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[S3] Metadata in POST policy is not returned

Open yohanleb opened this issue 5 months ago • 0 comments

Acknowledgements

  • [x] I have searched (https://github.com/aws/aws-sdk/issues?q=is%3Aissue) for past instances of this issue
  • [x] I have verified all of my SDK modules are up-to-date (you can perform a bulk update with go get -u github.com/aws/aws-sdk-go-v2/...)

Describe the bug

When creating a POST policy on the S3 bucket, I'd like to specify some metadata (x-amz-meta-*) as specified in the AWS docs. But when I specify, it is removed and not returned in the policy:

req := &s3.PutObjectInput{
	Bucket:        aws.String(a.BucketName),
	Key:           aws.String(path),
	ContentLength: aws.Int64(int64(size)),
	Expires:       aws.Time(time.Now().UTC().Add(15 * time.Minute)),
	Metadata: map[string]string{
		"field-1":   metadata["field-1"],
		"field-2":   metadata["field-2"],
		"field-3":   metadata["field-3"],
	},
}

presignedPost, err := a.presigner.PresignPostObject(context.Background(), req)

// presignedPost.Values doesn't contain the metadata (values are obfuscated)

// zap.L().Info("Presigned values", zap.Any("values", presignedPost.Values))
// {"level":"info","ts":1750604300.4369469,"caller":"storage/aws.go:81","msg":"Presigned values","values":{"X-Amz-Algorithm":"AWS4-HMAC-SHA256","X-Amz-Credential":"cred","X-Amz-Date":"20250622T145820Z","X-Amz-Signature":"signature","key":"key","policy":"policy"}}

I also tried to add custom conditions but I doubt this is the solution:

req := &s3.PutObjectInput{
	Bucket:        aws.String(a.BucketName),
	Key:           aws.String(path),
	ContentLength: aws.Int64(int64(size)),
	Expires:       aws.Time(time.Now().UTC().Add(15 * time.Minute)),
}

opts := func(o *s3.PresignPostOptions) {
	o.Conditions = []interface{}{
		map[string]string{
			"x-amz-meta-field-1":   metadata["field-1"],
			"x-amz-meta-field-2":   metadata["field-2"],
			"x-amz-meta-field-3":   metadata["field-3"],
		},
	}
}

presignedPost, err := a.presigner.PresignPostObject(context.Background(), req, opts)

Any assistance or guidance would be appreciated, thanks!

Regression Issue

  • [ ] Select this option if this issue appears to be a regression.

Expected Behavior

I would expect to see the metadata in the signature, for example:

{"x-amz-meta-field-1": "field 1", "x-amz-meta-field-3": "field 2", "x-amz-meta-field-3": "field 3"}

Current Behavior

Signature doesn't contain the metadata (values are obfuscated):

{"level":"info","ts":1750604300.4369469,"caller":"storage/aws.go:81","msg":"Presigned values","values":{"X-Amz-Algorithm":"AWS4-HMAC-SHA256","X-Amz-Credential":"cred","X-Amz-Date":"20250622T145820Z","X-Amz-Signature":"signature","key":"key","policy":"policy"}}

Reproduction Steps

Create a POST policy on an existing S3 bucket:

req := &s3.PutObjectInput{
	Bucket:        aws.String(a.BucketName),
	Key:           aws.String(path),
	ContentLength: aws.Int64(int64(size)),
	Expires:       aws.Time(time.Now().UTC().Add(15 * time.Minute)),
	Metadata: map[string]string{
		"field-1": metadata["field-1"],
		"field-2":   metadata["field-2"],
		"field-3":   metadata["field-3"],
	},
}

presignedPost, err := a.presigner.PresignPostObject(context.Background(), req)
zap.L().Info("Presigned values", zap.Any("values", presignedPost.Values))

Notice that the metadata is not returned by the policy.

Possible Solution

No response

Additional Information/Context

No response

AWS Go SDK V2 Module Versions Used

github.com/aws/[email protected] github.com/aws/[email protected]
github.com/aws/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/aws/protocol/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/aws/protocol/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/feature/ec2/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/feature/ec2/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/feature/ec2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/feature/ec2/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/feature/ec2/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/internal/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/aws/protocol/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] [email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/internal/endpoints/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/aws-sdk-go-v2/service/internal/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] github.com/aws/[email protected]
github.com/aws/aws-sdk-go-v2/service/[email protected] [email protected]

Compiler and Version used

go version go1.23.0 darwin/arm64

Operating System and version

MacOS Sequoia 15.3.1 (24D70)

yohanleb avatar Jun 22 '25 15:06 yohanleb