RSA iOS encrypt & PHP decrypt - php

Question

As referring to this link http://blog.iamzsx.me/show.html?id=155002, I generated a pair of key using
$ openssl req -x509 -out public_key.der -outform der -new -newkey rsa:1024 -keyout private_key.pem -days 3650
this command. Then I get private_key.pem & public_key.der.
I follow the implementation what I get the encrypted data is
<ceaedf05 f39b69ab 8618f859 599926e9 c18d9233 342c58e0 534b66af 8b33dda3 375d6a11 b95ad821 11549637 ce4c26dc 760169c6 04096aff 9ec48938 1c6b149f 8180f9bb 8e1337ce 2b492af2 e0464e4c 9ab7aabd 9da53caf 1b5e5277 3c708b43 cb6515ee c9a18b02 4941416c 7f1e36d3 dcd3705b 66f8a159 ab8a7a3f a9db8306>
but what I want is
dXXEEADvRDdk4QVM6TU9dyYtuHe8RVzP3KsWAoDDSQ2w+NELVPOv4mSVW1jIhEhb+pLsmOvLzGIW1/2qkp91M1UoPuhgplV2JEgP8EvcBn8EY43n7wVASGP9heRK0lYMfENP54f35+GFP68nU5zbrmX0IN6DGGGSNdSewzLb6s4=
Actually what I want is the functions below:
in iOS:
- (NSString *)encryptedString:(NSString *)plainText
in PHP:
function decrypted_string()
{
$encrypted_string = $_POST['encrypted_string'];
// implementation
return $plain_text;
}
How can I implement these functions?
I already googled for it, unfortunately, there is no solution that I want. Hopefully can get help in here. Thanks in advance.

Answer 1

You need to base64 encode the NSData before sending to php. See the answer for the following post:
Creating a base-64 string from NSData
On php end, you can use openssl_private_decrypt to decrypt. Reference below:
http://php.net/manual/en/function.openssl-private-decrypt.php
Sample:
<?php
$fp=fopen("/path/to/private_key.pem","r");
$priv_key=fread($fp,8192);
fclose($fp);
$res = openssl_get_privatekey($priv_key, "myPassword");
$data = $_POST['encrypted_string'];
if (openssl_private_decrypt(base64_decode($data), $decrypted, $res))
echo "Decrypted:$decrypted";
?>

Answer 2

Expanding on neubert's answer..
<?php
include('Crypt/RSA.php');
$rsa = new Crypt_RSA();
$rsa->setPassword('abc123');
$rsa->loadKey('-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,927035AD39FA7CED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-----END RSA PRIVATE KEY-----');
$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
echo $rsa->decrypt(base64_decode('qieklzzWct0ab7UOows+uvlaI5VLEHwIED4+O9KjVKopGTPIVaB8ioSUNZKnh5LUepmc/gowrp4pM1X??J+e+rPlwqI98d56ijdWuDOOojGR5VCNilztPSxI6PIpQeL58y+B5EVUWv49dcTuGwuRiU/FL8APkNqdEE??k43SLKyhY7w='));

Answer 3

My recommndation: use phpseclib, a pure PHP RSA implementation. eg.
<?php
include('Crypt/RSA.php');
$rsa = new Crypt_RSA();
$rsa->setPassword('abc123');
$rsa->loadKey('-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,927035AD39FA7CED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-----END RSA PRIVATE KEY-----');
$rsa->setEncryptionMode(CRYPT_RSA_ENCRYPTION_PKCS1);
echo $rsa->decrypt(base64_decode('qieklzzWct0ab7UOows+uvlaI5VLEHwIED4+O9KjVKopGTPIVaB8ioSUNZKnh5LUepmc/gowrp4pM1X??J+e+rPlwqI98d56ijdWuDOOojGR5VCNilztPSxI6PIpQeL58y+B5EVUWv49dcTuGwuRiU/FL8APkNqdEE??k43SLKyhY7w='));