jeudi 9 mars 2017

Reading an utf8 encoded xml file in C#: the stream solution

All is in the title.
using (Stream str = System.IO.File.Open(@"fileName.xml", FileMode.Open)) {
    XmlReaderSettings p = new XmlReaderSettings {
        DtdProcessing = DtdProcessing.Parse
    using (XmlReader xr = XmlReader.Create(new StreamReader(str, Encoding.UTF8), p)) {
        XDocument xDoc = XDocument.Load(xr);
        // or
        //XElement xEl = XElement.Load(xr);
        //do your stuff here.

mercredi 1 mars 2017

dotnet restore hangs then time out with 100000ms

Especially on W7/x64

I found the solution here:

For several people it seems to be related to network interface (VMWare, VirtualBox...). For me the following unleash the restore:
Using "procmon" I found something strange happening in the lock files in %TEMP%\NugetScratch. I deleted that folder and everything started to work again and CI builds now work perfectly.
Happy restore!

vendredi 22 juillet 2016

linux and wifi troubleshooting

this is not (at all) exhaustive

first test: is the harware enabled ?
sudo rfkill list
if the command shows:
Hard bloked: yes
this means that your wifi switch is on postion OFF.

mardi 8 mars 2016

Commands you must know for ACMESharp

To complete the QuickStart from you may encounter some troubles. Among them:

----- I -----
The given key was not present in the dictionary

The solution is given by one of the issue.

This his formally an extract/copy from From this link one can read:

There are a few bookkeeping cmdlets you can run to make sure the parameters to the Complete-* cmdlet are valid:
  • Get-ACMEIdentifier -- with no arguments, this cmdlet will list all the current Identifiers you have in the Vault; if you give it an Identifier reference (e.g. sequence number, Alias or GUID) it will give you more details about that particular Identifier
  • Get-ACMEChallengeHandlerProfile -ListChallengeTypes -- this will return the list of all Challenge Types that are currently registered and available in the current PS session, e.g. dns-01, http-01
  • Get-ACMEChallengeHandlerProfile -ListChallengeHandlers -- this will return the list of all Challenge Handlers that are currently registered and available in the current PS session, e.g. manual, iis, awsRoute53, awsS3
  • Get-ACMEChallengeHandlerProfile -GetChallengeHandler iis -ParametersOnly -- this form of the cmdlet will list details about the parameters that must or may be specified for the named Challenge Handler type
With these cmdlets you can ensure that the parameters to your Complete-ACMEChallenge call are all correct, for example that the Identifier reference is valid. If you run these and everything seems to be specified correctly and you still get this error, then there might be a bug somewhere and we can trace through that.

----- II -----
Stuck in the pending status

The solution can be found here:

In short using the following command : (Update-ACMEIdentifier dns1 -ChallengeType http-01).Challenges should exhibit that one among three of the challenges is valid.

----- III -----
Cannot export PKCS12; Issuer certificate hasn't been resolved

The solution can be found here:

In short an Update-ACMECertificate certAlias solves the problem.

lundi 14 septembre 2015

Nearest neighborS search by Binary Partition Tree

There are a lot of excellent references on Internet, one of them is:

The missing part: some code to play around. Let's try to make something generic. What to we need to make a class partitionable ?

    public interface IIsPartionableByBT {
        Int32 Id { get; }

        float BTX { get; }
        float BTY { get; }
        float BTZ { get; }

        float DistTo(IIsPartionableByBT c);

    public delegate float BTCooProjector(IIsPartionableByBT coo);

We also need Cells/Nodes for the tree:

    public class MbtBSPNode<T> where T :  IIsPartionableByBT {
        public MbtBSPNode<T> Parent { get; set; }
        public T Cell { get; set; }
        public MbtBSPNode<T> Left { get; set; }
        public MbtBSPNode<T> Right { get; set; }

        public ICollection<MbtBSPNode<T>> Cells { get; set; }

        public UInt32 Depth { get { if (Parent == null) return 0; return Parent.Depth + 1; } }

And the tree himself:

    public class MbtBSPTree<T> where T : class, IIsPartionableByBT {
        public MbtBSPNode<T> Root { get; private set; }

        public UInt16 SplitDepthBy { get; private set; }

        public UInt16 LimitDepthTo { get; private set; }

        public MbtBSPTree(IEnumerable<T> l, UInt16 splitDepthBy = 0, UInt16 limitDepthTo = 0) {
            if (SplitDepthBy == 0) {
                if (l.Min(x => x.BTZ) == l.Max(x => x.BTZ)) {
                    SplitDepthBy = 2;
                } else {
                    SplitDepthBy = 3;
            } else {
                SplitDepthBy = splitDepthBy;
            LimitDepthTo = limitDepthTo;

            Root = BuildBSPTree(l, 0);

        public BTCooProjector DefProjector(UInt16 axis) {
            switch (axis) {
                case 0:
                    return (n) => n.BTX;
                case 1:
                    return (n) => n.BTY;
                case 2:
                    return (n) => n.BTZ;
                    throw new Exception("valeur de split de profondeur non gérée");

        public MbtBSPNode<T> BuildBSPTree(IEnumerable<T> l, UInt16 depth, MbtBSPNode<T> p = null) {
            if (l.Count() == 0)
                return null;
            UInt16 axis = (UInt16)(depth % SplitDepthBy);

            MbtBSPNode<T> n = new MbtBSPNode<T>();
            n.Parent = p;

            if (LimitDepthTo > 0 && depth == LimitDepthTo) {
                n.Cells = new List<MbtBSPNode<T>>();
                foreach (T cc in l) {
                    n.Cells.Add(new MbtBSPNode<T> { Cell = cc });
            } else {
                Double med = Double.MinValue;
                List<T> ll = new List<T>();
                List<T> lr = new List<T>();

                BTCooProjector proj = DefProjector((UInt16)(depth % SplitDepthBy));
                med = l.Median(x => proj(x));
                foreach (T c in l) {
                    if (proj(c) < med) {
                    } else {
                        if (proj(c) == med) {
                            if (n.Cell == null)
                                n.Cell = c;
                        } else {

                if (depth <= 2) {
                    //this will lead to 8 threads
                    Task<MbtBSPNode<T>> tl = Task<MbtBSPNode<T>>.Factory.StartNew(() =>
                        BuildBSPTree(ll, (UInt16)(depth + 1), n));
                    n.Right = BuildBSPTree(lr, (UInt16)(depth + 1), n);
                    //synchro thread
                    n.Left = tl.Result;
                } else {
                    n.Left = BuildBSPTree(ll, (UInt16)(depth + 1), n);
                    n.Right = BuildBSPTree(lr, (UInt16)(depth + 1), n);

            return n;

        public Int32 ScannedNodeNumber { get; set; }

        public IEnumerable<MbtBSPNode<T>> GetNearestNodes(T cel, float radius) {
            ScannedNodeNumber = 0;
            MbtBSPNode<T> current;
            Queue<MbtBSPNode<T>> q = new Queue<MbtBSPNode<T>>();

            while (q.Count > 0) {
                current = q.Dequeue();
                BTCooProjector proj;

                if (current.Cell != null) {
                    if (cel.DistTo(current.Cell) <= radius && cel.Id != current.Cell.Id) {
                        yield return current;

                    proj = DefProjector((UInt16)(current.Depth % SplitDepthBy));

                    if (proj(cel) - radius <= proj(current.Cell)) {
                        if (current.Left != null)
                    if (proj(cel) + radius > proj(current.Cell)) {
                        if (current.Right != null)

                if (current.Cells != null) {
                    foreach (MbtBSPNode<T> cc in current.Cells) {
                        if (cel.Id != cc.Cell.Id && cel.DistTo(cc.Cell) <= radius)
                            yield return cc;


One can find a median algorithm in here:

jeudi 14 mai 2015

Coloring cells in an OpenXml SpreadsheetDocument

Tow days, and many readings. That's the time I needed to figure out how to set a cell color in an openXml spreadsheet.

It finally ends by the use of the OpenXml SDK Productivity Tool.

The main point seems to be that there must be a minimal stylesheet in the spreadsheet. Among other, this minimal stylesheet must comprise s two Fills. This styleshett may be generated by the following code:

private void GenerateWorkbookStylesPartContent(WorkbookPart workbookPart, String partId) {
    WorkbookStylesPart wsp = workbookPart.AddNewPart(partId);

    Stylesheet stylesheet = new Stylesheet() { 
        MCAttributes = new MarkupCompatibilityAttributes() { Ignorable = "x14ac" } };

    Fonts fonts = new Fonts() { Count = (UInt32Value)1U, KnownFonts = true };
    Font font = new Font();
    FontSize fontSize = new FontSize() { Val = 11D };
    Color color = new Color() { Theme = (UInt32Value)1U };
    FontName fontName = new FontName() { Val = "Calibri" };
    FontFamilyNumbering fontFamilyNumbering = new FontFamilyNumbering() { Val = 2 };
    FontScheme fontScheme = new FontScheme() { Val = FontSchemeValues.Minor };
    stylesheet.Fonts = fonts;

    Borders borders = new Borders() { Count = (UInt32Value)1U };
    Border border = new Border();
    LeftBorder leftBorder = new LeftBorder();
    RightBorder rightBorder = new RightBorder();
    TopBorder topBorder = new TopBorder();
    BottomBorder bottomBorder = new BottomBorder();
    DiagonalBorder diagonalBorder = new DiagonalBorder();
    stylesheet.Borders = borders;

    stylesheet.Fills = new Fills();
    Fill f = new Fill { PatternFill = 
        new PatternFill { PatternType = PatternValues.None}};
    stylesheet.Fills.Append(new Fill { PatternFill = 
        new PatternFill { PatternType = PatternValues.Gray125 } });

    CellFormats cellFormats = new CellFormats() { Count = (UInt32Value)1U };
    CellFormat cellFormat = new CellFormat() { 
        NumberFormatId = (UInt32Value)0U, 
        FontId = (UInt32Value)0U, 
        FillId = (UInt32Value)0U, 
        BorderId = (UInt32Value)0U, 
        FormatId = (UInt32Value)0U };
    stylesheet.CellFormats = cellFormats;

    CellStyles cellStyles = new CellStyles() { Count = (UInt32Value)1U };
    CellStyle cellStyle = new CellStyle() { 
        Name = "Normal", FormatId = (UInt32Value)0U, BuiltinId = (UInt32Value)0U };
    stylesheet.CellStyles = cellStyles;

    CellStyleFormats cellStyleFormats = new CellStyleFormats() { Count = (UInt32Value)1U };
    CellFormat cellFormat2 = new CellFormat() { 
        NumberFormatId = (UInt32Value)0U, 
        FontId = (UInt32Value)0U, 
        FillId = (UInt32Value)0U, 
        BorderId = (UInt32Value)0U };
    stylesheet.CellStyleFormats = cellStyleFormats;


    wsp.Stylesheet = stylesheet;

From here, all what remain to do is handle the color in the cells, during the process I use a dictionary to avoid querying the stylesheet. In my case the key type is System.Drawing.Color because I'm exporting a DataGridView but, of course this type can be of any type you need.

    private Dictionary _colors = 
        new Dictionary();

Then, somewhere in the code:

UInt32 cellStyleUid = 0;
if ( col != System.Drawing.Color.Transparent) {
    if (!_colors.ContainsKey(col)) {
        //that is the style does not exists for this color
        if (_ssDoc.WorkbookPart.WorkbookStylesPart == null) {
            GenerateWorkbookStylesPartContent(_ssDoc.WorkbookPart, "rId5");

        //Create the Fill
        Fill fill = new Fill();
        PatternFill pf = new PatternFill { PatternType = PatternValues.Solid };
        ForegroundColor fgc = new ForegroundColor { 
             Rgb = HexBinaryValue.FromString(Convert.ToString(col.ToArgb(), 16)) };
        BackgroundColor bgc = new BackgroundColor() { Indexed = (UInt32Value)64U };
        //update the stylesheet
        Int32 iFill = _ssDoc.WorkbookPart.WorkbookStylesPart.Stylesheet.Fills.Count() - 1;
        _ssDoc.WorkbookPart.WorkbookStylesPart.Stylesheet.Fills.Count = (UInt32)(iFill + 1);

        //Create the CellFormat to use the created Fill
        CellFormat lcf = 
        CellFormat cf = new CellFormat { 
            NumberFormatId = lcf.NumberFormatId,
            FontId = lcf.FontId,
            FillId = (UInt32Value)(UInt32)iFill,
            BorderId = lcf.BorderId,
            FormatId = lcf.FormatId,
            ApplyFill = true,
            ApplyFont = lcf.ApplyFont

        //update the stylesheet 
        Int32 iCellFormat = 
            _ssDoc.WorkbookPart.WorkbookStylesPart.Stylesheet.CellFormats.Count() - 1;
        _ssDoc.WorkbookPart.WorkbookStylesPart.Stylesheet.CellFormats.Count = 
            (UInt32)(iCellFormat + 1);

        //put the index of the new CellFormat in the buffer
        _colors.Add(col, (UInt32)iCellFormat);

    //retrieve the index of the cell format for the color
    cellStyleUid = _colors[col];

It remains to use the updated stylesheet at the cell level. With cell being of type DocumentFormat.OpenXml.Spreadsheet.Cell

if (cellStyleUid != 0)
    cell.StyleIndex = cellStyleUid;

Et voilà !

lundi 27 avril 2015

Secure connection strings in app.config for a desktop application

The goal is to get away as little as possible of the standard.

In this case the standard is : Encrypting Configuration Information Using Protected Configuration

In short: use a ProtectedConfigurationProvider. The .Net Framework provides two of them:

The main inconvenience of those providers comes from the fact that they have been designed for web applications: that are applications in which the securisable is the application server. That is one web.config in one machine

With a desktop application you have a plurality of app.config

Said providers are machine based, i.e. there is one configuration file per machine. In other words, the configuration file of one machine can't be used by another because of different encryption keys.

Fortunately the .Net Framework provides an abstract class that can be overridden to built a custom provider.

Here is a sample

The DLL:

using System;
using System.Configuration;
using System.Xml;

namespace MBT.ProtectedConfigurationProviders {

    public class WeakProtectedConfigurationProvider : ProtectedConfigurationProvider {        
        public override void Initialize(string name, 
            System.Collections.Specialized.NameValueCollection config) {
            base.Initialize(name, config);

        public override System.Xml.XmlNode Decrypt(System.Xml.XmlNode encryptedNode) {
            string decryptedData =

            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.PreserveWhitespace = true;

            return xmlDoc.DocumentElement;

        public override System.Xml.XmlNode Encrypt(System.Xml.XmlNode node) {
            string encryptedData = EncryptString(node.OuterXml);

            XmlDocument xmlDoc = new XmlDocument();
            xmlDoc.PreserveWhitespace = true;
            xmlDoc.LoadXml("" +
                encryptedData + "");

            return xmlDoc.DocumentElement;

        public static String EncryptString(String st) {
            return Convert.ToBase64String(WeakProtectedConfigurationProvider.GetBytes(st));

        public static String DecryptString(String st) {
            return WeakProtectedConfigurationProvider.GetString(Convert.FromBase64String(st));

        public static byte[] GetBytes(string str) {
            byte[] bytes = new byte[str.Length * sizeof(char)];
            System.Buffer.BlockCopy(str.ToCharArray(), 0, bytes, 0, bytes.Length);
            return bytes;

        public static string GetString(byte[] bytes) {
            char[] chars = new char[bytes.Length / sizeof(char)];
            System.Buffer.BlockCopy(bytes, 0, chars, 0, bytes.Length);
            return new string(chars);


Here the WEAK word is deliberately chosen. Base 64 encoding is not at all a cypher algorithm.

Then the Program:

using System;
using System.Configuration;

namespace bas {
    class Program {
        static void Main(string[] args) {
            //String cs = @"";

And finally the app.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration >
  <!-- xmlns=""-->
  <configProtectedData defaultProvider="WeakProtectedConfigurationProvider">
      <clear />
      <add name ="WeakProtectedConfigurationProvider" type="MBT.ProtectedConfigurationProviders.WeakProtectedConfigurationProvider, WeakProtectedConfigurationProvider"/>

  <connectionStrings configProtectionProvider="WeakProtectedConfigurationProvider">

At least two points are significant here. First:

<add name ="WeakProtectedConfigurationProvider"

Here to avoid a GAC registration, on use the syntax "type, assembly"


<configuration xmlns="">

One may want to use a namespace in configuration tag of app.config to avoid Visual Studio complaint. But, in my case this also leads to side effect: "side by side configuration error" which prevents application from starting. So, for now, I do without, and it runs well.

Thank you to StackOverflow for the StringToBytesToString.