Claude can use a secret without seeing it: a masked box saves keys to .env and gives Claude a placeholder, every key a tool prints comes back as a placeholder…

A Claude Code mod that lets Claude use a secret without ever seeing it. When Claude needs an API key, it calls a request_secret tool, a masked box opens, you paste the key, and the mod writes it to .env. Claude gets a placeholder like [REDACTED-SECRET-3f9a1c2e] instead of the value, and the placeholder turns into the real key whenever a tool runs. Any key a tool prints comes back to Claude as a placeholder, and committing .env is refused.

A key that reaches the conversation is in the transcript for good. It is sent to the model on every turn after, kept in the session file on disk, and replayed into every fork of the session. You can't take it back afterwards, so the only fix is to never send it. Keys get in two ways: you paste one, or a tool prints one (a cat .env, a config file, an API answer). secret-box closes both, and still lets Claude run the code that needs the key.
request_secret takes a variable name and a one-line reason. Its description tells Claude to use it instead of asking you to paste.NAME=value to .env (and makes sure .gitignore covers it), then tells Claude the name and a placeholder. Claude can put the placeholder in a command or a file: curl -u [REDACTED-SECRET-3f9a1c2e]: https://api.stripe.com/v1/balance runs with the real key.sk_live_, ghp_, AKIA, xoxb- and more), any key shaped like a short lowercase prefix and a long random body (imp_ and 40 hex), passwords on CLI flags and in connection strings, base64 that decodes to a key, high-entropy tokens, every .env value with a secret name, and every value the mod already knows come back as placeholders. cat .env still shows PORT=3000.git add .env and a git commit that would carry a .env file are refused, because a pushed key can't be taken back.

claude plugin marketplace add ray-amjad/claude-code-mods
claude plugin install secret-box@claude-code-mods
Or inside Claude Code: /plugin marketplace add ray-amjad/claude-code-mods, then /plugin install secret-box@claude-code-mods.
Ask for something that needs a secret, such as billing.js needs the Stripe secret key, get it set up. Claude calls secret-box - request_secret.
Then ask Claude to use it: check the key works. It writes the placeholder into a command and the real key is used. A tool row says secret-box: hid 1 value(s) whenever something was swapped on the way out.
If you'd rather not wait for Claude to think of the tool, say use the secret box to ask me for STRIPE_SECRET_KEY.
The example folder is a tiny app whose billing.js reads STRIPE_SECRET_KEY, with a .env.example beside it.
cp -R example /tmp/shop && cd /tmp/shop && git init
claude
Accept the trust prompt (mods don't load in an untrusted folder). Tell Claude billing.js needs the Stripe secret key, paste a fake key such as sk_test_123, and press Enter. Then ask prove the key is in .env without showing it to me, and cat .env to see the placeholder.
Set them with /plugin configure secret-box@claude-code-mods, or under pluginConfigs in your user settings.
| Option | Default | What it does | | :- | :- | :- | | secrets | true | Hide secrets in tool output and prompts | | pii | false | Hide email addresses and public IP addresses | | hideEmails | true | With pii on, also hide emails; turn off to hide only IPs | | redactPrivateIps | false | With pii on, also hide private and reserved IPs recognized by the detector | | restoreInToolInputs | true | Turn placeholders back into real values before a tool runs | | restoreTools | Bash,Write,Edit,MultiEdit,NotebookEdit | The tools that may receive a real value. Tools that send data off the machine are left out on purpose | | notify | true | A count on the tool row, a toast on a prompt | | minEntropy | 3.6 | Bits per character for the high-entropy test | | minLength | 24 | Shortest token the high-entropy test looks at | | contextMinEntropy | 3.0 | The floor when API_KEY=, "token": or Bearer sits in front | | allow | empty | Exact strings never to hide, comma separated | | allowEmails | empty | Addresses or @domain.com never to hide | | allowPrefixes | empty | Extra id prefixes to treat as public | | denyPrefixes | empty | Prefixes to test even though they look like a public id |
Stripe object ids (price_, prod_, cus_, pk_live_ and so on) are public and are never hidden. Neither are git SHAs, file paths or names written in code.
session.start registers the tool with isDeferred: false, so Claude sees it on every turn, and reads .env in the working directory to learn which values are secret.$.ui.open and an Input. The element has no password mode, so the mod masks it itself: the field draws • repeated, and onInput works out what was typed, pasted or deleted and keeps the real value in a module variable. A hook may only run for 10 seconds of its own time, but time inside a mods API call doesn't count, so it waits for you in short $.process.run(['sleep', '0.3']) calls..env with $.fs and hands the value to the vault, which answers with the placeholder. The vault maps each value to a random placeholder that stays stable within the session, and lives in memory only.hooks/redact.ts and hooks/detect.ts. register.jsx calls its register and adds only what secret-box needs, so the two can't drift. Its hooks hide keys in your prompt, CLAUDE.md, tool results, @ files, the engine's own attachments and subagent tasks, and put real values back into Bash, Write and Edit. A value restored into a command is hidden again if the command prints it..env file, a tool.call hook reads it too and gives every value whose name says secret (KEY, TOKEN, SECRET, PASSWORD and the like) to the vault. So even a weak value the detector would miss, like a word password, comes back as a placeholder.tool.call hook on Bash refuses git add of a .env file and runs git diff --cached --name-only before any git commit. A prompt.mention hook refuses @.env, which would attach the raw file..catch that fails closed: if a scan breaks, the output is withheld or the call is refused.base64, rev) or sends it somewhere, and the transformed output isn't recognized. This stops keys from landing in the transcript by accident. It is not a sandbox against a model that is trying to leak one.cat .env and source .env as credential access before secret-box sees them. Using the placeholder from the box still works. In default mode, approve the read and it comes back masked.git commit or gh issue, gh pr (and the like) gets no real values, so a commit message keeps the placeholder. A step that needs the key has to be its own command.Write or Edit lands on disk as the key..env value under 8 characters is hidden in .env reads, but not wherever else it turns up..env at the start of each session, so those values are hidden again..env is learned at session start. Other .env files are masked by name when they are read.claude -p has no one to type, so the tool answers that it needs an interactive session.claude --plugin-dir ./secret-box
claude plugin validate .
claude plugin test .
node --experimental-strip-types tests/detect.test.mts
tests/secret-box.test.ts covers the guard, .env values and the round trip from placeholder to value. tests/detect.test.mts is transcript-redactor's detector test: 174 values that must be hidden and 114 that must be kept.
Tested with Claude Code 2.1.296.
Random placeholder tags were contributed by Ben Ellis (@benissimo). The hideEmails option was contributed by Cody Harris (@VibeCodyH). Both implementations are adapted to this mod's current vault and hooks.
To keep emails readable while hiding public IPs, set pii: true and hideEmails: false. PII hiding remains off by default. The restored IP detector recognizes IPv4 and full-form IPv6; compressed IPv6 is not comprehensively covered.
hooks/register.jsx 270 lines1// secret-box: Claude can use a secret without ever seeing it.
2//
3// Pattern: guard what you can't undo. A secret in the conversation is in the
4// transcript for good, so it must never get there:
5// - In: Claude calls request_secret, you paste the value into a masked box,
6// the mod writes it to .env and hands Claude a placeholder.
7// - Out: every secret a tool would show Claude (a `cat .env`, an API answer,
8// a key you paste) is swapped for a placeholder like [REDACTED-SECRET-1a2b3c4d].
9// - Use: a placeholder in a tool's input becomes the real value as the tool
10// runs, so `curl -H "Authorization: Bearer [REDACTED-SECRET-...]"` works.
11// - Never: committing .env is refused, since a pushed key can't be taken back.
12//
13// The redaction is transcript-redactor, unchanged (./redact.ts, ./detect.ts):
14// its hooks do the In, Out and Use. This file adds the box, teaches the vault
15// the values in .env, and guards commits. Nothing is written but .env.
16
17import { register as redactor, LIVE_TAG_TOOLS, brand } from './redact.ts'
18import { keepSecret } from './detect.ts'
19
20const TOOL = 'mcp__secret-box__request_secret'
21const PANE = 'secret-box'
22const DOT = '•'
23
24// The one request being collected right now. The real value lives only here,
25// in the mod's memory, until it is saved.
26let pending = null // { name, reason, value, answer, isInBand }
27
28// A .env key whose name says it holds a secret
29const SECRET_NAME = /KEY|TOKEN|SECRET|PASS|PWD|CREDENTIAL|AUTH|PRIVATE|DSN|SALT|SIGNING|WEBHOOK/i
30const ASSIGNMENT = /^(\s*(?:export\s+)?([A-Za-z_][A-Za-z0-9_]*)\s*=\s*)(.*)$/gm
31
32export function register(on, options) {
33 // request_secret answers with a live placeholder: keep it live
34 LIVE_TAG_TOOLS.add(TOOL)
35 brand.name = 'secret-box'
36 redactor(on, options || {})
37
38 // 1. Give Claude the tool, and teach the vault the secrets already in .env
39 on('session.start', async ($, e, next) => {
40 await $.tool.register({
41 name: 'request_secret',
42 description:
43 'Ask the user for a secret (API key, token, password) without it ever entering the conversation. ' +
44 'The user pastes it into a masked box and the mod saves it to the project .env. You get back the ' +
45 'variable name and a placeholder like [REDACTED-SECRET-1a2b3c4d]. Write that placeholder in a command ' +
46 'or file and it becomes the real value when the tool runs. Use this INSTEAD of asking the user to ' +
47 'paste a secret into chat.',
48 inputSchema: {
49 type: 'object',
50 properties: {
51 name: { type: 'string', description: 'Environment variable name, e.g. STRIPE_SECRET_KEY' },
52 reason: { type: 'string', description: 'One short line telling the user why it is needed' },
53 },
54 required: ['name', 'reason'],
55 },
56 isDeferred: false,
57 })
58 await learnDotenv($, ['.env'])
59 return next(e)
60 })
61
62 // 2. The guard: .env may be read (its secrets come back hidden), never committed
63 on('tool.call', { tool: 'Bash' }, async ($, e, next) => {
64 const why = await commitBlockReason($, String(e.command || ''))
65 return why ? { deny: `secret-box: ${why} A pushed key can't be taken back.` } : next(e)
66 }).catch(() => ({ deny: 'secret-box: the .env guard failed, so this call is blocked to be safe.' }))
67
68 // 3. A call that reads a .env file: learn its secret values before it runs,
69 // so the redactor hides them in the output even when they look weak
70 // (a word password). Reading .env is fine; its secrets come back hidden.
71 on('tool.call', { tool: /^(Bash|Read|Grep|Edit|MultiEdit|NotebookEdit)$/ }, async ($, e, next) => {
72 const files = envFiles(e)
73 if (files.length > 0) await learnDotenv($, files)
74 return next(e)
75 }).catch(($, e, next) => (next.called ? next(e) : { deny: 'secret-box: could not check this .env file, so the call is blocked to be safe.' }))
76
77 // @.env would attach the raw file to your prompt
78 on('prompt.mention', { path: /(^|\/)\.env(\.[\w.-]+)?$/ }, async ($, e, next) =>
79 isEnvFile(e.path) ? { deny: 'secret-box: ask Claude to read .env instead; its secrets come back hidden' } : next(e))
80 .catch(() => ({ deny: 'secret-box: the .env guard failed' }))
81
82 // 4. The box. Claude calls the tool: open it, wait for you, save, answer.
83 on('tool.call', { tool: TOOL }, async ($, e, next) => {
84 const name = String(e.name || '').trim()
85 if (!/^[A-Za-z_][A-Za-z0-9_]*$/.test(name)) {
86 return { result: `"${name}" is not a valid variable name. Use letters, digits and underscores.` }
87 }
88 // A plain -p run has no one to type into the box
89 if ((await $.session.surfaces()).length === 0) {
90 return { result: `secret-box needs an interactive session to collect ${name}. Ask the user to run Claude Code interactively.` }
91 }
92 if (pending) return { result: `secret-box is already waiting for ${pending.name}. Ask for one secret at a time.` }
93
94 // `answer` stays undefined until Enter (the value) or Escape (empty)
95 pending = { name, reason: String(e.reason || ''), value: '', answer: undefined, isInBand: false }
96 const opened = await $.ui.open({ id: PANE, title: 'secret-box', focus: true, closeOnEscape: true, holdToasts: true, rows: 7 })
97 // A narrow terminal (under 144 columns) keeps the pane undrawn: use the band above the prompt instead
98 if (!opened.isPlaced) {
99 pending.isInBand = true
100 await $.ui.close({ id: PANE })
101 $.ui.invalidate('ui.render')
102 $.ui.toast(`Claude wants ${name}: press ctrl+x then tab to type it in the box above the prompt`, { timeoutMs: 10000 })
103 }
104
105 // A hook's own run time is capped at 10 s, but time inside a mods API call
106 // is not counted, so wait for the person in short `sleep` processes.
107 const deadline = (await $.clock.now()) + 10 * 60_000
108 while (pending.answer === undefined && !next.signal.aborted && (await $.clock.now()) < deadline) {
109 await $.process.run(['sleep', '0.3'])
110 }
111 const value = pending.answer
112 pending = null
113 await $.ui.close({ id: PANE })
114 $.ui.invalidate('ui.render')
115 if (!value) return { result: `The user cancelled. ${name} was not saved.` }
116
117 try {
118 const where = await saveToDotenv($, await $.session.cwd(), name, value)
119 const tag = keepSecret(value)
120 $.ui.toast(`${name} saved to ${where}`)
121 // The ONLY things Claude learns: the name, the place, and a placeholder
122 return { result: `The user entered ${name}. It was saved to ${where}. You can't see the value. To use it in a command or a file, write ${tag}: it becomes the real value when the tool runs and is hidden again in the output. Code should read it from the environment.` }
123 } catch (err) {
124 return { result: `Saving ${name} failed: ${String(err && err.message || err).slice(0, 300)}` }
125 }
126 }).catch(($, e, next) => {
127 // If the hook itself fails (or times out), drop the request and tell Claude plainly
128 pending = null
129 $.ui.log('request_secret failed: ' + JSON.stringify(next.error).slice(0, 500))
130 return { result: 'secret-box failed before anything was saved. Nothing was written.' }
131 })
132
133 // Draw the box, in our pane or (narrow terminal) in the band above the prompt
134 on('ui.render', { component: 'Pane' }, async ($, e, next) => {
135 if (e.requestId !== PANE || !pending) return next(e)
136 return drawBox($, e, pending)
137 })
138 on('ui.render', { component: 'AbovePrompt' }, async ($, e, next) => {
139 if (!pending || !pending.isInBand) return next(e)
140 return drawBox($, e, pending)
141 })
142
143 // Escape (or any close) on the pane before Enter means cancel
144 on('ui.close', async ($, e, next) => {
145 if (e.id === PANE && pending && !pending.isInBand) pending.answer = ''
146 return next(e)
147 }).catch(($, e, next) => next(e))
148}
149
150// .env, .env.local, .env.production ... but not .env.example and friends
151function isEnvFile(path) {
152 const base = String(path || '').split('/').pop()
153 return /^\.env(\.[\w.-]+)?$/.test(base) && !/\.(example|sample|template|dist)$/.test(base)
154}
155
156// The .env files a tool call reads or names, as written in the call
157function envFiles(e) {
158 const direct = [e.file_path, e.notebook_path, e.path].filter(isEnvFile)
159 const named = String(e.command || '').match(/(?:^|[^\w.\/-])((?:[\w.\/-]*\/)?\.env(?:\.[\w.-]+)?)(?![\w.-])/g) || []
160 return [...direct, ...named.map(m => m.replace(/^[^\w.\/-]/, '')).filter(isEnvFile)]
161}
162
163// Read .env files and hand every secret-named value to the vault, so it is
164// hidden wherever it turns up. Never throws: a file it can't read teaches it
165// nothing, and the redactor still scans the output.
166async function learnDotenv($, files) {
167 let cwd = ''
168 try { cwd = await $.session.cwd() } catch {}
169 for (const f of files) {
170 try {
171 const path = f.startsWith('/') ? f : f.startsWith('~/') ? f : cwd + '/' + f
172 if (path.startsWith('~/') || !(await $.fs.exists(path))) continue
173 for (const m of (await $.fs.read(path)).matchAll(ASSIGNMENT)) {
174 const value = m[3].trim().replace(/^["']|["']$/g, '')
175 if (value.length >= 6 && SECRET_NAME.test(m[2])) keepSecret(value)
176 }
177 } catch {}
178 }
179}
180
181// The repositories a command's git calls run in: each `git -C <dir>`, and the
182// session's own repository for a plain `git`
183function gitDirs(cmd) {
184 const dirs = new Set()
185 for (const m of cmd.matchAll(/\bgit((?:[ \t]+-c[ \t]+\S+|[ \t]+-C[ \t]+(?:"[^"]*"|'[^']*'|\S+))*)/g)) {
186 const c = m[1].match(/-C[ \t]+("[^"]*"|'[^']*'|\S+)/g)
187 if (!c) dirs.add('')
188 else dirs.add(c.at(-1).replace(/^-C[ \t]+/, '').replace(/^["']|["']$/g, ''))
189 }
190 return [...dirs]
191}
192
193// Why a Bash command must be blocked: it stages or commits a .env file
194async function commitBlockReason($, cmd) {
195 if (/\bgit\b[^;&|]*\badd\b/.test(cmd) && /\.env\b(?!\.(example|sample|template|dist))/.test(cmd)) {
196 return 'staging a .env file is blocked.'
197 }
198 if (!/\bgit\b[^;&|]*\bcommit\b/.test(cmd)) return ''
199 // The index is read before the command runs. If the same command stages
200 // (git add ... && git commit, or commit -a), count what it could stage too:
201 // every changed or untracked file git does not ignore.
202 const stages = /\bgit\b[^;&|]*\b(add|stage)\b/.test(cmd) || /\bcommit\b[^;&|]*\s(-a|--all|-\w*a\w*)\b/.test(cmd)
203 for (const dir of gitDirs(cmd)) {
204 const git = (...args) => $.process.run(['git', ...(dir ? ['-C', dir] : []), ...args])
205 const checks = [git('diff', '--cached', '--name-only')]
206 if (stages) checks.push(git('ls-files', '--modified', '--others', '--exclude-standard'))
207 for (const r of await Promise.all(checks)) {
208 if (r.exitCode !== 0) return `could not check what this commit includes${dir ? ' in ' + dir : ''}, so it is blocked.`
209 const env = r.stdout.split('\n').find(isEnvFile)
210 if (env) {
211 return stages
212 ? `this command could stage and commit ${env}. Add it to .gitignore, or stage named files in a separate step.`
213 : 'this commit would include a .env file. Unstage it with git rm --cached.'
214 }
215 }
216 }
217 return ''
218}
219
220// The field shows dots; the real text is kept in `p.value`, never drawn.
221function drawBox($, e, p) {
222 const { Box, Text, Input } = $.ui.resolve(e)
223 return (
224 <Box flexDirection="column" paddingX={1}>
225 <Text bold>Claude is asking for <Text color="yellow">{p.name}</Text></Text>
226 {p.reason ? <Text dimColor>{p.reason}</Text> : null}
227 <Input
228 key="secret"
229 label="value "
230 placeholder="paste it here, it stays masked"
231 value={DOT.repeat(p.value.length)}
232 submitLabel="save"
233 autoFocus
234 onInput={text => {
235 // Everything up to the first non-dot is the part we already hold;
236 // the rest is what was just typed or pasted. Backspace shortens the dots.
237 let kept = 0
238 while (kept < text.length && text[kept] === DOT) kept++
239 p.value = p.value.slice(0, Math.min(kept, p.value.length)) + text.slice(kept)
240 $.ui.invalidate('ui.render')
241 }}
242 onSubmit={() => { p.answer = p.value }}
243 />
244 <Text dimColor>{p.value.length ? `${p.value.length} characters · ` : ''}Enter saves · {p.isInBand ? 'ctrl+x tab to focus, Enter on empty cancels' : 'Esc cancels'} · Claude never sees the value</Text>
245 </Box>
246 )
247}
248
249async function saveToDotenv($, cwd, name, value) {
250 const path = cwd + '/.env'
251 const old = (await $.fs.exists(path)) ? await $.fs.read(path) : ''
252 const line = `${name}=${quote(value)}`
253 const lines = old.split('\n').filter((l, i, all) => !(i === all.length - 1 && l === ''))
254 const at = lines.findIndex(l => l.startsWith(name + '='))
255 if (at >= 0) lines[at] = line
256 else lines.push(line)
257 await $.fs.write(path, lines.join('\n') + '\n')
258
259 const gi = cwd + '/.gitignore'
260 const ignore = (await $.fs.exists(gi)) ? await $.fs.read(gi) : ''
261 const isIgnored = ignore.split('\n').some(l => ['.env', '.env*', '*.env', '/.env'].includes(l.trim()))
262 if (!isIgnored) await $.fs.write(gi, ignore + (ignore && !ignore.endsWith('\n') ? '\n' : '') + '.env\n')
263 return '.env' + (isIgnored ? '' : ' (and added .env to .gitignore)')
264}
265
266// Plain values stay bare; anything with spaces, quotes or # gets double quotes.
267function quote(v) {
268 return /^[A-Za-z0-9_\-.\/:+=@]*$/.test(v) ? v : '"' + v.replace(/\\/g, '\\\\').replace(/"/g, '\\"').replace(/\n/g, '\\n') + '"'
269}
270hooks/redact.ts 252 lines1import type { Register, PromptContextBlock } from 'claude-code'
2import {
3 makeConfig,
4 scrubSecrets,
5 scrubPii,
6 restore,
7 mint,
8 walk,
9 collect,
10 escapeLiteralTags,
11 type WalkState,
12} from './detect.ts'
13
14// transcript-redactor: keeps secrets (and, if asked, email addresses) out of
15// the session transcript. Everything that decides what a secret is lives in
16// ./detect.ts; this file only wires it to the events where text enters the
17// conversation, and to the tools where a placeholder must become real again.
18//
19// Every hook fails closed. A hook that throws or runs past its budget is
20// skipped by the engine, and for a redactor that would mean the raw text goes
21// through. So each one has a `.catch` that withholds instead.
22
23// The scan is linear, but a string past this size could still run past the
24// hook's 10 s budget. It is withheld rather than passed on unscanned.
25const SCAN_CAP = 16_000_000
26
27const WITHHELD =
28 'transcript-redactor could not scan this result in time, so it was withheld. Narrow the output (head, grep, offset) and retry.'
29const BLOCK_WITHHELD = '[transcript-redactor withheld this text: the scan failed]'
30
31// Tools whose answer carries live placeholders, so they are not turned into
32// quoted (LITERAL) ones: the subagent tools, whose answer holds placeholders
33// the subagent used. A mod built on this one can add its own tool here.
34export const LIVE_TAG_TOOLS = new Set(['Agent', 'Task'])
35
36// The name on the toast and the tool row. A mod built on this one sets its own.
37export const brand = { name: 'transcript-redactor' }
38
39// Attachments that carry text from outside the engine's own prose: a file,
40// a diff of a file, a queued prompt. These get the full scrub, emails too.
41const OUTSIDE_TEXT = new Set(['file', 'edited_text_file', 'queued_command'])
42
43type Budget = { budget: { remainingMs: number } }
44
45// Throws before a scan that cannot finish: the `.catch` then withholds.
46function guard(text: string, next: Budget): void {
47 if (text.length > SCAN_CAP) throw new Error('transcript-redactor: text too large to scan')
48 const needMs = 300 + text.length / 4000
49 if (next.budget.remainingMs < needMs) throw new Error('transcript-redactor: out of time')
50}
51
52// A Bash command that writes text into git history or posts it to GitHub.
53// Its placeholders stay placeholders: a commit message or an issue body that
54// quotes one must not carry the real key off the machine. The whole command
55// is left as written, so a step that needs the key goes in its own call.
56const PUBLISHES =
57 /\bgit\b(?:[ \t]+-[cC][ \t]+\S+|[ \t]+--?[\w-]+(?:=\S+)?)*[ \t]+(?:commit|tag|notes|send-email)\b|\bgh[ \t]+(?:issue|pr|release|gist|discussion|api|repo[ \t]+(?:create|edit))\b/
58
59// A restored value goes into Bash as shell source. One holding any of these
60// (quotes, $, backticks, separators, globs) could run as code there, so it is
61// never put into a command. Most keys are letters, digits and -_.+/=:
62const SHELL_ACTIVE = /[\s$`"'\\;&|<>()*?[\]{}#~]|[\x00-\x1f\x7f]/
63
64// @-mentioned files the engine attaches as media or a page reference, never
65// as text. When one is too large for $.fs.read it holds no text to check.
66const MEDIA_FILE = /\.(?:png|jpe?g|gif|webp|bmp|tiff?|heic|pdf)$/i
67
68function looksBinary(text: string): boolean {
69 const head = text.slice(0, 8192)
70 return head.includes('\u0000') || (head.match(/�/g)?.length ?? 0) > 8
71}
72
73export const register: Register = (on, options) => {
74 const cfg = makeConfig(options as Record<string, unknown>)
75
76 const scrub = (text: string): string => {
77 let out = text
78 if (cfg.secrets) out = scrubSecrets(out, cfg)
79 if (cfg.pii) out = scrubPii(out, cfg)
80 return out
81 }
82 const secretsOnly = (text: string): string => (cfg.secrets ? scrubSecrets(text, cfg) : text)
83
84 // Counts the values hidden, not the placeholders that stand for quoted text.
85 const countHidden = (tags: Set<string>): number => [...tags].filter((t) => !t.startsWith('[REDACTED-LITERAL-')).length
86
87 // 1. What the user types. A pasted key never reaches the model as itself,
88 // and neither does the context a hook above attached to the prompt.
89 on('prompt.submit', async ($, e, next) => {
90 const { value, tags } = collect(() => {
91 guard(e.text, next)
92 return { text: scrub(e.text), context: e.context?.map((c) => (guard(c, next), scrub(c))) }
93 })
94 const n = countHidden(tags)
95 if (n > 0 && cfg.notify) $.ui.toast(`${brand.name}: hid ${n} value(s) from the prompt`)
96 if (tags.size === 0) return next(e)
97 return next({ ...e, text: value.text, ...(value.context ? { context: value.context } : {}) })
98 }).catch(($, e, next) => (next.called ? next(e) : { drop: 'transcript-redactor failed to scan this prompt, so it was not sent.' }))
99
100 // 2. Every tool call. On the way in, a placeholder becomes its real value,
101 // but only for a tool that runs on this machine. On the way out, the
102 // result, the text the model reads and any attached context are scanned.
103 on('tool.call', async ($, e, next) => {
104 const command = (e as { command?: unknown }).command
105 const publishes = e.tool === 'Bash' && typeof command === 'string' && PUBLISHES.test(command)
106 const isLocal = cfg.restore && cfg.restoreTools.has(e.tool) && !publishes
107 // The real values this call was handed. Whatever the tool prints of them
108 // comes back hidden, even bare and short, where no detector would fire.
109 const handed = new Set<string>()
110 const restoreTracked = (s: string): string =>
111 restore(s) === s
112 ? s
113 : s.replace(/\[REDACTED-SECRET-[0-9a-f]{8}\]/g, (t) => {
114 const v = restore(t)
115 if (v !== t) handed.add(v)
116 return v
117 })
118 const rehideHanded = (text: string): string => {
119 let out = text
120 for (const v of [...handed].sort((a, b) => b.length - a.length)) if (v.length >= 4 && out.includes(v)) out = out.split(v).join(mint('SECRET', v))
121 return out
122 }
123 const input = isLocal ? (walk({ ...e }, restoreTracked) as typeof e) : e
124 if (e.tool === 'Bash' && [...handed].some((v) => SHELL_ACTIVE.test(v))) {
125 return {
126 deny: `${brand.name}: a secret in this command holds shell characters, so its real value was not put into Bash, where it could run as code. Write it to a file with the Write tool and have the command read that file instead.`,
127 }
128 }
129 const r = await next(input)
130 if (r.deny !== undefined) {
131 // A refusal from beneath may quote the input it refused, real values
132 // and all, and the model reads it as the tool's answer.
133 const d = collect(() => (guard(r.deny, next), rehideHanded(scrub(escapeLiteralTags(r.deny)))))
134 return d.tags.size === 0 ? r : { deny: d.value }
135 }
136
137 const escape = !LIVE_TAG_TOOLS.has(e.tool)
138 const st: WalkState = { incomplete: false }
139 // The result and the text often hold the same string: scan it once.
140 const memo = new Map<string, string>()
141 const clean = (s: string): string => {
142 const done = memo.get(s)
143 if (done !== undefined) return done
144 guard(s, next)
145 const out = rehideHanded(scrub(escape ? escapeLiteralTags(s) : s))
146 memo.set(s, out)
147 return out
148 }
149 const { value, tags } = collect(() => ({
150 result: walk(r.result, clean, st),
151 text: r.text === undefined ? undefined : clean(r.text),
152 context: r.context?.map(clean),
153 }))
154 if (tags.size === 0) return r
155 // Something was hidden, and part of the result could not be rewritten:
156 // that part may hold the same secret, so the whole result is withheld.
157 if (st.incomplete) return { deny: 'transcript-redactor: a secret sits in a part of this result it cannot rewrite (too deep, or not plain data). Narrow the call and retry.' }
158
159 const n = countHidden(tags)
160 if (cfg.notify && n > 0) $.ui.notice(e.tool_use_id, `${brand.name}: hid ${n} value(s)`)
161 const context = value.context ? { context: value.context } : {}
162 if (r.isError) return { isError: true as const, result: value.result, text: value.text, ...context }
163 return { result: value.result, ...context } as typeof r
164 }).catch(async ($, e, next) => {
165 // Nothing ran yet: refuse the call. The tool answered: withhold it.
166 if (!next.called) return { deny: WITHHELD }
167 const r = await next(e)
168 if (r.deny !== undefined) return { deny: WITHHELD }
169 if (r.isError) return { isError: true as const, result: WITHHELD, text: WITHHELD }
170 return { deny: WITHHELD }
171 })
172
173 // 3. The blocks attached to the first message (CLAUDE.md and friends).
174 // Secrets only: the email in there is the user's own, and the engine
175 // puts it there so the model knows who it is talking to.
176 on('prompt.context', async ($, e, next) => {
177 const r = await next(e)
178 if (!cfg.secrets) return r
179 const blocks: PromptContextBlock[] = r.blocks.map((b) => {
180 guard(b.text, next)
181 return { ...b, text: secretsOnly(b.text) }
182 })
183 // The raw files behind a rewritten CLAUDE.md would carry the key on to
184 // the hooks above, so they are left out once any block changed.
185 if (blocks.every((b, i) => b.text === r.blocks[i].text)) return r
186 return { blocks }
187 }).catch(async ($, e, next) => {
188 // Keep the blocks, so the model sees that something was held back.
189 const r = await next(e)
190 return { blocks: r.blocks.map((b) => ({ ...b, text: BLOCK_WITHHELD })) }
191 })
192
193 // 4. What the engine injects on its own after the first message: a file
194 // named with @, a diff of a file that changed on disk, a nested
195 // CLAUDE.md, a settings hook's context. None of it passes tool.call.
196 on('prompt.attachment', async ($, e, next) => {
197 const r = await next(e)
198 if (r.text == null) return r
199 const text = r.text
200 guard(text, next)
201 const isOutside = e.origin.kind !== 'engine' || OUTSIDE_TEXT.has(e.type)
202 const isFile = e.type === 'file' || e.type === 'edited_text_file'
203 const out = isOutside ? scrub(isFile ? escapeLiteralTags(text) : text) : secretsOnly(text)
204 return out === text ? r : { text: out }
205 }).catch(() => ({ text: BLOCK_WITHHELD }))
206
207 // 5. A file named with @ is read with no tool call, and its raw text is
208 // stored in the transcript whatever the model is shown. So a file that
209 // holds a secret is refused here, before it is read, and the model is
210 // told to use the Read tool, whose result is scrubbed.
211 on('prompt.mention', async ($, e, next) => {
212 if (!cfg.secrets) return next(e)
213 let text: string
214 try {
215 const read = await $.fs.read(e.path)
216 if (typeof read !== 'string') return next(e)
217 text = read
218 } catch {
219 // Missing: the engine attaches nothing. An image or a PDF too large to
220 // read is attached as media, not text. A text file that is present
221 // but unreadable (too large, say) cannot be checked, so it is refused.
222 if (!(await $.fs.exists(e.path))) return next(e)
223 if (MEDIA_FILE.test(e.path)) return next(e)
224 return { deny: 'transcript-redactor: could not check this file for secrets; ask Claude to Read it instead' }
225 }
226 if (looksBinary(text)) return next(e)
227 guard(text, next)
228 const { tags } = collect(() => scrubSecrets(text, cfg))
229 if (tags.size > 0) return { deny: 'transcript-redactor: this file holds a secret; ask Claude to Read it instead, so the value is replaced by a placeholder' }
230 return next(e)
231 }).catch(($, e, next) => (next.called ? next(e) : { deny: 'transcript-redactor: could not check this file for secrets' }))
232
233 // 6. A subagent's task. The model only ever holds placeholders, and the
234 // Agent tool gets no restore, so this is a second layer: a value that
235 // slipped into the prompt some other way still reaches the subagent as
236 // a placeholder. A workflow agent's prompt cannot be rewritten, only
237 // refused, so one that holds a secret is not started.
238 on('agent.spawn', async ($, e, next) => {
239 if (!cfg.secrets) return next(e)
240 if (e.workflow) {
241 guard(e.prompt, next)
242 const { tags } = collect(() => secretsOnly(e.prompt))
243 if (tags.size === 0) return next(e)
244 return { deny: "transcript-redactor: this workflow agent's prompt holds a secret, and a workflow prompt cannot be rewritten. Pass the value by a file or an env var instead." }
245 }
246 guard(e.prompt, next)
247 const prompt = secretsOnly(e.prompt)
248 const description = secretsOnly(e.description)
249 return prompt === e.prompt && description === e.description ? next(e) : next({ ...e, prompt, description })
250 }).catch(($, e, next) => (next.called ? next(e) : { deny: 'transcript-redactor failed to scan this task, so the subagent was not started.' }))
251}
252hooks/detect.ts 1600 lines1// The pure half of transcript-redactor: the config, the vault, the detectors,
2// and the walkers. Nothing in here touches `$` or registers a hook, so another
3// mod can vendor this file as it is and the tests can run it under plain node.
4//
5// The value is not deleted. It is put in a vault that lives in this module,
6// in memory, for the session, and the transcript gets a placeholder in its
7// place: `[REDACTED-SECRET-1a2b3c4d]`. Within one session the same value always
8// mints the same placeholder, so the model can still tell one customer from
9// another, and the placeholder is swapped back for the real value on the way
10// into a tool that runs on this machine, so a `Bash` command or a `Write` still
11// carries the real key.
12//
13// Nothing is written to disk. The vault dies with the session.
14
15export type Kind = 'SECRET' | 'EMAIL' | 'IP' | 'LITERAL'
16
17export type Config = {
18 secrets: boolean
19 pii: boolean
20 emails: boolean
21 privateIps: boolean
22 restore: boolean
23 restoreTools: ReadonlySet<string>
24 notify: boolean
25 minEntropy: number
26 minLength: number
27 contextMinEntropy: number
28 allow: ReadonlySet<string>
29 allowEmails: readonly string[]
30 allowPrefix: readonly string[]
31 denyPrefix: readonly string[]
32}
33
34// The tools that run on this machine. A placeholder is only swapped back for
35// its real value in these: a tool that hands its input to another model or to
36// the network (Agent, WebFetch, WebSearch, SendMessage, an MCP tool) gets the
37// placeholder as written.
38export const DEFAULT_RESTORE_TOOLS = 'Bash,Write,Edit,MultiEdit,NotebookEdit'
39
40// ---------------------------------------------------------------- the vault
41
42const byValue = new Map<string, string>()
43const byTag = new Map<string, string>()
44let hidden = 0
45let minted: Set<string> | null = null
46
47const TAG = /\[REDACTED-(?:SECRET|EMAIL|IP|LITERAL)-[0-9a-f]{8}\]/g
48const WHOLE_TAG = /^\[REDACTED-(?:SECRET|EMAIL|IP|LITERAL)-[0-9a-f]{8}\]$/
49
50function randomHex8(): string {
51 const bytes = new Uint8Array(4)
52 const crypto = (globalThis as { crypto?: { getRandomValues?: (values: Uint8Array) => Uint8Array } }).crypto
53 if (crypto?.getRandomValues) crypto.getRandomValues(bytes)
54 else for (let index = 0; index < bytes.length; index++) bytes[index] = Math.floor(Math.random() * 256)
55 return Array.from(bytes, byte => byte.toString(16).padStart(2, '0')).join('')
56}
57
58// Swaps a value for its placeholder and remembers both. A value that already
59// holds a placeholder from an earlier pass (a key inside a URL password) is
60// stored with that placeholder put back, so one restore gives the real text.
61export function mint(kind: Kind, raw: string): string {
62 hidden++
63 const value = kind === 'LITERAL' ? raw : restore(unpark(raw))
64 const seen = byValue.get(value)
65 if (seen) {
66 if (kind === 'SECRET') remember(value)
67 minted?.add(seen)
68 return seen
69 }
70 let tag: string
71 do tag = `[REDACTED-${kind}-${randomHex8()}]`
72 while (byTag.has(tag))
73 byValue.set(value, tag)
74 byTag.set(tag, value)
75 if (kind === 'SECRET') remember(value)
76 minted?.add(tag)
77 return tag
78}
79
80// A secret is hidden again wherever it turns up later: across the session
81// when it is distinctive enough (echoable), and within the text being
82// scanned right now when it is shorter but still not a plain word.
83function remember(value: string): void {
84 const echoes = echoable(value)
85 if (echoes && !echo.has(value)) {
86 echo.add(value)
87 echoIndex = null
88 }
89 if (local && (echoes || localWorthy(value))) local.add(value)
90}
91
92// One pass, on purpose: a LITERAL placeholder gives back the placeholder text
93// it stands for, and that text must not then turn into the secret.
94export function restore(text: string): string {
95 if (byTag.size === 0 || !text.includes('[REDACTED-')) return text
96 return text.replace(TAG, (tag) => byTag.get(tag) ?? tag)
97}
98
99// Hides a value the caller knows is secret wherever it turns up for the rest
100// of the session, even one too short or too plain for the echo rule (a word
101// password from .env). Values under PREFIX characters can't be indexed.
102export function keepSecret(value: string): string {
103 const tag = mint('SECRET', value)
104 if (value.length >= PREFIX && !echo.has(value)) {
105 echo.add(value)
106 echoIndex = null
107 }
108 return tag
109}
110
111// How many times a value has been hidden this session. A hook reads it before
112// and after a scrub to learn whether anything changed.
113export function hiddenCount(): number {
114 return hidden
115}
116
117// Runs `fn` and hands back every placeholder it minted or reused, so a hook
118// can count the values it hid without counting one value twice.
119export function collect<T>(fn: () => T): { value: T; tags: Set<string> } {
120 const outer = minted
121 const tags = new Set<string>()
122 minted = tags
123 try {
124 return { value: fn(), tags }
125 } finally {
126 minted = outer
127 if (outer) for (const t of tags) outer.add(t)
128 }
129}
130
131// A placeholder read back from a file or a log is quoted text, not a handle.
132// Left alone it would turn into the real secret the next time the model
133// copied that text into a command. So a live placeholder found in a tool's
134// output is swapped for a LITERAL one, which restores to the placeholder text
135// and nothing more. Run this before the detectors, so a key the tool printed
136// still comes back as its live placeholder.
137export function escapeLiteralTags(text: string): string {
138 if (byTag.size === 0 || !text.includes('[REDACTED-')) return text
139 return text.replace(TAG, (t) => (byTag.has(t) && !t.startsWith('[REDACTED-LITERAL-') ? mint('LITERAL', t) : t))
140}
141
142// ------------------------------------------------------- known value echoes
143
144// A value hidden once because of where it sat (after `API_KEY=`, inside a
145// URL) is hidden again wherever it turns up, even bare, where no detector
146// would fire on it: a tool that echoes a restored key must not print it.
147const echo = new Set<string>()
148let echoIndex: EchoIndex | null = null
149// The values minted during the current scan, to hide at their other spots.
150let local: Set<string> | null = null
151
152// Short or all-letter values (`postgres`) are left out: hiding every later
153// `postgres` in unrelated output would make the session unreadable.
154function echoable(value: string): boolean {
155 if (countsUp(value)) return false
156 // A slug or a dated name hidden once beside a key name is not worth hiding
157 // everywhere: it would turn every path that holds it into a placeholder.
158 if (value.split(/[^A-Za-z0-9]+/).every((p) => p === '' || isSlugPart(p))) return false
159 if (value.includes('\n')) return value.length >= 40
160 return value.length >= 20 || (value.length >= 10 && /[0-9]/.test(value) && /[A-Za-z]/.test(value))
161}
162
163// A value too short to hide across the session is still hidden at its other
164// spots in the same text, unless it is a plain word or slug (`postgres`
165// hidden once in a URL must not turn every `postgres://` into a placeholder).
166function localWorthy(value: string): boolean {
167 if (value.length < PREFIX || value.length > 400 || value.includes('\n') || countsUp(value)) return false
168 if (value.split(/[^A-Za-z0-9]+/).every((p) => p === '' || isSlugPart(p))) return false
169 return /[0-9]/.test(value) || /[^A-Za-z0-9]/.test(value) || value.length >= 12
170}
171
172// The known values are found with a rolling hash over their first PREFIX
173// characters, so the cost of the scan does not grow with the vault. A regex
174// of every value joined by `|` took 40 s on 200 KB once a long session had
175// hidden a few thousand values.
176const PREFIX = 8
177// Under each prefix the values are kept by length, longest first, so a
178// prefix that thousands of values share costs one set lookup per length,
179// not a walk of the whole list.
180type ByLength = { lengths: number[]; values: Set<string> }
181type EchoIndex = { hashes: Set<number>; byPrefix: Map<string, ByLength>; top: number }
182
183function prefixHash(text: string, at: number): number {
184 let h = 0
185 for (let i = 0; i < PREFIX; i++) h = (Math.imul(h, 31) + text.charCodeAt(at + i)) >>> 0
186 return h
187}
188
189function buildEchoIndex(values: Iterable<string>): EchoIndex {
190 const byPrefix = new Map<string, ByLength>()
191 for (const v of values) {
192 const p = v.slice(0, PREFIX)
193 let entry = byPrefix.get(p)
194 if (!entry) byPrefix.set(p, (entry = { lengths: [], values: new Set() }))
195 if (!entry.lengths.includes(v.length)) entry.lengths.push(v.length)
196 entry.values.add(v)
197 }
198 for (const entry of byPrefix.values()) entry.lengths.sort((a, b) => b - a)
199 const hashes = new Set<number>()
200 for (const p of byPrefix.keys()) hashes.add(prefixHash(p, 0))
201 // 31 to the power PREFIX - 1, to take the oldest character out of the hash.
202 let top = 1
203 for (let i = 0; i < PREFIX - 1; i++) top = Math.imul(top, 31) >>> 0
204 return { hashes, byPrefix, top }
205}
206
207function rehideKnown(text: string): string {
208 if (echo.size === 0 || text.length < PREFIX) return text
209 return rehideWith(text, (echoIndex ??= buildEchoIndex(echo)))
210}
211
212// The values minted in one scan, hidden at their other spots in it. A few
213// values are found faster one by one than by the rolling hash.
214function rehideLocal(text: string, values: Set<string>): string {
215 if (values.size > 64) return rehideWith(text, buildEchoIndex(values))
216 let out = text
217 for (const v of [...values].sort((a, b) => b.length - a.length)) if (out.includes(v)) out = out.split(v).join(mint('SECRET', v))
218 return out
219}
220
221function rehideWith(text: string, ix: EchoIndex): string {
222 if (text.length < PREFIX) return text
223 const parts: string[] = []
224 let last = 0
225 let h = prefixHash(text, 0)
226 for (let i = 0; i + PREFIX <= text.length; ) {
227 if (ix.hashes.has(h)) {
228 const entry = ix.byPrefix.get(text.slice(i, i + PREFIX))
229 let found: string | undefined
230 if (entry) {
231 for (const n of entry.lengths) {
232 const v = text.slice(i, i + n)
233 if (v.length === n && entry.values.has(v)) {
234 found = v
235 break
236 }
237 }
238 }
239 if (found) {
240 parts.push(text.slice(last, i), mint('SECRET', found))
241 i += found.length
242 last = i
243 if (i + PREFIX <= text.length) h = prefixHash(text, i)
244 continue
245 }
246 }
247 if (i + PREFIX >= text.length) break
248 h = (Math.imul((h - Math.imul(text.charCodeAt(i), ix.top)) >>> 0, 31) + text.charCodeAt(i + PREFIX)) >>> 0
249 i++
250 }
251 if (last === 0) return text
252 parts.push(text.slice(last))
253 return parts.join('')
254}
255
256// ------------------------------------------------------------------ parking
257
258// Some spans are known not to be secrets and are big enough to drown the
259// transcript in placeholders: an image in a data: URI, a lockfile hash, a
260// thinking-block signature, a base64 attachment. They are parked behind a
261// marker for the scan and put back after it. The marker is a character the
262// text does not contain; if every candidate is taken, nothing is parked and
263// the scan simply hides more.
264type Parked = { mark: string; spans: string[]; re: RegExp }
265let parked: Parked | null = null
266const MARKS = ['\u0000', '\uE000', '\uE001', '\uFDD0']
267
268function startParking(text: string): Parked | null {
269 const mark = MARKS.find((m) => !text.includes(m))
270 return mark ? { mark, spans: [], re: new RegExp(`${mark}(\\d+)${mark}`, 'g') } : null
271}
272
273function park(span: string): string {
274 if (!parked) return span
275 parked.spans.push(span)
276 return `${parked.mark}${parked.spans.length - 1}${parked.mark}`
277}
278
279function unpark(text: string): string {
280 const p = parked
281 if (!p || !text.includes(p.mark)) return text
282 let out = text
283 for (let i = 0; i < 3 && out.includes(p.mark); i++) out = out.replace(p.re, (_m, n: string) => p.spans[Number(n)] ?? '')
284 return out
285}
286
287// ------------------------------------------------------------- small tools
288
289// Bits per character. Counted in a reused array for plain ASCII, since the
290// scan calls this for every candidate token.
291const COUNTS = new Int32Array(128)
292
293function entropy(text: string): number {
294 let ascii = true
295 for (let i = 0; i < text.length; i++) {
296 const c = text.charCodeAt(i)
297 if (c >= 128) {
298 ascii = false
299 break
300 }
301 }
302 if (!ascii) {
303 const counts = new Map<string, number>()
304 for (const ch of text) counts.set(ch, (counts.get(ch) ?? 0) + 1)
305 let h = 0
306 for (const n of counts.values()) h -= (n / text.length) * Math.log2(n / text.length)
307 return h
308 }
309 COUNTS.fill(0)
310 for (let i = 0; i < text.length; i++) COUNTS[text.charCodeAt(i)]!++
311 let h = 0
312 for (let c = 0; c < 128; c++) {
313 const n = COUNTS[c]!
314 if (n > 0) h -= (n / text.length) * Math.log2(n / text.length)
315 }
316 return h
317}
318
319const B64_TABLE = (() => {
320 const t = new Int16Array(128).fill(-1)
321 const abc = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
322 for (let i = 0; i < abc.length; i++) t[abc.charCodeAt(i)] = i
323 t['-'.charCodeAt(0)] = 62
324 t['_'.charCodeAt(0)] = 63
325 return t
326})()
327
328// Decodes the start of a base64 text into one character per byte. The hooks
329// run with no Buffer and no atob, so this is done by hand.
330function decodeBase64Head(text: string, max = 8192): string {
331 let out = ''
332 let acc = 0
333 let bits = 0
334 for (let i = 0; i < text.length && out.length < max; i++) {
335 const c = text.charCodeAt(i)
336 if (c === 61) break
337 const v = c < 128 ? B64_TABLE[c]! : -1
338 if (v < 0) continue
339 acc = ((acc << 6) | v) & 0xffffff
340 bits += 6
341 if (bits >= 8) {
342 bits -= 8
343 out += String.fromCharCode((acc >> bits) & 0xff)
344 }
345 }
346 return out
347}
348
349// Ranges of the text that the token scan skips. A `soft` range is skipped
350// only when no key name stands in front of the token.
351type Span = [start: number, end: number, soft: boolean]
352
353class Spans {
354 private list: Span[] = []
355 private i = 0
356 add(start: number, end: number, soft = false): void {
357 if (end > start) this.list.push([start, end, soft])
358 }
359 seal(): this {
360 this.list.sort((a, b) => a[0] - b[0])
361 return this
362 }
363 // Offsets are asked in ascending order, so a cursor keeps this linear.
364 at(offset: number): 'hard' | 'soft' | null {
365 const l = this.list
366 while (this.i < l.length && l[this.i]![1] <= offset) this.i++
367 let found: 'hard' | 'soft' | null = null
368 for (let j = this.i; j < l.length && l[j]![0] <= offset; j++) {
369 if (l[j]![1] > offset) {
370 if (!l[j]![2]) return 'hard'
371 found = 'soft'
372 }
373 }
374 return found
375 }
376}
377
378// ------------------------------------------------------------ secret tests
379
380// Escapes that end in a letter or digit and may sit right before a key:
381// quoted-printable `=3D`, URL `%3D`, and the `\n` or `"` of escaped JSON.
382const ESC = String.raw`[%=]3D|\\[nrtfbv]|\\u[0-9A-Fa-f]{4}`
383const UUID = '[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}'
384
385// A vendor prefix only counts at the start of a word, or right after one of
386// those escapes. Without this, `task-runner-for-the-build` reads as `sk-`.
387// The prefix is written first and the boundary checked behind it, so the
388// regex engine can jump between occurrences of the prefix instead of
389// testing the boundary at every character of the text.
390function word(prefix: string, body: string, edge = 'A-Za-z0-9'): string {
391 return String.raw`${prefix}(?<=(?:^|[^${edge}]|${ESC})${prefix})${body}`
392}
393
394// Shapes that belong to one vendor and mean one thing. These are hidden on
395// sight, whatever their entropy. Each has a hint, a cheap test that the text
396// could hold one, so a 10 MB log pays only for the shapes it might contain.
397// Every quantifier is bounded: an open `{n,}` over a run of millions of
398// characters overflows the regex stack.
399type Shape = { hint: string | RegExp; re: string }
400const VENDOR_SHAPES: readonly Shape[] = [
401 { hint: 'sk-ant-', re: word('sk-ant-', '[A-Za-z0-9_-]{16,4096}') },
402 // A real OpenAI key has a digit or a capital early on; a kebab word does not.
403 { hint: 'sk-', re: word('sk-', '(?=[a-z_-]{0,200}[0-9A-Z])[A-Za-z0-9_-]{20,4096}') },
404 { hint: /gh[pousr]_/, re: word('gh[pousr]_', '[A-Za-z0-9]{20,4096}') },
405 { hint: 'github_pat_', re: word('github_pat_', '[A-Za-z0-9_]{20,4096}') },
406 { hint: 'xox', re: word('xox[baprse]-', '[A-Za-z0-9-]{10,4096}') },
407 { hint: 'xapp-', re: word('xapp-', '[0-9]-[A-Za-z0-9-]{10,4096}') },
408 { hint: /A[KS]IA/, re: word('A(?:KIA|SIA)', '[0-9A-Z]{16}(?![A-Za-z0-9])') },
409 { hint: /[sr]k_(?:live|test)_/, re: word('[sr]k_(?:live|test)_', '[A-Za-z0-9]{16,4096}') },
410 { hint: 'whsec_', re: word('whsec_', '[A-Za-z0-9]{16,4096}') },
411 { hint: 'AIza', re: word('AIza', '[0-9A-Za-z_-]{30,4096}') },
412 { hint: 'ya29.', re: word(String.raw`ya29\.`, '[A-Za-z0-9_-]{20,4096}') },
413 { hint: 'npm_', re: word('npm_', '[A-Za-z0-9]{30,4096}') },
414 { hint: 'dop_v1_', re: word('dop_v1_', '[a-f0-9]{40,4096}') },
415 { hint: 'glpat-', re: word('glpat-', '[A-Za-z0-9_-]{16,4096}') },
416 { hint: 'shpat_', re: word('shpat_', '[a-f0-9]{32,4096}') },
417 { hint: 'SG.', re: word(String.raw`SG\.`, String.raw`[A-Za-z0-9_-]{16,4096}\.[A-Za-z0-9_-]{16,4096}`) },
418 { hint: 'hooks.slack.com', re: String.raw`https://hooks\.slack\.com/services/[A-Za-z0-9/+_-]{16,4096}` },
419 { hint: '/api/webhooks/', re: String.raw`https://discord(?:app)?\.com/api/webhooks/[0-9]{1,30}/[A-Za-z0-9_-]{16,4096}` },
420 // Prefixes built from words, which the name test would otherwise excuse.
421 { hint: 'vercel_blob_rw_', re: word('vercel_blob_rw_', '[A-Za-z0-9]{16}_[A-Za-z0-9]{30}') },
422 { hint: 'tskey-', re: word('tskey-', '[a-z]{1,20}-[A-Za-z0-9_-]{20,4096}') },
423 { hint: 'pscale_', re: word('pscale_', '(?:tkn|pw|oauth)_[A-Za-z0-9_-]{32,4096}') },
424 { hint: 'pdl_', re: word('pdl_', '(?:live|sdbx)_apikey_[A-Za-z0-9_-]{20,4096}') },
425 { hint: 'pypi-AgE', re: word('pypi-AgE', '[A-Za-z0-9_-]{50,4096}') },
426 { hint: 'sntrys_eyJ', re: word('sntrys_eyJ', '[A-Za-z0-9+/=_-]{50,4096}') },
427 { hint: 'pcsk_', re: word('pcsk_', '[A-Za-z0-9_-]{40,4096}') },
428 { hint: 'HRKU-AA', re: word('HRKU-AA', '[A-Za-z0-9_-]{40,4096}') },
429 { hint: 'dckr_', re: word('dckr_', '(?:pat|oat)_[A-Za-z0-9_-]{20,4096}') },
430 { hint: 'figd_', re: word('figd_', '[A-Za-z0-9_-]{30,4096}') },
431 { hint: 'GOCSPX-', re: word('GOCSPX-', '[A-Za-z0-9_-]{20,4096}') },
432 { hint: /gl(?:rt|dt|ptt|cbt|imt|ft|soat|oas|agent)-/, re: word('gl(?:rt|dt|ptt|cbt|imt|ft|soat|oas|agent)-', '[A-Za-z0-9_-]{20,4096}') },
433 { hint: 'bb_live_', re: word('bb_live_', '[A-Za-z0-9_-]{20,4096}') },
434 { hint: 'sb_secret_', re: word('sb_secret_', '[A-Za-z0-9_-]{20,4096}') },
435 { hint: 'ATATT3', re: word('ATATT3', '[A-Za-z0-9_=-]{100,4096}') },
436 // Keys whose secret half sits after a `.`, `:` or `/`.
437 { hint: 'pat', re: word('pat', String.raw`[A-Za-z0-9]{14}\.[a-f0-9]{64}`) },
438 { hint: /[st]k\.eyJ/, re: word(String.raw`[st]k\.eyJ`, String.raw`[A-Za-z0-9_-]{10,4096}\.[A-Za-z0-9_-]{20,4096}`) },
439 { hint: 'st.', re: word(String.raw`st\.`, String.raw`(?:[0-9a-f]{24}|${UUID})\.[0-9a-f]{32}\.[0-9a-f]{32}`) },
440 { hint: /\/[0-9]{8}[0-9/]*:[0-9a-f]{32}/, re: String.raw`(?<![0-9])[0-9]/[0-9]{8,30}(?:/[0-9]{8,30})?:[0-9a-f]{32}` },
441 { hint: /-[0-9a-f]{12}:[0-9a-f]{32}/, re: String.raw`(?<![0-9A-Fa-f])${UUID}:[0-9a-f]{32}` },
442 // Hugging Face tokens are letters only, so no entropy rule can see them.
443 { hint: /(?:hf|api_org)_/, re: word('(?:hf|api_org)_', '[A-Za-z0-9]{34}(?![A-Za-z0-9_])') },
444 { hint: 'ops_eyJ', re: word('ops_eyJ', '[A-Za-z0-9+/=_-]{50,4096}') },
445 { hint: /fm[12][ar]?_/, re: word('fm[12][ar]?_', '[A-Za-z0-9+/=,_-]{50,4096}') },
446 { hint: 'sig=', re: String.raw`(?<=[?&]sig=)[A-Za-z0-9%+/]{30,4096}` },
447 { hint: 'AAAAAAAAAAAAAAAAAAAAA', re: word('AAAAAAAAAAAAAAAAAAAAA', '[A-Za-z0-9]{0,200}%[A-Za-z0-9%]{30,4096}') },
448 { hint: 'Q~', re: String.raw`[A-Za-z0-9_~.-]{3}[0-9][A-Za-z0-9_~.-]Q~[A-Za-z0-9_~.-]{31,34}` },
449 // Lowercase and hex shapes that one vendor owns.
450 { hint: 'e2b_', re: word('e2b_', String.raw`[a-f0-9]{40}(?![\w-])`) },
451 { hint: 'lsv2_', re: word('lsv2_', String.raw`(?:pt|sk)_[a-f0-9]{32}_[a-f0-9]{10}(?![\w-])`) },
452 { hint: /[0-9a-f]-us[0-9]/, re: String.raw`(?:(?<=${ESC})|(?<![A-Za-z0-9]))[a-f0-9]{32}-us[0-9]{1,2}(?![\w-])` },
453 { hint: /-[a-f0-9]{8}-[a-f0-9]{8}(?![\w-])/, re: String.raw`(?:(?<=${ESC})|(?<![A-Za-z0-9]))[a-f0-9]{32}-[a-f0-9]{8}-[a-f0-9]{8}(?![\w-])` },
454 { hint: /xa[ap]t-/, re: word('xa[ap]t-', String.raw`${UUID}(?![\w-])`) },
455 { hint: 'SK', re: word('SK', String.raw`[0-9a-f]{32}(?![\w-])`) },
456 { hint: 'tvly-', re: word('tvly-', '(?:dev-|prod-)?[A-Za-z0-9]{32,4096}') },
457 { hint: 'tr_', re: word('tr_', '(?:dev|prod|stg|pat)_[A-Za-z0-9]{20,4096}', 'A-Za-z0-9_') },
458 { hint: ':AA', re: String.raw`(?<![0-9])[0-9]{8,10}:AA[A-Za-z0-9_-]{33}(?![A-Za-z0-9_-])` },
459 { hint: /a[ks]-/, re: word('a[ks]-', '[A-Za-z0-9]{22}(?![A-Za-z0-9_-])', 'A-Za-z0-9_-') },
460 // Keys that reuse a Stripe id prefix: Resend `re_`, Stripe client secrets.
461 { hint: 're_', re: word('re_', '[A-Za-z0-9]{8}_[A-Za-z0-9]{24}(?![A-Za-z0-9_])', 'A-Za-z0-9_') },
462 { hint: '_secret_', re: word('(?:pi|seti)_', '[A-Za-z0-9]{14,64}_secret_[A-Za-z0-9]{16,4096}', 'A-Za-z0-9_') },
463 // A Klaviyo private key is `pk_` and 34 alnum. Stripe and Clerk publishable
464 // keys always carry `live_` or `test_` after `pk_`, so they do not match.
465 { hint: 'pk_', re: word('pk_', '[A-Za-z0-9]{34}(?![A-Za-z0-9_])', 'A-Za-z0-9_') },
466 // An age identity (SOPS reads it from keys.txt) is upper case and digits.
467 { hint: 'AGE-SECRET-KEY-1', re: word('AGE-SECRET-KEY-1', '[0-9A-Z]{58}') },
468 { hint: 'AGE-PLUGIN-', re: word('AGE-PLUGIN-[A-Z0-9]{1,40}-1', '[0-9A-Z]{20,4096}') },
469 // Tokens that are not mixed case, so no entropy rule sees them alone.
470 { hint: /NR(?:AK|II|JS|AA|RA)-/, re: word('NR(?:AK|II|JS|AA|RA)-', '[A-Za-z0-9_-]{27,40}') },
471 { hint: 'dt0c01.', re: word(String.raw`dt0c01\.`, String.raw`[A-Z0-9]{24}\.[A-Z0-9]{64}`) },
472 { hint: /pat-(?:na|eu|ap)[0-9]-/, re: word('pat-(?:na|eu|ap)[0-9]-', String.raw`${UUID}(?![\w-])`) },
473 { hint: /(?:sdk|api)-[0-9a-f]{8}-/, re: word('(?:sdk|api)-', String.raw`${UUID}(?![\w-])`) },
474 { hint: 'lin_oauth_', re: word('lin_oauth_', '[a-f0-9]{64}') },
475 { hint: 'shippo_', re: word('shippo_(?:live|test)_', '[a-f0-9]{40}') },
476 { hint: 'dapi', re: word('dapi', String.raw`[a-f0-9]{32}(?:-[0-9]{1,2})?(?![\w-])`) },
477 { hint: ':fx', re: String.raw`(?<![0-9a-f-])${UUID}:fx(?!\w)` },
478 { hint: 'access_token$', re: String.raw`access_token\$(?:production|sandbox)\$[a-z0-9]{16}\$[a-f0-9]{32}` },
479 // A Twilio auth token is plain hex; it is known by the account SID beside it.
480 { hint: /AC[0-9a-f]{32}["']?[ \t]*[,:]/, re: String.raw`(?<=\bAC[0-9a-f]{32}["']?[ \t]*[,:][ \t]*["']?)[0-9a-f]{32}(?![0-9A-Za-z])` },
481]
482
483// Each shape also takes in the rest of its token, so a match that stops at a
484// `-` or `_` inside a key cannot leave the tail of the key on screen.
485const VENDOR = VENDOR_SHAPES.map((s) => ({ hint: s.hint, re: new RegExp(`(?:${s.re})[A-Za-z0-9_-]{0,4096}`, 'g') }))
486
487function scrubVendors(text: string, cfg: Config): string {
488 let out = text
489 for (const { hint, re } of VENDOR) {
490 if (typeof hint === 'string' ? !out.includes(hint) : !hint.test(out)) continue
491 out = out.replace(re, (m) => (cfg.allow.has(m) || m.includes('[REDACTED-') ? m : mint('SECRET', m)))
492 }
493 return out
494}
495
496// A private key block, up to its END line (never past the next BEGIN, so a
497// file of BEGIN lines is not scanned again for each one). When the END line
498// is missing (`head key.pem`), the base64 lines that follow the BEGIN line
499// are still taken, and only those.
500const PRIVATE_KEY =
501 /-----BEGIN[^\n-]{0,40}PRIVATE KEY(?: BLOCK)?-----(?:(?:(?!-----BEGIN)[\s\S]){0,65536}?-----END[^\n-]{0,40}PRIVATE KEY(?: BLOCK)?-----|(?:\r?\n(?:[A-Za-z][A-Za-z-]{0,40}: [^\n]*|[ \t]*))*(?:\r?\n[A-Za-z0-9+/=]{4}[A-Za-z0-9+/=]*(?=\r?\n|$))+)/g
502const PUTTY_PRIVATE = /(Private-Lines: \d+\r?\n)((?:[A-Za-z0-9+/=]{1,80}(?:\r?\n|$))+)/g
503
504// A run of dot-separated parts, where a JWT may hide. It has one starting
505// point per run, so a long run is scanned once. A JWT regex of its own went
506// quadratic on base64 JSON, where every row starts with `eyJ`.
507const DOTTED = /(?<![A-Za-z0-9_-])[A-Za-z0-9_-]+(?:\.[A-Za-z0-9_-]+)(?:\.[A-Za-z0-9_-]+)+/g
508
509// The password inside a connection string: postgres://user:REDACTED@host.
510// The user may be empty (redis://:pw@host), and the password may hold `/` or
511// `@`: it ends at the `@` that is followed by a host.
512const URL_PASSWORD =
513 /\b([a-z][a-z0-9+.-]{1,20}:\/\/[^\s/@:[\]]{0,80}):(?!\d{1,5}(?:[/?#]|$))([^\s"'`<>]{3,200}?)@(?=[A-Za-z0-9.-]{1,253}(?::\d{1,5})?(?:[/?#\s"'`<>]|$))/gi
514
515// A token used alone as the userinfo: `https://<token>@dev.azure.com/...`,
516// the documented clone form for Azure DevOps, GitHub and Bitbucket tokens.
517const URL_USERINFO = /\b([a-z][a-z0-9+.-]{1,20}:\/\/)([A-Za-z0-9_-]{20,200})@(?=[A-Za-z0-9.-]{1,253}(?::\d{1,5})?[/:])/g
518
519// A credential in a URL query: ?api_key=, &sig=, ?accessToken=. The value may
520// be percent-encoded, so it is decoded before it is judged.
521const URL_KEYWORD =
522 '(?:[Aa]pi[_-]?[Kk]ey|API[_-]?KEY|[Aa]pikey|[Kk]ey|KEY|[Tt]oken|TOKEN|[Ss]ecret|SECRET|[Ss]ig|SIG|[Ss]ignature|SIGNATURE|[Pp]assword|PASSWORD|[Pp]asswd|[Pp]wd|PWD|[Aa]uth|AUTH|[Cc]redential|CREDENTIAL)'
523const URL_PARAM = new RegExp(
524 String.raw`([?&;](?:[A-Za-z0-9._-]*[_.-]|[a-z0-9]+(?=[A-Z]))?${URL_KEYWORD}=)((?:[A-Za-z0-9+_~-]|%[0-9A-Fa-f]{2}){8,400}={0,2})(?=[&#\s"'<>)\]]|$)`,
525 'g',
526)
527
528// Values after a password-like key, judged by the key and not by entropy:
529// a human password (`Summer2024!`, `hunter2hunter2`) has too little.
530const PW_WORD = String.raw`(?:password|passwd|passphrase|secret|secret[_-]?key|client[_-]?secret|api[_-]?key|apikey|private[_-]?key|secret[_-]?access[_-]?key|access[_-]?key|auth[_-]?token)`
531// Short password names (`pass`, `pw`, `pwd`, `passcode`). They count only as
532// the whole key or after a separator, so `compass` and `bypass` are left.
533const SHORT_PW = String.raw`(?:pass(?:[_-]?code)?|pwd?)`
534const SHORT_KEY = new RegExp(String.raw`(?:^|[_.-])${SHORT_PW}$`, 'i')
535// A short key (`pass:`) with a number or a short word after it is a count
536// or a status, not a password.
537const shortKeyStatus = (key: string, v: string): boolean => SHORT_KEY.test(key) && (/^[0-9]+$/.test(v) || /^[a-z]{1,8}$/.test(v))
538const STRONG_QUOTED = new RegExp(
539 String.raw`((?:^|[\s{,;(\[])(\\?["']?)((?:[A-Za-z0-9._-]*[_.-]|pg)?${PW_WORD}|(?:[A-Za-z0-9._-]*[_.-])?${SHORT_PW})\2[ \t]*[:=][ \t]*)(\\?["'])([^\n]{3,200}?)\4`,
540 'gim',
541)
542// A YAML list item (`- password: x`, compose `- DB_PASS=x`) counts too.
543const STRONG_LINE = new RegExp(
544 String.raw`^([ \t]*(?:-[ \t]+)?(?:export[ \t]+)?([A-Za-z0-9._-]*${PW_WORD}|(?:[A-Za-z0-9._-]*[_.-])?${SHORT_PW})[ \t]*[:=][ \t]*)([^\s"'#;][^\s"';]{2,199})[ \t]*$`,
545 'gim',
546)
547// `DB_PASS=`: upper case with a separator only, so prose `Pass:` is left.
548const ENV_PASS = /^([ \t]*(?:-[ \t]+)?(?:export[ \t]+)?()[A-Z0-9_]*_PASS[ \t]*[:=][ \t]*)([^\s"'#;][^\s"';]{2,199})[ \t]*$/gm
549// A Gmail app password written unquoted: four groups of four letters.
550const APP_PASSWORD = new RegExp(
551 String.raw`^([ \t]*(?:-[ \t]+)?(?:export[ \t]+)?[A-Za-z0-9._-]*${PW_WORD}[ \t]*[:=][ \t]*)([a-z]{4}(?: [a-z]{4}){3})[ \t]*$`,
552 'gim',
553)
554// The line after a YAML block indicator: `password: |` then the value.
555const BLOCK_PASSWORD = new RegExp(
556 String.raw`^([ \t]*(?:-[ \t]+)?["']?[A-Za-z0-9._-]*${PW_WORD}["']?[ \t]*:[ \t]*[|>][-+]?[0-9]?[ \t]*\r?\n[ \t]+)(\S[^\n]{2,199}?)[ \t]*(?=\r?$)`,
557 'gim',
558)
559// SQL: `CREATE USER x WITH PASSWORD '...'`, MySQL `IDENTIFIED BY '...'`.
560const SQL_PASSWORD =
561 /(\b(?:(?:with|encrypted|unencrypted)[ \t]+password|identified[ \t]+(?:with[ \t]+\S+[ \t]+)?by(?:[ \t]+password)?)[ \t]+)'([^'\n]{3,200})'/gi
562// Terraform: the default of a variable whose name says it is a password.
563const HCL_DEFAULT = new RegExp(String.raw`(\bvariable[ \t]+"[\w-]*${PW_WORD}"[ \t]*\{[^{}]{0,400}?\bdefault[ \t]*=[ \t]*")([^"\n]{3,200})"`, 'gi')
564// Terraform state: the result of a random_password (usually a database
565// master password), and an output that sits under a password-like name.
566const TF_RESULT = /("result"\s*:\s*")((?:[^"\\\n]|\\.){3,400})"/g
567const TF_OUTPUT = new RegExp(
568 String.raw`("([\w.-]{1,100})"\s*:\s*\{\s*(?:"(?:sensitive|type)"\s*:\s*[^,{}]{1,40},\s*){0,4}"value"\s*:\s*")((?:[^"\\\n]|\\.){3,400})"`,
569 'g',
570)
571// A name and its value as sibling fields: a HAR header or form field, a
572// Kubernetes env entry. The name decides; the value sits apart from it.
573const JSON_NAME_VALUE = /("name"\s*:\s*"([^"\n]{1,100})"\s*,\s*"value"\s*:\s*")((?:[^"\\\n]|\\.){3,400})"/g
574const JSON_VALUE_NAME = /("value"\s*:\s*")((?:[^"\\\n]|\\.){3,400})("\s*,\s*"name"\s*:\s*"([^"\n]{1,100})")/g
575const YAML_NAME_VALUE =
576 /^([ \t]*)(-[ \t]+name:[ \t]*["']?([\w.-]{1,100})["']?[ \t]*\r?\n\1[ \t]+value:[ \t]*(["']?))([^\n"']{3,200}?)\4[ \t]*(?=\r?$)/gm
577const PW_NAME = new RegExp(String.raw`^[\w.-]*${PW_WORD}$|^(?:[\w.-]*[_.-])?${SHORT_PW}$`, 'i')
578// SQL: an INSERT whose column list names a key or a password.
579const SQL_INSERT = /\bINSERT[ \t]+INTO[ \t]+[\w."`[\]]{1,100}[ \t]*\(([^()\n]{1,1000})\)\s*VALUES\s*/gi
580// `PGPASSWORD=x psql` is the one common env name with no separator.
581const KV_PASSWORD = /((?:^|[\s;&?,])-{0,2}(?:[A-Za-z0-9._-]*[_.-]|pg)?(?:password|passwd)=|[;&?]pwd=)([^\s"'&;,]{3,200})/gim
582
583// A generated password in quotes, with no name beside it: upper, lower,
584// digit and a symbol from the Terraform and password-manager sets, no space,
585// no path or regex characters. The token scan cuts such a value at each
586// symbol, so it is judged whole here.
587// The opening quote must follow a space, `=`, `:`, `(`, `,`, `[` or `{`, so
588// the text between two strings (`"0"=20cellpadding=3D"`) is not taken.
589const QUOTED_VALUE = /(?<=^|[\s:=(,[{])(["'])([^\s"'\\/.,;`]{12,128})\1/gm
590const PW_SYMBOL = /[!#$%&*()=+[\]{}<>:?@^~]/
591
592function looksGenerated(v: string): boolean {
593 if (!/[A-Z]/.test(v) || !/[a-z]/.test(v) || !/[0-9]/.test(v) || !PW_SYMBOL.test(v)) return false
594 if (/\$\{|\{\{|%\(|^\^|\$$|[A-Za-z]-[A-Za-z]\]|=>|::|\(\)|<\/?[a-z]|=[0-9A-F]{2}|[0-9]{6}/.test(v)) return false
595 // Real words in it: code, a format, a shortcut (`Ctrl+Alt+F12`), a payee
596 // with an order number (`Merchant#a12345`).
597 const words = v.match(/[A-Za-z]{4,}/g)?.filter((w) => WORDY.test(w)) ?? []
598 if (words.length >= 2 || words.some((w) => w.length >= 6)) return false
599 // Mostly letters and digits: a run of symbols is binary or markup.
600 if ((v.match(/[A-Za-z0-9]/g)?.length ?? 0) * 5 < v.length * 3) return false
601 return entropy(v) >= 3.5
602}
603
604// Things that stand in for a value without being one: a variable, a call, a
605// template, a placeholder, a type, the key's own name, a path.
606// A call has to close (`getSecret("x")`), and a YAML tag is a word
607// (`!Ref DbPassword`), so a generated password that starts `ab(` or `!` is
608// not taken for one.
609const REFERENCE =
610 /^[A-Za-z_$][\w$.]*\(.*\)[,;]?$|^\$|^\{\{|^<.*>$|^%\(|^!!?[A-Za-z][\w:]*(?:[ \t]|$)|^\*+$|^(?:true|false|null|none|nil|undefined|required|optional|string|str|bool|int|number)$|^(?:process\.env|os\.environ|env\.|config\.|settings\.)|^[A-Za-z_$][\w$]*(?:\.[A-Za-z_$][\w$]*)+$/i
611const SELF_REF =
612 /^[{`(]?(?:[a-z][A-Za-z0-9]*)?(?:Password|Passwd|Secret|Key|Token|Pwd)[A-Za-z0-9]*[)},`]*$|^(?:password|passwd|secret|apikey|api_key|pwd|token)[),}]*,?$/
613const PLACEHOLDER = /^(?:x{3,}|\.{3,}|…|(?:your|my|<)[_ -]?[a-z_ -]*(?:key|password|secret|token)[a-z_ -]*>?)$/i
614
615function isStandIn(v: string): boolean {
616 return (
617 REFERENCE.test(v) ||
618 SELF_REF.test(v) ||
619 PLACEHOLDER.test(v) ||
620 /^(?:[/~]|\.\.?\/)/.test(v) ||
621 /^\{[\w$.]+\}$/.test(v) ||
622 // A test fixture made of words: `test-internal-key`, `fake_secret`.
623 (/^(?:[a-z]+[_-])*(?:test|fake|dummy|mock|sample|example|placeholder|changeme)(?:[_-][a-z]+)*$/.test(v) && /[_-]/.test(v)) ||
624 // `password: pw,` in an object literal is code, not a value.
625 /^[A-Za-z_$][\w$]*,$/.test(v)
626 )
627}
628
629// Credentials on a command line: `--password x`, `curl -u user:pw`,
630// `mysql -pPW`, a .pgpass line, a .netrc entry, `gh secret set --body`.
631const CLI_FLAG =
632 /((?:^|\s)--?(?:password|passwd|pass|api-key|apikey|api_key|token|client-secret|auth-token|access-token)(?:=|[ \t]+)(["']?))(?![$<{%])([^\s"'=-][^\s"']{2,200})\2/g
633const CLI_USERPASS =
634 /(\b(?:curl|wget|http|https|xh|httpie|lftp|ftp)\b[^\n|;&]*?\s(?:-u|-U|--user|--proxy-user)(?:[ \t]+|=)["']?[^\s:"'$]+:)(?!\$)([^\s"'`]{3,200})/g
635const MYSQL_P =
636 /(\b(?:mysql(?:dump|admin|import|sh|check|slap|binlog)?|mariadb(?:-dump|-admin)?)\b[^\n|;&]*?\s-p)(?!\$)([^\s`-][^\s`]{2,200})/g
637const PGPASS =
638 /^((?:\*|[A-Za-z0-9.-]+|\[[0-9A-Fa-f:]+\]):(?:\d{1,5}|\*):(?![0-9]+:)[A-Za-z0-9_$*.-]+:[A-Za-z0-9_$*.@-]+:)(?!\/\/)(\S{3,200})$/gm
639const NETRC =
640 /((?:^|\n)[ \t]*(?:machine[ \t]+\S+|default)(?:\s+(?:login|account|port)[ \t]+\S+)*\s+password[ \t]+)(\S{3,200})(?=[ \t]*(?:\r?\n|$)|\s+(?:machine|default|login|account|macdef)\b)/g
641const GH_SECRET = /(\bgh[ \t]+secret[ \t]+set\b[^\n;&|]*?[ \t](?:-b|--body)(?:[ \t]+|=)(["']?))([^\s"']{3,400})(?=\2)/g
642// Short password flags that only mean a password for one command:
643// `sshpass -p`, `docker login -p`, `mongosh -p`, `7z -pPW`, `sqlcmd -P`,
644// `zip -P`, `redis-cli -a`, `ldapsearch -w`. Each is anchored at its command.
645const CMD_PW_TOOLS: [cmd: string, flag: string][] = [
646 [String.raw`sshpass|(?:docker|podman|nerdctl|helm[ \t]+registry)[ \t]+login|mongo(?:sh|dump|restore|import|export)?`, String.raw`-p[ \t]*`],
647 [String.raw`7za?|7zz`, '-p'],
648 [String.raw`sqlcmd|zip`, String.raw`-P[ \t]+`],
649 [String.raw`redis-cli|valkey-cli`, String.raw`-a[ \t]+`],
650 [String.raw`ldap[a-z]+`, String.raw`-w[ \t]+`],
651]
652const CMD_PW = CMD_PW_TOOLS.map(
653 ([cmd, flag]) => new RegExp(String.raw`(\b(?:${cmd})\b[^\n|;&]*?[ \t]${flag}(["']?))(?![$-])([^\s"']{3,200})\2`, 'g'),
654)
655const CMD_PW_GATE = /sshpass|login|mongo|7z|sqlcmd|zip|redis-cli|valkey-cli|ldap/
656// `openssl ... -passout pass:PW`, `smbclient -U user%PW`, `htpasswd -b file
657// user PW`, `rabbitmqctl add_user user PW`.
658const OPENSSL_PASS = /(-pass(?:in|out)?[ \t]+pass:)([^\s"']{3,200})/g
659const SMB_USER = /(\bsmbclient\b[^\n|;&]*?[ \t]-U[ \t]+["']?[^\s%"']+%)([^\s"']{3,200})/g
660const HTPASSWD = /(\bhtpasswd[ \t]+-[a-zA-Z]*b[a-zA-Z]*[ \t]+(?:-[a-zA-Z]+[ \t]+)*\S+[ \t]+\S+[ \t]+)(["']?)([^\s"']{3,200})\2/g
661const NET_USER = /(\bnet[ \t]+user[ \t]+(?:"[^"\n]{1,64}"|\S+)[ \t]+)(["']?)((?!\/)[^\s"'*]{3,200})\2/gi
662const RABBIT_USER = /(\brabbitmqctl[ \t]+(?:add_user|change_password)[ \t]+\S+[ \t]+)(["']?)([^\s"']{3,200})\2/g
663
664// Cookies: every value in a Cookie header, curl -b, or cookies.txt.
665const COOKIE = /((?:^|["'\s])(?:(?:set-)?cookie["']?[ \t]*:|-b|--cookie)[ \t]*["']?)([^"'\n]*)/gim
666const COOKIE_PAIR = /(^|;[ \t]*)([^=;\s]+=)([^;\s]{16}[^;\s]*)/g
667const COOKIE_ATTR = /^(?:path|domain|expires|max-age|samesite|priority)=$/i
668const COOKIE_VALUE = /^(?:s%3A)?([A-Za-z0-9_+%-]{16}[A-Za-z0-9_+%-]*)(?:\.[A-Za-z0-9_+%/-]{16}[A-Za-z0-9_+%/-]*)?={0,2}$/i
669const COOKIES_TXT =
670 /^((?:#HttpOnly_)?\.?[\w.-]+\t(?:TRUE|FALSE)\t\S+\t(?:TRUE|FALSE)\t\d+\t[^\t\n]+\t)([^\t\r\n]{16}[^\t\r\n]*)$/gm
671const HAR_COOKIE = /("name"\s*:\s*"[^"]*(?:sess|sid|token|auth)[^"]*"\s*,\s*"value"\s*:\s*")([^"]{16}[^"]*)"/gi
672
673// Basic auth and Docker `auth`: base64 of `user:password`, often short.
674const BASIC_AUTH = /((?:["']auth["'][ \t]*:[ \t]*["']|\b[Bb]asic[ \t]+))([A-Za-z0-9+/]{8,200}={0,2})(?![A-Za-z0-9+/=])/g
675// A Kubernetes bootstrap token: `abcdef.0123456789abcdef`.
676const BOOTSTRAP = /\b([a-z0-9]{6})\.([a-z0-9]{16})\b/g
677
678// Inline media in a data: URI. Only media types: a key put in a JSON or text
679// data URI is still scanned. The length floor stops a short key placed after
680// a fake image prefix from being excused.
681const DATA_URI =
682 /data:(?:(?:image|font|audio|video)\/[\w.+-]+|application\/(?:x-)?font-[\w.+-]+|application\/vnd\.ms-fontobject)(?:;[\w-]+=[\w.-]+)*;base64,[A-Za-z0-9+/]{64}[A-Za-z0-9+/]*={0,2}/g
683
684// A base64 blob: one long run, or three or more wrapped lines (a PEM bundle,
685// a MIME part). A trailing short line is only taken when a blank line, a
686// `--boundary` or the end of the text follows it.
687const B64_LINE = String.raw`[A-Za-z0-9+/]{40}[A-Za-z0-9+/]*={0,2}\r?\n`
688const BLOB = new RegExp(
689 String.raw`(?<![A-Za-z0-9+/=])(?:(?:${B64_LINE}){3}(?:${B64_LINE})*(?:[A-Za-z0-9+/]+={0,2}(?=\r?\n[\r\n-]|\r?\n?$))?|[A-Za-z0-9+/]{256}[A-Za-z0-9+/]*={0,2})`,
690 'g',
691)
692const BLOB_NAME =
693 /(?:key|token|secret|password|passwd|credential|auth|private|signature|session|cookie|dsn|cert[_-]?key)[\w.-]*["'\]\s]{0,4}[:=]{1,2}\s*["'`]?\s*$/i
694const BLOB_INNER = /PRIVATE KEY|OPENSSH|"private_key"|"client_secret"|"refresh_token"|"password"|"auths"/
695
696// A Claude thinking-block signature, and a redacted thinking block: opaque
697// to everyone and useless as a credential. Only the value is parked; the
698// thinking text beside it is still scanned.
699const THINKING_SIG =
700 /("type"\s*:\s*"thinking"\s*,\s*"thinking"\s*:\s*"[^"\\]*(?:\\.[^"\\]*)*"\s*,\s*"signature"\s*:\s*")([A-Za-z0-9+/]{200}[A-Za-z0-9+/]*={0,2})(?=")/g
701const REDACTED_THINKING = /("type"\s*:\s*"redacted_thinking"\s*,\s*"data"\s*:\s*")([A-Za-z0-9+/]{100}[A-Za-z0-9+/]*={0,2})(?=")/g
702
703// A lockfile or SRI integrity hash: exact digest lengths only, so a key
704// glued after `sha256-` is still judged.
705const SRI = /\bsha(?:1-[A-Za-z0-9+/]{27}=|256-[A-Za-z0-9+/]{43}=|384-[A-Za-z0-9+/]{64}|512-[A-Za-z0-9+/]{86}==)(?![A-Za-z0-9+/=])/g
706
707// Public font files: the file name is a hash, not a secret. Path characters
708// only, so a query string on the same URL is still scanned.
709const PUBLIC_URL = /https:\/\/fonts\.gstatic\.com\/[A-Za-z0-9_/.-]+/g
710
711// Mail: an optional `cat -n`, Read or `grep -n` prefix on each line.
712const PFX = String.raw`(?:[ \t]*\d+\t|[^\s:]+:\d+[:-])?`
713const PFX_RE = new RegExp(`^${PFX}`)
714const CTE = new RegExp(String.raw`^${PFX}Content-Transfer-Encoding:[ \t]*base64[ \t]*\r?$`, 'gim')
715const CONTENT_TYPE = new RegExp(String.raw`^${PFX}Content-Type:[ \t]*(?:\r?\n${PFX}[ \t]+)?([^;\s]+)`, 'im')
716const MAIL_HEADER_NAMES =
717 'DKIM-Signature|X-Google-DKIM-Signature|ARC-Seal|ARC-Message-Signature|ARC-Authentication-Results|Authentication-Results|Message-I[Dd]|References|In-Reply-To|Feedback-ID|X-SG-EID|X-SG-ID|X-MSFBL|X-Gm-Message-State|X-Google-Smtp-Source|X-Gm-Gg|X-Gm-Features|X-Received|Received-SPF|Return-Path|Received'
718const MAIL_HEADER = new RegExp(String.raw`^${PFX}(?:${MAIL_HEADER_NAMES}):[^\n]*(?:\r?\n${PFX}[ \t][^\n]*){0,12}`, 'gm')
719const HEADER_LINE = new RegExp(String.raw`^${PFX}[A-Z][A-Za-z0-9-]*:`)
720const ENCODED_WORD = /=\?[\w-]+\?[Bb]\?[A-Za-z0-9+/=]{4}[A-Za-z0-9+/=]*\?=/g
721const BOUNDARY = /Content-Type:[ \t]*multipart\/[^\n]*?(?:\r?\n[ \t][^\n]*?)?\bboundary="?([^"\s;]+)"?/gi
722
723// The generic scan. A slash-bearing base64 run (an AWS secret, `openssl rand
724// -base64`) is judged whole first; anything else is cut into candidate
725// tokens. `/` and `.` are left out of a candidate on purpose: with them in,
726// every long file path becomes one. A token never starts inside a `%XX`
727// escape, and `=` only counts as padding when nothing follows it.
728const CAND_BODY = String.raw`[A-Za-z0-9+_-]{12,200}(?:={1,2}(?![A-Za-z0-9=]))?`
729const CANDIDATE_SRC = String.raw`(?<=%[0-9A-Fa-f]{2})(?<!%25)${CAND_BODY}|(?<=%25[0-9A-Fa-f]{2})${CAND_BODY}|(?<!%[0-9A-Fa-f]?|%25[0-9A-Fa-f]?)${CAND_BODY}`
730const SLASHED_SRC = String.raw`(?<![A-Za-z0-9+/_.%~-])[A-Za-z0-9+/]{20,300}={0,2}(?![A-Za-z0-9+/=_.%~-])`
731const CANDIDATE = new RegExp(CANDIDATE_SRC, 'g')
732const SCAN = new RegExp(`(${SLASHED_SRC})|${CANDIDATE_SRC}`, 'g')
733
734// A name to the left of the candidate that says the candidate is a key:
735// `API_KEY=`, `"token":`, an escaped `\"token\":`, `"token":`,
736// `Authorization: Bearer `, `Authorization: <any scheme> `, `--api-key `, a
737// table cell, a YAML block, a Go header map `X-Api-Key:[`, a Python header
738// tuple `('X-Api-Key', '`. `PAT` is a personal access token, not `PATH`.
739const NAME_WORDS =
740 'key|token|secret|password|passwd|pwd|credential|auth|bearer|private|signature|session|cookie|dsn|salt|nonce|otp|sess(?:ion)?[_-]?id|(?<![A-Za-z])sid|(?<![A-Za-z])sig|(?<![A-Za-z])pat(?![a-z])'
741const Q = String.raw`(?:\\{0,3}["'${'`'}]|&(?:quot|apos|#0*3[49]|#x0*2[27]);|\\u00(?:22|27))`
742const NAMED = new RegExp(
743 '(?:' +
744 String.raw`(?:${NAME_WORDS})(?:(?<=key)[_-]?id)?(?:${Q}|\]|\s){0,6}[:=]{1,2}(?:${Q}|\s){0,4}\[?` +
745 String.raw`|(?:${NAME_WORDS})[\w-]{0,20}${Q}[ \t]*,[ \t]*${Q}` +
746 String.raw`|\bbearer[ \t]+["']?` +
747 String.raw`|authorization["']?[ \t]*[:=][ \t]*["']?(?:[A-Za-z][\w-]{0,31}[ \t]+)?` +
748 String.raw`|(?:^|\s)--?(?![a-z_-]*(?:public|pub|cache|idempotency|signing|recv)[_-]?key)[a-z_-]*(?:key|token|secret|password|passwd|pw|auth)[ \t]+["']?` +
749 String.raw`|\|[ \t]*[\w.-]*(?:key|token|secret|password)[ \t]*\|[ \t]*` +
750 String.raw`|(?:key|token|secret|password|passwd|pwd|credential|auth)[\w-]*["']?[ \t]*:[ \t]*[>|][-+1-9]{0,2}[ \t]*\r?\n[ \t]+` +
751 ')$',
752 'i',
753)
754
755// A sibling field name that makes its value a key: the value is then
756// judged as if the name stood right before it.
757const KEY_NAME = new RegExp(String.raw`(?:${NAME_WORDS}|authorization)`, 'i')
758
759const HEX_ONLY = /^[0-9a-f]+$/i
760const PREFIXED_KEY = /^[a-z]{2,12}(?:_v[0-9])?[_-]([a-z0-9]{32,})$/
761const DIGITS_ONLY = /^[0-9]+$/
762const LETTERS_ONLY = /^[A-Za-z]+$/
763
764// Public ids with a shape rather than a prefix: a YouTube channel or
765// playlist, a Monzo transaction, a Vercel deployment, team or project, an
766// OpenAI org, a Claude Code session, environment or server tool call. Exact
767// lengths only, and the Anthropic ids start `01`, so any other token after
768// the same prefix is still judged.
769const PUBLIC_SHAPE =
770 /^(?:UC[A-Za-z0-9_-]{22}|PL[A-Za-z0-9_-]{16,32}|(?:tx|mm|acc|pot|merch|user)_0000[A-Za-z0-9]{18}|dpl_[A-Za-z0-9]{24,32}|org-[A-Za-z0-9]{24}|team_[A-Za-z0-9]{24}|prj_[A-Za-z0-9]{28}|(?:session|env|srvtoolu)_01[A-Za-z0-9]{22})$/
771
772// Prefixes that name a PUBLIC object id, not a key. Stripe hands these out in
773// dashboards, invoices and source code; hiding them makes a session useless
774// and protects nothing. `pk_live_` is Stripe's publishable key, also public.
775const PUBLIC_PREFIX =
776 /^(?:price|prod|cus|sub|sched|in|ch|pi|cs|py|re|txn|il|si|seti|evt|acct|promo|coupon|plan|card|ba|src|dp|du|iv|ii|rcpt|file|link|pm|tok|pk|test|toolu|msg|req|run|wf)_/i
777// A public id is the prefix, maybe `live_` or `test_`, then one alnum body.
778// `prod_api_key_<random>` is not that shape, so it is judged like any token.
779const PUBLIC_ID_BODY = /^(?:(?:live|test)_)?[A-Za-z0-9]+$/
780// A WooCommerce consumer secret reuses Stripe's `cs_`; Stripe's never is
781// 40 lowercase hex.
782// A Klaviyo private key reuses `pk_`, with no `live_` or `test_` after it.
783const NOT_PUBLIC = /^cs_[a-f0-9]{40}$|^pk_(?!live_|test_)[A-Za-z0-9]{34}$/
784// Generic prefixes a key name in front may override (`API_KEY=test_...`).
785const SOFT_PUBLIC = /^(?:test|tok)_/i
786
787// A name written in code (`archived-modules-marker`, `handleCheckoutSession`,
788// `lesson_article_outline_open_v1`) reads as high entropy but is a word list.
789// A key is not built out of words.
790const WORD_PART = /^(?:[a-z]+[0-9]{0,3}|[A-Z][a-z]+[0-9]{0,3}|[A-Z]{2,})$/
791const ALNUM_ONLY = /^[A-Za-z0-9]+$/
792const SEGMENTS = /[A-Z]+(?![a-z])|[A-Z]?[a-z]+|[0-9]+/g
793const WORDY = /^[A-Za-z]?[a-z]{2,}$/
794const SLASH_WORD = /^(?:[a-z]+[0-9]{0,3}|[A-Z][a-z]+[0-9]{0,3})$/
795const STRICT_CAMEL = /^(?:[a-z]{2,}|[A-Z][a-z]{2,})(?:[A-Z][a-z]{2,})+[0-9]{0,3}$/
796
797// `playerEventBatchV1Schema` splits into six segments of which four are
798// words; a random key splits into many segments of which almost none are.
799// A camel name has a capital in it: an all-lowercase token with a digit run
800// in the middle is a random value more often than a name.
801function isCamelName(token: string): boolean {
802 if (!ALNUM_ONLY.test(token) || !/[A-Z]/.test(token)) return false
803 const segs = token.match(SEGMENTS)
804 if (!segs || segs.join('') !== token) return false
805 const words = segs.filter((seg) => WORDY.test(seg)).length
806 return words >= 2 && words >= segs.length - 2
807}
808
809// Every character used once AND mostly in alphabet order: a charset constant.
810// The order test matters: a random 24-character key has all distinct
811// characters about 1% of the time.
812function isAlphabet(token: string): boolean {
813 if (token.length < 20) return false
814 let runs = 0
815 for (let i = 1; i < token.length; i++) if (token.charCodeAt(i) === token.charCodeAt(i - 1) + 1) runs++
816 return runs * 2 >= token.length && new Set(token).size === token.length
817}
818
819// Half or more of the characters follow the one before in code order:
820// `0123456789abcdef`, the base64 alphabet. A sample in docs, never a key.
821function countsUp(s: string): boolean {
822 let runs = 0
823 for (let i = 1; i < s.length; i++) if (s.charCodeAt(i) === s.charCodeAt(i - 1) + 1) runs++
824 return runs * 2 >= s.length
825}
826
827function isMixed(s: string): boolean {
828 return /[a-z]/.test(s) && /[A-Z]/.test(s) && /[0-9]/.test(s)
829}
830
831// One word, or a number of up to four digits (a year, a month, a day).
832function isSlugPart(part: string): boolean {
833 return WORD_PART.test(part) || /^[0-9]{1,4}$/.test(part)
834}
835
836// A part made only of words, short acronyms and short numbers: `expenseID`,
837// `2026`, `v2Final`. It names something; it is not a random remainder.
838function isWordish(part: string): boolean {
839 const segs = part.match(SEGMENTS)
840 if (!segs || segs.join('') !== part) return false
841 return segs.every((seg) => WORDY.test(seg) || /^[A-Z]{2,4}$/.test(seg) || /^[0-9]{1,4}$/.test(seg))
842}
843
844function looksLikeName(token: string, named: boolean): boolean {
845 if (isCamelName(token)) return true
846 // A name beside the token outweighs the alphabet rule.
847 if (!named && isAlphabet(token)) return true
848 const parts = token.split(/[_-]/)
849 if (parts.length < 2) return false
850 // Beside a key's name, one key-like part makes the whole token a key:
851 // `django-insecure-<random>`, `live-secret-<random>`.
852 if (named && parts.some((p) => p.length >= 16 && /[0-9]/.test(p) && /[A-Za-z]/.test(p) && entropy(p) >= 3.0)) return false
853 // A long random remainder outweighs any words in front of it
854 // (`vercel_blob_rw_<random>`, `dckr_pat_<random>`). Mixed case is asked
855 // for, so a hex cache key or a timestamp is not a remainder.
856 const residue = parts.filter((p) => !WORD_PART.test(p) && !isCamelName(p) && !isWordish(p)).join('')
857 // Words plus one long number (a LinkedIn post slug, a Zoom recording, an
858 // Amazon ref tag): the number is an id, not part of a random remainder.
859 // Only the parts that are neither words, numbers nor date stamps count,
860 // and camel parts are not excused here, since a random string can pass
861 // the camel test.
862 const longNumber = !named && parts.some((p) => /^[A-Z]{0,4}[0-9]{6,}$/.test(p))
863 const randomPart = longNumber ? parts.filter((p) => !WORD_PART.test(p) && !/^[0-9]{1,4}$/.test(p) && !DIGITS_ONLY.test(p) && !DATE_STAMP.test(p)).join('') : ''
864 if ((longNumber ? (randomPart.length >= 8 ? 16 : 0) : residue.length) >= 16 && isMixed(residue)) return false
865 // Words, dates and short numbers only (`2025-08-26-lesson`): a slug.
866 if (parts.every(isSlugPart)) return true
867 // Three or more separated parts, two of them plain words: a naming
868 // convention (`META_Conv_Lookalike-Customers_FreeTrial_2024Q1`), not a key.
869 if (parts.length >= 3 && parts.filter((p) => /^[A-Za-z]{4,}$/.test(p)).length >= 2) return true
870 return longNumber && randomPart.length < 8
871}
872const DATE_STAMP = /^[A-Z]{0,4}(?:19|20)[0-9]{6}$/
873
874function isPublicId(token: string, named: boolean, cfg: Config): boolean {
875 if (PUBLIC_SHAPE.test(token)) return true
876 if (cfg.allowPrefix.some((p) => token.startsWith(p))) return true
877 if (!PUBLIC_PREFIX.test(token) || NOT_PUBLIC.test(token)) return false
878 if (cfg.denyPrefix.some((p) => token.startsWith(p))) return false
879 if (named && SOFT_PUBLIC.test(token)) return false
880 return PUBLIC_ID_BODY.test(token.replace(PUBLIC_PREFIX, ''))
881}
882
883// A letters-only key (no digit at all) splits into many short camel
884// segments; a camel name of the same length splits into a few long ones.
885function lettersLookRandom(token: string, named: boolean, h: number): boolean {
886 if (!LETTERS_ONLY.test(token) || !/[a-z]/.test(token) || !/[A-Z]/.test(token)) return false
887 const segs = token.match(SEGMENTS) ?? []
888 if (named && token.length >= 20 && h >= 3.6 && segs.length * 4 >= token.length) return true
889 return token.length >= 24 && h >= 4.0 && segs.length * 3 >= token.length
890}
891
892// Claude Code transcripts and most analytics put a `sessionId` UUID on every
893// line. A UUID beside that name is an identifier, not a credential; a real
894// session cookie is random text, and the cookie rules hide it on their own.
895const SESSION_UUID = new RegExp(`^${UUID}$`, 'i')
896const SESSION_ID_NAME = new RegExp(String.raw`sess(?:ion)?[_-]?id(?:${Q}|\s){0,6}[:=]{1,2}(?:${Q}|\s){0,4}$`, 'i')
897
898function looksSecret(token: string, before: string, cfg: Config): boolean {
899 if (token.startsWith('REDACTED-')) return false
900 if (cfg.allow.has(token) || DIGITS_ONLY.test(token)) return false
901 const named = NAMED.test(before)
902 if (isPublicId(token, named, cfg)) return false
903 // `invoice+statements+acct_<id>`: a mail sender address made of words and
904 // a public id. Each `+` part has to be one, so base64 is still judged.
905 if (token.includes('+') && token.split('+').every((p) => p === '' || WORD_PART.test(p) || isPublicId(p, named, cfg))) return false
906 if (named && SESSION_UUID.test(token) && SESSION_ID_NAME.test(before)) return false
907 if (looksLikeName(token, named)) return false
908
909 const h = entropy(token)
910
911 // A bare hex run is a git SHA or a checksum far more often than it is a
912 // key, so hex needs a name beside it before it is hidden.
913 if (HEX_ONLY.test(token)) return named && token.length >= 24 && h >= cfg.contextMinEntropy
914
915 // A short lowercase prefix and a long random body (imp_ and 40 hex): a
916 // vendor key no rule names. A git SHA has no prefix, so it is not caught here.
917 const prefixed = token.match(PREFIXED_KEY)
918 if (prefixed && /[0-9]/.test(prefixed[1]!) && /[a-z]/.test(prefixed[1]!) && entropy(prefixed[1]!) >= cfg.contextMinEntropy) return true
919
920 if (isMixed(token) && token.length >= cfg.minLength && h >= cfg.minEntropy) return true
921 if (lettersLookRandom(token, named, h)) return true
922 // Next to a key's name the bar is lower, but the token still has to look
923 // like a key: letters and digits together, not a word.
924 const alnum = /[0-9]/.test(token) && /[A-Za-z]/.test(token)
925 return named && alnum && token.length >= 16 && h >= cfg.contextMinEntropy
926}
927
928// A slash-bearing base64 run, judged on the parts that are not words, so a
929// path like `uploads/2026/10/12/Report2Final` stays a path.
930function slashedSecret(run: string, named: boolean, cfg: Config): boolean {
931 if (cfg.allow.has(run)) return false
932 const body = run.replace(/=+$/, '').replace(/^\/+/, '')
933 if (!body.includes('/') || !isMixed(body) || countsUp(body)) return false
934 const parts = body.split('/').filter(Boolean)
935 const isWord = (p: string): boolean => SLASH_WORD.test(p) || STRICT_CAMEL.test(p) || DIGITS_ONLY.test(p)
936 const words = parts.filter(isWord).length
937 if (words * 2 >= parts.length) return false
938 if (!isMixed(parts.filter((p) => !isWord(p)).join(''))) return false
939 const h = entropy(body)
940 return (body.length >= 32 && h >= 4.3) || (named && body.length >= 16 && h >= 3.6)
941}
942
943// -------------------------------------------------------------- the passes
944
945// Mints `value` unless it is already a placeholder, allowed, or a stand-in.
946function pairOut(cfg: Config, head: string, value: string, tail = ''): string {
947 if (WHOLE_TAG.test(value) || cfg.allow.has(value) || isStandIn(value)) return head + value + tail
948 return head + mint('SECRET', value) + tail
949}
950
951function parkOpaque(text: string): string {
952 let out = text
953 if (out.includes('"signature"')) out = out.replace(THINKING_SIG, (_m, head: string, sig: string) => head + park(sig))
954 if (out.includes('redacted_thinking')) out = out.replace(REDACTED_THINKING, (_m, head: string, data: string) => head + park(data))
955 if (out.includes('sha')) out = out.replace(SRI, (m) => park(m))
956 return out
957}
958
959function scrubKeyBlocks(text: string, cfg: Config): string {
960 let out = text
961 if (out.includes('PRIVATE KEY')) out = out.replace(PRIVATE_KEY, (m) => (cfg.allow.has(m) ? m : mint('SECRET', m)))
962 if (out.includes('Private-Lines:')) out = out.replace(PUTTY_PRIVATE, (_m, head: string, body: string) => head + mint('SECRET', body))
963 return out
964}
965
966// Walks the dot-separated parts of a run: a part holding `eyJ` and the two
967// parts after it are a JWT, when each is long enough.
968function scrubJwtChain(chain: string, cfg: Config): string {
969 if (!chain.includes('eyJ')) return chain
970 const segs = chain.split('.')
971 const out: string[] = []
972 let k = 0
973 while (k < segs.length) {
974 const i = k + 2 < segs.length ? segs[k]!.indexOf('eyJ') : -1
975 if (i >= 0 && segs[k]!.length - i >= 11 && segs[k + 1]!.length >= 8 && segs[k + 2]!.length >= 8) {
976 const jwt = `${segs[k]!.slice(i)}.${segs[k + 1]}.${segs[k + 2]}`
977 out.push(segs[k]!.slice(0, i) + (cfg.allow.has(jwt) ? jwt : mint('SECRET', jwt)))
978 k += 3
979 } else {
980 out.push(segs[k]!)
981 k += 1
982 }
983 }
984 return out.join('.')
985}
986
987// `postgres://user:REDACTED@host` in docs: the word itself stands in for one.
988const URL_PASSWORD_WORD = /^(?:password|passwd|pass|pw|pwd|secret|<[^>]*>)$/i
989
990function scrubUrls(text: string, cfg: Config): string {
991 let out = text
992 if (out.includes('://')) {
993 out = out.replace(URL_PASSWORD, (m, head: string, password: string) =>
994 WHOLE_TAG.test(password) || cfg.allow.has(password) || URL_PASSWORD_WORD.test(password) ? m : `${head}:${mint('SECRET', password)}@`,
995 )
996 out = out.replace(URL_USERINFO, (m, head: string, user: string) => {
997 if (cfg.allow.has(user) || !/[0-9]/.test(user) || !/[A-Za-z]/.test(user) || looksLikeName(user, true)) return m
998 return entropy(user) >= cfg.contextMinEntropy ? `${head}${mint('SECRET', user)}@` : m
999 })
1000 }
1001 if (out.includes('=')) {
1002 out = out.replace(URL_PARAM, (m, head: string, value: string) => (urlParamSecret(value, cfg) ? head + mint('SECRET', value) : m))
1003 }
1004 return out
1005}
1006
1007function urlParamSecret(raw: string, cfg: Config): boolean {
1008 if (cfg.allow.has(raw)) return false
1009 let v = raw
1010 try {
1011 v = decodeURIComponent(raw)
1012 } catch {
1013 // A broken escape: judge it as it stands.
1014 }
1015 if (cfg.allow.has(v) || v.length < 12) return false
1016 if ([/[a-z]/, /[A-Z]/, /[0-9]/, /[^A-Za-z0-9]/].filter((r) => r.test(v)).length < 2) return false
1017 if (looksLikeName(v, true)) return false
1018 return entropy(v) >= cfg.contextMinEntropy
1019}
1020
1021function scrubCommandLines(text: string, cfg: Config): string {
1022 let out = text
1023 if (/-(?:pass|api|token|client|auth|access)/.test(out)) {
1024 out = out.replace(CLI_FLAG, (m, head: string, quote: string, v: string) => {
1025 if (/^[A-Z][A-Z0-9_]*$/.test(v) || /^[A-Za-z_]+=/.test(v) || /^[A-Za-z]+(?:[-_][A-Za-z]+)+$/.test(v)) return m
1026 return pairOut(cfg, head, v, quote)
1027 })
1028 }
1029 if (/\s-(?:u|U|-user|-proxy-user)\b/.test(out)) {
1030 out = out.replace(CLI_USERPASS, (m, head: string, v: string) => (DIGITS_ONLY.test(v) ? m : pairOut(cfg, head, v)))
1031 }
1032 if (/mysql|mariadb/.test(out)) out = out.replace(MYSQL_P, (_m, head: string, v: string) => pairOut(cfg, head, v))
1033 if (out.includes(':')) out = out.replace(PGPASS, (_m, head: string, v: string) => pairOut(cfg, head, v))
1034 if (out.includes('password')) out = out.replace(NETRC, (_m, head: string, v: string) => pairOut(cfg, head, v))
1035 if (out.includes('gh')) out = out.replace(GH_SECRET, (_m, head: string, _q: string, v: string) => pairOut(cfg, head, v))
1036 if (CMD_PW_GATE.test(out)) {
1037 for (const re of CMD_PW) out = out.replace(re, (_m, head: string, q: string, v: string) => pairOut(cfg, head, v, q))
1038 }
1039 if (out.includes('pass:')) out = out.replace(OPENSSL_PASS, (_m, head: string, v: string) => pairOut(cfg, head, v))
1040 if (out.includes('smbclient')) out = out.replace(SMB_USER, (_m, head: string, v: string) => pairOut(cfg, head, v))
1041 if (out.includes('htpasswd')) out = out.replace(HTPASSWD, (_m, head: string, q: string, v: string) => pairOut(cfg, head, v, q))
1042 if (/net[ \t]+user/i.test(out)) out = out.replace(NET_USER, (_m, head: string, q: string, v: string) => pairOut(cfg, head, v, q))
1043 if (out.includes('rabbitmqctl')) out = out.replace(RABBIT_USER, (_m, head: string, q: string, v: string) => pairOut(cfg, head, v, q))
1044 return out
1045}
1046
1047function scrubAssignments(text: string, cfg: Config): string {
1048 let out = text
1049 // A value under a key that says it is public is left: a publishable key.
1050 const value = (head: string, key: string, v: string, tail = ''): string => {
1051 if (/public|publishable/i.test(key)) return head + v + tail
1052 if (PUBLIC_PREFIX.test(v) && !/secret|private/i.test(key) && isPublicId(v, false, cfg)) return head + v + tail
1053 if (shortKeyStatus(key, v)) return head + v + tail
1054 return pairOut(cfg, head, v, tail)
1055 }
1056 // A value whose name sits in a sibling field.
1057 const sibling = (head: string, name: string, v: string, tail = ''): string => {
1058 if (PW_NAME.test(name)) return value(head, name, v, tail)
1059 if (KEY_NAME.test(name) && !/public|publishable/i.test(name) && looksSecret(v, 'key=', cfg)) return head + mint('SECRET', v) + tail
1060 return head + v + tail
1061 }
1062 if (/pass|secret|key|token|pw/i.test(out)) {
1063 out = out.replace(STRONG_QUOTED, (_m, head: string, _q: string, key: string, quote: string, v: string) => value(head + quote, key, v, quote))
1064 out = out.replace(APP_PASSWORD, (_m, head: string, v: string) => pairOut(cfg, head, v))
1065 out = out.replace(STRONG_LINE, (_m, head: string, key: string, v: string) => value(head, key, v))
1066 out = out.replace(ENV_PASS, (_m, head: string, _k: string, v: string) => value(head, '', v))
1067 out = out.replace(BLOCK_PASSWORD, (_m, head: string, v: string) => pairOut(cfg, head, v))
1068 out = out.replace(KV_PASSWORD, (_m, head: string, v: string) => pairOut(cfg, head, v))
1069 }
1070 if (PW_SYMBOL.test(out)) {
1071 out = out.replace(QUOTED_VALUE, (m, q: string, v: string, offset: number, whole: string) => {
1072 if (!looksGenerated(v) || isStandIn(v) || cfg.allow.has(v)) return m
1073 // A MIME boundary is random by design and public.
1074 if (/boundary=$/i.test(whole.slice(Math.max(0, offset - 9), offset))) return m
1075 return q + mint('SECRET', v) + q
1076 })
1077 }
1078 if (/password|identified/i.test(out)) out = out.replace(SQL_PASSWORD, (_m, head: string, v: string) => pairOut(cfg, head + "'", v, "'"))
1079 if (out.includes('variable')) out = out.replace(HCL_DEFAULT, (_m, head: string, v: string) => pairOut(cfg, head, v, '"'))
1080 if (out.includes('"value"')) {
1081 out = out.replace(JSON_NAME_VALUE, (_m, head: string, name: string, v: string) => sibling(head, name, v, '"'))
1082 out = out.replace(JSON_VALUE_NAME, (_m, head: string, v: string, tail: string, name: string) => sibling(head, name, v, tail))
1083 out = out.replace(TF_OUTPUT, (_m, head: string, name: string, v: string) => (PW_NAME.test(name) ? value(head, name, v, '"') : _m))
1084 }
1085 if (/"random_(?:password|string)"/.test(out)) {
1086 out = out.replace(TF_RESULT, (m, head: string, v: string) => (WHOLE_TAG.test(v) || cfg.allow.has(v) ? m : `${head}${mint('SECRET', v)}"`))
1087 }
1088 if (/-[ \t]+name:/.test(out)) {
1089 out = out.replace(YAML_NAME_VALUE, (_m, indent: string, head: string, name: string, q: string, v: string) => sibling(indent + head, name, v, q))
1090 }
1091 if (/INSERT[ \t]+INTO/i.test(out)) out = scrubSqlInserts(out, cfg)
1092 return out
1093}
1094
1095// The VALUES rows after an INSERT whose columns name a key or a password:
1096// the value in that column is hidden. Bounded to 100 rows and 20,000
1097// characters per INSERT. Quoted values only; a number is never a key.
1098function scrubSqlInserts(text: string, cfg: Config): string {
1099 const ranges: [number, number][] = []
1100 for (const m of text.matchAll(SQL_INSERT)) {
1101 const names = m[1]!.split(',').map((c) => c.trim().replace(/^[`"[]|[`"\]]$/g, ''))
1102 const kinds = names.map((n) => (PW_NAME.test(n) ? 'pw' : KEY_NAME.test(n) && !/(?:^|_)id$|public/i.test(n) ? 'key' : ''))
1103 if (!kinds.some(Boolean)) continue
1104 const limit = Math.min(text.length, m.index! + m[0].length + 20_000)
1105 let i = m.index! + m[0].length
1106 const skipSpace = (): void => {
1107 while (i < limit && /\s/.test(text[i]!)) i++
1108 }
1109 for (let row = 0; row < 100 && text[i] === '('; row++) {
1110 i++
1111 for (let col = 0; i < limit && text[i] !== ')'; col++) {
1112 skipSpace()
1113 if (text[i] === "'") {
1114 const from = ++i
1115 while (i < limit && !(text[i] === "'" && text[i + 1] !== "'")) i += text[i] === "'" ? 2 : 1
1116 const v = text.slice(from, i)
1117 i++
1118 const kind = kinds[col]
1119 if (kind && v.length >= 3 && !cfg.allow.has(v) && (kind === 'pw' ? !isStandIn(v) : looksSecret(v, 'key=', cfg))) ranges.push([from, from + v.length])
1120 } else {
1121 while (i < limit && text[i] !== ',' && text[i] !== ')') i++
1122 }
1123 skipSpace()
1124 if (text[i] === ',') i++
1125 else break
1126 }
1127 if (text[i] !== ')') break
1128 i++
1129 skipSpace()
1130 if (text[i] !== ',') break
1131 i++
1132 skipSpace()
1133 }
1134 }
1135 if (ranges.length === 0) return text
1136 const parts: string[] = []
1137 let last = 0
1138 for (const [from, to] of ranges) {
1139 if (from < last) continue
1140 parts.push(text.slice(last, from), mint('SECRET', text.slice(from, to)))
1141 last = to
1142 }
1143 parts.push(text.slice(last))
1144 return parts.join('')
1145}
1146
1147function cookieSecret(raw: string, cfg: Config): boolean {
1148 if (cfg.allow.has(raw) || raw.includes('[REDACTED-')) return false
1149 const m = raw.match(COOKIE_VALUE)
1150 if (!m) return false
1151 const body = m[1]!
1152 if (looksLikeName(body, true)) return false
1153 return /[0-9]/.test(body) && /[A-Za-z]/.test(body) && entropy(body) >= cfg.contextMinEntropy
1154}
1155
1156function scrubCookies(text: string, cfg: Config): string {
1157 let out = text
1158 if (/cookie|-b\s/i.test(out)) {
1159 out = out.replace(COOKIE, (_m, head: string, header: string) =>
1160 head +
1161 header.replace(COOKIE_PAIR, (pair, sep: string, name: string, v: string) =>
1162 !COOKIE_ATTR.test(name) && cookieSecret(v, cfg) ? sep + name + mint('SECRET', v) : pair,
1163 ),
1164 )
1165 }
1166 if (out.includes('\t')) out = out.replace(COOKIES_TXT, (m, head: string, v: string) => (cookieSecret(v, cfg) ? head + mint('SECRET', v) : m))
1167 if (out.includes('"value"')) out = out.replace(HAR_COOKIE, (m, head: string, v: string) => (cookieSecret(v, cfg) ? `${head}${mint('SECRET', v)}"` : m))
1168 return out
1169}
1170
1171function scrubAuthBlobs(text: string, cfg: Config): string {
1172 let out = text
1173 if (/asic|"auth"|'auth'/.test(out)) {
1174 out = out.replace(BASIC_AUTH, (m, head: string, v: string) => {
1175 if (v.length % 4 !== 0 || cfg.allow.has(v)) return m
1176 return /^[\x21-\x7e]+:[\x20-\x7e]+$/.test(decodeBase64Head(v)) ? head + mint('SECRET', v) : m
1177 })
1178 }
1179 if (out.includes('.')) {
1180 out = out.replace(BOOTSTRAP, (m, id: string, secret: string, offset: number, whole: string) => {
1181 if (!/[0-9]/.test(secret) || !/[a-z]/.test(secret) || countsUp(secret)) return m
1182 return NAMED.test(whole.slice(Math.max(0, offset - 64), offset)) ? `${id}.${mint('SECRET', secret)}` : m
1183 })
1184 }
1185 return out
1186}
1187
1188// The decoded start of a base64 text is text, not media: almost no control
1189// bytes. An image or random bytes fail this at once, and a PDF or a zip
1190// (docx, xlsx) is known by its first bytes, so the full decode below only
1191// runs on encoded text.
1192function decodesToText(b64: string): boolean {
1193 const head = decodeBase64Head(b64, 512)
1194 if (head.length < 8 || head.startsWith('%PDF') || head.startsWith('PK\x03\x04')) return false
1195 let control = 0
1196 for (let i = 0; i < head.length; i++) {
1197 const c = head.charCodeAt(i)
1198 if ((c < 32 && c !== 9 && c !== 10 && c !== 13) || c === 127) control++
1199 }
1200 return control * 50 <= head.length