Code Samples: May 2017

Sunday, May 28, 2017

PHP Script: Call Method Dynamically

PHP Script: Call Method Dynamically. Below is PHP Script which describes the full process:

<?php
$fnc = "canCall";
if (!is_callable($fnc)) {
    echo "Cant call method: $fnc <BR>";
} else {
    echo "Return from method $fnc: " . $fnc(15) . "<BR>";
}

$fnc = "canCall2";
if (!is_callable($fnc)) {
    echo "Cant call method: $fnc <BR>";
} else {
    echo "Return from method $fnc: " . $fnc(15) . "<BR>";
}

function canCall($a = 10)
{
    return $a * 5;
}

$caller_class = new CallerClass();
$caller_class->check();

class CallerClass
{
    private $for_method1 = 10;

    public function check()
    {
        $fnc = "method1";
        if (!is_callable(array(&$this, $fnc))) {
            echo "$fnc is not callable function";
        } else {
            $this->{"for_method1"} = 20;
            echo "Return from $fnc:" . $this->{$fnc}() . "<BR>";
        }

        $fnc = "method2";
        if (!is_callable(array(&$this, $fnc))) {
            echo "$fnc is not callable function";
        } else {
            echo "Return from $fnc:" . $this->{$fnc}() . "<BR>";
        }
    }

    public function method1()
    {
        return "From method 1 <$this->for_method1>";
    }
}

?>

Which will output as below:

Return from method canCall: 75
Cant call method: canCall2
Return from method1:From method 1 <20>
method2 is not callable function

PHP Script: Define Variable Dynamically

PHP Script: Define Variable Dynamically. Its easy:

${"variable"} = "Variable defined dynamically";

echo $variable;

Will output:

Variable defined dynamically

And in class file (both static and instance scope):

SomeClass::test();
SomeClass::test2();

$class = new SomeClass();
$class->test3();

class SomeClass {
    static $xxx = null;

    static function test() {
        self::${"xxx"} = "Value";
    }

    static function test2() {
        echo self::${"xxx"} . "::" . self::$xxx;
    }

    function test3() {
        $this->{"yyyy"} = "Value of YYYY";
        echo "<BR>" . $this->yyyy;
    }
}

How to PHP call another page and get output as variable?

How to PHP call another page and get output as variable? it's easy. We can do it in two way. First way is processing via ob_... and second way is get content in a variable and execute eval function.

Below is a PHP Script which will describes both way:

<?php
ob_start();
${"variable"} = array("as_array" => "Test variable value in array #Method 1");
require 'content.txt';
$output = ob_get_clean();
echo $output;

${"variable"} = array("as_array" => "Test variable value in array #Method 2");
$file = file_get_contents('content.txt');
$content = eval("?>$file");
echo $content;

Content of "content.txt" file below:

<div style="margin: 10px; border: 1px solid red; padding: 10px;">
    <h3>HI, Time = <?= date("d/m/Y h:i A") ?></h3>
    <h4><?= $variable["as_array"] ?></h4>
    <table>
        <tr>
            <td>TABLE > TR > TD</td>
        </tr>
    </table>
</div>

And output of above PHP Script below:

HI, Time = 28/05/2017 02:56 PM

Test variable value in array #Method 1

TABLE > TR > TD

HI, Time = 28/05/2017 02:56 PM

Test variable value in array #Method 2

TABLE > TR > TD

Saturday, May 27, 2017

Git Merge Working Branch With Remove Branch

At first you nee to update your local branch using below command. It may better your have no local changes.

git pull

Then execute following command to update current branch with specific remote branch:

git merge remotes/origin/remote_branch

Sometimes it may prompt the following dialog:

Then you have to follow the below steps:

1. Press `i` to enable edit mode
2. Use down cursor go to the last line and introduce new line
3. Put some comments
4. Press `Esc` then `:wq!` and hit Enter key
5. You are done with merge
6. And finally execute "git push" to push changes

Sometime it may told you that some conflict occurred with the list of files, then you need to merge them before do merge.

After conflict occurred executed command "git merge --abort" to abort current merge request and then merge conflict before try again merge.

The simplest solution is fetch conflict file from the branch from where you want to merge using below command:

git checkout origin/branch_name app/directory/file.name

and push all files and then try again, i think it helps.

Sometimes it may need to stash your local changes before execute "git merge ..." command:

git stash

And after execute "git merge ..." execute below command to unstash changes:

git stash apply stash@{0}

To reset your current working branch:

git reset --hard (will move to previous commit)

And finally if you want to clear all untracked files execute:

git clean -fd

Stripe Payment API: Create Charge Or Payment

You need a Token (Saved credit card instance) to create a Payment which is known as Charge in Stripe API. Creating Charge in Stripe is equal to creating a Payment.

Payment API documentation:
https://stripe.com/docs/api#charges

<?php
function createCharge()
{
    $token = CreateToken::create();

    if ($token["code"] != 200) {
        StripeCharge::prettyPrint($token["response"]);
        exit;
    }

    $params = array(
        "amount" => "200",
        "currency" => "aud",
        "source" => $token["response"]->id,
        "description" => "Some description against charge/payment"
    );
    $create = StripeCharge::create($params);
    StripeCharge::prettyPrint($create);
}
createCharge();

class StripeCharge {
    private static $key = "sk_test_...";

    static function create($params)
    {
        $url = "https://api.stripe.com/v1/charges";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "POST", null, $params, $headers);
    }

    static function prettyPrint($data)
    {
        echo "<pre>";
        print_r($data);
        echo "</pre>";
    }
}

Output below:

Friday, May 26, 2017

Stripe Payment API: Create Get Edit Delete Customer

You can create Customer in Stripe using API. You can profile source when you create the Customer. Here source is payment source, Such you can create a Credit Card Token and provide reference as source. To create Credit Card Token follow below link:

http://pritomkumar.blogspot.com/2017/05/stripe-payment-api-create-token-using.html

And below link for API details:
https://stripe.com/docs/api#create_customer

Below is a PHP Script that will Create Get And Delete Customer From Stripe.

<?php
$params = array(
    "email" => "customer_3@pritom.com",

    "source" => "token_id_using_above_link"

 );
$create = StripeCustomer::create($params);
StripeCustomer::prettyPrint($create);

if ($create["code"] == 200) {
    $get = StripeCustomer::get($create["response"]->id);
    StripeCustomer::prettyPrint($get);

    $delete = StripeCustomer::delete($create["response"]->id);
    StripeCustomer::prettyPrint($delete);
}

class StripeCustomer {
    private static $key = "sk_test_............";

    static function create($params)
    {
        $url = "https://api.stripe.com/v1/customers";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "POST", null, $params, $headers);
    }

    static function get($id)
    {
        $url = "https://api.stripe.com/v1/customers/$id";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "GET", null, null, $headers);
    }

    static function delete($id)
    {
        $url = "https://api.stripe.com/v1/customers/$id";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "DELETE", null, null, $headers);
    }

    static function prettyPrint($data)
    {
        echo "<pre>";
        print_r($data);
        echo "</pre>";
    }
}

Below is output of the Script above:

CREATE REQUEST RESPONSE:

GET REQUEST RESPONSE
Array
(
    [code] => 200
    [response] => stdClass Object
        (
            [id] => cus_Aj4kNrfMs3ivE8
            [object] => customer
            [account_balance] => 0
            [created] => 1495782666
            [currency] =>
            [default_source] =>
            [delinquent] =>
            [description] =>
            [discount] =>
            [email] => customer_3@pritom.com
            [livemode] =>
            [metadata] => stdClass Object
                (
                )

            [shipping] =>
            [sources] => stdClass Object
                (
                    [object] => list
                    [data] => Array
                        (
                        )

                    [has_more] =>
                    [total_count] => 0
                    [url] => /v1/customers/cus_Aj4kNrfMs3ivE8/sources
                )

            [subscriptions] => stdClass Object
                (
                    [object] => list
                    [data] => Array
                        (
                        )

                    [has_more] =>
                    [total_count] => 0
                    [url] => /v1/customers/cus_Aj4kNrfMs3ivE8/subscriptions
                )

        )

)
DELETE REQUEST RESULT
Array
(
    [code] => 200
    [response] => stdClass Object
        (
            [deleted] => 1
            [id] => cus_Aj4kNrfMs3ivE8
        )

)

Stripe Payment API: Create Token Using Credit Card Details

What is need at first is to you have need an Stripe account. If you haven't that yet follow the link https://dashboard.stripe.com/register to create one. After that you need to collect API Key from Stripe portal. Below is a screenshot attached to describe how API Key collected.

Next step is to collect credit card details from end user and sent them to stripe to create a token to use further. Below is a full PHP Script that create and retrieve token from Stripe end.

Below are list of test credit cards for Stripe:
https://stripe.com/docs/testing

<?php
$params = array(
    "card" => array(
        "name" => "Card Name",
        "number" => "4242424242424242",
        "exp_month" => "12",
        "exp_year" =>  "19",
        "cvc" => "123"
    )
);

$create = CreateToken::create($params);
CreateToken::prettyPrint($create);

if ($create["code"] == 200) {
    $get = CreateToken::get($create["response"]->id);
    CreateToken::prettyPrint($get);
}

class CreateToken {
    private static $key = "sk_test_...................";

    static function create($params)
    {
        $url = "https://api.stripe.com/v1/tokens";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "POST", null, $params, $headers);
    }

    static function get($id)
    {
        $url = "https://api.stripe.com/v1/tokens/$id";

        $headers[] = "Authorization: Bearer " . self::$key;
        $headers[] = "Content-Type: application/x-www-form-urlencoded";

        return makeCurlCall($url, "GET", null, null, $headers);
    }

    static function prettyPrint($data)
    {
        echo "<pre>";
        print_r($data);
        echo "</pre>";
    }
}

Below is output for error response:
Array
(
    [code] => 402
    [response] => stdClass Object
        (
            [error] => stdClass Object
                (
                    [message] => Your card number is incorrect.
                    [type] => card_error
                    [param] => number
                    [code] => incorrect_number
                )
        )
)

Below is output for success response:

Array
(
    [code] => 200
    [response] => stdClass Object
        (
            [id] => tok_1ANblQFIwfarG3vBaSA6dNaX
            [object] => token
            [card] => stdClass Object
                (
                    [id] => card_1ANblQFIwfarG3vBdjdo6nd5
                    [object] => card
                    [address_city] =>
                    [address_country] =>
                    [address_line1] =>
                    [address_line1_check] =>
                    [address_line2] =>
                    [address_state] =>
                    [address_zip] =>
                    [address_zip_check] =>
                    [brand] => Visa
                    [country] => US
                    [cvc_check] => unchecked
                    [dynamic_last4] =>
                    [exp_month] => 12
                    [exp_year] => 2019
                    [fingerprint] => SmsX0otFJxkdwdrG
                    [funding] => credit
                    [last4] => 4242
                    [metadata] => stdClass Object
                        (
                        )
                    [name] => Card Name
                    [tokenization_method] =>
                )
            [client_ip] => 103.59.179.132
            [created] => 1495779452
            [livemode] =>
            [type] => card
            [used] =>
        )
)

Thursday, May 25, 2017

PHP Script - detect whether running under Linux or Windows?

PHP script - detect whether running under Linux or Windows or other Operating System? I don't have so much knowledge but can overcome with some solution. "PHP_OS" will solve this issue. Below is function to check if OS is Windows or not:

if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
echo 'Windows!';
} else {
echo 'Other Than Windows!';
}

PHP_OS will output below list of Operating System, not full list but I think it's almost all.

CYGWIN_NT-5.1
Darwin
FreeBSD
HP-UX
IRIX64
Linux
NetBSD
OpenBSD
SunOS
Unix
WIN32

WINNT

Windows

You can see on Wikipedia for more information.

Wednesday, May 24, 2017

PHP Encrypt Data With OpenSSL Public Key And Decrypt With OpenSSL Private Key

Below is a PHP code snippet to encrypt data with a public key and then again decrypt the encrypted data with a private key.

If you have fetched the problem "error:0406D06E:rsa routines:RSA_padding_add_PKCS1_type_2:data too large for key size" then use the below code snippet to overcome this problem.

It's a good solution to handle big size data, but don't try too big size data with this method actually when you post file.
Raw data is fine.

$data = "Large data to test. Large data to test. Large data to test. Large data to test.";
$data = $data . $data . $data . $data . $data . $data . $data . $data;
$data = $data . $data . $data . $data . $data . $data . $data . $data;
encryptAndDecrypt($data);

function encryptAndDecrypt($data)
{
    echo "Original data length=" . strlen($data) . "<BR>";

    $private_key = openssl_pkey_get_private(readServerFile("./XeroCerts/privatekey.pem"));
    $public_key = openssl_pkey_get_public(readServerFile("./XeroCerts/publickey.cer"));

    //Block size for encryption block cipher for 1024 bit key
    $encrypt_size = 110;

    //Block size for decryption block cipher for 1024 bit key
    $decrypt_size = 128;

    //For encryption we would use:
    $encrypted = '';
    $data = str_split($data, $encrypt_size);
    foreach ($data as $chunk) {
        openssl_public_encrypt($chunk, $partial, $public_key, OPENSSL_PKCS1_PADDING);
        $encrypted .= $partial;
    }
    openssl_free_key($public_key);
    $encrypted = base64_encode($encrypted);
    echo "Encrypted=" . $encrypted . "<BR>";

    //For decryption we would use:
    $decrypted = '';
    $data = str_split(base64_decode($encrypted), $decrypt_size);
    foreach ($data as $chunk) {
        openssl_private_decrypt($chunk, $partial, $private_key, OPENSSL_PKCS1_PADDING);
        $decrypted .= $partial;
    }
    openssl_free_key($private_key);
    echo "Decrypted=" . $decrypted;
    die();
}

Output of the above code snippet is below:

If you don't want to save strings in clear text, there are new php functions (php >= 5.3.0) that can be of help; openssl_encrypt() and openssl_decrypt().

Original data length=5056
Encrypted=Vf2GHkx..............LgpFjM9gY/FkIYWaELHl3I=
Decrypted=Large data to test. ............ Large data to test. Large data to test. Large data to test.

Simple PHP encrypt and decrypt Using AES-256-CBC Algorithm | OpenSSL Encrypt | OpenSSL Decrypt

If you don't want to save strings in clear text, there are new php functions (php >= 5.3.0) that can be of help; openssl_encrypt() and openssl_decrypt().

<?php
define("SSL_SECRET_KEY", "SSL_SECRET_KEY");
define("SSL_SECRET_IV", "SSL_SECRET_IV");
define("SSL_ENCRYPTION_METHOD", "AES-256-CBC");
define("SSL_SECRET_IV_SIZE", openssl_cipher_iv_length(SSL_ENCRYPTION_METHOD));

function encryptData($string)
{
    $key = hash('sha256', SSL_SECRET_KEY);
    /* If you want random IV */
    //$iv = openssl_random_pseudo_bytes(SSL_SECRET_IV_SIZE);
    $iv = substr(hash('sha256', SSL_SECRET_IV), 0, SSL_SECRET_IV_SIZE);

    $output = openssl_encrypt($string, SSL_ENCRYPTION_METHOD, $key, 0, $iv);
    return base64_encode($output);
}

function decryptData($string)
{
    $key = hash('sha256', SSL_SECRET_KEY);
    $iv = substr(hash('sha256', SSL_SECRET_IV), 0, SSL_SECRET_IV_SIZE);

    return openssl_decrypt(base64_decode($string), SSL_ENCRYPTION_METHOD, $key, 0, $iv);
}

$REQUEST_URI = isset($_SERVER["REQUEST_URI"]) ? $_SERVER["REQUEST_URI"] : "";

if (strpos($REQUEST_URI, "enc.php") !== false) {
    $plain_txt = "Value to be encrypt & decrypt";
    echo "Original Text = $plain_txt<br/>";

    $encrypted_txt = encryptData($plain_txt);
    echo "Encrypted Text = $encrypted_txt<br/>";

    $decrypted_txt = decryptData($encrypted_txt);
    echo "Decrypted Text = $decrypted_txt<br/>";

    if ($plain_txt === $decrypted_txt) echo "SUCCESS";
    else echo "FAILED";

    echo "<br/>";
}

Original Text:
Value to be encrypt & decrypt

Encrypted Text =
RjFhMElpR0VzMVlPeVdtREVraFJzYnhnNXZ4ck4vSmhRVUtXWXJoUzBVWT0=

Decrypted Text
Value to be encrypt & decrypt

SUCCESS

Or (This will carry IV with encrypted text itself):

<?php
define("SSL_SECRET_KEY", "xorxorxorxorxor");
define("SSL_ENCRYPTION_METHOD", "AES-256-CBC");
define("SSL_SECRET_IV_SIZE", openssl_cipher_iv_length(SSL_ENCRYPTION_METHOD));

function encryptData($string)
{
    $key = hash('sha256', SSL_SECRET_KEY);
    $iv = openssl_random_pseudo_bytes(SSL_SECRET_IV_SIZE);

    $output = openssl_encrypt($string, SSL_ENCRYPTION_METHOD, $key, 0, $iv);
    return base64_encode($iv . ":" . $output);
}

function decryptData($string)
{
    $string = explode(":", base64_decode($string));
    $key = hash('sha256', SSL_SECRET_KEY);

    return openssl_decrypt($string[1], SSL_ENCRYPTION_METHOD, $key, 0, $string[0]);
}

$plain_txt = "Value to be encrypt & decrypt";
echo "Original Text = $plain_txt<br/>";

$encrypted_txt = encryptData($plain_txt);
echo "Encrypted Text = $encrypted_txt<br/>";

$decrypted_txt = decryptData($encrypted_txt);
echo "Decrypted Text = $decrypted_txt<br/>";

if ($plain_txt === $decrypted_txt) echo "SUCCESS";
else echo "FAILED";

echo "<br/>";

Original Text:
Value to be encrypt & decrypt

Encrypted Text:
NfDWpobv5RGaC29EpXvP7Dp2WkJjN2pETmdPendsZkdsMnBVQXBTK2pRekJTNkhlTndEdTRGd3h6eHpFPQ==

Decrypted Text:
Value to be encrypt & decrypt

SUCCESS

Get last word from URL after a slash in PHP (www.xxx.com/about.php/THIS_WORD)

This summary is not available. Please click here to view the post.

PHP - Sign Request Data With OpenSSL Private Key Pair

Below is a PHP code snippet to sign request data with OpenSSL private key. It's used to handshake with server to communicate with the server.

function signRequestParams($options)
{
    $private_key = openssl_pkey_get_private(readServerFile("./XeroCerts/privatekey.pem"));
    $sbs = escapeUrlEntity(normalizeParameters($options));
    openssl_sign($sbs, $signature, $private_key);
    openssl_free_key($private_key);
    return base64_encode($signature);
}

function readServerFile($file_path)
{
    $fp = fopen($file_path, "r");
    $file_contents = fread($fp, 8192);
    fclose($fp);
    return $file_contents;
}

function normalizeParameters($parameters)
{
    $elements = array();
    ksort($parameters);
    foreach ($parameters as $paramName => $paramValue) {
        /* If name contains "be_ignored" will be ignored */
        if (preg_match('/be_ignored/', $paramName))
            continue;
        if (is_array($paramValue)) {
            sort($paramValue);
            foreach ($paramValue as $element)
                array_push($elements, escapeUrlEntity($paramName) . '=' . escapeUrlEntity($element));
            continue;
        }
        array_push($elements, escapeUrlEntity($paramName) . '=' . escapeUrlEntity($paramValue));
    }
    return join('&', $elements);
}

function escapeUrlEntity($string)
{
    if ($string === 0)
        return 0;
    if (empty($string))
        return '';
    if (is_array($string))
        throw new Exception('Array passed to escapeUrlEntity');

    $string = rawurlencode($string);
    $string = str_replace('+', '%20', $string);
    $string = str_replace('!', '%21', $string);
    $string = str_replace('*', '%2A', $string);
    $string = str_replace('\'', '%27', $string);
    $string = str_replace('(', '%28', $string);
    $string = str_replace(')', '%29', $string);
    return $string;
}

$options = array(
    "card.PAN" => "4564710000000004",
    "card.CVN" => "847",
    "card.expiryMonth" => "12",
    "card.expiryYear" => "20"
);

$signature = signRequestParams($options);
echo "Signature=$signature";

Output will be as below:

Signature=UC/uRPTaNxMV02a9I/KlWL/BA8..............6Fx1hjEYHWXN0U=

How to sign string as well sign request body with public key using Java

Below is a code snippet which will sign your request using Public key.

package com.pkm.src;

import Base64OutputStream;
import IOUtil;

import javax.crypto.Cipher;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.security.MessageDigest;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

/**
 * Created by pritom on 24/05/2017.
 */
public class SignatureSigner {
    public static void main(String[] args) throws Exception {
        String certificateFile = ".....\\publickey.cer";
        String requestBody = "Param1=Value_Of_Param1&Param2=Value_Of_param2";
        String signature = encodeRSASHA1(certificateFile, requestBody);
        System.out.println("Signature=" + signature);
    }

    protected static String encodeRSASHA1(String certificateFile, String requestBody) throws Exception {
        FileInputStream certIn1 = new FileInputStream(certificateFile);
        CertificateFactory e = CertificateFactory.getInstance("X509");
        X509Certificate myCertificate = (X509Certificate) e.generateCertificate(certIn1);

        MessageDigest hashGen = MessageDigest.getInstance("SHA1");
        byte[] hash = hashGen.digest(requestBody.getBytes("UTF-8"));
        Cipher rsa = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        rsa.init(1, myCertificate);
        byte[] signature = rsa.doFinal(hash);

        ByteArrayInputStream sigIn = new ByteArrayInputStream(signature);
        ByteArrayOutputStream sigOut = new ByteArrayOutputStream();
        Base64OutputStream base64Out = new Base64OutputStream(sigOut, "");
        IOUtil.copy(sigIn, base64Out);
        base64Out.close();
        return new String(sigOut.toByteArray(), "US-ASCII");
    }
}

Which will output as below:

Signature=7GNccit4cY+rs4t/S0WBv.........+w1rYdiEO8PxuR3SQ=

Pages

Sunday, May 28, 2017

HI, Time = 28/05/2017 02:56 PM

Test variable value in array #Method 1

HI, Time = 28/05/2017 02:56 PM

Test variable value in array #Method 2

Saturday, May 27, 2017

Friday, May 26, 2017

Thursday, May 25, 2017

Wednesday, May 24, 2017