Update ChaCha20-Poly1305 documentation
Correctly describe the maximum IV length.
@@ -479,7 +479,9 @@ The following I<ctrl>s are supported for the ChaCha20-Poly1305 AEAD algorithm.
Sets the nonce length. This call can only be made before specifying the nonce.
If not called a default nonce length of 12 (i.e. 96 bits) is used. The maximum
-nonce length is 16 (B<CHACHA_CTR_SIZE>, i.e. 128-bits).
+nonce length is 12 bytes (i.e. 96-bits). If a nonce of less than 12 bytes is set
+then the nonce is automatically padded with leading 0 bytes to make it 12 bytes
+in length.
=item EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, taglen, tag)
