En utilisant .NET, comment pouvez-vous trouver le type MIME d'un fichier en fonction de la signature du fichier et non de l'extension
https://stackoverflow.com/questions/58510
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09-06-2019 - |
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Je cherche un moyen simple d'obtenir un type MIME dont l'extension de fichier est incorrecte ou non indiquée, quelque chose de similaire à cette question uniquement en .Net.
La solution
Dans Urlmon.dll, il y a une fonction appelée FindMimeFromData.
De la documentation
La détection de type MIME, ou « reniflage de données », fait référence au processus de détermination d'un type MIME approprié à partir de données binaires.Le résultat final dépend d'une combinaison d'en-têtes de type MIME fournis par le serveur, de l'extension de fichier et/ou des données elles-mêmes.Habituellement, seuls les 256 premiers octets de données sont significatifs.
Alors, lisez les premiers (jusqu'à) 256 octets du fichier et transmettez-les à FindMimeFromData.
Autres conseils
J'ai finalement utilisé urlmon.dll.Je pensais qu'il y aurait un moyen plus simple mais cela fonctionne.J'inclus le code pour aider quelqu'un d'autre et me permettre de le retrouver si j'en ai besoin.
using System.Runtime.InteropServices;
...
[DllImport(@"urlmon.dll", CharSet = CharSet.Auto)]
private extern static System.UInt32 FindMimeFromData(
System.UInt32 pBC,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzUrl,
[MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer,
System.UInt32 cbSize,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzMimeProposed,
System.UInt32 dwMimeFlags,
out System.UInt32 ppwzMimeOut,
System.UInt32 dwReserverd
);
public static string getMimeFromFile(string filename)
{
if (!File.Exists(filename))
throw new FileNotFoundException(filename + " not found");
byte[] buffer = new byte[256];
using (FileStream fs = new FileStream(filename, FileMode.Open))
{
if (fs.Length >= 256)
fs.Read(buffer, 0, 256);
else
fs.Read(buffer, 0, (int)fs.Length);
}
try
{
System.UInt32 mimetype;
FindMimeFromData(0, null, buffer, 256, null, 0, out mimetype, 0);
System.IntPtr mimeTypePtr = new IntPtr(mimetype);
string mime = Marshal.PtrToStringUni(mimeTypePtr);
Marshal.FreeCoTaskMem(mimeTypePtr);
return mime;
}
catch (Exception e)
{
return "unknown/unknown";
}
}
J'ai trouvé une solution codée en dur, j'espère pouvoir aider quelqu'un :
public static class MIMEAssistant
{
private static readonly Dictionary<string, string> MIMETypesDictionary = new Dictionary<string, string>
{
{"ai", "application/postscript"},
{"aif", "audio/x-aiff"},
{"aifc", "audio/x-aiff"},
{"aiff", "audio/x-aiff"},
{"asc", "text/plain"},
{"atom", "application/atom+xml"},
{"au", "audio/basic"},
{"avi", "video/x-msvideo"},
{"bcpio", "application/x-bcpio"},
{"bin", "application/octet-stream"},
{"bmp", "image/bmp"},
{"cdf", "application/x-netcdf"},
{"cgm", "image/cgm"},
{"class", "application/octet-stream"},
{"cpio", "application/x-cpio"},
{"cpt", "application/mac-compactpro"},
{"csh", "application/x-csh"},
{"css", "text/css"},
{"dcr", "application/x-director"},
{"dif", "video/x-dv"},
{"dir", "application/x-director"},
{"djv", "image/vnd.djvu"},
{"djvu", "image/vnd.djvu"},
{"dll", "application/octet-stream"},
{"dmg", "application/octet-stream"},
{"dms", "application/octet-stream"},
{"doc", "application/msword"},
{"docx","application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
{"dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
{"docm","application/vnd.ms-word.document.macroEnabled.12"},
{"dotm","application/vnd.ms-word.template.macroEnabled.12"},
{"dtd", "application/xml-dtd"},
{"dv", "video/x-dv"},
{"dvi", "application/x-dvi"},
{"dxr", "application/x-director"},
{"eps", "application/postscript"},
{"etx", "text/x-setext"},
{"exe", "application/octet-stream"},
{"ez", "application/andrew-inset"},
{"gif", "image/gif"},
{"gram", "application/srgs"},
{"grxml", "application/srgs+xml"},
{"gtar", "application/x-gtar"},
{"hdf", "application/x-hdf"},
{"hqx", "application/mac-binhex40"},
{"htm", "text/html"},
{"html", "text/html"},
{"ice", "x-conference/x-cooltalk"},
{"ico", "image/x-icon"},
{"ics", "text/calendar"},
{"ief", "image/ief"},
{"ifb", "text/calendar"},
{"iges", "model/iges"},
{"igs", "model/iges"},
{"jnlp", "application/x-java-jnlp-file"},
{"jp2", "image/jp2"},
{"jpe", "image/jpeg"},
{"jpeg", "image/jpeg"},
{"jpg", "image/jpeg"},
{"js", "application/x-javascript"},
{"kar", "audio/midi"},
{"latex", "application/x-latex"},
{"lha", "application/octet-stream"},
{"lzh", "application/octet-stream"},
{"m3u", "audio/x-mpegurl"},
{"m4a", "audio/mp4a-latm"},
{"m4b", "audio/mp4a-latm"},
{"m4p", "audio/mp4a-latm"},
{"m4u", "video/vnd.mpegurl"},
{"m4v", "video/x-m4v"},
{"mac", "image/x-macpaint"},
{"man", "application/x-troff-man"},
{"mathml", "application/mathml+xml"},
{"me", "application/x-troff-me"},
{"mesh", "model/mesh"},
{"mid", "audio/midi"},
{"midi", "audio/midi"},
{"mif", "application/vnd.mif"},
{"mov", "video/quicktime"},
{"movie", "video/x-sgi-movie"},
{"mp2", "audio/mpeg"},
{"mp3", "audio/mpeg"},
{"mp4", "video/mp4"},
{"mpe", "video/mpeg"},
{"mpeg", "video/mpeg"},
{"mpg", "video/mpeg"},
{"mpga", "audio/mpeg"},
{"ms", "application/x-troff-ms"},
{"msh", "model/mesh"},
{"mxu", "video/vnd.mpegurl"},
{"nc", "application/x-netcdf"},
{"oda", "application/oda"},
{"ogg", "application/ogg"},
{"pbm", "image/x-portable-bitmap"},
{"pct", "image/pict"},
{"pdb", "chemical/x-pdb"},
{"pdf", "application/pdf"},
{"pgm", "image/x-portable-graymap"},
{"pgn", "application/x-chess-pgn"},
{"pic", "image/pict"},
{"pict", "image/pict"},
{"png", "image/png"},
{"pnm", "image/x-portable-anymap"},
{"pnt", "image/x-macpaint"},
{"pntg", "image/x-macpaint"},
{"ppm", "image/x-portable-pixmap"},
{"ppt", "application/vnd.ms-powerpoint"},
{"pptx","application/vnd.openxmlformats-officedocument.presentationml.presentation"},
{"potx","application/vnd.openxmlformats-officedocument.presentationml.template"},
{"ppsx","application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
{"ppam","application/vnd.ms-powerpoint.addin.macroEnabled.12"},
{"pptm","application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
{"potm","application/vnd.ms-powerpoint.template.macroEnabled.12"},
{"ppsm","application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
{"ps", "application/postscript"},
{"qt", "video/quicktime"},
{"qti", "image/x-quicktime"},
{"qtif", "image/x-quicktime"},
{"ra", "audio/x-pn-realaudio"},
{"ram", "audio/x-pn-realaudio"},
{"ras", "image/x-cmu-raster"},
{"rdf", "application/rdf+xml"},
{"rgb", "image/x-rgb"},
{"rm", "application/vnd.rn-realmedia"},
{"roff", "application/x-troff"},
{"rtf", "text/rtf"},
{"rtx", "text/richtext"},
{"sgm", "text/sgml"},
{"sgml", "text/sgml"},
{"sh", "application/x-sh"},
{"shar", "application/x-shar"},
{"silo", "model/mesh"},
{"sit", "application/x-stuffit"},
{"skd", "application/x-koan"},
{"skm", "application/x-koan"},
{"skp", "application/x-koan"},
{"skt", "application/x-koan"},
{"smi", "application/smil"},
{"smil", "application/smil"},
{"snd", "audio/basic"},
{"so", "application/octet-stream"},
{"spl", "application/x-futuresplash"},
{"src", "application/x-wais-source"},
{"sv4cpio", "application/x-sv4cpio"},
{"sv4crc", "application/x-sv4crc"},
{"svg", "image/svg+xml"},
{"swf", "application/x-shockwave-flash"},
{"t", "application/x-troff"},
{"tar", "application/x-tar"},
{"tcl", "application/x-tcl"},
{"tex", "application/x-tex"},
{"texi", "application/x-texinfo"},
{"texinfo", "application/x-texinfo"},
{"tif", "image/tiff"},
{"tiff", "image/tiff"},
{"tr", "application/x-troff"},
{"tsv", "text/tab-separated-values"},
{"txt", "text/plain"},
{"ustar", "application/x-ustar"},
{"vcd", "application/x-cdlink"},
{"vrml", "model/vrml"},
{"vxml", "application/voicexml+xml"},
{"wav", "audio/x-wav"},
{"wbmp", "image/vnd.wap.wbmp"},
{"wbmxl", "application/vnd.wap.wbxml"},
{"wml", "text/vnd.wap.wml"},
{"wmlc", "application/vnd.wap.wmlc"},
{"wmls", "text/vnd.wap.wmlscript"},
{"wmlsc", "application/vnd.wap.wmlscriptc"},
{"wrl", "model/vrml"},
{"xbm", "image/x-xbitmap"},
{"xht", "application/xhtml+xml"},
{"xhtml", "application/xhtml+xml"},
{"xls", "application/vnd.ms-excel"},
{"xml", "application/xml"},
{"xpm", "image/x-xpixmap"},
{"xsl", "application/xml"},
{"xlsx","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
{"xltx","application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
{"xlsm","application/vnd.ms-excel.sheet.macroEnabled.12"},
{"xltm","application/vnd.ms-excel.template.macroEnabled.12"},
{"xlam","application/vnd.ms-excel.addin.macroEnabled.12"},
{"xlsb","application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
{"xslt", "application/xslt+xml"},
{"xul", "application/vnd.mozilla.xul+xml"},
{"xwd", "image/x-xwindowdump"},
{"xyz", "chemical/x-xyz"},
{"zip", "application/zip"}
};
public static string GetMIMEType(string fileName)
{
//get file extension
string extension = Path.GetExtension(fileName).ToLowerInvariant();
if (extension.Length > 0 &&
MIMETypesDictionary.ContainsKey(extension.Remove(0, 1)))
{
return MIMETypesDictionary[extension.Remove(0, 1)];
}
return "unknown/unknown";
}
}
Modifier:Utilisez simplement Détective Mime
J'utilise des séquences de tableaux d'octets pour déterminer le type MIME correct d'un fichier donné.L'avantage de cela par rapport au simple examen de l'extension du nom de fichier est que si un utilisateur devait renommer un fichier pour contourner certaines restrictions de téléchargement de type de fichier, l'extension du nom de fichier ne parviendrait pas à le détecter.D'un autre côté, obtenir la signature du fichier via un tableau d'octets empêchera ce comportement malveillant de se produire.
Voici un exemple en C# :
public class MimeType
{
private static readonly byte[] BMP = { 66, 77 };
private static readonly byte[] DOC = { 208, 207, 17, 224, 161, 177, 26, 225 };
private static readonly byte[] EXE_DLL = { 77, 90 };
private static readonly byte[] GIF = { 71, 73, 70, 56 };
private static readonly byte[] ICO = { 0, 0, 1, 0 };
private static readonly byte[] JPG = { 255, 216, 255 };
private static readonly byte[] MP3 = { 255, 251, 48 };
private static readonly byte[] OGG = { 79, 103, 103, 83, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0 };
private static readonly byte[] PDF = { 37, 80, 68, 70, 45, 49, 46 };
private static readonly byte[] PNG = { 137, 80, 78, 71, 13, 10, 26, 10, 0, 0, 0, 13, 73, 72, 68, 82 };
private static readonly byte[] RAR = { 82, 97, 114, 33, 26, 7, 0 };
private static readonly byte[] SWF = { 70, 87, 83 };
private static readonly byte[] TIFF = { 73, 73, 42, 0 };
private static readonly byte[] TORRENT = { 100, 56, 58, 97, 110, 110, 111, 117, 110, 99, 101 };
private static readonly byte[] TTF = { 0, 1, 0, 0, 0 };
private static readonly byte[] WAV_AVI = { 82, 73, 70, 70 };
private static readonly byte[] WMV_WMA = { 48, 38, 178, 117, 142, 102, 207, 17, 166, 217, 0, 170, 0, 98, 206, 108 };
private static readonly byte[] ZIP_DOCX = { 80, 75, 3, 4 };
public static string GetMimeType(byte[] file, string fileName)
{
string mime = "application/octet-stream"; //DEFAULT UNKNOWN MIME TYPE
//Ensure that the filename isn't empty or null
if (string.IsNullOrWhiteSpace(fileName))
{
return mime;
}
//Get the file extension
string extension = Path.GetExtension(fileName) == null
? string.Empty
: Path.GetExtension(fileName).ToUpper();
//Get the MIME Type
if (file.Take(2).SequenceEqual(BMP))
{
mime = "image/bmp";
}
else if (file.Take(8).SequenceEqual(DOC))
{
mime = "application/msword";
}
else if (file.Take(2).SequenceEqual(EXE_DLL))
{
mime = "application/x-msdownload"; //both use same mime type
}
else if (file.Take(4).SequenceEqual(GIF))
{
mime = "image/gif";
}
else if (file.Take(4).SequenceEqual(ICO))
{
mime = "image/x-icon";
}
else if (file.Take(3).SequenceEqual(JPG))
{
mime = "image/jpeg";
}
else if (file.Take(3).SequenceEqual(MP3))
{
mime = "audio/mpeg";
}
else if (file.Take(14).SequenceEqual(OGG))
{
if (extension == ".OGX")
{
mime = "application/ogg";
}
else if (extension == ".OGA")
{
mime = "audio/ogg";
}
else
{
mime = "video/ogg";
}
}
else if (file.Take(7).SequenceEqual(PDF))
{
mime = "application/pdf";
}
else if (file.Take(16).SequenceEqual(PNG))
{
mime = "image/png";
}
else if (file.Take(7).SequenceEqual(RAR))
{
mime = "application/x-rar-compressed";
}
else if (file.Take(3).SequenceEqual(SWF))
{
mime = "application/x-shockwave-flash";
}
else if (file.Take(4).SequenceEqual(TIFF))
{
mime = "image/tiff";
}
else if (file.Take(11).SequenceEqual(TORRENT))
{
mime = "application/x-bittorrent";
}
else if (file.Take(5).SequenceEqual(TTF))
{
mime = "application/x-font-ttf";
}
else if (file.Take(4).SequenceEqual(WAV_AVI))
{
mime = extension == ".AVI" ? "video/x-msvideo" : "audio/x-wav";
}
else if (file.Take(16).SequenceEqual(WMV_WMA))
{
mime = extension == ".WMA" ? "audio/x-ms-wma" : "video/x-ms-wmv";
}
else if (file.Take(4).SequenceEqual(ZIP_DOCX))
{
mime = extension == ".DOCX" ? "application/vnd.openxmlformats-officedocument.wordprocessingml.document" : "application/x-zip-compressed";
}
return mime;
}
}
Notez que j'ai géré les types de fichiers DOCX différemment puisque DOCX n'est en réalité qu'un fichier ZIP.Dans ce scénario, je vérifie simplement l’extension du fichier une fois que j’ai vérifié qu’il possède cette séquence.Cet exemple est loin d’être complet pour certaines personnes, mais vous pouvez facilement ajouter le vôtre.
Si vous souhaitez ajouter plus de types MIME, vous pouvez obtenir les séquences de tableaux d'octets de nombreux types de fichiers différents d'ici.Aussi, voici une autre bonne ressource concernant les signatures de fichiers.
Ce que je fais souvent si tout le reste échoue, c'est parcourir plusieurs fichiers d'un type particulier que je recherche et rechercher un modèle dans la séquence d'octets des fichiers.En fin de compte, il s’agit toujours d’une vérification de base et ne peut pas être utilisée comme preuve à 100 % de la détermination des types de fichiers.
Si vous utilisez .NET Framework 4.5 ou supérieur, il existe désormais une méthode MimeMapping.GetMimeMapping(filename) qui renverra une chaîne avec le mappage Mime correct pour le nom de fichier transmis.Notez que cela utilise l'extension du fichier, pas les données du fichier lui-même.
La documentation est à http://msdn.microsoft.com/en-us/library/system.web.mimemapping.getmimemapping
Vous pouvez également consulter le registre.
using System.IO;
using Microsoft.Win32;
string GetMimeType(FileInfo fileInfo)
{
string mimeType = "application/unknown";
RegistryKey regKey = Registry.ClassesRoot.OpenSubKey(
fileInfo.Extension.ToLower()
);
if(regKey != null)
{
object contentType = regKey.GetValue("Content Type");
if(contentType != null)
mimeType = contentType.ToString();
}
return mimeType;
}
D'une manière ou d'une autre, vous devrez accéder à une base de données de MIME - qu'ils soient mappés à partir d'extensions ou de nombres magiques est quelque peu trivial - le registre Windows est l'un de ces endroits.Pour une solution indépendante de la plate-forme, il faudrait cependant expédier cette base de données avec le code (ou en tant que bibliothèque autonome).
J'utilise une solution hybride :
using System.Runtime.InteropServices;
[DllImport (@"urlmon.dll", CharSet = CharSet.Auto)]
private extern static System.UInt32 FindMimeFromData(
System.UInt32 pBC,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzUrl,
[MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer,
System.UInt32 cbSize,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzMimeProposed,
System.UInt32 dwMimeFlags,
out System.UInt32 ppwzMimeOut,
System.UInt32 dwReserverd
);
private string GetMimeFromRegistry (string Filename)
{
string mime = "application/octetstream";
string ext = System.IO.Path.GetExtension(Filename).ToLower();
Microsoft.Win32.RegistryKey rk = Microsoft.Win32.Registry.ClassesRoot.OpenSubKey(ext);
if (rk != null && rk.GetValue("Content Type") != null)
mime = rk.GetValue("Content Type").ToString();
return mime;
}
public string GetMimeTypeFromFileAndRegistry (string filename)
{
if (!File.Exists(filename))
{
return GetMimeFromRegistry (filename);
}
byte[] buffer = new byte[256];
using (FileStream fs = new FileStream(filename, FileMode.Open))
{
if (fs.Length >= 256)
fs.Read(buffer, 0, 256);
else
fs.Read(buffer, 0, (int)fs.Length);
}
try
{
System.UInt32 mimetype;
FindMimeFromData(0, null, buffer, 256, null, 0, out mimetype, 0);
System.IntPtr mimeTypePtr = new IntPtr(mimetype);
string mime = Marshal.PtrToStringUni(mimeTypePtr);
Marshal.FreeCoTaskMem(mimeTypePtr);
if (string.IsNullOrWhiteSpace (mime) ||
mime =="text/plain" || mime == "application/octet-stream")
{
return GetMimeFromRegistry (filename);
}
return mime;
}
catch (Exception e)
{
return GetMimeFromRegistry (filename);
}
}
J'ai trouvé celui-ci utile.Pour les développeurs VB.NET :
Public Shared Function GetFromFileName(ByVal fileName As String) As String
Return GetFromExtension(Path.GetExtension(fileName).Remove(0, 1))
End Function
Public Shared Function GetFromExtension(ByVal extension As String) As String
If extension.StartsWith("."c) Then
extension = extension.Remove(0, 1)
End If
If MIMETypesDictionary.ContainsKey(extension) Then
Return MIMETypesDictionary(extension)
End If
Return "unknown/unknown"
End Function
Private Shared ReadOnly MIMETypesDictionary As New Dictionary(Of String, String)() From { _
{"ai", "application/postscript"}, _
{"aif", "audio/x-aiff"}, _
{"aifc", "audio/x-aiff"}, _
{"aiff", "audio/x-aiff"}, _
{"asc", "text/plain"}, _
{"atom", "application/atom+xml"}, _
{"au", "audio/basic"}, _
{"avi", "video/x-msvideo"}, _
{"bcpio", "application/x-bcpio"}, _
{"bin", "application/octet-stream"}, _
{"bmp", "image/bmp"}, _
{"cdf", "application/x-netcdf"}, _
{"cgm", "image/cgm"}, _
{"class", "application/octet-stream"}, _
{"cpio", "application/x-cpio"}, _
{"cpt", "application/mac-compactpro"}, _
{"csh", "application/x-csh"}, _
{"css", "text/css"}, _
{"dcr", "application/x-director"}, _
{"dif", "video/x-dv"}, _
{"dir", "application/x-director"}, _
{"djv", "image/vnd.djvu"}, _
{"djvu", "image/vnd.djvu"}, _
{"dll", "application/octet-stream"}, _
{"dmg", "application/octet-stream"}, _
{"dms", "application/octet-stream"}, _
{"doc", "application/msword"}, _
{"dtd", "application/xml-dtd"}, _
{"dv", "video/x-dv"}, _
{"dvi", "application/x-dvi"}, _
{"dxr", "application/x-director"}, _
{"eps", "application/postscript"}, _
{"etx", "text/x-setext"}, _
{"exe", "application/octet-stream"}, _
{"ez", "application/andrew-inset"}, _
{"gif", "image/gif"}, _
{"gram", "application/srgs"}, _
{"grxml", "application/srgs+xml"}, _
{"gtar", "application/x-gtar"}, _
{"hdf", "application/x-hdf"}, _
{"hqx", "application/mac-binhex40"}, _
{"htm", "text/html"}, _
{"html", "text/html"}, _
{"ice", "x-conference/x-cooltalk"}, _
{"ico", "image/x-icon"}, _
{"ics", "text/calendar"}, _
{"ief", "image/ief"}, _
{"ifb", "text/calendar"}, _
{"iges", "model/iges"}, _
{"igs", "model/iges"}, _
{"jnlp", "application/x-java-jnlp-file"}, _
{"jp2", "image/jp2"}, _
{"jpe", "image/jpeg"}, _
{"jpeg", "image/jpeg"}, _
{"jpg", "image/jpeg"}, _
{"js", "application/x-javascript"}, _
{"kar", "audio/midi"}, _
{"latex", "application/x-latex"}, _
{"lha", "application/octet-stream"}, _
{"lzh", "application/octet-stream"}, _
{"m3u", "audio/x-mpegurl"}, _
{"m4a", "audio/mp4a-latm"}, _
{"m4b", "audio/mp4a-latm"}, _
{"m4p", "audio/mp4a-latm"}, _
{"m4u", "video/vnd.mpegurl"}, _
{"m4v", "video/x-m4v"}, _
{"mac", "image/x-macpaint"}, _
{"man", "application/x-troff-man"}, _
{"mathml", "application/mathml+xml"}, _
{"me", "application/x-troff-me"}, _
{"mesh", "model/mesh"}, _
{"mid", "audio/midi"}, _
{"midi", "audio/midi"}, _
{"mif", "application/vnd.mif"}, _
{"mov", "video/quicktime"}, _
{"movie", "video/x-sgi-movie"}, _
{"mp2", "audio/mpeg"}, _
{"mp3", "audio/mpeg"}, _
{"mp4", "video/mp4"}, _
{"mpe", "video/mpeg"}, _
{"mpeg", "video/mpeg"}, _
{"mpg", "video/mpeg"}, _
{"mpga", "audio/mpeg"}, _
{"ms", "application/x-troff-ms"}, _
{"msh", "model/mesh"}, _
{"mxu", "video/vnd.mpegurl"}, _
{"nc", "application/x-netcdf"}, _
{"oda", "application/oda"}, _
{"ogg", "application/ogg"}, _
{"pbm", "image/x-portable-bitmap"}, _
{"pct", "image/pict"}, _
{"pdb", "chemical/x-pdb"}, _
{"pdf", "application/pdf"}, _
{"pgm", "image/x-portable-graymap"}, _
{"pgn", "application/x-chess-pgn"}, _
{"pic", "image/pict"}, _
{"pict", "image/pict"}, _
{"png", "image/png"}, _
{"pnm", "image/x-portable-anymap"}, _
{"pnt", "image/x-macpaint"}, _
{"pntg", "image/x-macpaint"}, _
{"ppm", "image/x-portable-pixmap"}, _
{"ppt", "application/vnd.ms-powerpoint"}, _
{"ps", "application/postscript"}, _
{"qt", "video/quicktime"}, _
{"qti", "image/x-quicktime"}, _
{"qtif", "image/x-quicktime"}, _
{"ra", "audio/x-pn-realaudio"}, _
{"ram", "audio/x-pn-realaudio"}, _
{"ras", "image/x-cmu-raster"}, _
{"rdf", "application/rdf+xml"}, _
{"rgb", "image/x-rgb"}, _
{"rm", "application/vnd.rn-realmedia"}, _
{"roff", "application/x-troff"}, _
{"rtf", "text/rtf"}, _
{"rtx", "text/richtext"}, _
{"sgm", "text/sgml"}, _
{"sgml", "text/sgml"}, _
{"sh", "application/x-sh"}, _
{"shar", "application/x-shar"}, _
{"silo", "model/mesh"}, _
{"sit", "application/x-stuffit"}, _
{"skd", "application/x-koan"}, _
{"skm", "application/x-koan"}, _
{"skp", "application/x-koan"}, _
{"skt", "application/x-koan"}, _
{"smi", "application/smil"}, _
{"smil", "application/smil"}, _
{"snd", "audio/basic"}, _
{"so", "application/octet-stream"}, _
{"spl", "application/x-futuresplash"}, _
{"src", "application/x-wais-source"}, _
{"sv4cpio", "application/x-sv4cpio"}, _
{"sv4crc", "application/x-sv4crc"}, _
{"svg", "image/svg+xml"}, _
{"swf", "application/x-shockwave-flash"}, _
{"t", "application/x-troff"}, _
{"tar", "application/x-tar"}, _
{"tcl", "application/x-tcl"}, _
{"tex", "application/x-tex"}, _
{"texi", "application/x-texinfo"}, _
{"texinfo", "application/x-texinfo"}, _
{"tif", "image/tiff"}, _
{"tiff", "image/tiff"}, _
{"tr", "application/x-troff"}, _
{"tsv", "text/tab-separated-values"}, _
{"txt", "text/plain"}, _
{"ustar", "application/x-ustar"}, _
{"vcd", "application/x-cdlink"}, _
{"vrml", "model/vrml"}, _
{"vxml", "application/voicexml+xml"}, _
{"wav", "audio/x-wav"}, _
{"wbmp", "image/vnd.wap.wbmp"}, _
{"wbmxl", "application/vnd.wap.wbxml"}, _
{"wml", "text/vnd.wap.wml"}, _
{"wmlc", "application/vnd.wap.wmlc"}, _
{"wmls", "text/vnd.wap.wmlscript"}, _
{"wmlsc", "application/vnd.wap.wmlscriptc"}, _
{"wrl", "model/vrml"}, _
{"xbm", "image/x-xbitmap"}, _
{"xht", "application/xhtml+xml"}, _
{"xhtml", "application/xhtml+xml"}, _
{"xls", "application/vnd.ms-excel"}, _
{"xml", "application/xml"}, _
{"xpm", "image/x-xpixmap"}, _
{"xsl", "application/xml"}, _
{"xslt", "application/xslt+xml"}, _
{"xul", "application/vnd.mozilla.xul+xml"}, _
{"xwd", "image/x-xwindowdump"}, _
{"xyz", "chemical/x-xyz"}, _
{"zip", "application/zip"} _
}
Je pense que la bonne réponse est une combinaison des réponses de Steve Morgan et de Serguei.C'est ainsi que fonctionne Internet Explorer.L'appel pinvoke à FindMimeFromData ne fonctionne que pour 26 types MIME codés en dur.En outre, cela donnera des types MIME ambigus (tels que text/plain ou application/octet-stream) même s'il existe un type MIME plus spécifique et plus approprié.S'il ne parvient pas à fournir un bon type MIME, vous pouvez accéder au registre pour obtenir un type MIME plus spécifique.Le registre du serveur pourrait avoir des types MIME plus à jour.
Faire référence à: http://msdn.microsoft.com/en-us/library/ms775147(VS.85).aspx
Ce cours utilise les réponses précédentes pour essayer de 3 manières différentes :codé en fonction de l'extension, de l'API FindMimeFromData et de l'utilisation du registre.
using System;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;
using Microsoft.Win32;
namespace YourNamespace
{
public static class MimeTypeParser
{
[DllImport(@"urlmon.dll", CharSet = CharSet.Auto)]
private extern static System.UInt32 FindMimeFromData(
System.UInt32 pBC,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzUrl,
[MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer,
System.UInt32 cbSize,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzMimeProposed,
System.UInt32 dwMimeFlags,
out System.UInt32 ppwzMimeOut,
System.UInt32 dwReserverd
);
public static string GetMimeType(string sFilePath)
{
string sMimeType = GetMimeTypeFromList(sFilePath);
if (String.IsNullOrEmpty(sMimeType))
{
sMimeType = GetMimeTypeFromFile(sFilePath);
if (String.IsNullOrEmpty(sMimeType))
{
sMimeType = GetMimeTypeFromRegistry(sFilePath);
}
}
return sMimeType;
}
public static string GetMimeTypeFromList(string sFileNameOrPath)
{
string sMimeType = null;
string sExtensionWithoutDot = Path.GetExtension(sFileNameOrPath).Substring(1).ToLower();
if (!String.IsNullOrEmpty(sExtensionWithoutDot) && spDicMIMETypes.ContainsKey(sExtensionWithoutDot))
{
sMimeType = spDicMIMETypes[sExtensionWithoutDot];
}
return sMimeType;
}
public static string GetMimeTypeFromRegistry(string sFileNameOrPath)
{
string sMimeType = null;
string sExtension = Path.GetExtension(sFileNameOrPath).ToLower();
RegistryKey pKey = Registry.ClassesRoot.OpenSubKey(sExtension);
if (pKey != null && pKey.GetValue("Content Type") != null)
{
sMimeType = pKey.GetValue("Content Type").ToString();
}
return sMimeType;
}
public static string GetMimeTypeFromFile(string sFilePath)
{
string sMimeType = null;
if (File.Exists(sFilePath))
{
byte[] abytBuffer = new byte[256];
using (FileStream pFileStream = new FileStream(sFilePath, FileMode.Open))
{
if (pFileStream.Length >= 256)
{
pFileStream.Read(abytBuffer, 0, 256);
}
else
{
pFileStream.Read(abytBuffer, 0, (int)pFileStream.Length);
}
}
try
{
UInt32 unMimeType;
FindMimeFromData(0, null, abytBuffer, 256, null, 0, out unMimeType, 0);
IntPtr pMimeType = new IntPtr(unMimeType);
string sMimeTypeFromFile = Marshal.PtrToStringUni(pMimeType);
Marshal.FreeCoTaskMem(pMimeType);
if (!String.IsNullOrEmpty(sMimeTypeFromFile) && sMimeTypeFromFile != "text/plain" && sMimeTypeFromFile != "application/octet-stream")
{
sMimeType = sMimeTypeFromFile;
}
}
catch {}
}
return sMimeType;
}
private static readonly Dictionary<string, string> spDicMIMETypes = new Dictionary<string, string>
{
{"ai", "application/postscript"},
{"aif", "audio/x-aiff"},
{"aifc", "audio/x-aiff"},
{"aiff", "audio/x-aiff"},
{"asc", "text/plain"},
{"atom", "application/atom+xml"},
{"au", "audio/basic"},
{"avi", "video/x-msvideo"},
{"bcpio", "application/x-bcpio"},
{"bin", "application/octet-stream"},
{"bmp", "image/bmp"},
{"cdf", "application/x-netcdf"},
{"cgm", "image/cgm"},
{"class", "application/octet-stream"},
{"cpio", "application/x-cpio"},
{"cpt", "application/mac-compactpro"},
{"csh", "application/x-csh"},
{"css", "text/css"},
{"dcr", "application/x-director"},
{"dif", "video/x-dv"},
{"dir", "application/x-director"},
{"djv", "image/vnd.djvu"},
{"djvu", "image/vnd.djvu"},
{"dll", "application/octet-stream"},
{"dmg", "application/octet-stream"},
{"dms", "application/octet-stream"},
{"doc", "application/msword"},
{"docx","application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
{"dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
{"docm","application/vnd.ms-word.document.macroEnabled.12"},
{"dotm","application/vnd.ms-word.template.macroEnabled.12"},
{"dtd", "application/xml-dtd"},
{"dv", "video/x-dv"},
{"dvi", "application/x-dvi"},
{"dxr", "application/x-director"},
{"eps", "application/postscript"},
{"etx", "text/x-setext"},
{"exe", "application/octet-stream"},
{"ez", "application/andrew-inset"},
{"gif", "image/gif"},
{"gram", "application/srgs"},
{"grxml", "application/srgs+xml"},
{"gtar", "application/x-gtar"},
{"hdf", "application/x-hdf"},
{"hqx", "application/mac-binhex40"},
{"htc", "text/x-component"},
{"htm", "text/html"},
{"html", "text/html"},
{"ice", "x-conference/x-cooltalk"},
{"ico", "image/x-icon"},
{"ics", "text/calendar"},
{"ief", "image/ief"},
{"ifb", "text/calendar"},
{"iges", "model/iges"},
{"igs", "model/iges"},
{"jnlp", "application/x-java-jnlp-file"},
{"jp2", "image/jp2"},
{"jpe", "image/jpeg"},
{"jpeg", "image/jpeg"},
{"jpg", "image/jpeg"},
{"js", "application/x-javascript"},
{"kar", "audio/midi"},
{"latex", "application/x-latex"},
{"lha", "application/octet-stream"},
{"lzh", "application/octet-stream"},
{"m3u", "audio/x-mpegurl"},
{"m4a", "audio/mp4a-latm"},
{"m4b", "audio/mp4a-latm"},
{"m4p", "audio/mp4a-latm"},
{"m4u", "video/vnd.mpegurl"},
{"m4v", "video/x-m4v"},
{"mac", "image/x-macpaint"},
{"man", "application/x-troff-man"},
{"mathml", "application/mathml+xml"},
{"me", "application/x-troff-me"},
{"mesh", "model/mesh"},
{"mid", "audio/midi"},
{"midi", "audio/midi"},
{"mif", "application/vnd.mif"},
{"mov", "video/quicktime"},
{"movie", "video/x-sgi-movie"},
{"mp2", "audio/mpeg"},
{"mp3", "audio/mpeg"},
{"mp4", "video/mp4"},
{"mpe", "video/mpeg"},
{"mpeg", "video/mpeg"},
{"mpg", "video/mpeg"},
{"mpga", "audio/mpeg"},
{"ms", "application/x-troff-ms"},
{"msh", "model/mesh"},
{"mxu", "video/vnd.mpegurl"},
{"nc", "application/x-netcdf"},
{"oda", "application/oda"},
{"ogg", "application/ogg"},
{"pbm", "image/x-portable-bitmap"},
{"pct", "image/pict"},
{"pdb", "chemical/x-pdb"},
{"pdf", "application/pdf"},
{"pgm", "image/x-portable-graymap"},
{"pgn", "application/x-chess-pgn"},
{"pic", "image/pict"},
{"pict", "image/pict"},
{"png", "image/png"},
{"pnm", "image/x-portable-anymap"},
{"pnt", "image/x-macpaint"},
{"pntg", "image/x-macpaint"},
{"ppm", "image/x-portable-pixmap"},
{"ppt", "application/vnd.ms-powerpoint"},
{"pptx","application/vnd.openxmlformats-officedocument.presentationml.presentation"},
{"potx","application/vnd.openxmlformats-officedocument.presentationml.template"},
{"ppsx","application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
{"ppam","application/vnd.ms-powerpoint.addin.macroEnabled.12"},
{"pptm","application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
{"potm","application/vnd.ms-powerpoint.template.macroEnabled.12"},
{"ppsm","application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
{"ps", "application/postscript"},
{"qt", "video/quicktime"},
{"qti", "image/x-quicktime"},
{"qtif", "image/x-quicktime"},
{"ra", "audio/x-pn-realaudio"},
{"ram", "audio/x-pn-realaudio"},
{"ras", "image/x-cmu-raster"},
{"rdf", "application/rdf+xml"},
{"rgb", "image/x-rgb"},
{"rm", "application/vnd.rn-realmedia"},
{"roff", "application/x-troff"},
{"rtf", "text/rtf"},
{"rtx", "text/richtext"},
{"sgm", "text/sgml"},
{"sgml", "text/sgml"},
{"sh", "application/x-sh"},
{"shar", "application/x-shar"},
{"silo", "model/mesh"},
{"sit", "application/x-stuffit"},
{"skd", "application/x-koan"},
{"skm", "application/x-koan"},
{"skp", "application/x-koan"},
{"skt", "application/x-koan"},
{"smi", "application/smil"},
{"smil", "application/smil"},
{"snd", "audio/basic"},
{"so", "application/octet-stream"},
{"spl", "application/x-futuresplash"},
{"src", "application/x-wais-source"},
{"sv4cpio", "application/x-sv4cpio"},
{"sv4crc", "application/x-sv4crc"},
{"svg", "image/svg+xml"},
{"swf", "application/x-shockwave-flash"},
{"t", "application/x-troff"},
{"tar", "application/x-tar"},
{"tcl", "application/x-tcl"},
{"tex", "application/x-tex"},
{"texi", "application/x-texinfo"},
{"texinfo", "application/x-texinfo"},
{"tif", "image/tiff"},
{"tiff", "image/tiff"},
{"tr", "application/x-troff"},
{"tsv", "text/tab-separated-values"},
{"txt", "text/plain"},
{"ustar", "application/x-ustar"},
{"vcd", "application/x-cdlink"},
{"vrml", "model/vrml"},
{"vxml", "application/voicexml+xml"},
{"wav", "audio/x-wav"},
{"wbmp", "image/vnd.wap.wbmp"},
{"wbmxl", "application/vnd.wap.wbxml"},
{"wml", "text/vnd.wap.wml"},
{"wmlc", "application/vnd.wap.wmlc"},
{"wmls", "text/vnd.wap.wmlscript"},
{"wmlsc", "application/vnd.wap.wmlscriptc"},
{"wrl", "model/vrml"},
{"xbm", "image/x-xbitmap"},
{"xht", "application/xhtml+xml"},
{"xhtml", "application/xhtml+xml"},
{"xls", "application/vnd.ms-excel"},
{"xml", "application/xml"},
{"xpm", "image/x-xpixmap"},
{"xsl", "application/xml"},
{"xlsx","application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
{"xltx","application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
{"xlsm","application/vnd.ms-excel.sheet.macroEnabled.12"},
{"xltm","application/vnd.ms-excel.template.macroEnabled.12"},
{"xlam","application/vnd.ms-excel.addin.macroEnabled.12"},
{"xlsb","application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
{"xslt", "application/xslt+xml"},
{"xul", "application/vnd.mozilla.xul+xml"},
{"xwd", "image/x-xwindowdump"},
{"xyz", "chemical/x-xyz"},
{"zip", "application/zip"}
};
}
}
Je suis tombé sur le même problème et j'ai finalement opté pour ma propre version de la solution de Kirk Baucom, trouvé ici.
Il me semble que c'est une opportunité pour quelqu'un d'écrire un service de recherche en ligne.
Quoi qu'il en soit, j'espère que cela aide.
Si quelqu'un était partant, il pourrait porter l'excellent module Perl. Type de fichier à .NET.Dans le code se trouve un ensemble de recherches de nombres magiques d'en-tête de fichier pour chaque type de fichier ou correspondance d'expression régulière.
Voici une bibliothèque de détection de type de fichier .NET http://filetypedetective.codeplex.com/ mais il ne détecte pour le moment qu'un petit nombre de fichiers.
Cette réponse est une copie de la réponse de l'auteur (Richard Gourlay), mais améliorée pour résoudre les problèmes sur IIS 8 / win2012 (où la fonction provoquerait le crash du pool d'applications), basée sur le commentaire de Rohland pointant vers http://www.pinvoke.net/default.aspx/urlmon.findmimefromdata
using System.Runtime.InteropServices;
...
public static string GetMimeFromFile(string filename)
{
if (!File.Exists(filename))
throw new FileNotFoundException(filename + " not found");
const int maxContent = 256;
var buffer = new byte[maxContent];
using (var fs = new FileStream(filename, FileMode.Open))
{
if (fs.Length >= maxContent)
fs.Read(buffer, 0, maxContent);
else
fs.Read(buffer, 0, (int) fs.Length);
}
var mimeTypePtr = IntPtr.Zero;
try
{
var result = FindMimeFromData(IntPtr.Zero, null, buffer, maxContent, null, 0, out mimeTypePtr, 0);
if (result != 0)
{
Marshal.FreeCoTaskMem(mimeTypePtr);
throw Marshal.GetExceptionForHR(result);
}
var mime = Marshal.PtrToStringUni(mimeTypePtr);
Marshal.FreeCoTaskMem(mimeTypePtr);
return mime;
}
catch (Exception e)
{
if (mimeTypePtr != IntPtr.Zero)
{
Marshal.FreeCoTaskMem(mimeTypePtr);
}
return "unknown/unknown";
}
}
[DllImport("urlmon.dll", CharSet = CharSet.Unicode, ExactSpelling = true, SetLastError = false)]
private static extern int FindMimeFromData(IntPtr pBC,
[MarshalAs(UnmanagedType.LPWStr)] string pwzUrl,
[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.I1, SizeParamIndex = 3)] byte[] pBuffer,
int cbSize,
[MarshalAs(UnmanagedType.LPWStr)] string pwzMimeProposed,
int dwMimeFlags,
out IntPtr ppwzMimeOut,
int dwReserved);
@Steve Morgan et @Richard Gourlay c'est une excellente solution, merci pour cela.Un petit inconvénient est que lorsque le nombre d'octets dans un fichier est de 255 ou moins, le type MIME donnera parfois "application/octet-stream", ce qui est légèrement inexact pour les fichiers qui devraient produire "text/plain".J'ai mis à jour votre méthode d'origine pour tenir compte de cette situation comme suit :
Si le nombre d'octets dans le fichier est inférieur ou égal à 255 et que le type MIME déduit est "application/octet-stream", alors créez un nouveau tableau d'octets composé des octets du fichier d'origine répétés n fois jusqu'à ce que le nombre total soit atteint. d'octets est >= 256.Ensuite, revérifiez le type MIME sur ce nouveau tableau d'octets.
Méthode modifiée :
Imports System.Runtime.InteropServices
<DllImport("urlmon.dll", CharSet:=CharSet.Auto)> _
Private Shared Function FindMimeFromData(pBC As System.UInt32, <MarshalAs(UnmanagedType.LPStr)> pwzUrl As System.String, <MarshalAs(UnmanagedType.LPArray)> pBuffer As Byte(), cbSize As System.UInt32, <MarshalAs(UnmanagedType.LPStr)> pwzMimeProposed As System.String, dwMimeFlags As System.UInt32, _
ByRef ppwzMimeOut As System.UInt32, dwReserverd As System.UInt32) As System.UInt32
End Function
Private Function GetMimeType(ByVal f As FileInfo) As String
'See http://stackoverflow.com/questions/58510/using-net-how-can-you-find-the-mime-type-of-a-file-based-on-the-file-signature
Dim returnValue As String = ""
Dim fileStream As FileStream = Nothing
Dim fileStreamLength As Long = 0
Dim fileStreamIsLessThanBByteSize As Boolean = False
Const byteSize As Integer = 255
Const bbyteSize As Integer = byteSize + 1
Const ambiguousMimeType As String = "application/octet-stream"
Const unknownMimeType As String = "unknown/unknown"
Dim buffer As Byte() = New Byte(byteSize) {}
Dim fnGetMimeTypeValue As New Func(Of Byte(), Integer, String)(
Function(_buffer As Byte(), _bbyteSize As Integer) As String
Dim _returnValue As String = ""
Dim mimeType As UInt32 = 0
FindMimeFromData(0, Nothing, _buffer, _bbyteSize, Nothing, 0, mimeType, 0)
Dim mimeTypePtr As IntPtr = New IntPtr(mimeType)
_returnValue = Marshal.PtrToStringUni(mimeTypePtr)
Marshal.FreeCoTaskMem(mimeTypePtr)
Return _returnValue
End Function)
If (f.Exists()) Then
Try
fileStream = New FileStream(f.FullName(), FileMode.Open, FileAccess.Read, FileShare.ReadWrite)
fileStreamLength = fileStream.Length()
If (fileStreamLength >= bbyteSize) Then
fileStream.Read(buffer, 0, bbyteSize)
Else
fileStreamIsLessThanBByteSize = True
fileStream.Read(buffer, 0, CInt(fileStreamLength))
End If
returnValue = fnGetMimeTypeValue(buffer, bbyteSize)
If (returnValue.Equals(ambiguousMimeType, StringComparison.OrdinalIgnoreCase) AndAlso fileStreamIsLessThanBByteSize AndAlso fileStreamLength > 0) Then
'Duplicate the stream content until the stream length is >= bbyteSize to get a more deterministic mime type analysis.
Dim currentBuffer As Byte() = buffer.Take(fileStreamLength).ToArray()
Dim repeatCount As Integer = Math.Floor((bbyteSize / fileStreamLength) + 1)
Dim bBufferList As List(Of Byte) = New List(Of Byte)
While (repeatCount > 0)
bBufferList.AddRange(currentBuffer)
repeatCount -= 1
End While
Dim bbuffer As Byte() = bBufferList.Take(bbyteSize).ToArray()
returnValue = fnGetMimeTypeValue(bbuffer, bbyteSize)
End If
Catch ex As Exception
returnValue = unknownMimeType
Finally
If (fileStream IsNot Nothing) Then fileStream.Close()
End Try
End If
Return returnValue
End Function
IIS 7 ou plus
Utilisez ce code, mais vous devez être l'administrateur du serveur
public bool CheckMimeMapExtension(string fileExtension)
{
try
{
using (
ServerManager serverManager = new ServerManager())
{
// connects to default app.config
var config = serverManager.GetApplicationHostConfiguration();
var staticContent = config.GetSection("system.webServer/staticContent");
var mimeMap = staticContent.GetCollection();
foreach (var mimeType in mimeMap)
{
if (((String)mimeType["fileExtension"]).Equals(fileExtension, StringComparison.OrdinalIgnoreCase))
return true;
}
}
return false;
}
catch (Exception ex)
{
Console.WriteLine("An exception has occurred: \n{0}", ex.Message);
Console.Read();
}
return false;
}
Lorsque vous travaillez avec le rôle Web Windows Azure ou tout autre hôte qui exécute votre application en confiance limitée, n'oubliez pas que vous ne serez pas autorisé à accéder au registre ou au code non géré.Approche hybride - la combinaison de try-catch-for-registry et de dictionnaire en mémoire semble être une bonne solution qui contient un peu de tout.
J'utilise ce code pour le faire :
public class DefaultMimeResolver : IMimeResolver
{
private readonly IFileRepository _fileRepository;
public DefaultMimeResolver(IFileRepository fileRepository)
{
_fileRepository = fileRepository;
}
[DllImport(@"urlmon.dll", CharSet = CharSet.Auto)]
private static extern System.UInt32 FindMimeFromData(
System.UInt32 pBC, [MarshalAs(UnmanagedType.LPStr)] System.String pwzUrl,
[MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer,
System.UInt32 cbSize,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzMimeProposed,
System.UInt32 dwMimeFlags,
out System.UInt32 ppwzMimeOut,
System.UInt32 dwReserverd);
public string GetMimeTypeFromFileExtension(string fileExtension)
{
if (string.IsNullOrEmpty(fileExtension))
{
throw new ArgumentNullException("fileExtension");
}
string mimeType = GetMimeTypeFromList(fileExtension);
if (String.IsNullOrEmpty(mimeType))
{
mimeType = GetMimeTypeFromRegistry(fileExtension);
}
return mimeType;
}
public string GetMimeTypeFromFile(string filePath)
{
if (string.IsNullOrEmpty(filePath))
{
throw new ArgumentNullException("filePath");
}
if (!File.Exists(filePath))
{
throw new FileNotFoundException("File not found : ", filePath);
}
string mimeType = GetMimeTypeFromList(Path.GetExtension(filePath).ToLower());
if (String.IsNullOrEmpty(mimeType))
{
mimeType = GetMimeTypeFromRegistry(Path.GetExtension(filePath).ToLower());
if (String.IsNullOrEmpty(mimeType))
{
mimeType = GetMimeTypeFromFileInternal(filePath);
}
}
return mimeType;
}
private string GetMimeTypeFromList(string fileExtension)
{
string mimeType = null;
if (fileExtension.StartsWith("."))
{
fileExtension = fileExtension.TrimStart('.');
}
if (!String.IsNullOrEmpty(fileExtension) && _mimeTypes.ContainsKey(fileExtension))
{
mimeType = _mimeTypes[fileExtension];
}
return mimeType;
}
private string GetMimeTypeFromRegistry(string fileExtension)
{
string mimeType = null;
try
{
RegistryKey key = Registry.ClassesRoot.OpenSubKey(fileExtension);
if (key != null && key.GetValue("Content Type") != null)
{
mimeType = key.GetValue("Content Type").ToString();
}
}
catch (Exception)
{
// Empty. When this code is running in limited mode accessing registry is not allowed.
}
return mimeType;
}
private string GetMimeTypeFromFileInternal(string filePath)
{
string mimeType = null;
if (!File.Exists(filePath))
{
return null;
}
byte[] byteBuffer = new byte[256];
using (FileStream fileStream = _fileRepository.Get(filePath))
{
if (fileStream.Length >= 256)
{
fileStream.Read(byteBuffer, 0, 256);
}
else
{
fileStream.Read(byteBuffer, 0, (int)fileStream.Length);
}
}
try
{
UInt32 MimeTypeNum;
FindMimeFromData(0, null, byteBuffer, 256, null, 0, out MimeTypeNum, 0);
IntPtr mimeTypePtr = new IntPtr(MimeTypeNum);
string mimeTypeFromFile = Marshal.PtrToStringUni(mimeTypePtr);
Marshal.FreeCoTaskMem(mimeTypePtr);
if (!String.IsNullOrEmpty(mimeTypeFromFile) && mimeTypeFromFile != "text/plain" && mimeTypeFromFile != "application/octet-stream")
{
mimeType = mimeTypeFromFile;
}
}
catch
{
// Empty.
}
return mimeType;
}
private readonly Dictionary<string, string> _mimeTypes = new Dictionary<string, string>
{
{"ai", "application/postscript"},
{"aif", "audio/x-aiff"},
{"aifc", "audio/x-aiff"},
{"aiff", "audio/x-aiff"},
{"asc", "text/plain"},
{"atom", "application/atom+xml"},
{"au", "audio/basic"},
{"avi", "video/x-msvideo"},
{"bcpio", "application/x-bcpio"},
{"bin", "application/octet-stream"},
{"bmp", "image/bmp"},
{"cdf", "application/x-netcdf"},
{"cgm", "image/cgm"},
{"class", "application/octet-stream"},
{"cpio", "application/x-cpio"},
{"cpt", "application/mac-compactpro"},
{"csh", "application/x-csh"},
{"css", "text/css"},
{"dcr", "application/x-director"},
{"dif", "video/x-dv"},
{"dir", "application/x-director"},
{"djv", "image/vnd.djvu"},
{"djvu", "image/vnd.djvu"},
{"dll", "application/octet-stream"},
{"dmg", "application/octet-stream"},
{"dms", "application/octet-stream"},
{"doc", "application/msword"},
{"docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
{"dotx", "application/vnd.openxmlformats-officedocument.wordprocessingml.template"},
{"docm", "application/vnd.ms-word.document.macroEnabled.12"},
{"dotm", "application/vnd.ms-word.template.macroEnabled.12"},
{"dtd", "application/xml-dtd"},
{"dv", "video/x-dv"},
{"dvi", "application/x-dvi"},
{"dxr", "application/x-director"},
{"eps", "application/postscript"},
{"etx", "text/x-setext"},
{"exe", "application/octet-stream"},
{"ez", "application/andrew-inset"},
{"gif", "image/gif"},
{"gram", "application/srgs"},
{"grxml", "application/srgs+xml"},
{"gtar", "application/x-gtar"},
{"hdf", "application/x-hdf"},
{"hqx", "application/mac-binhex40"},
{"htc", "text/x-component"},
{"htm", "text/html"},
{"html", "text/html"},
{"ice", "x-conference/x-cooltalk"},
{"ico", "image/x-icon"},
{"ics", "text/calendar"},
{"ief", "image/ief"},
{"ifb", "text/calendar"},
{"iges", "model/iges"},
{"igs", "model/iges"},
{"jnlp", "application/x-java-jnlp-file"},
{"jp2", "image/jp2"},
{"jpe", "image/jpeg"},
{"jpeg", "image/jpeg"},
{"jpg", "image/jpeg"},
{"js", "application/x-javascript"},
{"kar", "audio/midi"},
{"latex", "application/x-latex"},
{"lha", "application/octet-stream"},
{"lzh", "application/octet-stream"},
{"m3u", "audio/x-mpegurl"},
{"m4a", "audio/mp4a-latm"},
{"m4b", "audio/mp4a-latm"},
{"m4p", "audio/mp4a-latm"},
{"m4u", "video/vnd.mpegurl"},
{"m4v", "video/x-m4v"},
{"mac", "image/x-macpaint"},
{"man", "application/x-troff-man"},
{"mathml", "application/mathml+xml"},
{"me", "application/x-troff-me"},
{"mesh", "model/mesh"},
{"mid", "audio/midi"},
{"midi", "audio/midi"},
{"mif", "application/vnd.mif"},
{"mov", "video/quicktime"},
{"movie", "video/x-sgi-movie"},
{"mp2", "audio/mpeg"},
{"mp3", "audio/mpeg"},
{"mp4", "video/mp4"},
{"mpe", "video/mpeg"},
{"mpeg", "video/mpeg"},
{"mpg", "video/mpeg"},
{"mpga", "audio/mpeg"},
{"ms", "application/x-troff-ms"},
{"msh", "model/mesh"},
{"mxu", "video/vnd.mpegurl"},
{"nc", "application/x-netcdf"},
{"oda", "application/oda"},
{"ogg", "application/ogg"},
{"pbm", "image/x-portable-bitmap"},
{"pct", "image/pict"},
{"pdb", "chemical/x-pdb"},
{"pdf", "application/pdf"},
{"pgm", "image/x-portable-graymap"},
{"pgn", "application/x-chess-pgn"},
{"pic", "image/pict"},
{"pict", "image/pict"},
{"png", "image/png"},
{"pnm", "image/x-portable-anymap"},
{"pnt", "image/x-macpaint"},
{"pntg", "image/x-macpaint"},
{"ppm", "image/x-portable-pixmap"},
{"ppt", "application/vnd.ms-powerpoint"},
{"pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
{"potx", "application/vnd.openxmlformats-officedocument.presentationml.template"},
{"ppsx", "application/vnd.openxmlformats-officedocument.presentationml.slideshow"},
{"ppam", "application/vnd.ms-powerpoint.addin.macroEnabled.12"},
{"pptm", "application/vnd.ms-powerpoint.presentation.macroEnabled.12"},
{"potm", "application/vnd.ms-powerpoint.template.macroEnabled.12"},
{"ppsm", "application/vnd.ms-powerpoint.slideshow.macroEnabled.12"},
{"ps", "application/postscript"},
{"qt", "video/quicktime"},
{"qti", "image/x-quicktime"},
{"qtif", "image/x-quicktime"},
{"ra", "audio/x-pn-realaudio"},
{"ram", "audio/x-pn-realaudio"},
{"ras", "image/x-cmu-raster"},
{"rdf", "application/rdf+xml"},
{"rgb", "image/x-rgb"},
{"rm", "application/vnd.rn-realmedia"},
{"roff", "application/x-troff"},
{"rtf", "text/rtf"},
{"rtx", "text/richtext"},
{"sgm", "text/sgml"},
{"sgml", "text/sgml"},
{"sh", "application/x-sh"},
{"shar", "application/x-shar"},
{"silo", "model/mesh"},
{"sit", "application/x-stuffit"},
{"skd", "application/x-koan"},
{"skm", "application/x-koan"},
{"skp", "application/x-koan"},
{"skt", "application/x-koan"},
{"smi", "application/smil"},
{"smil", "application/smil"},
{"snd", "audio/basic"},
{"so", "application/octet-stream"},
{"spl", "application/x-futuresplash"},
{"src", "application/x-wais-source"},
{"sv4cpio", "application/x-sv4cpio"},
{"sv4crc", "application/x-sv4crc"},
{"svg", "image/svg+xml"},
{"swf", "application/x-shockwave-flash"},
{"t", "application/x-troff"},
{"tar", "application/x-tar"},
{"tcl", "application/x-tcl"},
{"tex", "application/x-tex"},
{"texi", "application/x-texinfo"},
{"texinfo", "application/x-texinfo"},
{"tif", "image/tiff"},
{"tiff", "image/tiff"},
{"tr", "application/x-troff"},
{"tsv", "text/tab-separated-values"},
{"txt", "text/plain"},
{"ustar", "application/x-ustar"},
{"vcd", "application/x-cdlink"},
{"vrml", "model/vrml"},
{"vxml", "application/voicexml+xml"},
{"wav", "audio/x-wav"},
{"wbmp", "image/vnd.wap.wbmp"},
{"wbmxl", "application/vnd.wap.wbxml"},
{"wml", "text/vnd.wap.wml"},
{"wmlc", "application/vnd.wap.wmlc"},
{"wmls", "text/vnd.wap.wmlscript"},
{"wmlsc", "application/vnd.wap.wmlscriptc"},
{"wrl", "model/vrml"},
{"xbm", "image/x-xbitmap"},
{"xht", "application/xhtml+xml"},
{"xhtml", "application/xhtml+xml"},
{"xls", "application/vnd.ms-excel"},
{"xml", "application/xml"},
{"xpm", "image/x-xpixmap"},
{"xsl", "application/xml"},
{"xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
{"xltx", "application/vnd.openxmlformats-officedocument.spreadsheetml.template"},
{"xlsm", "application/vnd.ms-excel.sheet.macroEnabled.12"},
{"xltm", "application/vnd.ms-excel.template.macroEnabled.12"},
{"xlam", "application/vnd.ms-excel.addin.macroEnabled.12"},
{"xlsb", "application/vnd.ms-excel.sheet.binary.macroEnabled.12"},
{"xslt", "application/xslt+xml"},
{"xul", "application/vnd.mozilla.xul+xml"},
{"xwd", "image/x-xwindowdump"},
{"xyz", "chemical/x-xyz"},
{"zip", "application/zip"}
};
}
J'ai fini par utiliser Winista MimeDetector de Netomatix.Les sources peuvent être téléchargées gratuitement après avoir créé un compte : http://www.netomatix.com/Products/DocumentManagement/MimeDetector.aspx
MimeTypes g_MimeTypes = new MimeTypes("mime-types.xml");
sbyte [] fileData = null;
using (System.IO.FileStream srcFile = new System.IO.FileStream(strFile, System.IO.FileMode.Open))
{
byte [] data = new byte[srcFile.Length];
srcFile.Read(data, 0, (Int32)srcFile.Length);
fileData = Winista.Mime.SupportUtil.ToSByteArray(data);
}
MimeType oMimeType = g_MimeTypes.GetMimeType(fileData);
Cela fait partie d'une autre question répondue ici : Alternative à la méthode FindMimeFromData dans Urlmon.dll, celle qui a plus de types MIMELa meilleure solution à ce problème à mon avis.
Détection Winista MIME avec URLMon téléchargez le projet ici :https://github.com/MeaningOfLights/MimeDetect
Supposons que quelqu'un renomme un exe avec une extension jpg, vous pouvez toujours déterminer le "vrai" format de fichier à l'aide de l'analyse binaire.Il ne détecte pas les swf ou les flv mais fait à peu près tous les autres formats bien connus + vous pouvez obtenir un éditeur hexadécimal et ajouter plus de fichiers qu'il peut détecter.
Magie des fichiers
Winista détecte le type MIME réel à l'aide d'un fichier XML "mime-type.xml" qui contient des informations sur les types de fichiers et les signatures utilisées pour identifier le type de contenu. Par exemple :
<!--
! Audio primary type
! -->
<mime-type name="audio/basic"
description="uLaw/AU Audio File">
<ext>au</ext><ext>snd</ext>
<magic offset="0" type="byte" value="2e736e64000000"/>
</mime-type>
<mime-type name="audio/midi"
description="Musical Instrument Digital Interface MIDI-sequention Sound">
<ext>mid</ext><ext>midi</ext><ext>kar</ext>
<magic offset="0" value="MThd"/>
</mime-type>
<mime-type name="audio/mpeg"
description="MPEG Audio Stream, Layer III">
<ext>mp3</ext><ext>mp2</ext><ext>mpga</ext>
<magic offset="0" value="ID3"/>
</mime-type>
Lorsque Winista ne parvient pas à détecter le format de fichier réel, j'ai recours à la méthode URLMon :
public class urlmonMimeDetect
{
[DllImport(@"urlmon.dll", CharSet = CharSet.Auto)]
private extern static System.UInt32 FindMimeFromData(
System.UInt32 pBC,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzUrl,
[MarshalAs(UnmanagedType.LPArray)] byte[] pBuffer,
System.UInt32 cbSize,
[MarshalAs(UnmanagedType.LPStr)] System.String pwzMimeProposed,
System.UInt32 dwMimeFlags,
out System.UInt32 ppwzMimeOut,
System.UInt32 dwReserverd
);
public string GetMimeFromFile(string filename)
{
if (!File.Exists(filename))
throw new FileNotFoundException(filename + " not found");
byte[] buffer = new byte[256];
using (FileStream fs = new FileStream(filename, FileMode.Open, FileAccess.Read))
{
if (fs.Length >= 256)
fs.Read(buffer, 0, 256);
else
fs.Read(buffer, 0, (int)fs.Length);
}
try
{
System.UInt32 mimetype;
FindMimeFromData(0, null, buffer, 256, null, 0, out mimetype, 0);
System.IntPtr mimeTypePtr = new IntPtr(mimetype);
string mime = Marshal.PtrToStringUni(mimeTypePtr);
Marshal.FreeCoTaskMem(mimeTypePtr);
return mime;
}
catch (Exception e)
{
return "unknown/unknown";
}
}
}
Depuis la méthode Winista, je me rabats sur URLMon ici :
public MimeType GetMimeTypeFromFile(string filePath)
{
sbyte[] fileData = null;
using (FileStream srcFile = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
byte[] data = new byte[srcFile.Length];
srcFile.Read(data, 0, (Int32)srcFile.Length);
fileData = Winista.Mime.SupportUtil.ToSByteArray(data);
}
MimeType oMimeType = GetMimeType(fileData);
if (oMimeType != null) return oMimeType;
//We haven't found the file using Magic (eg a text/plain file)
//so instead use URLMon to try and get the files format
Winista.MimeDetect.URLMONMimeDetect.urlmonMimeDetect urlmonMimeDetect = new Winista.MimeDetect.URLMONMimeDetect.urlmonMimeDetect();
string urlmonMimeType = urlmonMimeDetect.GetMimeFromFile(filePath);
if (!string.IsNullOrEmpty(urlmonMimeType))
{
foreach (MimeType mimeType in types)
{
if (mimeType.Name == urlmonMimeType)
{
return mimeType;
}
}
}
return oMimeType;
}
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