:*/C=AU/*/Email=mark.daniel@wasd.vsm.com.au*]"
# use the subject DN common-name record as the remote-user name
# furthermore, restrict the CA's allowed to be used this way
/VMS/* r+w,param="[RU:/CN=][IS:/O=WASD\ HTTPd\ CA\ Cert]"
Of course, access control via group membership is also available. The
effective username for the list is the 32 digit fingerprint of the
client certificate (shown as REMOTE_USER IN the first example of
17.3.11 - X.509 Authorization CGI Variables), or the Subject DN record as specified using
the [RU:/record=] directive. This may be entered into simple lists
as part of a group of which membership then controls access to the resource.
The following examples show the contents of simple list files containing the
X.509 fingerprints, derived remote-user names, and the required HTTPD$AUTH
realm entries.
# FINGERPRINTS.$HTL
# (a file of X.509 fingerprints for access to "/path/requiring/cert/")
106C8342890A1703AAA517317B145BF7 mark.daniel@wasd.vsm.com.au
6ADA07108C20338ADDC3613D6D8B159D just.another@where.ever.com
# CERT_CN.$HTL
# (a file of X.509 remote-user names derived using [RU:/CN=]
Mark_Daniel mark.daniel@wasd.vsm.com.au
Just_Another just.another@where.ever.com
[X509;FINGERPRINTS=list]
/path/requiring/cert/* r+w
[X509;CERT_CN=list]
/path/requiring/cn/* r+w
In a similar fashion the effective username can be placed in an access
restriction list. The following configuration would only allow the user of
the certificate access to the specified resources. Other verified certificate
holders would be denied access.
[X509]
/httpd/-/admin/* ~106C8342890A1703AAA517317B145BF7,r+w
/ht_root/local/* ~106C8342890A1703AAA517317B145BF7,r+w
/other/path/* ~Mark_Daniel,r+w,param="[ru:/cn=]"
/yet/another/path/* ~Just_Another,r+w,param="[ru:/cn=]"
17.3.10 - Certificate Authority Verification File
For the CA certificate component of the client certificate to be verified as being what it claims to be (and thus establishing the integrity of the client certificate) a list of such certificates must be provided for comparison purposes. For WASD this list is contained in a single, plain-text file variously specified using either the HTTPD$SSL_CAFILE logical or per-service ";cafile=" or "[ServiceSSLclientCAfile]" directives.
Copies of CA certificates are available for such purposes. The PEM copies (base-64 encoded versions of the binary certificate) can be placed into this file using any desired text editor. Comments may be inserted by prefixing with the "#" or "!" characters. For WASD this would be best stored in the HT_ROOT:[LOCAL] directory, or site equivalent.
An example of how such a file appears is provided below (ellipses inserted
to reduce the bulk of example). There is one of these per certificate
authority.
################################################################
Verisign Class 1 Public Primary Certification Authority
=======================================================
MD5 Fingerprint: 97:60:E8:57:5F:D3:50:47:E5:43:0C:94:36:8A:B0:62
PEM Data:
-----BEGIN CERTIFICATE-----
MIICPTCCAaYCEQDNun9W8N/kvFT+IqyzcqpVMA0GCSqGSIb3DQEBAgUAMF8xCzAJ
BgNVBAYTAlVTMRcwFQYDVQQKEw5WZXJpU2lnbiwgSW5jLjE3MDUGA1UECxMuQ2xh
c3MgMSBQdWJsaWMgUHJpbWFyeSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTAeFw05
...
FvjqBUuUfx3CHMjjt/QQQDwTw18fU+hI5Ia0e6E1sHslurjTjqs/OJ0ANACY89Fx
lA==
-----END CERTIFICATE-----
Certificate Ingredients:
Data:
Version: 1 (0x0)
Serial Number:
cd:ba:7f:56:f0:df:e4:bc:54:fe:22:ac:b3:72:aa:55
Signature Algorithm: md2WithRSAEncryption
Issuer: C=US, O=VeriSign, Inc., OU=Class 1 Public Primary
...
35:b0:7b:25:ba:b8:d3:8e:ab:3f:38:9d:00:34:00:98:f3:d1:
71:94
################################################################
The WASD SSL package provides an example CA verification file constructed
from all the certificates provided in Netscape Navigator CERT7.DB file. This
has been generated for and obtained from the Apache mod_ssl
package, being used for the same purpose with that. The WASD file name is
CA-BUNDLE_CRT.TXT and is usually located in HT_ROOT:[LOCAL]. The exact date
and mod_ssl version it was obtained from can be found in the
opening commentary of the file itself. The contents of this file can easily be
pared down to the minimum certificates required for any given site. The more
certificates in the file the greater the overhead in verifying any given
client.
17.3.11 - X.509 Authorization CGI Variables
CGI variables specific to client certificate authorization are always
generated for use by scripts and SSI documents. These along with the general
WASD authorization variables are shown in the example below. Note, that due to
length of particular items some in this example are displayed wrapped.
WWW_AUTH_ACCESS == "READ+WRITE"
WWW_AUTH_GROUP == ""
WWW_AUTH_REALM == "X509"
WWW_AUTH_REALM_DESCRIPTION == "X509 Client Certs"
WWW_AUTH_TYPE == "X509"
WWW_AUTH_USER == "Mark Daniel, mark.daniel@wasd.vsm.com.au"
WWW_AUTH_X509_CIPHER == "RC4-MD5"
WWW_AUTH_X509_FINGERPRINT == "10:6C:83:42:89:0A:17:03:AA:A5:17:31:7B:14:5B:F7"
WWW_AUTH_X509_ISSUER == "/O=VeriSign, Inc./OU=VeriSign Trust
Network/OU=www.verisign.com/repository/RPA Incorp. By
Ref.,LIAB.LTD(c)98/CN=VeriSign Class 1 CA Individual Subscriber-Persona Not
Validated"
WWW_AUTH_X509_KEYSIZE == "128"
WWW_AUTH_X509_SUBJECT == "/O=VeriSign, Inc./OU=VeriSign Trust
Network/OU=www.verisign.com/repository/RPA Incorp. by
Ref.,LIAB.LTD(c)98/OU=Persona Not Validated/OU=Digital ID Class 1 - Netscape
/CN=Mark Daniel/Email=mark.daniel@wasd.vsm.com.au"
WWW_REMOTE_USER == "106C8342890A1703AAA517317B145BF7"
Other CGI variables optionally may be enabled using HTTPD$MAP mapping
rules. See 17.5 - SSL CGI Variables. Specific client certificate variables
providing the details of such certificates are available with
SSLCGI=apache_mod_ssl. These are of course in addition to the more general
apache_mod_ssl variables described in the above section. Note that where some
ASN.1 records are duplicated (as in SSL_CLIENT_S_DN) some variables will
contain newline characters (0x10) between those elements (e.g.
SSL_CLIENT_S_DN_OU). The line breaks in this example do not necesarily reflect
those characters.
WWW_SSL_CLIENT_A_KEY == "rsaEncryption"
WWW_SSL_CLIENT_A_SIG == "md5WithRSAEncryption"
WWW_SSL_CLIENT_I_DN == "/O=VeriSign, Inc./OU=VeriSign Trust Network
/OU=www.verisign.com/repository/RPA Incorp. By Ref.,LIAB.LTD(c)98
/CN=VeriSign Class 1 CA Individual Subscriber-Persona Not Validated"
WWW_SSL_CLIENT_I_DN_CN == "VeriSign Class 1 CA Individual Subscriber-Persona
Not Validated"
WWW_SSL_CLIENT_I_DN_O == "VeriSign, Inc."
WWW_SSL_CLIENT_I_DN_OU == "VeriSign Trust Network
www.verisign.com/repository/RPA Incorp. By Ref.,LIAB.LTD(c)98"
WWW_SSL_CLIENT_M_SERIAL == "0BF233D4FE232A90F3F98B2CE0D7DADA"
WWW_SSL_CLIENT_M_VERSION == "3"
WWW_SSL_CLIENT_S_DN == "/O=VeriSign, Inc./OU=VeriSign Trust Network
/OU=www.verisign.com/repository/RPA Incorp. by Ref.,LIAB.LTD(c)98
/OU=Persona Not Validated/OU=Digital ID Class 1 - Netscape
/CN=Mark Daniel/Email=mark.daniel@wasd.vsm.com.au"
WWW_SSL_CLIENT_S_DN_CN == "Mark Daniel"
WWW_SSL_CLIENT_S_DN_EMAIL == "mark.daniel@wasd.vsm.com.au"
WWW_SSL_CLIENT_S_DN_O == "VeriSign, Inc."
WWW_SSL_CLIENT_S_DN_OU == "VeriSign Trust Network
www.verisign.com/repository/RPA Incorp. by Ref.,LIAB.LTD(c)98
Persona Not Validated.Digital ID Class 1 - Netscape"
WWW_SSL_CLIENT_V_END == "Feb 10 23:59:59 2001 GMT"
WWW_SSL_CLIENT_V_START == "Dec 12 00:00:00 2000 GMT"
17.4 - Certificate Management
This is not a tutorial on X.509 certificates and their management. Refer to the listed references, 17.6 - SSL References, for further information on this aspect. It does provide some basic guidelines.
Certificates identify something or someone, associating a public cryptographic key with the identity of the certificate holder. It includes a distinguished name, identification and signature of the certificate authority (CA, the issuer and guarantor of the certificate), and the period for which the certificate is valid, possibly with other, additional information.
The three types of certificates of interest here should not be confused.
The various OpenSSL tools are available for management of all of these certificate types in each of the three SSL environments.
$ @SSL$COM:SSL$CERT_TOOL.COM
S S L C e r t i f i c a t e T o o l
Main Menu
1. View a Certificate
2. View a Certificate Signing Request
3. Create a Certificate Signing Request
4. Create a Self-Signed Certificate
5. Create a CA (Certification Authority) Certificate
6. Sign a Certificate Signing Request
7. Hash Certificates
8. Hash Certificate Revocations
9. Exit
Enter Option:
HT_ROOT:[SRC.OPENSSL-n_n_n.WASD] (look for it here)directory for some procedure-driven support of these activities.
The server uses a certificate to establish it's identity during the initial phase of the SSL protocol exchange. Each server should have a unique certificate. An example certificate is provided with the WASD SSL package. If this is not available (for instance when using the HP SSL for OpenVMS Alpha/IA64/VAX product) then the server will fallback to an internal, default certificate that allows SSL functionality even when no external certification is available. If a "live" SSL site is required a unique certificate issued by a third-party Certificate Authority is desirable.
A working alternative to obtaining one of these certificates is provided by the WASD support DCL procedures, which are quick hacks to ease the production of certificates on an ad hoc basis. In all cases it is preferable to directly use the utilities provided with OpenSSL, but the documentation tends to be rather sparse.
The first requirement may be a tailored "Certificate Authority"
certificate. As the Certificate Authority is non-authoritative (not trying to be
too oxymoronic, i.e. not a well-known CA) these certificates have little value
except to allow SSL transactions to be established with trusting clients.
More commonly "Server Certificates" for specific host names are
required.
Loading Authority Certificates
CA certificates can be loaded into browsers to allow sites using that CA to be accessed by that browser without further dialog. Both Netscape Navigator (v3.n & v4.n, v5.n, v6.n) and MS Internet Explorer (v4.n, v5.n) automatically invokes a server certificate load dialog when it encounters a site using a valid but unknown server certificate.
A manual load is accomplished by requesting the certificate in a format appropriate to the particular browser. This triggers a browser dialog with the user to confirm or refuse the loading of that certificate into the browser Certificate Authority database.
To facilitate loading CA certificates into a browser ensure the following
entries are contained in the HTTP$CONFIG configuration file:
[AddIcon]
/httpd/-/binary.gif [BIN] application/x-x509-ca-cert
[AddType]
.CRT application/x-x509-ca-cert - DER certifcate (MSIE)
.PEM application/x-x509-ca-cert - Privacy Enhanced Mail certificate
Then just provide a link to the required certificate file(s), and click.
Navigator should be able to load using either certificate format. MSIE
v3.n will load and report on the ".CRT" certificate quite
contentedly, but then will not allow it to be used because it does not
represent a well-known Certficate Authority. MSIE v4.n and
v5.n seem able to use the ".CRT" certificate.
Changing Server Certificates
If a site's server (or CA certificate) is changed and the server restarted
any executing browsers will probably complain (Netscape Navigator reports an
I/O error). In this case open the browser's certificate database and delete
any relevant, permanently stored certificate entry, then close and restart the
browser. The next access should initiate the server certificate dialog, or the
CA certificate may be explicitly reloaded.
17.4.2 - Client Certificate
As with server certificates, client certficates are best obtained from a
recognised Certificate Authority. However, for testing and experimental
purposes WASD provides some elementary CGI scripts and DCL procedures to assist
in locally generating X.509 client certificates and installing them into user
browsers.
Manual Generation
The OpenSSL CA certificate generation utility can be used at the command
line to process a CSR. That CSR could have been generated via an online HTML
form.
Semi-Automatic Generation
Using this approach the user generates a Certificate Signing Request (CSR) online, which is then further processed off-line, at the discretion of the site administrator. Only Netscape browsers are supported for what is described below.
A basic DCL procedure providing such a facility is
HT_ROOT:[SRC.OPENSSL-n_n_n.WASD]CLIENT_CERT_REQUEST.COM
This semi-automatic method would probably be the author's preference over
the on-demand approach (see below).
Generation On-Demand
Automatic, on-demand client certificate generation allows any user (subject to access controls) to generate a client certificate automatically via an online service. While this may not generally be a useful thing for a site to provide there may be occasions for it's use. It is a three part process. Only Netscape browsers are supported for what is described below.
HT_ROOT:[SRC.OPENSSL-n_n_n.WASD]CLIENT_CERT_REQUEST.COM(and yes, it's the same procedure as used with the semi-automatic approach, just configured differently).
Recognised Certificate Authorities (CAs) such as Thawte and VeriSign publish lists of requirements for obtaining a server certificate. These often include such documents required to prove organisational name and the right to use the domain name being requested. Check the particular vendor for the exact requirements.
In addition, a document containing the site's private key is required. This is known as the Certificate Signing Request (CSR) and must be generated digitally at the originating site.
Using the HP SSL for OpenVMS Alpha/IA64/VAX product "SSL Certificate Tool" described in 17.4 - Certificate Management a CSR can easily be generated using it's menu-driven interface. The alternative is using a command-line interface tool.
The following instructions provide the basics for generating a CSR at the command-line in the WASD and generally the any OpenSSL environment (including the HP SSL for OpenVMS Alpha/IA64/VAX product).
$ SET DEFAULT HT_ROOT:[LOCAL]
$ OPENSSL == "$HT_ROOT:[SRC.OPENSSL-version.AXP.EXE.APPS]OPENSSL.EXE"
When using the HP SSL for OpenVMS Alpha/IA64/VAX product or other OpenSSL
toolkit the verb may already be available.
$ SHOW SYMBOL OPENSSL
OPENSSL == "$ SSL$EXE:OPENSSL"
$ RANDFILE = "HT_EXE:HTTPD_SSL.EXE"
HT_ROOT:[SRC.OPENSSL-version.WASD]TEMPLATE.CNF
$ OPENSSL GENRSA -DES3 -OUT SERVER.KEY 1024 Generating RSA private key, 1024 bit long modulus .....++++++ ......++++++ e is 65537 (0x10001) Enter PEM pass phrase: Verifying password - Enter PEM pass phrase:
$ OPENSSL REQ -NEW -KEY SERVER.KEY -OUT SERVER.CSR -CONFIG - HT_ROOT:[SRC.OPENSSL-0_9_6B.WASD]TEMPLATE.CNF Using configuration from template.cnf 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) [AU]:AU State or Province Name (full name) [Some-State]:South Australia Locality Name (eg, city) []:Adelaide Organization Name (eg, company) [Internet Widgits Pty Ltd]:Example Organizational Unit Name (eg, section) []:WASD Common Name (eg, YOUR name) []:klaatu.local.net Email Address []:Mark.Daniel@wasd.vsm.com.au Please enter the following 'extra' attributes to be sent with your certificate request A challenge password []: An optional company name []:
SERVER.CSR;1 2 14-MAR-2002 04:38:26.15 SERVER.KEY;1 2 14-MAR-2002 04:31:38.76
Keep the SERVER.KEY file secure. You'll need it when you receive the certificate back from the CA.
The SERVER.CSR is what you send to the CA (usually by mail or Web
form). It looks something like the following
$ TYPE SERVER.CSR
-----BEGIN CERTIFICATE REQUEST-----
MIIBPTCB6AIBADCBhDELMAkGA1UEBhMCWkExFTATBgNVBAgTDFdlc3Rlcm4gQ2Fw
ZTESMBAGA1UEBxMJQ2FwZSBUb3duMRQwEgYDVQQKEwtPcHBvcnR1bml0aTEYMBYG
A1UECxMPT25saW5lIFNlcnZpY2VzMRowGAYDVQQDExF3d3cuZm9yd2FyZC5jby56
YTBaMA0GCSqGSIb3DQEBAQUAA0kAMEYCQQDT5oxxeBWu5WLHD/G4BJ+PobiC9d7S
6pDvAjuyC+dPAnL0d91tXdm2j190D1kgDoSp5ZyGSgwJh2V7diuuPlHDAgEDoAAw
DQYJKoZIhvcNAQEEBQADQQBf8ZHIu4H8ik2vZQngXh8v+iGnAXD1AvUjuDPCWzFu
pReiq7UR8Z0wiJBeaqiuvTDnTFMz6oCq6htdH7/tvKhh
-----END CERTIFICATE REQUEST-----
You can see the details of this file using
$ OPENSSL RSA -NOOUT -TEXT -IN SERVER.CSR
Once the signed certificate has been issued by the Certificate Authority it can be placed directly into the server configuration directory, usually HT_ROOT:[LOCAL], and configured for use from there. Using the certificate direct from the CA requires that the private key password be given to the server each time (17.3.4 - SSL Private key). It is possible to embed the password into the certificate key so that this is not required.
Remember to keep original files secure, only work on copies!
$ OPENSSL == "$HT_ROOT:[SRC.OPENSSL-version.AXP.EXE.APPS]OPENSSL.EXE"
When using the HP SSL for OpenVMS Alpha/IA64/VAX product or other OpenSSL
toolkit the verb may already be available.
$ SHOW SYMBOL OPENSSL
OPENSSL == "$ SSL$EXE:OPENSSL"
$ SET DEFAULT HT_ROOT:[LOCAL]
$ OPENSSL rsa -in SERVER.KEY -out WORK.PEM
$ COPY CERTIFICATE.PEM,WORK.PEM CERTIFICATE.PEM;0
$ DELETE WORK.PEM;*
CGI variables specific to SSL transactions optionally may be enabled using HTTPD$MAP mapping rules. See 13.4.5 - SET Rule in 13 - Mapping Rules. The may be done on a specific per-path or general CGI basis. Two variations are available, one reflecting Purveyor Secure Web Server style variables, the other the Apache mod_ssl style. In the following examples, due to length of particular items, some in this example are displayed wrapped. Also, where some ASN.1 records are duplicated (as in SSL_CLIENT_S_DN), some variables will contain newline characters (0x10) between those elements (e.g. SSL_CLIENT_S_DN_OU). The line breaks in the examples do not necesarily reflect those characters.
set /path/* SSLCGI=purveyor
WWW_SECURITY_STATUS == "SSL"
WWW_SSL_CIPHER == "RC4-MD5"
WWW_SSL_CIPHER_KEYSIZE == "128"
WWW_SSL_CLIENT_AUTHENTICATED == "TRUE"
WWW_SSL_CLIENT_CA == "/O=VeriSign, Inc./OU=VeriSign Trust Network
/OU=www.verisign.com/repository/RPA Incorp. By Ref.,LIAB.LTD(c)98
/CN=VeriSign Class 1 CA Individual Subscriber-Persona Not Validated"
WWW_SSL_CLIENT_DN == "/O=VeriSign, Inc./OU=VeriSign Trust Network
/OU=www.verisign.com/repository/RPA Incorp. by Ref.,LIAB.LTD(c)98
/OU=Persona Not Validated/OU=Digital ID Class 1 - Netscape
/CN=Mark Daniel/Email=mark.daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_CA == "/C=AU/ST=SA/L=Adelaide/O=WASD HTTPd CA Cert
/OU=OpenSSL 0.9.6 Testing Only/CN=WASD VMS Hypertext Services
/Email=Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_DN == "/C=AU/ST=SA/L=Adelaide/O=WASD HTTPd Server Cert
/OU=OpenSSL 0.9.6 Testing Only/CN=WASD VMS Hypertext Services
/Email=Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_VERSION == "SSLv3"
Note that this example also shows SSL_CLIENT_... variables. These will only be present if the request is X.509 certificate authenticated.
set /path/* SSLCGI=apache_mod_ssl
WWW_SSL_CIPHER == "RC4-MD5"
WWW_SSL_CIPHER_ALGKEYSIZE == "128"
WWW_SSL_CIPHER_USEKEYSIZE == "128"
WWW_SSL_PROTOCOL == "SSLv3"
WWW_SSL_SERVER_A_KEY == "rsaEncryption"
WWW_SSL_SERVER_A_SIG == "md5WithRSAEncryption"
WWW_SSL_SERVER_I_DN == "/C=AU/ST=SA/L=Adelaide/O=WASD HTTPd CA Cert
/OU=OpenSSL 0.9.6 Testing Only/CN=WASD VMS Hypertext Services
/Email=Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_I_DN_C == "AU"
WWW_SSL_SERVER_I_DN_CN == "WASD VMS Hypertext Services"
WWW_SSL_SERVER_I_DN_EMAIL == "Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_I_DN_L == "Adelaide"
WWW_SSL_SERVER_I_DN_O == "WASD HTTPd CA Cert"
WWW_SSL_SERVER_I_DN_OU == "OpenSSL 0.9.6 Testing Only"
WWW_SSL_SERVER_I_DN_ST == "SA"
WWW_SSL_SERVER_M_SERIAL == "01"
WWW_SSL_SERVER_M_VERSION == "3"
WWW_SSL_SERVER_S_DN == "/C=AU/ST=SA/L=Adelaide/O=WASD HTTPd Server Cert
/OU=OpenSSL 0.9.6 Testing Only/CN=WASD VMS Hypertext Services
/Email=Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_S_DN_C == "AU"
WWW_SSL_SERVER_S_DN_CN == "WASD VMS Hypertext Services"
WWW_SSL_SERVER_S_DN_EMAIL == "Mark.Daniel@wasd.vsm.com.au"
WWW_SSL_SERVER_S_DN_L == "Adelaide"
WWW_SSL_SERVER_S_DN_O == "WASD HTTPd Server Cert"
WWW_SSL_SERVER_S_DN_OU == "OpenSSL 0.9.6 Testing Only"
WWW_SSL_SERVER_S_DN_ST == "SA"
WWW_SSL_SERVER_V_END == "Sep 25 00:03:30 2005 GMT"
WWW_SSL_SERVER_V_START == "Sep 26 00:03:30 2000 GMT"
WWW_SSL_SESSION_ID == "344d1b01aa0636cb809eacf270279005f56cd5ebe1154569df810e56003ac70f"
WWW_SSL_VERSION_INTERFACE == "HTTPd-WASD/7.2.0 OpenVMS/AXP SSL"
WWW_SSL_VERSION_LIBRARY == "OpenSSL 0.9.6 24 Sep 2000"
The Apache mod_ssl client certificate details described in
17.3.11 - X.509 Authorization CGI Variables above are not shown in the above example but
would be included if the request was X.509 authenticated.
17.6 - SSL References
The following provide a starting-point for investigating SSL and OpenSSL further (verified available at time of publication).