How to store passwords safely in the database and how to validate a password? Letโs take a look.
๐๐ก๐ข๐ง๐ ๐ฌ ๐๐๐ ๐ญ๐จ ๐๐จ
๐น Storing passwords in plain text is not a good idea because anyone with internal access can see them.
๐น Storing password hashes directly is not sufficient because it is pruned to precomputation attacks, such as rainbow tables.
๐น To mitigate precomputation attacks, we salt the passwords.
๐๐ก๐๐ญ ๐ข๐ฌ ๐ฌ๐๐ฅ๐ญ?
According to OWASP guidelines, โa salt is a unique, randomly generated string that is added to each password as part of the hashing processโ.
๐๐จ๐ฐ ๐ญ๐จ ๐ฌ๐ญ๐จ๐ซ๐ ๏ฟฝ๏ฟฝ๏ฟฝ๏ฟฝ ๐ฉ๐๐ฌ๐ฌ๐ฐ๐จ๐ซ๐ ๐๐ง๐ ๐ฌ๐๐ฅ๐ญ?
1๏ธโฃ A salt is not meant to be secret and it can be stored in plain text in the database. It is used to ensure the hash result is unique to each password.
2๏ธโฃ The password can be stored in the database using the following format: ๐ฉ๐ข๐ด๐ฉ( ๐ฑ๐ข๐ด๐ด๐ธ๐ฐ๐ณ๐ฅ + ๐ด๐ข๐ญ๐ต).
๐๐จ๐ฐ ๐ญ๐จ ๐ฏ๐๐ฅ๐ข๐๐๐ญ๐ ๐ ๐ฉ๐๐ฌ๐ฌ๐ฐ๐จ๐ซ๐?
To validate a password, it can go through the following process:
1๏ธโฃ A client enters the password.
2๏ธโฃ The system fetches the corresponding salt from the database.
3๏ธโฃ The system appends the salt to the password and hashes it. Letโs call the hashed value H1.
4๏ธโฃ The system compares H1 and H2, where H2 is the hash stored in the database. If they are the same, the password is valid.
Over to you: what other mechanisms can we use to ensure password safety?
โ
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