httpsig 2.2.0: content-digest auto-coverage and verification enforcement - #69
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AAuth -11 Section 10.3 requires a request carrying a body to a PS or AS endpoint to cover content-digest (RFC 9530) and content-type on top of the four mandatory components. This package covered content-digest only when the caller listed it explicitly, and verified it only when the signer covered it -- so the rule was enforced nowhere, and the beta wallet hand-rolled the check. Signing side: after the covered components resolve, fetch() appends content-digest whenever the body's exact bytes are available to hash -- string, Uint8Array, ArrayBuffer, or Buffer, the four cases generateContentDigest handles. The component is NOT added to DEFAULT_COMPONENTS_BODY: a static list cannot know whether a given body is hashable, and putting it there would break every streaming caller. A new contentDigest option controls the behavior: 'auto' (default) appends when digestible, 'require' throws on a non-digestible body instead of silently dropping the component (what PS and AS callers pass), and 'omit' restores the pre-2.2 behavior. generateContentDigest now throws on body types it does not handle. Previously it fell through to String(body), so a ReadableStream produced a valid signature over the SHA-256 of the literal text "[object ReadableStream]" -- bytes that never go on the wire and that no verifier can reproduce. Without the throw, 'auto' could not tell "hashable" from "hashed the wrong thing". Verification side: a new VerifyOptions.requireContentDigest flag makes verification fail when the signature does not cover content-digest on a request with a body (the digest itself was already validated whenever covered). This is the flag a PS or AS sets to enforce Section 10.3. Resources are exempt from the profile rule and declare their needs via additional_signature_components in resource metadata. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01TQ2FCHHAnuJWF5TJB3838S
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Implements the AAuth -11 Section 10.3 HTTP Message Signatures profile rule: a request carrying a body to a PS or AS endpoint MUST cover
content-digest(RFC 9530) andcontent-typeon top of the four mandatory components. Resources are exempt and declare their needs viaadditional_signature_componentsin resource metadata.Signing (
fetch())content-digestis appended whenever the body's exact bytes are available to hash —string,Uint8Array,ArrayBuffer,Buffer, the four casesgenerateContentDigesthandles.ReadableStream,FormData, andBlobare serialized by the fetch implementation, so they are not digestible here.DEFAULT_COMPONENTS_BODYis deliberately unchanged: a static list cannot know whether a given body is hashable, and addingcontent-digestthere would break every streaming caller.contentDigest?: 'auto' | 'require' | 'omit'(default'auto'):'auto'— append when digestible, sign without it otherwise'require'— throw on a non-digestible body instead of silently dropping the component; PS and AS callers pass this'omit'— never auto-append (pre-2.2 behavior)generateContentDigestthrows on unhandled typesIt previously fell through to
String(body), so aReadableStreamproduced a valid signature over the SHA-256 of the literal text"[object ReadableStream]"— bytes that never go on the wire and that no verifier can reproduce. Without the throw,'auto'cannot tell "hashable" from "hashed the wrong thing".Verification (
verify())New
VerifyOptions.requireContentDigest?: boolean. When true, a request with a body fails verification (invalid_input, withrequired_inputnaming the full Section 10.3 body set) unless the signature coverscontent-digest; the digest itself was already validated whenever covered. This is the flag a PS or AS sets to enforce the rule instead of hand-rolling the check — the beta wallet hand-rolled exactly this.Tests
16 new tests in
httpsig/tests/test-content-digest.ts: auto-append for each digestible type, no append for ReadableStream/FormData/Blob under'auto','require'throwing on non-digestible bodies,'omit'behavior (including explicit listing still working),generateContentDigestequivalence across the four types and throwing on unhandled ones, andrequireContentDigestpass/fail/no-body/tampered-body on verify.npm test --workspace=httpsig: 190 pass, 0 fail (174 pre-existing + 16 new).better-auth(32) andemail-verification(120) suites also pass;npm run buildandnpm run lintclean.🤖 Generated with Claude Code
https://claude.ai/code/session_01TQ2FCHHAnuJWF5TJB3838S