| /* |
| * Copyright (C) 2020 Square, Inc. and others. |
| * |
| * 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 okio |
| |
| import java.io.IOException |
| import javax.crypto.Cipher |
| |
| class CipherSource( |
| private val source: BufferedSource, |
| val cipher: Cipher |
| ) : Source { |
| private val blockSize = cipher.blockSize |
| private val buffer = Buffer() |
| private var final = false |
| private var closed = false |
| |
| init { |
| // Require block cipher |
| require(blockSize > 0) { "Block cipher required $cipher" } |
| } |
| |
| @Throws(IOException::class) |
| override fun read(sink: Buffer, byteCount: Long): Long { |
| require(byteCount >= 0L) { "byteCount < 0: $byteCount" } |
| check(!closed) { "closed" } |
| if (byteCount == 0L) return 0L |
| if (final) return buffer.read(sink, byteCount) |
| |
| refill() |
| |
| return buffer.read(sink, byteCount) |
| } |
| |
| private fun refill() { |
| while (buffer.size == 0L) { |
| if (source.exhausted()) { |
| final = true |
| doFinal() |
| break |
| } else { |
| update() |
| } |
| } |
| } |
| |
| private fun update() { |
| val head = source.buffer.head!! |
| var size = head.limit - head.pos |
| |
| // Shorten input until output is guaranteed to fit within a segment |
| var outputSize = cipher.getOutputSize(size) |
| while (outputSize > Segment.SIZE) { |
| check(size > blockSize) { "Unexpected output size $outputSize for input size $size" } |
| size -= blockSize |
| outputSize = cipher.getOutputSize(size) |
| } |
| val s = buffer.writableSegment(outputSize) |
| |
| val ciphered = |
| cipher.update(head.data, head.pos, size, s.data, s.pos) |
| |
| source.skip(size.toLong()) |
| |
| s.limit += ciphered |
| buffer.size += ciphered |
| |
| // We allocated a tail segment, but didn't end up needing it. Recycle! |
| if (s.pos == s.limit) { |
| buffer.head = s.pop() |
| SegmentPool.recycle(s) |
| } |
| } |
| |
| private fun doFinal() { |
| val outputSize = cipher.getOutputSize(0) |
| if (outputSize == 0) return |
| |
| // For block cipher, output size cannot exceed block size in doFinal. |
| val s = buffer.writableSegment(outputSize) |
| |
| val ciphered = cipher.doFinal(s.data, s.pos) |
| |
| s.limit += ciphered |
| buffer.size += ciphered |
| |
| // We allocated a tail segment, but didn't end up needing it. Recycle! |
| if (s.pos == s.limit) { |
| buffer.head = s.pop() |
| SegmentPool.recycle(s) |
| } |
| } |
| |
| override fun timeout() = source.timeout() |
| |
| @Throws(IOException::class) |
| override fun close() { |
| closed = true |
| source.close() |
| } |
| } |