pr_01m47d24b0e6n91zwymwxg0vpx/services/identity/src/crypto.ts
| 1 | // Workers cap PBKDF2 at 100,000 iterations. |
| 2 | const PBKDF2_ITERATIONS = 100_000; |
| 3 | |
| 4 | const encoder = new TextEncoder(); |
| 5 | |
| 6 | export function toHex(bytes: ArrayBuffer | Uint8Array): string { |
| 7 | return [...new Uint8Array(bytes)] |
| 8 | .map((byte) => byte.toString(16).padStart(2, "0")) |
| 9 | .join(""); |
| 10 | } |
| 11 | |
| 12 | export function fromBase64(value: string): Uint8Array<ArrayBuffer> { |
| 13 | return Uint8Array.from(atob(value), (char) => char.charCodeAt(0)); |
| 14 | } |
| 15 | |
| 16 | export function toBase64(bytes: ArrayBuffer | Uint8Array): string { |
| 17 | return btoa(String.fromCharCode(...new Uint8Array(bytes))); |
| 18 | } |
| 19 | |
| 20 | export async function sha256Hex(value: string): Promise<string> { |
| 21 | return toHex(await crypto.subtle.digest("SHA-256", encoder.encode(value))); |
| 22 | } |
| 23 | |
| 24 | export function randomHex(bytes: number): string { |
| 25 | return toHex(crypto.getRandomValues(new Uint8Array(bytes))); |
| 26 | } |
| 27 | |
| 28 | async function pbkdf2( |
| 29 | password: string, |
| 30 | salt: Uint8Array<ArrayBuffer>, |
| 31 | iterations: number, |
| 32 | ): Promise<Uint8Array> { |
| 33 | const key = await crypto.subtle.importKey( |
| 34 | "raw", |
| 35 | encoder.encode(password), |
| 36 | "PBKDF2", |
| 37 | false, |
| 38 | ["deriveBits"], |
| 39 | ); |
| 40 | return new Uint8Array( |
| 41 | await crypto.subtle.deriveBits( |
| 42 | { name: "PBKDF2", hash: "SHA-256", salt, iterations }, |
| 43 | key, |
| 44 | 256, |
| 45 | ), |
| 46 | ); |
| 47 | } |
| 48 | |
| 49 | /** Format: `pbkdf2$<iterations>$<salt base64>$<hash base64>`. */ |
| 50 | export async function hashPassword(password: string): Promise<string> { |
| 51 | const salt = crypto.getRandomValues(new Uint8Array(16)); |
| 52 | const hash = await pbkdf2(password, salt, PBKDF2_ITERATIONS); |
| 53 | return `pbkdf2$${PBKDF2_ITERATIONS}$${toBase64(salt)}$${toBase64(hash)}`; |
| 54 | } |
| 55 | |
| 56 | export async function verifyPassword( |
| 57 | password: string, |
| 58 | stored: string, |
| 59 | ): Promise<boolean> { |
| 60 | const [scheme, iterations, salt, hash] = stored.split("$"); |
| 61 | if (scheme !== "pbkdf2") return false; |
| 62 | const expected = fromBase64(hash); |
| 63 | const given = await pbkdf2(password, fromBase64(salt), Number(iterations)); |
| 64 | // Constant-time comparison. |
| 65 | let diff = given.length ^ expected.length; |
| 66 | for (let i = 0; i < expected.length; i++) diff |= given[i] ^ expected[i]; |
| 67 | return diff === 0; |
| 68 | } |
| 69 | |
| 70 | /** |
| 71 | * Parses an OpenSSH public key line. The fingerprint matches |
| 72 | * `ssh-keygen -lf` (SHA256, unpadded base64). |
| 73 | */ |
| 74 | export async function parseSshKey( |
| 75 | line: string, |
| 76 | ): Promise<{ publicKey: string; fingerprint: string; comment: string } | null> { |
| 77 | const [type, blob, ...comment] = line.trim().split(/\s+/); |
| 78 | if (!/^(ssh-(ed25519|rsa)|ecdsa-sha2-nistp(256|384|521))$/.test(type ?? "")) { |
| 79 | return null; |
| 80 | } |
| 81 | let bytes: Uint8Array<ArrayBuffer>; |
| 82 | try { |
| 83 | bytes = fromBase64(blob ?? ""); |
| 84 | // The blob starts with its own length-prefixed copy of the key type. |
| 85 | const typeLength = new DataView(bytes.buffer).getUint32(0); |
| 86 | if (new TextDecoder().decode(bytes.slice(4, 4 + typeLength)) !== type) { |
| 87 | return null; |
| 88 | } |
| 89 | } catch { |
| 90 | return null; |
| 91 | } |
| 92 | const digest = await crypto.subtle.digest("SHA-256", bytes); |
| 93 | return { |
| 94 | publicKey: `${type} ${blob}`, |
| 95 | fingerprint: `SHA256:${toBase64(digest).replace(/=+$/, "")}`, |
| 96 | comment: comment.join(" "), |
| 97 | }; |
| 98 | } |