# module OpenSSL::Buffering

`OpenSSL` `IO` buffering mix-in module.

This module allows an `OpenSSL::SSL::SSLSocket` to behave like an `IO`.

You typically won’t use this module directly, you can see it implemented in `OpenSSL::SSL::SSLSocket`.

### Constants

BLOCK_SIZE

  Default size to read from or write to the SSLSocket for buffer operations.

### Attributes

sync[RW]

The “sync mode” of the SSLSocket.

See `IO#sync` for full details.

### Public Class Methods

new(*) click to toggle source

Creates an instance of OpenSSL’s buffering `IO` module.

Calls superclass method

    # File ext/openssl/lib/openssl/buffering.rb, line 63
    def initialize(*)
      super
      @eof = false
      @rbuffer = Buffer.new
      @sync = @io.sync
    end

### Public Instance Methods

<<(s) click to toggle source

Writes s to the stream. s will be converted to a `String` using `.to_s` method.

    # File ext/openssl/lib/openssl/buffering.rb, line 422
    def <<(s)
      do_write(s)
      self
    end

close() click to toggle source

Closes the SSLSocket and flushes any unwritten data.

    # File ext/openssl/lib/openssl/buffering.rb, line 483
    def close
      flush rescue nil
      sysclose
    end

each(eol=$/) { |line| ... } click to toggle source

Executes the block for every line in the stream where lines are separated by eol.

See also `gets`

    # File ext/openssl/lib/openssl/buffering.rb, line 259
    def each(eol=$/)
      while line = self.gets(eol)
        yield line
      end
    end

Also aliased as: each_line
each_byte() { |byte| ... } click to toggle source

Calls the given block once for each byte in the stream.

    # File ext/openssl/lib/openssl/buffering.rb, line 300
    def each_byte # :yields: byte
      while c = getc
        yield(c.ord)
      end
    end

each_line(eol=$/)
Alias for: each
eof()
Alias for: eof?
eof?() click to toggle source

Returns true if the stream is at file which means there is no more data to be read.

    # File ext/openssl/lib/openssl/buffering.rb, line 331
    def eof?
      fill_rbuff if !@eof && @rbuffer.empty?
      @eof && @rbuffer.empty?
    end

Also aliased as: eof
flush() click to toggle source

Flushes buffered data to the SSLSocket.

    # File ext/openssl/lib/openssl/buffering.rb, line 471
    def flush
      osync = @sync
      @sync = true
      do_write ""
      return self
    ensure
      @sync = osync
    end

getbyte → 81 click to toggle source

Get the next 8bit byte from ‘ssl`. Returns `nil` on EOF

    # File ext/openssl/lib/openssl/buffering.rb, line 108
    def getbyte
      byte = read(1)
      byte && byte.unpack1("C")
    end

getc() click to toggle source

Reads one character from the stream. Returns nil if called at end of file.

    # File ext/openssl/lib/openssl/buffering.rb, line 293
    def getc
      read(1)
    end

gets(eol=$/, limit=nil) click to toggle source

Reads the next “line” from the stream. Lines are separated by eol. If limit is provided the result will not be longer than the given number of bytes.

eol may be a `String` or `Regexp`.

Unlike `IO#gets` the line read will not be assigned to +$_+.

Unlike `IO#gets` the separator must be provided if a limit is provided.

    # File ext/openssl/lib/openssl/buffering.rb, line 235
    def gets(eol=$/, limit=nil)
      idx = @rbuffer.index(eol)
      until @eof
        break if idx
        fill_rbuff
        idx = @rbuffer.index(eol)
      end
      if eol.is_a?(Regexp)
        size = idx ? idx+$&.size : nil
      else
        size = idx ? idx+eol.size : nil
      end
      if size && limit && limit >= 0
        size = [size, limit].min
      end
      consume_rbuff(size)
    end

print(*args) click to toggle source

Writes args to the stream.

See `IO#print` for full details.

    # File ext/openssl/lib/openssl/buffering.rb, line 450
    def print(*args)
      s = Buffer.new
      args.each{ |arg| s << arg.to_s }
      do_write(s)
      nil
    end

printf(s, *args) click to toggle source

Formats and writes to the stream converting parameters under control of the format string.

See `Kernel#sprintf` for format string details.

    # File ext/openssl/lib/openssl/buffering.rb, line 463
    def printf(s, *args)
      do_write(s % args)
      nil
    end

puts(*args) click to toggle source

Writes args to the stream along with a record separator.

See `IO#puts` for full details.

    # File ext/openssl/lib/openssl/buffering.rb, line 432
    def puts(*args)
      s = Buffer.new
      if args.empty?
        s << "\n"
      end
      args.each{|arg|
        s << arg.to_s
        s.sub!(/(?<!\n)\z/, "\n")
      }
      do_write(s)
      nil
    end

read(size=nil, buf=nil) click to toggle source

Reads size bytes from the stream. If buf is provided it must reference a string which will receive the data.

See `IO#read` for full details.

    # File ext/openssl/lib/openssl/buffering.rb, line 119
    def read(size=nil, buf=nil)
      if size == 0
        if buf
          buf.clear
          return buf
        else
          return ""
        end
      end
      until @eof
        break if size && size <= @rbuffer.size
        fill_rbuff
      end
      ret = consume_rbuff(size) || ""
      if buf
        buf.replace(ret)
        ret = buf
      end
      (size && ret.empty?) ? nil : ret
    end

read_nonblock(maxlen, buf=nil, exception: true) click to toggle source

Reads at most maxlen bytes in the non-blocking manner.

When no data can be read without blocking it raises `OpenSSL::SSL::SSLError` extended by `IO::WaitReadable` or `IO::WaitWritable`.

`IO::WaitReadable` means `SSL` needs to read internally so `read_nonblock` should be called again when the underlying `IO` is readable.

`IO::WaitWritable` means `SSL` needs to write internally so `read_nonblock` should be called again after the underlying `IO` is writable.

`OpenSSL::Buffering#read_nonblock` needs two rescue clause as follows:

    # emulates blocking read (readpartial).
    begin
      result = ssl.read_nonblock(maxlen)
    rescue IO::WaitReadable
      IO.select([io])
      retry
    rescue IO::WaitWritable
      IO.select(nil, [io])
      retry
    end

Note that one reason that `read_nonblock` writes to the underlying `IO` is when the peer requests a new TLS/SSL handshake. See openssl the FAQ for more details. www.openssl.org/support/faq.html

By specifying a keyword argument exception to `false`, you can indicate that `read_nonblock` should not raise an IO::Wait*able exception, but return the symbol `:wait_writable` or `:wait_readable` instead. At EOF, it will return `nil` instead of raising `EOFError`.

    # File ext/openssl/lib/openssl/buffering.rb, line 204
    def read_nonblock(maxlen, buf=nil, exception: true)
      if maxlen == 0
        if buf
          buf.clear
          return buf
        else
          return ""
        end
      end
      if @rbuffer.empty?
        return sysread_nonblock(maxlen, buf, exception: exception)
      end
      ret = consume_rbuff(maxlen)
      if buf
        buf.replace(ret)
        ret = buf
      end
      ret
    end

readchar() click to toggle source

Reads a one-character string from the stream. Raises an `EOFError` at end of file.

    # File ext/openssl/lib/openssl/buffering.rb, line 310
    def readchar
      raise EOFError if eof?
      getc
    end

readline(eol=$/) click to toggle source

Reads a line from the stream which is separated by eol.

Raises `EOFError` if at end of file.

    # File ext/openssl/lib/openssl/buffering.rb, line 284
    def readline(eol=$/)
      raise EOFError if eof?
      gets(eol)
    end

readlines(eol=$/) click to toggle source

Reads lines from the stream which are separated by eol.

See also `gets`

    # File ext/openssl/lib/openssl/buffering.rb, line 271
    def readlines(eol=$/)
      ary = []
      while line = self.gets(eol)
        ary << line
      end
      ary
    end

readpartial(maxlen, buf=nil) click to toggle source

Reads at most maxlen bytes from the stream. If buf is provided it must reference a string which will receive the data.

See `IO#readpartial` for full details.

    # File ext/openssl/lib/openssl/buffering.rb, line 146
    def readpartial(maxlen, buf=nil)
      if maxlen == 0
        if buf
          buf.clear
          return buf
        else
          return ""
        end
      end
      if @rbuffer.empty?
        begin
          return sysread(maxlen, buf)
        rescue Errno::EAGAIN
          retry
        end
      end
      ret = consume_rbuff(maxlen)
      if buf
        buf.replace(ret)
        ret = buf
      end
      ret
    end

ungetc(c) click to toggle source

Pushes character c back onto the stream such that a subsequent buffered character read will return it.

Unlike `IO#getc` multiple bytes may be pushed back onto the stream.

Has no effect on unbuffered reads (such as sysread).

    # File ext/openssl/lib/openssl/buffering.rb, line 323
    def ungetc(c)
      @rbuffer[0,0] = c.chr
    end

write(*s) click to toggle source

Writes s to the stream. If the argument is not a `String` it will be converted using `.to_s` method. Returns the number of bytes written.

    # File ext/openssl/lib/openssl/buffering.rb, line 369
    def write(*s)
      s.inject(0) do |written, str|
        do_write(str)
        written + str.bytesize
      end
    end

write_nonblock(s, exception: true) click to toggle source

Writes s in the non-blocking manner.

If there is buffered data, it is flushed first. This may block.

`write_nonblock` returns number of bytes written to the `SSL` connection.

When no data can be written without blocking it raises `OpenSSL::SSL::SSLError` extended by `IO::WaitReadable` or `IO::WaitWritable`.

`IO::WaitReadable` means `SSL` needs to read internally so `write_nonblock` should be called again after the underlying `IO` is readable.

`IO::WaitWritable` means `SSL` needs to write internally so `write_nonblock` should be called again after underlying `IO` is writable.

So `OpenSSL::Buffering#write_nonblock` needs two rescue clause as follows.

    # emulates blocking write.
    begin
      result = ssl.write_nonblock(str)
    rescue IO::WaitReadable
      IO.select([io])
      retry
    rescue IO::WaitWritable
      IO.select(nil, [io])
      retry
    end

Note that one reason that `write_nonblock` reads from the underlying `IO` is when the peer requests a new TLS/SSL handshake. See the openssl FAQ for more details. www.openssl.org/support/faq.html

By specifying a keyword argument exception to `false`, you can indicate that `write_nonblock` should not raise an IO::Wait*able exception, but return the symbol `:wait_writable` or `:wait_readable` instead.

    # File ext/openssl/lib/openssl/buffering.rb, line 413
    def write_nonblock(s, exception: true)
      flush
      syswrite_nonblock(s, exception: exception)
    end

### Private Instance Methods

consume_rbuff(size=nil) click to toggle source

Consumes size bytes from the buffer

    # File ext/openssl/lib/openssl/buffering.rb, line 91
    def consume_rbuff(size=nil)
      if @rbuffer.empty?
        nil
      else
        size = @rbuffer.size unless size
        ret = @rbuffer[0, size]
        @rbuffer[0, size] = ""
        ret
      end
    end

do_write(s) click to toggle source

Writes s to the buffer. When the buffer is full or `sync` is true the buffer is flushed to the underlying socket.

    # File ext/openssl/lib/openssl/buffering.rb, line 346
    def do_write(s)
      @wbuffer = Buffer.new unless defined? @wbuffer
      @wbuffer << s
      @wbuffer.force_encoding(Encoding::BINARY)
      @sync ||= false
      if @sync or @wbuffer.size > BLOCK_SIZE
        until @wbuffer.empty?
          begin
            nwrote = syswrite(@wbuffer)
          rescue Errno::EAGAIN
            retry
          end
          @wbuffer[0, nwrote] = ""
        end
      end
    end

fill_rbuff() click to toggle source

Fills the buffer from the underlying SSLSocket

    # File ext/openssl/lib/openssl/buffering.rb, line 78
    def fill_rbuff
      begin
        @rbuffer << self.sysread(BLOCK_SIZE)
      rescue Errno::EAGAIN
        retry
      rescue EOFError
        @eof = true
      end
    end