security: validate deserialized annotation data on load#58
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The sidecar (.comments.json) and crash-recovery draft (draft.json) are JSON files read back from disk that aren't always Quill's own well-formed output: they can be hand-edited, truncated by a crash, or — since the sidecar sits beside a potentially shared .md — supplied by another party. The editor trusts annotation positions structurally: a comment's from/to flow into doc.resolve, which throws on a negative, fractional, or NaN position, white-screening the app on open. normalizeSidecar previously validated nothing (comments: parsed.comments ?? []) and isValidDraft checked only the envelope, not the payload arrays. Either path could load a record that crashes the editor. - New utils/annotationValidation.ts is the single source of truth for "what a valid annotation looks like": sanitizeComments / sanitizeSuggestions drop non-array input and any record that fails the shape check, coercing every from/to to a finite non-negative integer (ordered from <= to) so it can't throw in the editor. sanitizeAISession is all-or-nothing (a partial binding can't resume a conversation). - normalizeSidecar and the draft loader both route through it, so the two deserialization boundaries enforce identical guarantees. A malformed record is dropped, not fatal — recoverable data still loads. Adds a 30-case unit suite for the validators (bad positions, wrong types, mixed good/bad arrays, partial bindings). Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Documents Quill's security posture for a reviewing engineer: the threat model (deep link as the one attacker-influenced entry point; deserialized data trusted more than rendered data), the four merged hardening measures (#57 path confinement + deep-link validation, #58 annotation sanitization, #59 URL scheme allowlists, #60 binary-resolution hardening), and the two deliberate non-fixes left in place with rationale (asset-protocol $HOME/** scope, remote-image beacon). Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>
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What
Closes the gap where Quill trusted deserialized data far more than rendered data. The sidecar (
.comments.json) and crash-recovery draft (draft.json) are JSON read back from disk — not always Quill's own well-formed output. They can be hand-edited, truncated by the crash they exist to recover from, or (the sidecar sits beside a potentially shared.md) supplied by someone else.The editor trusts annotation positions structurally: a comment's
from/toflow intodoc.resolve, which throws on a negative, fractional, orNaNposition — white-screening the app on open.normalizeSidecarpreviously validated nothing (comments: parsed.comments ?? []) and the draft loader checked only the envelope, not the payload arrays.Changes
src/utils/annotationValidation.ts— one source of truth for "what a valid annotation looks like."sanitizeComments/sanitizeSuggestionsdrop non-array input and any record that fails the shape check, coercing everyfrom/toto a finite non-negative integer (orderedfrom <= to) so it can never throw in the editor.sanitizeAISessionis all-or-nothing — a partial binding can't resume a conversation and would only mislead the UI.normalizeSidecarand the draft loader both route through it, so the two deserialization boundaries enforce identical guarantees. A malformed record is dropped, not fatal — genuine recoverable data still loads.Tests
30-case unit suite for the validators (bad/negative/NaN/fractional positions, wrong types, mixed good-and-bad arrays, partial bindings, default coercion). Full bar green: typecheck, eslint, prettier, vitest (250, +19).
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