tls: remove checkIP options argument

None of the supported options have any effect on X509_check_ip_asc.

(iPAddress is not a typo, it is what RFC 5280 calls subject alternative
names that are IP addresses.)

Refs: openssl/openssl#17536

Author: tniessen

doc/api/crypto.md

@@ -2509,24 +2509,25 @@ or it might contain wildcards (e.g., `*.example.com`). Because host name
 comparisons are case-insensitive, the returned subject name might also differ
 from the given `name` in capitalization.
 
-### `x509.checkIP(ip[, options])`
+### `x509.checkIP(ip)`
 
 <!-- YAML
 added: v15.6.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/41571
+    description: The `options` argument has been removed since it had no effect.
 -->
 
 * `ip` {string}
-* `options` {Object}
-  * `subject` {string} `'always'` or `'never'`. **Default:** `'always'`.
-  * `wildcards` {boolean} **Default:** `true`.
-  * `partialWildcards` {boolean} **Default:** `true`.
-  * `multiLabelWildcards` {boolean} **Default:** `false`.
-  * `singleLabelSubdomains` {boolean} **Default:** `false`.
 * Returns: {string|undefined} Returns `ip` if the certificate matches,
   `undefined` if it does not.
 
 Checks whether the certificate matches the given IP address (IPv4 or IPv6).
 
+Only `iPAddress` subject alternative names are considered, and they must match
+the given `ip` address exactly. The certificate subject is ignored.
+
 ### `x509.checkIssued(otherCert)`
 
 <!-- YAML

lib/internal/crypto/x509.js

@@ -313,6 +313,11 @@ class X509Certificate extends JSTransferable {
 
   checkIP(ip, options) {
     validateString(ip, 'ip');
+    // The options argument is currently undocumented since none of the options
+    // have any effect on the behavior of this function. However, we still parse
+    // the options argument in case OpenSSL adds flags in the future that do
+    // affect the behavior of X509_check_ip. This ensures that no invalid values
+    // are passed as the second argument in the meantime.
     return this[kHandle].checkIP(ip, getFlags(options));
   }