Here is a list of terms associated with power issues.
| Name | Definition |
| Fault | Momentary loss of power |
| Blackout | Prolonged power outage |
| Sag | Momentary low voltage |
| Brownout | Prolonged Low voltage |
| Spike | Momentary spike in voltage |
| Surge | Extended spike in voltage |
| Inrush | Initial voltage “surge” when a device is plugged in |
Here is a visual image.
You can use tar -tvf to show the contents of a tar file.
tar -tvf filename.tgz
You can extract a portion of the archive with
tar -zxvf filename.tgz path/inside/file -C destination/path
For instance, if I have a tar backup of my /home directory, and I need to extract a file out of the tarred Downloads to my current Downloads directory, I can do
tar -zxvf home.tgz home/incredigeek/Downloads/slack.deb ~/Downloads
https://www.cyberciti.biz/faq/list-the-contents-of-a-tar-or-targz-file/
https://stackoverflow.com/questions/24057301/bash-extract-only-part-of-tar-gz-archive
There are three types of law. Criminal, civil, and administrative.
| Type of Law | Examples | Standard of Proof | Burden of Proof | Penalty |
| Criminal Law | Murder, assault, robbery, arson | Beyond a reasonable doubt | Innocent until proven guilty | Fines, Jail, Prison, Death penalty |
| Civil Law | Property Disputes, Personal injury | Preponderance of evidence | Claimant must give proof (most cases) | Compensation for injuries/damage |
| Administrative Law | Define standards of performance and conduct for major industries, organizations and government agencies |
https://www.diffen.com/difference/Civil_Law_vs_Criminal_Law
The following is a list of “good to know” legislative acts.
| Acronym | Name | Notes |
| CFAA | Computer Fraud and Abuse Act | First major cyber crime legislation |
| Federal Sentencing Guidelines (1991) | Responsibility on senior management | |
| ECPA | Electronic Communications Privacy Act of 1986 | Made it a crime to invade the electronic privacy of an individual |
| CALEA | Comm Assistance for Law Enforcement Act of 1994 | Amended ECPA. Made wiretaps possible for law enforcement with a court order. |
| Economic Espionage Act of 1996 | Made theft no longer tied to something physical | |
| FISMA | Federal Information Security Management Act | Cyber security requirements for government agencies |
| DMCA | Digital Millennium Copyright Act | Copyright protection is 70 years + 1st major revision added CD/DVD protections |
| USA PATRIOT | USA PATRIOT Act of 2001 | Gave law enforcement and intelligence agencies broader wiretapping authorizations |
| Identity Theft and Assumption Deterrence Act (1998) | Made identity theft a crime. Up to 15 years in prison and $250,000 fine. | |
| HIPPA | Health Insurance Portability and Accountability Act (1996) | Regulations for security measures for hospitals, physicians, and insurance companies |
| HITEC | Health Information Technology for Economic and Clinical Health Act of 2009 | Amended HIPPA. Updated privacy/security requirements for Business Associates (BAs), requires a written contract known as a business associate agreement (BAA). BAs are directly subject to HIPPA and enforcement actions like a covered entity. HITECH also introduced new data breach notifications. |
| GLBA | Gramm-Leach-Bliley Act | Limits services that banks, lenders, and insurance agencies can provide and information they can share with each other |
| COPPA | Child Online Privacy Protection Act | Seeks to protects children (<13 years old) online |
| FERPA | Family Educational Rights and Privacy Act | Gives students certain privacy rights. Deals with adults >18, and Children in school <18 |
| ITAR | International Traffic in Arms Regulation | Regulates the export of military and defense related technologies |
| EAR | Export Administration Regulations | For commercial use, but may have military applications. |
| Name | Protection Length | |
| Trademarks | 10 Years | |
| Patents | 20 Years | |
| Copyright | 70 Years after the death of the author | |
| Trade Secrets | Until they are leaked. |
These steps assume you already have a public SSH key, if not, create one
SSH-Copy-Id is an easier way to upload ssh keys, however, it does not work on all devices.
ssh to the remote server using your password.
If it is not already created, create the authorized_keys file under the .ssh folder
touch ~/.ssh/authorized_keys chmod 600 ~/.ssh/authorized_keys vi ~/.ssh/authorized_keys
Add your public key to the end of the authorized_keys file
Ensure that the correct owner and permissions are on the files.
The .ssh directory should be
chmod 700 .ssh
And the authorized_keys file should be 600
chmod 600 ~/.ssh/authorized_keys
Both should be owned by the user. Change username to your username.
sudo chown -R username:username .ssh/authorized_keys
Helpful links
https://blog.tinned-software.net/setup-sftp-only-account-using-openssh-and-ssh-key/
https://blog.tinned-software.net/ssh-passwordless-login-with-ssh-key/
At the moment it does not look easily possible to install Armory Wallet on Fedora. Here are some notes about trying to get it to work.
The following person on Reddit was able to get it working on an older version of Fedora.
[Tutorial] Install Armory Wallet 0.96.4 on Fedora Workstation 29
byu/AmbitiousSpeed0 inBitcoin
The issue is that pyqt4 and pyqt4-devel are not available on the latest versions of Fedora.
The following prerequisites need to be installed
sudo dnf install git nano qt qt-devel python-devel libtool lmdb swig python-psutil
Other notes.
Armory relies on Bitcoin Core. You can install BitCoin core from https://bitcoincore.org. It will need to be fully synced which can take a long time “as in days/weeks”. Note that Armory will not work if you have the blockchain pruned. Which means you’ll need about 500GB of space for the BitCoin blockchain.
List of common symmetric encryption algorithms with their block and key size.
| Name | Block Size | Key Size | Notes |
| AES Advanced Encryption Standard | 128 | 128, 192, 256 | Is Rijndael |
| Rijndael | Variable | 128, 192, 256 | Is AES |
| Blowfish | 64 | 32-448 | Often used in SSH |
| DES Data Encryption Standard | 64 | 56 | |
| Triple DES | 64 | 112-168 | DES 3 times |
| IDEA | 64 | 128 | Used in PGP |
| RC4 Rivest Cipher 4 | Stream Cipher | 40-2048 | Insecure/Not used, used in WEP, WPA, and SSL |
| RC5 Rivest Cipher 5 | 32, 64, 128 | 0-2040 | |
| RC6 Rivest Cipher 6 | 128 | 128, 192, 256 | |
| Skipjack | 64 | 80 | Developed by the NSA and supported key escrow |
| CAST-128 | 64 | 40-128 | |
| CAST-256 | 128 | 128, 160, 192, 224, 256 | |
| Twofish | 128 | 1-256 | |
| ChaCha20 | Stream Cipher | 256 | |
Note that if you need to copy both your Private and Public key, you’ll need to export both separately.
You can list all the GPG keys with the following command.
gpg --list-keys
Change “keyID” to your key idea from the above command. The key ID is the long string of hexadecimal characters.
gpg --export-secret-keys "keyID" > private_key.asc
This will export the keys to private_key.asc. Rename as appropriate.
To export the Public Key
gpg --export "keyID" > public_key.asc
To use the key, you’ll need to import and trust the key.
gpg --allow-secret-key-import --import private_key.asc
gpg --edit-key "keyID"
Then type
trust
Select level 5.
Import the Public Key
gpg --import public_key.asc
To decrypt a single file do
gpg --batch --passphrase='password' ./file.gpg
If your GPG does not have a password, remove the whole `–passphrase=’password’` option
To decrypt multiple files you can run
for file in * ; do gpg --batch --passphrase='password' "$file" ; done
Typically you’ll need to reboot a server after an update if the Linux Kernel was updated. It is possible that services need to be restarted.
There is some good information here https://serverfault.com/questions/122178/how-can-i-check-from-the-command-line-if-a-reboot-is-required-on-rhel-or-centos
Install the needs-restarting utility
sudo dnf install -y yum-utils
Once installed, we can check if we need to reboot with
sudo needs-restarting -r
The -r option only reports if a reboot is required.
If we wanted to automatically check and reboot, we could do
sudo needs-restarting -r || sudo shutdown -r
We could alternatively just check the kernel version and if it is different, manually reboot the machine. Note that there could be a couple cases where the kernel didn’t update, but you still need a reboot, or services needed to be restarted View links below for more information.
LAST_KERNEL=$(rpm -q --last kernel | perl -pe 's/^kernel-(\S+).*/$1/' | head -1) CURRENT_KERNEL=$(uname -r) test $LAST_KERNEL = $CURRENT_KERNEL || shutdown -r
Quick and simple way to check the details on a fiber SFP on a Mikrotik router. Replace sfp1_name with the SFP name or leave out the name and select a number.
/interface ethernet monitor "sfp1_name"
Results
name: sfp1
status: link-ok
auto-negotiation: done
full-duplex: yes
tx-flow-control: no
rx-flow-control: no
advertising:
link-partner-advertising:
sfp-module-present: yes
sfp-rx-loss: no
sfp-type: SFP-or-SFP+
sfp-connector-type: LC
sfp-link-length-9um: 3000m
sfp-vendor-name: UBNT
sfp-vendor-part-number: UF-SM-1G-S
sfp-vendor-serial: FL31F80285729
sfp-manufacturing-date: 20-02-20
sfp-wavelength: 1550.32nm
sfp-temperature: 64C
sfp-supply-voltage: 3.23V
sfp-tx-bias-current: 30mA
sfp-tx-power: -5.254dBm
sfp-rx-power: -4.1dBm
eeprom-checksum: good
eeprom: 0000: 01 02 03 00 00 00 00 00 00 00 00 .....
Typically after a Linux Kernel update, you will want to reboot your machine to take advantage of the new kernel. But how do you know if you need to reboot?
Fortunately, there is a simple way to check.
cat /var/run/reboot-requiredIf it returns
*** System restart required ***
Then we should reboot the machine.
https://www.cyberciti.biz/faq/how-to-find-out-if-my-ubuntudebian-linux-server-needs-a-reboot/