Consider security issues for this CICS web support task.
CICS can implement HTTP
basic authentication for a connection, where the user must supply an ID and password. You can
use the user ID to control access to individual resources used for application-generated responses
or static responses. If you need to protect information that is passed over the Internet
(including the user IDs and passwords that are used for basic authentication), consider using Secure
Sockets Layer (SSL). For more information, see Security for CICS web support.
If you want to use a z/OS UNIX System
Services file to provide a response, create the file and place it
in an appropriate location in the z/OS UNIX file
system.
When this response is identified by a URIMAP definition
that matches the web client request, CICS retrieves
the file and carries out appropriate code page conversion. Note these
points:
Do not include any HTTP headers or status line information
in the z/OS UNIX file.
CICS generates
the required information when the response is sent. The z/OS UNIX file
provides only the body of the response.
The location of the file is significant if you want
to use path matching, as described later in this task. If you do not
want to use path matching, the location of the file does not need
to have any relationship to the URL of the request.
The CICS region
must have permissions to access z/OS
UNIX, and it must
have permission to access the directory containing the file and the file itself.
If you are implementing access control using the user IDs of web clients, the user IDs must
also have permission to access the directory containing the file, and the file itself.
If you want to use a CICS document template to provide the response, create the document template, following the
instructions in Creating a document.
The document template is defined using a DOCTEMPLATE resource definition. The document
template can be held in a partitioned data set, a CICS program, a file, a temporary storage queue, a transient data
queue, an exit program or a z/OS
UNIX System
Services file.
When this response is identified by a URIMAP definition that matches the web client request,
CICS creates a
document using the template, retrieves the document, and carries out appropriate code page
conversion.
Do not include any HTTP headers or status line information in the document template.
CICS generates
the required information when the response is sent. The document template provides only the body of
the response.
A query string that consists of name and value pairs can be used as a symbol list and
substituted into a document template.
(The query string cannot be used in this way if it has already been used for URIMAP matching,
as part of the PATH attribute in the URIMAP definition.)
To make the client send a query string of the expected format in the URL, send an HTML form
with the GET method for the user to spcify.
Any of the names in the query string can be coded in the document template as a symbol,
and, when the template is used, CICS substitutes each symbol for the value specified in the query string. For
example, if you have obtained a query string that includes a name and value pair
username=Peter, you can use this in your document template by coding
username as a
symbol:
Welcome to the finance system, &username;.
The resulting static
response delivered to the user will read:
Welcome to the finance system, Peter.
Note: Symbols in document templates are
case-sensitive. Specify the name using the same case as in the original query
string.
Any name and value pairs that do not correspond to symbols in the document template are
ignored.
If you are implementing resource level security using the user IDs of web clients, the user IDs
must have permission to access the document template.
See CICS system and resource security for CICS web support. Note that, if the document template is a
z/OS
UNIX System
Services file, the web clients do not need to be given permissions on the file, but only on the
DOCTEMPLATE resource definition.
Identify the media type (type of data content) that is provided by the z/OS
UNIX file or CICS document
template.
Note that when you use a URIMAP definition to send a static response, the use of quality
factors (the "q" parameter) is not supported. Use quality factors to choose among a client list of
acceptable media types or character sets, as specified in Accept headers. To carry out this type of
analysis, you can use an application-generated response instead.
Identify the information that CICS requires for code page conversion of the static response.
If you want to use path matching in the
URIMAP definition, plan your request URLs and arrange the names of
your CICS document templates or the locations of
your z/OS UNIX files to support it.
In
path matching, a wildcard character is used in the path component
of the URIMAP definition, and also in the name of the CICS document
template or z/OS UNIX file that is specified by
the URIMAP definition. The portion of the path that is covered by
the wildcard character is used to select the document template or z/OS UNIX file
to provide the response.
For CICS document templates, the portion
of the path that is covered by the wildcard character is substituted
as the last part of the template name. You can create a collection
of document templates with names that begin in the same way, and access
them using request URLs whose paths begin in the same way, through
a single URIMAP definition.
For z/OS UNIX files,
the portion of the path that is covered by the wildcard character
is substituted as the last part of the file name. You can store a
number of these files in the same directory, and access them using
request URLs with paths that begin in the same way, through a single
URIMAP definition.
Bear in mind that because a URIMAP definition
must specify a type of data content (the MEDIATYPE attribute), a single
URIMAP definition can handle only a group of z/OS UNIX files
that produce the same type of data content.
Decide on the port that is used for the requests,
referring to
For HTTP, the default port number is 80, and, for HTTPS (with
SSL), the default port number is 443. Port numbers that are not the
default for a scheme are specified explicitly in the URL of requests.
If you prefer, you can allow a request to use any port that
is associated with CICS web support.
Use this definition to specify the security measures that you
have selected for the port (such as the use of SSL and basic authentication).
The name of the relevant TCPIPSERVICE definition is specified
in the URIMAP definition for the request. Specifying no TCPIPSERVICE
definition means that requests matched by the URIMAP definition can
use any port for which a TCPIPSERVICE definition exists.
The URIMAP definition can identify either a z/OS UNIX file
or a document template.
Check the error handling procedures for this CICS web
support task.
Check the behavior of the analyzer program associated with the TCPIPSERVICE definition for the
port on which the requests are received. If URIMAP matching fails for a request, the request is
passed on to the analyzer program.
If the port is used only for static responses, the CICS-supplied default analyzer program
DFHWBAAX provides suitable error handling. Otherwise, the choice of analyzer program is likely to
depend on the requirements of user application programs, and you might need to customize it to
provide suitable error handling for static responses. See Analyzer programs.
Ensure that the user-replaceable web error programs that are involved in your architecture
provide appropriate responses to the web client.
