Implement encryptSecretKey

Allow encrypting a decrypted secret key, which is especially useful for
generating a new encrypted secret key.  Defaults to AES256, S2K
iter+salt SHA512, always uses s2k_useage 254 with sha1 integrity
protection of the encrypted key material.

Also add an example to parallel keygen.php that generates a key and then
encrypts it with a passphrase.
This commit is contained in:
Stephen Paul Weber 2019-09-10 21:31:06 -05:00
parent 67aba78699
commit d27d30a352
No known key found for this signature in database
GPG Key ID: D11C2911CE519CDE
3 changed files with 61 additions and 0 deletions

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@ -0,0 +1,28 @@
<?php
@include_once dirname(__FILE__).'/../vendor/autoload.php';
require_once dirname(__FILE__).'/../lib/openpgp.php';
require_once dirname(__FILE__).'/../lib/openpgp_crypt_rsa.php';
require_once dirname(__FILE__).'/../lib/openpgp_crypt_symmetric.php';
$rsa = new \phpseclib\Crypt\RSA();
$k = $rsa->createKey(512);
$rsa->loadKey($k['privatekey']);
$nkey = new OpenPGP_SecretKeyPacket(array(
'n' => $rsa->modulus->toBytes(),
'e' => $rsa->publicExponent->toBytes(),
'd' => $rsa->exponent->toBytes(),
'p' => $rsa->primes[2]->toBytes(),
'q' => $rsa->primes[1]->toBytes(),
'u' => $rsa->coefficients[2]->toBytes()
));
$uid = new OpenPGP_UserIDPacket('Test <test@example.com>');
$wkey = new OpenPGP_Crypt_RSA($nkey);
$m = $wkey->sign_key_userid(array($nkey, $uid));
$m[0] = OpenPGP_Crypt_Symmetric::encryptSecretKey("password", $nkey);
// Serialize encrypted private key
print $m->to_bytes();

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@ -75,6 +75,31 @@ class OpenPGP_Crypt_Symmetric {
return NULL; /* If we get here, we failed */ return NULL; /* If we get here, we failed */
} }
public static function encryptSecretKey($pass, $packet, $symmetric_algorithm=9) {
$packet = clone $packet; // Do not mutate original
$packet->s2k_useage = 254;
$packet->symmetric_algorithm = $symmetric_algorithm;
list($cipher, $key_bytes, $key_block_bytes) = self::getCipher($packet->symmetric_algorithm);
if(!$cipher) throw new Exception("Unsupported cipher");
$material = '';
foreach(OpenPGP_SecretKeyPacket::$secret_key_fields[$packet->algorithm] as $field) {
$f = $packet->key[$field];
$material .= pack('n', OpenPGP::bitlength($f)) . $f;
unset($packet->key[$field]);
}
$material .= hash('sha1', $material, true);
$iv = Random::string($key_block_bytes);
if(!$packet->s2k) $packet->s2k = new OpenPGP_S2K(Random::string(8));
$cipher->setKey($packet->s2k->make_key($pass, $key_bytes));
$cipher->setIV($iv);
$packet->encrypted_data = $iv . $cipher->encrypt($material);
return $packet;
}
public static function decryptSecretKey($pass, $packet) { public static function decryptSecretKey($pass, $packet) {
$packet = clone $packet; // Do not mutate orinigal $packet = clone $packet; // Do not mutate orinigal
@ -97,6 +122,7 @@ class OpenPGP_Crypt_Symmetric {
if($chk != $mkChk) return NULL; if($chk != $mkChk) return NULL;
} }
$packet->s2k = NULL;
$packet->s2k_useage = 0; $packet->s2k_useage = 0;
$packet->symmetric_algorithm = 0; $packet->symmetric_algorithm = 0;
$packet->encrypted_data = NULL; $packet->encrypted_data = NULL;

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@ -143,6 +143,13 @@ class Decryption extends PHPUnit_Framework_TestCase {
$this->assertSame(!!$skey, true); $this->assertSame(!!$skey, true);
} }
public function testEncryptSecretKeyRoundtrip() {
$key = OpenPGP_Message::parse(file_get_contents(dirname(__FILE__) . '/data/helloKey.gpg'));
$enkey = OpenPGP_Crypt_Symmetric::encryptSecretKey("password", $key[0]);
$skey = OpenPGP_Crypt_Symmetric::decryptSecretKey("password", $enkey);
$this->assertEquals($key[0], $skey);
}
public function testAlreadyDecryptedSecretKey() { public function testAlreadyDecryptedSecretKey() {
$this->expectException(Exception::class); $this->expectException(Exception::class);
$this->expectExceptionMessage("Data is already unencrypted"); $this->expectExceptionMessage("Data is already unencrypted");