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Added support for generating an entropy curve based on the input data

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This commit is contained in:
mshwed 2019-04-06 15:59:36 -04:00
parent c80cb57b07
commit f988a958bb
1 changed files with 81 additions and 9 deletions
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90
src/core/operations/AdvancedEntropy.mjs
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@ -34,7 +34,7 @@ class AdvancedEntropy extends Operation {
{
"name": "Visualization",
"type": "option",
"value": ["Histogram (Bar)", "Histogram (Line)"]
"value": ["Histogram (Bar)", "Histogram (Line)", "Curve"]
}
];
}
@ -66,6 +66,26 @@ class AdvancedEntropy extends Operation {
return -entropy;
}
/**
*
* @param inputBytes
* @returns {entropyData}
*/
calculateScanningEntropy(inputBytes) {
let entropyData = [];
let binSelection = Math.ceil(inputBytes.length / 256);
let binWidth = binSelection < 256 ? 256 : binSelection;
for (let bytePos = 0; bytePos < inputBytes.length; bytePos+=binWidth) {
const block = inputBytes.slice(bytePos, bytePos+binWidth)
const blockEntropy = this.calculateShannonEntropy(block);
entropyData.push(blockEntropy);
}
return { entropyData, binWidth };
}
/**
* Calculates the frequency of bytes in the input.
*
@ -75,9 +95,11 @@ class AdvancedEntropy extends Operation {
* @param {integer} svgHeight
* @param {integer} svgWidth
* @param {object} margins
* @param {string} xTitle
* @param {string} yTitle
* @returns {undefined}
*/
createHistogramAxes(svg, xScale, yScale, svgHeight, svgWidth, margins) {
createAxes(svg, xScale, yScale, svgHeight, svgWidth, margins, title, xTitle, yTitle) {
// Axes
const yAxis = d3.axisLeft()
.scale(yScale);
@ -100,18 +122,18 @@ class AdvancedEntropy extends Operation {
.attr("x", 0 - (svgHeight / 2))
.attr("dy", "1em")
.style("text-anchor", "middle")
.text("Frequency (%)")
.text(yTitle)
svg.append("text")
.attr("transform", `translate(${svgWidth / 2}, ${svgHeight - margins.bottom + 40})`)
.style("text-anchor", "middle")
.text("Byte")
.text(xTitle)
// Add title
svg.append("text")
.attr("transform", `translate(${svgWidth / 2}, ${margins.top - 10})`)
.style("text-anchor", "middle")
.text("Byte Frequency")
.text(title)
}
/**
@ -175,11 +197,10 @@ class AdvancedEntropy extends Operation {
svg.append('path')
.datum(byteFrequency)
.attr("class", "line")
.attr("d", line)
.attr("fill", "steelblue");
this.createHistogramAxes(svg, xScale, yScale, svgHeight, svgWidth, margins);
this.createAxes(svg, xScale, yScale, svgHeight, svgWidth, margins, "", "Byte", "Byte Frequency");
return svg._groups[0][0].outerHTML;
}
@ -223,7 +244,57 @@ class AdvancedEntropy extends Operation {
.attr("height", dataPoint => yScale(0) - yScale(dataPoint))
.attr("fill", "blue");
this.createHistogramAxes(svg, xScale, yScale, svgHeight, svgWidth, margins);
this.createAxes(svg, xScale, yScale, svgHeight, svgWidth, margins, "", "Byte", "Byte Frequency");
return svg._groups[0][0].outerHTML;
}
/**
* Creates a byte frequency histogram
*
* @param {byteArray} input
* @param {number} blockSize
* @returns {HTML}
*/
createEntropyCurve(input) {
const { entropyData, binWidth } = this.calculateScanningEntropy(input);
const svgWidth = 500,
svgHeight = 500;
const document = new nodom.Document();
let svg = document.createElement("svg");
svg = d3.select(svg)
.attr("width", "100%")
.attr("height", "100%")
.attr("viewBox", `0 0 ${svgWidth} ${svgHeight}`);
const margins = {top: 30, right: 20, bottom: 50, left: 30};
const yScale = d3.scaleLinear()
.domain([0, d3.max(entropyData, d => d)])
.range([svgHeight - margins.bottom, margins.top]);
const xScale = d3.scaleLinear()
.domain([0, entropyData.length])
.range([margins.left, svgWidth - margins.right]);
const line = d3.line()
.x((d, i) => { return xScale(i)})
.y((d) => { return yScale(d)})
.curve(d3.curveMonotoneX);
if (entropyData.length > 0 ) {
svg.append('path')
.datum(entropyData)
.attr("d", line);
svg.selectAll("path").attr("fill", "none").attr("stroke", "steelblue");
}
this.createAxes(svg, xScale, yScale, svgHeight, svgWidth, margins, "Scanning Entropy" , `Block (${binWidth}B)`, "Entropy");
console.log('TEST', entropyData);
return svg._groups[0][0].outerHTML;
}
@ -244,7 +315,8 @@ class AdvancedEntropy extends Operation {
let svgData;
if (visualizationType === "Histogram (Bar)") svgData = this.createByteFrequencyBarHistogram(entropyData);
else if (visualizationType === "Histogram (Line)") svgData = this.createByteFrequencyLineHistogram(entropyData);
else if (visualizationType === "Curve") svgData = this.createEntropyCurve(input);
return svgData;
}
}