Asn1BitString Class Reference

Inheritance diagram for Asn1BitString:

List of all members.

Public Types
enum	StringFormat
Public Member Functions
	Asn1BitString (System.Collections.BitArray bitArray)
	Asn1BitString (System.String value_)
	Asn1BitString (bool[] bitValues)
	Asn1BitString (int numbits_, byte[] data)
	Asn1BitString ()
virtual void	Clear (int bitno)
void	Decode (Asn1MderDecodeBuffer buffer, int length)
virtual void	Decode (Asn1PerDecodeBuffer buffer, long lower, long upper)
override void	Decode (Asn1PerDecodeBuffer buffer)
override void	Decode (Asn1BerDecodeBuffer buffer, bool explicitTagging, int implicitLength)
virtual void	DecodeXER (System.String buffer, System.String attrs)
override void	DecodeXML (System.String buffer, System.String attrs)
virtual void	Encode (Asn1PerOutputStream outs, long lower, long upper)
override void	Encode (Asn1PerOutputStream outs)
override void	Encode (Asn1BerOutputStream outs, bool explicitTagging)
override void	Encode (Asn1XmlEncoder buffer, System.String elemName, System.String nsPrefix)
virtual void	Encode (Asn1XmlEncoder buffer, System.String elemName, System.String nsPrefix, System.String[] namedbits, int[] namedbitindex)
virtual void	Encode (Asn1XerEncoder buffer, System.String elemName, System.String[] namedbits, int[] namedbitindex)
override void	Encode (Asn1XerEncoder buffer, System.String elemName)
void	Encode (Asn1MderOutputStream outs, int length)
virtual void	Encode (Asn1PerEncodeBuffer buffer, long lower, long upper)
override void	Encode (Asn1PerEncodeBuffer buffer)
override int	Encode (Asn1BerEncodeBuffer buffer, bool explicitTagging)
override bool	Equals (System.Object value)
virtual bool	Equals (int nbits, byte[] value)
virtual bool	Get (int bitno)
override int	GetHashCode ()
virtual bool	IsNamedBitStr (System.String buffer)
virtual void	Set (int bitno)
virtual void	Set (int bitno, bool value)
virtual bool[]	ToBoolArray ()
virtual System.String	ToHexString ()
override System.String	ToString ()
Public Attributes
byte[]	mValue
int	numbits
bool	trimZeroBits
Static Public Attributes
static new readonly Asn1Tag	_TAG
static StringFormat	mStringFormat = StringFormat.HEXBIN
Properties
override int	Length [get]
virtual bool	this [int bitno] [get, set]

---

Detailed Description

This is a container class for holding the components of an ASN.1 bit string value.

---

Member Enumeration Documentation

enum StringFormat

Defines possible string fomrats.

The HEX constant describes the string format as hex digit value (e.g. 0123456789ABCDEF).

The BITS constant describes the string format as binary digit value (e.g. only 0 and 1 digits).

The ASN1VALUE constant describes the string format as hex or binary digit value. The binary string value will end with letter 'B' and hex string value will end with letter 'H' (e.g. '0101'B or '11'H ). If the number of bits is less than or equal to 16, than it will be printed as Binary digits, else as Hex digits.

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Constructor & Destructor Documentation

Asn1BitString

(

)

This constructor creates an empty bit string that can be used in a Decode method call to receive a bit string value.

Asn1BitString	(	int	numbits_,
		byte[]	data
	)

This constructor initializes a bit string with the given number of bits and data.

Parameters:

	numbits_	Number of bits
	data	Binary bit string contents

Asn1BitString

(

bool[]

bitValues

)

This constructor initializes a bit string from the given boolean array. Each array position corresponds to a bit in the bit string.

Parameters:

bitValues

The boolean array

Asn1BitString

(

System.String

value_

)

This constructor parses the given ASN.1 value text (either a binary or hex data string) and assigns the values to the internal bit string.

Examples of valid value formats are as follows:

Binary string: '11010010111001'B

Hex string: '0fa56920014abc'H

Parameters:

value_

The ASN.1 value specification text

Asn1BitString

(

System.Collections.BitArray

bitArray

)

This constructor initializes a bit string from the given BitSet object.

Parameters:

bitArray

C# BitArray object

---

Member Function Documentation

virtual void Clear

(

int

bitno

)

[virtual]

This method clears the given bit in the bit string.

Parameters:

bitno

The zero-based index of the bit to clear. The bit numbers start at zero and with the MSB of the first byte and progress from left to right.

void Decode	(	Asn1MderDecodeBuffer	buffer,
		int	length
	)

Decode a BIT STRING from the MDER encoding into this object. Exactly the given length of bits will be decoded.

Parameters:

length

This should be 8, 16, or 32, as these are the only lengths MDER supports. However, this is not checked here as it should be able to be checked at code generation time.

virtual void Decode	(	Asn1PerDecodeBuffer	buffer,
		long	lower,
		long	upper
	)			[virtual]

This method decodes a sized ASN.1 bit string value using the packed encoding rules (PER).

Parameters:

	buffer	Decode message buffer object
	lower	Lower bound (inclusive) of size constraint
	upper	Upper bound (inclusive) of size constraint

override void Decode

(

Asn1PerDecodeBuffer

buffer

)

[virtual]

This method decodes an ASN.1 bit string value using the packed encoding rules (PER). The string is assumed to not contain a size constraint.

Parameters:

buffer

Decode message buffer object

Reimplemented from Asn1Type.

override void Decode	(	Asn1BerDecodeBuffer	buffer,
		bool	explicitTagging,
		int	implicitLength
	)			[virtual]

This method decodes an ASN.1 bit string value using the BER or DER encoding rules. The UNIVERSAL tag value and length are decoded if explicit tagging is specified.

Parameters:

	buffer	Decode message buffer object
	explicitTagging	Flag indicating element is explicitly tagged
	implicitLength	Length of contents if implicit

Reimplemented from Asn1Type.

virtual void DecodeXER	(	System.String	buffer,
		System.String	attrs
	)			[virtual]

This method decodes ASN.1 bit string type using the XML encoding rules (XER).

Parameters:

	buffer	String containing data to be decoded
	attrs	Attributes string from element tag

override void DecodeXML	(	System.String	buffer,
		System.String	attrs
	)

This method decodes ASN.1 bit string type using the XML decoding as specified in the XML Schema standard.

Parameters:

	buffer	String containing data to be decoded
	attrs	Attributes string from element tag

virtual void Encode	(	Asn1PerOutputStream	outs,
		long	lower,
		long	upper
	)			[virtual]

This method encodes a size-constrained ASN.1 bit string value using the packed encoding rules (PER) into the stream. The value to be encoded is stored in the 'numbits' and 'mValue' public member variables within this class.

Also throws any exception thrown by the underlying Asn1PerOutputStream.

Parameters:

	outs	PER Output Stream object
	lower	Lower bound (inclusive) of size constraint
	upper	Upper bound (inclusive) of size constraint

Exceptions:

Asn1Exception

Thrown, if operation is failed.

override void Encode

(

Asn1PerOutputStream

outs

)

[virtual]

This method encodes an unconstrained ASN.1 bit string value using the packed encoding rules (PER)into the stream. The value to be encoded is stored in the 'numbits' and 'mValue' public member variables within this class.

Also throws any exception thrown by the underlying Asn1PerOutputStream.

Parameters:

outs

PER Output Stream object

Exceptions:

Asn1Exception

Thrown, if operation is failed.

Reimplemented from Asn1Type.

override void Encode	(	Asn1BerOutputStream	outs,
		bool	explicitTagging
	)			[virtual]

This method encodes and writes to the stream an ASN.1 bit string value including the UNIVERSAL tag value and length if explicit tagging is specified. This overloaded version uses the Basic Encoding Rules (BER).

Throws, exception thrown by the underlying System.IO.Stream object.

Parameters:

	outs	BER Output Stream object
	explicitTagging	Flag indicating explicit tagging should be done

Exceptions:

Asn1Exception

Thrown, if operation is failed.

Reimplemented from Asn1Type.

override void Encode	(	Asn1XmlEncoder	buffer,
		System.String	elemName,
		System.String	nsPrefix
	)			[virtual]

This method encodes ASN.1 bit string type using the XML Encoding as specified in the XML Schema standard.

Parameters:

	buffer	Encode message buffer object
	elemName	XML element name used to wrap string
	nsPrefix	XML element namespace name

Reimplemented from Asn1Type.

virtual void Encode	(	Asn1XmlEncoder	buffer,
		System.String	elemName,
		System.String	nsPrefix,
		System.String[]	namedbits,
		int[]	namedbitindex
	)			[virtual]

This method encodes ASN.1 bit string type using the XML Encoding as specified in the XML Schema standard.

Parameters:

	buffer	Encode message buffer object
	elemName	XML element name used to wrap string
	nsPrefix	XML element namespace name
	namedbits	Array of named bits
	namedbitindex	Arrat of named bits index values

virtual void Encode	(	Asn1XerEncoder	buffer,
		System.String	elemName,
		System.String[]	namedbits,
		int[]	namedbitindex
	)			[virtual]

This method encodes ASN.1 bit string type using the XML Encoding as specified in the itu-t XER standard.

Parameters:

	buffer	Encode message buffer object
	elemName	XML element name used to wrap string
	namedbits	Array of named bits
	namedbitindex	Arrat of named bits index values

override void Encode	(	Asn1XerEncoder	buffer,
		System.String	elemName
	)			[virtual]

This method encodes ASN.1 bit string type using the XML encoding rules (XER).

Parameters:

	buffer	Encode message buffer object
	elemName	XML element name used to wrap string

Reimplemented from Asn1Type.

void Encode	(	Asn1MderOutputStream	outs,
		int	length
	)

Encode this BIT STRING into the MDER encoding. The length of this BIT STRING must match the given length.

Parameters:

length

This should be 8, 16, or 32, as these are the only lengths MDER supports. However, this is not checked here as it should be able to be checked at code generation time. We only check here that the actual and given lengths match.

virtual void Encode	(	Asn1PerEncodeBuffer	buffer,
		long	lower,
		long	upper
	)			[virtual]

This method encodes a size-constrained ASN.1 bit string value using the packed encoding rules (PER). The value to be encoded is stored in the 'numbits' and 'mValue' public member variables within this class.

Parameters:

	buffer	Encode message buffer object
	lower	Lower bound (inclusive) of size constraint
	upper	Upper bound (inclusive) of size constraint

override void Encode

(

Asn1PerEncodeBuffer

buffer

)

[virtual]

This method encodes an unconstrained ASN.1 bit string value using the packed encoding rules (PER). The value to be encoded is stored in the 'numbits' and 'mValue' public member variables within this class.

Parameters:

buffer

Encode message buffer object

Reimplemented from Asn1Type.

override int Encode	(	Asn1BerEncodeBuffer	buffer,
		bool	explicitTagging
	)			[virtual]

This method encodes an ASN.1 bit string value using the BER or DER encoding rules. The UNIVERSAL tag value and length are encoded if explicit tagging is specified.

Parameters:

	buffer	Encode message buffer object
	explicitTagging	Flag indicating explicit tagging should be done

Returns:

Length of component or negative status value

Reimplemented from Asn1Type.

override bool Equals

(

System.Object

value

)

This method compares this bit string value to the given value for equality. This method assumes all unused bits in the last byte are set to zero.

Parameters:

value

The Object to compare with the current Object. Object should be instance of Asn1BitString.

Returns:

true if the specified Object is equal to the current Object; otherwise, false.

virtual bool Equals	(	int	nbits,
		byte[]	value
	)			[virtual]

This method compares this bit string value to the given value for equality. This method assumes all unused bits in the last byte are set to zero.

Parameters:

	nbits	The number of bits to compare from the byte array.
	value	The byte array to compare with the current Object.

Returns:

true if the specified bit array is equal to the current Object; otherwise, false.

virtual bool Get

(

int

bitno

)

[virtual]

Gets the value of the bit at a specific position in the bit array.

Parameters:

bitno

The zero-based index of the bit to get. The bit numbers start at zero and with the MSB of the first byte and progress from left to right.

Returns:

true if bit is set; otherwise false.

override int GetHashCode

(

)

Serves as a hash function for a particular type, suitable for use in hashing algorithms and data structures like a hash table.

Returns:

A hash code for the current Object.

virtual bool IsNamedBitStr

(

System.String

buffer

)

[virtual]

This method determines is the input character string represented as named bit string or as bits sequence. It is used for XML decoding.

Parameters:

buffer

Bit string as string to be tested.

Returns:

true, if bit string is represented as sequnece of identifiers.

virtual void Set

(

int

bitno

)

[virtual]

This method will set the given bit number to one (1). It will expand the existing bit array if it needs to.

Parameters:

bitno

The zero-based index of the bit to set. The bit numbers start at zero and with the MSB of the first byte and progress from left to right.

virtual void Set	(	int	bitno,
		bool	value
	)			[virtual]

This method sets the given bit number in the bit string with given value. It will expand the existing bit array if it needs to.

Parameters:

	bitno	The zero-based index of the bit to set. The bit numbers start at zero and with the MSB of the first byte and progress from left to right.
	value	The Boolean value to assign to the bit.

virtual bool [] ToBoolArray

(

)

[virtual]

This method converts the bit string stored in this object to a boolean array.

Returns:

Boolean array value

virtual System.String ToHexString

(

)

[virtual]

This method will return a hex string representation of the bit string value. The output format is a string of hex bytes with no extra delimiting characters (ex. 0D56EF).

Returns:

Stringified representation of the value

override System.String ToString

(

)

This method will return a string representation of the bit string value. The output format is a string of hex digits/binary digits according to the value set for mStringFormat variable.

Returns:

String representation of the value

---

Member Data Documentation

new readonly Asn1Tag _TAG [static]

The _TAG constant describes the universal tag for this data type (UNIVERSAL 3).

Reimplemented from Asn1Type.

StringFormat mStringFormat = StringFormat.HEXBIN [static]

The mStringFormat variable can be used to set the string format for print() or event handler calls or toString() functions. The possible options are: HEX, BITS, ASN1VALUE HEX is the default format.

byte [] mValue

This variable holds the bit string value. These are the bits that are encoded when encode is invoked. It is also where the decoded bit string is stored after a Decode operation.

int numbits

This variable contains the number of bits in the bit string value.

bool trimZeroBits

This variable tells whether or not to trim zero bits at the end of a bit string encoding. In CER and DER, it is required to trim trailing zero bits if the bit string is a Named Bit String.

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Property Documentation

override int Length [get]

Gets the length of the BIT STRING in bits.

Value: Number of bits.

Reimplemented from Asn1Type.

virtual bool this[int bitno] [get, set]

Gets or Sets the given bit in the bit string. It will expand the existing bit array if it needs to set the bit value.

Parameters:

bitno

The position of the bit in bit array

Value: true if bit is set; otherwise false.