Files
CoreLibs-Composer-All/src/Security/AsymmetricAnonymousEncryption.php
2024-12-24 12:49:49 +09:00

409 lines
11 KiB
PHP

<?php
/**
* very simple asymmetric encryption
* Better use:
* https://paragonie.com/project/halite
* https://github.com/paragonie/halite
*
* current code is just to encrypt and decrypt
*
* must use a valid encryption key created with
* Secruty\CreateKey class
*/
declare(strict_types=1);
namespace CoreLibs\Security;
use CoreLibs\Security\CreateKey;
use SodiumException;
class AsymmetricAnonymousEncryption
{
/** @var AsymmetricAnonymousEncryption self instance */
private static AsymmetricAnonymousEncryption $instance;
/** @var ?string key pair which holds secret and public key, needed for encryption */
private ?string $key_pair = null;
/** @var ?string public key, needed for decryption
* if not set but key_pair set, this will be extracted from key pair */
private ?string $public_key = null;
/**
* init class
* if key not passed, key must be set with createKey
*
* @param string|null $key_pair
* @param string|null $public_key
*/
public function __construct(
#[\SensitiveParameter]
string|null $key_pair = null,
string|null $public_key = null
) {
if ($public_key !== null) {
$this->setPublicKey($public_key);
}
if ($key_pair !== null) {
$this->setKeyPair($key_pair);
if (empty($public_key)) {
$public_key = CreateKey::getPublicKey($key_pair);
$this->setPublicKey($public_key);
}
}
}
/**
* Returns the singleton self object.
* For function wrapper use
*
* @param string|null $key_pair
* @param string|null $public_key
* @return AsymmetricAnonymousEncryption object
*/
public static function getInstance(
#[\SensitiveParameter]
string|null $key_pair = null,
string|null $public_key = null
): self {
// new if no instsance or key is different
if (
empty(self::$instance) ||
self::$instance->key_pair != $key_pair ||
self::$instance->public_key != $public_key
) {
self::$instance = new self($key_pair, $public_key);
}
return self::$instance;
}
/**
* clean up
*/
public function __destruct()
{
if (empty($this->key_pair)) {
return;
}
try {
// would set it to null, but we we do not want to make key null
sodium_memzero($this->key_pair);
return;
} catch (SodiumException) {
// empty catch
}
if (is_null($this->key_pair)) {
return;
}
$zero = str_repeat("\0", mb_strlen($this->key_pair, '8bit'));
$this->key_pair = $this->key_pair ^ (
$zero ^ $this->key_pair
);
unset($zero);
unset($this->key_pair); /** @phan-suppress-current-line PhanTypeObjectUnsetDeclaredProperty */
}
/* ************************************************************************
* MARK: PRIVATE
* *************************************************************************/
/**
* Create the internal key pair in binary
*
* @param ?string $key_pair
* @return string
* @throws \UnexpectedValueException key pair empty
* @throws \UnexpectedValueException invalid hex key pair
* @throws \RangeException key pair not correct size
*/
private function createKeyPair(
#[\SensitiveParameter]
?string $key_pair
): string {
if (empty($key_pair)) {
throw new \UnexpectedValueException('Key pair cannot be empty');
}
try {
$key_pair = CreateKey::hex2bin($key_pair);
} catch (SodiumException $e) {
sodium_memzero($key_pair);
throw new \UnexpectedValueException('Invalid hex key pair: ' . $e->getMessage());
}
if (mb_strlen($key_pair, '8bit') !== SODIUM_CRYPTO_BOX_KEYPAIRBYTES) {
sodium_memzero($key_pair);
throw new \RangeException(
'Key pair is not the correct size (must be '
. SODIUM_CRYPTO_BOX_KEYPAIRBYTES . ' bytes long).'
);
}
return $key_pair;
}
/**
* create the internal public key in binary
*
* @param ?string $public_key
* @return string
* @throws \UnexpectedValueException public key empty
* @throws \UnexpectedValueException invalid hex key
* @throws \RangeException invalid key length
*/
private function createPublicKey(?string $public_key): string
{
if (empty($public_key)) {
throw new \UnexpectedValueException('Public key cannot be empty');
}
try {
$public_key = CreateKey::hex2bin($public_key);
} catch (SodiumException $e) {
sodium_memzero($public_key);
throw new \UnexpectedValueException('Invalid hex public key: ' . $e->getMessage());
}
if (mb_strlen($public_key, '8bit') !== SODIUM_CRYPTO_BOX_PUBLICKEYBYTES) {
sodium_memzero($public_key);
throw new \RangeException(
'Public key is not the correct size (must be '
. SODIUM_CRYPTO_BOX_PUBLICKEYBYTES . ' bytes long).'
);
}
return $public_key;
}
/**
* encrypt a message asymmetric with a bpulic key
*
* @param string $message
* @param ?string $public_key
* @return string
* @throws \UnexpectedValueException create encryption failed
* @throws \UnexpectedValueException convert to base64 failed
*/
private function asymmetricEncryption(
#[\SensitiveParameter]
string $message,
?string $public_key
): string {
$public_key = $this->createPublicKey($public_key);
try {
$encrypted = sodium_crypto_box_seal($message, $public_key);
} catch (SodiumException $e) {
sodium_memzero($message);
throw new \UnexpectedValueException("Create encrypted message failed: " . $e->getMessage());
}
sodium_memzero($message);
try {
$result = sodium_bin2base64($encrypted, SODIUM_BASE64_VARIANT_ORIGINAL);
} catch (SodiumException $e) {
sodium_memzero($encrypted);
throw new \UnexpectedValueException("bin2base64 failed: " . $e->getMessage());
}
sodium_memzero($encrypted);
return $result;
}
/**
* decrypt a message that is asymmetric encrypted with a key pair
*
* @param string $message
* @param ?string $key_pair
* @return string
* @throws \UnexpectedValueException message string empty
* @throws \UnexpectedValueException base64 decoding failed
* @throws \UnexpectedValueException decryption failed
* @throws \UnexpectedValueException could not decrypt message
*/
private function asymmetricDecryption(
#[\SensitiveParameter]
string $message,
#[\SensitiveParameter]
?string $key_pair
): string {
if (empty($message)) {
throw new \UnexpectedValueException('Encrypted string cannot be empty');
}
$key_pair = $this->createKeyPair($key_pair);
try {
$result = sodium_base642bin($message, SODIUM_BASE64_VARIANT_ORIGINAL);
} catch (SodiumException $e) {
sodium_memzero($message);
sodium_memzero($key_pair);
throw new \UnexpectedValueException("base642bin failed: " . $e->getMessage());
}
sodium_memzero($message);
$plaintext = false;
try {
$plaintext = sodium_crypto_box_seal_open($result, $key_pair);
} catch (SodiumException $e) {
sodium_memzero($message);
sodium_memzero($key_pair);
sodium_memzero($result);
throw new \UnexpectedValueException("Decrypting message failed: " . $e->getMessage());
}
sodium_memzero($key_pair);
sodium_memzero($result);
if (!is_string($plaintext)) {
throw new \UnexpectedValueException('Invalid key pair');
}
return $plaintext;
}
/* ************************************************************************
* MARK: PUBLIC
* *************************************************************************/
/**
* sets the private key for encryption
*
* @param string $key_pair Key pair in hex
* @return AsymmetricAnonymousEncryption
* @throws \UnexpectedValueException key pair empty
*/
public function setKeyPair(
#[\SensitiveParameter]
string $key_pair
): AsymmetricAnonymousEncryption {
if (empty($key_pair)) {
throw new \UnexpectedValueException('Key pair cannot be empty');
}
// check if valid;
$this->createKeyPair($key_pair);
// set new key pair
$this->key_pair = $key_pair;
sodium_memzero($key_pair);
// set public key if not set
if (empty($this->public_key)) {
$this->public_key = CreateKey::getPublicKey($this->key_pair);
// check if valid
$this->createPublicKey($this->public_key);
}
return $this;
}
/**
* check if set key pair matches given one
*
* @param string $key_pair
* @return bool
*/
public function compareKeyPair(
#[\SensitiveParameter]
string $key_pair
): bool {
return $this->key_pair === $key_pair;
}
/**
* get the current set key pair, null if not set
*
* @return string|null
*/
public function getKeyPair(): ?string
{
return $this->key_pair;
}
/**
* sets the public key for decryption
* if only key pair exists Security\Create::getPublicKey() can be used to
* extract the public key from the key pair
*
* @param string $public_key Public Key in hex
* @return AsymmetricAnonymousEncryption
* @throws \UnexpectedValueException public key empty
*/
public function setPublicKey(string $public_key): AsymmetricAnonymousEncryption
{
if (empty($public_key)) {
throw new \UnexpectedValueException('Public key cannot be empty');
}
// check if valid
$this->createPublicKey($public_key);
$this->public_key = $public_key;
sodium_memzero($public_key);
return $this;
}
/**
* check if the set public key matches the given one
*
* @param string $public_key
* @return bool
*/
public function comparePublicKey(string $public_key): bool
{
return $this->public_key === $public_key;
}
/**
* get the current set public key, null if not set
*
* @return string|null
*/
public function getPublicKey(): ?string
{
return $this->public_key;
}
/**
* Encrypt a message with a public key
* static version
*
* @param string $message Message to encrypt
* @param string $public_key Public key in hex to encrypt message with
* @return string Encrypted message as hex string
*/
public static function encryptKey(
#[\SensitiveParameter]
string $message,
string $public_key
): string {
return self::getInstance()->asymmetricEncryption($message, $public_key);
}
/**
* Encrypt a message
*
* @param string $message Message to ecnrypt
* @return string Encrypted message as hex string
*/
public function encrypt(
#[\SensitiveParameter]
string $message
): string {
return $this->asymmetricEncryption($message, $this->public_key);
}
/**
* decrypt a message with a key pair
* static version
*
* @param string $message Message to decrypt in hex
* @param string $key_pair Key pair in hex to decrypt the message with
* @return string Decrypted message
*/
public static function decryptKey(
#[\SensitiveParameter]
string $message,
#[\SensitiveParameter]
string $key_pair
): string {
return self::getInstance()->asymmetricDecryption($message, $key_pair);
}
/**
* decrypt a message
*
* @param string $message Message to decrypt in hex
* @return string Decrypted message
*/
public function decrypt(
#[\SensitiveParameter]
string $message
): string {
return $this->asymmetricDecryption($message, $this->key_pair);
}
}
// __END__