refactor offsets

peczenyj · Dec 12, 2023 · 7fafe0e · 7fafe0e
1 parent 6a4ca72
commit 7fafe0e
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Showing 5 changed files with 41 additions and 44 deletions.
diff --git a/lib/GDPR/IAB/TCFv2.pm b/lib/GDPR/IAB/TCFv2.pm
@@ -120,15 +120,6 @@ sub Parse {
 
     croak 'invalid vendor list version' if $self->vendor_list_version == 0;
 
-    # TODO parse special feature opt in
-
-    #_parse_bitfield()
-
-    # TODO parse purpose section
-    # TODO parse purpose consent
-
-    # TODO parse purpose legitimate interest
-
     # parse vendor section
     # parse vendor consent
 
@@ -495,16 +486,18 @@ sub _parse_vendor_legitimate_interests {
 sub _parse_publisher_restrictions {
     my ( $self, $pub_restrict_offset ) = @_;
 
-    my ($publisher_restrictions, $next_offset) = GDPR::IAB::TCFv2::PublisherRestrictions->Parse(
-        data => $self->{data},
-        offset => $pub_restrict_offset,
-        max_id =>ASSUMED_MAX_VENDOR_ID,
+    my $data = substr($self->{data}, $pub_restrict_offset, ASSUMED_MAX_VENDOR_ID);
+
+    my ($publisher_restrictions, $relative_next_offset) = GDPR::IAB::TCFv2::PublisherRestrictions->Parse(
+        data    => $data,
+        data_size => length($self->{data}),
+        max_id  => ASSUMED_MAX_VENDOR_ID,
         options => $self->{options},
     );
 
     $self->{publisher_restrictions} = $publisher_restrictions;
 
-    return $next_offset;
+    return $pub_restrict_offset + $relative_next_offset;
 }
 
 sub _get_core_tc_string {
@@ -550,30 +543,33 @@ sub _is_vendor_consent_range_encoding {
 }
 
 sub _parse_range_section {
-    my ( $self, $max_id, $offset ) = @_;
+    my ( $self, $max_id, $range_section_start_offset ) = @_;
+
+    my $data = substr($self->{data}, $range_section_start_offset, $max_id);
 
     my ( $range_section, $next_offset ) =
       GDPR::IAB::TCFv2::RangeSection->Parse(
-        data    => $self->{data},
-        offset  => $offset,
+        data    => $data,
+        data_size => length($self->{data}),
         max_id  => $max_id,
         options => $self->{options},
       );
 
-    return ( $range_section, $next_offset );
+    return wantarray  ? ( $range_section, $range_section_start_offset +$next_offset ) : $range_section;
 }
 
 sub _parse_bitfield {
-    my ( $self, $max_id, $offset ) = @_;
+    my ( $self, $max_id, $bitfield_start_offset ) = @_;
+
+    my $data = substr($self->{data}, $bitfield_start_offset, $max_id);
 
     my ( $bitfield, $next_offset ) = GDPR::IAB::TCFv2::BitField->Parse(
-        data    => $self->{data},
-        offset  => $offset,
+        data    => $data,
         max_id  => $max_id,
         options => $self->{options},
     );
 
-    return ( $bitfield, $next_offset );
+    return wantarray ? ( $bitfield, $bitfield_start_offset + $next_offset ) : $bitfield;
 }
 
 sub looksLikeIsConsentVersion2 {

diff --git a/lib/GDPR/IAB/TCFv2/BitField.pm b/lib/GDPR/IAB/TCFv2/BitField.pm
@@ -10,16 +10,15 @@ use Carp                       qw<croak>;
 sub Parse {
     my ( $klass, %args ) = @_;
 
-    croak "missing 'data'"   unless defined $args{data};
-    croak "missing 'offset'" unless defined $args{offset};
+    croak "missing 'data'" unless defined $args{data};
     croak "missing 'max_id'"
       unless defined $args{max_id};
 
     croak "missing 'options'"      unless defined $args{options};
     croak "missing 'options.json'" unless defined $args{options}->{json};
 
     my $data    = $args{data};
-    my $offset  = $args{offset};
+    my $offset  = $args{offset} || 0;
     my $max_id  = $args{max_id};
     my $options = $args{options};
 

diff --git a/lib/GDPR/IAB/TCFv2/PublisherRestrictions.pm b/lib/GDPR/IAB/TCFv2/PublisherRestrictions.pm
@@ -16,18 +16,19 @@ use GDPR::IAB::TCFv2::BitUtils qw<is_set
 sub Parse {
     my ( $klass, %args ) = @_;
 
-    croak "missing 'data'"   unless defined $args{data};
-    croak "missing 'offset'" unless defined $args{offset};
+    croak "missing 'data'"      unless defined $args{data};
+    croak "missing 'data_size'" unless defined $args{data_size};
     croak "missing 'max_id'"
       unless defined $args{max_id};
 
     croak "missing 'options'"      unless defined $args{options};
     croak "missing 'options.json'" unless defined $args{options}->{json};
 
-    my $data    = $args{data};
-    my $offset  = $args{offset};
-    my $max_id  = $args{max_id};
-    my $options = $args{options};
+    my $data      = $args{data};
+    my $data_size = $args{data_size};
+    my $offset    = $args{offset} || 0;
+    my $max_id    = $args{max_id};
+    my $options   = $args{options};
 
     my ( $num_restrictions, $next_offset ) = get_uint12( $data, $offset );
 
@@ -42,10 +43,11 @@ sub Parse {
 
         ( $vendor_restrictions, $next_offset ) =
           GDPR::IAB::TCFv2::RangeSection->Parse(
-            data    => $data,
-            offset  => $next_offset,
-            max_id  => $max_id,
-            options => $options,
+            data      => $data,
+            data_size => $data_size,
+            offset    => $next_offset,
+            max_id    => $max_id,
+            options   => $options,
           );
 
         $restrictions{$purpose_id} ||= {};
@@ -111,7 +113,7 @@ GDPR::IAB::TCFv2::PublisherRestrictions - Transparency & Consent String version
         max_id =>ASSUMED_MAX_VENDOR_ID,
         options => $self->{options},
     );
-    
+
     die "there is publisher restriction on purpose id 1, type 0 on vendor 284"
         if $range->contains(1, 0, 284);
 

diff --git a/lib/GDPR/IAB/TCFv2/RangeSection.pm b/lib/GDPR/IAB/TCFv2/RangeSection.pm
@@ -10,22 +10,22 @@ use Carp                       qw<croak>;
 sub Parse {
     my ( $klass, %args ) = @_;
 
-    croak "missing 'data'"   unless defined $args{data};
-    croak "missing 'offset'" unless defined $args{offset};
+    croak "missing 'data'"      unless defined $args{data};
+    croak "missing 'data_size'" unless defined $args{data_size};
     croak "missing 'max_id'"
       unless defined $args{max_id};
 
     croak "missing 'options'"      unless defined $args{options};
     croak "missing 'options.json'" unless defined $args{options}->{json};
 
-    my $data    = $args{data};
-    my $offset  = $args{offset};
+    my $data      = $args{data};
+    my $data_size = $args{data_size};
+
+    my $offset  = $args{offset} || 0;
     my $max_id  = $args{max_id};
     my $options = $args{options};
 
-    my $data_size = length($data);
-
-    croak
+    Carp::confess
       "a BitField for vendor consent strings using RangeSections require at least 31 bytes. Got $data_size"
       if $data_size < 31;
 

diff --git a/t/01-parse.t b/t/01-parse.t
@@ -427,7 +427,7 @@ subtest "invalid tcf consent string candidates" => sub {
         GDPR::IAB::TCFv2->Parse(
             'COvcSpYOvcSpYC9AAAENAPCAAAAAAAAAAAAAAFQBgAAgABAACAAEAAQAAgAA')
     }
-    qr/index out of bounds on offset 360/,
+    qr/index out of bounds on offset 0: can't read 12, only has: 10/,
       'this test uses a crafted consent uses range section, declares 10 vendors, 6 exceptions and legitimate interest without require';