http curl - How do I send a POST request with PHP?




json data (10)

Try PEAR's HTTP_Request2 package to easily send POST requests. Alternatively, you can use PHP's curl functions or use a PHP stream context.

HTTP_Request2 also makes it possible to mock out the server, so you can unit-test your code easily

Actually I want to read the contents that come after the search query, when it is done. The problem is that the URL only accepts POST methods, and it does not take any action with GET method...

I have to read all contents with the help of domdocument or file_get_contents(). Is there any method that will let me send parameters with POST method and then read the contents via PHP?


CURL-less method with PHP5:

$url = 'http://server.com/path';
$data = array('key1' => 'value1', 'key2' => 'value2');

// use key 'http' even if you send the request to https://...
$options = array(
    'http' => array(
        'header'  => "Content-type: application/x-www-form-urlencoded\r\n",
        'method'  => 'POST',
        'content' => http_build_query($data)
    )
);
$context  = stream_context_create($options);
$result = file_get_contents($url, false, $context);
if ($result === FALSE) { /* Handle error */ }

var_dump($result);

See the PHP manual for more information on the method and how to add headers, for example:


I'd like to add some thoughts about the curl-based answer of Fred Tanrikut. I know most of them are already written in the answers above, but I think it is a good idea to show an answer that includes all of them together.

Here is the class I wrote to make HTTP-GET/POST/PUT/DELETE requests based on curl, concerning just about the response body:

class HTTPRequester {
    /**
     * @description Make HTTP-GET call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPGet($url, array $params) {
        $query = http_build_query($params); 
        $ch    = curl_init($url.'?'.$query);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, false);
        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }
    /**
     * @description Make HTTP-POST call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPPost($url, array $params) {
        $query = http_build_query($params);
        $ch    = curl_init();
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_HEADER, false);
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $query);
        $response = curl_exec($ch);
        curl_close($ch);
        return $response;
    }
    /**
     * @description Make HTTP-PUT call
     * @param       $url
     * @param       array $params
     * @return      HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPPut($url, array $params) {
        $query = \http_build_query($params);
        $ch    = \curl_init();
        \curl_setopt($ch, \CURLOPT_RETURNTRANSFER, true);
        \curl_setopt($ch, \CURLOPT_HEADER, false);
        \curl_setopt($ch, \CURLOPT_URL, $url);
        \curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'PUT');
        \curl_setopt($ch, \CURLOPT_POSTFIELDS, $query);
        $response = \curl_exec($ch);
        \curl_close($ch);
        return $response;
    }
    /**
     * @category Make HTTP-DELETE call
     * @param    $url
     * @param    array $params
     * @return   HTTP-Response body or an empty string if the request fails or is empty
     */
    public static function HTTPDelete($url, array $params) {
        $query = \http_build_query($params);
        $ch    = \curl_init();
        \curl_setopt($ch, \CURLOPT_RETURNTRANSFER, true);
        \curl_setopt($ch, \CURLOPT_HEADER, false);
        \curl_setopt($ch, \CURLOPT_URL, $url);
        \curl_setopt($ch, \CURLOPT_CUSTOMREQUEST, 'DELETE');
        \curl_setopt($ch, \CURLOPT_POSTFIELDS, $query);
        $response = \curl_exec($ch);
        \curl_close($ch);
        return $response;
    }
}

Improvements

  • Using http_build_query to get the query-string out of an request-array.(you could also use the array itself, therefore see: http://php.net/manual/en/function.curl-setopt.php)
  • Returning the response instead of echoing it. Btw you can avoid the returning by removing the line curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);. After that the return value is a boolean(true = request was successful otherwise an error occured) and the response is echoed. See: http://php.net/en/manual/function.curl-exec.php
  • Clean session closing and deletion of the curl-handler by using curl_close. See: http://php.net/manual/en/function.curl-close.php
  • Using boolean values for the curl_setopt function instead of using any number.(I know that any number not equal zero is also considered as true, but the usage of true generates a more readable code, but that's just my opinion)
  • Ability to make HTTP-PUT/DELETE calls(useful for RESTful service testing)

Example of usage

GET

$response = HTTPRequester::HTTPGet("http://localhost/service/foobar.php", array("getParam" => "foobar"));

POST

$response = HTTPRequester::HTTPPost("http://localhost/service/foobar.php", array("postParam" => "foobar"));

PUT

$response = HTTPRequester::HTTPPut("http://localhost/service/foobar.php", array("putParam" => "foobar"));

DELETE

$response = HTTPRequester::HTTPDelete("http://localhost/service/foobar.php", array("deleteParam" => "foobar"));

Testing

You can also make some cool service tests by using this simple class.

class HTTPRequesterCase extends TestCase {
    /**
     * @description test static method HTTPGet
     */
    public function testHTTPGet() {
        $requestArr = array("getLicenses" => 1);
        $url        = "http://localhost/project/req/licenseService.php";
        $this->assertEquals(HTTPRequester::HTTPGet($url, $requestArr), '[{"error":false,"val":["NONE","AGPL","GPLv3"]}]');
    }
    /**
     * @description test static method HTTPPost
     */
    public function testHTTPPost() {
        $requestArr = array("addPerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPPost($url, $requestArr), '[{"error":false}]');
    }
    /**
     * @description test static method HTTPPut
     */
    public function testHTTPPut() {
        $requestArr = array("updatePerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPPut($url, $requestArr), '[{"error":false}]');
    }
    /**
     * @description test static method HTTPDelete
     */
    public function testHTTPDelete() {
        $requestArr = array("deletePerson" => array("foo", "bar"));
        $url        = "http://localhost/project/req/personService.php";
        $this->assertEquals(HTTPRequester::HTTPDelete($url, $requestArr), '[{"error":false}]');
    }
}

Another alternative of the curl-less method above is to use the native stream functions:

  • stream_context_create():

    Creates and returns a stream context with any options supplied in options preset.

  • stream_get_contents():

    Identical to file_get_contents(), except that stream_get_contents() operates on an already open stream resource and returns the remaining contents in a string, up to maxlength bytes and starting at the specified offset.

A POST function with these can simply be like this:

<?php

function post_request($url, array $params) {
  $query_content = http_build_query($params);
  $fp = fopen($url, 'r', FALSE, // do not use_include_path
    stream_context_create([
    'http' => [
      'header'  => [ // header array does not need '\r\n'
        'Content-type: application/x-www-form-urlencoded',
        'Content-Length: ' . strlen($query_content)
      ],
      'method'  => 'POST',
      'content' => $query_content
    ]
  ]));
  if ($fp === FALSE) {
    fclose($fp);
    return json_encode(['error' => 'Failed to get contents...']);
  }
  $result = stream_get_contents($fp); // no maxlength/offset
  fclose($fp);
  return $result;
}

I was looking for a similar problem and found a better approach of doing this. So here it goes.

You can simply put the following line on the redirection page (say page1.php).

header("Location: URL", TRUE, 307); // Replace URL with to be redirected URL, e.g. final.php

I need this to redirect POST requests for REST API calls. This solution is able to redirect with post data as well as custom header values.

Here is the reference link.


There is one more which you can use

<?php
$fields = array(
    'name' => 'mike',
    'pass' => 'se_ret'
);
$files = array(
    array(
        'name' => 'uimg',
        'type' => 'image/jpeg',
        'file' => './profile.jpg',
    )
);

$response = http_post_fields("http://www.example.com/", $fields, $files);
?>

Click here for details


You could use cURL:

<?php
//The url you wish to send the POST request to
$url = $file_name;

//The data you want to send via POST
$fields = [
    '__VIEWSTATE '      => $state,
    '__EVENTVALIDATION' => $valid,
    'btnSubmit'         => 'Submit'
];

//url-ify the data for the POST
$fields_string = http_build_query($fields);

//open connection
$ch = curl_init();

//set the url, number of POST vars, POST data
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_POST, count($fields));
curl_setopt($ch,CURLOPT_POSTFIELDS, $fields_string);

//So that curl_exec returns the contents of the cURL; rather than echoing it
curl_setopt($ch,CURLOPT_RETURNTRANSFER, true); 

//execute post
$result = curl_exec($ch);
echo $result;
?>

I recommend you to use the open-source package guzzle that is fully unit tested and uses the latest coding practices.

Installing Guzzle

Go to the command line in your project folder and type in the following command (assuming you already have the package manager composer installed). If you need help how to install Composer, you should have a look here.

php composer.phar require guzzlehttp/guzzle

Using Guzzle to send a POST request

The usage of Guzzle is very straight forward as it uses a light-weight object-oriented API:

// Initialize Guzzle client
$client = new GuzzleHttp\Client();

// Create a POST request
$response = $client->request(
    'POST',
    'http://example.org/',
    [
        'form_params' => [
            'key1' => 'value1',
            'key2' => 'value2'
        ]
    ]
);

// Parse the response object, e.g. read the headers, body, etc.
$headers = $response->getHeaders();
$body = $response->getBody();

// Output headers and body for debugging purposes
var_dump($headers, $body);

If you by any chance are using Wordpress to develop your app (it's actually a convenient way to get authorization, info pages etc even for very simple stuff), you can use the following snippet:

$response = wp_remote_post( $url, array('body' => $parameters));

if ( is_wp_error( $response ) ) {
    // $response->get_error_message()
} else {
    // $response['body']
}

It uses different ways of making the actual HTTP request, depending on what is available on the web server. For more details, see the HTTP API documentation.

If you don't want to develop a custom theme or plugin to start the Wordpress engine, you can just do the following in an isolated PHP file in the wordpress root:

require_once( dirname(__FILE__) . '/wp-load.php' );

// ... your code

It won't show any theme or output any HTML, just hack away with the Wordpress APIs!


Regarding many useful answers, I hope to add some values to this thread. SQL injection is an attack that can be done through user inputs (Inputs that filled by user and then used inside queries), The SQL injection patterns are correct query syntax while we can call it: bad queries for bad reasons, we assume that there might be bad person that try to get secret information (bypassing access control) that affect the three principles of security (Confidentiality, Integrity, Availability).

Now, our point is to prevent security threats such as SQL injection attacks, the question asking (How to prevent SQL injection attack using PHP), be more realistic, data filtering or clearing input data is the case when using user-input data inside such query, using PHP or any other programming language is not the case, or as recommended by more people to use modern technology such as prepared statement or any other tools that currently supporting SQL injection prevention, consider that these tools not available anymore? How you secure your application?

My approach against SQL injection is: clearing user-input data before sending it to the database (before using it inside any query).

Data filtering for (Converting unsafe data to safe data) Consider that PDO and MySQLi not available, how can you secure your application? Do you force me to use them? What about other languages other than PHP? I prefer to provide general ideas as it can be used for wider border not just for specific language.

  1. SQL user (limiting user privilege): most common SQL operations are (SELECT, UPDATE, INSERT), then, why giving UPDATE privilege to a user that not require it? For example login, and search pages are only using SELECT, then, why using DB users in these pages with high privileges? RULE: do not create one database user for all privileges, for all SQL operations, you can create your scheme like (deluser, selectuser, updateuser) as usernames for easy usage.

see Principle of least privilege

  1. Data filtering: before building any query user input should be validated and filtered, for programmers, it's important to define some properties for each user-input variables: data type, data pattern, and data length. a field that is a number between (x and y) must be exactly validated using exact rule, for a field that is a string (text): pattern is the case, for example, username must contain only some characters lets say [a-zA-Z0-9_-.] the length varies between (x and n) where x and n (integers, x <=n ). Rule: creating exact filters and validation rules are best practice for me.

  2. Use other tools: Here, I will also agree with you that prepared statement (parametrized query) and Stored procedures, the disadvantages here is these ways requires advanced skills which do not exist for most users, the basic idea here is to distinguish between SQL query and the data that being used inside, both approaches can be used even with unsafe data, because the user-input data here not add anything to the original query such as (any or x=x). For more information, please read OWASP SQL Injection Prevention Cheat Sheet.

Now, if you are an advanced user, start using this defense as you like, but, for beginners, if they can't quickly implement stored procedure and prepared the statement, it's better to filter input data as much they can.

Finally, let's consider that user sends this text below instead of entering his username:

[1] UNION SELECT IF(SUBSTRING(Password,1,1)='2',BENCHMARK(100000,SHA1(1)),0) User,Password FROM mysql.user WHERE User = 'root'

This input can be checked early without any prepared statement and stored procedures, but to be on safe side, using them starts after user-data filtering and validation.

The last point is detecting unexpected behavior which requires more effort and complexity; it's not recommended for normal web applications. Unexpected behavior in above user input is SELECT, UNION, IF, SUBSTRING, BENCHMARK, SHA, root once these words detected, you can avoid the input.

UPDATE1:

A user commented that this post is useless, OK! Here is what OWASP.ORG provided:

Primary defenses:

Option #1: Use of Prepared Statements (Parameterized Queries)
Option #2: Use of Stored Procedures
Option #3: Escaping all User Supplied Input

Additional defenses:

Also Enforce: Least Privilege
Also Perform: White List Input Validation

As you may know, claiming on an article should be supported by valid argument, at least one reference! Otherwise, it's considered as an attack and bad claim!

Update2:

From the PHP manual, PHP: Prepared Statements - Manual:

Escaping and SQL injection

Bound variables will be escaped automatically by the server. The server inserts their escaped values at the appropriate places into the statement template before execution. A hint must be provided to the server for the type of bound variable, to create an appropriate conversion. See the mysqli_stmt_bind_param() function for more information.

The automatic escaping of values within the server is sometimes considered a security feature to prevent SQL injection. The same degree of security can be achieved with non-prepared statements if input values are escaped correctly.

Update3:

I created test cases for knowing how PDO and MySQLi send the query to MySQL server when using prepared statement:

PDO:

$user = "''1''"; //Malicious keyword
$sql = 'SELECT * FROM awa_user WHERE userame =:username';
$sth = $dbh->prepare($sql, array(PDO::ATTR_CURSOR => PDO::CURSOR_FWDONLY));
$sth->execute(array(':username' => $user));

Query Log:

    189 Query SELECT * FROM awa_user WHERE userame ='\'\'1\'\''
    189 Quit

MySQLi:

$stmt = $mysqli->prepare("SELECT * FROM awa_user WHERE username =?")) {
$stmt->bind_param("s", $user);
$user = "''1''";
$stmt->execute();

Query Log:

    188 Prepare   SELECT * FROM awa_user WHERE username =?
    188 Execute   SELECT * FROM awa_user WHERE username ='\'\'1\'\''
    188 Quit

It's clear that a prepared statement is also escaping the data, nothing else.

As also mentioned in above statement The automatic escaping of values within the server is sometimes considered a security feature to prevent SQL injection. The same degree of security can be achieved with non-prepared statements, if input values are escaped correctly, therefore, this proves that data validation such as intval() is a good idea for integer values before sending any query, in addition, preventing malicious user data before sending the query is correct and valid approach.

Please see this question for more detail: PDO sends raw query to MySQL while Mysqli sends prepared query, both produce the same result

References:

  1. SQL Injection Cheat Sheet
  2. SQL Injection
  3. Information security
  4. Security Principles
  5. Data validation




php http post request