okhttp3.internal.ws.WebSocketProtocol.kt Maven / Gradle / Ivy
/*
* Copyright (C) 2014 Square, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package okhttp3.internal.ws
import okio.Buffer
import okio.ByteString.Companion.encodeUtf8
object WebSocketProtocol {
/** Magic value which must be appended to the key in a response header. */
internal const val ACCEPT_MAGIC = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
/*
Each frame starts with two bytes of data.
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-------+ +-+-------------+
|F|R|R|R| OP | |M| LENGTH |
|I|S|S|S| CODE | |A| |
|N|V|V|V| | |S| |
| |1|2|3| | |K| |
+-+-+-+-+-------+ +-+-------------+
*/
/** Byte 0 flag for whether this is the final fragment in a message. */
internal const val B0_FLAG_FIN = 128
/** Byte 0 reserved flag 1. Must be 0 unless negotiated otherwise. */
internal const val B0_FLAG_RSV1 = 64
/** Byte 0 reserved flag 2. Must be 0 unless negotiated otherwise. */
internal const val B0_FLAG_RSV2 = 32
/** Byte 0 reserved flag 3. Must be 0 unless negotiated otherwise. */
internal const val B0_FLAG_RSV3 = 16
/** Byte 0 mask for the frame opcode. */
internal const val B0_MASK_OPCODE = 15
/** Flag in the opcode which indicates a control frame. */
internal const val OPCODE_FLAG_CONTROL = 8
/**
* Byte 1 flag for whether the payload data is masked.
*
* If this flag is set, the next four
* bytes represent the mask key. These bytes appear after any additional bytes specified by [B1_MASK_LENGTH].
*/
internal const val B1_FLAG_MASK = 128
/**
* Byte 1 mask for the payload length.
*
* If this value is [PAYLOAD_SHORT], the next two
* bytes represent the length. If this value is [PAYLOAD_LONG], the next eight bytes
* represent the length.
*/
internal const val B1_MASK_LENGTH = 127
internal const val OPCODE_CONTINUATION = 0x0
internal const val OPCODE_TEXT = 0x1
internal const val OPCODE_BINARY = 0x2
internal const val OPCODE_CONTROL_CLOSE = 0x8
internal const val OPCODE_CONTROL_PING = 0x9
internal const val OPCODE_CONTROL_PONG = 0xa
/**
* Maximum length of frame payload. Larger payloads, if supported by the frame type, can use the
* special values [PAYLOAD_SHORT] or [PAYLOAD_LONG].
*/
internal const val PAYLOAD_BYTE_MAX = 125L
/** Maximum length of close message in bytes. */
internal const val CLOSE_MESSAGE_MAX = PAYLOAD_BYTE_MAX - 2
/**
* Value for [B1_MASK_LENGTH] which indicates the next two bytes are the unsigned length.
*/
internal const val PAYLOAD_SHORT = 126
/** Maximum length of a frame payload to be denoted as [PAYLOAD_SHORT]. */
internal const val PAYLOAD_SHORT_MAX = 0xffffL
/**
* Value for [B1_MASK_LENGTH] which indicates the next eight bytes are the unsigned
* length.
*/
internal const val PAYLOAD_LONG = 127
/** Used when an unchecked exception was thrown in a listener. */
internal const val CLOSE_CLIENT_GOING_AWAY = 1001
/** Used when an empty close frame was received (i.e., without a status code). */
internal const val CLOSE_NO_STATUS_CODE = 1005
fun toggleMask(cursor: Buffer.UnsafeCursor, key: ByteArray) {
var keyIndex = 0
val keyLength = key.size
do {
val buffer = cursor.data
var i = cursor.start
val end = cursor.end
if (buffer != null) {
while (i < end) {
keyIndex %= keyLength // Reassign to prevent overflow breaking counter.
// Byte xor is experimental in Kotlin so we coerce bytes to int, xor them
// and convert back to byte.
val bufferInt: Int = buffer[i].toInt()
val keyInt: Int = key[keyIndex].toInt()
buffer[i] = (bufferInt xor keyInt).toByte()
i++
keyIndex++
}
}
} while (cursor.next() != -1)
}
fun closeCodeExceptionMessage(code: Int): String? {
return if (code < 1000 || code >= 5000) {
"Code must be in range [1000,5000): $code"
} else if (code in 1004..1006 || code in 1015..2999) {
"Code $code is reserved and may not be used."
} else {
null
}
}
fun validateCloseCode(code: Int) {
val message = closeCodeExceptionMessage(code)
require(message == null) { message!! }
}
fun acceptHeader(key: String): String {
return (key + ACCEPT_MAGIC).encodeUtf8().sha1().base64()
}
}