1604127610
How to switch this.$refs and this.$el in the Vue 3 Composition API
In this article, we find out how to use the new ref() function as a replacement for static and dynamic HTML element references.
The new setup component option is executed before the component is created, once the props are resolved, and serves as the entry point for Composition API’s.
Because the component instance is not yet created when setup is executed, there is no this inside a setup option. This means, with the exception of props, you won’t be able to access any properties declared in the component – local state, computed properties or methods.
When using the Vue 3 Composition API via the setup() method, we don’t have access to this.$refs or this.$el. We can use the new ref() function for the same result.
<template>
<div ref="el">Hello Vue 3</div>
</template>
<script>
import { ref, onMounted } from 'vue'
export default {
setup() {
const el = ref(null)
onMounted(() => {
// the DOM element will be assigned to the ref after initial render
console.log(el.value) // <div>Hello Vue 3</div>
})
return {
el
}
}
}
</script>
Usage with Render Function / JSX
export default {
setup() {
const el = ref(null)
return () =>
h('div', {
ref: el
})
// with JSX
return () => <div ref={el} />
}
}
Usage inside v-for
Composition API template refs do not have special handling when used inside v-for. Instead, use function refs (new feature in 3.0) to perform custom handling:
<template>
<div v-for="(item, i) in list" :ref="el => { divs[i] = el }">
{{ item }}
</div>
</template>
<script>
import { ref, reactive, onBeforeUpdate } from 'vue'
export default {
setup() {
const list = reactive([1, 2, 3])
const divs = ref([])
// make sure to reset the refs before each update
onBeforeUpdate(() => {
divs.value = []
})
return {
list,
divs
}
}
}
</script>
#vue 3 #composition api #vue #vuejs #javascript
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1604127610
How to switch this.$refs and this.$el in the Vue 3 Composition API
In this article, we find out how to use the new ref() function as a replacement for static and dynamic HTML element references.
The new setup component option is executed before the component is created, once the props are resolved, and serves as the entry point for Composition API’s.
Because the component instance is not yet created when setup is executed, there is no this inside a setup option. This means, with the exception of props, you won’t be able to access any properties declared in the component – local state, computed properties or methods.
When using the Vue 3 Composition API via the setup() method, we don’t have access to this.$refs or this.$el. We can use the new ref() function for the same result.
<template>
<div ref="el">Hello Vue 3</div>
</template>
<script>
import { ref, onMounted } from 'vue'
export default {
setup() {
const el = ref(null)
onMounted(() => {
// the DOM element will be assigned to the ref after initial render
console.log(el.value) // <div>Hello Vue 3</div>
})
return {
el
}
}
}
</script>
Usage with Render Function / JSX
export default {
setup() {
const el = ref(null)
return () =>
h('div', {
ref: el
})
// with JSX
return () => <div ref={el} />
}
}
Usage inside v-for
Composition API template refs do not have special handling when used inside v-for. Instead, use function refs (new feature in 3.0) to perform custom handling:
<template>
<div v-for="(item, i) in list" :ref="el => { divs[i] = el }">
{{ item }}
</div>
</template>
<script>
import { ref, reactive, onBeforeUpdate } from 'vue'
export default {
setup() {
const list = reactive([1, 2, 3])
const divs = ref([])
// make sure to reset the refs before each update
onBeforeUpdate(() => {
divs.value = []
})
return {
list,
divs
}
}
}
</script>
#vue 3 #composition api #vue #vuejs #javascript
1589900677
Vue 3 Infinite Scroll with the Composition API
At the time of writing, Vue.js version 3 is in beta. However, that doesn’t mean we can’t start using it. In fact, this the best time to start experimenting with the new API and get ready for the official release.
In this tutorial, we will be building an infinite scroll hook with the new Composition API. we will be creating reactive-data, computed values, and using lifecycle methods.
#vue #composition-api #vue 3 #api
1595396220
Top 10 API Security Threats Every API Team Should Know
As more and more data is exposed via APIs either as API-first companies or for the explosion of single page apps/JAMStack, API security can no longer be an afterthought. The hard part about APIs is that it provides direct access to large amounts of data while bypassing browser precautions. Instead of worrying about SQL injection and XSS issues, you should be concerned about the bad actor who was able to paginate through all your customer records and their data.
Typical prevention mechanisms like Captchas and browser fingerprinting won’t work since APIs by design need to handle a very large number of API accesses even by a single customer. So where do you start? The first thing is to put yourself in the shoes of a hacker and then instrument your APIs to detect and block common attacks along with unknown unknowns for zero-day exploits. Some of these are on the OWASP Security API list, but not all.
Insecure pagination and resource limits
Most APIs provide access to resources that are lists of entities such as /users or /widgets. A client such as a browser would typically filter and paginate through this list to limit the number items returned to a client like so:
First Call: GET /items?skip=0&take=10
Second Call: GET /items?skip=10&take=10
However, if that entity has any PII or other information, then a hacker could scrape that endpoint to get a dump of all entities in your database. This could be most dangerous if those entities accidently exposed PII or other sensitive information, but could also be dangerous in providing competitors or others with adoption and usage stats for your business or provide scammers with a way to get large email lists. See how Venmo data was scraped
A naive protection mechanism would be to check the take count and throw an error if greater than 100 or 1000. The problem with this is two-fold:
- For data APIs, legitimate customers may need to fetch and sync a large number of records such as via cron jobs. Artificially small pagination limits can force your API to be very chatty decreasing overall throughput. Max limits are to ensure memory and scalability requirements are met (and prevent certain DDoS attacks), not to guarantee security.
- This offers zero protection to a hacker that writes a simple script that sleeps a random delay between repeated accesses.
skip = 0
while True: response = requests.post('https://api.acmeinc.com/widgets?take=10&skip=' + skip), headers={'Authorization': 'Bearer' + ' ' + sys.argv[1]}) print("Fetched 10 items") sleep(randint(100,1000)) skip += 10
How to secure against pagination attacks
To secure against pagination attacks, you should track how many items of a single resource are accessed within a certain time period for each user or API key rather than just at the request level. By tracking API resource access at the user level, you can block a user or API key once they hit a threshold such as “touched 1,000,000 items in a one hour period”. This is dependent on your API use case and can even be dependent on their subscription with you. Like a Captcha, this can slow down the speed that a hacker can exploit your API, like a Captcha if they have to create a new user account manually to create a new API key.
Insecure API key generation
Most APIs are protected by some sort of API key or JWT (JSON Web Token). This provides a natural way to track and protect your API as API security tools can detect abnormal API behavior and block access to an API key automatically. However, hackers will want to outsmart these mechanisms by generating and using a large pool of API keys from a large number of users just like a web hacker would use a large pool of IP addresses to circumvent DDoS protection.
How to secure against API key pools
The easiest way to secure against these types of attacks is by requiring a human to sign up for your service and generate API keys. Bot traffic can be prevented with things like Captcha and 2-Factor Authentication. Unless there is a legitimate business case, new users who sign up for your service should not have the ability to generate API keys programmatically. Instead, only trusted customers should have the ability to generate API keys programmatically. Go one step further and ensure any anomaly detection for abnormal behavior is done at the user and account level, not just for each API key.
Accidental key exposure
APIs are used in a way that increases the probability credentials are leaked:
- APIs are expected to be accessed over indefinite time periods, which increases the probability that a hacker obtains a valid API key that’s not expired. You save that API key in a server environment variable and forget about it. This is a drastic contrast to a user logging into an interactive website where the session expires after a short duration.
- The consumer of an API has direct access to the credentials such as when debugging via Postman or CURL. It only takes a single developer to accidently copy/pastes the CURL command containing the API key into a public forum like in GitHub Issues or Stack Overflow.
- API keys are usually bearer tokens without requiring any other identifying information. APIs cannot leverage things like one-time use tokens or 2-factor authentication.
If a key is exposed due to user error, one may think you as the API provider has any blame. However, security is all about reducing surface area and risk. Treat your customer data as if it’s your own and help them by adding guards that prevent accidental key exposure.
How to prevent accidental key exposure
The easiest way to prevent key exposure is by leveraging two tokens rather than one. A refresh token is stored as an environment variable and can only be used to generate short lived access tokens. Unlike the refresh token, these short lived tokens can access the resources, but are time limited such as in hours or days.
The customer will store the refresh token with other API keys. Then your SDK will generate access tokens on SDK init or when the last access token expires. If a CURL command gets pasted into a GitHub issue, then a hacker would need to use it within hours reducing the attack vector (unless it was the actual refresh token which is low probability)
Exposure to DDoS attacks
APIs open up entirely new business models where customers can access your API platform programmatically. However, this can make DDoS protection tricky. Most DDoS protection is designed to absorb and reject a large number of requests from bad actors during DDoS attacks but still need to let the good ones through. This requires fingerprinting the HTTP requests to check against what looks like bot traffic. This is much harder for API products as all traffic looks like bot traffic and is not coming from a browser where things like cookies are present.
Stopping DDoS attacks
The magical part about APIs is almost every access requires an API Key. If a request doesn’t have an API key, you can automatically reject it which is lightweight on your servers (Ensure authentication is short circuited very early before later middleware like request JSON parsing). So then how do you handle authenticated requests? The easiest is to leverage rate limit counters for each API key such as to handle X requests per minute and reject those above the threshold with a 429 HTTP response. There are a variety of algorithms to do this such as leaky bucket and fixed window counters.
Incorrect server security
APIs are no different than web servers when it comes to good server hygiene. Data can be leaked due to misconfigured SSL certificate or allowing non-HTTPS traffic. For modern applications, there is very little reason to accept non-HTTPS requests, but a customer could mistakenly issue a non HTTP request from their application or CURL exposing the API key. APIs do not have the protection of a browser so things like HSTS or redirect to HTTPS offer no protection.
How to ensure proper SSL
Test your SSL implementation over at Qualys SSL Test or similar tool. You should also block all non-HTTP requests which can be done within your load balancer. You should also remove any HTTP headers scrub any error messages that leak implementation details. If your API is used only by your own apps or can only be accessed server-side, then review Authoritative guide to Cross-Origin Resource Sharing for REST APIs
Incorrect caching headers
APIs provide access to dynamic data that’s scoped to each API key. Any caching implementation should have the ability to scope to an API key to prevent cross-pollution. Even if you don’t cache anything in your infrastructure, you could expose your customers to security holes. If a customer with a proxy server was using multiple API keys such as one for development and one for production, then they could see cross-pollinated data.
#api management #api security #api best practices #api providers #security analytics #api management policies #api access tokens #api access #api security risks #api access keys
1601381326
Public ASX100 APIs: The Essential List
We’ve conducted some initial research into the public APIs of the ASX100 because we regularly have conversations about what others are doing with their APIs and what best practices look like. Being able to point to good local examples and explain what is happening in Australia is a key part of this conversation.
Method
The method used for this initial research was to obtain a list of the ASX100 (as of 18 September 2020). Then work through each company looking at the following:
- Whether the company had a public API: this was found by googling “[company name] API” and “[company name] API developer” and “[company name] developer portal”. Sometimes the company’s website was navigated or searched.
- Some data points about the API were noted, such as the URL of the portal/documentation and the method they used to publish the API (portal, documentation, web page).
- Observations were recorded that piqued the interest of the researchers (you will find these below).
- Other notes were made to support future research.
- You will find a summary of the data in the infographic below.
Data
With regards to how the APIs are shared:
- Documentation is where just the Swagger/OpenAPI docs are hosted somewhere. e.g. https://api.linkgroup.com/member/docs/index
- Portal is where an interactive portal has been developed. e.g. https://dev.telstra.com/
- The web page is where the company has a single page that isn’t interactive explaining their Public APIs. e.g. https://www.bendigoadelaide.com.au/banking-products-api.asp
#api #api-development #api-analytics #apis #api-integration #api-testing #api-security #api-gateway
1595548860
Easily switch to Composition API in Vue.js 3
The fact that Vue.js 3 already reached the alpha version made me think that… it’s time already for some Vue.js 3 tips!
The idea is to give you some tips related to new features you can find on Vue.js 3 as they get available. For now, we’ll focus on Composition API, one of the most game-changing features!
This first one is specially focused on showing you a basic step-by-step guide or cheatsheet to migrate object-api Vue.js components to use Composition API. In future tips you’ll also see how to apply certain new techniques this API allow us to do as well.
I’ll do that by showing you how to convert an Object-API-based component to use Composition API.
For that, let’s create a MoneyCounter.vue component that basically shows a money amount and allow us to add/substract quantities to it, implemented using the following code:
<template>
<div>
<h2>{{ formattedMoney }}</h2>
<input v-model="delta" type="number">
<button @click="add">Add</button>
</div>
</template>
<script>
export default {
data: () => ({
money: 10,
delta: 1
}),
computed: {
formattedMoney() {
return this.money.toFixed(2);
}
},
mounted() {
console.log("Clock Object mounted!");
},
methods: {
add() {
this.money += Number(this.delta);
}
},
watch: {
money(newVal, oldVal) {
console.log("Money changed", newVal, oldVal);
}
}
};
</script>
#vue #vue.js #api #vue.js 3 #programming