Neuron®
The Neuron® is the basis for the creation of open and secure federated networks for smart societies.
Loading...
Searching...
No Matches
FormDataDecoder.cs
1using System;
2using System.Collections.Generic;
3using System.IO;
4using System.Text;
5using System.Threading.Tasks;
6using Waher.Content.Text;
7using Waher.Runtime.Inventory;
8
9namespace Waher.Content.Multipart
10{
16 public class FormDataDecoder : IContentDecoder
17 {
21 public const string ContentType = "multipart/form-data";
22
28 public FormDataDecoder()
29 {
30 }
31
35 public string[] ContentTypes => new string[] { ContentType };
36
40 public string[] FileExtensions => new string[] { "formdata" };
41
48 public bool Decodes(string ContentType, out Grade Grade)
49 {
50 if (ContentType == FormDataDecoder.ContentType)
51 {
52 Grade = Grade.Excellent;
53 return true;
54 }
55 else
56 {
57 Grade = Grade.NotAtAll;
58 return false;
59 }
60 }
61
72 public async Task<object> DecodeAsync(string ContentType, byte[] Data, Encoding Encoding, KeyValuePair<string, string>[] Fields, Uri BaseUri)
73 {
74 Dictionary<string, object> Form = new Dictionary<string, object>();
75
76 await Decode(Data, Fields, Form, null, BaseUri);
77
78 return Form;
79 }
80
89 public static async Task Decode(byte[] Data, KeyValuePair<string, string>[] Fields, Dictionary<string, object> Form,
90 List<EmbeddedContent> List, Uri BaseUri)
91 {
92 string Boundary = null;
93
94 if (!(Fields is null))
95 {
96 foreach (KeyValuePair<string, string> P in Fields)
97 {
98 if (string.Compare(P.Key, "BOUNDARY", true) == 0)
99 {
100 Boundary = P.Value;
101 break;
102 }
103 }
104 }
105
106 if (string.IsNullOrEmpty(Boundary))
107 throw new Exception("No boundary defined.");
108
109 byte[] BoundaryBin = Encoding.ASCII.GetBytes(Boundary);
110 int Start = 0;
111 int i = 0;
112 int c = Data.Length;
113 int d = BoundaryBin.Length;
114 int j;
115 int Max = c - d;
116
117 while (i < Max)
118 {
119 for (j = 0; j < d; j++)
120 {
121 if (Data[i + j] != BoundaryBin[j])
122 break;
123 }
124
125 if (j == d)
126 {
127 await AddPart(Data, Start, i, false, Form, List, BaseUri);
128
129 i += d;
130 while (i < c && Data[i] <= 32)
131 i++;
132
133 Start = i;
134 }
135 else
136 i++;
137 }
138
139 if (Start < c)
140 await AddPart(Data, Start, c, true, Form, List, BaseUri);
141 }
142
143 private static async Task AddPart(byte[] Data, int Start, int i, bool Last,
144 Dictionary<string, object> Form, List<EmbeddedContent> List, Uri BaseUri)
145 {
146 int j, k, l, m;
147 int Max = i - 3;
148
149 for (j = Start; j < Max; j++)
150 {
151 if (Data[j] == '\r' && Data[j + 1] == '\n' && Data[j + 2] == '\r' && Data[j + 3] == '\n')
152 break;
153 }
154
155 if (j == Start)
156 return;
157
158 if (j < i)
159 {
160 k = 0;
161 if (i >= 2 && Data[i - 1] == '-' && Data[i - 2] == '-')
162 {
163 k = 2;
164
165 if (i >= 4 && Data[i - 1 - k] == '\n' && Data[i - 2 - k] == '\r')
166 k += 2;
167 }
168
169 int NrBytes = i - j - 4 - k;
170 if (NrBytes < 0 || (NrBytes == 0 && Last))
171 return;
172
173 string Header = Encoding.ASCII.GetString(Data, Start, j - Start);
174 string Key, Value;
175 byte[] Data2 = new byte[NrBytes];
176 EmbeddedContent EmbeddedContent = new EmbeddedContent()
177 {
178 ContentType = PlainTextCodec.DefaultContentType,
179 Raw = Data2
180 };
181
182 Array.Copy(Data, j + 4, Data2, 0, NrBytes);
183
184 string[] Rows = Header.Split(CommonTypes.CRLF);
185 l = Rows.Length;
186 m = -1;
187
188 for (j = 0; j < l; j++)
189 {
190 Key = Rows[j];
191 if (!string.IsNullOrEmpty(Key))
192 {
193 if (char.IsWhiteSpace(Key[0]) && m >= 0)
194 {
195 Rows[m] += Key;
196 Rows[j] = string.Empty;
197 }
198 else
199 m = j;
200 }
201 }
202
203 foreach (string Row in Rows)
204 {
205 j = Row.IndexOf(':');
206 if (j < 0)
207 continue;
208
209 Key = Row.Substring(0, j).Trim();
210 Value = Row.Substring(j + 1).Trim();
211
212 switch (Key.ToUpper())
213 {
214 case "CONTENT-TYPE":
215 EmbeddedContent.ContentType = Value;
216 j = Value.IndexOf(';');
217 if (j >= 0)
218 {
219 ParseContentFields(Value.Substring(j + 1).Trim(), EmbeddedContent);
220 Value = Value.Substring(0, j).Trim();
221 }
222 break;
223
224 case "CONTENT-DISPOSITION":
225 j = Value.IndexOf(';');
226 if (j >= 0)
227 {
228 ParseContentFields(Value.Substring(j + 1).Trim(), EmbeddedContent);
229 Value = Value.Substring(0, j).Trim();
230 }
231
232 switch (Value.ToUpper())
233 {
234 case "INLINE":
235 EmbeddedContent.Disposition = ContentDisposition.Inline;
236 break;
237
238 case "ATTACHMENT":
239 EmbeddedContent.Disposition = ContentDisposition.Attachment;
240 break;
241
242 case "FORM-DATA":
243 EmbeddedContent.Disposition = ContentDisposition.FormData;
244 break;
245 }
246 break;
247
248 case "CONTENT-TRANSFER-ENCODING":
249 EmbeddedContent.TransferEncoding = Value;
250 break;
251
252 case "CONTENT-ID":
253 EmbeddedContent.ID = Value;
254 break;
255
256 case "CONTENT-DESCRIPTION":
257 EmbeddedContent.Description = Value;
258 break;
259 }
260 }
261
262 if (!string.IsNullOrEmpty(EmbeddedContent.TransferEncoding))
263 {
264 if (TryTransferDecode(Data2, EmbeddedContent.TransferEncoding, out Data2))
265 EmbeddedContent.TransferDecoded = Data2;
266 else
267 throw new Exception("Unrecognized Content-Transfer-Encoding: " + EmbeddedContent.TransferEncoding);
268 }
269
270 try
271 {
272 EmbeddedContent.Decoded = await InternetContent.DecodeAsync(EmbeddedContent.ContentType, Data2, BaseUri);
273 }
274 catch (Exception)
275 {
276 EmbeddedContent.Decoded = Data2;
277 }
278
279 if (!(Form is null))
280 {
281 Form[EmbeddedContent.Name] = EmbeddedContent.Decoded;
282 Form[EmbeddedContent.Name + "_Binary"] = Data2;
283
284 if (!string.IsNullOrEmpty(EmbeddedContent.ContentType))
285 Form[EmbeddedContent.Name + "_ContentType"] = EmbeddedContent.ContentType;
286
287 if (!string.IsNullOrEmpty(EmbeddedContent.FileName))
288 Form[EmbeddedContent.Name + "_FileName"] = EmbeddedContent.FileName;
289 }
290
291 List?.Add(EmbeddedContent);
292 }
293 }
294
295 private static void ParseContentFields(string s, EmbeddedContent EmbeddedContent)
296 {
297 foreach (KeyValuePair<string, string> Field in CommonTypes.ParseFieldValues(s))
298 {
299 switch (Field.Key.ToUpper())
300 {
301 case "NAME":
302 EmbeddedContent.Name = Field.Value;
303 break;
304
305 case "FILENAME":
306 EmbeddedContent.FileName = Field.Value;
307 break;
308
309 case "SIZE":
310 if (int.TryParse(Field.Value, out int i))
311 EmbeddedContent.Size = i;
312 break;
313
314 case "CREATION-DATE":
315 if (CommonTypes.TryParseRfc822(Field.Value, out DateTimeOffset DTO))
316 EmbeddedContent.CreationDate = DTO;
317 break;
318
319 case "MODIFICATION-DATE":
320 if (CommonTypes.TryParseRfc822(Field.Value, out DTO))
321 EmbeddedContent.ModificationDate = DTO;
322 break;
323 }
324 }
325 }
326
334 public static bool TryTransferDecode(byte[] Encoded, string TransferEncoding, out byte[] Decoded)
335 {
336 switch (TransferEncoding.ToUpper())
337 {
338 case "7BIT":
339 case "8BIT":
340 case "BINARY":
341 case "":
342 case null:
343 Decoded = Encoded;
344 return true;
345
346 case "BASE64":
347 string s = CommonTypes.GetString(Encoded, Encoding.ASCII);
348 Decoded = Convert.FromBase64String(s);
349 return true;
350
351 case "QUOTED-PRINTABLE":
352 MemoryStream ms = new MemoryStream();
353 byte b;
354 char ch;
355 int j, k;
356
357 for (j = 0, k = Encoded.Length; j < k; j++)
358 {
359 b = Encoded[j];
360
361 if (b == (byte)'=' && j + 2 < k)
362 {
363 ch = (char)Encoded[++j];
364
365 if (ch >= '0' && ch <= '9')
366 b = (byte)(ch - '0');
367 else if (ch >= 'a' && ch <= 'f')
368 b = (byte)(ch - 'a' + 10);
369 else if (ch >= 'A' && ch <= 'F')
370 b = (byte)(ch - 'A' + 10);
371 else if (ch == '\r')
372 {
373 if (Encoded[j + 1] == (byte)'\n')
374 j++;
375
376 continue;
377 }
378 else
379 {
380 ms.WriteByte((byte)'=');
381 ms.WriteByte((byte)ch);
382 continue;
383 }
384
385 b <<= 4;
386
387 ch = (char)Encoded[++j];
388
389 if (ch >= '0' && ch <= '9')
390 b |= (byte)(ch - '0');
391 else if (ch >= 'a' && ch <= 'f')
392 b |= (byte)(ch - 'a' + 10);
393 else if (ch >= 'A' && ch <= 'F')
394 b |= (byte)(ch - 'A' + 10);
395 }
396
397 ms.WriteByte(b);
398 }
399
400 Decoded = ms.ToArray();
401 ms.Dispose();
402 return true;
403
404 default:
405 Decoded = null;
406 return false;
407 }
408 }
409
416 public bool TryGetContentType(string FileExtension, out string ContentType)
417 {
418 if (string.Compare(FileExtension, "formdata", true) == 0)
419 {
420 ContentType = FormDataDecoder.ContentType;
421 return true;
422 }
423 else
424 {
425 ContentType = string.Empty;
426 return false;
427 }
428 }
429
436 public bool TryGetFileExtension(string ContentType, out string FileExtension)
437 {
438 switch (ContentType.ToLower())
439 {
440 case FormDataDecoder.ContentType:
441 FileExtension = "formdata";
442 return true;
443
444 default:
445 FileExtension = string.Empty;
446 return false;
447 }
448 }
449
455 public static async Task<KeyValuePair<byte[], string>> Encode(IEnumerable<EmbeddedContent> Content)
456 {
457 string Boundary = Guid.NewGuid().ToString();
458 string ContentType = FormDataDecoder.ContentType + "; boundary=\"" + Boundary + "\"";
459 return new KeyValuePair<byte[], string>(await Encode(Content, Boundary), ContentType);
460 }
461
468 public static async Task<byte[]> Encode(IEnumerable<EmbeddedContent> Content, string Boundary)
469 {
470 using (MemoryStream ms = new MemoryStream())
471 {
472 StringBuilder Header = new StringBuilder();
473 byte[] HeaderBin;
474
475 foreach (EmbeddedContent Alternative in Content)
476 {
477 await Alternative.AssertEncoded();
478
479 Header.Clear();
480 Header.Append("\r\n--");
481 Header.Append(Boundary);
482
483 if (!string.IsNullOrEmpty(Alternative.TransferEncoding))
484 {
485 Header.Append("\r\nContent-Transfer-Encoding: ");
486 Header.Append(Alternative.TransferEncoding);
487 }
488
489 Header.Append("\r\nContent-Type: ");
490 Header.Append(Alternative.ContentType);
491
492 if (!string.IsNullOrEmpty(Alternative.Name) && Alternative.Disposition != ContentDisposition.FormData)
493 {
494 Header.Append("; name=\"");
495 Header.Append(Alternative.Name.Replace("\"", "\\\""));
496 Header.Append("\"");
497 }
498
499 if (Alternative.Disposition != ContentDisposition.Unknown ||
500 !string.IsNullOrEmpty(Alternative.FileName))
501 {
502 Header.Append("\r\nContent-Disposition: ");
503
504 switch (Alternative.Disposition)
505 {
506 case ContentDisposition.FormData:
507 Header.Append("form-data");
508
509 if (!string.IsNullOrEmpty(Alternative.Name))
510 {
511 Header.Append("; name=\"");
512 Header.Append(Alternative.Name.Replace("\"", "\\\""));
513 Header.Append("\"");
514 }
515 break;
516
517 case ContentDisposition.Inline:
518 Header.Append("inline");
519 break;
520
521 case ContentDisposition.Attachment:
522 default:
523 Header.Append("attachment");
524 break;
525 }
526
527 if (!string.IsNullOrEmpty(Alternative.FileName))
528 {
529 Header.Append("; filename=\"");
530 Header.Append(Alternative.FileName.Replace("\"", "\\\""));
531 Header.Append("\"");
532 }
533 }
534
535 if (!string.IsNullOrEmpty(Alternative.ID))
536 {
537 Header.Append("\r\nContent-ID: ");
538 Header.Append(Alternative.ID);
539 }
540
541 if (!string.IsNullOrEmpty(Alternative.Description))
542 {
543 Header.Append("\r\nContent-Description: ");
544 Header.Append(Alternative.Description);
545 }
546
547 Header.Append("\r\n\r\n");
548
549 HeaderBin = Encoding.ASCII.GetBytes(Header.ToString());
550 ms.Write(HeaderBin, 0, HeaderBin.Length);
551 ms.Write(Alternative.Raw, 0, Alternative.Raw.Length);
552 }
553
554
555 Header.Clear();
556 Header.Append("\r\n--");
557 Header.Append(Boundary);
558 Header.Append("--");
559
560 HeaderBin = Encoding.ASCII.GetBytes(Header.ToString());
561 ms.Write(HeaderBin, 0, HeaderBin.Length);
562
563 return ms.ToArray();
564 }
565 }
566 }
567}
Waher.Content.CommonTypes
Helps with parsing of commong data types.
Definition: CommonTypes.cs:13
Waher.Content.CommonTypes.CRLF
static readonly char[] CRLF
Contains the CR LF character sequence.
Definition: CommonTypes.cs:17
Waher.Content.CommonTypes.ParseFieldValues
static KeyValuePair< string, string >[] ParseFieldValues(string Value)
Parses a set of comma or semicolon-separated field values, optionaly delimited by ' or " characters.
Definition: CommonTypes.cs:472
Waher.Content.CommonTypes.TryParseRfc822
static bool TryParseRfc822(string s, out DateTimeOffset Value)
Parses a date and time value encoded according to RFC 822, §5.
Definition: CommonTypes.cs:170
Waher.Content.CommonTypes.GetString
static string GetString(byte[] Data, Encoding DefaultEncoding)
Gets a string from its binary representation, taking any Byte Order Mark (BOM) into account.
Definition: CommonTypes.cs:1071
Waher.Content.InternetContent
Static class managing encoding and decoding of internet content.
Definition: InternetContent.cs:17
Waher.Content.InternetContent.DecodeAsync
static Task< object > DecodeAsync(string ContentType, byte[] Data, Encoding Encoding, KeyValuePair< string, string >[] Fields, Uri BaseUri)
Decodes an object.
Definition: InternetContent.cs:547
Waher.Content.Multipart.EmbeddedContent
Represents content embedded in other content.
Definition: EmbeddedContent.cs:38
Waher.Content.Multipart.EmbeddedContent.FileName
string FileName
Filename of embedded object.
Definition: EmbeddedContent.cs:84
Waher.Content.Multipart.EmbeddedContent.Disposition
ContentDisposition Disposition
Disposition of embedded object.
Definition: EmbeddedContent.cs:66
Waher.Content.Multipart.EmbeddedContent.Name
string Name
Name of embedded object.
Definition: EmbeddedContent.cs:75
Waher.Content.Multipart.EmbeddedContent.Description
string Description
Content-Description of embedded object, if defined.
Definition: EmbeddedContent.cs:142
Waher.Content.Multipart.EmbeddedContent.ContentType
string ContentType
Content-Type of embedded object.
Definition: EmbeddedContent.cs:57
Waher.Content.Multipart.EmbeddedContent.Raw
byte[] Raw
Raw, untrasnformed body of embedded object.
Definition: EmbeddedContent.cs:104
Waher.Content.Multipart.EmbeddedContent.TransferEncoding
string TransferEncoding
Content Transfer Encoding of embedded object, if defined. Affects how Raw is transformed into Transfe...
Definition: EmbeddedContent.cs:95
Waher.Content.Multipart.EmbeddedContent.ID
string ID
Content-ID of embedded object, if defined.
Definition: EmbeddedContent.cs:133
Waher.Content.Multipart.FormDataDecoder
Decoder of form data.
Definition: FormDataDecoder.cs:17
Waher.Content.Multipart.FormDataDecoder.TryGetContentType
bool TryGetContentType(string FileExtension, out string ContentType)
Tries to get the content type of an item, given its file extension.
Definition: FormDataDecoder.cs:416
Waher.Content.Multipart.FormDataDecoder.FileExtensions
string[] FileExtensions
Supported file extensions.
Definition: FormDataDecoder.cs:40
Waher.Content.Multipart.FormDataDecoder.TryGetFileExtension
bool TryGetFileExtension(string ContentType, out string FileExtension)
Tries to get the file extension of an item, given its Content-Type.
Definition: FormDataDecoder.cs:436
Waher.Content.Multipart.FormDataDecoder.FormDataDecoder
FormDataDecoder()
Decoder of form data.
Definition: FormDataDecoder.cs:28
Waher.Content.Multipart.FormDataDecoder.Decode
static async Task Decode(byte[] Data, KeyValuePair< string, string >[] Fields, Dictionary< string, object > Form, List< EmbeddedContent > List, Uri BaseUri)
Decodes a multipart object
Definition: FormDataDecoder.cs:89
Waher.Content.Multipart.FormDataDecoder.Decodes
bool Decodes(string ContentType, out Grade Grade)
If the decoder decodes an object with a given content type.
Definition: FormDataDecoder.cs:48
Waher.Content.Multipart.FormDataDecoder.Encode
static async Task< byte[]> Encode(IEnumerable< EmbeddedContent > Content, string Boundary)
Encodes multi-part content
Definition: FormDataDecoder.cs:468
Waher.Content.Multipart.FormDataDecoder.TryTransferDecode
static bool TryTransferDecode(byte[] Encoded, string TransferEncoding, out byte[] Decoded)
Tries to decode transfer-encoded binary data.
Definition: FormDataDecoder.cs:334
Waher.Content.Multipart.FormDataDecoder.ContentType
const string ContentType
multipart/form-data
Definition: FormDataDecoder.cs:21
Waher.Content.Multipart.FormDataDecoder.DecodeAsync
async Task< object > DecodeAsync(string ContentType, byte[] Data, Encoding Encoding, KeyValuePair< string, string >[] Fields, Uri BaseUri)
Decodes an object.
Definition: FormDataDecoder.cs:72
Waher.Content.Multipart.FormDataDecoder.ContentTypes
string[] ContentTypes
Supported content types.
Definition: FormDataDecoder.cs:35
Waher.Content.Multipart.FormDataDecoder.Encode
static async Task< KeyValuePair< byte[], string > > Encode(IEnumerable< EmbeddedContent > Content)
Encodes multi-part form data
Definition: FormDataDecoder.cs:455
Waher.Content.Text.PlainTextCodec
Plain text encoder/decoder.
Definition: PlainTextCodec.cs:13
Waher.Content.Text.PlainTextCodec.DefaultContentType
const string DefaultContentType
text/plain
Definition: PlainTextCodec.cs:24
Waher.Content.IContentDecoder
Basic interface for Internet Content decoders. A class implementing this interface and having a defau...
Definition: IContentDecoder.cs:14
Waher.Content.Multipart
Definition: AlternativeCodec.cs:8
Waher.Content.Multipart.ContentDisposition
ContentDisposition
Content disposition
Definition: EmbeddedContent.cs:12
Waher.Content.Text
Definition: CsvCodec.cs:9
Waher.Runtime.Inventory.Grade
Grade
Grade enumeration
Definition: Grade.cs:7