My bucket has a folder “items/” where all my images go to. However, despite me accurately representing this in the key I am getting an error with the url generated when sending a post request to that url. The error mentions “The request signature we calculated does not match the signature you provided. Check your key and signing method.”

@Configuration
public class S3Config {

    @Value("${aws.region}")
    private String awsRegion;

    @Bean
    public S3Client s3Client() {
        S3Client client = S3Client.builder()
                .region(Region.of(awsRegion))
                .build();
        return client;
    }

    @Bean
    public S3Presigner s3Presigner() {
        return S3Presigner.builder()
                .region(Region.of(awsRegion))
                .credentialsProvider(DefaultCredentialsProvider.create())
                .build();
    }

}

@RestController
@RequestMapping("/s3")
public class S3Controller {

    private final S3Service s3Service;

    @Autowired
    public S3Controller(S3Service s3Service) {
        this.s3Service = s3Service;
    }

    // Endpoint to generate a presigned URL for PUT operations
    @GetMapping("/presign-put/{filename}")
    public ResponseEntity<String> getPresignedPutUrl(@PathVariable String filename) {
        try {
            String presignedUrl = s3Service.generatePresignedUrl(filename);
            return ResponseEntity.ok(presignedUrl);
        } catch (Exception e) {
            return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body("Failed to generate presigned URL: " + e.getMessage());
        }
    }
}

@Service
public class S3Service {
    private final S3Client s3;
    private final S3Presigner presigner;

    @Value("${aws.s3.bucketName}") //defined inside of application properties
    private String bucketName;

    public S3Service(S3Client s3, S3Presigner s3Presigner) {
        this.s3 = s3;
        this.presigner = s3Presigner;
    }

    public String generatePresignedUrl(String filename) {
        String key = "items/" + filename;
        PutObjectRequest putObjectRequest = PutObjectRequest.builder()
                .bucket(bucketName)
                .key(key)
                .build();

        PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder()
                .putObjectRequest(putObjectRequest)
                .signatureDuration(Duration.ofHours(24))
                .build();

        PresignedPutObjectRequest presignedRequest = presigner.presignPutObject(presignRequest);
        return presignedRequest.url().toString();
    }