| 1 |
<?php |
| 2 |
|
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namespace TablePress\PhpOffice\PhpSpreadsheet\Shared\Xlsx; |
| 4 |
|
| 5 |
use TablePress\PhpOffice\PhpSpreadsheet\Reader\Exception; |
| 6 |
use TablePress\PhpOffice\PhpSpreadsheet\Shared\File as SharedFile; |
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use TablePress\PhpOffice\PhpSpreadsheet\Shared\OLE; |
| 8 |
use SimpleXMLElement; |
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use Stringable; |
| 10 |
use Throwable; |
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|
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/** ECMA-376 Agile Encryption (AES-256/SHA-512 profile). */ |
| 13 |
final class AgileEncryption |
| 14 |
{ |
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public const MAX_SPIN_COUNT = 10000000; |
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|
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private const BLOCK_KEY_VERIFIER = "\xFE\xA7\xD2\x76\x3B\x4B\x9E\x79"; |
| 18 |
|
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private const BLOCK_KEY_VERIFIER_HASH = "\xD7\xAA\x0F\x6D\x30\x61\x34\x4E"; |
| 20 |
|
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private const BLOCK_KEY_ENCRYPTED_KEY = "\x14\x6E\x0B\xE7\xAB\xAC\xD0\xD6"; |
| 22 |
|
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private const BLOCK_KEY_HMAC_KEY = "\x5F\xB2\xAD\x01\x0C\xB9\xE1\xF6"; |
| 24 |
|
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private const BLOCK_KEY_HMAC_VALUE = "\xA0\x67\x7F\x02\xB2\x2C\x84\x33"; |
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|
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private const BLOCK_SIZE = 16; |
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|
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private const SEGMENT_SIZE = 4096; |
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|
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private const ENCRYPTION_NAMESPACE = 'http://schemas.microsoft.com/office/2006/encryption'; |
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|
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private const PASSWORD_NAMESPACE = 'http://schemas.microsoft.com/office/2006/keyEncryptor/password'; |
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|
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private const PASSWORD_KEY_ENCRYPTOR_URI = 'http://schemas.microsoft.com/office/2006/keyEncryptor/password'; |
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|
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private const CFB_SECTOR_SIZE = 512; |
| 38 |
|
| 39 |
private const CFB_MINI_SECTOR_SIZE = 64; |
| 40 |
|
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private const CFB_MINI_STREAM_CUTOFF = 4096; |
| 42 |
|
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private const CFB_FAT_ENTRIES_PER_SECTOR = self::CFB_SECTOR_SIZE >> 2; |
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|
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private const CFB_DIFAT_ENTRIES_IN_HEADER = 109; |
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|
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private const CFB_DIFAT_ENTRIES_PER_SECTOR = self::CFB_FAT_ENTRIES_PER_SECTOR - 1; |
| 48 |
|
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private const CFB_DIRECTORY_ENTRIES_PER_SECTOR = self::CFB_SECTOR_SIZE >> 7; |
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|
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private const CFB_MINI_SECTORS_PER_SECTOR = self::CFB_SECTOR_SIZE >> 6; |
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|
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private const DIRECTORY_ENCRYPTED_PACKAGE = 1; |
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|
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private const DIRECTORY_DATA_SPACES = 2; |
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|
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private const DIRECTORY_VERSION = 3; |
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|
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private const DIRECTORY_DATA_SPACE_MAP = 4; |
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|
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private const DIRECTORY_DATA_SPACE_INFO = 5; |
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|
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private const DIRECTORY_STRONG_ENCRYPTION_DATA_SPACE = 6; |
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|
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private const DIRECTORY_TRANSFORM_INFO = 7; |
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|
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private const DIRECTORY_STRONG_ENCRYPTION_TRANSFORM = 8; |
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|
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private const DIRECTORY_PRIMARY = 9; |
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|
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private const DIRECTORY_ENCRYPTION_INFO = 10; |
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|
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private const CFB_DIRECTORY_ENTRY_COUNT = self::DIRECTORY_ENCRYPTION_INFO + 1; |
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|
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private const STREAM_ENCRYPTED_PACKAGE = 'EncryptedPackage'; |
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|
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private const STORAGE_DATA_SPACES = "\x06DataSpaces"; |
| 78 |
|
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private const STREAM_VERSION = 'Version'; |
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|
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private const STREAM_DATA_SPACE_MAP = 'DataSpaceMap'; |
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|
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private const STORAGE_DATA_SPACE_INFO = 'DataSpaceInfo'; |
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|
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private const STREAM_STRONG_ENCRYPTION_DATA_SPACE = 'StrongEncryptionDataSpace'; |
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|
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private const STORAGE_TRANSFORM_INFO = 'TransformInfo'; |
| 88 |
|
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private const STORAGE_STRONG_ENCRYPTION_TRANSFORM = 'StrongEncryptionTransform'; |
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|
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private const STREAM_PRIMARY = "\x06Primary"; |
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|
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private const STREAM_ENCRYPTION_INFO = 'EncryptionInfo'; |
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|
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/** @var array<string, array{string, int}> */ |
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private const HASH_ALGORITHMS = [ |
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'SHA1' => ['sha1', 20], |
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'SHA256' => ['sha256', 32], |
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'SHA384' => ['sha384', 48], |
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'SHA512' => ['sha512', 64], |
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]; |
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|
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/** |
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* @return array{keyDataSalt: string, passwordSalt: string, encryptedVerifier: string, encryptedVerifierHash: string, encryptedKey: string, encryptedHmacKey: string, encryptedHmacValue: string, spinCount: int, keyBits: int, hashAlgorithm: string, hashSize: int} |
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*/ |
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public static function parse(string $encryptionInfo, int $maxSpinCount = self::MAX_SPIN_COUNT): array |
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{ |
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if (substr($encryptionInfo, 0, 8) !== "\x04\x00\x04\x00\x40\x00\x00\x00") { |
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throw new Exception('Unsupported XLSX encryption profile.'); |
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} |
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|
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$xml = @simplexml_load_string((string) substr($encryptionInfo, 8)); |
| 113 |
if (!$xml instanceof SimpleXMLElement) { |
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throw new Exception('Malformed XLSX encryption information.'); |
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} |
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$namespaces = $xml->getDocNamespaces(true) ?: []; |
| 117 |
if ($xml->getName() !== 'encryption' || !in_array(self::ENCRYPTION_NAMESPACE, $namespaces, true) || !in_array(self::PASSWORD_NAMESPACE, $namespaces, true)) { |
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throw new Exception('Unsupported XLSX encryption profile.'); |
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} |
| 120 |
$xml->registerXPathNamespace('e', self::ENCRYPTION_NAMESPACE); |
| 121 |
$xml->registerXPathNamespace('p', self::PASSWORD_NAMESPACE); |
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$keyDataNodes = $xml->xpath('/e:encryption/e:keyData') ?: []; |
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$integrityNodes = $xml->xpath('/e:encryption/e:dataIntegrity') ?: []; |
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$keyEncryptorNodes = $xml->xpath('/e:encryption/e:keyEncryptors/e:keyEncryptor') ?: []; |
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$encryptedKeyNodes = $xml->xpath('/e:encryption/e:keyEncryptors/e:keyEncryptor/p:encryptedKey') ?: []; |
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$keyData = $keyDataNodes[0] ?? null; |
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$integrity = $integrityNodes[0] ?? null; |
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$keyEncryptor = $keyEncryptorNodes[0] ?? null; |
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$encryptedKey = $encryptedKeyNodes[0] ?? null; |
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if (!$keyData instanceof SimpleXMLElement || !$integrity instanceof SimpleXMLElement || !$keyEncryptor instanceof SimpleXMLElement || !$encryptedKey instanceof SimpleXMLElement || count($keyDataNodes) !== 1 || count($integrityNodes) !== 1 || count($keyEncryptorNodes) !== 1 || count($encryptedKeyNodes) !== 1) { |
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throw new Exception('Unsupported XLSX encryption profile.'); |
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} |
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$keyBits = self::decimalAttribute($keyData, 'keyBits'); |
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$hashAlgorithm = (string) $keyData['hashAlgorithm']; |
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$hashSize = self::decimalAttribute($keyData, 'hashSize'); |
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$spinCount = self::decimalAttribute($encryptedKey, 'spinCount'); |
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$keyDataSaltSize = self::decimalAttribute($keyData, 'saltSize'); |
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$keyDataBlockSize = self::decimalAttribute($keyData, 'blockSize'); |
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$encryptedKeySaltSize = self::decimalAttribute($encryptedKey, 'saltSize'); |
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$encryptedKeyBlockSize = self::decimalAttribute($encryptedKey, 'blockSize'); |
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$encryptedKeyBits = self::decimalAttribute($encryptedKey, 'keyBits'); |
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$encryptedKeyHashSize = self::decimalAttribute($encryptedKey, 'hashSize'); |
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if ( |
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(string) $keyData['cipherAlgorithm'] !== 'AES' || (string) $keyData['cipherChaining'] !== 'ChainingModeCBC' |
| 145 |
|| !self::isSupportedProfile($keyBits, $hashAlgorithm, $hashSize) || $keyDataSaltSize !== 16 || $keyDataBlockSize !== 16 |
| 146 |
|| (string) $encryptedKey['cipherAlgorithm'] !== 'AES' |
| 147 |
|| (string) $encryptedKey['cipherChaining'] !== 'ChainingModeCBC' |
| 148 |
|| (string) $encryptedKey['hashAlgorithm'] !== $hashAlgorithm || $encryptedKeySaltSize !== 16 || $encryptedKeyBlockSize !== 16 || $encryptedKeyBits !== $keyBits |
| 149 |
|| $encryptedKeyHashSize !== $hashSize || $spinCount > min($maxSpinCount, self::MAX_SPIN_COUNT) |
| 150 |
|| (string) $keyEncryptor['uri'] !== self::PASSWORD_KEY_ENCRYPTOR_URI |
| 151 |
) { |
| 152 |
throw new Exception('Unsupported XLSX encryption profile.'); |
| 153 |
} |
| 154 |
|
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$result = [ |
| 156 |
'keyDataSalt' => self::decode($keyData['saltValue']), |
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'passwordSalt' => self::decode($encryptedKey['saltValue']), |
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'encryptedVerifier' => self::decode($encryptedKey['encryptedVerifierHashInput']), |
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'encryptedVerifierHash' => self::decode($encryptedKey['encryptedVerifierHashValue']), |
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'encryptedKey' => self::decode($encryptedKey['encryptedKeyValue']), |
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'encryptedHmacKey' => self::decode($integrity['encryptedHmacKey']), |
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'encryptedHmacValue' => self::decode($integrity['encryptedHmacValue']), |
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'spinCount' => $spinCount, |
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'keyBits' => $keyBits, |
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'hashAlgorithm' => $hashAlgorithm, |
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'hashSize' => $hashSize, |
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]; |
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if ( |
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strlen($result['keyDataSalt']) !== 16 || strlen($result['passwordSalt']) !== 16 |
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|| strlen($result['encryptedVerifier']) !== 16 || strlen($result['encryptedVerifierHash']) !== self::paddedLength($hashSize) |
| 171 |
|| strlen($result['encryptedKey']) !== self::paddedLength(intdiv($keyBits, 8)) || strlen($result['encryptedHmacKey']) !== self::paddedLength($hashSize) |
| 172 |
|| strlen($result['encryptedHmacValue']) !== self::paddedLength($hashSize) |
| 173 |
) { |
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throw new Exception('Malformed XLSX encryption information.'); |
| 175 |
} |
| 176 |
|
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return $result; |
| 178 |
} |
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|
| 180 |
/** @param array{keyDataSalt: string, passwordSalt: string, encryptedVerifier: string, encryptedVerifierHash: string, encryptedKey: string, encryptedHmacKey: string, encryptedHmacValue: string, spinCount: int, keyBits: int, hashAlgorithm: string, hashSize: int} $info */ |
| 181 |
public static function decrypt(array $info, string $encryptedPackage, string $password): string |
| 182 |
{ |
| 183 |
if ($password === '') { |
| 184 |
throw new Exception('XLSX encryption password required.'); |
| 185 |
} |
| 186 |
if (strlen($encryptedPackage) < 8) { |
| 187 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 188 |
} |
| 189 |
$hash = self::passwordHash($password, $info['passwordSalt'], $info['spinCount'], $info['hashAlgorithm']); |
| 190 |
$verifierKey = self::deriveKey($hash, self::BLOCK_KEY_VERIFIER, $info['hashAlgorithm'], $info['keyBits']); |
| 191 |
$verifierHashKey = self::deriveKey($hash, self::BLOCK_KEY_VERIFIER_HASH, $info['hashAlgorithm'], $info['keyBits']); |
| 192 |
$verifier = self::aesDecrypt($info['encryptedVerifier'], $verifierKey, $info['passwordSalt'], $info['keyBits']); |
| 193 |
$expectedHash = self::aesDecrypt($info['encryptedVerifierHash'], $verifierHashKey, $info['passwordSalt'], $info['keyBits']); |
| 194 |
if (!hash_equals(self::hash($info['hashAlgorithm'], $verifier), (string) substr($expectedHash, 0, $info['hashSize']))) { |
| 195 |
throw new Exception('XLSX encryption password is incorrect.'); |
| 196 |
} |
| 197 |
$secretKey = self::aesDecrypt($info['encryptedKey'], self::deriveKey($hash, self::BLOCK_KEY_ENCRYPTED_KEY, $info['hashAlgorithm'], $info['keyBits']), $info['passwordSalt'], $info['keyBits']); |
| 198 |
$secretKey = (string) substr($secretKey, 0, intdiv($info['keyBits'], 8)); |
| 199 |
if (strlen($secretKey) !== intdiv($info['keyBits'], 8)) { |
| 200 |
throw new Exception('Malformed XLSX encryption information.'); |
| 201 |
} |
| 202 |
self::verifyIntegrity($info, $secretKey, $encryptedPackage); |
| 203 |
$size = self::unpackSize(substr($encryptedPackage, 0, 8)); |
| 204 |
$offset = 8; |
| 205 |
$plain = ''; |
| 206 |
for ($block = 0; $size > 0; ++$block) { |
| 207 |
$length = min(self::SEGMENT_SIZE, $size); |
| 208 |
$cipherLength = (int) (ceil($length / self::BLOCK_SIZE) * self::BLOCK_SIZE); |
| 209 |
$cipher = (string) substr($encryptedPackage, $offset, $cipherLength); |
| 210 |
if (strlen($cipher) !== $cipherLength) { |
| 211 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 212 |
} |
| 213 |
$iv = self::iv($info['keyDataSalt'], pack('V', $block), $info['hashAlgorithm']); |
| 214 |
$plain .= substr(self::aesDecrypt($cipher, $secretKey, $iv, $info['keyBits']), 0, $length); |
| 215 |
$offset += $cipherLength; |
| 216 |
$size -= $length; |
| 217 |
} |
| 218 |
if ($offset !== strlen($encryptedPackage)) { |
| 219 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 220 |
} |
| 221 |
|
| 222 |
return $plain; |
| 223 |
} |
| 224 |
|
| 225 |
/** @param array{keyDataSalt: string, passwordSalt: string, encryptedVerifier: string, encryptedVerifierHash: string, encryptedKey: string, encryptedHmacKey: string, encryptedHmacValue: string, spinCount: int, keyBits: int, hashAlgorithm: string, hashSize: int} $info */ |
| 226 |
public static function decryptFile(array $info, string $inputFilename, string $outputFilename, string $password): void |
| 227 |
{ |
| 228 |
if ($password === '') { |
| 229 |
throw new Exception('XLSX encryption password required.'); |
| 230 |
} |
| 231 |
$input = @fopen($inputFilename, 'rb'); |
| 232 |
if ($input === false) { |
| 233 |
throw new Exception('Could not open XLSX package for decryption.'); |
| 234 |
} |
| 235 |
|
| 236 |
try { |
| 237 |
$hash = self::passwordHash($password, $info['passwordSalt'], $info['spinCount'], $info['hashAlgorithm']); |
| 238 |
$verifier = self::aesDecrypt($info['encryptedVerifier'], self::deriveKey($hash, self::BLOCK_KEY_VERIFIER, $info['hashAlgorithm'], $info['keyBits']), $info['passwordSalt'], $info['keyBits']); |
| 239 |
$expected = self::aesDecrypt($info['encryptedVerifierHash'], self::deriveKey($hash, self::BLOCK_KEY_VERIFIER_HASH, $info['hashAlgorithm'], $info['keyBits']), $info['passwordSalt'], $info['keyBits']); |
| 240 |
if (!hash_equals(self::hash($info['hashAlgorithm'], $verifier), (string) substr($expected, 0, $info['hashSize']))) { |
| 241 |
throw new Exception('XLSX encryption password is incorrect.'); |
| 242 |
} |
| 243 |
$secretKey = (string) substr(self::aesDecrypt($info['encryptedKey'], self::deriveKey($hash, self::BLOCK_KEY_ENCRYPTED_KEY, $info['hashAlgorithm'], $info['keyBits']), $info['passwordSalt'], $info['keyBits']), 0, intdiv($info['keyBits'], 8)); |
| 244 |
if (strlen($secretKey) !== intdiv($info['keyBits'], 8)) { |
| 245 |
throw new Exception('Malformed XLSX encryption information.'); |
| 246 |
} |
| 247 |
self::verifyIntegrityFile($info, $secretKey, $input); |
| 248 |
$output = @fopen($outputFilename, 'wb'); |
| 249 |
if ($output === false) { |
| 250 |
throw new Exception('Could not open XLSX package for decryption.'); |
| 251 |
} |
| 252 |
rewind($input); |
| 253 |
|
| 254 |
try { |
| 255 |
$size = self::unpackSize(self::read($input, 8)); |
| 256 |
for ($block = 0; $size > 0; ++$block) { |
| 257 |
$length = min(self::SEGMENT_SIZE, $size); |
| 258 |
$cipher = self::read($input, self::paddedLength($length)); |
| 259 |
$iv = self::iv($info['keyDataSalt'], pack('V', $block), $info['hashAlgorithm']); |
| 260 |
self::write($output, (string) substr(self::aesDecrypt($cipher, $secretKey, $iv, $info['keyBits']), 0, $length)); |
| 261 |
$size -= $length; |
| 262 |
} |
| 263 |
if (fread($input, 1) !== '') { |
| 264 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 265 |
} |
| 266 |
} finally { |
| 267 |
fclose($output); |
| 268 |
} |
| 269 |
} finally { |
| 270 |
fclose($input); |
| 271 |
} |
| 272 |
} |
| 273 |
|
| 274 |
/** |
| 275 |
* Create the EncryptionInfo and EncryptedPackage streams for an Agile-encrypted XLSX. |
| 276 |
* |
| 277 |
* @return array{encryptionInfo: string, encryptedPackage: string} |
| 278 |
*/ |
| 279 |
public static function encrypt(string $plainPackage, string $password, int $keyBits = 256, string $hashAlgorithm = 'SHA512', int $spinCount = 100000): array |
| 280 |
{ |
| 281 |
if ($password === '') { |
| 282 |
throw new Exception('XLSX encryption password required.'); |
| 283 |
} |
| 284 |
if (!self::isSupportedProfile($keyBits, $hashAlgorithm, self::HASH_ALGORITHMS[$hashAlgorithm][1] ?? 0) || $spinCount < 0 || $spinCount > self::MAX_SPIN_COUNT) { |
| 285 |
throw new Exception('Unsupported XLSX encryption profile.'); |
| 286 |
} |
| 287 |
|
| 288 |
$passwordSalt = random_bytes(self::BLOCK_SIZE); |
| 289 |
$keyDataSalt = random_bytes(self::BLOCK_SIZE); |
| 290 |
$hashSize = self::hashSize($hashAlgorithm); |
| 291 |
$passwordHash = self::passwordHash($password, $passwordSalt, $spinCount, $hashAlgorithm); |
| 292 |
$verifier = random_bytes(self::BLOCK_SIZE); |
| 293 |
$secretKey = random_bytes(self::keyLength($keyBits)); |
| 294 |
$encryptedVerifier = self::aesEncrypt($verifier, self::deriveKey($passwordHash, self::BLOCK_KEY_VERIFIER, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 295 |
$encryptedVerifierHash = self::aesEncrypt(str_pad(self::hash($hashAlgorithm, $verifier), self::paddedLength($hashSize), "\x00"), self::deriveKey($passwordHash, self::BLOCK_KEY_VERIFIER_HASH, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 296 |
$encryptedKey = self::aesEncrypt(str_pad($secretKey, self::paddedLength(strlen($secretKey)), "\x00"), self::deriveKey($passwordHash, self::BLOCK_KEY_ENCRYPTED_KEY, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 297 |
|
| 298 |
$encryptedPackage = self::packSize(strlen($plainPackage)); |
| 299 |
for ($block = 0, $offset = 0; $offset < strlen($plainPackage); ++$block, $offset += self::SEGMENT_SIZE) { |
| 300 |
$segment = (string) substr($plainPackage, $offset, self::SEGMENT_SIZE); |
| 301 |
$iv = self::iv($keyDataSalt, pack('V', $block), $hashAlgorithm); |
| 302 |
$encryptedPackage .= self::aesEncrypt(str_pad($segment, self::paddedLength(strlen($segment)), "\x00"), $secretKey, $iv, $keyBits); |
| 303 |
} |
| 304 |
|
| 305 |
$hmacKey = random_bytes(self::hashSize($hashAlgorithm)); |
| 306 |
$hmacKeyIv = self::iv($keyDataSalt, self::BLOCK_KEY_HMAC_KEY, $hashAlgorithm); |
| 307 |
$hmacValueIv = self::iv($keyDataSalt, self::BLOCK_KEY_HMAC_VALUE, $hashAlgorithm); |
| 308 |
$encryptedHmacKey = self::aesEncrypt(str_pad($hmacKey, self::paddedLength($hashSize), "\x00"), $secretKey, $hmacKeyIv, $keyBits); |
| 309 |
$encryptedHmacValue = self::aesEncrypt(str_pad(hash_hmac(self::HASH_ALGORITHMS[$hashAlgorithm][0], $encryptedPackage, $hmacKey, true), self::paddedLength($hashSize), "\x00"), $secretKey, $hmacValueIv, $keyBits); |
| 310 |
|
| 311 |
$encryptionInfo = "\x04\x00\x04\x00\x40\x00\x00\x00" . self::encryptionInfoXml( |
| 312 |
$keyDataSalt, |
| 313 |
$passwordSalt, |
| 314 |
$encryptedVerifier, |
| 315 |
$encryptedVerifierHash, |
| 316 |
$encryptedKey, |
| 317 |
$encryptedHmacKey, |
| 318 |
$encryptedHmacValue, |
| 319 |
$keyBits, |
| 320 |
$hashAlgorithm, |
| 321 |
$hashSize, |
| 322 |
$spinCount |
| 323 |
); |
| 324 |
|
| 325 |
return ['encryptionInfo' => $encryptionInfo, 'encryptedPackage' => $encryptedPackage]; |
| 326 |
} |
| 327 |
|
| 328 |
/** |
| 329 |
* Encrypt a ZIP package without loading either package into memory. |
| 330 |
* |
| 331 |
* @return array{encryptionInfo: string, encryptedPackageFilename: string} |
| 332 |
*/ |
| 333 |
public static function encryptFile(string $plainPackageFilename, string $password, int $keyBits = 256, string $hashAlgorithm = 'SHA512', int $spinCount = 100000): array |
| 334 |
{ |
| 335 |
if ($password === '') { |
| 336 |
throw new Exception('XLSX encryption password required.'); |
| 337 |
} |
| 338 |
if (!self::isSupportedProfile($keyBits, $hashAlgorithm, self::HASH_ALGORITHMS[$hashAlgorithm][1] ?? 0) || $spinCount < 0 || $spinCount > self::MAX_SPIN_COUNT) { |
| 339 |
throw new Exception('Unsupported XLSX encryption profile.'); |
| 340 |
} |
| 341 |
$size = @filesize($plainPackageFilename); |
| 342 |
if ($size === false) { |
| 343 |
throw new Exception('Could not determine XLSX package size.'); |
| 344 |
} |
| 345 |
$input = fopen($plainPackageFilename, 'rb'); |
| 346 |
if ($input === false) { |
| 347 |
throw new Exception('Could not open XLSX package for encryption.'); |
| 348 |
} |
| 349 |
$encryptedPackageFilename = SharedFile::temporaryFilename(); |
| 350 |
$output = fopen($encryptedPackageFilename, 'wb'); |
| 351 |
if ($output === false) { |
| 352 |
fclose($input); |
| 353 |
@unlink($encryptedPackageFilename); |
| 354 |
|
| 355 |
throw new Exception('Could not create encrypted XLSX package.'); |
| 356 |
} |
| 357 |
|
| 358 |
try { |
| 359 |
$passwordSalt = random_bytes(self::BLOCK_SIZE); |
| 360 |
$keyDataSalt = random_bytes(self::BLOCK_SIZE); |
| 361 |
$hashSize = self::hashSize($hashAlgorithm); |
| 362 |
$passwordHash = self::passwordHash($password, $passwordSalt, $spinCount, $hashAlgorithm); |
| 363 |
$verifier = random_bytes(self::BLOCK_SIZE); |
| 364 |
$secretKey = random_bytes(self::keyLength($keyBits)); |
| 365 |
$encryptedVerifier = self::aesEncrypt($verifier, self::deriveKey($passwordHash, self::BLOCK_KEY_VERIFIER, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 366 |
$encryptedVerifierHash = self::aesEncrypt(str_pad(self::hash($hashAlgorithm, $verifier), self::paddedLength($hashSize), "\x00"), self::deriveKey($passwordHash, self::BLOCK_KEY_VERIFIER_HASH, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 367 |
$encryptedKey = self::aesEncrypt(str_pad($secretKey, self::paddedLength(strlen($secretKey)), "\x00"), self::deriveKey($passwordHash, self::BLOCK_KEY_ENCRYPTED_KEY, $hashAlgorithm, $keyBits), $passwordSalt, $keyBits); |
| 368 |
$hmacKey = random_bytes(self::hashSize($hashAlgorithm)); |
| 369 |
$hmac = hash_init(self::HASH_ALGORITHMS[$hashAlgorithm][0], HASH_HMAC, $hmacKey); |
| 370 |
$header = self::packSize($size); |
| 371 |
self::write($output, $header); |
| 372 |
hash_update($hmac, $header); |
| 373 |
$remaining = $size; |
| 374 |
for ($block = 0; $remaining > 0; ++$block) { |
| 375 |
$length = min(self::SEGMENT_SIZE, $remaining); |
| 376 |
$segment = fread($input, $length); |
| 377 |
if ($segment === false || strlen($segment) !== $length) { |
| 378 |
throw new Exception('Could not read XLSX package for encryption.'); |
| 379 |
} |
| 380 |
$iv = self::iv($keyDataSalt, pack('V', $block), $hashAlgorithm); |
| 381 |
$cipher = self::aesEncrypt(str_pad($segment, self::paddedLength(strlen($segment)), "\x00"), $secretKey, $iv, $keyBits); |
| 382 |
self::write($output, $cipher); |
| 383 |
hash_update($hmac, $cipher); |
| 384 |
$remaining -= $length; |
| 385 |
} |
| 386 |
$extra = fread($input, 1); |
| 387 |
if ($extra === false || $extra !== '') { |
| 388 |
throw new Exception('XLSX package changed while being encrypted.'); |
| 389 |
} |
| 390 |
$hmacKeyIv = self::iv($keyDataSalt, self::BLOCK_KEY_HMAC_KEY, $hashAlgorithm); |
| 391 |
$hmacValueIv = self::iv($keyDataSalt, self::BLOCK_KEY_HMAC_VALUE, $hashAlgorithm); |
| 392 |
$encryptedHmacKey = self::aesEncrypt(str_pad($hmacKey, self::paddedLength($hashSize), "\x00"), $secretKey, $hmacKeyIv, $keyBits); |
| 393 |
$encryptedHmacValue = self::aesEncrypt(str_pad(hash_final($hmac, true), self::paddedLength($hashSize), "\x00"), $secretKey, $hmacValueIv, $keyBits); |
| 394 |
$encryptionInfo = "\x04\x00\x04\x00\x40\x00\x00\x00" . self::encryptionInfoXml($keyDataSalt, $passwordSalt, $encryptedVerifier, $encryptedVerifierHash, $encryptedKey, $encryptedHmacKey, $encryptedHmacValue, $keyBits, $hashAlgorithm, $hashSize, $spinCount); |
| 395 |
} catch (Throwable $e) { |
| 396 |
@unlink($encryptedPackageFilename); |
| 397 |
|
| 398 |
throw $e; |
| 399 |
} finally { |
| 400 |
fclose($input); |
| 401 |
fclose($output); |
| 402 |
} |
| 403 |
|
| 404 |
return ['encryptionInfo' => $encryptionInfo, 'encryptedPackageFilename' => $encryptedPackageFilename]; |
| 405 |
} |
| 406 |
|
| 407 |
/** |
| 408 |
* Write an Office encrypted package CFB container using a file-backed EncryptedPackage stream. |
| 409 |
* |
| 410 |
* @param resource $fileHandle |
| 411 |
*/ |
| 412 |
public static function writeContainerFromFile($fileHandle, string $encryptionInfo, string $encryptedPackageFilename): void |
| 413 |
{ |
| 414 |
$containerFilename = SharedFile::temporaryFilename(); |
| 415 |
$container = fopen($containerFilename, 'w+b'); |
| 416 |
if ($container === false) { |
| 417 |
@unlink($containerFilename); |
| 418 |
|
| 419 |
throw new Exception('Could not create encrypted XLSX container.'); |
| 420 |
} |
| 421 |
|
| 422 |
try { |
| 423 |
self::writeEcma376Container($container, $encryptionInfo, $encryptedPackageFilename); |
| 424 |
rewind($container); |
| 425 |
while (!feof($container)) { |
| 426 |
$data = fread($container, 8192); |
| 427 |
if ($data === false) { |
| 428 |
throw new Exception('Could not read encrypted XLSX container.'); |
| 429 |
} |
| 430 |
if ($data !== '' && fwrite($fileHandle, $data) !== strlen($data)) { |
| 431 |
throw new Exception('Could not write encrypted XLSX container.'); |
| 432 |
} |
| 433 |
} |
| 434 |
} finally { |
| 435 |
fclose($container); |
| 436 |
@unlink($containerFilename); |
| 437 |
} |
| 438 |
} |
| 439 |
|
| 440 |
/** |
| 441 |
* Serialize the ECMA-376 encrypted-package CFB layout. The directory tree |
| 442 |
* is prescribed by the Data Spaces structure; sector allocation is dynamic |
| 443 |
* so normal workbook size is not artificially constrained. |
| 444 |
* |
| 445 |
* @param resource $fileHandle |
| 446 |
*/ |
| 447 |
private static function writeEcma376Container($fileHandle, string $encryptionInfo, string $encryptedPackageFilename): void |
| 448 |
{ |
| 449 |
$packageSize = filesize($encryptedPackageFilename); |
| 450 |
if ($packageSize === false || $packageSize < self::CFB_MINI_STREAM_CUTOFF || $packageSize > 0xFFFFFFFF) { |
| 451 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 452 |
} |
| 453 |
$smallStreams = [ |
| 454 |
self::DIRECTORY_VERSION => [self::STREAM_VERSION, self::dataSpacesVersion()], |
| 455 |
self::DIRECTORY_DATA_SPACE_MAP => [self::STREAM_DATA_SPACE_MAP, self::dataSpaceMap()], |
| 456 |
self::DIRECTORY_STRONG_ENCRYPTION_DATA_SPACE => [self::STREAM_STRONG_ENCRYPTION_DATA_SPACE, self::strongEncryptionDataSpace()], |
| 457 |
self::DIRECTORY_PRIMARY => [self::STREAM_PRIMARY, self::primaryTransform()], |
| 458 |
self::DIRECTORY_ENCRYPTION_INFO => [self::STREAM_ENCRYPTION_INFO, $encryptionInfo], |
| 459 |
]; |
| 460 |
$miniStarts = array_fill_keys(array_keys($smallStreams), 0); |
| 461 |
$miniFat = []; |
| 462 |
$miniCount = 0; |
| 463 |
foreach ($smallStreams as $id => [, $content]) { |
| 464 |
if (strlen($content) >= self::CFB_MINI_STREAM_CUTOFF) { |
| 465 |
throw new Exception('Malformed XLSX encryption information.'); |
| 466 |
} |
| 467 |
$count = (int) ceil(strlen($content) / self::CFB_MINI_SECTOR_SIZE); |
| 468 |
$miniStarts[$id] = $miniCount; |
| 469 |
for ($i = 0; $i < $count - 1; ++$i) { |
| 470 |
$miniFat[$miniCount + $i] = $miniCount + $i + 1; |
| 471 |
} |
| 472 |
$miniFat[$miniCount + $count - 1] = 0xFFFFFFFE; |
| 473 |
$miniCount += $count; |
| 474 |
} |
| 475 |
$miniFatSectors = (int) ceil($miniCount / self::CFB_FAT_ENTRIES_PER_SECTOR); |
| 476 |
$miniFat = array_pad($miniFat, $miniFatSectors * self::CFB_FAT_ENTRIES_PER_SECTOR, 0xFFFFFFFF); |
| 477 |
$miniDataSectors = (int) ceil($miniCount / self::CFB_MINI_SECTORS_PER_SECTOR); |
| 478 |
$directorySectors = (int) ceil(self::CFB_DIRECTORY_ENTRY_COUNT / self::CFB_DIRECTORY_ENTRIES_PER_SECTOR); |
| 479 |
$packageSectors = (int) ceil($packageSize / self::CFB_SECTOR_SIZE); |
| 480 |
$contentSectors = $miniFatSectors + $directorySectors + $miniDataSectors + $packageSectors; |
| 481 |
$fatSectors = 1; |
| 482 |
$difatSectors = 0; |
| 483 |
do { |
| 484 |
$requiredFatSectors = (int) ceil(($contentSectors + $fatSectors + $difatSectors) / self::CFB_FAT_ENTRIES_PER_SECTOR); |
| 485 |
$requiredDifatSectors = $requiredFatSectors <= self::CFB_DIFAT_ENTRIES_IN_HEADER ? 0 : (int) ceil(($requiredFatSectors - self::CFB_DIFAT_ENTRIES_IN_HEADER) / self::CFB_DIFAT_ENTRIES_PER_SECTOR); |
| 486 |
$changed = $requiredFatSectors !== $fatSectors || $requiredDifatSectors !== $difatSectors; |
| 487 |
$fatSectors = $requiredFatSectors; |
| 488 |
$difatSectors = $requiredDifatSectors; |
| 489 |
} while ($changed); |
| 490 |
$miniFatSector = $fatSectors; |
| 491 |
$directorySector = $miniFatSector + $miniFatSectors; |
| 492 |
$miniDataSector = $directorySector + $directorySectors; |
| 493 |
$packageSector = $miniDataSector + $miniDataSectors; |
| 494 |
$difatSector = $packageSector + $packageSectors; |
| 495 |
|
| 496 |
self::write($fileHandle, self::cfbHeader($fatSectors, $directorySector, $miniFatSector, $miniFatSectors, $difatSector, $difatSectors)); |
| 497 |
$fat = array_fill(0, $fatSectors * self::CFB_FAT_ENTRIES_PER_SECTOR, 0xFFFFFFFF); |
| 498 |
for ($sector = 0; $sector < $fatSectors; ++$sector) { |
| 499 |
$fat[$sector] = 0xFFFFFFFD; |
| 500 |
} |
| 501 |
self::chainFat($fat, $miniFatSector, $miniFatSectors); |
| 502 |
self::chainFat($fat, $directorySector, $directorySectors); |
| 503 |
self::chainFat($fat, $miniDataSector, $miniDataSectors); |
| 504 |
self::chainFat($fat, $packageSector, $packageSectors); |
| 505 |
for ($sector = 0; $sector < $difatSectors; ++$sector) { |
| 506 |
$fat[$difatSector + $sector] = 0xFFFFFFFC; |
| 507 |
} |
| 508 |
self::write($fileHandle, self::packSectors($fat)); |
| 509 |
self::write($fileHandle, self::packSectors($miniFat)); |
| 510 |
|
| 511 |
$entries = [ |
| 512 |
// CFB sibling trees sort by name length, then case-folded UTF-16 code points. |
| 513 |
self::directoryEntry('Root Entry', 5, 1, 0xFFFFFFFF, 0xFFFFFFFF, self::DIRECTORY_ENCRYPTION_INFO, $miniDataSector, $miniCount * self::CFB_MINI_SECTOR_SIZE), |
| 514 |
self::directoryEntry(self::STREAM_ENCRYPTED_PACKAGE, 2, 0, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, $packageSector, $packageSize), |
| 515 |
self::directoryEntry(self::STORAGE_DATA_SPACES, 1, 0, 0xFFFFFFFF, 0xFFFFFFFF, self::DIRECTORY_DATA_SPACE_MAP, 0, 0), |
| 516 |
self::directoryEntry(self::STREAM_VERSION, 2, 0, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, $miniStarts[self::DIRECTORY_VERSION], strlen($smallStreams[self::DIRECTORY_VERSION][1])), |
| 517 |
self::directoryEntry(self::STREAM_DATA_SPACE_MAP, 2, 1, self::DIRECTORY_VERSION, self::DIRECTORY_DATA_SPACE_INFO, 0xFFFFFFFF, $miniStarts[self::DIRECTORY_DATA_SPACE_MAP], strlen($smallStreams[self::DIRECTORY_DATA_SPACE_MAP][1])), |
| 518 |
self::directoryEntry(self::STORAGE_DATA_SPACE_INFO, 1, 0, 0xFFFFFFFF, 0xFFFFFFFF, self::DIRECTORY_TRANSFORM_INFO, 0, 0), |
| 519 |
self::directoryEntry(self::STREAM_STRONG_ENCRYPTION_DATA_SPACE, 2, 0, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, $miniStarts[self::DIRECTORY_STRONG_ENCRYPTION_DATA_SPACE], strlen($smallStreams[self::DIRECTORY_STRONG_ENCRYPTION_DATA_SPACE][1])), |
| 520 |
self::directoryEntry(self::STORAGE_TRANSFORM_INFO, 1, 1, self::DIRECTORY_STRONG_ENCRYPTION_DATA_SPACE, 0xFFFFFFFF, self::DIRECTORY_STRONG_ENCRYPTION_TRANSFORM, 0, 0), |
| 521 |
self::directoryEntry(self::STORAGE_STRONG_ENCRYPTION_TRANSFORM, 1, 1, 0xFFFFFFFF, 0xFFFFFFFF, self::DIRECTORY_PRIMARY, 0, 0), |
| 522 |
self::directoryEntry(self::STREAM_PRIMARY, 2, 1, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, $miniStarts[self::DIRECTORY_PRIMARY], strlen($smallStreams[self::DIRECTORY_PRIMARY][1])), |
| 523 |
self::directoryEntry(self::STREAM_ENCRYPTION_INFO, 2, 1, self::DIRECTORY_DATA_SPACES, self::DIRECTORY_ENCRYPTED_PACKAGE, 0xFFFFFFFF, $miniStarts[self::DIRECTORY_ENCRYPTION_INFO], strlen($smallStreams[self::DIRECTORY_ENCRYPTION_INFO][1])), |
| 524 |
]; |
| 525 |
self::write($fileHandle, str_pad(implode('', $entries), $directorySectors * self::CFB_SECTOR_SIZE, "\x00")); |
| 526 |
$miniData = str_repeat("\x00", $miniDataSectors * self::CFB_SECTOR_SIZE); |
| 527 |
foreach ($smallStreams as $id => [, $content]) { |
| 528 |
$miniData = substr_replace($miniData, $content, $miniStarts[$id] * self::CFB_MINI_SECTOR_SIZE, strlen($content)); |
| 529 |
} |
| 530 |
self::write($fileHandle, $miniData); |
| 531 |
$package = fopen($encryptedPackageFilename, 'rb'); |
| 532 |
if ($package === false) { |
| 533 |
throw new Exception('Could not open encrypted XLSX package.'); |
| 534 |
} |
| 535 |
|
| 536 |
try { |
| 537 |
while (!feof($package)) { |
| 538 |
$data = fread($package, 8192); |
| 539 |
if ($data === false) { |
| 540 |
throw new Exception('Could not read encrypted XLSX package.'); |
| 541 |
} |
| 542 |
if ($data !== '') { |
| 543 |
self::write($fileHandle, $data); |
| 544 |
} |
| 545 |
} |
| 546 |
} finally { |
| 547 |
fclose($package); |
| 548 |
} |
| 549 |
$padding = $packageSectors * self::CFB_SECTOR_SIZE - $packageSize; |
| 550 |
if ($padding > 0) { |
| 551 |
self::write($fileHandle, str_repeat("\x00", $padding)); |
| 552 |
} |
| 553 |
for ($sector = 0; $sector < $difatSectors; ++$sector) { |
| 554 |
$firstFatSector = self::CFB_DIFAT_ENTRIES_IN_HEADER + $sector * self::CFB_DIFAT_ENTRIES_PER_SECTOR; |
| 555 |
$fatReferences = []; |
| 556 |
for ($i = 0; $i < self::CFB_DIFAT_ENTRIES_PER_SECTOR; ++$i) { |
| 557 |
$fatReferences[] = $firstFatSector + $i < $fatSectors ? $firstFatSector + $i : 0xFFFFFFFF; |
| 558 |
} |
| 559 |
$fatReferences[] = $sector + 1 < $difatSectors ? $difatSector + $sector + 1 : 0xFFFFFFFE; |
| 560 |
self::write($fileHandle, self::packSectors($fatReferences)); |
| 561 |
} |
| 562 |
} |
| 563 |
|
| 564 |
/** @param int[] $fat */ |
| 565 |
private static function chainFat(array &$fat, int $start, int $count): void |
| 566 |
{ |
| 567 |
for ($i = 0; $i < $count - 1; ++$i) { |
| 568 |
$fat[$start + $i] = $start + $i + 1; |
| 569 |
} |
| 570 |
$fat[$start + $count - 1] = 0xFFFFFFFE; |
| 571 |
} |
| 572 |
|
| 573 |
/** @param int[] $sectors */ |
| 574 |
private static function packSectors(array $sectors): string |
| 575 |
{ |
| 576 |
return pack('V*', ...$sectors); |
| 577 |
} |
| 578 |
|
| 579 |
private static function cfbHeader(int $fatSectors, int $directorySector, int $miniFatSector, int $miniFatSectors, int $difatSector, int $difatSectors): string |
| 580 |
{ |
| 581 |
$headerDifat = []; |
| 582 |
for ($sector = 0; $sector < self::CFB_DIFAT_ENTRIES_IN_HEADER; ++$sector) { |
| 583 |
$headerDifat[] = $sector < $fatSectors ? $sector : 0xFFFFFFFF; |
| 584 |
} |
| 585 |
|
| 586 |
return "\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1" . str_repeat("\x00", 16) |
| 587 |
. pack('v8', 0x3E, 3, 0xFFFE, 9, 6, 0, 0, 0) |
| 588 |
. pack('V8', 0, $fatSectors, $directorySector, 0, self::CFB_MINI_STREAM_CUTOFF, $miniFatSector, $miniFatSectors, $difatSectors === 0 ? 0xFFFFFFFE : $difatSector) |
| 589 |
. pack('V', $difatSectors) . self::packSectors($headerDifat); |
| 590 |
} |
| 591 |
|
| 592 |
private static function directoryEntry(string $name, int $type, int $color, int $left, int $right, int $child, int $start, int $size): string |
| 593 |
{ |
| 594 |
$name = OLE::ascToUcs($name); |
| 595 |
|
| 596 |
return str_pad($name, 64, "\x00") . pack('vCCVVV', strlen($name) + 2, $type, $color, $left, $right, $child) |
| 597 |
. str_repeat("\x00", 16) . pack('V', 0) . str_repeat("\x00", 16) |
| 598 |
. pack('V2', $start, $size % 4294967296) . pack('V', intdiv($size, 4294967296)); |
| 599 |
} |
| 600 |
|
| 601 |
/** |
| 602 |
* @param mixed $value |
| 603 |
*/ |
| 604 |
private static function decode($value): string |
| 605 |
{ |
| 606 |
if (!is_string($value) && !(is_object($value) && method_exists($value, '__toString'))) { |
| 607 |
throw new Exception('Malformed XLSX encryption information.'); |
| 608 |
} |
| 609 |
$result = base64_decode((string) $value, true); |
| 610 |
if ($result === false) { |
| 611 |
throw new Exception('Malformed XLSX encryption information.'); |
| 612 |
} |
| 613 |
|
| 614 |
return $result; |
| 615 |
} |
| 616 |
|
| 617 |
private static function decimalAttribute(SimpleXMLElement $element, string $name): int |
| 618 |
{ |
| 619 |
$value = (string) $element[$name]; |
| 620 |
$maximum = (string) PHP_INT_MAX; |
| 621 |
if ($value === '' || !ctype_digit($value) || strlen($value) > strlen($maximum) || (strlen($value) === strlen($maximum) && $value > $maximum)) { |
| 622 |
throw new Exception('Malformed XLSX encryption information.'); |
| 623 |
} |
| 624 |
|
| 625 |
return (int) $value; |
| 626 |
} |
| 627 |
|
| 628 |
private static function passwordHash(string $password, string $salt, int $spinCount, string $algorithm = 'SHA512'): string |
| 629 |
{ |
| 630 |
$hash = self::hash($algorithm, $salt . mb_convert_encoding($password, 'UTF-16LE', 'UTF-8')); |
| 631 |
for ($i = 0; $i < $spinCount; ++$i) { |
| 632 |
$hash = self::hash($algorithm, pack('V', $i) . $hash); |
| 633 |
} |
| 634 |
|
| 635 |
return $hash; |
| 636 |
} |
| 637 |
|
| 638 |
private static function deriveKey(string $hash, string $blockKey, string $algorithm = 'SHA512', int $keyBits = 256): string |
| 639 |
{ |
| 640 |
return (string) substr(str_pad(self::hash($algorithm, $hash . $blockKey), intdiv($keyBits, 8), "\x36"), 0, intdiv($keyBits, 8)); |
| 641 |
} |
| 642 |
|
| 643 |
private static function aesDecrypt(string $data, string $key, string $iv, int $keyBits = 256): string |
| 644 |
{ |
| 645 |
self::assertOpenSslAvailable(); |
| 646 |
$result = openssl_decrypt($data, 'aes-' . $keyBits . '-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); |
| 647 |
if ($result === false) { |
| 648 |
throw new Exception('Malformed XLSX encrypted data.'); |
| 649 |
} |
| 650 |
|
| 651 |
return $result; |
| 652 |
} |
| 653 |
|
| 654 |
private static function aesEncrypt(string $data, string $key, string $iv, int $keyBits = 256): string |
| 655 |
{ |
| 656 |
self::assertOpenSslAvailable(); |
| 657 |
$result = openssl_encrypt($data, 'aes-' . $keyBits . '-cbc', $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); |
| 658 |
if ($result === false) { |
| 659 |
throw new Exception('Could not encrypt XLSX data.'); |
| 660 |
} |
| 661 |
|
| 662 |
return $result; |
| 663 |
} |
| 664 |
|
| 665 |
private static function isSupportedProfile(int $keyBits, string $hashAlgorithm, int $hashSize): bool |
| 666 |
{ |
| 667 |
return in_array($keyBits, [128, 192, 256], true) |
| 668 |
&& isset(self::HASH_ALGORITHMS[$hashAlgorithm]) |
| 669 |
&& self::HASH_ALGORITHMS[$hashAlgorithm][1] === $hashSize; |
| 670 |
} |
| 671 |
|
| 672 |
private static function hash(string $algorithm, string $data): string |
| 673 |
{ |
| 674 |
return hash(self::HASH_ALGORITHMS[$algorithm][0], $data, true); |
| 675 |
} |
| 676 |
|
| 677 |
/** @return positive-int */ |
| 678 |
private static function hashSize(string $algorithm): int |
| 679 |
{ |
| 680 |
switch ($algorithm) { |
| 681 |
case 'SHA1': |
| 682 |
return 20; |
| 683 |
case 'SHA256': |
| 684 |
return 32; |
| 685 |
case 'SHA384': |
| 686 |
return 48; |
| 687 |
case 'SHA512': |
| 688 |
return 64; |
| 689 |
default: |
| 690 |
throw new Exception('Unsupported XLSX encryption profile.'); |
| 691 |
} |
| 692 |
} |
| 693 |
|
| 694 |
/** @return positive-int */ |
| 695 |
private static function keyLength(int $keyBits): int |
| 696 |
{ |
| 697 |
switch ($keyBits) { |
| 698 |
case 128: |
| 699 |
return 16; |
| 700 |
case 192: |
| 701 |
return 24; |
| 702 |
case 256: |
| 703 |
return 32; |
| 704 |
default: |
| 705 |
throw new Exception('Unsupported XLSX encryption profile.'); |
| 706 |
} |
| 707 |
} |
| 708 |
|
| 709 |
private static function iv(string $salt, string $blockKey, string $algorithm): string |
| 710 |
{ |
| 711 |
return substr(str_pad(self::hash($algorithm, $salt . $blockKey), self::BLOCK_SIZE, "\x36"), 0, self::BLOCK_SIZE); |
| 712 |
} |
| 713 |
|
| 714 |
private static function paddedLength(int $length): int |
| 715 |
{ |
| 716 |
return (int) (ceil($length / self::BLOCK_SIZE) * self::BLOCK_SIZE); |
| 717 |
} |
| 718 |
|
| 719 |
private static function assertOpenSslAvailable(): void |
| 720 |
{ |
| 721 |
if (!function_exists('openssl_encrypt') || !function_exists('openssl_decrypt')) { |
| 722 |
throw new Exception('XLSX encryption requires the OpenSSL extension.'); |
| 723 |
} |
| 724 |
} |
| 725 |
|
| 726 |
private static function packSize(int $size): string |
| 727 |
{ |
| 728 |
if ($size < 0) { |
| 729 |
throw new Exception('XLSX package is too large to encrypt.'); |
| 730 |
} |
| 731 |
|
| 732 |
return pack('V2', $size % 4294967296, intdiv($size, 4294967296)); |
| 733 |
} |
| 734 |
|
| 735 |
private static function unpackSize(string $data): int |
| 736 |
{ |
| 737 |
$unpackedSize = unpack('Vlow/Vhigh', $data); |
| 738 |
if ($unpackedSize === false || !isset($unpackedSize['low'], $unpackedSize['high']) || !is_int($unpackedSize['low']) || !is_int($unpackedSize['high'])) { |
| 739 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 740 |
} |
| 741 |
|
| 742 |
return self::sizeFromWords($unpackedSize['low'], $unpackedSize['high'], PHP_INT_SIZE, PHP_INT_MAX); |
| 743 |
} |
| 744 |
|
| 745 |
private static function sizeFromWords(int $low, int $high, int $integerSize, int $integerMax): int |
| 746 |
{ |
| 747 |
if ($integerSize < 8) { |
| 748 |
if ($high !== 0 || $low > $integerMax) { |
| 749 |
throw new Exception('Encrypted XLSX package is too large for this platform.'); |
| 750 |
} |
| 751 |
|
| 752 |
return $low; |
| 753 |
} |
| 754 |
if ($high > 0x7FFFFFFF) { |
| 755 |
throw new Exception('Encrypted XLSX package is too large for this platform.'); |
| 756 |
} |
| 757 |
|
| 758 |
return $low + $high * 4294967296; |
| 759 |
} |
| 760 |
|
| 761 |
/** @param resource $fileHandle */ |
| 762 |
private static function write($fileHandle, string $data): void |
| 763 |
{ |
| 764 |
if (fwrite($fileHandle, $data) !== strlen($data)) { |
| 765 |
throw new Exception('Could not write encrypted XLSX package.'); |
| 766 |
} |
| 767 |
} |
| 768 |
|
| 769 |
/** @param resource $fileHandle */ |
| 770 |
private static function read($fileHandle, int $length): string |
| 771 |
{ |
| 772 |
if ($length < 1) { |
| 773 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 774 |
} |
| 775 |
$data = fread($fileHandle, $length); |
| 776 |
if ($data === false || strlen($data) !== $length) { |
| 777 |
throw new Exception('Malformed encrypted XLSX package.'); |
| 778 |
} |
| 779 |
|
| 780 |
return $data; |
| 781 |
} |
| 782 |
|
| 783 |
private static function encryptionInfoXml(string $keyDataSalt, string $passwordSalt, string $encryptedVerifier, string $encryptedVerifierHash, string $encryptedKey, string $encryptedHmacKey, string $encryptedHmacValue, int $keyBits = 256, string $hashAlgorithm = 'SHA512', int $hashSize = 64, int $spinCount = 100000): string |
| 784 |
{ |
| 785 |
$base64 = static fn (string $value): string => base64_encode($value); |
| 786 |
|
| 787 |
return '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>' |
| 788 |
. '<encryption xmlns="http://schemas.microsoft.com/office/2006/encryption" xmlns:p="http://schemas.microsoft.com/office/2006/keyEncryptor/password">' |
| 789 |
. '<keyData saltSize="16" blockSize="16" keyBits="' . $keyBits . '" hashSize="' . $hashSize . '" cipherAlgorithm="AES" cipherChaining="ChainingModeCBC" hashAlgorithm="' . $hashAlgorithm . '" saltValue="' . $base64($keyDataSalt) . '"/>' |
| 790 |
. '<dataIntegrity encryptedHmacKey="' . $base64($encryptedHmacKey) . '" encryptedHmacValue="' . $base64($encryptedHmacValue) . '"/>' |
| 791 |
. '<keyEncryptors><keyEncryptor uri="http://schemas.microsoft.com/office/2006/keyEncryptor/password"><p:encryptedKey spinCount="' . $spinCount . '" saltSize="16" blockSize="16" keyBits="' . $keyBits . '" hashSize="' . $hashSize . '" cipherAlgorithm="AES" cipherChaining="ChainingModeCBC" hashAlgorithm="' . $hashAlgorithm . '" saltValue="' . $base64($passwordSalt) . '" encryptedVerifierHashInput="' . $base64($encryptedVerifier) . '" encryptedVerifierHashValue="' . $base64($encryptedVerifierHash) . '" encryptedKeyValue="' . $base64($encryptedKey) . '"/></keyEncryptor></keyEncryptors></encryption>'; |
| 792 |
} |
| 793 |
|
| 794 |
private static function dataSpacesVersion(): string |
| 795 |
{ |
| 796 |
if (!hex2bin('3c0000004d006900630072006f0073006f00660074002e0043006f006e007400610069006e00650072002e004400610074006100530070006100630065007300010000000100000001000000')) { |
| 797 |
throw new Exception('Could not generate XLSX encryption DataSpaces stream.'); |
| 798 |
} |
| 799 |
return hex2bin('3c0000004d006900630072006f0073006f00660074002e0043006f006e007400610069006e00650072002e004400610074006100530070006100630065007300010000000100000001000000'); |
| 800 |
} |
| 801 |
|
| 802 |
private static function primaryTransform(): string |
| 803 |
{ |
| 804 |
if (!hex2bin('58000000010000004c0000007b00460046003900410033004600300033002d0035003600450046002d0034003600310033002d0042004400440035002d003500410034003100430031004400300037003200340036007d004e0000004d006900630072006f0073006f00660074002e0043006f006e007400610069006e00650072002e0045006e006300720079007000740069006f006e005400720061006e00730066006f0072006d00000001000000010000000100000000000000000000000000000004000000')) { |
| 805 |
throw new Exception('Could not generate XLSX encryption DataSpaces stream.'); |
| 806 |
} |
| 807 |
return hex2bin('58000000010000004c0000007b00460046003900410033004600300033002d0035003600450046002d0034003600310033002d0042004400440035002d003500410034003100430031004400300037003200340036007d004e0000004d006900630072006f0073006f00660074002e0043006f006e007400610069006e00650072002e0045006e006300720079007000740069006f006e005400720061006e00730066006f0072006d00000001000000010000000100000000000000000000000000000004000000'); |
| 808 |
} |
| 809 |
|
| 810 |
private static function dataSpaceMap(): string |
| 811 |
{ |
| 812 |
if (!hex2bin('08000000010000006800000001000000000000002000000045006e0063007200790070007400650064005000610063006b00610067006500320000005300740072006f006e00670045006e006300720079007000740069006f006e004400610074006100530070006100630065000000')) { |
| 813 |
throw new Exception('Could not generate XLSX encryption DataSpaces stream.'); |
| 814 |
} |
| 815 |
return hex2bin('08000000010000006800000001000000000000002000000045006e0063007200790070007400650064005000610063006b00610067006500320000005300740072006f006e00670045006e006300720079007000740069006f006e004400610074006100530070006100630065000000'); |
| 816 |
} |
| 817 |
|
| 818 |
private static function strongEncryptionDataSpace(): string |
| 819 |
{ |
| 820 |
if (!hex2bin('0800000001000000320000005300740072006f006e00670045006e006300720079007000740069006f006e005400720061006e00730066006f0072006d000000')) { |
| 821 |
throw new Exception('Could not generate XLSX encryption DataSpaces stream.'); |
| 822 |
} |
| 823 |
return hex2bin('0800000001000000320000005300740072006f006e00670045006e006300720079007000740069006f006e005400720061006e00730066006f0072006d000000'); |
| 824 |
} |
| 825 |
|
| 826 |
/** @param array{keyDataSalt: string, passwordSalt: string, encryptedVerifier: string, encryptedVerifierHash: string, encryptedKey: string, encryptedHmacKey: string, encryptedHmacValue: string, spinCount: int, keyBits: int, hashAlgorithm: string, hashSize: int} $info */ |
| 827 |
private static function verifyIntegrity(array $info, string $secretKey, string $encryptedPackage): void |
| 828 |
{ |
| 829 |
$hmacKeyIv = self::iv($info['keyDataSalt'], self::BLOCK_KEY_HMAC_KEY, $info['hashAlgorithm']); |
| 830 |
$hmacValueIv = self::iv($info['keyDataSalt'], self::BLOCK_KEY_HMAC_VALUE, $info['hashAlgorithm']); |
| 831 |
$hmacKey = (string) substr(self::aesDecrypt($info['encryptedHmacKey'], $secretKey, $hmacKeyIv, $info['keyBits']), 0, $info['hashSize']); |
| 832 |
$expected = self::aesDecrypt($info['encryptedHmacValue'], $secretKey, $hmacValueIv, $info['keyBits']); |
| 833 |
if (!hash_equals(hash_hmac(self::HASH_ALGORITHMS[$info['hashAlgorithm']][0], $encryptedPackage, $hmacKey, true), (string) substr($expected, 0, $info['hashSize']))) { |
| 834 |
throw new Exception('Encrypted XLSX package integrity check failed.'); |
| 835 |
} |
| 836 |
} |
| 837 |
|
| 838 |
/** |
| 839 |
* @param array{keyDataSalt: string, passwordSalt: string, encryptedVerifier: string, encryptedVerifierHash: string, encryptedKey: string, encryptedHmacKey: string, encryptedHmacValue: string, spinCount: int, keyBits: int, hashAlgorithm: string, hashSize: int} $info |
| 840 |
* @param resource $input |
| 841 |
*/ |
| 842 |
private static function verifyIntegrityFile(array $info, string $secretKey, $input): void |
| 843 |
{ |
| 844 |
$hmacKeyIv = self::iv($info['keyDataSalt'], self::BLOCK_KEY_HMAC_KEY, $info['hashAlgorithm']); |
| 845 |
$hmacValueIv = self::iv($info['keyDataSalt'], self::BLOCK_KEY_HMAC_VALUE, $info['hashAlgorithm']); |
| 846 |
$hmacKey = (string) substr(self::aesDecrypt($info['encryptedHmacKey'], $secretKey, $hmacKeyIv, $info['keyBits']), 0, $info['hashSize']); |
| 847 |
$expected = self::aesDecrypt($info['encryptedHmacValue'], $secretKey, $hmacValueIv, $info['keyBits']); |
| 848 |
$hmac = hash_init(self::HASH_ALGORITHMS[$info['hashAlgorithm']][0], HASH_HMAC, $hmacKey); |
| 849 |
while (!feof($input)) { |
| 850 |
$data = fread($input, 8192); |
| 851 |
if ($data === false) { |
| 852 |
throw new Exception('Could not read encrypted XLSX package.'); |
| 853 |
} |
| 854 |
if ($data !== '') { |
| 855 |
hash_update($hmac, $data); |
| 856 |
} |
| 857 |
} |
| 858 |
if (!hash_equals(hash_final($hmac, true), (string) substr($expected, 0, $info['hashSize']))) { |
| 859 |
throw new Exception('Encrypted XLSX package integrity check failed.'); |
| 860 |
} |
| 861 |
} |
| 862 |
} |
| 863 |
|
