curtail ASN1 memory leaks

this was two different leaks rolled into one, which i will explain below.
i also have to note the test still leaks *some* objects, but i don't have
the time to do full analysis on that

modules used to diagnose the leaks:
Net::Prometheus, Devel::Gladiator, Devel::FindRef, Devel::Cycle

openxpki#1 is the globals in the parser holding on to things

normally deciding when to clean these up could be a little tricky, but the
parsing appears to be contained entirely within the _new method, so we can
declare them local and have perl reset them at the end of scope

optimally Convert::ASN1 would take care of this so they're deleted after
they're needed; as well as instanced per object or creation of new parsers
guarded while one is currently active

openxpki#2 is PKCS10 creating the object, running ->find on it, which returns a
*shallow* copy with a reference to a config hash in the original object,
then puts said shallow copy into the config hash of the original object,
which creates a cycle

at first i thought weaken would be the more appropriate option here, but
that simply crashed on trying to parse certain certs, so a deep clone is
used and seems to fix the issue

lib/Crypt/PKCS10.pm

@@ -21,6 +21,7 @@ use Convert::ASN1( qw/:tag :const/ );
 use Encode ();
 use MIME::Base64;
 use Scalar::Util ();
+use Clone 'clone';
 
 our $VERSION = '2.005';
 
@@ -744,6 +745,7 @@ sub _new {
 
     $self->{_bmpenc} = Encode::find_encoding('UCS2-BE');
 
+    local ( $Convert::ASN1::parser::yyval, @Convert::ASN1::parser::yyvs );
     my $asn = Convert::ASN1->new;
     $self->{_asn} = $asn;
     $asn->prepare($schema) or die( "Internal error in " . __PACKAGE__ . ": " . $asn->error );
@@ -1162,7 +1164,7 @@ sub _init {
     my $self = shift;
     my( $node, $optional ) = @_;
 
-    my $parsed = $self->{_asn}->find($node);
+    my $parsed = clone $self->{_asn}->find($node);
 
     unless( defined $parsed || $optional ) {
 	croak( "Missing node $node in ASN.1" );

t/02_base.t

@@ -30,7 +30,7 @@ my @dirpath = (File::Spec->splitpath( $0 ))[0,1];
 
 my $decoded;
 
-plan  tests => 12;
+plan  tests => 13;
 
 # Basic functions test requires RSA
 
@@ -820,6 +820,18 @@ subtest 'API v0' => sub {
     # More API v0 tests needed
 };
 
+if ( not eval { require Net::Prometheus } ) {
+    diag "Net::Prometheus not installed, skipping leak test";
+    ok 1;
+}
+else {    # there are some leaks left, but i ran out of time on those
+    $decoded = undef;
+    is(
+        ( Net::Prometheus::PerlCollector::count_heap(2) )[3]
+          ->{"Convert::ASN1::parser"},
+        undef,
+        "no uncontrolled parser objects leak"
+    );
+}
 
 1;
-

t/05_csr_parse_leak.t

@@ -0,0 +1,51 @@
+#!/usr/bin/env perl
+use strict;
+use warnings;
+
+use Test::More;
+use Crypt::PKCS10;
+
+run();
+
+sub run {
+    Crypt::PKCS10->setAPIversion(1);
+
+    my $string = "-----BEGIN NEW CERTIFICATE REQUEST-----
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
+-----END NEW CERTIFICATE REQUEST-----";
+
+    my $pkcs10 = Crypt::PKCS10->new($string);
+    ok( $pkcs10, "got a parse result" );
+    is( Crypt::PKCS10->error, undef, "no errors parsing the CSR" );
+
+    $pkcs10->commonName;
+    $pkcs10->countryName;
+    $pkcs10->stateOrProvinceName;
+    $pkcs10->organizationName;
+    $pkcs10->emailAddress;
+    $pkcs10->extensionPresent('subjectAltName');
+    $pkcs10->extensionValue('subjectAltName');
+    $pkcs10->commonName;
+    $pkcs10->csrRequest(1);
+    $pkcs10 = undef;
+
+    if ( not eval { require Net::Prometheus } ) {
+        diag "Net::Prometheus not installed, skipping leak test";
+        ok 1;
+    }
+    else {    # there are some leaks left, but i ran out of time on those
+        note $_ for grep /UDAG|Convert::ASN1/,    #
+          split /\n/,
+          Net::Prometheus->new->render( { perl_collector_detail => 2 } );
+        is(
+            ( Net::Prometheus::PerlCollector::count_heap(2) )[3]    #
+              {"Convert::ASN1::parser"},
+            undef,
+            "no leak"
+        );
+    }
+
+    done_testing;
+
+    return;
+}