Add x-amz-expected-bucket-owner as a header the SDK needs to sign

[RanVaknin]

Adding the x-amz-expected-bucket-owner to the list of headers to sign.

Driver code:

package main

import (
	"fmt"
	"io"
	"net/http"
	"time"

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

func main() {
	sess, err := session.NewSession(&aws.Config{
		Region: aws.String("us-east-1"),
	})
	if err != nil {
		panic(err)
	}

	svc := s3.New(sess)

	req, _ := svc.GetObjectRequest(&s3.GetObjectInput{
		Bucket:              aws.String("bucket"),
		Key:                 aws.String("hey.txt"),
		ExpectedBucketOwner: aws.String("123456789123"),
	})

	str, err := req.Presign(60 * time.Minute)
	if err != nil {
		fmt.Println("Failed to sign request", err)
		return
	}

	fmt.Println("The presigned URL is:", str)

	request, err := http.NewRequest("GET", str, nil)
	if err != nil {
		panic(err)
	}

	request.Header.Add("host", "https://bucket.s3.amazonaws.com")
	request.Header.Add("x-amz-expected-bucket-owner", "123456789123")

	c := &http.Client{}
	res, err := c.Do(request)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	bod, err := io.ReadAll(res.Body)
	if err != nil {
		panic(err)
	}

	fmt.Println(res.Status, res.StatusCode)
	fmt.Printf("%s\n", bod)
}

Result before change:

The presigned URL is: https://bucket.s3.amazonaws.com/hey.txt?
X-Amz-Algorithm=AWS4-HMAC-SHA256&
X-Amz-Credential=REDACTED%2F20231109%2Fus-east-1%2Fs3%2Faws4_request&
X-Amz-Date=20231109T192709Z&
X-Amz-Expected-Bucket-Owner=123456789123&
X-Amz-Expires=3600&X-Amz-SignedHeaders=host&
X-Amz-Signature=REDACTED

400 Bad Request 400
<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>InvalidBucketOwnerAWSAccountID</Code><Message>Expected bucket owner must be provided as either a header or parameter, not both</Message><RequestId>REDACTED</RequestId><HostId>REDACTED</HostId></Error>

Result after change:

The presigned URL is: https://bucket.s3.amazonaws.com/hey.txt?
X-Amz-Algorithm=AWS4-HMAC-SHA256&
X-Amz-Credential=REDACTED%2F20231109%2Fus-east-1%2Fs3%2Faws4_request&
X-Amz-Date=20231109T192910Z&
X-Amz-Expires=3600&
X-Amz-SignedHeaders=host%3Bx-amz-expected-bucket-owner&
X-Amz-Signature=REDACTED
200 OK 200
hello