module m_crypt
implicit none

contains

    function hash(phrase)
    use utilities, only: get_one_line_output_shell_command
    implicit none
    
    character(len=*), intent(in)::phrase
    character(len=:), pointer::hash

    character(len=256)::tempout
    
        call get_one_line_output_shell_command('mkpasswd -m sha-512 "'//trim(phrase)//'"', &
                                               tempout)
        
        allocate(character(len=len_trim(tempout)) :: hash)
        hash = trim(tempout)
    
    end function hash
    
    function verify_hash(phrase, hashed)
    use utilities, only: get_one_line_output_shell_command
    implicit none
    
        character(len=*), intent(in)::phrase, hashed
        logical::verify_hash
        
        character(len=256)::tempout
        character(32)::salt
        integer::i
        
        i = index(hashed(4:len_trim(hashed)), "$")
        salt = hashed(4:i+2)
        
        call get_one_line_output_shell_command('mkpasswd -m sha-512 -S '//trim(salt)//' "'//trim(phrase)//'"', &
                                               tempout)
        
        verify_hash = (trim(tempout) == trim(hashed))
        
    end function verify_hash
    
end module m_crypt