Golang Buffer.TrimSpace方法代码示例

// Like GosaDecrypt() but operates in-place on buf.
// Returns true if decryption successful and false if not.
// If false is returned, the buffer contents may be destroyed, but only
// if further decryption attempts with other keys would be pointless anyway,
// because of some fatal condition (such as the data not being a multiple of
// the cipher's block size).
func GosaDecryptBuffer(buf *bytes.Buffer, key string) bool {
	buf.TrimSpace()

	if buf.Len() < 11 {
		return false
	} // minimum length of unencrypted <xml></xml>

	data := buf.Bytes()
	if string(data[0:5]) == "<xml>" {
		return true
	}

	// Fixes the following:
	// * gosa-si bug in the following line:
	//     if( $client_answer =~ s/session_id=(\d+)$// ) {
	//   This leaves the "." before "session_id" which breaks base64
	// * new gosa-si protocol has ";IP:PORT" appended to message
	//   which also breaks base64
	for semicolon_period := 0; semicolon_period < len(data); semicolon_period++ {
		if data[semicolon_period] == ';' || data[semicolon_period] == '.' {
			buf.Trim(0, semicolon_period)
			data = buf.Bytes()
			break
		}
	}

	aescipher, _ := aes.NewCipher([]byte(util.Md5sum(key)))
	crypter := cipher.NewCBCDecrypter(aescipher, config.InitializationVector)

	cryptotest := make([]byte, (((3*aes.BlockSize)+2)/3)<<2)
	n := copy(cryptotest, data)
	cryptotest = cryptotest[0:n]
	cryptotest = util.Base64DecodeInPlace(cryptotest)
	n = (len(cryptotest) / aes.BlockSize) * aes.BlockSize
	cryptotest = cryptotest[0:n]
	crypter.CryptBlocks(cryptotest, cryptotest)
	if !strings.Contains(string(cryptotest), "<xml>") {
		return false
	}

	data = util.Base64DecodeInPlace(data)
	buf.Trim(0, len(data))
	data = buf.Bytes()

	if buf.Len()%aes.BlockSize != 0 {
		// this condition is fatal => further decryption attempts are pointless
		buf.Reset()
		return false
	}

	crypter = cipher.NewCBCDecrypter(aescipher, config.InitializationVector)
	crypter.CryptBlocks(data, data)

	buf.TrimSpace() // removes 0 padding, too

	return true
}

func faiConnection(conn *net.TCPConn) {
	defer conn.Close()
	var err error

	err = conn.SetKeepAlive(true)
	if err != nil {
		util.Log(0, "ERROR! SetKeepAlive: %v", err)
	}

	var buf bytes.Buffer
	defer buf.Reset()
	readbuf := make([]byte, 4096)
	n := 1
	for n != 0 {
		n, err = conn.Read(readbuf)
		if err != nil && err != io.EOF {
			util.Log(0, "ERROR! Read: %v", err)
		}
		if n == 0 && err == nil {
			util.Log(0, "ERROR! Read 0 bytes but no error reported")
		}

		// Find complete lines terminated by '\n' and process them.
		for start := 0; ; {
			eol := start
			for ; eol < n; eol++ {
				if readbuf[eol] == '\n' {
					break
				}
			}

			// no \n found, append to buf and continue reading
			if eol == n {
				buf.Write(readbuf[start:n])
				break
			}

			// append to rest of line to buffered contents
			buf.Write(readbuf[start:eol])
			start = eol + 1

			buf.TrimSpace()

			util.Log(2, "DEBUG! FAI monitor message from %v: %v", conn.RemoteAddr(), buf.String())
			buf.Reset()
		}
	}

	if buf.Len() != 0 {
		util.Log(2, "DEBUG! Incomplete FAI monitor message (i.e. not terminated by \"\\n\") from %v: %v", conn.RemoteAddr(), buf.String())
	}
}

//.........这里部分代码省略.........

	b.Reset()
	check(b.String(), "")
	check(b.Pointer(), nil)
	check(b.Capacity(), 0)
	check(b.Contains(""), true)
	check(b.Contains("a"), false)

	b.WriteString("Hallo")
	b.WriteByte(' ')
	b.Write([]byte{'d', 'i', 'e', 's'})
	b.WriteByte(' ')
	b.WriteString("ist ")
	b.WriteString("ein ")
	b.Write([]byte("Test"))
	check(b.String(), "Hallo dies ist ein Test")
	check(b.Contains("Hallo dies ist ein Test"), true)
	check(b.Contains("Test"), true)
	check(b.Contains("Hallo"), true)
	check(b.Contains("allo"), true)
	check(b.Contains(""), true)

	check(b.Split(" "), []string{"Hallo", "dies", "ist", "ein", "Test"})
	check(b.Split("X"), []string{"Hallo dies ist ein Test"})
	check(b.Split("Hallo dies ist ein Test"), []string{"", ""})
	check(b.Split("H"), []string{"", "allo dies ist ein Test"})
	check(b.Split("Test"), []string{"Hallo dies ist ein ", ""})
	check(b.Split("es"), []string{"Hallo di", " ist ein T", "t"})

	b.Reset()
	b.WriteString("  \n\t Hallo  \t\v\n")
	check(b.Len(), 15)
	p = b.Pointer()
	b.TrimSpace()
	check(b.String(), "Hallo")
	check(b.Len(), 5)
	check(b.Pointer(), p)

	b.Reset()
	b.WriteString("  \n\t   \t\v\n")
	check(b.Len(), 10)
	b.TrimSpace()
	check(b.Pointer(), nil)
	check(b.Len(), 0)
	check(b.Capacity(), 0)
	b.TrimSpace()
	check(b.Pointer(), nil)
	check(b.Len(), 0)
	check(b.Capacity(), 0)

	b.Reset()
	b.WriteString("  \n\t Hallo")
	check(b.Len(), 10)
	p = b.Pointer()
	b.TrimSpace()
	check(b.String(), "Hallo")
	check(b.Len(), 5)
	check(b.Pointer(), p)

	b.Reset()
	b.WriteString("Hallo  \t\v\n")
	check(b.Len(), 10)
	p = b.Pointer()
	b.TrimSpace()
	check(b.String(), "Hallo")
	check(b.Len(), 5)

// Handles one or more messages received over conn. Each message is a single
// line terminated by \n. The message may be encrypted as by security.GosaEncrypt().
func handle_request(tcpconn *net.TCPConn) {
	defer tcpconn.Close()
	defer atomic.AddInt32(&ActiveConnections, -1)

	//  defer util.Log(2, "DEBUG! Connection to %v closed", tcpconn.RemoteAddr())
	//  util.Log(2, "DEBUG! Connection from %v", tcpconn.RemoteAddr())

	var err error

	err = tcpconn.SetKeepAlive(true)
	if err != nil {
		util.Log(0, "ERROR! SetKeepAlive: %v", err)
	}

	var buf bytes.Buffer
	defer buf.Reset()
	readbuf := make([]byte, 4096)

	var conn net.Conn
	conn = tcpconn
	n := 1

	if config.TLSServerConfig != nil {
		// If TLS is required, we need to see a STARTTLS before the timeout.
		// If TLS is optional we need to accept idle connections for backwards compatibility
		if config.TLSRequired {
			conn.SetDeadline(time.Now().Add(config.TimeoutTLS))
		}

		for i := range starttls {
			n, err = conn.Read(readbuf[0:1])
			if n == 0 {
				if i != 0 { // Do not log an error for a port scan that just opens a connection and closes it immediately
					util.Log(0, "ERROR! Read error while looking for STARTTLS from %v: %v", conn.RemoteAddr(), err)
				}
				return
			}
			buf.Write(readbuf[0:1])
			if readbuf[0] == '\r' && starttls[i] == '\n' {
				// Read the \n that must follow \r (we don't support lone CR line endings)
				conn.Read(readbuf[0:1]) // ignore error. It will pop up again further down the line.
			}
			if readbuf[0] != starttls[i] {
				if config.TLSRequired {
					util.Log(0, "ERROR! No STARTTLS from %v, but TLS is required", conn.RemoteAddr())
					util.WriteAll(conn, []byte(message.ErrorReply("STARTTLS is required to connect")))
					return
				}
				break
			}
			if readbuf[0] == '\n' {
				buf.Reset() // purge STARTTLS\n from buffer
				conn = tls.Server(conn, config.TLSServerConfig)
			}
		}
	}

	context := security.ContextFor(conn)
	if context == nil {
		return
	}

	for n != 0 {
		//util.Log(2, "DEBUG! Receiving from %v", conn.RemoteAddr())
		n, err = conn.Read(readbuf)

		if err != nil && err != io.EOF {
			util.Log(0, "ERROR! Read: %v", err)
		}
		if err == io.EOF {
			util.Log(2, "DEBUG! Connection closed by %v", conn.RemoteAddr())
		}
		if n == 0 && err == nil {
			util.Log(0, "ERROR! Read 0 bytes but no error reported")
		}

		// Find complete lines terminated by '\n' and process them.
		for start := 0; ; {
			eol := start
			for ; eol < n; eol++ {
				if readbuf[eol] == '\n' {
					break
				}
			}

			// no \n found, append to buf and continue reading
			if eol == n {
				buf.Write(readbuf[start:n])
				break
			}

			// append to rest of line to buffered contents
			buf.Write(readbuf[start:eol])
			start = eol + 1

			buf.TrimSpace()

			// process the message and get a reply (if applicable)
//.........这里部分代码省略.........