> This patch modifies `CipherOutputStream` to avoid pointless memory > allocations when decrypting data using AEAD ciphers. This is related to > #11597, which fixed a similar issue in `CipherInputStream`. > > `Cipher.update` does not output any data when doing AEAD decryption; all data > is buffered, and is later returned in one shot from `doFinal`. > `Cipher.getOutputSize` returns the buffer size required by `doFinal`, which > increases after every `update`, triggering new allocation in `ensureCapacity`. > > This patch addresses the issue by calling the `update` overload that returns > the output buffer until one of the update calls returns some data. When that > happens, we know that the cipher does not buffer everything until `doFinal`, > and revert to original behavior. > > This PR adds a new benchmark for AES/GCM encryption and decryption using > `CipherOutputStream`. > > Benchmark results before: > > Benchmark (dataSize) (keyLength) (provider) Mode > Cnt Score Error Units > AESGCMCipherOutputStream.decrypt 16384 128 thrpt > 40 27949,624 ± 301,408 ops/s > AESGCMCipherOutputStream.decrypt 1048576 128 thrpt > 40 20,730 ± 0,875 ops/s > AESGCMCipherOutputStream.encrypt 16384 128 thrpt > 40 175358,641 ± 4235,808 ops/s > AESGCMCipherOutputStream.encrypt 1048576 128 thrpt > 40 2588,111 ± 35,469 ops/s > > > after: > > Benchmark (dataSize) (keyLength) (provider) Mode > Cnt Score Error Units > AESGCMCipherOutputStream.decrypt 16384 128 thrpt > 40 69644,217 ± 1081,032 ops/s > AESGCMCipherOutputStream.decrypt 1048576 128 thrpt > 40 949,667 ± 9,431 ops/s > AESGCMCipherOutputStream.encrypt 16384 128 thrpt > 40 173144,038 ± 3279,149 ops/s > AESGCMCipherOutputStream.encrypt 1048576 128 thrpt > 40 2514,840 ± 87,935 ops/s
Daniel Jeliński has updated the pull request incrementally with one additional commit since the last revision: improve wording ------------- Changes: - all: https://git.openjdk.org/jdk/pull/11693/files - new: https://git.openjdk.org/jdk/pull/11693/files/7b295132..1b7a16b1 Webrevs: - full: https://webrevs.openjdk.org/?repo=jdk&pr=11693&range=02 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11693&range=01-02 Stats: 7 lines in 2 files changed: 2 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/11693.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11693/head:pull/11693 PR: https://git.openjdk.org/jdk/pull/11693
