Is my implementation of Salting and SHA-512 hashing passwords correct/secure?

cryptography, java, salt, security, sha512

Solution

No. It is not secure. Take a look at this line:

SecureRandom saltRandomizer = new SecureRandom();

I notice you don't specify a PRNG or provider. I'm no expert but I understand the SUN CSP default is to use sun.security.provider.NativePRNG on Solaris and Linux, which simply provides the output of /dev/urandom which may (or may not) be suitable for your needs (it is not, for example, recommended for the generation of cryptographic keys).

It is therefore recommended to always specify a PRNG and provider, as follows:

SecureRandom.getInstance("SHA1PRNG", "SUN");

Furthermore, it is advisable to:

- Periodically throw away the existing java.security.SecureRandom instance and create a new one. This will generate a new instance with a new seed.

- Periodically add new random material to the PRNG seed by making a call to java.security.SecureRandom.setSeed(java.security.SecureRandom.generateSeed(int)).

The point I'm making is that security is a complex topic that is so easy to get wrong. Don't try and homebrew a solution. Use an existing library. To quote Thomas Pornin's excellent answer:

Complexity is bad. Homemade is bad. New is bad.

Sources:

- https://security.stackexchange.com/questions/211/how-to-securely-hash-passwords

- http://en.wikipedia.org/wiki//dev/random

- http://www.cigital.com/justice-league-blog/2009/08/14/proper-use-of-javas-securerandom/

Problem

Is my implementation of Salting and SHA-512 hashing passwords correct/secure? I know that I should iterate the algorithm a couple of times on the salted password. Other than that what more should i implement to make it secure or is this enough? ``` public static String[] SHA512(String password) { //Generates the salt SecureRandom saltRandomizer = new SecureRandom(); byte[] salt = new byte[64]; //The same size as the output of SHA-512 (512 bits = 64 bytes) saltRandomizer.nextBytes(salt); String encodedSalt = Base64.encodeToString(salt, Base64.DEFAULT); //Prepends the salt to the password String saltedPassword = encodedSalt + password; //Hashed the salted password using SHA-512 MessageDigest digester; byte[] digest = null; try { digester = MessageDigest.getInstance("SHA-512"); digester.reset(); digester.update(saltedPassword.getBytes()); digest = digester.digest(); } catch (NoSuchAlgorithmException e) { System.out.println("No such algorithm"); e.printStackTrace(); } String[] passwordPlusSalt = new String[2]; passwordPlusSalt[0] = Base64.encodeToString(digest, Base64.DEFAULT); passwordPlusSalt[1] = encodedSalt; return passwordPlusSalt; } ``` Thanks in advance

Original source