This question already has answers here:
Is it possible to decrypt MD5 hashes?
(24 answers)
Closed 3 years ago.
i am creating one admin panel for my app but the main problem is that when i am displaying password to admin in plain text then it will creates problem ??
i have stored my password in md5 format in php ? how can i able to decrypt that code in plain text in php ?
i have tried several times with every possibilities, but i haven's find any right answer yet now ?
$string ="hello";
$password= md5 ($string);
i expect plain text password which is reverse of encryption, that is decryption
In Theory no you can't. MD5 is ONE WAY hash algorithm. The original string is (lost) throught transformations. The sequrity of MD5 is compromised but you can not "decrypt or reverse" it. You can use a Rainbow Tables and try to find a match. Why you want to see User Password in clear text? The reason of hashing (encryption but without decryption key) is to protect privacy by turning personal information into “for your eyes only”, it's meens only User shoud be know the Password.
Md5 is a hash algorithm, sometimes incorrectly referred to as “one way encryption”. There is no way to get the original string back.
Also, why would you like to show the password in plain text? That can be a serious security issue. The purpose of hashing is to make sure the user writes the same password every time without anyone else knowing what the password is.
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This question already has answers here:
Is it possible to decrypt MD5 hashes?
(24 answers)
Closed 5 years ago.
Before knowing about just how dangerous md5 is, I have used it to store passwords. Md5 is terrible for security, and can easily be decoded. I now have 70,000 users registered in my database. Big mistake.
Now, since MD5 can be decoded into a string easily I was wondering if it is possible to loop through everyone's password in my MySQL database, decode it, and change it to a much stronger salt hashing system where it cannot be decoded to a string again. Would this be a viable option or even possible? Or is my only solution to do a hard database reset. Prompting users to change passwords would not be a good solution.
No. However, you can work around it, sort of:
Add a new field to your database to hold a second password.
Allow your users to log in as normal, with the MD5 system.
After they have successfully authenticated, you know their password. So now just use password_hash() on it and store it in the new field.
After some amount of time has passed, all active users will have their password encoded both ways.
Remove the MD5 authentication and replace it with password_verify().
Any users that hadn't logged in during the transition period will simply have to reset their password.
Keep the transition period as short as reasonably possible. This will allow your most active users to transition transparently without having to leave your system exposed for too long.
Note -- ultimately, you should have them change their passwords, as the current ones should be considered weak.
Edit for clarification:
You don't necessarily need to make a new password column. Since the hashes generated by password_hash() can be easily differentiated from those generated by md5(), you can simply use a strlen() check to determine which method to use. However, if you made your password field exactly the width of an MD5 hash string, then it's not going to be wide enough to hold the output of password_hash().
This question already has answers here:
Is it possible to decrypt MD5 hashes?
(24 answers)
Closed 6 years ago.
I have a hashed MD5 password saved in a MySQL database. Is there anyway to find out how many characters were in the original password?
I don't think there is because from what I've read it's difficult to decrypt a hashed password anyway.
Anyway I can do this?
EDIT: Because of the serious amount of backlash!! I'm not interested in decrypting a hash, because I know thats not a great idea from what I've read.
The reason I ask is because.
I am migrating an old system including historic database to a new updated application. All users, many thousands have their password saved in the database MD5, but most with less than 8 characters, so I just wanted to know if there was a way to know if their original password was over 8 characters, then I can bcrypt it or force users to change their password.
But I'll have to force all users to change their passwords by the looks of it
From OP's comment:
i was just purely asking to save forcing all users to ti change their passwords if their password was below a certain character limit – frobak
The answer to this then is to use strlen():
http://php.net/manual/en/function.strlen.php
As for MD5, don't use it it's totally unsafe. A lot of water has gone under the bridge in over 30 years.
Use password_hash():
http://php.net/manual/en/function.password-hash.php
As for decrypting a hash; it can't be done/reversed; that's why it's called a hash and not encrypted.
There are what's called "Rainbow tables":
https://en.wikipedia.org/wiki/Rainbow_table
But I'll have to force all users to change their passwords by the looks of it
Consult the following: Converting md5 password hashes to PHP 5.5 password_hash()
That way you can "hit two posts with one stone".
However, MD5 is 32-length. You will need to increase that to 60+ in order to have the proper length when using password_hash() and as Jay Blanchard stated in his comment, otherwise that may fail "silently" later on when using password_verify().
Nope. You can generate random strings and hash those until you find a match and measure the length of that (this will take an extremely long time, and may actually be incorrect because of collisions, don't do it), but outside of that, it's impossible.
The answer is already given and is worth upvoting, nevertheless I would like to share another view on the problem.
Is it possible to find out the character length?
No actually there is no way to tell the number of characters in the original password from a MD5 hash.
Is it possible to find the passwords with less than 8 characters?
Unfortunately yes. Since cracker tools can brute-force about 20 Giga Md5 per second it is possible to test all 7 character password combinations (a-z A-Z 0-9) in only 3 minutes!
Please note that this is not what I recommend to do, since it would be illegal, it is just to show how unsafe such hashes are. Instead you can calculate a second hash from the stored MD5 hash, I described this in another answer.
This question already has answers here:
Secure hash and salt for PHP passwords
(14 answers)
Closed 7 years ago.
i'm new to php password hashing since i'm also a beginner in php coding. I was able to make a simple login form, it requires a username and password. This password will then be saved to a database by Inserting into table using $_POST['password']. However i read that this is unsafe because its a plain text, you need to hash it.
I tried researching about password hashing in php. i found several write-ups but most of it are not clear for a beginner like me. Though i got some basic ideas but can't think on how to implement it.
Some of my questions:
1. How do I hash the password inputted by the user?
2. Once it is hashed, how do i pass it and save it to my database?
3. Is the password will then be saved as a hash (not plain text) in my database? if so, do i need to extend field length in my database to accommodate long hash passwords?
Those are some of my queries which is obviously from a beginner.
I hope someone would enlighten me or show me where to start. I prefer basics so that I can comprehend.
Thank you very much!
EDIT: ok found some answers on the link provided. Thanks for tagging it as duplicate and i'm sorry for that. cheers!!
The most basic is $var = md5($_POST['password']), you may want to use sha but I would recommend that you use SALT :)
For saving it to the database, it is also the same
"INSERT INTO 'tablename' WHERE password = '$var'"
note that md5 is easy to decrypt, this is only to show you how to hash your password.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
PHP 2-way encryption: I need to store passwords that can be retrieved
I am working with encrypt the password:
php> echo bin2hex(mhash(MHASH_SHA1,'test'));
a94a8fe5ccb19ba61c4c0873d391e987982fbbd3
My question is if I have a94a8fe5ccb19ba61c4c0873d391e987982fbbd3 How Can I get back the test.
Are the function to de-encrypt?
your have to understand the diff between a hash function an encryption.
Hashes are one way. You can't convert back. Checking passwords on login usually works by hashing the password from login, too and then just check if hashes are the same.
Using SHA1 it is easy to convert some text into a hash, but going the other way is very, very time consuming, which is one reason why it's good to use for encryption, and in your example passwords.
You may have some luck with this site -
http://www.md5decrypter.co.uk/sha1-decrypt.aspx
It has a list of common hashes and your example 'test' was easily found.
Why do you want to decode the hash output? You can check the password by hash, instead of trying to decode it. By the way, you can't decode a hash, because it loses information when it gets coded. if you want to encrypt/decrypt you should use MCrypt or another encryption class
This question already has answers here:
Closed 12 years ago.
Possible Duplicate:
Is it possible to decrypt md5 hashes?
Reversing an MD5 Hash
hi there is any way to decrypt md5 password field to allow user to edit password in form using javascript. or php.
MD5 is one way hashing algorithm - not a means of encrypting. As such, there's no means of decrypting it - only checking to see if another source input has the same hash.
No, there is no way, since hashing is not a reversible operation.
Your question is not very clear, but recovery of the origional string for hashes can be done with rainbowtables: http://en.wikipedia.org/wiki/Rainbow_table
(if the hash was salted, this will become troublesome ofcourse)
I wrote an app a few years back that brute-forces MD5 hashes against wordlists and previously-cracked MD5 hashes it finds via search engines, see if it comes up with anything for you:
http://bigtrapeze.com/md5/