Hi Matt, On 06/02/2017 12:40 PM, Matt Caswell wrote: > > > On 02/06/17 11:00, Emeric Brun wrote: >> Hi, >> >> I'm working on an ASYNC engine designed to offload crypto on multiple thread >> for monoproc applications. >> >> No issue on asymetric crypto part but i'm facing a problem concerning >> ciphers: >> >> When an SSL_read operation perform a do_cipher decrypt: >> >> My engine defer the do_cipher to be processed by an other thread using the >> output buffer provided by to the do_cipher method. >> >> After that it performs an ASYNC_pause_job(). On the application side it >> results on a WANT_ASYNC error. >> >> The application consider that nothing was written on its output, and the >> buffer read buffer is reused for something else. >> >> SSL_read is called a second time after receiving the event on the async fd. >> But this time the app used a different buffer. >> >> On the engine side, i don't see any change on the do_cipher output buffer >> which would allow to manage the issue with a memcopy. >> >> So my question is: >> >> Is there a way to perform ciphering with an ASYNC engine when the app don't >> reuse the same buffer. > > No, the async operation is running in it own fibre which is initialised > on first call, so it is still using the arguments from that initial > call. Subsequent calls won't "see" any changes in those args. We should > probably be more explicit about that in the docs. > > Matt >
I see that you're using EVP_CIPH_FLAG_PIPELINE in the dasync engine and that you're calling do_cipher to write in pipe_ctx->outbufs[i]. I also know that intel's qat uses such interface. Where points these buffers? directly to the read buffer provided during the first SSL_read call or are they temporary allocated buffers copied into the read buffer passed during the second SSL_read call? R, Emeric -- openssl-dev mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-dev
