I have a web server based on TIdHTTPServer. It is built in Delphi Sydney. From a webpage I'm receiving following multipart/form-data post stream:
-----------------------------16857441221270830881532229640
Content-Disposition: form-data; name="d"
83AAAFUaVVs4Q07z
-----------------------------16857441221270830881532229640
Content-Disposition: form-data; name="dir"
Upload
-----------------------------16857441221270830881532229640
Content-Disposition: form-data; name="file_name"; filename="česká tečka.png"
Content-Type: image/png
PNG_DATA
-----------------------------16857441221270830881532229640--
Problem is that text parts are not received correctly. I read the Indy MIME decoding of Multipart/Form-Data Requests returns trailing CR/LF and changed transfer encoding to 8bit which helps to receive file correctly, but received file name is still wrong (dir should be Upload and filename should be česká tečka.png).
d=83AAAFUaVVs4Q07z
dir=UploadW
??esk?? te??ka.png 75
To demonstrate the issue I simplified my code to a console app (please note that the MIME.txt file contains the same as is in post stream above):
program MIMEMultiPartTest;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.Classes, System.SysUtils,
IdGlobal, IdCoder, IdMessage, IdMessageCoder, IdGlobalProtocols, IdCoderMIME, IdMessageCoderMIME,
IdCoderQuotedPrintable, IdCoderBinHex4;
procedure ProcessAttachmentPart(var Decoder: TIdMessageDecoder; var MsgEnd: Boolean);
var
MS: TMemoryStream;
Name: string;
Value: string;
NewDecoder: TIdMessageDecoder;
begin
MS := TMemoryStream.Create;
try
// http://stackoverflow.com/questions/27257577/indy-mime-decoding-of-multipart-form-data-requests-returns-trailing-cr-lf
TIdMessageDecoderMIME(Decoder).Headers.Values['Content-Transfer-Encoding'] := '8bit';
TIdMessageDecoderMIME(Decoder).BodyEncoded := False;
NewDecoder := Decoder.ReadBody(MS, MsgEnd);
MS.Position := 0; // nutne?
if Decoder.Filename <> EmptyStr then // je to atachment
begin
try
Writeln(Decoder.Filename + ' ' + IntToStr(MS.Size));
except
FreeAndNil(NewDecoder);
Writeln('Error processing MIME');
end;
end
else // je to parametr
begin
Name := ExtractHeaderSubItem(Decoder.Headers.Text, 'name', QuoteHTTP);
if Name <> EmptyStr then
begin
Value := string(PAnsiChar(MS.Memory));
try
Writeln(Name + '=' + Value);
except
FreeAndNil(NewDecoder);
Writeln('Error processing MIME');
end;
end;
end;
Decoder.Free;
Decoder := NewDecoder;
finally
MS.Free;
end;
end;
function ProcessMultiPart(const ContentType: string; Stream: TStream): Boolean;
var
Boundary: string;
BoundaryStart: string;
BoundaryEnd: string;
Decoder: TIdMessageDecoder;
Line: string;
BoundaryFound: Boolean;
IsStartBoundary: Boolean;
MsgEnd: Boolean;
begin
Result := False;
Boundary := ExtractHeaderSubItem('multipart/form-data; boundary=---------------------------16857441221270830881532229640', 'boundary', QuoteHTTP);
if Boundary <> EmptyStr then
begin
BoundaryStart := '--' + Boundary;
BoundaryEnd := BoundaryStart + '--';
Decoder := TIdMessageDecoderMIME.Create(nil);
try
TIdMessageDecoderMIME(Decoder).MIMEBoundary := Boundary;
Decoder.SourceStream := Stream;
Decoder.FreeSourceStream := False;
BoundaryFound := False;
IsStartBoundary := False;
repeat
Line := ReadLnFromStream(Stream, -1, True);
if Line = BoundaryStart then
begin
BoundaryFound := True;
IsStartBoundary := True;
end
else
begin
if Line = BoundaryEnd then
BoundaryFound := True;
end;
until BoundaryFound;
if BoundaryFound and IsStartBoundary then
begin
MsgEnd := False;
repeat
TIdMessageDecoderMIME(Decoder).MIMEBoundary := Boundary;
Decoder.SourceStream := Stream;
Decoder.FreeSourceStream := False;
Decoder.ReadHeader;
case Decoder.PartType of
mcptText,
mcptAttachment:
begin
ProcessAttachmentPart(Decoder, MsgEnd);
end;
mcptIgnore:
begin
Decoder.Free;
Decoder := TIdMessageDecoderMIME.Create(nil);
end;
mcptEOF:
begin
Decoder.Free;
MsgEnd := True;
end;
end;
until (Decoder = nil) or MsgEnd;
Result := True;
end
finally
Decoder.Free;
end;
end;
end;
var
Stream: TMemoryStream;
begin
Stream := TMemoryStream.Create;
try
Stream.LoadFromFile('MIME.txt');
ProcessMultiPart('multipart/form-data; boundary=---------------------------16857441221270830881532229640', Stream);
finally
Stream.Free;
end;
Readln;
end.
Could someone help me what is wrong with my code? Thank you.
