@shockpkg/dir-projector/lib/patcher.mjs

Package for creating Shockwave Director projectors

import fse from 'fs-extra';

/**
 * Converts a hex string into a series of byte values, with unknowns being null.
 *
 * @param str Hex string.
 * @returns Bytes and null values.
 */
function patchHexToBytes(str) {
  return (str.replace(/[\s\r\n]/g, '').match(/.{1,2}/g) || []).map(s => {
    if (s.length !== 2) {
      throw new Error('Internal error');
    }

    return /[0-9A-F]{2}/i.test(s) ? parseInt(s, 16) : null;
  });
}
/* eslint-disable no-multi-spaces */

/* eslint-disable line-comment-position */

/* eslint-disable no-inline-comments */
// A list of patch candidates, made to be partially position independant.
// Basically these patches just increase the temporary buffer sizes.
// Enough to provide amply room for anything that should be in the registry.
// Sizes 0x10000 for ASCII, and 0x20000 for WCHAR.
// Not enough room to calculate the correct size, and use it directly.


const patchWindowsS3dInstalledDisplayDriversSizePatches = [// director-8.5.0 - director-11.0.0-hotfix-1:
{
  find: patchHexToBytes(['FF 15 -- -- -- --', // call    DWORD PTR ds:-- -- -- --
  'BE 04 01 00 00', // mov     esi, 0x104
  '56', // push    esi
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' ')),
  replace: patchHexToBytes(['FF 15 -- -- -- --', // call    DWORD PTR ds:-- -- -- --
  // Change:
  'BE 00 00 01 00', // mov     esi, 0x10000
  '56', // push    esi
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' '))
}, // director-11.0.0-hotfix-3 - director-11.5.0:
{
  find: patchHexToBytes(['FF 15 -- -- -- --', // call    DWORD PTR ds:-- -- -- --
  'BF 04 01 00 00', // mov     edi, 0x104
  '57', // push    edi
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' ')),
  replace: patchHexToBytes(['FF 15 -- -- -- --', // call    DWORD PTR ds:-- -- -- --
  // Change:
  'BF 00 00 01 00', // mov     edi, 0x10000
  '57', // push    edi
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' '))
}, // director-11.5.8 - director-11.5.9:
{
  find: patchHexToBytes(['68 -- -- -- --', // push    -- -- -- --
  '57', // push    edi
  'FF D6', // call    esi
  '68 08 02 00 00', // push    0x208
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' ')),
  replace: patchHexToBytes(['68 -- -- -- --', // push    -- -- -- --
  '57', // push    edi
  'FF D6', // call    esi
  // Change:
  '68 00 00 02 00', // push    0x20000
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' '))
}, // director-12.0.0:
{
  find: patchHexToBytes(['68 -- -- -- --', // push    -- -- -- --
  '53', // push    ebx
  'FF D7', // call    edi
  '68 08 02 00 00', // push    0x208
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' ')),
  replace: patchHexToBytes(['68 -- -- -- --', // push    -- -- -- --
  '53', // push    ebx
  'FF D7', // call    edi
  // Change:
  '68 00 00 02 00', // push    0x20000
  'E8 -- -- -- --' // call    -- -- -- --
  ].join(' '))
}];
/* eslint-enable no-multi-spaces */

/* eslint-enable line-comment-position */

/* eslint-enable no-inline-comments */

/**
 * Patch data buffer once.
 *
 * @param data Data buffer.
 * @param candidates Patch candidates.
 * @param name Patch name.
 */

function patchDataOnce(data, candidates, name) {
  // Search the buffer for patch candidates.
  let foundOffset = -1;
  let foundPatch = [];

  for (const patch of candidates) {
    const {
      find,
      replace
    } = patch;

    if (replace.length !== find.length) {
      throw new Error('Internal error');
    }

    const end = data.length - find.length;

    for (let i = 0; i < end; i++) {
      let found = true;

      for (let j = 0; j < find.length; j++) {
        const b = find[j];

        if (b !== null && data[i + j] !== b) {
          found = false;
          break;
        }
      }

      if (!found) {
        continue;
      }

      if (foundOffset !== -1) {
        throw new Error(`Multiple patch candidates found for: ${name}`);
      } // Remember patch to apply.


      foundOffset = i;
      foundPatch = replace;
    }
  }

  if (foundOffset === -1) {
    throw new Error(`No patch candidates found for: ${name}`);
  } // Apply the patch to the buffer, and write to file.


  for (let i = 0; i < foundPatch.length; i++) {
    const b = foundPatch[i];

    if (b !== null) {
      data[foundOffset + i] = b;
    }
  }
}
/**
 * Patch a file once.
 *
 * @param file File path.
 * @param candidates Patch candidates.
 * @param name Patch name.
 */


async function patchFileOnce(file, candidates, name) {
  const data = await fse.readFile(file);
  patchDataOnce(data, candidates, name);
  await fse.writeFile(file, data);
}
/**
 * Patch Windows Shockwave 3D InstalledDisplayDrivers size.
 *
 * @param file File path.
 */


export async function patchWindowsS3dInstalledDisplayDriversSize(file) {
  await patchFileOnce(file, patchWindowsS3dInstalledDisplayDriversSizePatches, 'Windows Shockwave 3D InstalledDisplayDrivers Size');
}
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