7.7. Setting up Resumable CRL Downloads

Certificate System provides option for interrupted CRL downloads to be resumed smoothly. This is done by publishing the CRLs as a plain file over HTTP. This method of downloading CRLs gives flexibility in retrieving CRLs and lowers overall network congestion.

7.7.1. Retrieving CRLs Using wget

Because CRLs can be published as a text file over HTTP, they can be manually retrieved from the CA using a tool such as wget. The wget command can be used to retrieve any published CRL. For example, to retrieve a full CRL which is newer than the previous full CRL:
[root@server ~]# wget --no-check-certificate -d https://server.example.com:8443/ca/ee/ca/crl/MasterCRL.bin
The relevant parameters for wget are summarized in Table 7.4, “wget Options to Use for Retrieving CRLs”.

Table 7.4. wget Options to Use for Retrieving CRLs

Argument Description
no argument Retrieves the full CRL.
-N Retrieves the CRL that is newer than the local copy (delta CRL).
-c Retrieves a partially-downloaded file.
--no-check-certificate Skips TLS for the connection, so it is not necessary to configure TLS between the host and client.
-d Prints debug information.