Online SHA1 Hash Generator

I'm making a php login, and I'm trying to decide whether to use SHA1 or Md5, or SHA256 which I read about in another stackoverflow article. Are any of them more secure than others? For SHA1/256, do I still use a salt?

Also, is this a secure way to store the password as a hash in mysql?

function createSalt(){    $string = md5(uniqid(rand(), true));    return substr($string, 0, 3);}$salt = createSalt();$hash = sha1($salt . $hash);

Just wonder if it's possible to generate a unique hash of every checkout-webpage that is live on a webserver. In terminal i can create a SHA-1 key by using the command:

curl www.mysuperduerwebdomain.com/index.php | openssl sha1 -binary | base64

that generates:

% Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed100 13134 100 13134 0 0 222k 0 --:--:-- --:--:-- --:--:-- 225k

40Sw9Z/0COwZhLoVPesahtaib0E=

If i put this generated hash into a myslq table, and it's compared every time the webpage loads to the generated SHA-1 key at that moment, and both are the same, the content of the loaded checkout page is the same. (and no malicious javascript code was embedded for instance.) Have i got the theory right?

I have done a script in Python which is:

hashed_string = hashlib.sha1(str(string_to_hash).encode('utf-8')).hexdigest()

and it works as I want, but I can't figure out how to do it in JavaScript.I have done this in JS:

const crypto = require('crypto') let shasum = crypto.createHash('sha1') let hashed_string = shasum.update(JSON.stringify(string_to_hash).digest('hex'))

But the result is not the same. Can anyone help me please?

Below i had encrypted a string varible using sha1. And now i would wish to decrypt data using sha1 function, but am going some where. Would some one come forward and guide me in proper way please.

Below is my code

<?php   $variable  = "tiger";   echo $variable;   $encrypt = sha1($variable);   echo $encrypt;   $decrypt = sha1($encrypt);   echo $decrypt; ?>

And i get output like this

tiger46e3d772a1888eadff26c7ada47fd7502d796e07989df2c8b5ea37eb7cfde0527d94c01a15257002

I'm storing the user password on the db as a sha1 hash.

Unfortunately I'm getting strange answers.

I'm storing the string as this:

MessageDigest cript = MessageDigest.getInstance("SHA-1");              cript.reset();              cript.update(userPass.getBytes("utf8"));              this.password = new String(cript.digest());

I wanted something like this -->

aff --> "0c05aa56405c447e6678b7f3127febde5c3a9238"

rather than

aff --> �V@\D~fx����:�8