---
phase: 25.1-parser-robustness-security-hardening
verified: 2026-03-13T00:30:00Z
status: passed
score: 9/9 must-haves verified
re_verification: null
gaps: []
human_verification:
  - test: "Run cargo +nightly fuzz run fuzz_ddl_parse -- fuzz/seeds/fuzz_ddl_parse/ -max_total_time=60"
    expected: "No panics or assertion failures found against the full detect + validate_and_rewrite pipeline on arbitrary byte sequences"
    why_human: "Requires nightly Rust toolchain; fuzz run cannot be verified in the CI environment without nightly"
---

# Phase 25.1: Parser Robustness and Security Hardening — Verification Report

**Phase Goal:** The DDL parser correctly handles all valid whitespace variants and is hardened against adversarial inputs.
**Verified:** 2026-03-13T00:30:00Z
**Status:** PASSED
**Re-verification:** No — initial verification

---

## Goal Achievement

### Observable Truths

| #  | Truth                                                                                     | Status     | Evidence                                                                 |
|----|-------------------------------------------------------------------------------------------|------------|--------------------------------------------------------------------------|
| 1  | `CREATE<tab>SEMANTIC<tab>VIEW v (...)` is detected and rewritten correctly                | VERIFIED   | `detect_ddl_kind` calls `detect_ddl_prefix` which uses `match_keyword_prefix`; all 7 DDL forms pass `prefix_whitespace_detection` proptest |
| 2  | `CREATE<newline>SEMANTIC<newline>VIEW v (...)` is detected and rewritten correctly        | VERIFIED   | `match_keyword_prefix` accepts any `is_ascii_whitespace()` between tokens; proptest covers `\n` in `[ \t\n\r]{1,4}` strategy |
| 3  | All 7 DDL forms work with arbitrary inter-keyword ASCII whitespace                        | VERIFIED   | `prefix_whitespace_detection` proptest covers all 7 forms (form_idx 0..7) with `arb_inter_keyword_ws`; `cargo test` passes (45 tests, 0 failed) |
| 4  | Error positions remain accurate after token-based prefix matching                        | VERIFIED   | `detect_ddl_prefix` returns consumed byte count; callers use `trim_offset + plen`; `position_invariant_*` proptests (TEST-03) still pass |
| 5  | TECH-DEBT.md item 4 is marked resolved                                                   | VERIFIED   | `TECH-DEBT.md` line 149: `### 4. ✅ DDL prefix whitespace — RESOLVED in Phase 25.1` |
| 6  | `cargo test` passes (all TEST-01 through TEST-08 green)                                  | VERIFIED   | Ran `cargo test`: "test result: ok. 45 passed; 0 failed" |
| 7  | `just test-all` passes                                                                    | VERIFIED   | Ran `just test-all`: "ALL PASSED" for Rust (310 tests), SQL logic tests (8 files), DuckLake CI, and caret-position integration tests |
| 8  | Adversarial inputs (1 MB input, null byte, semicolons, Unicode homoglyphs, control chars) cause no panics | VERIFIED | TEST-08 functions all pass: `test_large_input_no_panic`, `test_null_byte_in_name`, `test_semicolon_in_name`, `test_unicode_homoglyph`, `test_control_char_in_name` |
| 9  | Fuzz harness is in place and registered                                                   | VERIFIED   | `fuzz/fuzz_targets/fuzz_ddl_parse.rs` exists with correct libFuzzer structure; `fuzz/Cargo.toml` registers `fuzz_ddl_parse` [[bin]]; 5 corpus seeds in `fuzz/seeds/fuzz_ddl_parse/` |

**Score:** 9/9 truths verified

---

### Required Artifacts

#### Plan 01 Artifacts

| Artifact                                           | Expected                                                     | Status     | Details                                                                             |
|----------------------------------------------------|--------------------------------------------------------------|------------|-------------------------------------------------------------------------------------|
| `tests/parse_proptest.rs`                          | TEST-07 proptest block + TEST-08 adversarial unit tests      | VERIFIED   | Contains `arb_inter_keyword_ws`, `prefix_whitespace_detection`, `prefix_whitespace_rewrite_roundtrip`, and all 5 TEST-08 `#[test]` functions |
| `fuzz/fuzz_targets/fuzz_ddl_parse.rs`              | libFuzzer target exercising detect + validate_and_rewrite    | VERIFIED   | 33 lines; correct `#![no_main]` + `fuzz_target!(|data: &[u8]|...)` structure; calls `detect_semantic_view_ddl` then `validate_and_rewrite` |
| `fuzz/Cargo.toml`                                  | `fuzz_ddl_parse` [[bin]] registration                        | VERIFIED   | Line 34-35: `name = "fuzz_ddl_parse"`, `path = "fuzz_targets/fuzz_ddl_parse.rs"` |
| `fuzz/seeds/fuzz_ddl_parse/seed_basic.txt`         | Corpus seed: basic valid DDL (55 bytes)                      | VERIFIED   | File exists, 55 bytes                                                              |
| `fuzz/seeds/fuzz_ddl_parse/seed_tab_ws.txt`        | Corpus seed: tab-separated keywords (55 bytes)               | VERIFIED   | File exists, 55 bytes                                                              |
| `fuzz/seeds/fuzz_ddl_parse/seed_null_byte.txt`     | Corpus seed: null byte in name (59 bytes)                    | VERIFIED   | File exists, 59 bytes                                                              |
| `fuzz/seeds/fuzz_ddl_parse/seed_long.txt`          | Corpus seed: 200-char view name (254 bytes)                  | VERIFIED   | File exists, 254 bytes                                                              |
| `fuzz/seeds/fuzz_ddl_parse/seed_homoglyph.txt`     | Corpus seed: Cyrillic С prefix (56 bytes)                    | VERIFIED   | File exists, 56 bytes                                                              |

#### Plan 02 Artifacts

| Artifact       | Expected                                                                   | Status     | Details                                                                                      |
|----------------|----------------------------------------------------------------------------|------------|----------------------------------------------------------------------------------------------|
| `src/parse.rs` | `match_keyword_prefix` + `detect_ddl_prefix` helpers; `prefix_len` removed | VERIFIED   | 1904 lines; `match_keyword_prefix` at line 50; `detect_ddl_prefix` at line 86; no `prefix_len` function anywhere in file |
| `TECH-DEBT.md` | Item 4 marked `✅ DDL prefix whitespace — RESOLVED in Phase 25.1`          | VERIFIED   | Line 149 confirmed                                                                           |

---

### Key Link Verification

#### Plan 01 Key Links

| From                       | To           | Via                                          | Status     | Details                                                              |
|----------------------------|--------------|----------------------------------------------|------------|----------------------------------------------------------------------|
| `tests/parse_proptest.rs`  | `src/parse.rs` | `use semantic_views::parse::*`             | VERIFIED   | File uses `detect_ddl_kind`, `detect_semantic_view_ddl`, `validate_and_rewrite`, `PARSE_NOT_OURS`, `PARSE_DETECTED` |
| `fuzz/fuzz_targets/fuzz_ddl_parse.rs` | `src/parse.rs` | `semantic_views::parse::{detect_semantic_view_ddl, validate_and_rewrite, PARSE_DETECTED}` | VERIFIED | Line 3 of fuzz target imports all three symbols; both are called in the fuzz body |

#### Plan 02 Key Links

| From                        | To                   | Via                                            | Status     | Details                                                             |
|-----------------------------|----------------------|------------------------------------------------|------------|---------------------------------------------------------------------|
| `detect_ddl_kind`           | `detect_ddl_prefix`  | `detect_ddl_prefix(trimmed).map(|(kind, _)| kind)` | VERIFIED | Line 137 of `src/parse.rs`                                      |
| `rewrite_ddl`               | `detect_ddl_prefix`  | `let (kind, plen) = detect_ddl_prefix(trimmed)...` | VERIFIED | Line 262 of `src/parse.rs`                                      |
| `extract_ddl_name`          | `detect_ddl_prefix`  | `let (kind, plen) = detect_ddl_prefix(trimmed)...` | VERIFIED | Line 298 of `src/parse.rs`                                      |
| `validate_and_rewrite`      | `detect_ddl_prefix`  | `let Some((kind, plen)) = detect_ddl_prefix(trimmed_no_semi)` | VERIFIED | Line 606 of `src/parse.rs`                                |
| `parse_ddl_text`            | `detect_ddl_prefix`  | `let (kind, prefix_len) = detect_ddl_prefix(trimmed)...` | VERIFIED | Line 222 of `src/parse.rs`                                    |

---

### Requirements Coverage

Phase 25.1 has no formal requirement IDs. This is a cross-cutting quality concern.

Success criteria from ROADMAP.md are all satisfied:

| Success Criterion                                                                       | Status     | Evidence                                                                         |
|-----------------------------------------------------------------------------------------|------------|----------------------------------------------------------------------------------|
| SC-1: Token-based detection — `CREATE<tab>SEMANTIC<tab>VIEW` → `DdlKind::Create`        | SATISFIED  | `match_keyword_prefix` + `detect_ddl_prefix` in `src/parse.rs`; proptest GREEN  |
| SC-1: All 7 forms with tabs                                                             | SATISFIED  | `prefix_whitespace_detection` proptest covers all form indices 0..7              |
| SC-1: All 7 forms with newlines                                                         | SATISFIED  | `arb_inter_keyword_ws` strategy includes `\n`                                    |
| SC-1: All 7 forms with mixed whitespace                                                 | SATISFIED  | `[ \t\n\r]{1,4}` regex covers all 4 ASCII whitespace chars in combinations      |
| SC-2: `validate_and_rewrite` round-trips with non-space whitespace                     | SATISFIED  | `prefix_whitespace_rewrite_roundtrip` proptest GREEN                             |
| SC-3: Very long input (1 MB) — no panic, under 50 ms                                   | SATISFIED  | `test_large_input_no_panic` passes                                                |
| SC-3: Null byte in view name — clean error or Ok, no panic                             | SATISFIED  | `test_null_byte_in_name` passes                                                   |
| SC-3: Embedded semicolons in view name — safe output or error                          | SATISFIED  | `test_semicolon_in_name` passes                                                   |
| SC-3: Unicode homoglyphs — `PARSE_NOT_OURS`, no near-miss                              | SATISFIED  | `test_unicode_homoglyph` passes                                                   |
| SC-3: Control characters in view name — no panic                                       | SATISFIED  | `test_control_char_in_name` passes                                                |
| SC-3: Fuzz harness registered and corpus seeds committed                               | SATISFIED  | `fuzz_ddl_parse.rs` + `fuzz/Cargo.toml` + 5 seeds in `fuzz/seeds/fuzz_ddl_parse/` |
| SC-4: Body parser whitespace (carried over from Phase 25)                              | SATISFIED  | Pre-existing (Phase 25); no regression                                           |
| SC-5: Full suite — `just test-all` passes                                               | SATISFIED  | "ALL PASSED" for all test stages                                                 |

---

### Anti-Patterns Found

None found.

Scanned `src/parse.rs`, `tests/parse_proptest.rs`, `fuzz/fuzz_targets/fuzz_ddl_parse.rs`, and `TECH-DEBT.md` for:
- TODO/FIXME/PLACEHOLDER comments
- Empty implementations (`return null`, `return {}`, `return []`)
- Stub patterns (`console.log`, placeholder returns)

No issues detected. The `match_keyword_prefix` and `detect_ddl_prefix` functions are fully implemented with real logic (token scanning, case-insensitive matching, byte count accumulation). All 4 `prefix_len` call sites have been migrated and the static function was removed entirely.

---

### Human Verification Required

#### 1. Fuzz run under nightly toolchain

**Test:** `cargo +nightly fuzz run fuzz_ddl_parse -- fuzz/seeds/fuzz_ddl_parse/ -max_total_time=60`
**Expected:** No panics (`SIGABRT`), no assertion failures, no crashes. The fuzzer should exercise the full `detect_semantic_view_ddl` + `validate_and_rewrite` pipeline without finding any `panic!` or assertion violation.
**Why human:** Requires the nightly Rust toolchain (`cargo-fuzz` depends on it). Cannot be verified in the stable Rust CI environment. The harness structure, seed files, and `Cargo.toml` registration are fully verified — execution requires a human with nightly toolchain.

---

### Test Suite Results

| Suite           | Command           | Result        | Count           |
|-----------------|-------------------|---------------|-----------------|
| Rust unit+proptest | `cargo test`   | PASSED        | 45 tests (0 failed) |
| Rust nextest    | `just test-all` (nextest phase) | PASSED | 310 tests |
| SQL logic tests | `just test-sql`   | PASSED        | 8 test files    |
| DuckLake CI     | `just test-ducklake-ci` | PASSED | ALL PASSED |
| Caret position  | `uv run test/integration/test_caret_position.py` | PASSED | 3 tests |

---

### Deviations from Plan (Noted, Verified Acceptable)

**Seeds in `fuzz/seeds/` not `fuzz/corpus/`:** Plan 01 specified `fuzz/corpus/fuzz_ddl_parse/`. The implementation correctly placed seeds in `fuzz/seeds/fuzz_ddl_parse/` because the project `.gitignore` excludes `fuzz/corpus/`. This follows the project's established convention (`fuzz/seeds/fuzz_json_parse/`, `fuzz/seeds/fuzz_query_names/` etc.). Seeds are git-tracked and functional.

**`validate_and_rewrite` uses `trimmed_no_semi` for `detect_ddl_prefix`:** Plan 02 specified calling `detect_ddl_prefix` on the trimmed query. The implementation correctly passes `trimmed_no_semi` (already computed) so that the returned `plen` is relative to the trimmed start, preserving the `trim_offset + plen` error position arithmetic. Verified: `position_invariant_*` proptests (TEST-03) still pass.

---

## Summary

Phase 25.1 fully achieves its goal. The DDL parser now uses token-based keyword matching (`match_keyword_prefix` + `detect_ddl_prefix`) tolerating arbitrary ASCII whitespace between all 7 DDL prefix forms. The static `prefix_len()` function and its 4 call sites have been replaced with the dynamic byte count from `detect_ddl_prefix`. Five adversarial safety invariants are confirmed by `#[test]` functions. A libFuzzer harness with 5 corpus seeds is registered and ready to run under nightly. TECH-DEBT item 4 is closed. The full `just test-all` suite passes (310 Rust tests + SQL logic tests + DuckLake CI + caret-position integration tests).

---

_Verified: 2026-03-13T00:30:00Z_
_Verifier: Claude (gsd-verifier)_
