/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Tag">The asn1 tag.</param>
/// <param name="constructType">Type of the construct.</param>
public Asn1TagInfo(Asn1Tag asn1Tag, ConstructType constructType)
{
this.Asn1ClassType = Asn1Class.Universal;
this.Asn1ConstructType = constructType;
this.Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
this.Asn1TagType = asn1Tag;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Tag">The asn1 tag.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="asn1Class">The asn1 class.</param>
public Asn1TagInfo(Asn1Tag asn1Tag, ConstructType constructType, Asn1Class asn1Class)
{
this.Asn1ClassType = asn1Class;
this.Asn1ConstructType = constructType;
this.Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
this.Asn1TagType = asn1Tag;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1SnmpTag">The asn1 SNMP tag.</param>
/// <param name="constructType">Type of the construct.</param>
public Asn1TagInfo(Asn1SnmpTag asn1SnmpTag, ConstructType constructType)
{
this.Asn1ClassType = Asn1Class.Application;
this.Asn1ConstructType = constructType;
this.Asn1SnmpTagType = asn1SnmpTag;
this.Asn1TagType = Asn1Tag.NotAsn1Data;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1SnmpTag">The asn1 SNMP tag.</param>
/// <param name="constructType">Type of the construct.</param>
public Asn1TagInfo(Asn1SnmpTag asn1SnmpTag, ConstructType constructType)
{
Asn1ClassType = Asn1Class.Application;
Asn1ConstructType = constructType;
Asn1SnmpTagType = asn1SnmpTag;
Asn1TagType = Asn1Tag.NotAsn1Data;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Object{T}"/> class.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <param name="asn1Tag">Tag number or type of Asn.1 object.</param>
/// <param name="content">Raw content to be decoded.</param>
protected Asn1Object(Asn1Class asn1Class, bool constructed, int asn1Tag, SubStream content)
: base(asn1Class, constructed, asn1Tag)
{
this.RawContent = content;
this.RawContent.Seek(this.RawContent.Length, SeekOrigin.Current);
this.toBeParsed = true;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Tag">The asn1 tag.</param>
/// <param name="constructType">Type of the construct.</param>
public Asn1TagInfo(Asn1Tag asn1Tag, ConstructType constructType)
{
Asn1ClassType = Asn1Class.Universal;
Asn1ConstructType = constructType;
Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
Asn1TagType = asn1Tag;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Tag">The asn1 tag.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="asn1Class">The asn1 class.</param>
public Asn1TagInfo(Asn1Tag asn1Tag, ConstructType constructType, Asn1Class asn1Class)
{
Asn1ClassType = asn1Class;
Asn1ConstructType = constructType;
Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
Asn1TagType = asn1Tag;
}
/// <summary>
/// Writes Identifier octet of ASN.1 object.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="tagNumber">Tag number or type of Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <returns>Encoded identifier octet of ASN.1 object.</returns>
internal static byte[] WriteTag(Asn1Class asn1Class, int tagNumber, bool constructed = false)
{
byte[] tagOctets = null;
var classPart = (int)asn1Class;
var typePart = tagNumber & 0x1F; // clear bits 8 to 6
int tag = classPart;
if (constructed)
{
tag = tag | 0x20;
}
if (asn1Class == Asn1Class.ContextSpecific && tagNumber > 30)
{
tag = tag + 31; // in long form bits 1-5 have value of 1 and tag number is encoded in the following octets
var tagValueOctets = new List <byte>();
tagValueOctets.Add((byte)tag);
DerWriterUtils.SevenBitEncode(tagNumber, tagValueOctets);
tagOctets = tagValueOctets.ToArray();
}
else
{
tag = tag + typePart;
tagOctets = new byte[1] {
(byte)tag
};
}
return(tagOctets);
}
/// <summary>
/// Reads one node as ASN.1 object.
/// </summary>
/// <typeparam name="T">Type of objects to parse. Basically it has to be Asn1BaseObject</typeparam>
/// <param name="foundObject">Parsed ASN.1 Object.</param>
/// <returns>Itself.</returns>
public BerReader ReadOne <T>(out T foundObject)
where T : Asn1ObjectBase
{
var nodeStartOffset = this.inputStream.Position;
// get first byte - Identifier octet
var firstByte = this.inputStream.ReadByte();
// break the cycle when stream ends
if (firstByte == -1)
{
// TODO: return or throw?
// end of stream
foundObject = null;
return(this);
}
// parse type of ASN.1 node
Asn1Class asn1Class = ReadAsn1Class(firstByte);
var constructed = (firstByte & 32) == 32;
// if first byte is not enough to get ASN1 tag, we will read more from input stream
int tag = ReadAsn1Tag(firstByte, this.inputStream);
// read length - Length octet(s) as many as needed
long length = this.ReadLength();
long substreamLength;
// TODO: not sure if it's correct. Need to stop parsing because length of node greater than stream length
if (length > this.inputStream.Length)
{
substreamLength = 0;
foundObject = null;
return(this);
}
substreamLength = length;
if (length == -1)
{
substreamLength = this.inputStream.Length;
}
// read content - Value octets
var contentStream = new SubStream(this.inputStream, substreamLength);
// make an instance of exact ASN.1 object
foundObject = MakeInstanceOfAsn1Object <T>(nodeStartOffset, asn1Class, constructed, tag, contentStream);
return(this);
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Class">The asn1 class.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="tagType">Type of the tag.</param>
internal Asn1TagInfo(int asn1Class, int constructType, int tagType)
{
Asn1ClassType = (Asn1Class)asn1Class;
Asn1ConstructType = (ConstructType)constructType;
if (Asn1ClassType == Asn1Class.Application)
{
Asn1SnmpTagType = (Asn1SnmpTag)tagType;
Asn1TagType = Asn1Tag.NotAsn1Data;
}
else
{
Asn1TagType = (Asn1Tag)tagType;
Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
}
}
/// <summary>
/// Writes Identifier octet of ASN.1 object.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="tagNumber">Tag number or type of Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <returns>Encoded identifier octet of ASN.1 object.</returns>
internal static byte WriteTag(Asn1Class asn1Class, int tagNumber, bool constructed = false)
{
// TODO: support tag number > 30
if (asn1Class == Asn1Class.ContextSpecific && tagNumber > 30)
{
throw new NotSupportedException("Currently only tag numbers 0-30 are supported.");
}
var classPart = (int)asn1Class;
var typePart = tagNumber & 0x1F; // clear bits 8 to 6
int tag = classPart + typePart;
if (constructed)
{
tag = tag | 0x20;
}
return((byte)tag);
}
/// <summary>
/// Encodes the type of the class construct.
/// </summary>
/// <param name="data">The data.</param>
/// <param name="offset">The offset.</param>
/// <param name="asn1Class">The asn1 class.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="tag">The tag.</param>
/// <returns>new offset value in int</returns>
public static int EncodeClassConstructType(this byte[] data, int offset, Asn1Class asn1Class, ConstructType constructType, byte tag)
{
data[offset] = (byte)(((byte)asn1Class << 6) | ((byte)constructType << 5) | tag);
return(offset + 1);
}
/// <summary>
/// Encodes the type of the class construct.
/// </summary>
/// <param name="data">The data.</param>
/// <param name="offset">The offset.</param>
/// <param name="asn1Class">The asn1 class.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="tag">The tag.</param>
/// <returns>new offset value in int</returns>
public static int EncodeClassConstructType(this byte[] data, int offset, Asn1Class asn1Class, ConstructType constructType, byte tag)
{
data[offset] = (byte)(((byte)asn1Class << 6) | ((byte)constructType << 5) | tag);
return offset + 1;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Sequence"/> class.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="content">Content to be encoded.</param>
public Asn1Sequence(Asn1Class asn1Class, List <Asn1ObjectBase> content)
: base(asn1Class, true, (int)Asn1Type.Sequence, content)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Set"/> class.
/// Preferably used when reading SET.
/// The encoding of a set value shall be constructed.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="content">BER encoded value in a Stream.</param>
/// <param name="constructed">Flag if type is constructed or primitive.</param>
internal Asn1Set(Asn1Class asn1Class, SubStream content, bool constructed)
: base(asn1Class, constructed, (int)Asn1Type.Set, content)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Set"/> class.
/// Preferably used when encoding SET.
/// The encoding of a set value shall be constructed.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="content">Content to be encoded.</param>
/// <param name="constructed">Flag if type is constructed or primitive.</param>
public Asn1Set(Asn1Class asn1Class, List <Asn1ObjectBase> content, bool constructed = true)
: base(asn1Class, constructed, (int)Asn1Type.Set, content)
{
}
public Asn1TypeAttribute(Asn1Tag asn1Tag, ConstructType constructType, Asn1Class asn1Class)
{
this.tagInfo = new Asn1TagInfo(asn1Tag, constructType, asn1Class);
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Object{T}"/> class.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <param name="asn1Tag">Tag number or type of Asn.1 object.</param>
/// <param name="content">Content to be encoded.</param>
protected Asn1Object(Asn1Class asn1Class, bool constructed, int asn1Tag, T content)
: base(asn1Class, constructed, asn1Tag)
{
this.content = content;
this.toBeParsed = false;
}
public Asn1TypeAttribute(Asn1Tag asn1Tag, ConstructType constructType, Asn1Class asn1Class)
{
this.tagInfo = new Asn1TagInfo(asn1Tag, constructType, asn1Class);
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Object{T}"/> class.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <param name="asn1Tag">Tag number or type of Asn.1 object.</param>
/// <param name="content">Content to be encoded.</param>
protected Asn1Object(Asn1Class asn1Class, bool constructed, int asn1Tag, T content)
: base(asn1Class, constructed, asn1Tag)
{
this.Content = content;
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1Sequence"/> class.
/// Preferably used when reading SEQUENCE.
/// The encoding of a sequence value shall be constructed.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="content">BER encoded value in a Stream.</param>
/// <param name="constructed">Flag if type is constructed or primitive.</param>
public Asn1Sequence(Asn1Class asn1Class, SubStream content, bool constructed)
: base(asn1Class, constructed, (int)Asn1Type.Sequence, content)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1ObjectBase"/> class.
/// </summary>
/// <param name="asn1Class">Class of given Asn.1 object.</param>
/// <param name="constructed">Constructed/Primitive bit of identifier octet.</param>
/// <param name="asn1Tag">Tag number or type of Asn.1 object.</param>
protected Asn1ObjectBase(Asn1Class asn1Class, bool constructed, int asn1Tag)
{
this.Asn1Class = asn1Class;
this.Constructed = constructed;
this.Asn1Tag = asn1Tag;
}
private static T MakeInstanceOfAsn1Object <T>(long nodeStartOffset, Asn1Class asn1Class, bool constructed, int tag, SubStream content)
where T : Asn1ObjectBase
{
T foundObject;
Asn1ObjectBase shouldBeType = null;
if (asn1Class == Asn1Class.ContextSpecific)
{
shouldBeType = new Asn1ContextSpecific(constructed, tag, content);
}
else
{
switch ((Asn1Type)tag)
{
case Asn1Type.Eoc:
shouldBeType = new Asn1Eoc();
break;
case Asn1Type.Boolean:
shouldBeType = new Asn1Boolean(content, constructed);
break;
case Asn1Type.Integer:
shouldBeType = new Asn1Integer(content, constructed);
break;
case Asn1Type.BitString:
shouldBeType = new Asn1BitString(content, constructed);
break;
case Asn1Type.OctetString:
shouldBeType = new Asn1OctetString(content, constructed);
break;
case Asn1Type.Null:
shouldBeType = new Asn1Null(constructed);
break;
case Asn1Type.ObjectIdentifier:
shouldBeType = new Asn1ObjectIdentifier(content, constructed);
break;
case Asn1Type.Real:
shouldBeType = new Asn1Real(content, constructed);
break;
case Asn1Type.Enumerated:
shouldBeType = new Asn1Enumerated(content, constructed);
break;
case Asn1Type.Utf8String:
shouldBeType = new Asn1Utf8String(content, constructed);
break;
case Asn1Type.RelativeOid:
shouldBeType = new Asn1RelativeOid(content, constructed);
break;
case Asn1Type.Sequence:
shouldBeType = new Asn1Sequence(asn1Class, content, constructed);
break;
case Asn1Type.Set:
shouldBeType = new Asn1Set(asn1Class, content, constructed);
break;
case Asn1Type.NumericString:
shouldBeType = new Asn1NumericString(content, constructed);
break;
case Asn1Type.PrintableString:
shouldBeType = new Asn1PrintableString(content, constructed);
break;
case Asn1Type.T61String:
shouldBeType = new Asn1T61String(content, constructed);
break;
case Asn1Type.Ia5String:
shouldBeType = new Asn1Ia5String(content, constructed);
break;
case Asn1Type.UtcTime:
shouldBeType = new Asn1UtcTime(content, constructed);
break;
case Asn1Type.GeneralizedTime:
shouldBeType = new Asn1GeneralizedTime(content, constructed);
break;
case Asn1Type.GraphicString:
shouldBeType = new Asn1GraphicString(content, constructed);
break;
case Asn1Type.GeneralString:
shouldBeType = new Asn1GeneralString(content, constructed);
break;
case Asn1Type.UniversalString:
shouldBeType = new Asn1UniversalString(content, constructed);
break;
case Asn1Type.BmpString:
shouldBeType = new Asn1BmpString(content, constructed);
break;
case Asn1Type.ObjectDescriptor:
case Asn1Type.External:
case Asn1Type.EmbeddedPdv:
case Asn1Type.VideotexString:
case Asn1Type.VisibleString:
case Asn1Type.CharacterString:
case Asn1Type.LongForm:
default:
throw new NotSupportedException($"ASN.1 tag {tag} is unsupported.");
}
}
foundObject = shouldBeType as T;
// sanity check
if (foundObject == null)
{
throw new FormatException(FormattableString.Invariant($"ASN.1 node at offset {nodeStartOffset} is of type {shouldBeType.GetType()} but expected type was {typeof(T)}"));
}
return(foundObject);
}
/// <summary>
/// Initializes a new instance of the <see cref="Asn1TagInfo"/> struct.
/// </summary>
/// <param name="asn1Class">The asn1 class.</param>
/// <param name="constructType">Type of the construct.</param>
/// <param name="tagType">Type of the tag.</param>
internal Asn1TagInfo(int asn1Class, int constructType, int tagType)
{
this.Asn1ClassType = (Asn1Class)asn1Class;
this.Asn1ConstructType = (ConstructType)constructType;
if (this.Asn1ClassType == Asn1Class.Application)
{
this.Asn1SnmpTagType = (Asn1SnmpTag)tagType;
this.Asn1TagType = Asn1Tag.NotAsn1Data;
}
else
{
this.Asn1TagType = (Asn1Tag)tagType;
this.Asn1SnmpTagType = Asn1SnmpTag.NotSnmpData;
}
}
