Dev Tunnels SSH Keys Library

Enables importing and exporting SSH public and private keys in various formats. Password-protection of private keys is also supported when importing and exporting some formats.

Supported Key Algorithms

• RSA (2048, 4096)
• ECDSA (P-256, P-384, P-521)

Supported Key Formats

• SSH public key - Single line starting with a key algorithm name such as ssh-rsa, followed by base64-encoded key bytes, and an optional comment. Files in this format typically end with .pub.

• PKCS#1 public or private RSA key - PEM-encoded keys in this format begin with one of the following:
  -----BEGIN RSA PUBLIC KEY-----
-----BEGIN RSA PRIVATE KEY-----

• SEC1 private EC key - PEM-encoded keys in this format begin with:
  -----BEGIN EC PRIVATE KEY-----

• PKCS#8 public or private key - PEM-encoded keys in this format begin with one of the following:
  -----BEGIN PUBLIC KEY-----
-----BEGIN PRIVATE KEY-----
-----BEGIN ENCRYPTED PRIVATE KEY-----

• JSON Web Key (JWK) - Key paramters are formatted as JSON.

Private keys in PKCS#1, SEC1, or PKCS#8 format may be passphrase-protected, meaning the private key is encrypted using an encryption key derived from a passphrase. (The encryption used by the PKCS#1/SEC1 formats is weak and no longer recommended.)

For the key formats that are typically PEM-encoded, the equivalent binary (DER) format is also supported.

Example

Use importKey*, exportPublicKey*, and exportPrivateKey* functions provided by the library to import or export keys. When importing, the key format can be auto-detected in most cases.

// Import my password-protected RSA private key from a file.
const privateKey: KeyPair = importPrivateKeyFile('.ssh/id_rsa', myPassword);

// Use the private key for client public key authentication.
const session: SshClientSession = ...
const credentials: SshClientCredentials = { username, publicKeys: [ privateKey ] };
const result: boolean = await session.authenticate(credentials);

When exporting, you can specify the format, and optionally supply a password for encrypting the key. The default format is PKCS#8 because it has broad support and strong encryption when using password protection.