MD5 Hash Online Generador

When I go to Localhost and try the username and the password it tells me that is an error? why?

my codes:

<?phpsession_start();if (isset($_SESSION["user_id"])) {    header("location: /web/home.php");}if (isset($_POST["s"])) {    $username = $_POST["un"];    $password = $_POST["ps"];    $enc_password = md5($password);    $con = mysqli_connect("localhost", "root", "", "my_db");    $query = "select * from my_db where     username = '" . $username . "'     and     password = '" . $enc_password . "'";    $rs = mysqli_query($con,$query);    if(mysqli_num_rows($rs) > 0){        $record = mysqli_fetch_assoc($rs);        $_SESSION["user_id"]= $record["user_id"];        header("location: /web/home.php");    } else {        echo "<h3 style = 'color:red'>Error in username or password</h3>";    }}?>

When I go to Localhost and try the username and the password it tells me that is an error? why?

I'm developing a local file encryption/decryption software (AES-256 CBC),which I want to validate decryption was successful or not.

so I decided to add an additional MD5 hash of plain data to end of plain data and encrypt it together,and when decryption, calculate the MD5 hash of decryption data(except last additional MD5 hash) andcompare it with last additional MD5 hash.

I want to know if this idea is safe to use.

Is it a bad idea?

I read some docs about md5, it said that its 128 bits, but why is it 32 characters? I can't compute the characters.

• 1 byte is 8 bits
• if 1 character is 1 byte
• then 128 bits is 128/8 = 16 bytes right?

EDIT:

SHA-1 produces 160 bits, so how many characters are there?

I need to calculate the CRC32, MD5 and SHA1 of the content of zip files without decompressing them.

So far I found out how to calculate these for the zip files itself, e.g.:

CRC32:

import zlibzip_name = "test.zip"def Crc32Hasher(file_path):    buf_size = 65536    crc32 = 0    with open(file_path, 'rb') as f:        while True:            data = f.read(buf_size)            if not data:                break            crc32 = zlib.crc32(data, crc32)    return format(crc32 & 0xFFFFFFFF, '08x')print(Crc32Hasher(zip_name))

SHA1: (MD5 similarly)

import hashlibzip_name = "test.zip"def Sha1Hasher(file_path):    buf_size = 65536    sha1 = hashlib.sha1()    with open(file_path, 'rb') as f:        while True:            data = f.read(buf_size)            if not data:                break            sha1.update(data)    return format(sha1.hexdigest())print(Sha1Hasher(zip_name))

For the content of the zip file, I can read the CRC32 from the zip directly without the need of calculating it as follow:

Read CRC32 of zip content:

import zipfilezip_name = "test.zip"if zip_name.lower().endswith(('.zip')):    z = zipfile.ZipFile(zip_name, "r")for info in z.infolist():    print(info.filename,          format(info.CRC & 0xFFFFFFFF, '08x'))

But I couldn't figure out how to calculate the SHA1 (or MD5) of the content of zip files without decompressing them first.Is that somehow possible?

Is there a way to calculate the MD5 hash of a file before the upload to the server using Javascript?