Class: BCrypt::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/bcrypt/engine.rb,
ext/mri/bcrypt_ext.c

Overview

A Ruby wrapper for the bcrypt() C extension calls and the Java calls.

Constant Summary

DEFAULT_COST =

The default computational expense parameter.

10
MIN_COST =

The minimum cost supported by the algorithm.

4
MAX_SALT_LENGTH =

Maximum possible size of bcrypt() salts.

16

Class Method Summary (collapse)

Class Method Details

+ (Object) autodetect_cost(salt)

Autodetects the cost from the salt string.



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# File 'lib/bcrypt/engine.rb', line 111

def self.autodetect_cost(salt)
  salt[4..5].to_i
end

+ (Object) calibrate(upper_time_limit_in_ms)

Returns the cost factor which will result in computation times less than upper_time_limit_in_ms.

Example:

BCrypt::Engine.calibrate(200)  #=> 10
BCrypt::Engine.calibrate(1000) #=> 12

# should take less than 200ms
BCrypt::Password.create("woo", :cost => 10)

# should take less than 1000ms
BCrypt::Password.create("woo", :cost => 12)


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# File 'lib/bcrypt/engine.rb', line 101

def self.calibrate(upper_time_limit_in_ms)
  40.times do |i|
    start_time = Time.now
    Password.create("testing testing", :cost => i+1)
    end_time = Time.now - start_time
    return i if end_time * 1_000 > upper_time_limit_in_ms
  end
end

+ (Object) cost

Returns the cost factor that will be used if one is not specified when creating a password hash. Defaults to DEFAULT_COST if not set.



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# File 'lib/bcrypt/engine.rb', line 22

def self.cost
  @cost || DEFAULT_COST
end

+ (Object) cost=(cost)

Set a default cost factor that will be used if one is not specified when creating a password hash.

Example:

BCrypt::Engine::DEFAULT_COST            #=> 10
BCrypt::Password.create('secret').cost  #=> 10

BCrypt::Engine.cost = 8
BCrypt::Password.create('secret').cost  #=> 8

# cost can still be overridden as needed
BCrypt::Password.create('secret', :cost => 6).cost  #=> 6


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# File 'lib/bcrypt/engine.rb', line 39

def self.cost=(cost)
  @cost = cost
end

+ (Object) generate_salt(cost = self.cost)

Generates a random salt with a given computational cost.



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# File 'lib/bcrypt/engine.rb', line 62

def self.generate_salt(cost = self.cost)
  cost = cost.to_i
  if cost > 0
    if cost < MIN_COST
      cost = MIN_COST
    end
    if RUBY_PLATFORM == "java"
      Java.bcrypt_jruby.BCrypt.gensalt(cost)
    else
      prefix = "$2a$05$CCCCCCCCCCCCCCCCCCCCC.E5YPO9kmyuRGyh0XouQYb4YMJKvyOeW"
      __bc_salt(prefix, cost, OpenSSL::Random.random_bytes(MAX_SALT_LENGTH))
    end
  else
    raise Errors::InvalidCost.new("cost must be numeric and > 0")
  end
end

+ (Object) hash_secret(secret, salt, _ = nil)

Given a secret and a valid salt (see BCrypt::Engine.generate_salt) calculates a bcrypt() password hash.



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# File 'lib/bcrypt/engine.rb', line 45

def self.hash_secret(secret, salt, _ = nil)
  if valid_secret?(secret)
    if valid_salt?(salt)
      if RUBY_PLATFORM == "java"
        Java.bcrypt_jruby.BCrypt.hashpw(secret.to_s, salt.to_s)
      else
        __bc_crypt(secret.to_s, salt)
      end
    else
      raise Errors::InvalidSalt.new("invalid salt")
    end
  else
    raise Errors::InvalidSecret.new("invalid secret")
  end
end

+ (Boolean) valid_salt?(salt)

Returns true if salt is a valid bcrypt() salt, false if not.

Returns:

  • (Boolean)


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# File 'lib/bcrypt/engine.rb', line 80

def self.valid_salt?(salt)
  !!(salt =~ /^\$[0-9a-z]{2,}\$[0-9]{2,}\$[A-Za-z0-9\.\/]{22,}$/)
end

+ (Boolean) valid_secret?(secret)

Returns true if secret is a valid bcrypt() secret, false if not.

Returns:

  • (Boolean)


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# File 'lib/bcrypt/engine.rb', line 85

def self.valid_secret?(secret)
  secret.respond_to?(:to_s)
end