injector

Documentation

Index

• Constants
• Variables
• func GenerateGhostTextPNG(text string, width, height int) ([]byte, error)
• func InjectAlphaStego(img *image.NRGBA, secretText string)
• func InjectByExtension(filename string, data []byte, payload string, strategies map[string]string) ([]byte, error)
• func InjectDOCX(data []byte, payload string) ([]byte, error)
• func InjectGIF(data []byte, payload string) ([]byte, error)
• func InjectGIFJS(gifData []byte, jsPayload string) ([]byte, error)
• func InjectICS(content []byte, payload string) ([]byte, error)
• func InjectJPEG(data []byte, payload string) ([]byte, error)
• func InjectJS(data []byte, payload string) ([]byte, error)
• func InjectJSON(data []byte, payload string) ([]byte, error)
• func InjectMP3(data []byte, payload string) ([]byte, error)
• func InjectPDF(data []byte, payload string) ([]byte, error)
• func InjectPDFHTML(pdfData []byte, htmlPayload string) ([]byte, error)
• func InjectPNG(data []byte, payload string) ([]byte, error)
• func InjectPNGAlphaStego(data []byte, payload string) ([]byte, error)
• func InjectRobots(data []byte, payload string) ([]byte, error)
• func InjectSRT(content []byte, payload string) ([]byte, error)
• func InjectSVGFont(content []byte, payload string) ([]byte, error)
• func InjectTTF(data []byte, payload string) ([]byte, error)
• func InjectWAV(data []byte, payload string) ([]byte, error)
• func InjectWOFF2(data []byte, payload string) ([]byte, error)
• func InjectXLSX(data []byte, payload string) ([]byte, error)
• func InjectXML(data []byte, payload string) ([]byte, error)
• func RevealAlphaStego(img *image.NRGBA) string
• func ValidateSVG(content []byte) error
• type InjectorFunc
  • func GetInjector(filename string, strategies map[string]string) InjectorFunc
• type ResolverFunc

Constants

const (
	SigRIFF = "RIFF"
	SigWAVE = "WAVE"
	SigGIF  = "GIF"
)

File Signatures

const (
	ChunkICMT = "ICMT"
	ChunkINFO = "INFO"
	ChunkLIST = "LIST"

	ChunkIEND = "IEND"
	ChunkTEXT = "tEXt"

	JpegMarkerCOM = 0xFFFE

	GifExtIntroducer = 0x21
	GifLabelComment  = 0xFE
	GifTrailer       = 0x3B
)

Chunk Types & Markers

Variables

var (
	SigPNG  = []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A}
	SigJPEG = []byte{0xFF, 0xD8} // SOI
)

Functions

func GenerateGhostTextPNG

func GenerateGhostTextPNG(text string, width, height int) ([]byte, error)

GenerateGhostTextPNG creates a PNG where the text is written in pure color (e.g., Red or White) but the Alpha channel is set to 0. This implements Vector B: The Premultiplication Exploit.

func InjectAlphaStego

func InjectAlphaStego(img *image.NRGBA, secretText string)

InjectAlphaStego modifies the Least Significant Bits (LSB) of the Alpha channel to encode a secret string. This implements Vector C: Alpha-Steganography. Note: This function modifies the image in-place.

func InjectByExtension

func InjectByExtension(filename string, data []byte, payload string, strategies map[string]string) ([]byte, error)

InjectByExtension dispatches the injection based on file extension and configuration.

func InjectDOCX

func InjectDOCX(data []byte, payload string) ([]byte, error)

InjectDOCX injects a hidden paragraph using godocx library.

func InjectGIF

func InjectGIF(data []byte, payload string) ([]byte, error)

InjectGIF injects a Comment Extension block before the Trailer.

func InjectGIFJS

func InjectGIFJS(gifData []byte, jsPayload string) ([]byte, error)

InjectGIFJS appends a JavaScript payload to the end of a GIF file. This creates a "GIFAR" style polyglot where the file is a valid image, but can be executed as a script in some contexts (e.g. <script src="...") or detected by scanners looking for JS.

func InjectICS

func InjectICS(content []byte, payload string) ([]byte, error)

InjectICS injects a payload into the DESCRIPTION field of an ICS calendar file.

func InjectJPEG

func InjectJPEG(data []byte, payload string) ([]byte, error)

InjectJPEG injects a COM (Comment) segment after SOI.

func InjectJS

func InjectJS(data []byte, payload string) ([]byte, error)

InjectJS injects a variable declaration at the top or bottom.

func InjectJSON

func InjectJSON(data []byte, payload string) ([]byte, error)

InjectJSON injects a key "_llm_instruction" with the payload.

func InjectMP3

func InjectMP3(data []byte, payload string) ([]byte, error)

InjectMP3 injects a payload into the ID3v2 USLT (Lyrics) frame. It enforces the Round-Trip Rule by parsing, modifying, and verifying.

func InjectPDF

func InjectPDF(data []byte, payload string) ([]byte, error)

InjectPDF injects an invisible watermark into a PDF. Satisfies Round-Trip Rule: pdfcpu handles parsing and XREF rebuilding.

func InjectPDFHTML

func InjectPDFHTML(pdfData []byte, htmlPayload string) ([]byte, error)

InjectPDFHTML appends an HTML payload to the end of a PDF file. The file remains a valid PDF (readers stop at %%EOF), but contains HTML that might be parsed by naive scrapers or LLMs reading the file as text.

func InjectPNG

func InjectPNG(data []byte, payload string) ([]byte, error)

InjectPNG injects a tEXt chunk with the payload. Satisfies Round-Trip Rule: We construct a valid chunk with CRC.

func InjectPNGAlphaStego

func InjectPNGAlphaStego(data []byte, payload string) ([]byte, error)

InjectPNGAlphaStego is the adapter function for the dispatcher. It decodes a PNG, injects the payload into the alpha channel LSB, and re-encodes.

func InjectRobots

func InjectRobots(data []byte, payload string) ([]byte, error)

InjectRobots injects a Disallow rule or comment.

func InjectSRT

func InjectSRT(content []byte, payload string) ([]byte, error)

InjectSRT injects a 1ms subtitle block at the beginning.

func InjectSVGFont

func InjectSVGFont(content []byte, payload string) ([]byte, error)

InjectSVGFont injects a payload into the <desc> or <metadata> tag of an SVG font.

func InjectTTF

func InjectTTF(data []byte, payload string) ([]byte, error)

InjectTTF injects a payload into the Name Table (ID 10 or 13).

func InjectWAV

func InjectWAV(data []byte, payload string) ([]byte, error)

InjectWAV injects a payload into a new 'ICMT' (Comment) chunk within a 'LIST' 'INFO' chunk. This requires low-level RIFF parsing to ensure we update the main chunk size.

func InjectWOFF2

func InjectWOFF2(data []byte, payload string) ([]byte, error)

InjectWOFF2 injects a payload into the WOFF2 Extended Metadata Block.

func InjectXLSX

func InjectXLSX(data []byte, payload string) ([]byte, error)

InjectXLSX injects a VeryHidden sheet containing the payload.

func InjectXML

func InjectXML(data []byte, payload string) ([]byte, error)

InjectXML injects a comment into the XML.

func RevealAlphaStego

func RevealAlphaStego(img *image.NRGBA) string

RevealAlphaStego extracts the secret string from the Alpha channel LSBs. It reads until it finds a null terminator (0x00) or runs out of pixels.

func ValidateSVG

func ValidateSVG(content []byte) error

ValidateSVG ensures the SVG is valid XML.

Types

type InjectorFunc

type InjectorFunc func(data []byte, payload string) ([]byte, error)

InjectorFunc defines the signature for injection functions.

func GetInjector

func GetInjector(filename string, strategies map[string]string) InjectorFunc

GetInjector returns the appropriate injection function for the given filename/extension. It checks the strategies map for specific overrides (e.g. "polyglot").

type ResolverFunc

type ResolverFunc func(filename, strategy string) InjectorFunc

ResolverFunc defines the logic to select an InjectorFunc based on context.