pcpp::SSLClientHelloMessage Class Reference

#include <SSLHandshake.h>

Inheritance diagram for pcpp::SSLClientHelloMessage:

Classes
struct	ClientHelloTLSFingerprint

Public Member Functions
	SSLClientHelloMessage (uint8_t *data, size_t dataLen, SSLHandshakeLayer *container)
ssl_tls_client_server_hello *	getClientHelloHeader () const
SSLVersion	getHandshakeVersion () const
uint8_t	getSessionIDLength () const
uint8_t *	getSessionID () const
int	getCipherSuiteCount () const
SSLCipherSuite *	getCipherSuite (int index) const
uint16_t	getCipherSuiteID (int index, bool &isValid) const
uint8_t	getCompressionMethodsValue () const
int	getExtensionCount () const
uint16_t	getExtensionsLength () const
SSLExtension *	getExtension (int index) const
SSLExtension *	getExtensionOfType (uint16_t type) const
SSLExtension *	getExtensionOfType (SSLExtensionType type) const
template<class TExtension >
TExtension *	getExtensionOfType () const
ClientHelloTLSFingerprint	generateTLSFingerprint () const
std::string	toString () const override
Public Member Functions inherited from pcpp::SSLHandshakeMessage
virtual SSLHandshakeType	getHandshakeType () const
virtual size_t	getMessageLength () const
virtual bool	isMessageComplete () const
SSLHandshakeLayer *	getContainingLayer () const

Additional Inherited Members
Static Public Member Functions inherited from pcpp::SSLHandshakeMessage
static SSLHandshakeMessage *	createHandshakeMessage (uint8_t *data, size_t dataLen, SSLHandshakeLayer *container)

Detailed Description

Represents a client-hello message (type 1). Inherits from SSLHandshakeMessage and adds parsing of all fields of this message including the message extensions, cipher-suite list, etc.

Constructor & Destructor Documentation

SSLClientHelloMessage()

pcpp::SSLClientHelloMessage::SSLClientHelloMessage	(	uint8_t *	data,
		size_t	dataLen,
		SSLHandshakeLayer *	container
	)

C'tor for this class. Currently only in use in SSLHandshakeMessage::createHandshakeMessage() and shouldn't be used by a user

Parameters

[in]	data	The message as raw data
[in]	dataLen	Message raw data length in bytes
[in]	container	The SSL handshake layer which shall contain this message

Member Function Documentation

generateTLSFingerprint()

ClientHelloTLSFingerprint pcpp::SSLClientHelloMessage::generateTLSFingerprint

(

)

const

TLS fingerprinting is a way to identify client applications using the details in the TLS Client Hello packet. It was initially introduced by Lee Brotherston in his 2015 research: https://blog.squarelemon.com/tls-fingerprinting/ This implementation of TLS fingerprint is a C++ version of Salesforce's JA3 open source project (originally written in Python and Zeek): https://engineering.salesforce.com/tls-fingerprinting-with-ja3-and-ja3s-247362855967

Returns

A SSLClientHelloMessage::ClientHelloTLSFingerprint struct that contains all the elements needed for creating a TLS fingerprint out of this Client Hello message. This struct has also methods to extract the TLS fingerprint itself in a string or MD5 formats

getCipherSuite()

SSLCipherSuite* pcpp::SSLClientHelloMessage::getCipherSuite

(

int

index

)

const

Get a pointer to a cipher-suite by index. The cipher-suites are numbered according to their order of appearance in the message. If index is out of bounds (less than 0 or larger than total amount of cipher suites) nullptr will be returned. nullptr will also be returned if the cipher-suite ID is unknown. If you still want to get the cipher-suite ID you can use getCipherSuiteID()

Parameters

[in]

index

The index of the cipher-suite to return

Returns

The pointer to the cipher-suite object or nullptr if index is out of bounds

getCipherSuiteCount()

int pcpp::SSLClientHelloMessage::getCipherSuiteCount

(

)

const

Returns

The number of cipher-suites included in this message

getCipherSuiteID()

uint16_t pcpp::SSLClientHelloMessage::getCipherSuiteID	(	int	index,
		bool &	isValid
	)		const

Get the cipher-suite ID by index. This method just parses the ID from the client-hello message and returns it. To get more information on the cipher-suite you can use the getCipherSuite() method

Parameters

[in]	index	The index of the cipher-suite to return
[out]	isValid	Set to "true" if parsing succeeded and the return value is valid or "false" if: (1) the index is out-of-bounds (less than 0 or larger than total amount of cipher suites) or (2) the parsing failed. If the value is "false" the return value can be ignored

Returns

The cipher-suite ID if "isValid" is set to "true". If "isValid" is set to "false" the return value can be ignored

getClientHelloHeader()

ssl_tls_client_server_hello* pcpp::SSLClientHelloMessage::getClientHelloHeader ( ) const

inline

Returns

A struct containing common fields for client-hello and server-hello messages. Notice this points directly to the data, so every change will change the actual packet data

getCompressionMethodsValue()

uint8_t pcpp::SSLClientHelloMessage::getCompressionMethodsValue

(

)

const

Returns

The value of the compression method byte

getExtension()

SSLExtension* pcpp::SSLClientHelloMessage::getExtension

(

int

index

)

const

Get a pointer to an extension by index. The extensions are numbered according to their order of appearance in the message. If index is out of bounds (less than 0 or larger than total amount of extensions) nullptr will be returned

Parameters

[in]

index

The index of the extension to return

Returns

The pointer to the extension or nullptr if index is out of bounds

getExtensionCount()

int pcpp::SSLClientHelloMessage::getExtensionCount

(

)

const

Returns

The number of extensions in this message

getExtensionOfType() [1/3]

template<class TExtension >

TExtension * pcpp::SSLClientHelloMessage::getExtensionOfType

Get a pointer to an extension by its class type. This is a templated method that is used with the type of the requested extension and returns the first extension instance of this type

Returns

A pointer to the extension object or nullptr if this extension type doesn't exist in this message

getExtensionOfType() [2/3]

SSLExtension* pcpp::SSLClientHelloMessage::getExtensionOfType

(

SSLExtensionType

type

)

const

Get a pointer to an extension by its enum type

Parameters

[in]

type

The type of extension to return

Returns

A pointer to the extension object or nullptr if this type doesn't exist in this message

getExtensionOfType() [3/3]

SSLExtension* pcpp::SSLClientHelloMessage::getExtensionOfType

(

uint16_t

type

)

const

Get a pointer to an extension by numeric type field. Every extension has a 2-byte numeric value representing its type (for example: renegotiation info extension type is 0x1ff). This method gets the type and returns a pointer to the extension object

Parameters

[in]

type

The 2-byte numeric type of the extension

Returns

A pointer to the extension object of nullptr if this type doesn't exist in this message

getExtensionsLength()

uint16_t pcpp::SSLClientHelloMessage::getExtensionsLength

(

)

const

Returns

The size (in bytes) of all extensions data in this message. Extracted from the "extensions length" field

getHandshakeVersion()

SSLVersion pcpp::SSLClientHelloMessage::getHandshakeVersion

(

)

const

Returns

Handshake SSL/TLS version (notice it may be different than SSLLayer::getRecordVersion(). Each client-hello or server-hello message has both record version and handshake version and they may differ from one another)

getSessionID()

uint8_t* pcpp::SSLClientHelloMessage::getSessionID

(

)

const

Returns

Session ID as byte array. If server-hello message doesn't include session ID nullptr will be returned

getSessionIDLength()

uint8_t pcpp::SSLClientHelloMessage::getSessionIDLength

(

)

const

Returns

Session ID length in bytes. If server-hello message doesn't include session ID 0 will be returned

toString()

std::string pcpp::SSLClientHelloMessage::toString ( ) const

overridevirtual

Returns

A string representation of the message type (e.g "Client Hello message")

Implements pcpp::SSLHandshakeMessage.