Using RSA KeyPair on a C # server and PHP client

Question

I have a C # server that will generate an RSA KeyValue Pair. The public key will be sent to the PHP client, which will then encrypt some data and send it to the server. Then the server is decrypted using the private key that it has.

I do this using the following code in C # -

CspParameters cspParams = new CspParameters { ProviderType = 1 };

RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider(1024, cspParams);

string publicKey = Convert.ToBase64String(rsaProvider.ExportCspBlob(false));
string privateKey = Convert.ToBase64String(rsaProvider.ExportCspBlob(true));

Now I need to pass the public key generated by the PHP client. But the problem is that the key string generated here in C # is not recognized by PHP when I use it in a function, as shown below -

public function encrypt($data)
{
    $pubkey = 'BgIAAACkAABSU0ExAAIAAAEAAQBdZ3klDbVjH8oiBtGzHIMixo/TKPlv492kuau9chnARvkpxaRd8Qa82kIF2AvrEllhzjD07UHkVxoVZA2aYN+t'
    $pubKey4 = openssl_get_publickey(  $pubkey );

    openssl_public_encrypt($data, $encrypted, $pubKey4 )

}

Function

openssl_public_encrypt() shows a warning like this:

Warning: openssl_public_encrypt (): key parameter is not a valid key in C: \ wamp \ www \ rsa \ index.php

, , , PHP.

X509 .

Answer 1

3v4l, openssl_get_publickey() false. PEM.

, , , libsodium.

Libsodium - NaCl, , , , .., Daniel J. Bernstein, Tanja Lange Peter Schwabe ( , ).

Libsodium - NaCl, (, scrypt).

Libsodium #

using Sodium;

// snip

var keypair = PublicKeyBox.GenerateKeyPair();
string secretKey = Convert.ToBase64String(keypair.PrivateKey);
string publicKey = Convert.ToBase64String(keypair.PublicKey);

libsodium.NET .

PHP #

<?php
$decoded = base64_decode($encoded_publickey);
define('YOUR_RAW_BINARY_CSHARP_PUBLIC_KEY', $decoded);

$php_keypair = \Sodium\crypto_box_keypair();
$php_public = \Sodium\crypto_box_publickey($php_keypair);
$php_secret = \Sodium\crypto_box_secretkey($php_keypair);

$nonce = \Sodium\randombytes_buf(\Sodium\CRYPTO_BOX_NONCEBYTES);

$message_keypair = \Sodium\crypto_box_keypair_from_secretkey_and_publickey(
    $php_secret,
    YOUR_RAW_BINARY_CSHARP_PUBLIC_KEY
);
$encrypted = \Sodium\crypto_box(
    $message,
    $nonce,
    $message_keypair
);

$encrypted ; # $nonce, $encrypted $php_public ( ) $encrypted, , $message.

PHP libsodium .

# PHP

<?php
$anon_msg = \Sodium\crypto_box_seal($message, YOUR_RAW_BINARY_CSHARP_PUBLIC_KEY);

crypto_box_seal .

Answer 2

, 512- $pubkey PHP?

, OpenSSH, , ( phpseclib):

<?php
include('Crypt/RSA.php');

$a = 'BgIAAACkAABSU0ExAAIAAAEAAQBdZ3klDbVjH8oiBtGzHIMixo/TKPlv492kuau9chnARvkpxaRd8Qa82kIF2AvrEllhzjD07UHkVxoVZA2aYN+t';
$a = base64_decode($a);

echo parseCSBBlob($a);

// https://msdn.microsoft.com/en-us/library/windows/desktop/aa375601(v=vs.85).aspx
function parseCSBBlob($str) {
    // from https://msdn.microsoft.com/en-us/library/windows/desktop/aa387453(v=vs.85).aspx
    extract(unpack('atype/aversion/vreserved/Valgo', $str));
    if (ord($type) != 6) { // 6 == PUBLICKEYBLOB
        return false;
    }
    //https://msdn.microsoft.com/en-us/library/windows/desktop/aa375549(v=vs.85).aspx
    if ($algo != 0x0000a400) { // 0x0000a400 == CALG_RSA_KEYX
        return false;
    }
    $str = substr($str, 8); // aavV
    extract(unpack('Vmagic/Vbitlen/Vpubexp', $str));
    if ($magic != 0x31415352) { // RSA1
        return false;
    }
    $str = substr($str, 12); // VVV
    if (strlen($str) != $bitlen / 8) {
        return false;
    }
    $str = strrev($str);

    $rsa = new Crypt_RSA();
    $rsa->loadKey(array(
        'e' => new Math_BigInteger($pubexp, 256),
        'n' => new Math_BigInteger($str, 256)
    ));
    return $rsa;
}

$rsa, parseCSBBlob.

$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
define('CRYPT_RSA_PKCS15_COMPAT', true);
$rsa->encrypt($data);