Something went wrong. Try again.
A collaborative coding-agent orchestrator for atproto radl.app
Something went wrong. Try again.
TypeScript
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252// Per-forge operator credentials. GitHub's lives in `github-auth.ts` (a `gh` token, resolved from// the environment or the CLI); tangled's is an ed25519 SSH key this file generates, stores and// formats.//// Boundary 5 holds: an `sh.tangled.publicKey` is a GIT TRANSPORT credential. It authenticates a// push to a knot and nothing else — it cannot sign atproto records and cannot reach a PDS — so it is// scopeable and expendable exactly like `GH_TOKEN`, and revoked by deleting one record. What it can// do is push as the agent DID to any repository that DID may write to, which is the same bound// design §10 already accepts for the GitHub token.
import { generateKeyPairSync } from 'node:crypto'import { chmod, lstat, mkdir, readFile, rename, writeFile } from 'node:fs/promises'import { dirname, join } from 'node:path'
/** An ed25519 keypair in the two encodings ssh and tangled want. */export interface SshKeyPair { /** OpenSSH private key file contents (`-----BEGIN OPENSSH PRIVATE KEY-----`), unencrypted. */ privateKey: string /** `ssh-ed25519 <base64> <comment>` — the line an `sh.tangled.publicKey` record carries. */ publicKey: string}
const encoder = new TextEncoder()
function sshString(value: Uint8Array | string): Uint8Array { const bytes = typeof value === 'string' ? encoder.encode(value) : value const out = new Uint8Array(4 + bytes.length) new DataView(out.buffer).setUint32(0, bytes.length) out.set(bytes, 4) return out}
function concat(chunks: Uint8Array[]): Uint8Array { const out = new Uint8Array(chunks.reduce((total, chunk) => total + chunk.length, 0)) let offset = 0 for (const chunk of chunks) { out.set(chunk, offset) offset += chunk.length } return out}
const wrap = (base64: string, width = 70): string => (base64.match(new RegExp(`.{1,${width}}`, 'g')) ?? []).join('\n')
const BASE64_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
/** Standard padded base64. Hand-rolled for the same reason the rest of this workspace hand-rolls * its primitives: no third-party runtime dependency, and `Buffer` is not in the daemon's typed * surface. */function base64(bytes: Uint8Array): string { let out = '' for (let index = 0; index < bytes.length; index += 3) { const a = bytes[index] as number const b = bytes[index + 1] const c = bytes[index + 2] const triple = (a << 16) | ((b ?? 0) << 8) | (c ?? 0) out += BASE64_ALPHABET[(triple >> 18) & 63] out += BASE64_ALPHABET[(triple >> 12) & 63] out += b === undefined ? '=' : BASE64_ALPHABET[(triple >> 6) & 63] out += c === undefined ? '=' : BASE64_ALPHABET[triple & 63] } return out}
/** * A fresh ed25519 keypair, written in OpenSSH's own `openssh-key-v1` container rather than PKCS#8. * * Node can only export PKCS#8/SPKI, and whether a given OpenSSH build will read a PKCS#8 ed25519 * private key depends on how it was compiled — a dependency that would surface as an opaque push * failure inside a container on somebody else's machine. The container format is ~40 lines of * length-prefixed fields and is what `ssh -i` reads everywhere, so it is built here explicitly. */export function generateSshKeyPair(comment: string): SshKeyPair { const { publicKey, privateKey } = generateKeyPairSync('ed25519') // The raw 32-byte halves: SPKI and PKCS#8 both end with them for ed25519. const spki = new Uint8Array(publicKey.export({ format: 'der', type: 'spki' })) const pkcs8 = new Uint8Array(privateKey.export({ format: 'der', type: 'pkcs8' })) const rawPublic = spki.slice(spki.length - 32) const seed = pkcs8.slice(pkcs8.length - 32)
const keyType = 'ssh-ed25519' const publicBlob = concat([sshString(keyType), sshString(rawPublic)]) // OpenSSH's private half stores seed||public as one 64-byte string. const secret = concat([seed, rawPublic]) // `checkint` twice: OpenSSH's own integrity marker for the (here unencrypted) private section. const check = new Uint8Array(8) const checkValue = 0x72616469 // "radi" new DataView(check.buffer).setUint32(0, checkValue) new DataView(check.buffer).setUint32(4, checkValue) let privateSection = concat([ check, sshString(keyType), sshString(rawPublic), sshString(secret), sshString(comment), ]) // Padded to the cipher block size (8 for "none") with 1,2,3… const padding: number[] = [] for (let index = 1; (privateSection.length + padding.length) % 8 !== 0; index += 1) padding.push(index) privateSection = concat([privateSection, Uint8Array.from(padding)])
const numberOfKeys = new Uint8Array(4) new DataView(numberOfKeys.buffer).setUint32(0, 1) const container = concat([ encoder.encode('openssh-key-v1\0'), sshString('none'), // ciphername sshString('none'), // kdfname sshString(''), // kdfoptions numberOfKeys, sshString(publicBlob), sshString(privateSection), ])
return { privateKey: `-----BEGIN OPENSSH PRIVATE KEY-----\n${wrap(base64(container))}\n-----END OPENSSH PRIVATE KEY-----\n`, publicKey: `${keyType} ${base64(publicBlob)} ${comment}`, }}
function base64Decode(text: string): Uint8Array { const clean = text.replace(/[^A-Za-z0-9+/]/g, '') const out = new Uint8Array(Math.floor((clean.length * 3) / 4)) let bits = 0 let value = 0 let offset = 0 for (const character of clean) { const index = BASE64_ALPHABET.indexOf(character) if (index === -1) continue value = (value << 6) | index bits += 6 if (bits >= 8) { bits -= 8 out[offset] = (value >> bits) & 0xff offset += 1 } } return out.slice(0, offset)}
/** * The `ssh-ed25519 …` line for a private key already on disk — how an existing key is re-published * without regenerating it, which would silently invalidate every collaborator grant an operator had * already been given. * * It reads the `openssh-key-v1` container directly rather than through `createPrivateKey`: Node's * OpenSSL decoder does not know that format, and the public half is right there in the container's * fifth field anyway. */export function publicKeyLine(privateKeyFile: string, comment: string): string { const body = /-----BEGIN OPENSSH PRIVATE KEY-----([\s\S]*?)-----END OPENSSH PRIVATE KEY-----/.exec( privateKeyFile, )?.[1] if (!body) throw new Error('not an OpenSSH private key file') const bytes = base64Decode(body) const magic = 'openssh-key-v1\0' if (new TextDecoder().decode(bytes.slice(0, magic.length)) !== magic) { throw new Error('not an openssh-key-v1 private key') } const view = new DataView(bytes.buffer, bytes.byteOffset, bytes.byteLength) let offset = magic.length const next = (): Uint8Array => { const length = view.getUint32(offset) offset += 4 const slice = bytes.slice(offset, offset + length) offset += length return slice } next() // ciphername next() // kdfname next() // kdfoptions offset += 4 // number of keys const publicBlob = next() if (new TextDecoder().decode(publicBlob.slice(4, 4 + 11)) !== 'ssh-ed25519') { throw new Error('only ed25519 tangled push keys are supported') } return `ssh-ed25519 ${base64(publicBlob)} ${comment}`}
/** * The agent's tangled push key on disk, beside `sessions.json` in the operator's XDG state dir and * under the same discipline `FileSessionStore` uses: 0600, a refused symlink, an atomic rename. * Keyed by agent DID, so an operator running several identities does not share one push credential * between them. */export class TangledKeyStore { readonly directory: string
constructor(directory: string) { this.directory = join(directory, 'tangled-keys') }
pathFor(did: string): string { // A DID is `did:method:specific-id`; the specific-id may hold characters a path should not. return join(this.directory, `${did.replace(/[^A-Za-z0-9.:_-]/g, '_')}.key`) }
async read(did: string): Promise<string | undefined> { const path = this.pathFor(did) try { const info = await lstat(path) if (info.isSymbolicLink() || !info.isFile()) { throw new Error(`Tangled key path is not a regular non-symlink file: ${path}`) } if ((info.mode & 0o077) !== 0) await chmod(path, 0o600) return await readFile(path, 'utf8') } catch (error) { if ((error as { code?: string })?.code === 'ENOENT') return undefined throw error } }
async write(did: string, privateKey: string): Promise<string> { const path = this.pathFor(did) await mkdir(dirname(path), { recursive: true, mode: 0o700 }) await chmod(dirname(path), 0o700) const temporary = `${path}.tmp-${Math.random().toString(36).slice(2)}` await writeFile(temporary, privateKey, { mode: 0o600 }) await chmod(temporary, 0o600) await rename(temporary, path) await chmod(path, 0o600) return path }
/** Adopt an existing key, or generate one. Idempotent by design: regenerating would silently * invalidate every collaborator grant an operator had already been given. */ async ensure(did: string, comment: string): Promise<{ pair: SshKeyPair; created: boolean }> { const existing = await this.read(did) if (existing) return { pair: { privateKey: existing, publicKey: publicKeyLine(existing, comment) }, created: false } const pair = generateSshKeyPair(comment) await this.write(did, pair.privateKey) return { pair, created: true } }}
/** * The pinned host keys a tangled push verifies against. There is no default and no fallback: an * unpinned `StrictHostKeyChecking=no` would make every push MITM-able, and guessing a host key here * would be the same mistake with extra steps. The operator supplies the lines (from * `ssh-keyscan tangled.org`, checked against tangled's published fingerprints) in `radial.json`. */export function knownHostsFile(entries: readonly string[]): string { const lines = entries.map((entry) => entry.trim()).filter((entry) => entry.length > 0) if (lines.length === 0) { throw new Error( 'no knownHosts configured for the tangled forge: add "knownHosts" (ssh-keyscan output) to the ' + 'run.forges tangled entry — Radial will not disable host-key checking for you', ) } return `${lines.join('\n')}\n`}