Computer Tips - Programming, Cybersecurity and Tech Tutorials

Follow these steps to share a folder from your host macOS to guest Kali Linux running inside VirtualBox. Step 1: From your macOS, Go to "System Preferences... >> Sharing" Step 2: Enable the File Sharing option and add a folder to share Step 3: Open VirtualBox >> Select Kali Linux (or any other image) Step 4: Click on "Settings >> Share Folder" Step 5: Click on Add new shared folder button and add the same folder you previously added in macOS from Step 2 Step 6: Log in to your Kali Linux image Step 7: Open Terminal and type the command "sudo adduser $USER vboxsf" Step 8: Reboot Kali Linux

Error: vb_perf.cpp: In function ‘int main(int, const char**)’: vb_perf.cpp:63:23: error: variable ‘main(int, const char**)::rusage rusage’ has initializer but incomplete type    63 |         struct rusage rusage = { };       |                       ^~~~~~ vb_perf.cpp:64:19: error: ‘RUSAGE_SELF’ was not declared in this scope    64 |         getrusage(RUSAGE_SELF, &rusage);       |                   ^~~~~~~~~~~ vb_perf.cpp:64:9: error: ‘getrusage’ was not declared in this scope; did you mean ‘rusage’?    64 |         getrusage(RUSAGE_SELF, &rusage);       |         ^~~~~~~~~       |         rusage Solution: Include this header to your source code: #include <...

 Crypto++ is a popular C++ library for cryptography. Instruction in this article can be used to install Cryptopp for all operating systems similar to Kali Linux. Check out this article if you want to use it with Xcode in macOS. Step 1: Download Crypto++ using this link Step 2: Extract Crypto++ and switch to that directory from the terminal or shell. Step 3: $ make Step 4: $ make test Step 5: $ sudo make install Step 6: Compile your program using g++ -I/usr/local/include -L/usr/local/lib yourCode.cpp -lcryptopp

This tutorial demonstrates the use of Google Workspace apps to automate the onboarding experience for new users by adding them to a google group and sending automated welcome emails after they are added. Step 1: Log in to Google Drive using your Google Workspace account and create a new Google Sheet. Step 2: Go to Insert > Form and create a new Google Form. Step 3: Add the email address and google group fields. Step 4: Go to Tools > Script editor. Step 5: In Apps Script > Go to Project Settings > Check the box for "Show "appsscript.json" manifest file in editor" option. Step 6: Go to Editor > appsscript.json and change it to the following:

This tutorial demonstrates how to automate the user creation process in Google workspace using Admin SDK. Step 1: Log in to Google Drive using your Google Workspace account and create a new Google Sheet. Step 2: Go to Insert > Form and create a new Google Form. Step 3: Add the desired fields: First Name, Last Name, Recovery Email, Recovery Phone, Reporting Manager, Location, Title, Department, etc. Step 4: Go to Tools > Script editor. Step 5: In Apps Script > Go to Project Settings > Check the box for "Show "appsscript.json" manifest file in editor" option. Step 6: Go to Editor > appsscript.json and change it to the following:

In this tutorial, I will walk you through redirecting a URL in WordPress without using any plugins. You can open a Terminal or Command Prompt window and do the following: $cd to /var/www/html $ls -loa $sudo nano .htaccess Append to the end of file “Redirect 301 old-URL new-URL” Save the file and exit $sudo service apache2 restart This tutorial redirects a URL in WordPress without a plugin by adding a Redirect 301 rule to the site's .htaccess file on an Apache server. A 301 tells browsers and search engines that the move is permanent. Editing .htaccess directly is lightweight and avoids extra plugins, but keep a backup, since a syntax mistake there can take the site down until it is corrected.

In this tutorial, I will share strategies to generate random keys and initialization vector in C++ using CryptoPP library. Approach 1: SecByteBlock key(32), iv(24); AutoSeededRandomPool prng; prng.GenerateBlock(key, key.size()); prng.GenerateBlock(iv, iv.size()); Approach 2: SecByteBlock key(16), iv(16); std::string password = "Super secret password"; DeriveKeyAndIV(password, "encryption example", 100, key, key.size(), iv, iv.size());

 I run into issues every time I update my VirtualBox version on my MacBook Pro. If you run into issues where you can't start a VM instance, try this fix. Open Virtualbox >> Go to your VM image >> Click on Settings >> Go to Audio >> Uncheck the "Enable Audio" box. This fixes VirtualBox VMs that crash or abort on macOS after an update, a recurring annoyance. The workaround is to disable audio for the affected VM in its settings. The audio backend is a common source of these crashes on macOS, so turning it off lets the VM start while leaving the rest of its configuration untouched.

Error code: $ sudo cat /var/log/syslog | grep "tree" Binary file (standard input) matches Solution: $ sudo cat /var/log/syslog | grep "tree" --text Jul 14 17:43:00 osboxes kernel: [    3.042582] vboxguest: loading out-of-tree module taints kernel. Jul 15 13:24:47 osboxes kernel: [    3.420002] vboxguest: loading out-of-tree module taints kernel. Jul 15 13:54:22 osboxes kernel: [    3.027623] vboxguest: loading out-of-tree module taints kernel. Sep 28 12:59:21 osboxes kernel: [    3.165531] vboxguest: loading out-of-tree module taints kernel. Sep 28 13:46:04 osboxes kernel: [    2.755048] vboxguest: loading out-of-tree module taints kernel. Sep 28 13:51:08 osboxes kernel: [    3.508174] vboxguest: loading out-of-tree module taints kernel. Oct 19 21:04:41 osboxes kernel: [    2.762903] vboxguest: loading out-of-tree module taints kernel. Oct 19 21:11:51 osboxes kernel: [    2.566860] vboxguest: loading out-of-...

If you are facing errors like " 'cryptopp/aes.h' file not found " or getting "Expected namespace name" error for " using namespace CryptoPP; " or similar compilation errors, refer to the following settings: Add "/usr/local/include" in Header search paths Add "/usr/local/lib" in Library search paths Add -lcryptopp as a Linker flag Refer to this article for more information:  https://com.puter.tips/2021/02/how-to-use-cryptopp-in-xcode.html These C++ build errors mean the compiler cannot find the Crypto++ headers or library, so the CryptoPP namespace looks undefined. The include and library search paths are not set. Adding /usr/local/include to the header search paths and the matching library path to the linker settings points the build at Crypto++ and clears both errors at once.

Using Boost C++ Libraries ( https://www.boost.org/ ) is relatively easier than setting up Cryptopp. [Ref.:  https://com.puter.tips/2021/02/how-to-use-cryptopp-in-xcode.html ] Step-1: Install boost libraries $ brew install boost Step-2: Link boost in Build Settings Navigate to Linking >> Other Linker Flags Add following flags as per your requirement -lboost_chrono -lboost_system -lboost_timer -lboost_regex This guide sets up the Boost C++ libraries in an Xcode project, which is simpler than wiring up some other libraries. After installing Boost with Homebrew, you add the linker flags so the project finds it. Boost is a large, widely used collection of peer reviewed C++ libraries, many of which later influenced the standard library. Getting the link settings right once lets you use any of them.

So I was working on a C++ project on Xcode, and I updated to the latest version of Xcode with recommended default settings; then I started having the following errors: dyld: Library not loaded: /usr/local/lib/libcryptopp.dylib    Referenced from: /Users/devharsh/Library/Developer/Xcode/DerivedData/server-bohvcuztzndrrzhcoglrvuijfasj/Build/Products/Debug/server    Reason: no suitable image found.    Did find: /usr/local/lib/libcryptopp.dylib: code signature in (/usr/local/lib/libcryptopp.dylib) not valid for use in process using Library Validation: mapped file has no cdhash, completely unsigned? Code has to be at least ad-hoc signed. /usr/local/lib/libcryptopp.dylib: code signature in (/usr/local/lib/libcryptopp.dylib) not valid for use in process using Library Validation: mapped file has no cdhash, completely unsigned? Code has to be at least ad-hoc signed. /usr/local/lib/libcryptopp.dylib: code signature in (/usr/local/lib/libcryptopp.dylib) not vali...

The error when you try to sign in to any Google service like Youtube or Google Drive from a corporate account: "We detected an unusual sign-in attempt. To ensure that someone else isn't trying to access your account, your organization needs you to sign in using your corporate mobile device (the phone or tablet you normally use to access your corporate account). If you don't have your corporate mobile device with you right now, try again later when you have your corporate mobile device with you. If you continue to have problems signing in, contact your administrator." To suppress this warning, you can: Login to Google Admin:  https://admin.google.com/ Go to Users >> Open the user account Go to "Login challenge." Click on "Turn off for 10 mins." Try to log in again, and it should be fine

I was working on a python3 script on my macOS, and I came across this error: % python3 my-random-script.py Unable to revert mtime: /Library/Fonts I got it solved by installing libmagic: % brew install libmagic This message on macOS comes from the python-magic library when its underlying libmagic dependency is missing. The script still runs but cannot read file type information and prints this warning. Installing libmagic with Homebrew, as shown, supplies the missing piece and clears the message. python-magic relies on the same system libmagic that the file command uses.

NTRU: NTRU – Nth Degree Truncated Polynomial Ring Units (or R = Z[X] / ( X^N-1 )) NTRU is the first public-key cryptosystem not based on factorization or discrete logarithmic problems. NTRU is a lattice-based alternative to RSA and ECC and is based on the shortest vector problem in a lattice. NTRU is an open-source public-key cryptosystem that uses lattice-based cryptography to encrypt and decrypt data. It consists of two algorithms: NTRUEncrypt, which is used for encryption, and NTRUSign, which is used for digital signatures. Unlike other popular public-key cryptosystems, it is resistant to attacks using Shor's algorithm. NTRUEncrypt was patented, but it was placed in the public domain in 2017. NTRUSign is patented, but it can be used by software under the GPL. Example in Python3: % python3 --version Python 3.9.1 % pip3 install --user sympy % pip3 install --user numpy % pip3 install --user docopt

Google Photos is a photo-sharing and storage service developed by Google . It was announced in May 2015 and separated from Google+, the company's former social network. In its free tier, Google Photos stores unlimited photos and videos up to 16 megapixels and 1080p resolution, respectively (anything larger gets down-scaled to these sizes). This free tier will end on June 1, 2021 . Photos and videos uploaded after that date get counted towards the 15 GB free quota shared across the user's Google services . There are subscriptions offered for users wanting to store their photos and videos at their "original" quality and requiring more storage than the 15 GB offered free. Storage (GB) Per Month (USD) Annual (USD) 15 0 0 100 1.99 19.99 200 2.99 29.99 2000 9.99 99.99 You can check out how much storage you are using across Google services out of your quota of free 15 GB. Go to Google Drive and check the storage bar on the left side. Or you can click on the Setting butto...

In this tutorial, I have installed a free SSL certificate from Let's Encrypt using the Certbot tool on Google Cloud Platform VM running Debian OS that hosts a WordPress site using Apache server. You can follow similar steps for other Cloud providers / OS distributions / CMS vendors / Web servers . Part-1: Configure Virtual Host for your domain on Apache cd /var/www/html wp option update home 'https://example.com' wp option update siteurl 'https://example.com' sudo nano /etc/apache2/sites-available/example.com.conf sudo apache2ctl configtest sudo a2ensite example.com sudo systemctl reload apache2

Code: // //   main.cpp //   VaultBox // //   Created by Devharsh Trivedi on 3/11/21. // #include <iostream> #include <iomanip> #include <string> #include <map> #include <random> #include <cmath> #include <vector> int main ( int argc, const char * argv[]) {     std :: random_device ranDev;     unsigned int num_ranDev = ranDev();     std :: cout << num_ranDev << std :: endl ;     std :: mt19937 mtGen(num_ranDev);     std :: vector < unsigned long > indexes( 10 );          iota (indexes. begin (), indexes. end (), 0 );     for ( int i= 0 ; i< 10 ; i++) {         std :: cout << indexes[i] << "\t" ;     }     std :: cout << std :: endl ;

Steps to save a locked (password protected) PDF as an unlocked PDF: Download / Save / Copy the locked PDF to a folder Open Google Chrome Go to File Menu >> Open File >> Select your locked PDF Enter password Click on the Print button and select Save as a PDF The saved PDF will be unlocked This trick removes the open password from a PDF you can already open, by opening it in Google Chrome, entering the password, and then printing it back to a new PDF without protection. It only works when you know the password and are allowed to access the file, so it is for convenience, not for bypassing protection you are not entitled to remove.

Problem code: if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT , &opt, sizeof(opt)))  {  perror("setsockopt");  exit(EXIT_FAILURE);  } Solution: if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR , &opt, sizeof(opt)))  {  perror("setsockopt");  exit(EXIT_FAILURE);  } Ref.:  https://stackoverflow.com/a/59807281/4064166 This error appears when a socket option is not supported on the current platform. Here the combination of SO_REUSEADDR and SO_REUSEPORT fails because SO_REUSEPORT is unavailable, so the call returns Protocol not available. Setting SO_REUSEADDR on its own fixes it, which is widely supported and enough for the common case of rebinding a recently used address. SO_REUSEPORT behaves differently across operating systems and is not always present.

1. Check if you have enough free storage on iCloud 2. Go to Settings (iOS / iPadOS) or System Preferences (macOS) >> iCloud >> Sign Out 3. Wait for a minute or two after you have successfully logged out 4. Log in to iCloud again 5. Go to iCloud settings and >> iCloud Drive >> Options... >> select the checkbox for "Desktop & Documents Folder" >> Done

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Crypto++ Library is a free C++ class library of cryptographic schemes. Currently the library contains the following algorithms: algorithm type name authenticated encryption schemes GCM, CCM, EAX, ChaCha20Poly1305 and XChaCha20Poly1305 high speed stream ciphers ChaCha (8/12/20), ChaCha (IETF), Panama, Salsa20, Sosemanuk, XSalsa20, XChaCha20 AES and AES candidates AES (Rijndael), RC6, MARS, Twofish, Serpent, CAST-256 ARIA, Blowfish, Camellia, CHAM, HIGHT, IDEA, Kalyna (128/256/512), LEA, SEED, RC5, SHACAL-2, other block ciphers SIMON (64/128), Skipjack, SPECK (64/128), Simeck, SM4, Threefish (256/512/1024), Triple-DES (DES-EDE2 and DES-EDE3), TEA, XTEA block cipher modes of operati...

Steps to check if Intel SGX is enabled on your system: 1. Download test-sgx.c from  https://github.com/ayeks/SGX-hardware 2. % gcc test-sgx.c -o test-sgx 3.  % ./test-sgx eax: 806ea ebx: 4100800 ecx: 7ffafbbf edx: bfebfbff stepping 10 model 14 family 6 processor type 0 extended model 8 extended family 0 smx: 0 Extended feature bits (EAX=07H, ECX=0H) eax: 0 ebx: 29c67af ecx: 0 edx: 9c002600 sgx available: 1 sgx launch control: 0 CPUID Leaf 12H, Sub-Leaf 0 of Intel SGX Capabilities (EAX=12H,ECX=0) eax: 0 ebx: 0 ecx: 0 edx: 0 sgx 1 supported: 0 sgx 2 supported: 0 MaxEnclaveSize_Not64: 0 MaxEnclaveSize_64: 0 CPUID Leaf 12H, Sub-Leaf 1 of Intel SGX Capabilities (EAX=12H,ECX=1) eax: 0 ebx: 0 ecx: 0 edx: 0 CPUID Leaf 12H, Sub-Leaf 2 of Intel SGX Capabilities (EAX=12H,ECX=2) eax: 0 ebx: 0 ecx: 0 edx: 0 CPUID Leaf 12H, Sub-Leaf 3 of Intel SGX Capabilities (EAX=12H,ECX=3) eax: 0 ebx: 0 ecx: 0 edx: 0 CPUID Leaf 12H, Sub-Leaf 4 of Intel SGX Capabilities (EAX=12H,ECX=4) eax: 0 ebx: 0 ...

Apple iOS Google Android Released July 29, 2007 September 23, 2008 Latest Version 14 11 Website https://www.apple.com/ios/ios-14/ https://www.android.com/ OS Model Proprietary Open Source Languages 40 100 Assistant Siri Google Assistant Apps 1,000,000 on App Store 2,000,000 on Play Store Operating System Unix Linux Latest Phone iPhone 12 Pixel 5 Phone Website https://www.apple.com/iphone https://store.google.com/product/pixel_5 Let's compare some of the default apps on both platforms...