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 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 openssl/lib/openssl/buffering.rb, line 413
def <<(s)
  do_write(s)
  self
end

close() click to toggle source

Closes the SSLSocket and flushes any unwritten data.

# File openssl/lib/openssl/buffering.rb, line 474
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 openssl/lib/openssl/buffering.rb, line 250
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 openssl/lib/openssl/buffering.rb, line 291
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 openssl/lib/openssl/buffering.rb, line 322
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 openssl/lib/openssl/buffering.rb, line 462
def flush
  osync = @sync
  @sync = true
  do_write ""
  return self
ensure
  @sync = osync
end

getc() click to toggle source

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

# File openssl/lib/openssl/buffering.rb, line 284
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 openssl/lib/openssl/buffering.rb, line 226
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 openssl/lib/openssl/buffering.rb, line 441
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 openssl/lib/openssl/buffering.rb, line 454
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 openssl/lib/openssl/buffering.rb, line 423
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 openssl/lib/openssl/buffering.rb, line 110
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 openssl/lib/openssl/buffering.rb, line 195
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 openssl/lib/openssl/buffering.rb, line 301
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 openssl/lib/openssl/buffering.rb, line 275
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 openssl/lib/openssl/buffering.rb, line 262
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 openssl/lib/openssl/buffering.rb, line 137
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 openssl/lib/openssl/buffering.rb, line 314
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 openssl/lib/openssl/buffering.rb, line 360
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 openssl/lib/openssl/buffering.rb, line 404
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 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 openssl/lib/openssl/buffering.rb, line 337
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 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