CrescendoDLL.PCSC.BerTLVBuffer Class Reference

Represents a BER-TLV (Binary Encoded Representation Tag-Length-Value) data buffer for PIV (Personal Identity Verification) data object handling. More...

Public Member Functions
BerTLVBuffer	AddTag (string tag, byte[]? data)
	Adds or updates a tag-value pair in the buffer.
	BerTLVBuffer (byte[]? data, string berTLVTag)
	Constructs a BER-TLV buffer from raw card response data.
byte[]	ConstructDataFieldFromBerTLVBuffer ()
	Constructs complete PIV data field with tag list.
BerTLVBuffer	RemoveTag (string tag)
	Removes a tag-value pair from the buffer.
byte[]	ToByte ()
	Serializes the buffer to BER-TLV formatted byte array.

Public Attributes
Dictionary< string, byte[]>	Content = new()
	Dictionary of TLV components (Tag-Length-Value entries)
bool	IsEmpty = true
	Indicates if the buffer contains no valid TLV data.

Properties
string	BERTLVTag = default! [get, set]
	Main BER-TLV tag identifier for the data object.
byte	GeneralTag = 0x53 [get, set]
	General encapsulation tag (default: 0x53 for Discovery Object)

Detailed Description

Represents a BER-TLV (Binary Encoded Representation Tag-Length-Value) data buffer for PIV (Personal Identity Verification) data object handling.

Implements encoding/decoding of PIV data objects per NIST SP 800-73-4 specifications.

Constructor & Destructor Documentation

BerTLVBuffer()

CrescendoDLL.PCSC.BerTLVBuffer.BerTLVBuffer ( byte?[]  data, string  berTLVTag  )

inline

Constructs a BER-TLV buffer from raw card response data.

Parameters

data	Raw BER-TLV formatted byte array (null creates empty buffer)
berTLVTag	Main tag identifying the PIV data object

Parsing behavior:

• Ignores GeneralTag occurrences during parsing
• Stores nested tags in Content dictionary
• Handles ASN.1 length encoding automatically

Member Function Documentation

AddTag()

BerTLVBuffer CrescendoDLL.PCSC.BerTLVBuffer.AddTag ( string  tag, byte?[]  data  )

inline

Adds or updates a tag-value pair in the buffer.

Parameters

tag	2-character hex tag identifier (e.g., "80")
data	Tag value (null stores empty byte array)

Returns

Current instance for method chaining

Automatically replaces existing entries with same tag

ConstructDataFieldFromBerTLVBuffer()

byte[] CrescendoDLL.PCSC.BerTLVBuffer.ConstructDataFieldFromBerTLVBuffer ( )

inline

Constructs complete PIV data field with tag list.

Returns

BER-TLV structure formatted as:

• 0x5C (Tag List Tag)
• Main tag + length
• Serialized content from CrescendoDLL.PCSC.BerTLVBuffer.ToByte

RemoveTag()

BerTLVBuffer CrescendoDLL.PCSC.BerTLVBuffer.RemoveTag ( string  tag )

inline

Removes a tag-value pair from the buffer.

Parameters

tag	2-character hex tag identifier

Returns

Current instance for method chaining

ToByte()

byte[] CrescendoDLL.PCSC.BerTLVBuffer.ToByte ( )

inline

Serializes the buffer to BER-TLV formatted byte array.

Returns

Byte array containing:

• GeneralTag (0x53/0x7E)
• ASN.1 length encoding
• Concatenated tag-length-value entries

Returns [GeneralTag, 0x00] for empty buffers

Member Data Documentation

Content

Dictionary<string, byte[]> CrescendoDLL.PCSC.BerTLVBuffer.Content = new()

Dictionary of TLV components (Tag-Length-Value entries)

Key: 2-character hex string tag (e.g., "80") Value: Byte array containing tag's value

IsEmpty

bool CrescendoDLL.PCSC.BerTLVBuffer.IsEmpty = true

Indicates if the buffer contains no valid TLV data.

Property Documentation

BERTLVTag

string CrescendoDLL.PCSC.BerTLVBuffer.BERTLVTag = default!

getset

Main BER-TLV tag identifier for the data object.

Hexadecimal string representation of the tag (e.g., "5FC107")

GeneralTag

byte CrescendoDLL.PCSC.BerTLVBuffer.GeneralTag = 0x53

getset

General encapsulation tag (default: 0x53 for Discovery Object)

Defaults to 0x53 (Discovery Object Tag). May be 0x7E (Data Object Content Tag) for other PIV data objects.