nostr-nsec-seedphrase
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A comprehensive TypeScript library for Nostr key management with BIP39 seed phrases, supporting both ESM and CommonJS. Implements NIP-01, NIP-06, NIP-19, and NIP-26 with key generation, event signing, bech32 encoding/decoding, and secure cryptographic ope
208 lines (207 loc) • 7.14 kB
JavaScript
/**
* @module crypto/keys
* @description Key management functions for Nostr
*/
import { generateMnemonic, validateMnemonic, mnemonicToEntropy } from "bip39";
import { secp256k1, schnorr } from "@noble/curves/secp256k1.js";
import { bytesToHex, hexToBytes } from "@noble/hashes/utils.js";
import { sha256 } from "@noble/hashes/sha2.js";
import { logger } from "../utils/logger.js";
import { hexToNpub, hexToNsec } from "../nips/nip-19.js";
/**
* Gets the compressed public key (33 bytes with prefix)
*/
function getCompressedPublicKey(privateKeyBytes) {
return secp256k1.getPublicKey(privateKeyBytes, true);
}
/**
* Gets the schnorr public key (32 bytes x-coordinate) as per BIP340
*/
function getSchnorrPublicKey(privateKeyBytes) {
return schnorr.getPublicKey(privateKeyBytes);
}
/**
* Creates a PublicKeyDetails object from a hex string
*/
export function createPublicKey(hex) {
const bytes = hexToBytes(hex);
// For schnorr, we need to remove the first byte (compression prefix)
const schnorrBytes = bytes.length === 33 ? bytes.slice(1) : bytes;
return {
hex,
compressed: bytes.length === 33 ? bytes : getCompressedPublicKey(bytes),
schnorr: schnorrBytes,
npub: hexToNpub(hex),
};
}
/**
* Generates a new BIP39 seed phrase
* @returns A random 12-word BIP39 mnemonic seed phrase
*/
export function generateSeedPhrase() {
logger.log("Generating new seed phrase");
return generateMnemonic(128); // 12 words
}
/**
* Converts a BIP39 seed phrase to its entropy value
* @param seedPhrase - The BIP39 seed phrase to convert
* @returns The entropy value
* @throws {Error} If the seed phrase is invalid
*/
export function getEntropyFromSeedPhrase(seedPhrase) {
try {
if (!validateMnemonic(seedPhrase)) {
throw new Error("Invalid seed phrase");
}
return hexToBytes(mnemonicToEntropy(seedPhrase));
}
catch (error) {
logger.error("Failed to get entropy from seed phrase:", error?.toString());
throw error;
}
}
/**
* Validates a BIP39 seed phrase
* @param seedPhrase - The seed phrase to validate
* @returns True if the seed phrase is valid, false otherwise
*/
export function validateSeedPhrase(seedPhrase) {
logger.log("Validating seed phrase");
const isValid = validateMnemonic(seedPhrase);
logger.log({ isValid }, "Validated seed phrase");
return Boolean(isValid);
}
/**
* Converts a BIP39 seed phrase to a Nostr key pair
* @param seedPhrase - The BIP39 seed phrase to convert
* @returns A key pair containing private and public keys in various formats
* @throws {Error} If the seed phrase is invalid or key generation fails
*/
export async function seedPhraseToKeyPair(seedPhrase) {
try {
if (!validateSeedPhrase(seedPhrase)) {
throw new Error("Invalid seed phrase");
}
const entropy = getEntropyFromSeedPhrase(seedPhrase);
const privateKey = derivePrivateKey(entropy);
entropy.fill(0); // zero sensitive material
const privateKeyBytes = hexToBytes(privateKey);
const publicKey = createPublicKey(bytesToHex(getCompressedPublicKey(privateKeyBytes)));
privateKeyBytes.fill(0); // zero sensitive material
return {
privateKey,
publicKey,
nsec: hexToNsec(privateKey),
seedPhrase,
};
}
catch (error) {
logger.error("Failed to convert seed phrase to key pair:", error?.toString());
throw error;
}
}
/**
* Derives a private key from entropy
* @param {Uint8Array} entropy - The entropy to derive from
* @returns {string} The hex-encoded private key
*/
export function derivePrivateKey(entropy) {
try {
// Hash the entropy to get a valid private key
const privateKeyBytes = sha256(entropy);
const hex = bytesToHex(privateKeyBytes);
privateKeyBytes.fill(0); // zero sensitive material
return hex;
}
catch (error) {
logger.error("Failed to derive private key:", error?.toString());
throw new Error("Failed to derive private key");
}
}
/**
* Generates a new key pair with a random seed phrase
* @returns A new key pair containing private and public keys in various formats
*/
export async function generateKeyPairWithSeed() {
const seedPhrase = generateSeedPhrase();
return seedPhraseToKeyPair(seedPhrase);
}
/**
* Creates a key pair from a hex private key
* @param privateKeyHex - The hex-encoded private key
* @returns A key pair containing private and public keys in various formats
* @throws {Error} If the private key is invalid
*/
export async function fromHex(privateKeyHex) {
try {
const privateKeyBytes = hexToBytes(privateKeyHex);
if (!secp256k1.utils.isValidSecretKey(privateKeyBytes)) {
privateKeyBytes.fill(0); // zero sensitive material
throw new Error("Invalid private key");
}
const publicKey = createPublicKey(bytesToHex(getCompressedPublicKey(privateKeyBytes)));
privateKeyBytes.fill(0); // zero sensitive material
return {
privateKey: privateKeyHex,
publicKey,
nsec: hexToNsec(privateKeyHex),
seedPhrase: "", // No seed phrase for hex-imported keys
};
}
catch (error) {
logger.error("Failed to create key pair from hex:", error?.toString());
throw error;
}
}
/**
* Validates a key pair
* @param publicKey - The public key to validate
* @param privateKey - The private key to validate
* @returns Validation result
*/
export async function validateKeyPair(publicKey, privateKey) {
try {
const privateKeyBytes = hexToBytes(privateKey);
if (!secp256k1.utils.isValidSecretKey(privateKeyBytes)) {
privateKeyBytes.fill(0); // zero sensitive material
return {
isValid: false,
error: "Invalid private key",
};
}
const pubKeyHex = typeof publicKey === "string" ? publicKey : publicKey.hex;
const derivedPublicKey = bytesToHex(getCompressedPublicKey(privateKeyBytes));
privateKeyBytes.fill(0); // zero sensitive material
if (pubKeyHex !== derivedPublicKey) {
return {
isValid: false,
error: "Public key does not match private key",
};
}
return {
isValid: true,
};
}
catch (error) {
logger.error("Failed to validate key pair:", error?.toString());
return {
isValid: false,
error: error instanceof Error ? error.message : "Unknown error",
};
}
}
/**
* Validates a Nostr public key
* @param publicKey - The public key to validate
* @returns True if valid, false otherwise
*/
export function validatePublicKey(publicKey) {
try {
const bytes = hexToBytes(publicKey);
return bytes.length === 32 || bytes.length === 33;
}
catch (error) {
logger.error("Failed to validate public key:", error?.toString());
return false;
}
}