Class: Ccrypto::Java::HKDFEngine

Inherits:
Object
  • Object
show all
Includes:
DataConversion, TR::CondUtils
Defined in:
lib/ccrypto/java/engines/hkdf_engine.rb

Instance Method Summary collapse

Methods included from DataConversion

#from_b64, #from_hex, included, #to_b64, #to_b64_mime, #to_bin, #to_hex, #to_java_bytes, #to_str

Constructor Details

#initialize(*args, &block) ⇒ HKDFEngine

Returns a new instance of HKDFEngine.

Raises:

  • (KDFEngineException) 


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# File 'lib/ccrypto/java/engines/hkdf_engine.rb', line 10

def initialize(*args, &block)
  @config = args.first

  raise KDFEngineException, "KDF config is expected. Given #{@config}" if not @config.is_a?(Ccrypto::KDFConfig)
  raise KDFEngineException, "Output bit length (outBitLength) value is not given or not a positive value (#{@config.outBitLength})" if is_empty?(@config.outBitLength) or @config.outBitLength <= 0


  @config.salt = SecureRandom.random_bytes(16) if is_empty?(@config.salt)
end

Instance Method Details

#derive(input, output = :binary) ⇒ Object 



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# File 'lib/ccrypto/java/engines/hkdf_engine.rb', line 20

def derive(input, output = :binary)
  begin

    case @config.digest
    when :sha1
      dig = org.bouncycastle.crypto.digests.SHA1Digest.new
    when :sha224
      dig = org.bouncycastle.crypto.digests.SHA224Digest.new
    when :sha256
      dig = org.bouncycastle.crypto.digests.SHA256Digest.new
    when :sha384
      dig = org.bouncycastle.crypto.digests.SHA384Digest.new
    when :sha512
      dig = org.bouncycastle.crypto.digests.SHA512Digest.new
    when :sha3_224
      dig = org.bouncycastle.crypto.digests.SHA3Digest.new(224)
    when :sha3_256
      dig = org.bouncycastle.crypto.digests.SHA3Digest.new(256)
    when :sha3_384
      dig = org.bouncycastle.crypto.digests.SHA3Digest.new(384)
    when :sha3_512
      dig = org.bouncycastle.crypto.digests.SHA3Digest.new(512)
    else
      raise KDFEngineException, "Digest #{@config.digest} not supported"
    end

    @config.info = "" if @config.info.nil?

    hkdf = org.bouncycastle.crypto.generators.HKDFBytesGenerator.new(dig)
    hkdfParam = org.bouncycastle.crypto.params.HKDFParameters.new(to_java_bytes(input), to_java_bytes(@config.salt) ,to_java_bytes(@config.info))
    hkdf.init(hkdfParam)

    out = ::Java::byte[@config.outBitLength/8].new
    hkdf.generateBytes(out, 0, out.length)

    case output
    when :b64
      to_b64(out)
    when :hex
      to_hex(out)
    else
      out
    end

  rescue Exception => ex
    raise KDFEngineException, ex
  end
  
end