BZ-1730609: Clarify changes for 4.1

modules/identity-provider-about-request-header.adoc

@@ -20,13 +20,13 @@ requests for OAuth tokens to the proxy endpoint that proxies to
 
 To redirect unauthenticated requests from clients expecting browser-based login flows:
 
-1. Set the `provider.loginURL` parameter to the authenticating proxy URL that
+* Set the `provider.loginURL` parameter to the authenticating proxy URL that
 will authenticate interactive clients and then proxy the request to
 `https://_<namespace_route>_/oauth/authorize`.
 
 To redirect unauthenticated requests from clients expecting `WWW-Authenticate` challenges:
 
-1. Set the `provider.challengeURL` parameter to the authenticating proxy URL that
+* Set the `provider.challengeURL` parameter to the authenticating proxy URL that
 will authenticate clients expecting `WWW-Authenticate` challenges and then proxy
 the request to `https://_<namespace_route>_/oauth/authorize`.
 
@@ -35,19 +35,15 @@ the following tokens in the query portion of the URL:
 
 * `${url}` is replaced with the current URL, escaped to be safe in a query parameter.
 +
-For example: `https://www.example.com/sso-login?then=${url}`
+For example: [x-]`https://www.example.com/sso-login?then=${url}`
 
 * `${query}` is replaced with the current query string, unescaped.
 +
-For example: `https://www.example.com/auth-proxy/oauth/authorize?${query}`
+For example: [x-]`https://www.example.com/auth-proxy/oauth/authorize?${query}`
 
-[WARNING]
+[IMPORTANT]
 ====
-If you expect unauthenticated requests to reach the OAuth server, a `clientCA`
-parameter MUST be set for this identity provider, so that incoming requests
-are checked for a valid client certificate before the request's headers are
-checked for a user name. Otherwise, any direct request to the OAuth server can
-impersonate any identity from this provider, merely by setting a request header.
+As of {product-title} 4.1, your proxy must support mutual TLS.
 ====
 
 [id="sspi-windows_{context}"]

modules/identity-provider-request-header-CR.adoc

@@ -58,10 +58,16 @@ If this attribute is not defined, then `challengeURL` must be used.
 <5> Reference to an {product-title} ConfigMap containing a PEM-encoded
 certificate bundle. Used as a trust anchor to validate the TLS
 certificates presented by the remote server.
++
+[IMPORTANT]
+====
+As of {product-title} 4.1, the `ca` field is required for this identity
+provider. This means that your proxy must support mutual TLS.
+====
 <6> Optional: list of common names (`cn`). If set, a valid client certificate with
 a Common Name (`cn`) in the specified list must be presented before the request headers
 are checked for user names. If empty, any Common Name is allowed. Can only be used in combination
-with `clientCA`.
+with `ca`.
 <7> Header names to check, in order, for the user identity. The first header containing
 a value is used as the identity. Required, case-insensitive.
 <8> Header names to check, in order, for an email address. The first header containing