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Ravi Kumar Gupta
Ravi Kumar Gupta

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Encode Decode JWT

#python #jwt #encode #decode

JWT stands for JSON Web Tokens.

A simple function to encode the content -

''' Encode the given text with given secret key. The default number of seconds for token validity is 600 seconds. ''' def encode_token(text, secret_key, validity_seconds = 600): import datetime, jwt try: payload = { 'exp': datetime.datetime.utcnow() + datetime.timedelta(days=0, seconds=validity_seconds), 'iat': datetime.datetime.utcnow(), 'secret': text } return jwt.encode( payload, secret_key, algorithm='HS256' ) except Exception as e: return e
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And to decode -

''' Decode the encoded token with given secret_key ''' def decode_token(auth_token, secret_key): import jwt try: payload = jwt.decode(auth_token, secret_key, algorithms='HS256') return {'auth': True, 'error': '', 'decoded': payload} except jwt.ExpiredSignatureError: return {'auth': False, 'error': 'Token expired'} except jwt.InvalidTokenError: return {'auth': False, 'error': 'Invalid token'} return {'auth': False, 'error': 'Some error'}
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Let's get to work -

Define a secret 

secret = 'This-is-my-super-secret'
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Encode the content 

encoded_data = encode_token('Something to encode', secret) print(encoded_data)
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This outputs as -

'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE2MjcyMjY4NDUsImlhdCI6MTYyNzIyNjI0NSwic2VjcmV0IjoiU29tZXRoaW5nIHRvIGVuY29kZSJ9.CombVr-757PXau8yeXtyjCLn54E3pGNntlnpoADnPRI'
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If You copy this to https://jwt.io you will see -

Alt Text

Decode the token

To decode the data you need the same secret

decoded_data = decode_token(encoded_data, secret) print(decoded_data['decoded']['secret'])
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This outputs to -
'Something to encode'

If you try to decode using some other secret key, the data won't be decoded correctly

decoded_data = decode_token(encoded_data, 'some-other-secret') print(decoded_data)
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This output as -

{'auth': False, 'error': 'Invalid token'}
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Hope these simple functions help you :)

You can follow me on Twitter — @kravigupta . You can also connect on LinkedIn — kravigupta.

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