ASN1StreamParser.cs 5.8 KB

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  1. #if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
  2. #pragma warning disable
  3. using System;
  4. using System.IO;
  5. namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Asn1
  6. {
  7. public class Asn1StreamParser
  8. {
  9. private readonly Stream _in;
  10. private readonly int _limit;
  11. private readonly byte[][] tmpBuffers;
  12. public Asn1StreamParser(
  13. Stream inStream)
  14. : this(inStream, Asn1InputStream.FindLimit(inStream))
  15. {
  16. }
  17. public Asn1StreamParser(
  18. Stream inStream,
  19. int limit)
  20. {
  21. if (!inStream.CanRead)
  22. throw new ArgumentException("Expected stream to be readable", "inStream");
  23. this._in = inStream;
  24. this._limit = limit;
  25. this.tmpBuffers = new byte[16][];
  26. }
  27. public Asn1StreamParser(
  28. byte[] encoding)
  29. : this(new MemoryStream(encoding, false), encoding.Length)
  30. {
  31. }
  32. internal IAsn1Convertible ReadIndef(int tagValue)
  33. {
  34. // Note: INDEF => CONSTRUCTED
  35. // TODO There are other tags that may be constructed (e.g. BIT_STRING)
  36. switch (tagValue)
  37. {
  38. case Asn1Tags.External:
  39. return new DerExternalParser(this);
  40. case Asn1Tags.OctetString:
  41. return new BerOctetStringParser(this);
  42. case Asn1Tags.Sequence:
  43. return new BerSequenceParser(this);
  44. case Asn1Tags.Set:
  45. return new BerSetParser(this);
  46. default:
  47. throw new Asn1Exception("unknown BER object encountered: 0x" + tagValue.ToString("X"));
  48. }
  49. }
  50. internal IAsn1Convertible ReadImplicit(bool constructed, int tag)
  51. {
  52. if (_in is IndefiniteLengthInputStream)
  53. {
  54. if (!constructed)
  55. throw new IOException("indefinite length primitive encoding encountered");
  56. return ReadIndef(tag);
  57. }
  58. if (constructed)
  59. {
  60. switch (tag)
  61. {
  62. case Asn1Tags.Set:
  63. return new DerSetParser(this);
  64. case Asn1Tags.Sequence:
  65. return new DerSequenceParser(this);
  66. case Asn1Tags.OctetString:
  67. return new BerOctetStringParser(this);
  68. }
  69. }
  70. else
  71. {
  72. switch (tag)
  73. {
  74. case Asn1Tags.Set:
  75. throw new Asn1Exception("sequences must use constructed encoding (see X.690 8.9.1/8.10.1)");
  76. case Asn1Tags.Sequence:
  77. throw new Asn1Exception("sets must use constructed encoding (see X.690 8.11.1/8.12.1)");
  78. case Asn1Tags.OctetString:
  79. return new DerOctetStringParser((DefiniteLengthInputStream)_in);
  80. }
  81. }
  82. throw new Asn1Exception("implicit tagging not implemented");
  83. }
  84. internal Asn1Object ReadTaggedObject(bool constructed, int tag)
  85. {
  86. if (!constructed)
  87. {
  88. // Note: !CONSTRUCTED => IMPLICIT
  89. DefiniteLengthInputStream defIn = (DefiniteLengthInputStream)_in;
  90. return new DerTaggedObject(false, tag, new DerOctetString(defIn.ToArray()));
  91. }
  92. Asn1EncodableVector v = ReadVector();
  93. if (_in is IndefiniteLengthInputStream)
  94. {
  95. return v.Count == 1
  96. ? new BerTaggedObject(true, tag, v[0])
  97. : new BerTaggedObject(false, tag, BerSequence.FromVector(v));
  98. }
  99. return v.Count == 1
  100. ? new DerTaggedObject(true, tag, v[0])
  101. : new DerTaggedObject(false, tag, DerSequence.FromVector(v));
  102. }
  103. public virtual IAsn1Convertible ReadObject()
  104. {
  105. int tag = _in.ReadByte();
  106. if (tag == -1)
  107. return null;
  108. // turn of looking for "00" while we resolve the tag
  109. Set00Check(false);
  110. //
  111. // calculate tag number
  112. //
  113. int tagNo = Asn1InputStream.ReadTagNumber(_in, tag);
  114. bool isConstructed = (tag & Asn1Tags.Constructed) != 0;
  115. //
  116. // calculate length
  117. //
  118. int length = Asn1InputStream.ReadLength(_in, _limit);
  119. if (length < 0) // indefinite length method
  120. {
  121. if (!isConstructed)
  122. throw new IOException("indefinite length primitive encoding encountered");
  123. IndefiniteLengthInputStream indIn = new IndefiniteLengthInputStream(_in, _limit);
  124. Asn1StreamParser sp = new Asn1StreamParser(indIn, _limit);
  125. if ((tag & Asn1Tags.Application) != 0)
  126. {
  127. return new BerApplicationSpecificParser(tagNo, sp);
  128. }
  129. if ((tag & Asn1Tags.Tagged) != 0)
  130. {
  131. return new BerTaggedObjectParser(true, tagNo, sp);
  132. }
  133. return sp.ReadIndef(tagNo);
  134. }
  135. else
  136. {
  137. DefiniteLengthInputStream defIn = new DefiniteLengthInputStream(_in, length);
  138. if ((tag & Asn1Tags.Application) != 0)
  139. {
  140. return new DerApplicationSpecific(isConstructed, tagNo, defIn.ToArray());
  141. }
  142. if ((tag & Asn1Tags.Tagged) != 0)
  143. {
  144. return new BerTaggedObjectParser(isConstructed, tagNo, new Asn1StreamParser(defIn));
  145. }
  146. if (isConstructed)
  147. {
  148. // TODO There are other tags that may be constructed (e.g. BitString)
  149. switch (tagNo)
  150. {
  151. case Asn1Tags.OctetString:
  152. //
  153. // yes, people actually do this...
  154. //
  155. return new BerOctetStringParser(new Asn1StreamParser(defIn));
  156. case Asn1Tags.Sequence:
  157. return new DerSequenceParser(new Asn1StreamParser(defIn));
  158. case Asn1Tags.Set:
  159. return new DerSetParser(new Asn1StreamParser(defIn));
  160. case Asn1Tags.External:
  161. return new DerExternalParser(new Asn1StreamParser(defIn));
  162. default:
  163. throw new IOException("unknown tag " + tagNo + " encountered");
  164. }
  165. }
  166. // Some primitive encodings can be handled by parsers too...
  167. switch (tagNo)
  168. {
  169. case Asn1Tags.OctetString:
  170. return new DerOctetStringParser(defIn);
  171. }
  172. try
  173. {
  174. return Asn1InputStream.CreatePrimitiveDerObject(tagNo, defIn, tmpBuffers);
  175. }
  176. catch (ArgumentException e)
  177. {
  178. throw new Asn1Exception("corrupted stream detected", e);
  179. }
  180. }
  181. }
  182. private void Set00Check(
  183. bool enabled)
  184. {
  185. if (_in is IndefiniteLengthInputStream)
  186. {
  187. ((IndefiniteLengthInputStream) _in).SetEofOn00(enabled);
  188. }
  189. }
  190. internal Asn1EncodableVector ReadVector()
  191. {
  192. Asn1EncodableVector v = new Asn1EncodableVector();
  193. IAsn1Convertible obj;
  194. while ((obj = ReadObject()) != null)
  195. {
  196. v.Add(obj.ToAsn1Object());
  197. }
  198. return v;
  199. }
  200. }
  201. }
  202. #pragma warning restore
  203. #endif