cfg

Documentation

Overview

Package cfg is used to generate Binary versions of C2 Profiles and can be used to create automatic Profile 'Groups' with multiple communication and encoding types to be used by a Single session.

Index

• Constants
• Variables
• func Bytes(s ...Setting) []byte
• func JSON(s ...Setting) ([]byte, error)
• func Write(w io.Writer, s ...Setting) error
• type Accepter
• type Config
  • func Pack(s ...Setting) Config
  • func (c *Config) Add(s ...Setting)
  • func (c *Config) AddGroup(s ...Setting)
  • func (c Config) Build() (Profile, error)
  • func (c Config) Bytes() []byte
  • func (c Config) Group(p int) Config
  • func (c Config) Groups() int
  • func (c Config) Len() int
  • func (c Config) MarshalJSON() ([]byte, error)
  • func (c Config) String() string
  • func (c *Config) UnmarshalJSON(b []byte) error
  • func (c Config) Validate() error
  • func (c Config) Write(w io.Writer) error
• type Connector
• type Group
  • func (g *Group) Connect(x context.Context, s string) (net.Conn, error)
  • func (g *Group) Jitter() int8
  • func (g *Group) KillDate() (time.Time, bool)
  • func (g *Group) Len() int
  • func (g *Group) Less(i, j int) bool
  • func (g *Group) Listen(x context.Context, s string) (net.Listener, error)
  • func (g *Group) MarshalBinary() ([]byte, error)
  • func (g *Group) Next() (string, Wrapper, Transform)
  • func (g *Group) Sleep() time.Duration
  • func (g *Group) Swap(i, j int)
  • func (g *Group) Switch(e bool) bool
  • func (g *Group) TrustedKey(k data.PublicKey) bool
  • func (g *Group) WorkHours() *WorkHours
• type MultiWrapper
  • func (m MultiWrapper) Unwrap(r io.Reader) (io.Reader, error)
  • func (m MultiWrapper) Wrap(w io.WriteCloser) (io.WriteCloser, error)
• type Profile
  • func Build(s ...Setting) (Profile, error)
  • func File(s string) (Profile, error)
  • func Raw(b []byte) (Profile, error)
  • func Reader(r io.Reader) (Profile, error)
• type Setting
  • func ConnectIP(p uint) Setting
  • func ConnectMuTLS(ver uint16, ca, pem, key []byte) Setting
  • func ConnectTLSCerts(ver uint16, pem, key []byte) Setting
  • func ConnectTLSEx(ver uint16) Setting
  • func ConnectTLSExCA(ver uint16, ca []byte) Setting
  • func ConnectWC2(url, host, agent string, headers map[string]string) Setting
  • func Host(s string) Setting
  • func Jitter(n uint) Setting
  • func KeyPin(k data.PublicKey) Setting
  • func KillDate(t time.Time) Setting
  • func Sleep(t time.Duration) Setting
  • func TransformB64Shift(s int) Setting
  • func TransformDNS(n ...string) Setting
  • func Weight(w uint) Setting
  • func WrapAES(k, iv []byte) Setting
  • func WrapCBK(a, b, c, d byte) Setting
  • func WrapCBKSize(s, a, b, c, d byte) Setting
  • func WrapXOR(k []byte) Setting
• type Static
  • func (s Static) Connect(x context.Context, a string) (net.Conn, error)
  • func (s Static) Jitter() int8
  • func (s Static) KillDate() (time.Time, bool)
  • func (s Static) Listen(x context.Context, a string) (net.Listener, error)
  • func (s Static) Next() (string, Wrapper, Transform)
  • func (s Static) Sleep() time.Duration
  • func (Static) Switch(_ bool) bool
  • func (s Static) TrustedKey(k data.PublicKey) bool
  • func (s Static) WorkHours() *WorkHours
• type Transform
• type WorkHours
  • func (w WorkHours) Empty() bool
  • func (w WorkHours) MarshalStream(s data.Writer) error
  • func (w WorkHours) String() string
  • func (w *WorkHours) UnmarshalStream(r data.Reader) error
  • func (w WorkHours) Verify() error
  • func (w WorkHours) Work() time.Duration
• type Wrapper

Constants

const (
	// ConnectTCP will provide a TCP connection setting to the generated Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	ConnectTCP = cBit(0xC0)
	// ConnectTLS will provide a TLS over TCP connection setting to the generated
	// Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	//
	// This hint cannot be used as a Listener.
	ConnectTLS = cBit(0xC1)
	// ConnectUDP will provide a UCO connection setting to the generated Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	ConnectUDP = cBit(0xC2)
	// ConnectICMP will provide a ICMP connection setting to the generated Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	ConnectICMP = cBit(0xC3)
	// ConnectPipe will provide a Pipe connection setting to the generated Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	ConnectPipe = cBit(0xC4)
	// ConnectTLSNoVerify will provide a TLS over TCP connection setting to the
	// generated Profile.
	//
	// If multiple connections are contained in the current Config Group, a
	// 'ErrMultipleConnections' error will be returned during a build.
	//
	// This hint cannot be used as a Listener.
	ConnectTLSNoVerify = cBit(0xC5)
)

const (
	// SelectorLastValid is the default selection that will keep using the last
	// Group unless it fails. On a failure (or the first call), this will act
	// similar to 'SelectorRoundRobin'.
	//
	// Takes effect only if there are multiple Groups in this Config.
	// This value is GLOBAL and can be present in any Group!
	SelectorLastValid = cBit(0xAA)
	// SelectorRoundRobin is a selection option that will simply select the NEXT
	// Group on every connection attempt. This option is affected by the Group
	// weights set on each addition and will prefer higher numbered options in
	// order.
	//
	// Takes effect only if there are multiple Groups in this Config.
	// This value is GLOBAL and can be present in any Group!
	SelectorRoundRobin = cBit(0xAB)
	// SelectorRandom is a selection option that will ignore all weights and order
	// and will select an entry from the list randomly.
	//
	// Takes effect only if there are multiple Groups in this Config.
	// This value is GLOBAL and can be present in any Group!
	SelectorRandom = cBit(0xAC)
	// SelectorSemiRoundRobin is a selection option that will potentially select
	// the NEXT Group dependent on a random (25%) chance on every connection
	// attempt. This option is affected by the Group weights set on each addition
	// and will prefer higher numbered options in order. Otherwise, the last
	// group used is kept.
	//
	// Takes effect only if there are multiple Groups in this Config.
	// This value is GLOBAL and can be present in any Group!
	SelectorSemiRoundRobin = cBit(0xAD)
	// SelectorSemiRandom is a selection option that will ignore all weights and
	// order and will select an entry from the list randomly dependent on a
	// random (25%) chance on every connection attempt. Otherwise, the last
	// group used is kept.
	//
	// Takes effect only if there are multiple Groups in this Config.
	// This value is GLOBAL and can be present in any Group!
	SelectorSemiRandom = cBit(0xAE)
)

const (
	DaySunday uint8 = 1 << iota
	DayMonday
	DayTuesday
	DayWednesday
	DayThursday
	DayFriday
	DaySaturday
	DayEveryday = 0
)

Day bitmask constants

const (
	// WrapHex is a Setting that enables the Hex Wrapper for the generated Profile.
	WrapHex = cBit(0xD0)
	// WrapZlib is a Setting that enables the ZLIB Wrapper for the generated Profile.
	WrapZlib = cBit(0xD1)
	// WrapGzip is a Setting that enables the GZIP Wrapper for the generated Profile.
	WrapGzip = cBit(0xD2)
	// WrapBase64 is a Setting that enables the Base64 Wrapper for the generated
	// Profile.
	WrapBase64 = cBit(0xD3)
)

const DefaultJitter uint8 = 10

DefaultJitter is the default Jitter value when the provided jitter value is negative.

const DefaultSleep = time.Duration(60) * time.Second

DefaultSleep is the default sleep Time when the provided sleep value is empty or negative.

const Separator = cBit(0xFA)

Separator is an entry that can be used to create Groups in Config instances.

It is recommended to use the 'AddGroup' functions instead, but this can be used to create more advanced Groupings.

const TransformB64 = cBit(0xE0)

TransformB64 is a Setting that enables the Base64 Transform for the generated Profile.

Variables

var (
	// ErrInvalidSetting is an error returned by the 'Profile' function if any
	// of the specified Settings are invalid or do contain valid information.
	//
	// The error returned will be a wrapped version of this error.
	ErrInvalidSetting = xerr.Sub("setting is invalid", 0x5D)
	// ErrMultipleTransforms is an error returned by the 'Profile' function if
	// more than one Transform Setting is attempted to be applied in the Config
	// Group.
	//
	// Unlike Wrappers, Transforms cannot be stacked.
	ErrMultipleTransforms = xerr.Sub("cannot add multiple transforms", 0x5E)
	// ErrMultipleConnections is an error returned by the 'Profile' function if more
	// than one Connection Hint Setting is attempted to be applied in the Config
	// Group.
	ErrMultipleConnections = xerr.Sub("cannot add multiple connections", 0x5F)
)

var (
	// ErrNotAListener is an error that can be returned by a call to a Profile's
	// 'Listen' function when that operation is disabled.
	ErrNotAListener = xerr.Sub("not a Listener", 0x47)
	// ErrNotAConnector is an error that can be returned by a call to a
	// Profile's 'Connect' function when that operation is disabled.
	ErrNotAConnector = xerr.Sub("not a Connector", 0x48)
)

Functions

func Bytes

func Bytes(s ...Setting) []byte

Bytes will combine the supplied settings into a byte slice that can be used as a Config or written to disk.

func JSON

func JSON(s ...Setting) ([]byte, error)

JSON will combine the supplied settings into a JSON payload and returned in a byte slice. This will return any validation errors during conversion.

Not valid when the 'nojson' tag is specified.

func Write

func Write(w io.Writer, s ...Setting) error

Write will combine the supplied settings into a byte slice that will be written to the supplied writer. Any errors during writing will be returned.

Types

type Accepter

type Accepter interface {
	Listen(context.Context, string) (net.Listener, error)
}

Accepter is an interface that can be used to create listening sockets.

This interface defines a single function that returns a listener based on an accept address string.

The supplied Context can be used to close the listening socket.

type Config

type Config []byte

Config is a raw binary representation of settings for a C2 Profile. This can be used to save/load Profiles from a file or network location.

func Pack

func Pack(s ...Setting) Config

Pack will combine the supplied settings into a Config instance.

func (*Config) Add

func (c *Config) Add(s ...Setting)

Add will append the raw data of the supplied Settings to this Config instance.

func (*Config) AddGroup

func (c *Config) AddGroup(s ...Setting)

AddGroup will append the supplied Settings to this Config. This will append the raw data Setting data to this Config with a separator, indicating a new Profile.

func (Config) Build

func (c Config) Build() (Profile, error)

Build will attempt to generate a 'c2.Profile' interface from this Config instance.

This function will return an 'ErrInvalidSetting' if any value in this Config instance is invalid or 'ErrMultipleConnections' if more than one connection is contained in this Config.

The similar error 'ErrMultipleTransforms' is similar to 'ErrMultipleConnections' but applies to Transforms, if more than one Transform is contained.

Multiple 'c2.Wrapper' instances will be combined into a 'c2.MultiWrapper' in the order they are found.

Other functions that may return errors on creation, like encryption wrappers for example, will stop the build process and will return that wrapped error.

func (Config) Bytes

func (c Config) Bytes() []byte

Bytes returns the byte version of this Config. This is the same as casting the Config instance as '[]byte(c)'.

func (Config) Group

func (c Config) Group(p int) Config

Group will attempt to extract the Config Group out of this Config based on its position. Attempts to modify this Config slice will NOT modify the resulting parent Config. Modifying the parent Config after extracting a Group may invalidate this Group.

This can be used in combination with 'Groups' to iterate over the Groups in this Config.

If supplied '-1', this Config returns itself.

func (Config) Groups

func (c Config) Groups() int

Groups returns the number of Groups included in this Config. This determines how many Profiles are contained in this Config and will be generated when built.

Returns zero on an empty Config.

func (Config) Len

func (c Config) Len() int

Len returns the length of this Config instance. This is the same as 'len(c)'.

func (Config) MarshalJSON

func (c Config) MarshalJSON() ([]byte, error)

MarshalJSON will attempt to convert the raw binary data in this Config instance into a JSON format.

The only error that may occur is 'ErrInvalidSetting' if an invalid setting or data value is encountered during conversion.

func (Config) String

func (c Config) String() string

String returns a string representation of the data included in this Config instance. Each separate setting will be seperated by commas.

func (*Config) UnmarshalJSON

func (c *Config) UnmarshalJSON(b []byte) error

UnmarshalJSON will attempt to convert the JSON data provided into this Config instance.

Errors during parsing or formatting will be returned along with the 'ErrInvalidSetting' error if parsed data contains invalid values.

func (Config) Validate

func (c Config) Validate() error

Validate is similar to the 'Build' function but will instead only validate that the supplied Config will build into a Profile without returning an error. The error returned (if not nil) will be the same as the error returned during a Build call.

This function will return an 'ErrInvalidSetting' if any value in this Config instance is invalid or 'ErrMultipleConnections' if more than one connection is contained in this Config.

The similar error 'ErrMultipleTransforms' is similar to 'ErrMultipleConnections' but applies to Transforms, if more than one Transform is contained.

Multiple 'c2.Wrapper' instances will be combined into a 'c2.MultiWrapper' in the order they are found.

Other functions that may return errors on creation, like encryption wrappers for example, will stop the build process and will return that wrapped error.

func (Config) Write

func (c Config) Write(w io.Writer) error

Write will attempt to write the contents of this Config instance to the specified Writer.

This function will return any errors that occurred during the write. This is a NOP if this Config is empty.

type Connector

type Connector interface {
	Connect(context.Context, string) (net.Conn, error)
}

Connector is an interface that can be used to connect to listening sockets.

This interface defines a single function that returns a Connected socket based on the connection string.

The supplied Context can be used to close the connecting socket or interrupt blocking connections.

type Group

type Group struct {
	// contains filtered or unexported fields
}

Group is a struct that allows for using multiple connections for a single Session.

Groups are automatically created when a Config is built into a Profile that contains multiple Profile 'Groups'.

func (*Group) Connect

func (g *Group) Connect(x context.Context, s string) (net.Conn, error)

Connect is a function that will preform a Connection attempt against the supplied address string. This function may return an error if a connection could not be made or if this Profile does not support Client-side connections.

It is recommended for implementations to implement using the passed Context to stop in-flight calls.

func (*Group) Jitter

func (g *Group) Jitter() int8

Jitter returns a value that represents a percentage [0-100] that will be taken into account by a Session in order to skew its connection timeframe.

The value zero (0) is used to signify that Jitter is disabled. Other values greater than one hundred (100) are ignored, as well as values below zero.

The special value '-1' indicates that this Profile does not set a Jitter value and to use the system default '10%'.

func (*Group) KillDate

func (g *Group) KillDate() (time.Time, bool)

KillDate returns a value that indicates the date and time when the Session will stop functioning.

If the supplied boolean is false, there is no 'KillDate' set.

func (*Group) Len

func (g *Group) Len() int

Len implements the 'sort.Interface' interface, this allows for a Group to be sorted.

func (*Group) Less

func (g *Group) Less(i, j int) bool

Less implements the 'sort.Interface' interface, this allows for a Group to be sorted.

func (*Group) Listen

func (g *Group) Listen(x context.Context, s string) (net.Listener, error)

Listen is a function that will attempt to create a listening connection on the supplied address string. This function may return an error if a listener could not be created or if this Profile does not support Server-side connections.

It is recommended for implementations to implement using the passed Context to stop running Listeners.

func (*Group) MarshalBinary

func (g *Group) MarshalBinary() ([]byte, error)

MarshalBinary allows the source of this Group to be retrieved to be reused again.

This function returns an error if the source is not available.

func (*Group) Next

func (g *Group) Next() (string, Wrapper, Transform)

Next is a function call that can be used to grab the Profile's current target along with the appropriate Wrapper and Transform.

Implementations of a Profile are recommend to ensure that this function does not affect how the Profile currently works until a call to 'Switch' as this WILL be called on startup of a Session.

func (*Group) Sleep

func (g *Group) Sleep() time.Duration

Sleep returns a value that indicates the amount of time a Session should wait before attempting communication again, modified by Jitter (if enabled).

Sleep MUST be greater than zero (0), any value that is zero or less is ignored and indicates that this profile does not set a Sleep value and will use the system default '60s'.

func (*Group) Swap

func (g *Group) Swap(i, j int)

Swap implements the 'sort.Interface' interface, this allows for a Group to be sorted.

func (*Group) Switch

func (g *Group) Switch(e bool) bool

Switch is function that will indicate to the caller if the 'Next' function needs to be called. Calling this function has the potential to advance the Profile group, if available.

The supplied boolean must be true if the last call to 'Connect' ot 'Listen' resulted in an error or if a forced switch if warranted. This indicates to the Profile is "dirty" and a switchover must be done.

It is recommended to call the 'Next' function after if the result of this function is true.

Static Profile variants may always return 'false' to prevent allocations.

func (*Group) TrustedKey

func (g *Group) TrustedKey(k data.PublicKey) bool

TrustedKey returns true if the supplied Server PublicKey is trusted. Empty PublicKeys will always return false.

This function returns true if no trusted PublicKey hashes are configured or the hash was found.

func (*Group) WorkHours

func (g *Group) WorkHours() *WorkHours

WorkHours returns a value that indicates when the Session should be active and communicate with the C2 Server. The returned struct can be used to determine which days the Session can connect.

If the returned value is nil, there are no Working hours restrictions.

type MultiWrapper

type MultiWrapper []Wrapper

MultiWrapper is an alias for an array of Wrappers.

This will preform the wrapper/unwrapping operations in the order of the array.

This is automatically created by some Profile instances when multiple Wrappers are present.

func (MultiWrapper) Unwrap

func (m MultiWrapper) Unwrap(r io.Reader) (io.Reader, error)

Unwrap satisfies the Wrapper interface.

func (MultiWrapper) Wrap

func (m MultiWrapper) Wrap(w io.WriteCloser) (io.WriteCloser, error)

Wrap satisfies the Wrapper interface.

type Profile

type Profile interface {
	Jitter() int8
	Switch(bool) bool
	Sleep() time.Duration
	WorkHours() *WorkHours
	KillDate() (time.Time, bool)
	TrustedKey(data.PublicKey) bool
	Next() (string, Wrapper, Transform)
	Connect(context.Context, string) (net.Conn, error)
	Listen(context.Context, string) (net.Listener, error)
}

Profile is an interface that defines a C2 connection.

This is used for setting the specifics that wil be used to listen by servers and for connections by clients.

func Build

func Build(s ...Setting) (Profile, error)

Build will combine the supplied settings and return a compiled Profile interface.

Validation or setting errors will be returned if they occur.

func File

func File(s string) (Profile, error)

File will attempt to read the file contents, parse the contents and return a compiled Profile interface.

Validation or setting errors will be returned if they occur or if any file I/O errors occur.

func Raw

func Raw(b []byte) (Profile, error)

Raw will parse the raw bytes and return a compiled Profile interface.

Validation or setting errors will be returned if they occur.

func Reader

func Reader(r io.Reader) (Profile, error)

Reader will attempt to read the reader data, parse the raw data and return a compiled Profile interface.

Validation or setting errors will be returned if they occur or if any I/O errors occur.

type Setting

type Setting interface {
	// contains filtered or unexported methods
}

Setting is an interface that represents a C2 Profile setting in binary form.

This can be used to generate a C2 Profile from binary data or write a Profile to a binary stream or JSON payload (if enabled).

func ConnectIP

func ConnectIP(p uint) Setting

ConnectIP will provide an IP connection setting to the generated Profile with the specified protocol number.

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

func ConnectMuTLS

func ConnectMuTLS(ver uint16, ca, pem, key []byte) Setting

ConnectMuTLS will provide a TLS connection setting to the generated Profile with the specified TLS config that will allow for a complete mTLS setup.

This can be used for Listeners and Connectors, but the CA PEM data provided MUST be able to validate the client certificates, otherwise connections will fail.

Using the version value '0' will use the system default (same as the ConnectTLS option). Empty PEM blocks will render and error on build.

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

func ConnectTLSCerts

func ConnectTLSCerts(ver uint16, pem, key []byte) Setting

ConnectTLSCerts will provide a TLS connection setting to the generated Profile with the specified TLS config that will allow for a Listener to use the specified PEM and Private Key data in PEM format for listening.

This will also work as a Connector and can use the specified certificate for TLS authentication.

Using the version value '0' will use the system default (same as the ConnectTLS option). Empty PEM blocks will render and error on build.

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

func ConnectTLSEx

func ConnectTLSEx(ver uint16) Setting

ConnectTLSEx will provide a TLS connection setting to the generated Profile with the specified TLS minimum version specified. Using the version value '0' will use the system default (same as the ConnectTLS option).

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

This hint cannot be used as a Listener.

func ConnectTLSExCA

func ConnectTLSExCA(ver uint16, ca []byte) Setting

ConnectTLSExCA will provide a TLS connection setting to the generated Profile with the specified TLS minimum version and will use the specified PEM bytes as the Root CA to trust when connecting.

Using the version value '0' will use the system default (same as the ConnectTLS option). Empty PEM blocks will default to system root CAs.

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

This hint cannot be used as a Listener.

func ConnectWC2

func ConnectWC2(url, host, agent string, headers map[string]string) Setting

ConnectWC2 will provide a WebC2 connection setting to the generated Profile with the specified User-Agent, URL and Host Matcher strings (strings can be empty).

If multiple connections are contained in the current Config Group, a 'ErrMultipleConnections' error will be returned during a build.

This hint cannot be used as a Listener.

func Host

func Host(s string) Setting

Host will return a Setting that will specify a host setting to the profile. If empty, this value is ignored.

This may be included multiple times to add multiple Host entries to be used in a single Group entry.

func Jitter

func Jitter(n uint) Setting

Jitter returns a Setting that will specify the Jitter setting of the generated Profile. Only Jitter values from zero to one-hundred [0-100] are valid.

Other values are ignored and replaced with the default.

func KeyPin

func KeyPin(k data.PublicKey) Setting

KeyPin returns a Setting that indicates to the client if the Server's PublicKey should be trusted. This Setting can be added multiple times to add multiple PublicKeys.

This function takes a trusted PublicKey and hashes it to be matched by the client.

func KillDate

func KillDate(t time.Time) Setting

KillDate returns a Setting that will specify the KillDate setting of the generated Profile. Zero values will clear the set value.

func Sleep

func Sleep(t time.Duration) Setting

Sleep returns a Setting that will specify the Sleep timeout setting of the generated Profile. Values of zero and below are ignored.

func TransformB64Shift

func TransformB64Shift(s int) Setting

TransformB64Shift returns a Setting that will apply the Base64 Shift Transform to the generated Profile. The specified number will be the shift index of the Transform.

If a Transform Setting is already contained in the current Config Group, a 'ErrMultipleTransforms' error will be returned when the 'Profile' function is called.

func TransformDNS

func TransformDNS(n ...string) Setting

TransformDNS returns a Setting that will apply the DNS Transform to the generated Profile. If any DNS Domains are specified, they will be used in the Transform.

If a Transform Setting is already contained in the current Config Group, a 'ErrMultipleTransforms' error will be returned when the 'Profile' function is called.

func Weight

func Weight(w uint) Setting

Weight returns a Setting that will specify the Weight of the generated Profile. Weight is taken into account when multiple Profiles are included to make a multi-profile.

This option MUST be included in the Group to take effect. Not including this will set the value to zero (0). Multiple values in a Group will take the last value.

func WrapAES

func WrapAES(k, iv []byte) Setting

WrapAES returns a Setting that will apply the AES Wrapper to the generated Profile. The specified key and IV will be the AES Key and IV used.

func WrapCBK

func WrapCBK(a, b, c, d byte) Setting

WrapCBK returns a Setting that will apply the CBK Wrapper to the generated Profile. The specified ABC and Type values are the CBK letters used.

To specify the CBK buffer size, use the 'WrapCBKSize' function instead.

func WrapCBKSize

func WrapCBKSize(s, a, b, c, d byte) Setting

WrapCBKSize returns a Setting that will apply the CBK Wrapper to the generated Profile. The specified Size, ABC and Type values and the CBK size and letters used.

func WrapXOR

func WrapXOR(k []byte) Setting

WrapXOR returns a Setting that will apply the XOR Wrapper to the generated Profile. The specified key will be the XOR key used.

type Static

type Static struct {

	// W is the Wrapper
	W Wrapper
	// T is the Transform
	T Transform
	// L is the Acceptor or Server Listener Connector
	L Accepter
	// C is the Connector or Client Connector
	C Connector
	// K is the KillDate
	K *time.Time
	// A is the WorHours
	A *WorkHours
	// H is the Target Host or Listen Address
	H string
	// P is the valid Server PublicKeys that can be used as FNV-32 hashes
	P []uint32
	// S is the Sleep duration
	S time.Duration
	// J is the Jitter percentage
	J int8
	// contains filtered or unexported fields
}

Static is a simple static Profile implementation.

This struct fills all the simple values for a Profile without anything Fancy.

The single letter attributes represent the values that are used.

If 'S' or 'J' are omitted or zero values, they will be replaced with the DefaultJitter and DefaultSleep values respectively.

If the 'L' or 'C' values are omitted or nil, they will disable that function of this Profile.

func (Static) Connect

func (s Static) Connect(x context.Context, a string) (net.Conn, error)

Connect is a function that will preform a Connection attempt against the supplied address string.

This function may return an error if a connection could not be made or if this Profile does not support Client-side connections.

It is recommended for implementations to implement using the passed Context to stop in-flight calls.

func (Static) Jitter

func (s Static) Jitter() int8

Jitter fulfils the Profile interface.

func (Static) KillDate

func (s Static) KillDate() (time.Time, bool)

KillDate fulfils the Profile interface.

A valid or empty time.Time value along with a True will indicate that this Profile has a KillDate set. If the boolean is false, this indicates that no KilDate is specified in this Profile and the 'time.Time' will be ignored.

func (Static) Listen

func (s Static) Listen(x context.Context, a string) (net.Listener, error)

Listen is a function that will attempt to create a listening connection on the supplied address string.

This function may return an error if a listener could not be created or if this Profile does not support Server-side connections.

It is recommended for implementations to implement using the passed Context to stop running Listeners.

func (Static) Next

func (s Static) Next() (string, Wrapper, Transform)

Next is a function call that can be used to grab the Profile's current target along with the appropriate Wrapper and Transform.

Implementations of a Profile are recommend to ensure that this function does not affect how the Profile currently works until a call to 'Switch' as this WILL be called on startup of a Session.

func (Static) Sleep

func (s Static) Sleep() time.Duration

Sleep returns a value that indicates the amount of time a Session should wait before attempting communication again, modified by Jitter (if enabled).

Sleep MUST be greater than zero (0), any value that is zero or less is ignored and indicates that this profile does not set a Sleep value and will use the system default '60s'.

func (Static) Switch

func (Static) Switch(_ bool) bool

Switch is function that will indicate to the caller if the 'Next' function needs to be called. Calling this function has the potential to advance the Profile group, if available.

The supplied boolean must be true if the last call to 'Connect' ot 'Listen' resulted in an error or if a forced switch if warranted. This indicates to the Profile is "dirty" and a switchover must be done.

It is recommended to call the 'Next' function after if the result of this function is true.

Static Profile variants may always return 'false' to prevent allocations.

func (Static) TrustedKey

func (s Static) TrustedKey(k data.PublicKey) bool

TrustedKey returns true if the supplied Server PublicKey is trusted. Empty PublicKeys will always return false.

This function returns true if no trusted PublicKey hashes are configured or the hash was found.

func (Static) WorkHours

func (s Static) WorkHours() *WorkHours

WorkHours fulfils the Profile interface. Empty WorkHours values indicate that there is no workhours set and a nil value indicates that there is no WorkHours in this Profile.

type Transform

type Transform interface {
	Read([]byte, io.Writer) error
	Write([]byte, io.Writer) error
}

Transform is an interface that can modify the data BEFORE it is written or AFTER is read from a Connection.

Transforms may be used to mask and unmask communications as benign protocols such as DNS, FTP or HTTP.

type WorkHours

type WorkHours struct {
	// Days is a bitmask of the days that this WorkHours struct allows us to work
	// on. The bit values are 0 (Sunday) to 7 (Saturday). Values 0, 255 and anything
	// over 126 are treated as all days selected.
	Days uint8
	// StartHour is the 0-23 value of the hour that this WorkHours struct allows
	// us to work on. If this value is greater than 23, an error will be returned
	// when attempting to use it.
	//
	// If this value and StartMin are zero, the WorkHours will start after midnight
	// of the next day (if Day or EndHour and EndMin are set).
	StartHour uint8
	// StartMin is the 0-59 value of the minute that this WorkHours struct allows
	// us to work on. If this value is greater than 59, an error will be returned
	// when attempting to use it.
	//
	// If this value and StartHour are zero, the WorkHours will start after midnight
	// of the next day (if Day or EndHour and EndMin are set).
	StartMin uint8
	// EndHour is the 0-23 value of the hour that this WorkHours struct stops us
	// from working. If this value is greater than 23, an error will be returned
	// when attempting to use it.
	//
	// If this value and EndMin are zero, the WorkHours will continue unchanged.
	EndHour uint8
	// EndMin is the 0-59 value of the minute that this WorkHours struct stops us
	// from working. If this value is greater than 59, an error will be returned
	// when attempting to use it.
	//
	// If this value and EndHour are zero, the WorkHours will continue unchanged.
	EndMin uint8
}

WorkHours is a struct that can be used to indicate to a Session when it should and shouldn't operate. When a WorkHours struct is set, a Session will check it before operating and will wait until the next set timeslot (depending on WorkHours values).

This struct is also compatible with the Setting interface and can be used directly in Pack or Build functions.

Using this in a Pack or Build function when it is empty will clear an other previous and/or set WorkHours values.

func (WorkHours) Empty

func (w WorkHours) Empty() bool

Empty returns true if this WorkHours struct is considered empty as nothing is set and all values are zero, false otherwise.

func (WorkHours) MarshalStream

func (w WorkHours) MarshalStream(s data.Writer) error

MarshalStream writes the data for this WorkHours struct to the supplied Writer.

func (WorkHours) String

func (w WorkHours) String() string

String returns the string version of the WorkHours.Day value. This can be parsed back into the numerical version.

func (*WorkHours) UnmarshalStream

func (w *WorkHours) UnmarshalStream(r data.Reader) error

UnmarshalStream transforms this struct from a binary format that is read from

func (WorkHours) Verify

func (w WorkHours) Verify() error

Verify checks the values set in this WorkHours struct and returns any errors due to the number/time values being invalid.

func (WorkHours) Work

func (w WorkHours) Work() time.Duration

Work returns the time that should be waitied for this WorkHours to be active. If zero, then this means that the WorkHours applies currently and work can be done.

This function will not return no more than time to reach the next day.

type Wrapper

type Wrapper interface {
	Unwrap(io.Reader) (io.Reader, error)
	Wrap(io.WriteCloser) (io.WriteCloser, error)
}

Wrapper is an interface that wraps the binary streams into separate stream types. This allows for using encryption or compression (or both!).