Spring: What parser to use to parse security expressions - spring-security

I would like to parse standard security expressions like hasRole etc. to get their value in a variable (in a JSP). How can I do that? SpelExpressionParser is the standard EL parser, but I don't think it will parse the security expression.

The simpliest approach is to use a <sec:authorize> tag and modify a desired variable inside its body.
If you actually want to evaluate expressions manually, look at the source of AuthorizeTag - it gets the first bean of type WebSecurtyExpressionHandler from the web application context and uses it to obtain ExpressionParser and EvaluationContext.

I've posted an answer in this topic here - How to parse spring security expressions programmatically. I think this answers your question also.

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Where can I see the specification for thymeleaf th:method?

I've seen a lot of answers about how to send PUT/DELETE/PATCH HTTP requests with thymeleaf, and it's by using th:method = "the_specific_method", but i haven't found the thymeleaf specification about that. Can anyone help showing me where is it?
Thanks in advance.
I've tried to google for the answer, but no luck.
th:method isn't special to Thymeleaf -- it's just like any other plain old attribute which will output the result of an expression to the method attribute. It doesn't do (or care about) anything else. You can put any string and/or string expression into it, and Thymeleaf will happily output it.
th:method="${'the_specific_method'}"
will output
method="the_specific_method"
without regards to whether or not it's valid. If you want to learn about the method attribute, you just need to learn about how method works in plain old regular html and how browsers (and/or Spring) work with it.

Accept/Content-Type header based processing in Quart and Quart-Schema

Because I am rewriting a legacy app, I cannot change what the clients either send or accept. I have to accept and return JSON, HTML, and an in-house XML-like serialization.
They do, fortunately set headers that describe what they are sending and what they accept.
So right now, what I do is have a decoder module and an encoder module with methods that are basically if/elif/else chains. When a route is ready to process/return something, I call the decoder/encoder module with the python object and the header field, which returns the formatted object as a string and the route processes the result or returns Response().
I am wondering if there is a more Quart native way of doing this.
I'm also trying to figure out how to make this work with Quart-Schema. I see from the docs that one can do app.json_encoder = <class> and I suppose I could sub in a different processor there, but it seems application global, there's no way to set it based on what the client sends. Optimally, it would be great if I could just pass the results of a dynamically chosen parser to Quart-Schema and let it do it's thing on python objects.
Thoughts and suggestions welcome. Thanks!
You can write your own decorator like the quart-schema #validation_headers(). Inside the decorator, check the header for the Content-Type, parse it, and pass the parsed object to the func(...).

Why use "?" instead of ":" in URL?

We can use
'PATCH /companies/:id' : 'CompanyController.find'
to update data.
One suggested me that I can use the alternative way:
'PATCH /companies/find?key=Value'
But I do not know what it works. Please explain me why we prefer ? mark than : mark in search path.
You can use either or. The biggest reason most people chose one or the other is just how they want to present the URL to the user.
Using a path variable (:) can symbolize you're accessing a defined resource, like a user ID, where as an argument (?) can symbolize you're are dynamically changing/searching something within a defined resource, like a token or search term.
From what I can tell that's the general practice I see:
example.com/user/:username
versus
example.com/user/?search="foo"
http://en.wikipedia.org/wiki/URL
If we are firing GET request, ? symbol is used to let the server know the url parameter variables starts from there. And this is commonly used. I didn't used : symbol instead of ?
You are probably messing the things up:
According to your example, :id indicates a variable that must me replaced by an actual value in some frameworks such as Express. See the documentation for details.
And ? indicates the beginning of the query string component according to the RFC 3986.
It's a rule to design rest api
you can find 'how to design a rest api'
Assuming below code is Sails.js
'PATCH /companies/:id' : 'CompanyController.find'
It will makes REST API that be mapped onto 'CompanyController.find' by using PathParam. Like this
www.example.com/companies/100
Second one will makes REST API by using QueryParam.
It also be mapped onto 'CompanyController.find'
/companies/find?key=Value
But the API format is different. Like this
www.example.com/companies/find?key=100
PathParam or QueryParam is fine to make REST API.
If the Key is primary for company entity,
I think PathParam is more proper than QueryParam.

When do I need to encode with multiple codecs in Grails?

I'm not clear of when (or if) I should use multiple Grails encodeAsXXX calls.
This reference says you need to encodeAsURL and then encodeAsJavaScript: http://grailsrocks.com/blog/2013/4/19/can-i-pwn-your-grails-application
It also says you need to encodeAsURL and then encodeAsHTML, I don't understand why this is necessary in the case shown but not all the time?
Are there other cases I should me using multiple chained encoders?
If I'm rendering a URL to a HTML attribute should I encodeAsURL then encodeAsHTML?
If I'm rendering a URL to a JavaScript variable sent as part of a HTML document (via a SCRIPT element) should I encodeAsURL, encodeAsJavaScript then encodeAsHTML?
If I'm rendering a string to a JavaScript variable sent as part of a HTML document should I encodeAsJavaScript then encodeAsHTML?
The official docs - https://docs.grails.org/latest/guide/security.html - don't show any examples of multiple chained encoders.
I can't see how I can understand what to do here except by finding the source for all the encoders and looking at what they encode and what's valid on the receiving end - but I figure it shouldn't be that hard for a developer and there is probably something simple I'm missing or some instructions I haven't found.
FWIW, I think the encoders I'm talking about are these ones:
https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/web/util/JavaScriptUtils.html#javaScriptEscape-java.lang.String-
https://docs.oracle.com/javase/7/docs/api/java/net/URLEncoder.html#encode(java.lang.String,%20java.lang.String)
https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/util/HtmlUtils.html#htmlEscape-java.lang.String-
.
It is certainly important to always consider XSS but in reading your question I think you are overestimating what you need to do. As long as you're using Grails 2.3 or higher and your grails.views.default.codec is set to html which it will be by default, everything rendered in your GSP with ${} will be escaped properly for you.
It is only when you are intentionally bypassing the escaping, such as if you need to get sanitized user input back into valid JavaScript within your GSP for some reason, that you would need to use the encodeAsXXX methods or similar.
I would argue (and the article makes a mention of this as well) that this should raise a smell anyway, as you probably should have that JavaScript encapsulated in a different file or TagLib where the escaping is handled.
Bottom line, use the encoding methods only if you are overriding the default HTML encoding, otherwise ${} handles it for you.

Can I indicate a regular expression requirement for a parameter value using Swagger?

In my REST API, one of the submitted parameter values must be a code following the regex:
/[A-Z]{2}[0-9]{4}/
Is there any way, besides putting it in the description property of the parameter, for me to indicate that the value is not valid if it does not match my regular expression?
I was not able to find any mention of regex's in the Swagger doc, except as a way to identify Patterned Fields (which is not what I want to do).
You can use a field named pattern in your api's parameters if is not a body or in your scheme definitions for properties, it use standard ECMA 262 : (http://json-schema.org/latest/json-schema-validation.html#rfc.section.3.3)
[UPDATE Jul. 2019]
OpenAPI 3 spec -
https://swagger.io/docs/specification/data-models/data-types/#pattern

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