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 40
def initialize(*)
  super
  @eof = false
  @rbuffer = ""
  @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 String#to_s.

# File ext/openssl/lib/openssl/buffering.rb, line 386
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 449
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 224
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 265
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 296
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 437
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 ext/openssl/lib/openssl/buffering.rb, line 258
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 200
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 416
def print(*args)
  s = ""
  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 429
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 396
def puts(*args)
  s = ""
  if args.empty?
    s << "\n"
  end
  args.each{|arg|
    s << arg.to_s
    if $/ && /\n\z/ !~ s
      s << "\n"
    end
  }
  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 87
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

# File ext/openssl/lib/openssl/buffering.rb, line 168
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
  raise EOFError if ret.empty?
  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 275
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 249
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 236
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 114
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
  raise EOFError if ret.empty?
  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 288
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 String#to_s. Returns the number of bytes written.

# File ext/openssl/lib/openssl/buffering.rb, line 339
def write(s)
  do_write(s)
  s.bytesize
end

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

Writes str 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

# File ext/openssl/lib/openssl/buffering.rb, line 377
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 68
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 311
def do_write(s)
  @wbuffer = "" unless defined? @wbuffer
  @wbuffer << s
  @wbuffer.force_encoding(Encoding::BINARY)
  @sync ||= false
  if @sync or @wbuffer.size > BLOCK_SIZE or idx = @wbuffer.rindex($/)
    remain = idx ? idx + $/.size : @wbuffer.length
    nwritten = 0
    while remain > 0
      str = @wbuffer[nwritten,remain]
      begin
        nwrote = syswrite(str)
      rescue Errno::EAGAIN
        retry
      end
      remain -= nwrote
      nwritten += nwrote
    end
    @wbuffer[0,nwritten] = ""
  end
end

fill_rbuff() click to toggle source

Fills the buffer from the underlying SSLSocket

# File ext/openssl/lib/openssl/buffering.rb, line 55
def fill_rbuff
  begin
    @rbuffer << self.sysread(BLOCK_SIZE)
  rescue Errno::EAGAIN
    retry
  rescue EOFError
    @eof = true
  end
end