Create 2025-04-02-data-validation-in-juno-best-practices-and-security #373
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Added a draft for an article on proper data validation in Juno. - Functions still need some work and better comments. - Maybe needs an image somewhere, but what to use here? - it is a bit long, maybe cut out the longer examples and additional resources at the end.
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| # Data Validation in Juno: Best Practices and Security | ||
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| ## Why Data Validation Matters in Decentralized Apps |
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suggestion: Data validation matters regardless of the type of app and environment, so I would suggest a more generic introduction here.
| if user_data.username.len() < 3 { | ||
| // Step 3: If validation fails, delete the document | ||
| delete_doc( | ||
| String::from("users"), |
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What's String::from("users")? I guess here you want to use ic_cdk::id() instead (the principal of the Satellite which itself is considered as an administrator since the code runs on the backend)
| } | ||
| ).await?; | ||
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| return Err("Username must be at least 3 characters".to_string()); |
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If you return an error, the hook will trap. If it traps, all changes will be reverted and therefore your delete_doc won't have any effect. If you want to log and commit the deletation you should:
ic_cdk::print("Username must be at least 3 characters");
return Ok(())
or just omit the return.
| **Issues:** | ||
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| - Only executes AFTER data is already written to the database, which is not ideal for validation. | ||
| - Can trigger cascading effects if not carefully managed |
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What casciding effects do you foreseen?
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| Custom Endpoints are Juno serverless functions that expose new API endpoints through Candid (the Internet Computer's interface description language). They provide a validation layer through custom API routes before data reaches Juno's datastore, allowing for complex multi-step operations with custom validation logic. | ||
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| ```rust |
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I'm not sure what you are providing snippets for assert_set_doc and on_set_doc in this particular chapter.
| } | ||
| ``` | ||
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| ### on_set_doc Example |
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To shorten a bit the blog post and given that assert_set_doc is the way to go, I suggest to remove this on_set_doc and custom end point examples.
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| Remember: Security is about preventing unauthorized or invalid operations, not just making them difficult. assert_set_doc hooks provide the only guaranteed way to validate all data operations in Juno's Datastore. | ||
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| ## Reference: Available Juno Hooks and Context Types |
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I would remove the references because they duplicate their docs, for maintanability reason as we are publishign this post on the website.
| }; | ||
| ``` | ||
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| ### Hook Types and Use Cases |
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Same, I would remove this chapter
| - `assert_upload_asset`: Confirms an asset upload can be committed | ||
| - `assert_delete_asset`: Checks that an asset can be deleted | ||
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| ### Feature Selection |
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Same, I would remove this chapter
| junobuild-satellite = { version = "0.0.21", default-features = false, features = ["on_set_doc", "assert_set_doc"] } | ||
| ``` | ||
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| ### Best Practices |
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Same, I would remove this chapter
Added a draft for an article on proper data validation in Juno.