https://github.com/nfour/urn-schema
URN Schema Validator
https://github.com/nfour/urn-schema
Last synced: over 1 year ago
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URN Schema Validator
- Host: GitHub
- URL: https://github.com/nfour/urn-schema
- Owner: nfour
- Created: 2016-08-01T08:08:48.000Z (almost 10 years ago)
- Default Branch: master
- Last Pushed: 2016-08-06T23:50:38.000Z (almost 10 years ago)
- Last Synced: 2024-10-11T23:18:40.977Z (almost 2 years ago)
- Language: JavaScript
- Homepage:
- Size: 22.5 KB
- Stars: 0
- Watchers: 4
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
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README
# URN Schema
This library handles URN schemas, similar to AWS ARN's, useful for access control.
Features:
- [x] Variable interpolation `urn:${some.dataset}`
- [x] Wildcarding `urn:*`
- [x] Precompilation for performance
- [x] Uri validation `urn:this/${is.a}/*/uri?with&a&query`
- [x] ACL's
- [x] Conforms to [URN](https://en.wikipedia.org/wiki/Uniform_Resource_Name)
```js
import UrnSchema, { UriValidator } from 'urn-schema'
const schema = new UrnSchema('version:method:scope:uri', {
uri: UriValidator,
})
const acl = schema.createAcl({
group_a: [
"urn:1.0:POST:testing:products/*/items/*"
]
})
acl.validate('group_a', {
version : '1.0',
method : 'POST',
scope : 'testing',
uri : 'products/22/items'
}) // returns { valid: true, group: 'group_a' }
acl.validate('group_a', {
version : '2.0',
method : 'GET',
scope : 'testing',
uri : 'products/22/items'
}) // returns { valid: false, group: 'group_a' }
```
In the basic example above we have defined a schema which matches predefined properties, including parsing the `uri` appropriately.
Below is a more advanced example.
```js
const acl = schema.createAcl({
group_a: [
"urn:${versions}:GET:${scopes}:products/${user['!~validIds~!']}/*?direction&order"
]
})
const data = {
versions: [ '1.0', '2.0' ],
scopes: [ 'testing', 'staging' ],
user: {
"!~validIds~!": [ 22, 24, 77 ]
}
}
acl.validate('group_a', {
version : '2.0',
method : 'GET',
scope : 'testing',
uri : 'products/22/items?order=size'
}, data) // returns { valid: true, group: 'group_a' }
```
In the above example the variables defined in `group_a`'s first urn are interpolated from the `data` object.
These uri's would also pass:
- `products/24/`
- `products/27/something?direction=asc`
And so too would version `1.0` and scope `staging`.
It's easy to parse a full URL into something you can use against the schema.
Imagine the below `originalUrl` is `/2.0/testing/products/22`.
```js
app.use((req, res, next) => {
const { method, originalUrl, auth } = req
// Take off the first 2 parts
let [ version, scope, ...uri ] = originalUrl
.replace(/^\/|\/$/g, '') // Remove trailing & leading slashes
.split('/')
uri = uri.join('/') // Join it back up
const aclCheck = acl.validate(auth.scope, {
version, scope, method, uri
})
if ( aclCheck.valid )
return next()
return next( new ForbiddenError("Permission denied!!!") )
})
```
### Interpolation Mechanics
When a variable is interpolated, the type matters.
- If `${some.data}` resolves to an array `[1, 2]`, then the value can match either of them, as a string comparison
- If `${some.data}` resolves to any other type, it will be stringified and compared against the value