I have a binary file format that is written in BigEndian order. The files are of varying size so I can't use Sequential_IO for this, as I need to read different types.

The problem is, when using Stream_IO, I can't find a way to use BigEndian, and Scalar_Storage_Order also doesn't affect anything. Also, I'm a very fresh beginner at Ada and overall tips and suggestions to the code are very welcome.

share.adb:
with Ada.Text_IO;
with Ada.Streams.Stream_IO; use Ada.Streams.Stream_IO;
with Ada.Streams;           use Ada.Streams;

package body Share is

   procedure Read_Share (Segment_Size : Positive; Required_Shares : Positive)
   is
      --  Ceiling function
      Block_Size : constant Positive :=
        (Segment_Size + (Required_Shares - 1)) / Required_Shares;
      type Block is array (Integer range 0 .. Block_Size) of Byte;

      S               : Stream_Access;
      Share_File      : File_Type;
      My_Share_Header : Share_Header;
   begin
      Open (Share_File, In_File, "../go-tahoe/3");
      S := Stream (Share_File);
      Share_Header'Read (S, My_Share_Header);
      My_Share_Header.Block_Size := Unsigned_32 (Block_Size);
      Display_Share_Content (My_Share_Header);

      Close (Share_File);
      --  Read_Blocks (My_Share_Header, Share_File);

      --  Now My_Share contains the values read from the binary file
   end Read_Share;

   procedure Display_Share_Content (My_Share_Header : Share_Header) is
   begin
      Ada.Text_IO.Put_Line
        ("Share version: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Version));
      Ada.Text_IO.Put_Line
        ("Share Data Length: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Data_Length));
      Ada.Text_IO.Put_Line
        ("Lease Number: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Lease_number));
      Ada.Text_IO.Put_Line
        ("Share version: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Version));
      Ada.Text_IO.Put_Line
        ("Block Size: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Block_Size));
      Ada.Text_IO.Put_Line
        ("Data Size: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Data_Size));
      Ada.Text_IO.Put_Line
        ("Data offset: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Data_Offset));
      Ada.Text_IO.Put_Line
        ("Plaintext hash tree offset: " &
         Interfaces.Unsigned_32'Image
           (My_Share_Header.Plaintext_Hash_Tree_Offset));
      Ada.Text_IO.Put_Line
        ("Crypttext hash tree offset: " &
         Interfaces.Unsigned_32'Image
           (My_Share_Header.Crypttext_Hash_Tree_Offset));
      Ada.Text_IO.Put_Line
        ("Block hashes offset: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Block_Hashes_Offset));
      Ada.Text_IO.Put_Line
        ("Share hashes offset: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.Share_Hashes_Offset));
      Ada.Text_IO.Put_Line
        ("URI Extension Length and URI Extension block offset: " &
         Interfaces.Unsigned_32'Image (My_Share_Header.URI_Extension_Offset));
   end Display_Share_Content;

   procedure Read_Blocks
     (My_Share_Header : Share_Header; Share_File : File_Type)
   is
      Total_Blocks : Interfaces.Unsigned_32 := My_Share_Header.Data_Size;
   begin
      Ada.Text_IO.Put ("");

   end Read_Blocks;
end Share;

share.ads:
with Interfaces; use Interfaces;
with System;     use System;
with Ada.Streams.Stream_IO;

package Share is

   type Byte is new Interfaces.Unsigned_8;
   type Kilobyte is array (Integer range 0 .. 1_023) of Byte;
   type Kilobyte_array is array (Integer range <>) of Kilobyte;

   type Share_Header is record
      Version                    : Unsigned_32;
      Data_Length                : Unsigned_32;
      Lease_number               : Unsigned_32;
      Version_Junk               : Unsigned_32;
      --  unused as it can be calculated from the URI
      Block_Size                 : Unsigned_32;
      Data_Size                  : Unsigned_32;
      Data_Offset                : Unsigned_32;
      Plaintext_Hash_Tree_Offset : Unsigned_32;
      Crypttext_Hash_Tree_Offset : Unsigned_32;
      Block_Hashes_Offset        : Unsigned_32;
      Share_Hashes_Offset        : Unsigned_32;
      URI_Extension_Offset       : Unsigned_32;
   end record;

   for Share_Header use record
      Version at 0 range 0 .. 32;
      --  Data_Length                : Unsigned_32;
      --  Lease_number               : Unsigned_32;
      --  Version_Junk               : Unsigned_32;
      --  --  unused as it can be calculated from the URI
      --  Block_Size                 : Unsigned_32;
      --  Data_Size                  : Unsigned_32;
      --  Data_Offset                : Unsigned_32;
      --  Plaintext_Hash_Tree_Offset : Unsigned_32;
      --  Crypttext_Hash_Tree_Offset : Unsigned_32;
      --  Block_Hashes_Offset        : Unsigned_32;
      --  Share_Hashes_Offset        : Unsigned_32;
      --  URI_Extension_Offset       : Unsigned_32;
   end record;

   for Share_Header'Bit_Order use High_Order_First;
   for Share_Header'Scalar_Storage_Order use High_Order_First;

   procedure Read_Share (Segment_Size : Positive; Required_Shares : Positive);
   procedure Display_Share_Content (My_Share_Header : Share_Header);
   procedure Read_Blocks
     (My_Share_Header : Share_Header;
      Share_File      : Ada.Streams.Stream_IO.File_Type);
end Share;

Tried defining the component clauses to not much success, different bit orders, modifying the Stream_IO storage arrays.