doc: clarify getAuthTag with authTagLength

tniessen · danielleadams · commit 7f9bf2124139 · 2022-01-31T22:52:54.000-05:00
Refs: #40272 Refs: #20235 PR-URL: #40713 Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: Filip Skokan <panva.ip@gmail.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
diff --git a/doc/api/crypto.md b/doc/api/crypto.md
@@ -551,6 +551,9 @@ added: v1.0.0
 The `cipher.getAuthTag()` method should only be called after encryption has
 been completed using the [`cipher.final()`][] method.
 
+If the `authTagLength` option was set during the `cipher` instance's creation,
+this function will return exactly `authTagLength` bytes.
+
 ### `cipher.setAAD(buffer[, options])`
 
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