本來以為是 bug，但實際測過後看起來像是 feature，但抓字串的方法很容易誤判，看起來是抓 welcome back 這組字串：
On further consideration I don't think it's a bug. I think Safari is assuming any page with "Welcome Back" on it is a login page and enabling this behaviour. Therefore I think it's intended.
然後作者也有找到 workaround，用 去閃偵測：
Nice one. I found that using a non-breaking space prevents the behaviour.
>p>welcome back</p>
其他人也有發現其他的字串也會中獎：
It seems the same applies to "Sign In"
"Log in" works too. I tried a couple other languages (Finnish, German, French, Chinese) but the issue/feature seems to only happen with English (although I did use Google Translate, so I can't guarantee I used the right idioms).
Several months ago I submitted what appeared to be a security flaw to CloudFalre’s bugbounty program. According to them, this is not a problem, it’s up to you to make up your own mind.
技術上就是透過 Cloudflare Workers 當作 proxy server，只是看起來 Cloudflare 對自家 IP 有特別處理，在設定妥當後，用 Cloudflare Workers 的 IP address 去連 Cloudflare 的站台，幾乎不會觸發 Cloudflare 的阻擋機制。
不過 free tier 還是有限制，主要就是數量：
The first 100,000 requests each day are free and paid plans start at just $5/10 million requests, making Workers as much as ten-times less expensive than other serverless platforms.
作者也有提到這點：
So let’s enjoy the 100 000 request/day for your free Cloudflare account and go scrape the world !
This was originally meant to be a side project that we'd work on every once in a while, but with all of the extra free time with the pandemic we each ended up putting a few hundred hours into it.
There were a total of 55 vulnerabilities discovered with 11 critical severity, 29 high severity, 13 medium severity, and 2 low severity reports. These severities were assessed by us for summarization purposes and are dependent on a mix of CVSS and our understanding of the business related impact.
I figured that since we were to replace that matrix function anyway, I could try replacing it with XMMatrixInverse being a “modern” replacement for D3DXMatrixInverse. XMMatrixInverse also uses SSE2 instructions so it should be equally optimal to the D3DX function, but I was nearly sure it would break the same way.
Here’s Intel versus AMD relative error of RCPPS instruction: http://const.me/tmp/vrcpps-errors-chart.png AMD is Ryzen 5 3600, Intel is Core i3 6157U.
Over the complete range of floats, AMD is more precise on average, 0.000078 versus 0.000095 relative error. However, Intel has 0.000300 maximum relative error, AMD 0.000315.
Both are well within the spec. The documentation says “maximum relative error for this approximation is less than 1.5*2^-12”, in human language that would be 3.6621E-4.
Source code that compares them by creating 16GB binary files with the complete range of floats: https://gist.github.com/Const-me/a6d36f70a3a77de00c61cf4f6c17c7ac
至於為什麼會生出 NaN 的原因，沒找出來還是有點可惜，不過這個解法還行，就是「新版的 library 既然沒問題，就大家也不要太計較舊版的問題」的概念...
Whether PostgreSQL’s repeatable-read behavior is correct therefore depends on one’s interpretation of the standard. It is surprising that a database based on snapshot isolation would reject the strict interpretation chosen by the seminal paper on SI, but on reflection, the behavior is defensible.
The execution of concurrent SQL-transactions at isolation level SERIALIZABLE is guaranteed to be serializable. A serializable execution is defined to be an execution of the operations of concurrently executing SQL-transactions that produces the same effect as some serial execution of those same SQL-transactions. A serial execution is one in which each SQL-transaction executes to completion before the next SQL-transaction begins.
The random number generator is compliant with security and cryptographic standards such as NIST SP 800-90A, FIPS 140-2, and ANSI X9.82.
不過畢竟這個指令不是常常被使用，一般使用者的影響應該是還好：
As explained in the earlier article, mitigating CrossTalk involves locking the entire memory bus before updating the staging buffer and unlocking it after the contents have been cleared. This locking and serialization now involved for those instructions is very brutal on the performance, but thankfully most real-world workloads shouldn't be making too much use of these instructions.
We disclosed an initial PoC (Proof-Of-Concept) showing the leakage of staging buffer content in September 2018, followed by a PoC implementing cross-core RDRAND/RDSEED leakage in July 2019. Following our reports, Intel acknowledged the vulnerabilities, rewarded CrossTalk with the Intel Bug Bounty (Side Channel) Program, and attributed the disclosure to our team with no other independent finders. Intel also requested an embargo until May 2020 (later extended), due to the difficulty of implementing a fix for the cross-core vulnerabilities identified in this paper.
問題是當一個 certificate request 包含了 N 個 domain 時，本來的 CAA 檢查應該要對這 N 個檢查，但程式寫成只會抓一個，然後檢查了 N 次：
The bug: when a certificate request contained N domain names that needed CAA rechecking, Boulder would pick one domain name and check it N times. What this means in practice is that if a subscriber validated a domain name at time X, and the CAA records for that domain at time X allowed Let’s Encrypt issuance, that subscriber would be able to issue a certificate containing that domain name until X+30 days, even if someone later installed CAA records on that domain name that prohibit issuance by Let’s Encrypt.
We confirmed the bug at 2020-02-29 03:08 UTC, and halted issuance at 03:10. We deployed a fix at 05:22 UTC and then re-enabled issuance.
Our preliminary investigation suggests the bug was introduced on 2019-07-25. We will conduct a more detailed investigation and provide a postmortem when it is complete.
Q: How many certificates are affected?
A: 2.6%. That is 3,048,289 currently-valid certificates are affected, out of ~116 million overall active Let’s Encrypt certificates. Of the affected certificates, about 1 million are duplicates of other affected certificates, in the sense of covering the same set of domain names.
For the last few months Chrome has been seeing many "impossible" crashes on Intel Gemini Lake, family 6 model 122 stepping 1 CPUs. These crashes only happen with 64-bit Chrome and only happen in the prologue of two functions. The crashes come and go across different Chrome versions.
