{"version":"2.1.268","anchor":"s3-tool-gains-explicit-deny-by-default-policy-fields-for-aws","canonical_anchor":"new-aws-sigv4-masked-credential-signing-policy-default-deny","heading":"AWS request signing now defaults to deny for unre-signable request types","tier":"use","area":"S3 Tool","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.268\/e\/s3-tool-gains-explicit-deny-by-default-policy-fields-for-aws","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.268","markdown":"### AWS request signing now defaults to deny for unre-signable request types\n\nRequests using AWS streaming uploads, presigned URLs, or SigV4A signatures are now blocked by default unless explicitly allowed\n\n**What**\n\nA new policy schema governs how Claude Code's credential-masking proxy handles AWS requests it cannot fully re-sign itself, covering three categories:\n\n- `streaming` \u2013 AWS-chunked streaming uploads\n\n- `presigned` \u2013 URLs with an embedded signature\n\n- `sigv4a` \u2013 requests using asymmetric SigV4A signatures\n\nEach of these now defaults to `\"deny\"` (the request fails closed with a 403 error) unless explicitly set to `\"passthrough\"`. This replaces old vendor code that previously implemented an unrelated JSON-schema `$recursiveAnchor` keyword at this same location.\n\n**Why**\n\nThese request types can't be safely re-signed by the masking proxy, so letting them through by default would risk exposing real credentials. Defaulting to deny closes that gap while still allowing an explicit opt-in via passthrough where it's known to be safe.\n\n- Area: S3 Tool\n- Names: `streaming`, `presigned`, `sigv4a`\n- Tier: Use it now\n- Useful: 4\/5\n- Signal: 3\/5"}