The Ultimate Go Guide in 2020 for Beginners.

Go is an open-source programming language that makes it easy to build simple, reliable, and efficient software. In this article, I’ll make sure you get the fundamentals of the Go Programming Language.

Getting Started

First, we need to install the Go programming language.

How to write code for Go

Go programs are organized into packages. A package is a collection of source files in the same directory that are compiled together. Functions, types, variables, and constants defined in one source file are visible to all other source files within the same package.

#programming #tech #go #google #golang

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Citrix Bugs Allow Unauthenticated Code Injection, Data Theft

Multiple vulnerabilities in the Citrix Application Delivery Controller (ADC) and Gateway would allow code injection, information disclosure and denial of service, the networking vendor announced Tuesday. Four of the bugs are exploitable by an unauthenticated, remote attacker.

The Citrix products (formerly known as NetScaler ADC and Gateway) are used for application-aware traffic management and secure remote access, respectively, and are installed in at least 80,000 companies in 158 countries, according to a December assessment from Positive Technologies.

Other flaws announced Tuesday also affect Citrix SD-WAN WANOP appliances, models 4000-WO, 4100-WO, 5000-WO and 5100-WO.

Attacks on the management interface of the products could result in system compromise by an unauthenticated user on the management network; or system compromise through cross-site scripting (XSS). Attackers could also create a download link for the device which, if downloaded and then executed by an unauthenticated user on the management network, could result in the compromise of a local computer.

“Customers who have configured their systems in accordance with Citrix recommendations [i.e., to have this interface separated from the network and protected by a firewall] have significantly reduced their risk from attacks to the management interface,” according to the vendor.

Threat actors could also mount attacks on Virtual IPs (VIPs). VIPs, among other things, are used to provide users with a unique IP address for communicating with network resources for applications that do not allow multiple connections or users from the same IP address.

The VIP attacks include denial of service against either the Gateway or Authentication virtual servers by an unauthenticated user; or remote port scanning of the internal network by an authenticated Citrix Gateway user.

“Attackers can only discern whether a TLS connection is possible with the port and cannot communicate further with the end devices,” according to the critical Citrix advisory. “Customers who have not enabled either the Gateway or Authentication virtual servers are not at risk from attacks that are applicable to those servers. Other virtual servers e.g. load balancing and content switching virtual servers are not affected by these issues.”

A final vulnerability has been found in Citrix Gateway Plug-in for Linux that would allow a local logged-on user of a Linux system with that plug-in installed to elevate their privileges to an administrator account on that computer, the company said.

#vulnerabilities #adc #citrix #code injection #critical advisory #cve-2020-8187 #cve-2020-8190 #cve-2020-8191 #cve-2020-8193 #cve-2020-8194 #cve-2020-8195 #cve-2020-8196 #cve-2020-8197 #cve-2020-8198 #cve-2020-8199 #denial of service #gateway #information disclosure #patches #security advisory #security bugs

What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

The Ultimate SQL Guide for Beginners in 2020.

SQL is a standard language for storing, manipulating, and retrieving data in databases. In this article, I’ll teach you the very basic fundamentals of the SQL language and hope you will be able to write your own database queries at the end.

What does SQL Mean?

SQL stands for Structured Query Language and lets you access and manipulate databases.

Syntax

Most of the actions you need to perform on a database are done with SQL statements. The following SQL statement selects all the records in the “Users” table:

SELECT * FROM Users;

Select

The select statement is used to retrieve data from a database. The requested data is returned in a results table.

SELECT column1 FROM table_name;

Select Distinct

The Select Distinct statement is used to return only distinct (different) values.

SELECT DISTINCT * FROM table_name;

Count

The following SQL statement lists the number of different customer countries:

SELECT COUNT(DISTINCT Country) FROM Customers;

Where

The Where clause is used to filter records.

SELECT column1
FROM table_name
WHERE condition;

For example:

SELECT * FROM Users
WHERE Country='Netherlands';

AND, OR and NOT Operators

The Where clause can be combined with AND, OR, and NOT operators. The AND and OR operators are used to filter records based on more than one condition:

• The AND operator displays a record if all the conditions separated by AND are TRUE.
• The OR operator displays a record if any of the conditions separated by OR is TRUE.

The NOT operator displays a record if the condition(s) is NOT TRUE.

AND

SELECT column1, column2, ...
FROM table_name
WHERE condition1 AND condition2 AND condition3 ...;

OR

SELECT column1, column2, ...
FROM table_name
WHERE condition1 OR condition2 OR condition3 ...;

NOT

SELECT column1, column2, ...
FROM table_name
WHERE NOT condition;

#tech #guides-and-tutorials #sql #beginners-guide #programming

The Ultimate React Guide For Beginners In 2020.

The Ultimate React Guide For Beginners In 2020. By Caspar Camille Rubin on Unsplash. React is a JavaScript library created by Facebook and is a great tool for building UI components.

#programming #javascript #guides-and-tutorials #tech #beginners-guide

The Ultimate Golang Guide in 2020 for Beginners

Go is an open-source programming language that makes it easy to build simple, reliable, and efficient software. In this article, I’ll make sure you get the fundamentals of the Go Programming Language.

Getting Started

First, we need to install the Go programming language.

How to write code for Go

Go programs are organized into packages. A package is a collection of source files in the same directory that are compiled together. Functions, types, variables, and constants defined in one source file are visible to all other source files within the same package.

To compile and run a simple program, choose a module path, and create a ‘go .mod’ file that declares it:

$ mkdir go-project
$ cd go-project
$ go mod init go-project
go: creating new go.mod: module go-project
$ cat go.mod module go-project
$

Next, create a file named app.go inside that directory containing the following Go code:

package main

import "fmt"
func main() {
	fmt.Println("Hello Medium")
}

Now you can build and install that program with the go tool:

$ go install go-project

This command builds the go-project command, producing an executable binary.

#go #guid #google #golang