it has some additional parameters described next,
and on success it returns the verfied content as a memory BIO.
The optional I<extra> parameter may be used to provide untrusted CA
-certificates that may be helpful for chain building in certificate valiation.
+certificates that may be helpful for chain building in certificate validation.
This list of certificates must not contain duplicates.
The optional I<crls> parameter may be used to provide extra CRLs.
Also the list of CRLs must not contain duplicates.