refactor code

hexdump.js

@@ -0,0 +1,105 @@
+// hacked hexdump from frida to work on normal ArrayBuffers
+import "./shim.ts";
+export const hexdump = (target, options) => {
+  options = options || {};
+
+  const startOffset = options.offset || 0;
+  let length = options.length;
+  const showHeader = options.hasOwnProperty("header") ? options.header : true;
+  const useAnsi = options.hasOwnProperty("ansi") ? options.ansi : false;
+  const ansiColor = options.hasOwnProperty("ansiColor") ? options.ansiColor : 0;
+
+  let buffer;
+  if (target instanceof ArrayBuffer) {
+    if (length === undefined) length = target.byteLength;
+    else length = Math.min(length, target.byteLength);
+    buffer = target;
+  } else {
+    throw "Gimme array buffer";
+  }
+
+  const startAddress = 0;
+  const endAddress = target.byteLength;
+
+  const bytes = new Uint8Array(buffer);
+
+  const columnPadding = "  ";
+  const leftColumnWidth = Math.max(endAddress.toString(16).length, 8);
+  const hexLegend = " 0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F";
+  const asciiLegend = "0123456789ABCDEF";
+
+  let resetColor, offsetColor, dataColor, newlineColor;
+  if (useAnsi) {
+    resetColor = "\x1b[0m";
+    offsetColor = "\x1b[0;32m";
+    dataColor = ansiColor == 0 ? "\x1b[0;33m" : "\x1b[0;34m";
+    newlineColor = resetColor;
+  } else {
+    resetColor = "";
+    offsetColor = "";
+    dataColor = "";
+    newlineColor = "";
+  }
+
+  const result = [];
+
+  if (showHeader) {
+    result.push(pad("        ", leftColumnWidth, " "), columnPadding, hexLegend, columnPadding, asciiLegend, "\n");
+  }
+
+  let offset = startOffset;
+  for (let bufferOffset = 0; bufferOffset < length; bufferOffset += 16) {
+    if (bufferOffset !== 0) result.push("\n");
+
+    result.push(
+      offsetColor,
+      pad((startAddress + offset).toString(16), leftColumnWidth, "0"),
+      resetColor,
+      columnPadding,
+    );
+
+    const asciiChars = [];
+    const lineSize = Math.min(length - offset, 16);
+
+    for (let lineOffset = 0; lineOffset !== lineSize; lineOffset++) {
+      const value = bytes[offset++];
+
+      const isNewline = value === 10;
+
+      const hexPair = pad(value.toString(16), 2, "0");
+      if (lineOffset !== 0) result.push(" ");
+      result.push(isNewline ? newlineColor : dataColor, hexPair, resetColor);
+
+      asciiChars.push(
+        isNewline ? newlineColor : dataColor,
+        value >= 32 && value <= 126 ? String.fromCharCode(value) : ".",
+        resetColor,
+      );
+    }
+
+    for (let lineOffset = lineSize; lineOffset !== 16; lineOffset++) {
+      result.push("   ");
+      asciiChars.push(" ");
+    }
+
+    result.push(columnPadding);
+
+    Array.prototype.push.apply(result, asciiChars);
+  }
+
+  let trailingSpaceCount = 0;
+  for (let tailOffset = result.length - 1; tailOffset >= 0 && result[tailOffset] === " "; tailOffset--) {
+    trailingSpaceCount++;
+  }
+
+  return result.slice(0, result.length - trailingSpaceCount).join("");
+};
+
+function pad(str, width, fill) {
+  const result = [];
+  const paddingSize = Math.max(width - str.length, 0);
+  for (let index = 0; index !== paddingSize; index++) {
+    result.push(fill);
+  }
+  return result.join("") + str;
+}