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這次換 HP 裝 Spyware 啦~

討論的頗熱烈的,像是「HP is installing spyware on its machines disguised as an "analytics client"」、「HP stealthily installs new spyware called HP Touchpoint Analytics Client」。

這個軟體會被注意到是因為吃太多資源,而且使用者沒有同意安裝這個軟體 (目前看是起來是透過自動更新機制裝進去的):「Didn't Install HP TouchpointAnalyticsClient and It's Causing CPU 95-98 Red」(先備份一份在這邊,以免被砍...)。

然後這軟體很明顯會傳資料回 HP:

The HP Touchpoint Manager technology is now being delivered as a part of HP Device as a Service (DaaS) Analytics and Proactive Management capabilities. Therefore, HP is discontinuing the self-managed HP Touchpoint Manager solution.

先前聯想因為類似的行為賠了 350 萬美金,這次 HP 搞這包不知道會怎麼樣...

Savitech (盛微) 的 USB 音效驅動程式會安裝 Root CA (被發了 CVE-2017-9758)

Hacker News 上看到 CERT 的「Savitech USB audio drivers install a new root CA certificate」提到 Savitech USB audio driver 會安裝自己的 Root CA:

Savitech provides USB audio drivers for a number of specialized audio products. Some versions of the Savitech driver package silently install a root CA certificate into the Windows trusted root certificate store.

出自「Inaudible Subversion - Did your Hi-Fi just subvert your PC? (原網站已經無法訪問,參考備份連結 https://archive.is/K6REr)」,CVE 編號是 CVE-2017-9758,最初是由 n3kt0n 提出的:「某單位 drivers silently install certificate in trusted root certificate authorities store [CVE-2017-9758]」:

Mitre assigned this exposure the identifier CVE-2017-9758, but was initially tracked by HITCON ZeroDay project as ZD-2017-00386.

有兩把 CA public key 被塞進去。雖然目前還沒有徵兆 private key 有外洩,但還是建議儘快移除:

There is currently no evidence that the Savitech private key is compromised. However, users are encouraged to remove the certificate out of caution. The two known certificates are:

SaviAudio root certificate #1
‎Validity: Thursday, ‎May ‎31, ‎2012 - ‎Tuesday, ‎December ‎30, ‎2036
Serial number: 579885da6f791eb24de819bb2c0eeff0
Thumbprint: cb34ebad73791c1399cb62bda51c91072ac5b050

SaviAudio root certificate #2
Validity: ‎Thursday, ‎December ‎31, ‎2015 - ‎Tuesday, ‎December ‎30, ‎2036
Serial number: ‎972ed9bce72451bb4bd78bfc0d8b343c
Thumbprint: 23e50cd42214d6252d65052c2a1a591173daace5

另外 Savitech 也放出了新版的 driver,不包含 Root CA:

Savitech has released a new driver package to address the issue. Savitech drivers version 2.8.0.3 or later do not install the root CA certificate. Users still must remove any previously installed certificate manually.

看了一下說明,看起來是當時為了支援 Windows XP 而做的,但微軟已經不提供驅動程式的數位簽章了,所以就只好這樣搞...

用 4.5+ 的 Linux Kernel 限制 I/O 速度

在「Using cgroups to limit I/O」這邊看到作者試著用 cgroups 限制 I/O 速度。

作者前面花了不少篇幅解釋 cgroups v1 無法正確限制 I/O 速度,後面就在講 cgroups v2 怎麼做:

So, in order to limit I/O when this I/O may hit the writeback kernel cache, we need to use both memory and io controllers in the cgroups v2!

這會需要 4.5+ 的 kernel,可能會需要手動更新,或是直接使用比較新的 distribution:

Since kernel 4.5, the cgroups v2 implementation was marked non-experimental.

然後照抄就可以了 (不過這邊的指定都需要 root,作者用 $ 表示 shell 有點怪):

# mount -t cgroup2 nodev /cgroup2
# mkdir /cgroup2/cg2
# echo "+io" > /cgroup2/cgroup.subtree_control
# echo "8:0 wbps=1048576" > io.max
# echo $$ > /cgroup2/cg2/cgroup.procs

然後就可以跑 dd 測試速度了,同時間也可以跑 iostat 看。

Windows 將引入 TruePlay,推出作弊偵測的 API

在「Windows now includes gaming cheat detection at the system level」這邊看到微軟將會引入 TruePlay (然後跟 Sonostrueplay 衝名 XDDD) 作弊偵測機制。

很明顯的會有隱私問題,而也很明顯的微軟說不會有隱私問題:

As Microsoft notes, "to protect customer privacy, no data is shared or transmitted until permission is granted," and no information is sent until "processing has determined cheating is likely to have occurred."

這不是把人當傻子嗎,遊戲一開始就會要求你同意才能玩啊,所以資料一定會送出的啊... 而且 TruePlay 變成作業系統的標準配備後,作弊程式就會找 workaround 才會推出 :o

Android 將測試 DNS over TLS

從「Android getting "DNS over TLS" to prevent ISPs from knowing what websites you visit」這邊看到的報導,原
文在「Android getting “DNS over TLS” support to stop ISPs from knowing what websites you visit」這邊可以看到。

It appears that “DNS over TLS” support is being added to Android, according to several commits added to the Android Open Source Project (AOSP). The addition in the Android repository shows that a new setting will be added under Developer Options allowing users to turn on or off DNS over TLS. Presumably, if such an option is being added to Developer Options, then that means it is in testing and may arrive in a future version of Android such as version 8.1.

這邊用的應該是 RFC 7858 的「Specification for DNS over Transport Layer Security (TLS)」,已經是 Standards Track 了。預設使用 TCP port 853:

By default, a DNS client desiring privacy from DNS over TLS from a particular server MUST establish a TCP connection to port 853 on the server, unless it has mutual agreement with its server to use a port other than port 853 for DNS over TLS.

而且建議如果另外定義的話,不要用 port 53:

This recommendation against use of port 53 for DNS over TLS is to avoid complication in selecting use or non-use of TLS and to reduce risk of downgrade attacks.

另外也說明了在 port 853 上禁用明文傳輸:

DNS clients and servers MUST NOT use port 853 to transport cleartext DNS messages.

另外一個還在發展的標準是 Cisco 的人推出的「DNS over Datagram Transport Layer Security (DTLS)」,走的是 UDP port 853,不過看起來因為 stateless 的特性,需要考慮比較多問題... (尤其這類服務常配合 anycast)

不過即使將 DNS query 保護起來,TLS 本身還是會透漏 hostname 的部份 (因為 SNI 的關係),所以就 privacy 面向考量的話,沒有實質的意義... 主要還是考慮被竄改的問題?但如果是這樣的話,目前 TLS 連線本身就已經有這樣的保護了?暫時沒想到可以解什麼實際的問題...

在 Mac 上快速換輸入法的方法:Kawa

三月的時候在「在 Mac 上快速切換輸入法」這邊提到了 IMEShortcuts,但有時候還是不會生效...

在「GitHub 中那些不错的免费软件」這篇裡面提到了 open source 的 utatti/kawa 這個專案,裡面有針對 CJKV 輸入法的 bug 提供 workaround,就給個機會測試看看:

There is a known bug in the TIS library of macOS that switching keyboard layouts doesn't work well when done programmatically, especially between complex input sources like CJKV.

而且最近變得可以用 Homebrew 管理了,這樣之後升級比較方便。

Amazon Lightsail 支援 Windows 了

Amazon Lightsail 決定支援 Windows 了,算是其他目前幾家領頭的 VPS 還沒進入的領域:「Amazon Lightsail Update – Launch and Manage Windows Virtual Private Servers」。

由於多了 Windows 的授權費用,價錢貴了不少:

不過還是提供一個月免費的額度:

You can try out a 512 MB server for one month (up to 750 hours) at no charge.

不過不是所有 Amazon Lightsail 有開的區域都支援 Windows:

This feature is available today in the US East (Northern Virginia), US East (Ohio), US West (Oregon), EU (London), EU (Ireland), EU (Frankfurt), Asia Pacific (Singapore), Asia Pacific (Mumbai), Asia Pacific (Sydney), and Asia Pacific (Tokyo) Regions.

不過還是不知道 Amazon Lightsail 進入這塊市場的想法是什麼...

Linux 下 RAID1 的 SSD 會有讀取不平均問題

在「Unbalanced reads from SSDs in software RAID mirrors in Linux」這邊看到作者看 S.M.A.R.T. 數據時發現兩顆 SSD 硬碟組成的 RAID1 有很明顯的讀取不平均的問題:

242 Total_LBAs_Read [...] 16838224623
242 Total_LBAs_Read [...] 1698394290

原因是因為 Linux 對 RAID1 的 SSD 有不一樣的演算法:

The current state of RAID1 read balancing is kind of complex, but the important thing here in all kernels since 2012 is that if you have SSDs and at least one disk is idle, the first idle disk will be chosen.

2016 時演算法就更激進了,變成非 SSD 會:

In kernels with the late 2016 change, this widens to if at least one disk is idle, the first idle disk will be chosen, even if all mirrors are HDs.

加上 SSD 很快,這造成 loading 幾乎都在第一顆上... 這對 SSD 應該是還好啦 (理論上 SSD 的讀取不傷壽命),不過還是有點怪就是了。

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