javascript - Why the decrypted key is not same as encrypted key? -

i wrote function encrypt or decrypt word. why decrypted key not same encrypted key?

function cryptage(action, password) {     var method = "aes-256-cbc";     if (action == "encrypt") {         var cipher = crypto.createcipher(method, password)         var crypted = cipher.update(password, 'utf8', 'hex')         crypted += cipher.final('hex');         return crypted;     } else if (action == "decrypt") {         var decipher = crypto.createdecipher(method, password)         decipher.setautopadding(false);         var decrypted = decipher.update(password, 'hex', 'utf8')         decrypted += decipher.final('utf8');         return decrypted;     } } 

when call var crypted = cryptage("encrypt", "test"), returns

cc1fbd73cb93106c3358636ff619bdbd

when call cryptage("decrypt", crypted), returns exactly

te�~��iӠ~{ }m

but no text, why ?

tl;dr => read the fine manual

the nodejs crypto module expects provide 2 things when create either cipher or decipher instance via 2 parameter overload of createcipher/createdecipher: method - name of actual openssl cipher use, , password, fed evp_bytestokey , result keybytes actual cipher instance

a new implementation using should inevitable lead punishment autor now... insecure , should replaced pbkdf2 example... know if you'd have read documentation... anyways ... want know why function not return desired output ... reason simple ...

you provide same value password , data , upon decryption want provide encryption result... can not work

have @ simplified encryption , decryption function/formula

encrypt(data,key) => ciphertext
decrypt(ciphertext,key) => data

this pretty straight forward , valid symetric ciphers (like aes, including modes of operation , keysizes, so... yes... aes 256 bit key in cipher-block-chaining mode)

so what's matter in case? this:
declare key , data same...
encrypt(key,key) => ciphertext
decrypt(ciphertext,ciphertext) => garbage

please note successful decryption key parameter encrypt , decrypt function must same, fails case

so approach mean need same original password decryption key parameter ... yes... need same value want decrypt ... input... decrypt function ...