Opening and checking a Pem file in SWI-Prolog

Question

How to open a Pem file for verification a) That the dates "Not Before" and "Not After" are OK and b) What is the certificate chain in the pem file for the route certification authority?

I tried:

:-use_module(library(http/http_client)).

url('http://fm4dd.com/openssl/source/PEM/certs/512b-rsa-example-cert.pem').

url_data(Url,D):-
 http_get(Url,D,[to(string)]).

url_data1(Url,Certificate):-
 http_get(Url,D,[to(stream(Stream))]),
 load_certificate(Stream, Certificate),
 close(Stream).

url_data/1works in that it returns the pem file as a string. But url_data1/1does not work. It is intended to return each certificate (s) to the list of terms.

* Update *

I have:

url_data1(Url,Certs):-
 http_open(Url,Stream,[]),
 all_certs(Stream,Certs),
 forall(member(C,Certs),my_validate(C)),
 close(Stream).

all_certs(Stream,[C1|Certs]):-
 catch(load_certificate(Stream,C1),_,fail),
 all_certs(Stream,Certs),!.
all_certs(_Stream,[]).

my_validate(C):-
 memberchk(to_be_signed(Signed),C),
 memberchk(key(Key),C),
 memberchk(signature(Signature),C),
 memberchk(signature_algorithm(A),C),
 algo_code(A,Code),
 rsa_verify(Key,Signed,Signature,[type(Code)]).

algo_code('RSA-SHA256',sha256).
algo_code('RSA-SHA1',sha1).

That does not work. What are the right arguments?

Answer 1

You can use http_open/3in combination with load_certificate/2:

? - url (Url),
   http_open (Url, Stream, []),
   load_certificate (Stream, Certificate),
   maplist(portray_clause, Certificate).

:

version(0).
notbefore(1345613214).
notafter(1503293214).
serial('0DFA').
subject(['C'='JP', 'ST'='Tokyo', 'O'='Frank4DD', 'CN'='www.example.com']).
hash("071CB94F0CC8514D024124708EE8B2687BD7D9D5").
signature("14B64CBB817933E671A4DA516FCB081D8D60ECBC18C7734759B1F22048BB61FAFC4DAD898DD121EBD5D8E5BAD6A636FD745083B60FC71DDF7DE52E817F45E09FE23E79EED73031C72072D9582E2AFE125A3445A119087C89475F4A95BE23214A5372DA2A052F2EC970F65BFAFDDFB431B2C14A9C062543A1E6B41E7F869B1640").
signature_algorithm('RSA-SHA1').
etc.

issuer_name/1 . load_certificate/2, . N/a.

, - ( HTTPS), ssl_peer_certificate/2 ssl_peer_certificate_chain/2 .

, signature/1, to_be_signed/1 , .

library(crypto) .