Calculation of the HMAC – Information Security Stack Exchange

I tried to learn how to calculate HMAC, but I seem to be missing something. According to this wiki page, the call to HMAC SHA1 should have the value of an empty key and a message fbdb1d1b18aa6c08324b7d64b71fb76370690e1d,

I confirmed it with:

$ echo -n "" | openssl dgst -sha1 -hmac ""

(stdin) = fbdb1d1b18aa6c08324b7d64b71fb76370690e1d

After the pseudocode in the wiki page, I tried to do this in Bash:

ipad = $ (printf & # 39;  36% .0s & # 39; {1..64})

opad = $ (printf & # 39;  x5C% .0s & # 39; {1..64})

echo -n $ opad $ (echo -n $ ipad | sha1sum | awk # {print $ 1} & # 39;) | sha1sum

I thought since the key is empty, the inner padded key will only be 64 bytes in size x36 Signs and x5C for the outer padded key. And since the message is empty, HMAC can be calculated over SHA1 (o_key_pad || SHA1 (i_key_pad)), However, there is another result. What do I miss?

Terminology – term for helpful information in a form

I am writing a suggestion and have been surprised at the description for this element:

Enter the image description here

The informative text (in pink) under a field serves to give a reason for the required data, thereby answering the uncertainty of the users why they need to fill in this field.

The information behind the "i" symbol clearly indicates that you need to be x years old to register so that it is not duplicate information.

Is there a specific term for this type of element within a form?

More information >> | Black Hat Seo & Affiliate Marketing Forum

Here is the place Trialix can be useful in the end. It can grow the constituents of Nitric Oxide to improve blood circulation and help you achieve more eager and grounded erections. This could strengthen the blood-holding point of the penile chambers, so you can stay longer in sexual intercourse.

Information Architecture – 8 short tutorial videos: all embedded in one page vs. separate pages with title link?

In terms of efficiency you are right. It would be preferable to show them all on one page. It allows a single click to get to each video, and it does not take fiddling to figure out which video was the one I should leave and come back later. They can be browsed to show all items with minimal effort.

Performance is a legitimate concern, but if you test, I do not think it will be as bad as you might expect. The simple solution to the performance problem is to load the videos as needed and load them only when clicked. The good thing is that Youtube (and possibly other video services) did this for you. If you delete an embedded YouTube video, it will not load indeed Video until you click on it so that the user does not download all 8 videos when the page loads. There is a slight performance hit on one hand, but it's negligible compared to the time it would take to navigate on multiple pages (not to mention that you still need to load the pages and all the trouble when clicking).

do not forget that Slow interactions are just as bad as slow performance. If you force that user to be slow instead of the system, that's about at least so bad, if not worse, Anecdotally I annoy me in locations that are slow use (long useless animations, intros, delayed response) compared to websites that are just too slow burden,

Do not forget to test the actual page load time … I guess it will not be as bad as you think. And do not just load all the videos at once, play first, then the second, and so on, just as a normal user would. I really doubt that you will see a performance hit that is so bad that it is worth it interaction painful.

Firewalls – Country Blocking – Exchange of information security stacks

By filtering the IP ranges of entire countries, the malicious traffic of the actors in these countries is significantly reduced. but it will be almost 100% COMPLETED block legal users from these countries.

While this is a sensible approach to dealing with automated scans, it does not do anything against a human attacker who just ignores traffic over a VPN.

IP blocking is best for time-critical operations, such as Defense against sudden malicious traffic outside an IP range. Since it is easy to overcome, it is not a real "defense"; It is merely a roadblock that should temporarily obstruct, deter or annoy.

Android TV Disables the display of audio and video information on the HDMI input when the resolution changes

I have a Sharp LC50UA6800X with Android 8.0.0.

When playing games on a PS4 Pro, the info pop-up will be displayed in the top left corner of the game during the game. B .:
HDMI input 1
Audio: LPCM
Video: 2160p 60Hz HDR

I suspect that the PS4 Pro will dynamically change the resolution, causing the TV to report a change.

This information is distracting and takes up a lot of space. Is this even available to turn it off?

AWS SSM Agent Protection – Information Security Stack Exchange

Our company has recently switched to the AWS cloud, and AWS relies heavily on the SSM agent, it's also open source. (Https://

As I understand it, this agent is not signed when you deploy it on your computer. Cloudwatch / runcommand depends on this utility on the host.

When an attacker compiles his own SSM agent and pings the AWS server as usual. It seems he could fly under the radar and do evil things without raising the alarm.

Attack scenario:

  1. Get access to the box,
  2. kill the original agent,
  3. start my evil agent
  4. Start my bitcoin mining script.

Are there ways to protect the agent?

Malware – BadBIOS Reflashes – Information Security Stack Exchange

Did he really claim that even if you unsolder the chip from the motherboard and connect it to an SPI programmer that is not BadBIOS, you can not read or read the actual badBIOS image again?

The claim fully referred to here was:

We've already found some permanent BIOS malware that can survive flashing again.


This is short enough to be interpreted a bit, but Vafa's interpretation seems to be consistent with Dragos Ruiu's original wording and other claims.

In theory, is it even possible for a chip to "fool" you about the actual content when it is not connected to the host motherboard?

No serial flash chip of the type normally used for BIOS storage, no. These parts are for storage only – they contain nothing that is recognizable as a CPU, and can not be reconfigured as implied here.

More complex storage devices (like SSDs) could lead to it theoretically be reconfigured to hide data in the empty memory area, but this is not such a device.