Module: OpenSSL::Buffering

Includes:
Enumerable
Included in:
SSL::SSLSocket
Defined in:
lib/openssl/buffering.rb

Overview

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.

Defined Under Namespace

Classes: Buffer

Constant Summary collapse

BLOCK_SIZE =

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

1024*16

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#syncObject

The “sync mode” of the SSLSocket.

See IO#sync for full details.


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# File 'lib/openssl/buffering.rb', line 53

def sync
  @sync
end

Instance Method Details

#<<(s) ⇒ Object

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


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# File 'lib/openssl/buffering.rb', line 413

def <<(s)
  do_write(s)
  self
end

#closeObject

Closes the SSLSocket and flushes any unwritten data.


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# File 'lib/openssl/buffering.rb', line 474

def close
  flush rescue nil
  sysclose
end

#each(eol = $/) ⇒ Object Also known as: each_line

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

See also #gets


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# File 'lib/openssl/buffering.rb', line 250

def each(eol=$/)
  while line = self.gets(eol)
    yield line
  end
end

#each_byteObject

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


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# File 'lib/openssl/buffering.rb', line 291

def each_byte # :yields: byte
  while c = getc
    yield(c.ord)
  end
end

#eof?Boolean Also known as: eof

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

Returns:

  • (Boolean)

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# File 'lib/openssl/buffering.rb', line 322

def eof?
  fill_rbuff if !@eof && @rbuffer.empty?
  @eof && @rbuffer.empty?
end

#flushObject

Flushes buffered data to the SSLSocket.


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# File 'lib/openssl/buffering.rb', line 462

def flush
  osync = @sync
  @sync = true
  do_write ""
  return self
ensure
  @sync = osync
end

#getcObject

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


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# File 'lib/openssl/buffering.rb', line 284

def getc
  read(1)
end

#gets(eol = $/, limit = nil) ⇒ Object

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.


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# File '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

#initializeObject

Creates an instance of OpenSSL's buffering IO module.


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# File 'lib/openssl/buffering.rb', line 63

def initialize(*)
  super
  @eof = false
  @rbuffer = Buffer.new
  @sync = @io.sync
end

Writes args to the stream.

See IO#print for full details.


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# File '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) ⇒ Object

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

See Kernel#sprintf for format string details.


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# File 'lib/openssl/buffering.rb', line 454

def printf(s, *args)
  do_write(s % args)
  nil
end

#puts(*args) ⇒ Object

Writes args to the stream along with a record separator.

See IO#puts for full details.


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# File '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) ⇒ Object

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.


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# File '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) ⇒ Object

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.


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# File '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

#readcharObject

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

Raises:

  • (EOFError)

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# File 'lib/openssl/buffering.rb', line 301

def readchar
  raise EOFError if eof?
  getc
end

#readline(eol = $/) ⇒ Object

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

Raises EOFError if at end of file.

Raises:

  • (EOFError)

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# File 'lib/openssl/buffering.rb', line 275

def readline(eol=$/)
  raise EOFError if eof?
  gets(eol)
end

#readlines(eol = $/) ⇒ Object

Reads lines from the stream which are separated by eol.

See also #gets


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# File 'lib/openssl/buffering.rb', line 262

def readlines(eol=$/)
  ary = []
  while line = self.gets(eol)
    ary << line
  end
  ary
end

#readpartial(maxlen, buf = nil) ⇒ Object

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.


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# File '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) ⇒ Object

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).


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# File 'lib/openssl/buffering.rb', line 314

def ungetc(c)
  @rbuffer[0,0] = c.chr
end

#write(*s) ⇒ Object

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.


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# File '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) ⇒ Object

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.


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# File 'lib/openssl/buffering.rb', line 404

def write_nonblock(s, exception: true)
  flush
  syswrite_nonblock(s, exception: exception)
end