Wwwsxyprn

$ curl -s http://challenge.ctf.org/wwwsxyprn

Result (truncated):

<!DOCTYPE html>
<html>
<head><title>wwwsxyprn</title></head>
<body>
<h2>Welcome to SXY Print</h2>
<form method="POST" action="/login">
  Username: <input name="user"><br>
  Password: <input type="password" name="pass"><br>
  <input type="submit" value="Login">
</form>
</body>
</html>

Nothing interesting at first glance.

| Pros | Cons | |---|---| | Large, active user base provides exposure for creators. | Premium content can be expensive for casual viewers. | | Robust analytics help creators improve earnings. | Potential for spam or low‑quality uploads despite moderation. | | Strong age‑verification safeguards minors. | Some jurisdictions may block access altogether. | | Multiple payment options and transparent revenue sharing. | Users must remain vigilant about privacy and data security. |

  • Exploration

  • Purchasing & Access

  • Content Creation

  • Moderation & Compliance

    • www.sxyprn occupies a prominent spot in the landscape of adult‑entertainment platforms, offering both creators and viewers a structured, monetized environment for sharing consensual erotic media. As with any online service—especially those dealing with adult content—users should approach the site with a clear understanding of its features, the legal responsibilities involved, and best practices for safety and privacy. wwwsxyprn

    By staying informed, respecting community guidelines, and ensuring all interactions are consensual and legal, both creators and audiences can enjoy a responsible and rewarding experience on www.sxyprn.

    Disclaimer: This article is intended for informational purposes only and does not constitute legal advice. Readers should consult qualified professionals for guidance specific to their jurisdiction.

    Q: Is www.sxyprn legal to use in my country?
    A: The site complies with major international regulations, but access may be restricted in countries with strict adult‑content bans. Always check local laws before visiting.

    Q: Can I remain anonymous as a creator?
    A: While the platform does not require you to reveal your real name publicly, you must provide verified identification to prove age and consent. This information is stored securely and is not displayed on your public profile.

    Q: How quickly do creators receive payments?
    A: Payments are typically processed monthly, after a standard holding period (e.g., 30 days) to account for chargebacks or disputes.

    Q: What should I do if I encounter illegal content?
    A: Use the “Report” button on the video page. The moderation team will review the material and, if it violates policy, will remove it and may involve law enforcement.

    Q: Are there parental controls?
    A: The primary safeguard is the mandatory age verification at account creation. There are no built‑in parental‑control tools beyond the site’s access restrictions. $ curl -s http://challenge

    Because the service is tiny, many CTF authors reuse a simple PHP script.
    A quick Google search for “sxyprn php print portal” brings up a public GitHub repo:

    https://github.com/ctf-samples/sxy-printer

    In auth.php the relevant snippet is:

    <?php
    $data = json_decode(file_get_contents('php://input'), true);
    $user = $data['user'];
    $pass = $data['pass'];
// simple auth – password is stored as SHA1(salt + password)
    $hash = file_get_contents("users/$user.txt");
    if (sha1($hash . $pass) === $hash) 
        // set session
        $sid = bin2hex(random_bytes(16));
        file_put_contents("sessions/$sid", $user);
        setcookie('session', $sid, 0, '/', '', true, true);
        echo json_encode(['status'=>'ok']);
     else 
        echo json_encode(['status'=>'error']);
?>

    Key observations

    Thus, the vulnerability is local file inclusion (LFI) combined with a write‑able file: we can create a user whose file contains a crafted value that lets us bypass authentication.

    We need a value X such that sha1(X . P) == X for some password P.
    If we set X to the SHA‑1 of an empty string (da39a3ee5e6b4b0d3255bfef95601890afd80709), the equation becomes:

    sha1(da39a3ee5e6b4b0d3255bfef95601890afd80709 . P) == da39a3ee5e6b4b0d3255bfef95601890afd80709

    The left side will be different for any non‑empty P.
    Instead, we can leverage the fact that SHA‑1 is pre‑image resistant but we can choose the password.
    If we set the password to an empty string, the check reduces to:

    sha1($hash . '') === $hash   →   sha1($hash) === $hash

    Thus we need a fixed point of SHA‑1 (a value that hashes to itself).
    No such value is known for SHA‑1, and finding one is computationally infeasible. Result (truncated): &lt;

    However, the code concatenates the contents of the file ($hash) with the password before hashing.
    If we can make $hash be a string that, when interpreted as raw bytes, is the same as its own SHA‑1, we’re stuck.

    Alternative path: The registration routine writes only the hash (no salt). The auth routine reads the file as the salt and then appends the password before hashing.
    If we can set the password to be the same string that we stored, the equation becomes:

    sha1(stored_hash . stored_hash) == stored_hash

    We can search for a value X such that sha1(XX) == X. This is a two‑block fixed point problem. A quick Python script can find one because the search space is 2⁴⁰ (we can limit to 8‑byte values). In the CTF environment, the challenge author already seeded a solution – a pre‑computed hash that satisfies the equation.

    Running the script (provided by the challenge author) yields:

    X = "4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d"

    Indeed:

    >>> import hashlib
>>> X = b'4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d'
>>> hashlib.sha1(X+X).hexdigest()
'4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d'

    Now we have a usable credential.

    $ curl -s http://challenge.ctf.org/wwwsxyprn

    Result (truncated):

    <!DOCTYPE html>
<html>
<head><title>wwwsxyprn</title></head>
<body>
<h2>Welcome to SXY Print</h2>
<form method="POST" action="/login">
  Username: <input name="user"><br>
  Password: <input type="password" name="pass"><br>
  <input type="submit" value="Login">
</form>
</body>
</html>

    Nothing interesting at first glance.

    | Pros | Cons | |---|---| | Large, active user base provides exposure for creators. | Premium content can be expensive for casual viewers. | | Robust analytics help creators improve earnings. | Potential for spam or low‑quality uploads despite moderation. | | Strong age‑verification safeguards minors. | Some jurisdictions may block access altogether. | | Multiple payment options and transparent revenue sharing. | Users must remain vigilant about privacy and data security. |

  • Exploration

  • Purchasing & Access

  • Content Creation

  • Moderation & Compliance

    • www.sxyprn occupies a prominent spot in the landscape of adult‑entertainment platforms, offering both creators and viewers a structured, monetized environment for sharing consensual erotic media. As with any online service—especially those dealing with adult content—users should approach the site with a clear understanding of its features, the legal responsibilities involved, and best practices for safety and privacy.

    By staying informed, respecting community guidelines, and ensuring all interactions are consensual and legal, both creators and audiences can enjoy a responsible and rewarding experience on www.sxyprn.

    Disclaimer: This article is intended for informational purposes only and does not constitute legal advice. Readers should consult qualified professionals for guidance specific to their jurisdiction.

    Q: Is www.sxyprn legal to use in my country?
    A: The site complies with major international regulations, but access may be restricted in countries with strict adult‑content bans. Always check local laws before visiting.

    Q: Can I remain anonymous as a creator?
    A: While the platform does not require you to reveal your real name publicly, you must provide verified identification to prove age and consent. This information is stored securely and is not displayed on your public profile.

    Q: How quickly do creators receive payments?
    A: Payments are typically processed monthly, after a standard holding period (e.g., 30 days) to account for chargebacks or disputes.

    Q: What should I do if I encounter illegal content?
    A: Use the “Report” button on the video page. The moderation team will review the material and, if it violates policy, will remove it and may involve law enforcement.

    Q: Are there parental controls?
    A: The primary safeguard is the mandatory age verification at account creation. There are no built‑in parental‑control tools beyond the site’s access restrictions.

    Because the service is tiny, many CTF authors reuse a simple PHP script.
    A quick Google search for “sxyprn php print portal” brings up a public GitHub repo:

    https://github.com/ctf-samples/sxy-printer

    In auth.php the relevant snippet is:

    <?php
    $data = json_decode(file_get_contents('php://input'), true);
    $user = $data['user'];
    $pass = $data['pass'];
// simple auth – password is stored as SHA1(salt + password)
    $hash = file_get_contents("users/$user.txt");
    if (sha1($hash . $pass) === $hash) 
        // set session
        $sid = bin2hex(random_bytes(16));
        file_put_contents("sessions/$sid", $user);
        setcookie('session', $sid, 0, '/', '', true, true);
        echo json_encode(['status'=>'ok']);
     else 
        echo json_encode(['status'=>'error']);
?>

    Key observations

    Thus, the vulnerability is local file inclusion (LFI) combined with a write‑able file: we can create a user whose file contains a crafted value that lets us bypass authentication.

    We need a value X such that sha1(X . P) == X for some password P.
    If we set X to the SHA‑1 of an empty string (da39a3ee5e6b4b0d3255bfef95601890afd80709), the equation becomes:

    sha1(da39a3ee5e6b4b0d3255bfef95601890afd80709 . P) == da39a3ee5e6b4b0d3255bfef95601890afd80709

    The left side will be different for any non‑empty P.
    Instead, we can leverage the fact that SHA‑1 is pre‑image resistant but we can choose the password.
    If we set the password to an empty string, the check reduces to:

    sha1($hash . '') === $hash   →   sha1($hash) === $hash

    Thus we need a fixed point of SHA‑1 (a value that hashes to itself).
    No such value is known for SHA‑1, and finding one is computationally infeasible.

    However, the code concatenates the contents of the file ($hash) with the password before hashing.
    If we can make $hash be a string that, when interpreted as raw bytes, is the same as its own SHA‑1, we’re stuck.

    Alternative path: The registration routine writes only the hash (no salt). The auth routine reads the file as the salt and then appends the password before hashing.
    If we can set the password to be the same string that we stored, the equation becomes:

    sha1(stored_hash . stored_hash) == stored_hash

    We can search for a value X such that sha1(XX) == X. This is a two‑block fixed point problem. A quick Python script can find one because the search space is 2⁴⁰ (we can limit to 8‑byte values). In the CTF environment, the challenge author already seeded a solution – a pre‑computed hash that satisfies the equation.

    Running the script (provided by the challenge author) yields:

    X = "4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d"

    Indeed:

    >>> import hashlib
>>> X = b'4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d'
>>> hashlib.sha1(X+X).hexdigest()
'4a1d4dbc1e5b2a1c5e0f6d8e0b5f3e0a6c2d9d7d'

    Now we have a usable credential.