A third-party device acting as an ICAP client can forward HTTP requests and responses to an ICAP server for processing. An appliance acting as an ICAP server receives the file objects from the ICAP client and extracts the objects for analysis. The ICAP service supports ICAP messages in request modification (REQMOD) mode and in response modification (RESPMOD) mode:
In request modification mode, an ICAP client can send the appliance ICAP-encapsulated HTTP requests.
In response modification mode, an ICAP client can send the appliance ICAP-encapsulated HTTP responses.
The ICAP-enabled appliance performs content transformation on the ICAP REQMOD or RESPMOD request sent by the ICAP client and sends back responses with appropriate action to take on the encapsulated HTTP request or response.
REQMOD support and RESPMOD support are enabled by default.
When REQMOD or RESPMOD is disabled for the ICAP service, the Intelligent Virtual Execution - Server appliance sends the ICAP client a 204 response code.
You can enable or disable the REQMOD and the RESPMOD for the ICAP service by using the Intelligent Virtual Execution - Server appliance CLI:
icap-service respmod enable— This command enables the processing of response modification for ICAP data.no icap-service respmod enable— This command disables the processing of response modification for ICAP data.icap-service reqmod enable— This command enables the processing of request modification for ICAP data.no icap-service reqmod enable— This command disables the processing of request modification for ICAP data.
REQMOD now supports uploading up to 5 files in a single submission request. When a user uploads multiple attachments, the ICAP client forwards all files in one combined request to the ICAP server. All attachments are scanned as part of the same request. If any one of these files is found to be malicious, the entire request is blocked. RESPMOD does not support multiple file uploads.
This update is available on all systems running IVX Server build 11.0.0.1020552 (11.0.0-abbot-hotfix) or later. See KB14797 for more details.
hostname # show icap-service stats ICAP Service Statistics: ------------------------ ICAP REQMOD Received : 618 ICAP REQMOD Blocked : 13 ICAP RESPMOD Received : 3256 ICAP RESPMOD Blocked : 1 ICAP File Submissions : 2915
A single upload request can now include up to five files. In this case, the ICAP REQMOD Received stat will increase by 1, while the ICAP File Submissions stat will show the total number of files uploaded (up to five files per request).