Using JWT for Authentication in a Golang Application

Introduction

A JSON Web Token (JWT) is a compact and self-contained way of securely transmitting information between parties as a JSON object, and they are commonly used by developers in their APIs. JWTs are popular because:

A JWT is stateless. That is, it does not need to be stored in a database (persistence layer), unlike opaque tokens.
The signature of a JWT is never decoded once formed, thereby ensuring that the token is safe and secure.
A JWT can be set to be invalid after a certain period of time. This helps minimize or totally eliminate any damage that can be done by a hacker, in the event that the token is hijacked.

In this tutorial, I will demonstrate the creation, use, and invalidation of a JWT with a simple RESTful API using Golang and the Vonage Messages API.

Vonage API Account

To complete this tutorial, you will need a Vonage API account. If you don’t have one already, you can sign up today and start building with free credit. Once you have an account, you can find your API Key and API Secret at the top of the Vonage API Dashboard.

This tutorial also uses a virtual phone number. To purchase one, go to Numbers > Buy Numbers and search for one that meets your needs. If you’ve just signed up, the initial cost of a number will be easily covered by your available credit.

Image for post

A JWT is comprised of three parts:

Header: the type of token and the signing algorithm used. The type of token can be “JWT” while the Signing Algorithm can either be HMAC or SHA256.
Payload: the second part of the token which contains the claims. These claims include application-specific data(e.g, user id, username), token expiration time(exp), issuer(iss), subject(sub), and so on.
Signature: the encoded header, encoded payload, and a secret you provide are used to create the signature.

Let’s use a simple token to understand the above concepts.

Token = eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJhdXRoX3V1aWQiOiIxZGQ5MDEwYy00MzI4LTRmZjMtYjllNi05NDRkODQ4ZTkzNzUiLCJhdXRob3JpemVkIjp0cnVlLCJ1c2VyX2lkIjo3fQ.Qy8l-9GUFsXQm4jqgswAYTAX9F4cngrl28WJVYNDwtM

Don’t worry, the token is invalid, so it won’t work on any production application.

You can navigate to jwt.to and test the token signature if it is verified or not. Use “HS512” as the algorithm. You will get the message “Signature Verified”:

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To make the signature, your application will need to provide a key. This key enables the signature to remain secure-even when the JWT is decoded the signature remains encrypted. It is highly recommended to always use a secret when creating a JWT.

Token Types

Since a JWT can be set to expire (be invalidated) after a particular period of time, two tokens will be considered in this application:

Access Token: An access token is used for requests that require authentication. It is normally added in the header of the request. It is recommended that an access token has a short lifespan, say 15 minutes. Giving an access token a short time span can prevent any serious damage if a user’s token is tampered with. In the event that the token is hijacked, the hacker only has 15 minutes or less to carry out his operations before the token is invalidated.
Refresh Token: A refresh token has a longer lifespan, usually seven days. This token is used to generate new access and refresh tokens. In the event that the access token expires, new sets of access and refresh tokens are created when the refresh token route is hit (from our application).

Where to Store a JWT

For a production grade application, it is highly recommended that you store JWTs in an HttpOnly cookie. To achieve this, while sending the cookie generated from the backend to the frontend (client), a HttpOnly flag is sent along the cookie, instructing the browser not to display the cookie through the client-side scripts. Doing this can prevent XSS (Cross Site Scripting) attacks. JWT can also be stored in browser local storage or session storage. Storing a JWT this way can expose it to several attacks such as XSS mentioned above, so it is generally less secure when compared to using `HttpOnly cookie technique.

#jwt #security #golang #programming #developer

What is GEEK

Buddha Community

Using JWT for Authentication in a Golang Application

Chloe Butler

1667425440

Pdf2gerb: Perl Script Converts PDF Files to Gerber format

pdf2gerb

Perl script converts PDF files to Gerber format

Pdf2Gerb generates Gerber 274X photoplotting and Excellon drill files from PDFs of a PCB. Up to three PDFs are used: the top copper layer, the bottom copper layer (for 2-sided PCBs), and an optional silk screen layer. The PDFs can be created directly from any PDF drawing software, or a PDF print driver can be used to capture the Print output if the drawing software does not directly support output to PDF.

The general workflow is as follows:

Design the PCB using your favorite CAD or drawing software.
Print the top and bottom copper and top silk screen layers to a PDF file.
Run Pdf2Gerb on the PDFs to create Gerber and Excellon files.
Use a Gerber viewer to double-check the output against the original PCB design.
Make adjustments as needed.
Submit the files to a PCB manufacturer.

Please note that Pdf2Gerb does NOT perform DRC (Design Rule Checks), as these will vary according to individual PCB manufacturer conventions and capabilities. Also note that Pdf2Gerb is not perfect, so the output files must always be checked before submitting them. As of version 1.6, Pdf2Gerb supports most PCB elements, such as round and square pads, round holes, traces, SMD pads, ground planes, no-fill areas, and panelization. However, because it interprets the graphical output of a Print function, there are limitations in what it can recognize (or there may be bugs).

See docs/Pdf2Gerb.pdf for install/setup, config, usage, and other info.

pdf2gerb_cfg.pm

#Pdf2Gerb config settings:
#Put this file in same folder/directory as pdf2gerb.pl itself (global settings),
#or copy to another folder/directory with PDFs if you want PCB-specific settings.
#There is only one user of this file, so we don't need a custom package or namespace.
#NOTE: all constants defined in here will be added to main namespace.
#package pdf2gerb_cfg;

use strict; #trap undef vars (easier debug)
use warnings; #other useful info (easier debug)


##############################################################################################
#configurable settings:
#change values here instead of in main pfg2gerb.pl file

use constant WANT_COLORS => ($^O !~ m/Win/); #ANSI colors no worky on Windows? this must be set < first DebugPrint() call

#just a little warning; set realistic expectations:
#DebugPrint("${\(CYAN)}Pdf2Gerb.pl ${\(VERSION)}, $^O O/S\n${\(YELLOW)}${\(BOLD)}${\(ITALIC)}This is EXPERIMENTAL software.  \nGerber files MAY CONTAIN ERRORS.  Please CHECK them before fabrication!${\(RESET)}", 0); #if WANT_DEBUG

use constant METRIC => FALSE; #set to TRUE for metric units (only affect final numbers in output files, not internal arithmetic)
use constant APERTURE_LIMIT => 0; #34; #max #apertures to use; generate warnings if too many apertures are used (0 to not check)
use constant DRILL_FMT => '2.4'; #'2.3'; #'2.4' is the default for PCB fab; change to '2.3' for CNC

use constant WANT_DEBUG => 0; #10; #level of debug wanted; higher == more, lower == less, 0 == none
use constant GERBER_DEBUG => 0; #level of debug to include in Gerber file; DON'T USE FOR FABRICATION
use constant WANT_STREAMS => FALSE; #TRUE; #save decompressed streams to files (for debug)
use constant WANT_ALLINPUT => FALSE; #TRUE; #save entire input stream (for debug ONLY)

#DebugPrint(sprintf("${\(CYAN)}DEBUG: stdout %d, gerber %d, want streams? %d, all input? %d, O/S: $^O, Perl: $]${\(RESET)}\n", WANT_DEBUG, GERBER_DEBUG, WANT_STREAMS, WANT_ALLINPUT), 1);
#DebugPrint(sprintf("max int = %d, min int = %d\n", MAXINT, MININT), 1); 

#define standard trace and pad sizes to reduce scaling or PDF rendering errors:
#This avoids weird aperture settings and replaces them with more standardized values.
#(I'm not sure how photoplotters handle strange sizes).
#Fewer choices here gives more accurate mapping in the final Gerber files.
#units are in inches
use constant TOOL_SIZES => #add more as desired
(
#round or square pads (> 0) and drills (< 0):
    .010, -.001,  #tiny pads for SMD; dummy drill size (too small for practical use, but needed so StandardTool will use this entry)
    .031, -.014,  #used for vias
    .041, -.020,  #smallest non-filled plated hole
    .051, -.025,
    .056, -.029,  #useful for IC pins
    .070, -.033,
    .075, -.040,  #heavier leads
#    .090, -.043,  #NOTE: 600 dpi is not high enough resolution to reliably distinguish between .043" and .046", so choose 1 of the 2 here
    .100, -.046,
    .115, -.052,
    .130, -.061,
    .140, -.067,
    .150, -.079,
    .175, -.088,
    .190, -.093,
    .200, -.100,
    .220, -.110,
    .160, -.125,  #useful for mounting holes
#some additional pad sizes without holes (repeat a previous hole size if you just want the pad size):
    .090, -.040,  #want a .090 pad option, but use dummy hole size
    .065, -.040, #.065 x .065 rect pad
    .035, -.040, #.035 x .065 rect pad
#traces:
    .001,  #too thin for real traces; use only for board outlines
    .006,  #minimum real trace width; mainly used for text
    .008,  #mainly used for mid-sized text, not traces
    .010,  #minimum recommended trace width for low-current signals
    .012,
    .015,  #moderate low-voltage current
    .020,  #heavier trace for power, ground (even if a lighter one is adequate)
    .025,
    .030,  #heavy-current traces; be careful with these ones!
    .040,
    .050,
    .060,
    .080,
    .100,
    .120,
);
#Areas larger than the values below will be filled with parallel lines:
#This cuts down on the number of aperture sizes used.
#Set to 0 to always use an aperture or drill, regardless of size.
use constant { MAX_APERTURE => max((TOOL_SIZES)) + .004, MAX_DRILL => -min((TOOL_SIZES)) + .004 }; #max aperture and drill sizes (plus a little tolerance)
#DebugPrint(sprintf("using %d standard tool sizes: %s, max aper %.3f, max drill %.3f\n", scalar((TOOL_SIZES)), join(", ", (TOOL_SIZES)), MAX_APERTURE, MAX_DRILL), 1);

#NOTE: Compare the PDF to the original CAD file to check the accuracy of the PDF rendering and parsing!
#for example, the CAD software I used generated the following circles for holes:
#CAD hole size:   parsed PDF diameter:      error:
#  .014                .016                +.002
#  .020                .02267              +.00267
#  .025                .026                +.001
#  .029                .03167              +.00267
#  .033                .036                +.003
#  .040                .04267              +.00267
#This was usually ~ .002" - .003" too big compared to the hole as displayed in the CAD software.
#To compensate for PDF rendering errors (either during CAD Print function or PDF parsing logic), adjust the values below as needed.
#units are pixels; for example, a value of 2.4 at 600 dpi = .0004 inch, 2 at 600 dpi = .0033"
use constant
{
    HOLE_ADJUST => -0.004 * 600, #-2.6, #holes seemed to be slightly oversized (by .002" - .004"), so shrink them a little
    RNDPAD_ADJUST => -0.003 * 600, #-2, #-2.4, #round pads seemed to be slightly oversized, so shrink them a little
    SQRPAD_ADJUST => +0.001 * 600, #+.5, #square pads are sometimes too small by .00067, so bump them up a little
    RECTPAD_ADJUST => 0, #(pixels) rectangular pads seem to be okay? (not tested much)
    TRACE_ADJUST => 0, #(pixels) traces seemed to be okay?
    REDUCE_TOLERANCE => .001, #(inches) allow this much variation when reducing circles and rects
};

#Also, my CAD's Print function or the PDF print driver I used was a little off for circles, so define some additional adjustment values here:
#Values are added to X/Y coordinates; units are pixels; for example, a value of 1 at 600 dpi would be ~= .002 inch
use constant
{
    CIRCLE_ADJUST_MINX => 0,
    CIRCLE_ADJUST_MINY => -0.001 * 600, #-1, #circles were a little too high, so nudge them a little lower
    CIRCLE_ADJUST_MAXX => +0.001 * 600, #+1, #circles were a little too far to the left, so nudge them a little to the right
    CIRCLE_ADJUST_MAXY => 0,
    SUBST_CIRCLE_CLIPRECT => FALSE, #generate circle and substitute for clip rects (to compensate for the way some CAD software draws circles)
    WANT_CLIPRECT => TRUE, #FALSE, #AI doesn't need clip rect at all? should be on normally?
    RECT_COMPLETION => FALSE, #TRUE, #fill in 4th side of rect when 3 sides found
};

#allow .012 clearance around pads for solder mask:
#This value effectively adjusts pad sizes in the TOOL_SIZES list above (only for solder mask layers).
use constant SOLDER_MARGIN => +.012; #units are inches

#line join/cap styles:
use constant
{
    CAP_NONE => 0, #butt (none); line is exact length
    CAP_ROUND => 1, #round cap/join; line overhangs by a semi-circle at either end
    CAP_SQUARE => 2, #square cap/join; line overhangs by a half square on either end
    CAP_OVERRIDE => FALSE, #cap style overrides drawing logic
};
    
#number of elements in each shape type:
use constant
{
    RECT_SHAPELEN => 6, #x0, y0, x1, y1, count, "rect" (start, end corners)
    LINE_SHAPELEN => 6, #x0, y0, x1, y1, count, "line" (line seg)
    CURVE_SHAPELEN => 10, #xstart, ystart, x0, y0, x1, y1, xend, yend, count, "curve" (bezier 2 points)
    CIRCLE_SHAPELEN => 5, #x, y, 5, count, "circle" (center + radius)
};
#const my %SHAPELEN =
#Readonly my %SHAPELEN =>
our %SHAPELEN =
(
    rect => RECT_SHAPELEN,
    line => LINE_SHAPELEN,
    curve => CURVE_SHAPELEN,
    circle => CIRCLE_SHAPELEN,
);

#panelization:
#This will repeat the entire body the number of times indicated along the X or Y axes (files grow accordingly).
#Display elements that overhang PCB boundary can be squashed or left as-is (typically text or other silk screen markings).
#Set "overhangs" TRUE to allow overhangs, FALSE to truncate them.
#xpad and ypad allow margins to be added around outer edge of panelized PCB.
use constant PANELIZE => {'x' => 1, 'y' => 1, 'xpad' => 0, 'ypad' => 0, 'overhangs' => TRUE}; #number of times to repeat in X and Y directions

# Set this to 1 if you need TurboCAD support.
#$turboCAD = FALSE; #is this still needed as an option?

#CIRCAD pad generation uses an appropriate aperture, then moves it (stroke) "a little" - we use this to find pads and distinguish them from PCB holes. 
use constant PAD_STROKE => 0.3; #0.0005 * 600; #units are pixels
#convert very short traces to pads or holes:
use constant TRACE_MINLEN => .001; #units are inches
#use constant ALWAYS_XY => TRUE; #FALSE; #force XY even if X or Y doesn't change; NOTE: needs to be TRUE for all pads to show in FlatCAM and ViewPlot
use constant REMOVE_POLARITY => FALSE; #TRUE; #set to remove subtractive (negative) polarity; NOTE: must be FALSE for ground planes

#PDF uses "points", each point = 1/72 inch
#combined with a PDF scale factor of .12, this gives 600 dpi resolution (1/72 * .12 = 600 dpi)
use constant INCHES_PER_POINT => 1/72; #0.0138888889; #multiply point-size by this to get inches

# The precision used when computing a bezier curve. Higher numbers are more precise but slower (and generate larger files).
#$bezierPrecision = 100;
use constant BEZIER_PRECISION => 36; #100; #use const; reduced for faster rendering (mainly used for silk screen and thermal pads)

# Ground planes and silk screen or larger copper rectangles or circles are filled line-by-line using this resolution.
use constant FILL_WIDTH => .01; #fill at most 0.01 inch at a time

# The max number of characters to read into memory
use constant MAX_BYTES => 10 * M; #bumped up to 10 MB, use const

use constant DUP_DRILL1 => TRUE; #FALSE; #kludge: ViewPlot doesn't load drill files that are too small so duplicate first tool

my $runtime = time(); #Time::HiRes::gettimeofday(); #measure my execution time

print STDERR "Loaded config settings from '${\(__FILE__)}'.\n";
1; #last value must be truthful to indicate successful load


#############################################################################################
#junk/experiment:

#use Package::Constants;
#use Exporter qw(import); #https://perldoc.perl.org/Exporter.html

#my $caller = "pdf2gerb::";

#sub cfg
#{
#    my $proto = shift;
#    my $class = ref($proto) || $proto;
#    my $settings =
#    {
#        $WANT_DEBUG => 990, #10; #level of debug wanted; higher == more, lower == less, 0 == none
#    };
#    bless($settings, $class);
#    return $settings;
#}

#use constant HELLO => "hi there2"; #"main::HELLO" => "hi there";
#use constant GOODBYE => 14; #"main::GOODBYE" => 12;

#print STDERR "read cfg file\n";

#our @EXPORT_OK = Package::Constants->list(__PACKAGE__); #https://www.perlmonks.org/?node_id=1072691; NOTE: "_OK" skips short/common names

#print STDERR scalar(@EXPORT_OK) . " consts exported:\n";
#foreach(@EXPORT_OK) { print STDERR "$_\n"; }
#my $val = main::thing("xyz");
#print STDERR "caller gave me $val\n";
#foreach my $arg (@ARGV) { print STDERR "arg $arg\n"; }

Download Details:

Author: swannman
Source Code: https://github.com/swannman/pdf2gerb

License: GPL-3.0 license

#perl

German Donnelly

1592807820

How To Set Up Two-Factor Authentication in cPanel

What is 2FA
Two-Factor Authentication (or 2FA as it often referred to) is an extra layer of security that is used to provide users an additional level of protection when securing access to an account.
Employing a 2FA mechanism is a vast improvement in security over the Singe-Factor Authentication method of simply employing a username and password. Using this method, accounts that have 2FA enabled, require the user to enter a one-time passcode that is generated by an external application. The 2FA passcode (usually a six-digit number) is required to be input into the passcode field before access is granted. The 2FA input is usually required directly after the username and password are entered by the client.

#tutorials #2fa #access #account security #authentication #authentication method #authentication token #cli #command line #cpanel #feature manager #google authenticator #one time password #otp #otp authentication #passcode #password #passwords #qr code #security #security code #security policy #security practices #single factor authentication #time-based one-time password #totp #two factor authentication #whm

https://ozenero.com Programming Tutorial

1606729959

React Node Jwt Authentication without Redux - using LocalStorage and Axios

https://loizenai.com/react-node-jwt-authentication/

Tutorial Link: React Node Jwt authentication withoud Redux

React Node Jwt Authentication without Redux

Tutorial: React Node Jwt Authentication (without Redux) – using LocalStorage and Axios (plus interceptor) in React application and Express + Sequelize + MySQL/PostgreSQL in Nodejs backend solution.

JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. And “How to build Reactjs Nodejs Jwt Token Based Authentication Example?” is one of the most common questions for SpringBoot Java development world. So in the tutorial, I introduce how to implement an application “Reactjs JWT SpringBoot token Authentication Example” with details step by step and 100% running sourcecode.

– I give you an Epic of the application, a fullstack excutive flow from frontend (Reactjs) to backend (Nodejs/Express) to database (MySQL/PostgreSQL) with overall architecture diagram.
– I give you a layer diagram of Reactjs Jwt Application with LocalStorage and Axios (plus Interceptor)
– I guide you detail-steps how to implement a security Jwt Token Nodejs backend.
– I guide you step by step how to develop a Reactjs Jwt Authentication application.
– Finally, I do an integrative testing from Reactjs Jwt Authentication application to jwt Nodejs Security RestAPIs.

Overall Jwt Login System Architecture Diagram

For the Reactjs JWT Authentication tutorial, we have 2 projects:
– Backend project Nodejs/Express provides secured RestAPIs with JWT token.
– Reactjs project will request RestAPIs from Nodejs with the Jwt Token Authentication implementation.

JWT Authentication Sequence Diagram

The diagram below show how our system handles User Registration and User Login processes:

Reactjs Node Jwt Authentication Working Process Diagram

User Registration Phase:
– User uses a React.js register form to post user’s info (name, username, email, role, password) to Backend API /api/auth/signup.
– Backend will check the existing users in database and save user’s signup info to database. Finally, It will return a message (successfully or fail) to
User Login Phase:
– User posts user/password to signin to Backend RestAPI /api/auth/signin.
– Backend will check the username/password, if it is right, Backend will create and JWT string with secret then return it to Reactjs client.

After signin, user can request secured resources from backend server by adding the JWT token in Authorization Header. For each request, backend will check the JWT signature and then returns back the resources based on user’s registered authorities.

Reactjs JWT Authentication Diagram Overview

Reactjs JWT Authentication would be built with 5 main kind blocks:

Reactjs Router is a standard library for routing in React. It enables the navigation among views of various components in a React Application, allows changing the browser URL, and keeps the UI in sync with the URL.
Reactjs Components let you split the UI into independent, reusable pieces, and think about each piece in isolation.
Reactjs Service is a bridge between Reactjs Component and Backend Server, it is used to do technical logic with Backend Server (using Ajax Engine to fetch data from Backend, or using Local Storage to save user login data) and returned a response data to React.js Components
Local Storage allow to save key/value pairs in a web browser. It is a place to save the login user’s info.
Axios – (an Ajax Engine) is a promise-based HTTP client for the browser and Node. js. Axios makes it easy to send asynchronous HTTP requests to REST endpoints and perform CRUD operations.

Jwt Nodejs Token Security RestAPIs Diagram Overview

HTTP request that matches route will be accepted by CORS Middleware before coming to Security layer.

Security layer includes:
– JWT Authentication Middleware: verify SignUp, verify token
– Authorization Middleware: check User’s roles

Main Business Logic Processing interacts with database via Sequelize and send HTTP response (token, user information, data based on roles…) to client.

Project Goal

We create a Reactjs JWT Authentication project as below:

Project Structure

It includes 8 components and 2 services and a router in app.js file.

– Home page:

Home page

– User Register page:

User Register page

– Login Page:

Login Page

– Profile Page:

– Use Page:

Use Page

– Project Manager Page:

– Reactjs Admin page:

Reactjs Admin page

How to Use JWT for Authentication in a Golang Application

Introduction

A JSON Web Token (JWT) is a compact and self-contained way for securely transmitting information between parties as a JSON object, and they are commonly used by developers in their APIs. JWTs are popular because:

A JWT is stateless. That is, it does not need to be stored in a database (persistence layer), unlike opaque tokens.
The signature of a JWT is never decoded once formed, thereby ensuring that the token is safe and secure.
A JWT can be set to be invalid after a certain period of time. This helps minimize or totally eliminate any damage that can be done by a hacker, in the event that the token is hijacked.

In this tutorial, I will demonstrate the creation, use, and invalidation of a JWT with a simple RESTful API using Golang and the Vonage Messages API.

Vonage API Account

To complete this tutorial, you will need a Vonage API account. If you don’t have one already, you can sign up today and start building with free credit. Once you have an account, you can find your API Key and API Secret at the top of the Vonage API Dashboard.

This tutorial also uses a virtual phone number. To purchase one, go to Numbers > Buy Numbers and search for one that meets your needs. If you’ve just signed up, the initial cost of a number will be easily covered by your available credit.

#golang #go #jwt

Precious Heaney

1602298045