Transform LCP/LCPL files to regular EPUB/PDF/ZIP

lcp_download.php

#!/usr/bin/php
<?php
// Note: this code does not contain any DRM removal, DRM removal is made by https://notabug.org/NewsGuyTor/DeDRM_tools-LCP
//
// Install steps:
// Debian/Ubuntu/Mint: apt install php-cli python3 python3-cryptodome python3-lxml zip unzip
//
// How to use?
// Just run: php lcp_download.php FILE.LCPL PASSWORD
// A new FILE_decrypted.epub will be created in the same directory


$argv = $_SERVER['argv'] ?? [];

if (count($argv) < 3) {
	printf("Usage: %s EPUB_OR_LCPL_FILE PASSWORD\n", $argv[0]);
	exit(1);
}

if (!shell_exec('which python3')) {
	echo "python3 binary not found";
	exit(1);
}

if (!shell_exec('which unzip')) {
	echo "unzip binary not found";
	exit(1);
}

$in = $argv[1];
$out = preg_replace('/\.[^\.]+?$/', '', $in);
$out .= '_decrypted';
$password = $argv[2];

$fp = fopen($argv[1], 'rb');
$is_zip = fread($fp, 4) == "PK\003\004";
fclose($fp);

$license_url = null;

// .lcpl file
if (!$is_zip && preg_match('/\.lcpl$/i', $in)) {
	$data = json_decode(file_get_contents($in));

	if (!isset($data->links)) {
		echo "Could not download EPUB: invalid LCPL file?\n";
		exit(1);
	}

	$url = null;

	foreach ($data->links as $link) {
		if ($link->rel == 'publication') {
			$url = $link->href;
		}
		elseif ($link->rel == 'status') {
			$license_url = $link->href;
		}
	}

	if (!$url) {
		echo "Could not download EPUB: no publication URL was found?\n";
		exit(1);
	}

	printf("Downloading ebook from %s...\n", $url);
	$in = tempnam(sys_get_temp_dir(), 'dedrm');
	copy($url, $in);
}

$has_license = shell_exec(sprintf('unzip -l %s | fgrep license.lcp', escapeshellarg($in)));

if (!$has_license) {
	if (!$license_url) {
		echo "License file 'license.lcp' is missing?!\n";
		exit(1);
	}

	if (!$is_zip) {
		echo "Cannot append license to non-EPUB file\n";
		exit(1);
	}

	if (!shell_exec('which zip')) {
		echo "zip binary not found";
		exit(1);
	}

	printf("Downloading license from %s...\n", $license_url);

	$tmpdir = sys_get_temp_dir() . DIRECTORY_SEPARATOR . 'dedrm-' . sha1(random_bytes(10));
	mkdir($tmpdir);
	mkdir($tmpdir . '/META-INF');

	copy($license_url, $tmpdir . DIRECTORY_SEPARATOR . 'META-INF/license.lcpl');

	printf("Appending license to EPUB file...\n");
	passthru(sprintf('cd %s && zip -g %s %s && rm -rf %1$s',
		escapeshellarg($tmpdir),
		escapeshellarg($in),
		escapeshellarg('META-INF/license.lcpl')
	));
}


$dedrm_url = 'https://notabug.org/NewsGuyTor/DeDRM_tools-LCP/raw/d08098308c984347f54405959ec99a1a938d68bc/DeDRM_plugin/lcpdedrm.py';
$dedrm = file_get_contents($dedrm_url);

// DeDRM patch for use outside of Calibre
$patch = <<<EOF
20a21
> import sys
28c29
< from Crypto.Cipher import AES
---
> from Cryptodome.Cipher import AES
295c296
< def decryptLCPbook(inpath, passphrases, parent_object):
---
> def decryptLCPbook(inpath, outpath, passphrases):
445c446
<             outputname = parent_object.temporary_file(".pdf").name
---
>             outputname = outpath + ".pdf"
456c457
<             outputname = parent_object.temporary_file(".zip").name
---
>             outputname = outpath + ".zip"
470c471
<             outputname = parent_object.temporary_file(".epub").name
---
>             outputname = outpath + ".epub"
472c473
<             outputname = parent_object.temporary_file(".zip").name
---
>             outputname = outpath + ".zip"
519a521,527
> 
> def main(argv):
>     decryptLCPbook(argv[0], argv[1], [argv[2]])
> 
> if __name__ == "__main__":
>     main(sys.argv[1:])
> 

EOF;

$tmp_file = tempnam(sys_get_temp_dir(), 'dedrm');

// Save deDRM file in temporary file and patch it
file_put_contents($tmp_file, $dedrm);
file_put_contents($tmp_file . '.patch', $patch);

passthru(sprintf('patch %s < %s', escapeshellarg($tmp_file), escapeshellarg($tmp_file . '.patch')), $r);

if($r) {
	return;
}

@unlink($tmp_file . '.patch');

passthru(sprintf('python3 %s %s %s %s', escapeshellarg($tmp_file), escapeshellarg($in), escapeshellarg($out), escapeshellarg($password)));

@unlink($tmp_file);