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How can I store a dictionary in a file which I can encrypt?

I'm pretty new to Python and programming in general and am currently working on a little password manager. Thus far I have a script which can encode a txt file using the cryptography library. I am now wondering if it is possible to store information on a website or an account with a corresponding Password in the txt file or if I need to use something else than a txt file. What would you recommend?

The easiest way to do that is convert that dict to json and encrypt the string result.
It's easy convert to dict too. What I advise you to do if you're using this only for auth, is save like a key value store. Example:
{
"<user>": "<password>",
"<user2>" : "<password2>"
}
On this datastruct the code will be always O(1).

Yes, you can use a text file. That is not a problem. The text file will contain encrypted text.
Depending upon how secure and how many unique passwords, you probably want a salted encryption techique.
I would recommend passlib.
I will give as an example some code I recently made, and explain it (although I am not a cryptography expert):
from passlib.context import CryptContext
CRYPTO_CTX = CryptContext(schemes=["bcrypt"], deprecated="auto") # This means only use `'bcrypt'`.
#app.post("/login")
def login_user(user, db):
db_user = crud.get_user_by_username(db, username=user.username)
if db_user is None:
raise HTTPException(
status_code=400, detail=f"No username {user.username} found."
)
if not CRYPTO_CTX.verify(user.password, db_user.hashed_password): ## This is the essential portion
raise HTTPException(status_code=400, detail=f"Incorrect password.")
db_user = crud.update_user(db, db_user, {"last_visit": datetime.now(timezone.utc)})
return {"user": db_user}
This code is, as I said, for a website, and it is using FastAPI. I have removed some stuff for clarity while hopefully keeping enough context. Here is the breakdown:
You need to make a "Cryptographic context", which will know which hashing scheme(s) to use.
In my case, I am only using and allowing 'bcrypt', a best practice choice for 2020 (but you can choose others for flexibility).
I then create a '/login' web route, which is a URI endpoint that triggers a function.
That function receives user information from an HTTP POST that an end user submitted (and a database session).
The user is then searched on the database backend. Presuming she is found, the submitted password in the POST is compared to the password in the database, but that password is cryptographically protected.
Let's zoom in on that comparison:
if not CRYPTO_CTX.verify(user.password, db_user.hashed_password):
We are providing a plain text string (user.password) and a hashed string (db_user.hashed_password) to our CRYPTO_CTXs verify method. That is all that is needed, since the passlib library is doing all the heavy lifting.
How was the password encrypted? That was just as easy:
hashed_password = CRYPTO_CTX.hash(user.password)
And this does not just encrypt the password, it also salts it. In short, this means that if somehow the encryption were hacked, it would only work for that one entry. With salting, it's a two-step encryption process:
Create a password. Eg, 'Elderberries'
Add a salt to it: 'Elderberries34(*&#arst##!'
Hash that entire thing: 'B4B6603ABC670967E99C7E7F1389E40CD16E78AD38EB1468EC2AA1E62B8BED3A'

Hashing Password in .py file

how i said in the title, i want the password to be hashed when is saved. Its possible with this?
def __OnClickSaveLoginButton(self):
id = self.idEditLine.GetText()
pwd = self.pwdEditLine.GetText()
if (len(id) == 0 or len(pwd) == 0):
self.PopupNotifyMessage("ID and Password required",self.SetIDEditLineFocus)
return
file_object = open("account.cfg", "w")
file_object.write(id+"\n"+pwd)
self.PopupNotifyMessage("Saved.",self.SetIDEditLineFocus)
file_object.close()

You'll want to use the python hashlib. An example could look something like this:
import hashlib
def valid_password(userid, password):
user = get_user(userid)
pw_hash = hashlib.sha256(password).hexdigest()
if user.hash == pw_hash:
return True
return False
Also I recommend reviewing some password storage best practices noted in this SO
Edit: I used sh256 in this example, but that is more useful as a message digest. A better use would be hashlib.pbkdf2_hmac or another key derivation function. There is a good write up here.

If you're going to hash passwords in Python, as nudies mentioned, hashlib.pbkdf2_hmac is correct.
If you want to save the result in Base64, that's a reasonable option, as it turns it into a character string.
Just remember you also have to store the salt and the number of iterations; choose as high a number of iterations as your CPU can stand.
DO NOT request more bytes of output than the native hash function can support; for instance, PBKDF2-HMAC-SHA-512 caps out at 64 bytes for password hashing; the others less.
I have a fully working example at my github repository, including test vectors for all the normal SHA variants, of which the core piece is
import argparse,hashlib,base64,timeit
BinaryOutput = hashlib.pbkdf2_hmac('sha512',args.password, args.salt, args.iterations, args.outputBytes)
BinaryOutput.encode('base64')

Python with etc/Shadow

so I'm writing this program that needs to check the password hash in etc/shadow and compare it to the password the user entered. I tried encrypting the password with hashlib.sha512, but the result was not the same. I think it's salted some how, but I don't know if it uses a universal salt or how I can get the salt each time.
tldr; I need a way for a user to enter a password, then have the program hash it and check it against the etc/shadow. Any ideas?

Try this https://pypi.python.org/pypi/pam . First link in google by python pam.
Look at distribution package manager for python-pam if exists. Else install with pip or easy_install.
Small example:
>>> import pam
>>> pam.authenticate('fred', 'fredspassword')
False

>>> import crypt
>>> line = 'bob:$1$qda8YAO9$rBiov9uVJlH1/97cbcyEt.:15965:0:99999:7:::'
>>> encript = line.split(':')[1]
>>> encript
--> '$1$qda8YAO9$rBiov9uVJlH1/97cbcyEt.'
>>> i = encript.rfind('$')
>>> salt = encript[:i]
>>> salt
--> '$1$qda8YAO9'
>>> crypt.crypt('bob_password',salt)
--> '$1$qda8YAO9$rBiov9uVJlH1/97cbcyEt.'
>>> encript
--> '$1$qda8YAO9$rBiov9uVJlH1/97cbcyEt.'

The passwd field is not just a SHA-512 hash of the password.*
This is explained in the crypt manpage. The format is $id$salt$hash, where id specifies the hash method (1 for MD5, 2a for Blowfish, 5 for SHA-256, 6 for SHA-512), salt specifies the salt to use with that algorithm, and hash specifies what the result should be.
As the manpage implies, you can actually pass the whole $id$salt$ to the crypt function in place of the salt, and it will automatically use the appropriate algorithm. This wouldn't be too hard to do via, say, ctypes.
At any rate, what you're doing is almost certainly a bad idea. You'll need to run as root in order to have access to /etc/shadow, and you'll need to simulate more than just password verification if you actually want to verify that the user can log in, and of course you'll need to handle secure input and make sure you don't end up saving the password in plaintext somewhere and so on. It's a lot simpler and safer to just let PAM do the work for you.
* I believe that in theory, it can be—if it doesn't start with a $ it's interpreted as some legacy format… presumably meaning it's interpreted as POSIX crypt using the DES algorithm.

How to authenticate hashed(sha1) password in Python?

I am trying to retrieve the password and authenticate from the Galaxy framework. I successfully retrieve the password it's in hashed(sha1) format. How do I authenticate this with the password input by the user? My first guess would be converting hashed(sha1) into normal string and authenticating. Is that possible? If it is, how can I convert it into the string?

You can't. It would be extremely hard to get the plain text from its hash code, that's exactly the reason why we had invented hash. Try the opposite: convert the plain text to hash and then compare.
How to convert:
import hashlib
s = "plain"
h = hashlib.sha1(s).hexdigest()

... My first guess would be converting hashed(sha1) into normal string ...
That's what cryptographic hash functions try to prevent (among other things) - this property is called pre-image resistance.
The basic steps would be the other way around:
take user input
compute hash over user input
compare hashed user input to stored credentials/hashes

Salt and hash a password in Python

This code is supposed to hash a password with a salt. The salt and hashed password are being saved in the database. The password itself is not.
Given the sensitive nature of the operation, I wanted to make sure everything was kosher.
import hashlib
import base64
import uuid
password = 'test_password'
salt = base64.urlsafe_b64encode(uuid.uuid4().bytes)
t_sha = hashlib.sha512()
t_sha.update(password+salt)
hashed_password = base64.urlsafe_b64encode(t_sha.digest())

Based on the other answers to this question, I've implemented a new approach using bcrypt.
Why use bcrypt
If I understand correctly, the argument to use bcrypt over SHA512 is that bcrypt is designed to be slow. bcrypt also has an option to adjust how slow you want it to be when generating the hashed password for the first time:
# The '12' is the number that dictates the 'slowness'
bcrypt.hashpw(password, bcrypt.gensalt( 12 ))
Slow is desirable because if a malicious party gets their hands on the table containing hashed passwords, then it is much more difficult to brute force them.
Implementation
def get_hashed_password(plain_text_password):
# Hash a password for the first time
# (Using bcrypt, the salt is saved into the hash itself)
return bcrypt.hashpw(plain_text_password, bcrypt.gensalt())
def check_password(plain_text_password, hashed_password):
# Check hashed password. Using bcrypt, the salt is saved into the hash itself
return bcrypt.checkpw(plain_text_password, hashed_password)
Notes
I was able to install the library pretty easily in a linux system using:
pip install py-bcrypt
However, I had more trouble installing it on my windows systems. It appears to need a patch. See this Stack Overflow question: py-bcrypt installing on win 7 64bit python

EDIT: This answer is wrong. A single iteration of SHA512 is fast, which makes it inappropriate for use as a password hashing function. Use one of the other answers here instead.
Looks fine by me. However, I'm pretty sure you don't actually need base64. You could just do this:
import hashlib, uuid
salt = uuid.uuid4().hex
hashed_password = hashlib.sha512(password + salt).hexdigest()
If it doesn't create difficulties, you can get slightly more efficient storage in your database by storing the salt and hashed password as raw bytes rather than hex strings. To do so, replace hex with bytes and hexdigest with digest.

Edit:
The library suggested in this answer is now outdated, and the hashlib key derivation functionality mentioned in this answer: https://stackoverflow.com/a/56915300/893857 is a good suggestion to use nowadays.
Original Answer
The smart thing is not to write the crypto yourself but to use something like passlib: https://passlib.readthedocs.io/en/stable/#
It is easy to mess up writing your crypto code in a secure way. The nasty thing is that with non crypto code you often immediately notice it when it is not working since your program crashes. While with crypto code you often only find out after it is to late and your data has been compromised. Therefore I think it is better to use a package written by someone else who is knowledgeable about the subject and which is based on battle tested protocols.
Also passlib has some nice features which make it easy to use and also easy to upgrade to a newer password hashing protocol if an old protocol turns out to be broken.
Also just a single round of sha512 is more vulnerable to dictionary attacks. sha512 is designed to be fast and this is actually a bad thing when trying to store passwords securely. Other people have thought long and hard about all this sort issues so you better take advantage of this.

As of Python 3.4, the hashlib module in the standard library contains key derivation functions which are "designed for secure password hashing".
So use one of those, like hashlib.pbkdf2_hmac, with a salt generated using os.urandom:
from typing import Tuple
import os
import hashlib
import hmac
def hash_new_password(password: str) -> Tuple[bytes, bytes]:
"""
Hash the provided password with a randomly-generated salt and return the
salt and hash to store in the database.
"""
salt = os.urandom(16)
pw_hash = hashlib.pbkdf2_hmac('sha256', password.encode(), salt, 100000)
return salt, pw_hash
def is_correct_password(salt: bytes, pw_hash: bytes, password: str) -> bool:
"""
Given a previously-stored salt and hash, and a password provided by a user
trying to log in, check whether the password is correct.
"""
return hmac.compare_digest(
pw_hash,
hashlib.pbkdf2_hmac('sha256', password.encode(), salt, 100000)
)
# Example usage:
salt, pw_hash = hash_new_password('correct horse battery staple')
assert is_correct_password(salt, pw_hash, 'correct horse battery staple')
assert not is_correct_password(salt, pw_hash, 'Tr0ub4dor&3')
assert not is_correct_password(salt, pw_hash, 'rosebud')
Note that:
The use of a 16-byte salt and 100000 iterations of PBKDF2 match the minimum numbers recommended in the Python docs. Further increasing the number of iterations will make your hashes slower to compute, and therefore more secure.
os.urandom always uses a cryptographically secure source of randomness
hmac.compare_digest, used in is_correct_password, is basically just the == operator for strings but without the ability to short-circuit, which makes it immune to timing attacks. That probably doesn't really provide any extra security value, but it doesn't hurt, either, so I've gone ahead and used it.
For theory on what makes a good password hash and a list of other functions appropriate for hashing passwords with, see https://security.stackexchange.com/q/211/29805.

For this to work in Python 3 you'll need to UTF-8 encode for example:
hashed_password = hashlib.sha512(password.encode('utf-8') + salt.encode('utf-8')).hexdigest()
Otherwise you'll get:
Traceback (most recent call last):
File "", line 1, in
hashed_password = hashlib.sha512(password + salt).hexdigest()
TypeError: Unicode-objects must be encoded before hashing

passlib seems to be useful if you need to use hashes stored by an existing system. If you have control of the format, use a modern hash like bcrypt or scrypt. At this time, bcrypt seems to be much easier to use from python.
passlib supports bcrypt, and it recommends installing py-bcrypt as a backend: http://pythonhosted.org/passlib/lib/passlib.hash.bcrypt.html
You could also use py-bcrypt directly if you don't want to install passlib. The readme has examples of basic use.
see also: How to use scrypt to generate hash for password and salt in Python

I don' want to resurrect an old thread, but... anyone who wants to use a modern up to date secure solution, use argon2.
https://pypi.python.org/pypi/argon2_cffi
It won the the password hashing competition. ( https://password-hashing.net/ ) It is easier to use than bcrypt, and it is more secure than bcrypt.

I did the same thing in NodeJs before:
echo "console.log(require('crypto').createHmac('sha256', 'salt').update('password').digest('hex'))" | node
it's equivalent in python is:
python3 -c 'import hashlib;import base64;import hmac;print(hmac.new(b"salt", "password".encode(), hashlib.sha256).hexdigest())'
And the equivalent shell command is:
echo -n "password" | openssl sha256 -hmac "salt"