Use Stream extension to ensure read operations return the requested number of bytes (unless EOF arrives first).

Aaru.Helpers.csproj

@@ -47,6 +47,7 @@
         <Compile Include="BigEndianBitConverter.cs" />
         <Compile Include="BitEndian.cs" />
         <Compile Include="DateHandlers.cs" />
+        <Compile Include="Extensions.cs"/>
         <Compile Include="Marshal.cs" />
         <Compile Include="MarshallingPropertiesAttribute.cs" />
         <Compile Include="PrintHex.cs" />

Extensions.cs

@@ -0,0 +1,72 @@
+// /***************************************************************************
+// Aaru Data Preservation Suite
+// ----------------------------------------------------------------------------
+//
+// Filename       : Extensions.cs
+// Author(s)      : Natalia Portillo <claunia@claunia.com>
+//
+// Component      : Helpers.
+//
+// --[ Description ] ----------------------------------------------------------
+//
+//     Provides class extensions.
+//
+// --[ License ] --------------------------------------------------------------
+//
+//     This library is free software; you can redistribute it and/or modify
+//     it under the terms of the GNU Lesser General Public License as
+//     published by the Free Software Foundation; either version 2.1 of the
+//     License, or (at your option) any later version.
+//
+//     This library is distributed in the hope that it will be useful, but
+//     WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+//     Lesser General Public License for more details.
+//
+//     You should have received a copy of the GNU Lesser General Public
+//     License along with this library; if not, see <http://www.gnu.org/licenses/>.
+//
+// ----------------------------------------------------------------------------
+// Copyright © 2011-2022 Natalia Portillo
+// ****************************************************************************/
+
+namespace Aaru.Helpers;
+
+using System.IO;
+
+public static class Extensions
+{
+    /// <summary>
+    ///     When overridden in a derived class, reads a sequence of bytes from the current stream and advances the
+    ///     position within the stream by the number of bytes read.<br /> Guarantees the whole count of bytes is read or EOF is
+    ///     found
+    /// </summary>
+    /// <param name="s">Stream to extend</param>
+    /// <param name="buffer">
+    ///     An array of bytes. When this method returns, the buffer contains the specified byte array with the
+    ///     values between <see cref="offset" /> and (<see cref="offset" /> + <see cref="count" /> - 1) replaced by the bytes
+    ///     read from the current source.
+    /// </param>
+    /// <param name="offset">
+    ///     The zero-based byte offset in <see cref="buffer" /> at which to begin storing the data read from
+    ///     the current stream.
+    /// </param>
+    /// <param name="count">The maximum number of bytes to be read from the current stream.</param>
+    /// <returns>
+    ///     The total number of bytes read into the buffer. This can be less than the number of bytes requested if the end
+    ///     of the stream has been reached.
+    /// </returns>
+    public static int EnsureRead(this Stream s, byte[] buffer, int offset, int count)
+    {
+        var pos = 0;
+        int read;
+
+        do
+        {
+            read =  s.Read(buffer, pos + offset, count - pos);
+            pos  += read;
+        } while(read > 0);
+
+        return pos;
+    }
+}