Comment Hasher un mot de passe avec SHA-512 en Java?

veuillez arrêter D'utiliser des fonctions de hachage pour encoder les mots de passe! Ils ne fournissent pas la protection dont vous avez besoin. Au lieu de cela, vous devriez utiliser un algorithme comme PBKDF2, bcrypt, ou scrypt.

Références:

• http://blog.tjll.net/please-stop-hashing-passwords/
• http://security.blogoverflow.com/2011/11/why-passwords-should-be-hashed/
• https://crackstation.net/hashing-security.htm
• http://www.sitepoint.com/risks-challenges-password-hashing/
• http://security.blogoverflow.com/2013/09/about-secure-password-hashing/

utilisez Apache Commons Crypt, Il dispose de fonctions de crypt() basées sur SHA-512 qui génèrent des hachages salés qui sont même compatibles avec la crypt de libc et donc utilisables dans PHP/Perl/Python/C et la plupart des bases de données, aussi.

https://commons.apache.org/proper/commons-codec/apidocs/org/apache/commons/codec/digest/Crypt.html#Crypt%28%29

vous pouvez l'utiliser pour hacher un mot de passe en java si vous le souhaitez.

public static boolean isHashMatch(String password, // the password you want to check.
                                  String saltedHash, // the salted hash you want to check your password against.
                                  String hashAlgorithm, // the algorithm you want to use.
                                  String delimiter) throws NoSuchAlgorithmException // the delimiter that has been used to delimit the salt and the hash.
{
    // get the salt from the salted hash and decode it into a byte[].
    byte[] salt = Base64.getDecoder()
                        .decode(saltedHash.split(delimiter)[0]);
    // compute a new salted hash based on the provided password and salt.
    String pw_saltedHash = computeSaltedBase64Hash(password, 
                                                   salt,
                                                   hashAlgorithm,
                                                   delimiter);
    // check if the provided salted hash matches the salted hash we computed from the password and salt.
    return saltedHash.equals(pw_saltedHash);
}

public static String computeSaltedBase64Hash(String password, // the password you want to hash
                                             String hashAlgorithm, // the algorithm you want to use.
                                             String delimiter) throws NoSuchAlgorithmException // the delimiter that will be used to delimit the salt and the hash.
{
    // compute the salted hash with a random salt.
    return computeSaltedBase64Hash(password, null, hashAlgorithm, delimiter);
}

public static String computeSaltedBase64Hash(String password, // the password you want to hash
                                             byte[] salt, // the salt you want to use (uses random salt if null).
                                             String hashAlgorithm, // the algorithm you want to use.
                                             String delimiter) throws NoSuchAlgorithmException // the delimiter that will be used to delimit the salt and the hash.
{
    // transform the password string into a byte[]. we have to do this to work with it later.
    byte[] passwordBytes = password.getBytes();
    byte[] saltBytes;

    if(salt != null)
    {
        saltBytes = salt;
    }
        else
        {
            // if null has been provided as salt parameter create a new random salt.
            saltBytes = new byte[64];
            SecureRandom secureRandom = new SecureRandom();
            secureRandom.nextBytes(saltBytes);              
        }

    // MessageDigest converts our password and salt into a hash. 
    MessageDigest messageDigest = MessageDigest.getInstance(hashAlgorithm);
    // concatenate the salt byte[] and the password byte[].
    byte[] saltAndPassword = concatArrays(saltBytes, passwordBytes);
    // create the hash from our concatenated byte[].
    byte[] saltedHash = messageDigest.digest(saltAndPassword);
    // get java's base64 encoder for encoding.
    Encoder base64Encoder = Base64.getEncoder();
    // create a StringBuilder to build the result.
    StringBuilder result = new StringBuilder();

    result.append(base64Encoder.encodeToString(saltBytes)) // base64-encode the salt and append it.
          .append(delimiter) // append the delimiter (watch out! don't use regex expressions as delimiter if you plan to use String.split() to isolate the salt!)
          .append(base64Encoder.encodeToString(saltedHash)); // base64-encode the salted hash and append it.

    // return a salt and salted hash combo.
    return result.toString();
}

public static byte[] concatArrays(byte[]... arrays)
{   
    int concatLength = 0;
    // get the actual length of all arrays and add it so we know how long our concatenated array has to be.
    for(int i = 0; i< arrays.length; i++)
    {
        concatLength = concatLength + arrays[i].length;
    }
    // prepare our concatenated array which we're going to return later.
    byte[] concatArray = new byte[concatLength];
    // this index tells us where we write into our array.
    int index = 0;
    // concatenate the arrays.
    for(int i = 0; i < arrays.length; i++)
    {
        for(int j = 0; j < arrays[i].length; j++)
        {
            concatArray[index] = arrays[i][j];
            index++;
        }
    }
    // return the concatenated arrays.
    return concatArray;     
}

import java.nio.charset.StandardCharsets;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.apache.commons.codec.binary.Hex;

public String getHashSHA512(String StringToHash, String salt){
        String generatedPassword = null;
        try {
            MessageDigest md = MessageDigest.getInstance("SHA-512");
            md.update(salt.getBytes(StandardCharsets.UTF_8));
            byte[] bytes = md.digest(StringToHash.getBytes(StandardCharsets.UTF_8));
            generatedPassword = Hex.encodeHexString(bytes);
        }
        catch (NoSuchAlgorithmException e){
            e.printStackTrace();
        }
        return generatedPassword;
    }

il n'est pas recommandé d'utiliser des fonctions de hachage pour les mots de passe cependant, de nouveaux alogrithms comme bcrypt, ou scrypt existent

en utilisant Goyave:

Hashing.sha512().hashString(s, StandardCharsets.UTF_8).toString()

voici le algorithmes de hachage standard fourni par le Java MessageDigest:

1. MD2
2. MD5
3. SHA-1
4. SHA-256
5. SHA-384
6. SHA-512

Vous pouvez vérifier le nom que vous fournissez à la méthode de fabrique.

avec le hachage sûr combiner 3 composants de sel (de 150 caractères aléatoires chacun) à un sel d'utilisateur individuel (sel d'utilisateur de la table de base de données de l'utilisateur, sel général dans une table de base de données (changement mensuel avec travail cron) et cacher un peu de sel dans la bibliothèque d'application). Alignez le montant de la boucle pour le hachage sécurisé à vos besoins. Voir la réponse ci-dessus pour la méthode de hachage.

private static String generateSalt(int lenght){
    String abcCapitals = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    String abcLowerCase = "abcdefghijklmnopqrstuvwxyz";
    String numbers = "01234567890123456789";
    String characters = "!@#$%^&*!@#$%%^^&*";

    String total = abcCapitals + abcLowerCase + numbers + characters;

    String response = "";

    char letters[] = new char[lenght];
    for (int i=0; i<lenght-1; i++){
        Random r = new Random();
        char letter = total.charAt(r.nextInt(total.length()));
        letters[i] = letter;
    }

    response = Arrays.toString(letters).replaceAll("\s+","");
    response = response.replaceAll(",","");

    return response;
}

private static String getHash(String passwordToHash, String salt){
            String generatedPassword = null;
            try {
                 MessageDigest md = MessageDigest.getInstance("SHA-512");
                 md.update(salt.getBytes(StandardCharsets.UTF_8));
                 byte[] bytes = md.digest(passwordToHash.getBytes(StandardCharsets.UTF_8));
                 StringBuilder sb = new StringBuilder();
                 for(int i=0; i< bytes.length ;i++){
                    sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
                 }
                 generatedPassword = sb.toString();
                } 
               catch (NoSuchAlgorithmException e){
                   System.out.println(e);
               }
            return generatedPassword;
        }

    public static String getSecureHash(String password, String salt){
        String hash = getHash(password, salt);
        for (int i=0; i<20000; i++){
            hash = getHash(password, hash);      
        }
        return hash;
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        String salt = generateSalt(150);
        String salt2 = generateSalt(150);
        String salt3 = generateSalt(150);
        String someString = "This is some string!";

        String hash = getSecureHash(someString, salt + salt2 + salt3);
        System.out.println(hash);
    }