Accessing a S3 bucket through client code is denied - amazon-web-services

Question

I am trying to access and modify my s3 bucket through my web client. To do so, I've created a bucket and modified it in a way that it would allow public access.
My bucket policy:
{
"Version": "2012-10-17",
"Id": "Policy1646559824301",
"Statement": [
{
"Sid": "Stmt1646559821897",
"Effect": "Allow",
"Principal": "*",
"Action": "s3:GetObject",
"Resource": "arn:aws:s3:::airsoftarmory-user-inventory/*"
}
]}
My CORS setting:
[
{
"AllowedHeaders": [
"*"
],
"AllowedMethods": [
"PUT",
"HEAD",
"GET"
],
"AllowedOrigins": [
"*"
],
"ExposeHeaders": []
}]
ACL is enabled and looks like this:
For uploading an image to bucket, I created a new IAM user and a specific policy for putObject as follows:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "VisualEditor0",
"Effect": "Allow",
"Action": "s3:PutObject",
"Resource": "arn:aws:s3:::airsoftarmory-user-inventory/*"
}
]
}
Used access keys of this user with policy attached inside my code.
The problem is, I am getting access denied response while both uploading and downloading. Can someone help me, what am I missing?

Answer 1

For me to troubleshoot this problem.
I will check if aws has been configured properly. You could follow this guide, and could try aws sts get-caller-identity to check if credentials works properly.
The IAM role for the user is only given for PutObject, so this will not allow user to be able get any object out from the bucket. Try adding more permission to this user such as GetObject permission. This will give the user authority to pull out data from the bucket.
The bucket policy at the bucket only allow for GetObject and does not allow for any PutObject. Again try adding the PutObject action to the bucket policy. This might also be the problem facing now of not able to upload object to the bucket.
If you are confused with IAM and bucket policy. Try reading these blogs:
https://aws.amazon.com/blogs/security/iam-policies-and-bucket-policies-and-acls-oh-my-controlling-access-to-s3-resources/
https://binaryguy.tech/aws/s3/iam-policies-vs-s3-policies-vs-s3-bucket-acls/
Hope this helps!