Histria. Dave Hyatt, Joe Hewitt e Blake Ross, que deram incio ao projeto Firefox, diziam acreditar que a utilidade do navegador Mozilla estava comprometida com os.The Mozilla Firefox project was created by Dave Hyatt and Blake Ross as an experimental branch of the Mozilla browser.Firefox 1. No Limits Roller Coaster Free Full Download more. November 9, 2004.Mozilla Security Blog.AES GCM is a NIST standardised authenticated encryption algorithm FIPS 8.D.Since its standardisation in 2.TLS.With 8. 8 it is by far the most widely used TLS cipher in Firefox.Firefox telemetry on symmetric ciphers in TLSUnfortunately the AES GCM implementation used in Firefox provided by NSS until now did not take advantage of full hardware acceleration on all platforms it used a slower software only implementation on Mac, Linux 3.AVX, PCLMUL, and AES NI hardware instructions.Based on hardware telemetry information, only 3.Firefox 5.In this post I describe how I made AES GCM in NSS and thus Firefox 5.To evaluate the actual impact on Firefox users, I tested the practical speed of our encryption by downloading a large file from a secure site using various hardware configurations Downloading a file on a mid 2.Mac.Book Pro Retina with Firefox 5.UtiluMFC/img/utilumfc_specify_which_versions.png' alt='Mozilla Firefox 9.0 Final' title='Mozilla Firefox 9.0 Final' />Flock, the best team communication app and online collaboration platform, comes with team messaging, project management and other great features that improve.CPU usage in ssl.AESGCM, the routine that performs the decryption.On a Windows laptop with an AMD C 7.AES NI instruction Firefox CPU usage is 6.MBs.This doesnt seem to be only an academic issue Particularly for battery operated devices, the energy consumption difference would be noticeable.Mozilla Firefox 9.0 Final' title='Mozilla Firefox 9.0 Final' />Improving GCM performance.Speeding up the GCM multiplication function is the first obvious step to improve AES GCM performance.A bug was opened on integration of the original AES GCM code to provide an alternative to the textbook implementation of gcmHash.Mult.This code is not only slow but has timing side channels as you can see in the following excerpt from the binary multiplication algorithm for ib 1 ib lt bused ib.Inner product Digits of a.MPDIGITSa, aused, bi, MPDIGITSc ib.MPDIGITc, ib aused bi.We can improve on two fronts here.First NSS should use the PCLMUL hardware instruction to speed up the ghash multiplication if possible.Second if PCLMUL is not available, NSS should use a fast constant time implementation.Bug 8.Unfortunately the fastest code that was proposed uses table lookups and is therefore not constant time accessing memory locations in the same cache line still leaks timing information.Thanks to Thomas Pornin I re implemented the binary multiplication in a way that doesnt leak any timing information and is still faster than any other proposed C code see Bug 8.Check out Thomas excellent write up for details.If PCLMUL is available on the CPU, using it is the way to go.All modern compilers support intrinsics, which allow us to write inline assembly in C that runs on all platforms without having to write assembly code files.A hardware accelerated implementation of the ghash multiplication can be easily implemented with mmclmulepi.On Mac and Linux the new 3.PCLMUL or AVX is not available.Since Windows doesnt support 1.NSS falls back to the slower 3.Improving AES performance.Bodybuilding Schedule For Beginners Pdf Download .To speed up AES, NSS requires hardware acceleration on Mac as well as on Linux 3.AVX or has it disabled.When NSS cant use the specialised AES code it falls back to a table based implementation that is again not constant time in addition to being slow.There are currently no plans of rewriting the existing fallback code.AES is impossible to implement efficiently in software without introducing side channels.Implementing AES with intrinsics on the other hand is a breeze.Schedule0.Nr i.Schedulei. m mmaesenclastsi.Schedulecx Nr.Key expansion is a little bit more involved for 1.Mac sees the biggest improvement here.Previously, only Windows and 6.Linux used AES NI, and now all desktop x.Looking at the numbers.To measure the performance gain of the new AES GCM code I encrypted a 4.MB file with a 1.AES GCM.Note that these numbers are supposed to show a trend and heavily depend on the used machine and system load at the time.Linux measurements are done on an Intel Core i.Windows measurements on a Surface Pro 2 with an Intel Core i.U, and Mac mid 2.Core i.HQ.For all following graphs lower is better.Linux 6.AES GCM 1.Linux 3.AES GCM 1.Performance of AES GCM 1.Linux machine without hardware support for the AES, PCLMUL, or AVX instructions is at least twice as fast now.If the AES and PCLMUL instructions are available, the new code only needs 3.The speed up for 3.Linux is more significant as it didnt previously have any hardware accelerated code.With full hardware acceleration the new code is more than 5 times faster than before.Even in the worst case when PCLMUL is not available the speedup is still more than 5.The story is similar on Windows, although NSS already had fast code for 3.Windows users.Windows 6.AES GCM 1.Windows 3. 2 AES GCM 1.Performance improvements on Mac 6.AES NI or PCLMUL is not available.Mac OSX AES GCM 1.The numbers in Firefox.NSS 3.Firefox 5.AES GCM code.It provides significantly reduced CPU usage for most TLS connections or higher download rates meaning better energy efficiency, too.NSS 3.CPUs capabilities and using hardware acceleration whenever possible.Assuming that all intrinsics and mathematical operations other than division are constant time on the CPU, the new code doesnt have any timing side channels.On the very basic laptop with the AMD C 7.MBs to 6.MBs, and this is a device that has no hardware acceleration support.To see the performance improvement we can look at the case where AVX is not available which is the case for about 23 of the Firefox population.Assuming that at least AES NI and PCLMUL is supported by the CPU we see the CPU usage drop from 1.AESDecrypt CPU usage with NSS 3.AVX hardware support.AESDecrypt CPU usage with NSS 3.AVX hardware support.The most immediate effect can be seen on Mac.AESDecrypt NSS 3.CPU while in NSS 3.AESDecrypt CPU usage with NSS 3.Mac OSXAESDecrypt CPU usage with NSS 3.Mac OSXThe most significant performance improvements are summarise din the following table depicting the time in seconds to decrypt a 5.MB file with AES GCM 1.Linux 3.Mac.No AVX support.NSS 3.Firefox 5. 52.
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