class
	EL_RSA_PRIVATE_KEY

inherit
	EL_REFLECTIVE_RSA_KEY
		rename
			read as read_from
		redefine
			make_default
		end

	EL_MODULE_X509

	EL_MODULE_FILE_SYSTEM

	EL_FILE_OPEN_ROUTINES

-- Cannot inherit because of invariant: p * q ~ n
--	RSA_PRIVATE_KEY
--		rename
--			n as modulus,
--			p as prime_1,
--			q as prime_2,
--			d as private_exponent,
--			e as public_exponent
--		end

create
	make, make_default, make_from_primes, make_from_stored, make_from_pkcs1_table

feature {NONE} -- Initialization

	make (a_prime_1, a_prime_2, a_modulus, a_public_exponent: INTEGER_X)
		local
			phi: INTEGER_X
		do
			prime_1 := a_prime_1
			prime_2 := a_prime_2
			modulus := a_modulus
			public_exponent := a_public_exponent
			phi := (prime_1 - prime_1.one) * (prime_2 - prime_2.one)
			private_exponent := public_exponent.inverse_value (phi)
		ensure
			is_valid:
		end

	make_default
		do
			make_from_primes (17, 19)
		end

	make_from_primes (a_prime_1, a_prime_2: INTEGER_X)
		do
			make (a_prime_1, a_prime_2, a_prime_1 * a_prime_2, Default_exponent)
		end

	make_from_stored (file_path: FILE_PATH; encrypter: EL_AES_ENCRYPTER)
		-- make from binary file created with `store' routine
		do
			make_default
			if attached open_raw (file_path, Read) as file then
				copy (new_reader (encrypter).read_item (file))
				file.close
			end
		end

feature -- Access

	modulus: INTEGER_X

	prime_1: INTEGER_X

	prime_2: INTEGER_X

	private_exponent: INTEGER_X

	public_exponent: INTEGER_X

feature -- Status query

	is_default: BOOLEAN
		do
			Result := Current ~ Default_key
		end

	is_valid: BOOLEAN
		do
			Result := prime_1 * prime_2 ~ modulus
		end

feature -- Basic operations

	decrypt (cipher: INTEGER_X): INTEGER_X
		require
			is_valid: is_valid
		do
			result := cipher.powm_value (private_exponent, modulus)
		end

	sign (message: INTEGER_X): INTEGER_X
		do
			result := decrypt (message)
		end

	store (output_path: FILE_PATH; encrypter: EL_AES_ENCRYPTER)
		-- store as binary encrypted file
		do
			if attached open_raw (output_path, Write) as file then
				new_writer (encrypter).write (Current, file)
				file.close
			end
		end

feature -- Access

	prime_1_base_64: STRING
			--
		do
			Result := Base_64.encoded_special (prime_1.as_bytes, False)
		end

	prime_2_base_64: STRING
			--
		do
			Result := Base_64.encoded_special (prime_2.as_bytes, False)
		end

feature {NONE} -- Factory

	new_writer, new_reader (encrypter: EL_AES_ENCRYPTER): ECD_ENCRYPTABLE_READER_WRITER [like Current]
		do
			create Result.make (encrypter)
		end

feature {NONE} -- Constants

	Default_key: EL_RSA_PRIVATE_KEY
		once
			create Result.make_default
		end

	Field_hash: NATURAL = 1031955297

end