Example of S3 upload using STS

[lon9man]

Before opening, please confirm:

• I have searched for duplicate or closed issues and discussions.

Language and Async Model

Kotlin - Coroutines

Amplify Categories

Authentication, Storage

Gradle script dependencies

Environment information

Please include any relevant guides or documentation you're referencing

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Describe the feature request

Hello, team.
we need general guidance for the simplest example in the world.

we have:

1. PHP API backend. it implements login-functionality
2. android mobile application (and swift application also)
3. AWS infrastructure

we need to implement:

upload to S3 from mobile apps

basic flow:

a) user logins using PHP API backend on mobile app. receives auth TOKEN back
b) user chooses file and presses button Upload

so to implement upload we should use for example Amplify.
BUT WITHOUT ANY COMPLEX WRAPPERS like Cognito, Sign-In with Apple, Sign-In with Amazon, Sign-In with Facebook and etc. we don't want to have user database on AWS or sync it there from PHP backend.

as far as i feel it is possible to make using STS. saying mobile app receives from PHP API backend temporary STS-token and will use it to call AWS. BUT i don't see how this STS can be injected into Amplify?

questions:

1. what is SEVERAL possible approaches to implement this on simplest manner using our architecture?
2. how to inject STS token into Amplify Storage and other services?

thanks!

Initialization steps (if applicable)

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Code Snippet

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amplifyconfiguration.json

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GraphQL Schema

Additional information and screenshots

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[mattcreaser]

Hi @lon9man - this (providing custom/non-cognito credentials) is not currently supported in the Amplify Storage category. I'll mark this issue as a feature request for this library.

That being said, it should be possible to use STS credentials by directly using the lower-level AWS SDK for Kotlin.

I can't give you in-depth support for the AWS SDK, but I believe that what you want to do is something like the following:

1. Create a StaticCredentialsProvider with the credentials available from your service.
2. Instantiate an S3Client and pass your credentials provider.
3. Use the S3Client to upload your file.

If you have any issues or further questions about this I'd recommend posting a discussion question in the AWS SDK for Kotlin repository. Hope that helps!