b5b9efe Allow an empty cookie in dogtag-ipa-ca-renew-agent-submit

Authored and Committed by rcritten a month ago
    Allow an empty cookie in dogtag-ipa-ca-renew-agent-submit
    
    A "cookie" is used with certmonger to track the state of a
    request across multiple requests to a CA (in ca-cookie). This
    is used with the certmonger POLL operation to submit a request
    to the CA for the status of a certificate request. This, along
    with the profile, are passed to the certmonger CA helper
    scripts via environment variables when a request is made. It is
    cleared from the certmonger request once the certificate is
    issued.
    
    This CA helper can do a number of things:
    
    - SUBMIT new certicate requests (including the CA)
    - POLL for status of an existing certificate request
    - For non renewal masters, POLL to see if an updated cert is in
      LDAP
    
    A POLL operation requires a cookie so that the state about the
    request can be passed to the CA. For the case of retrieving an
    updated cert from LDAP there is no state to maintain. It just
    checks LDAP and returns either a cert or WAIT_WITH_DELAY if one
    is not yet available.
    
    There are two kinds of cookies in operation here:
    1. The CERTMONGER_CA_COOKIE environment variable passed via
       certmonger to this helper which is a JSON object.
    2. The cookie value within the JSON object which contains the
       URL to be passed to dogtag.
    
    For the purposes of clarity "cookie" here is the value within
    the JSON.
    
    The CERTMONGER_CA_COOKIE is deconstructed and reconstructed as
    the request is processed, doing double duty. It initially comes
    in as a JSON dict object with two keys: profile and cookie.
    In call_handler the CERTMONGER_CA_COOKIE is decomposed into a
    python object and the profile compared to the requested profile
    (and request rejected if they don't match) and the cookie key
    overrides the CERTMONGER_CA_COOKIE environment variable. This is
    then reversed at the end of the request when it again becomes a
    JSON object containing the profile and cookie.
    
    This script was previously enforcing that a cookie be available on
    all POLL requests, whether it is actually required or not. This
    patch relaxes that requirement.
    
    The first request of a non-renewal master for an updated certicate
    from LDAP is a SUBMIT operation. This is significant because it
    doesn't require a cookie: there is no state on a new request. If
    there is no updated cert in LDAP then the tracking request goes
    into the CA_WORKING state and certmonger will wait 8 hours (as
    returned by this script) and try again.
    
    Subsequent requests are done using POLL. This required a cookie
    so all such requests would fail with the ca-error
    Invalid cookie: u'' as it was empty (because there is no state).
    
    There is no need to fail early on a missing cookie. Enforcement
    will be done later if needed (and it isn't always needed). So
    if CERTMONGER_CA_COOKIE is an empty string then generate a new
    CERTMONGER_CA_COOKIE containing the requested profile and an empty
    cookie. It still will fail if certmonger doesn't set a cookie at
    all.
    
    An example of a cookie when retrieving a new RA Agent certificate
    is:
    
    {"profile": "caServerCert", "cookie": "state=retrieve&requestId=20"}
    
    This will result in this request to the CA:
    [09/Jan/2020:14:29:54 -0500] "GET
    /ca/ee/ca/displayCertFromRequest?requestId=20&importCert=true&xml=true
    HTTP/1.1" 200 9857
    
    For a renewal, the reconstructed cookie will consist of:
    
    {"profile": "caServerCert", "cookie": ""}
    
    https://pagure.io/freeipa/issue/8164
    
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>