程序包 me.insidezhou.southernquiet.util

类 BCrypt

  • public class BCrypt
extends java.lang.Object
    BCrypt implements OpenBSD-style Blowfish password hashing using the scheme described in "A Future-Adaptable Password Scheme" by Niels Provos and David Mazieres.

    This password hashing system tries to thwart off-line password cracking using a computationally-intensive hashing algorithm, based on Bruce Schneier's Blowfish cipher. The work factor of the algorithm is parameterised, so it can be increased as computers get faster.

    Usage is really simple. To hash a password for the first time, call the hashpw method with a random salt, like this:

    String pw_hash = BCrypt.hashpw(plain_password, BCrypt.gensalt());

    To check whether a plaintext password matches one that has been hashed previously, use the checkpw method:

    if (BCrypt.checkpw(candidate_password, stored_hash))
        System.out.println("It matches");
    else
        System.out.println("It does not match");

    The gensalt() method takes an optional parameter (log_rounds) that determines the computational complexity of the hashing:

    String strong_salt = BCrypt.gensalt(10)
    String stronger_salt = BCrypt.gensalt(12)

    The amount of work increases exponentially (2**log_rounds), so each increment is twice as much work. The default log_rounds is 10, and the valid range is 4 to 31.

    • 构造器概要

      构造器 
      构造器 说明
      BCrypt()  

    • 方法概要

      所有方法 静态方法 具体方法 
      修饰符和类型 方法 说明
      static boolean checkpw​(java.lang.String plaintext, java.lang.String hashed)
      Check that a plaintext password matches a previously hashed one
      static java.lang.String gensalt()
      Generate a salt for use with the BCrypt.hashpw() method, selecting a reasonable default for the number of hashing rounds to apply
      static java.lang.String gensalt​(int log_rounds)
      Generate a salt for use with the BCrypt.hashpw() method
      static java.lang.String gensalt​(int log_rounds, java.security.SecureRandom random)
      Generate a salt for use with the BCrypt.hashpw() method
      static java.lang.String hashpw​(java.lang.String password, java.lang.String salt)
      Hash a password using the OpenBSD bcrypt scheme

      • 从类继承的方法 java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • 构造器详细资料

      • BCrypt

        public BCrypt()

    • 方法详细资料

      • hashpw

        public static java.lang.String hashpw​(java.lang.String password,
                                      java.lang.String salt)
                               throws java.lang.IllegalArgumentException
        Hash a password using the OpenBSD bcrypt scheme
        参数:
        password - the password to hash
        salt - the salt to hash with (perhaps generated using BCrypt.gensalt)
        返回:
        the hashed password
        抛出:
        java.lang.IllegalArgumentException - if invalid salt is passed

      • gensalt

        public static java.lang.String gensalt​(int log_rounds,
                                       java.security.SecureRandom random)
        Generate a salt for use with the BCrypt.hashpw() method
        参数:
        log_rounds - the log2 of the number of rounds of hashing to apply - the work factor therefore increases as 2**log_rounds. Minimum 4, maximum 31.
        random - an instance of SecureRandom to use
        返回:
        an encoded salt value

      • gensalt

        public static java.lang.String gensalt​(int log_rounds)
        Generate a salt for use with the BCrypt.hashpw() method
        参数:
        log_rounds - the log2 of the number of rounds of hashing to apply - the work factor therefore increases as 2**log_rounds. Minimum 4, maximum 31.
        返回:
        an encoded salt value

      • gensalt

        public static java.lang.String gensalt()
        Generate a salt for use with the BCrypt.hashpw() method, selecting a reasonable default for the number of hashing rounds to apply
        返回:
        an encoded salt value

      • checkpw

        public static boolean checkpw​(java.lang.String plaintext,
                              java.lang.String hashed)
        Check that a plaintext password matches a previously hashed one
        参数:
        plaintext - the plaintext password to verify
        hashed - the previously-hashed password
        返回:
        true if the passwords match, false otherwise