untrusted CA certificates that may be used for chain building as well as CRLs that may be used for certificate validation. <i>store</i> may be NULL or point to the trusted certificate store to use for chain verification. <i>indata</i> refers to the signed data if the content is detached from <i>p7</i>. Otherwise <i>indata</i> should be NULL, and then the signed data must be in <i>p7</i>. The content is written to the BIO <i>out</i> unless it is NULL. <i>flags</i> is an optional set of flags, which can be us