Package org.springframework.ai.bedrock.converse.api

Class MediaFetcher

java.lang.Object
org.springframework.ai.bedrock.converse.api.MediaFetcher
public final class MediaFetcher extends Object
Fetches media content from HTTP/HTTPS URLs with SSRF and resource-exhaustion protections.

Protection measures:

  • Socket-level blocking via MediaFetcher.SsrfBlockingPlainSocketFactory and MediaFetcher.SsrfBlockingSSLSocketFactory: the resolved InetAddress is checked at connectSocket() time — after DNS resolution — so raw IP literals (e.g. 127.0.0.1, 169.254.169.254) are blocked even when no DNS lookup occurs.
  • DNS-level blocking via MediaFetcher.SsrfSafeDnsResolver: hostnames that resolve to internal addresses are rejected early, before a connection attempt is made. This provides a fast-fail path for hostname-based requests and limits DNS rebinding exposure.
  • HTTP redirects are disabled to prevent redirect chains that lead to internal addresses.
  • Connect and socket timeouts prevent slow-server resource exhaustion.
  • Response bodies are capped at 41943040 bytes to prevent memory exhaustion.
Since:
1.0.0
Author:
Christian Tzolov

  • Field Details

    • DEFAULT_MAX_FETCH_SIZE_BYTES

      public static final int DEFAULT_MAX_FETCH_SIZE_BYTES
      Maximum number of bytes fetched from a media URL. Protects against memory exhaustion when a user-supplied URL points to arbitrarily large content (40 MB).
      See Also:

  • Constructor Details

    • MediaFetcher

      public MediaFetcher()
      Creates a MediaFetcher with no host allowlist (blocklist-only protection).

    • MediaFetcher

      public MediaFetcher(Set<String> allowedHosts)
      Creates a MediaFetcher with an optional host allowlist.

      When allowedHosts is non-empty, every fetch is checked against this set before the SSRF blocklist. A host is allowed when it either equals an entry exactly (case-insensitive) or matches a wildcard entry of the form *.example.com.

      Parameters:
      allowedHosts - set of permitted hostnames or wildcard patterns; an empty set disables allowlist enforcement

  • Method Details

    • fetch

      public byte[] fetch(URI uri)
      Fetches the content at uri and returns it as a byte array.

      The caller is responsible for validating the URI (protocol, host) before invoking this method. This method enforces size limits and socket-level SSRF protection.

      Parameters:
      uri - the URI to fetch
      Returns:
      the response body as a byte array
      Throws:
      SecurityException - if the response exceeds DEFAULT_MAX_FETCH_SIZE_BYTES or the host resolves to a blocked internal address
      org.springframework.web.client.RestClientException - on HTTP or I/O errors