2 library(ssl): Secure Socket Layer (SSL) library
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Availability::- use_module(library(ssl)).(can be autoloaded)
Source[det]load_certificate(+Stream, -Certificate)
Loads a certificate from a PEM- or DER-encoded stream, returning a certificate. The fields of the certificate can be inspected using certificate_field(+Certificate, ?Field).

Note that the OpenSSL CA.pl utility creates certificates that have a human readable textual representation in front of the PEM representation. You can use the following to skip to the certificate if you know it is a PEM certificate: 

skip_to_pem_cert(In) :-
      repeat,
      (   peek_char(In, '-')
      ->  !
      ;   skip(In, 0'\n),
          at_end_of_stream(In), !
      ).