fix s3 expected bucket owner presigning

[lucix-aws]

Tested:

package main

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"net/url"

	"github.com/aws/aws-sdk-go-v2/aws"
	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/s3"
)

func main() {
	cfg, err := config.LoadDefaultConfig(context.Background())
	if err != nil {
		panic(err)
	}

	svc := s3.NewFromConfig(cfg)
	presigner := s3.NewPresignClient(svc)
	u, err := presigner.PresignGetObject(context.Background(), &s3.GetObjectInput{
		Bucket:              aws.String("<...>"),
		Key:                 aws.String("<...>"),
		ExpectedBucketOwner: aws.String("<... an account id number that isn't expected>"),
	})
	if err != nil {
		panic(err)
	}

	println(u.URL)
	fmt.Printf("%#v\n", u.SignedHeader)

	uu, _ := url.Parse(u.URL)
	resp, err := http.DefaultClient.Do(&http.Request{
		URL:    uu,
		Header: u.SignedHeader,
	})
	if err != nil {
		panic(err)
	}
	fmt.Println(resp.Status)
	p, _ := io.ReadAll(resp.Body)
	fmt.Println(string(p))
}

with fix the presigned GET response printed is the expected 403.

[Madrigal]

love this comment <3