Function parseDER

lib/protocol/keyParser.js:1312–1391

(data, baseType, comment, fullType)

function parseDER(data, baseType, comment, fullType) {
  if (!isSupportedKeyType(baseType))
    return new Error(`Unsupported OpenSSH public key type: ${baseType}`);

  let algo;
  let oid;
  let pubPEM = null;
  let pubSSH = null;

  switch (baseType) {
    case 'ssh-rsa': {
      const e = readString(data, data._pos || 0);
      if (e === undefined)
        return new Error('Malformed OpenSSH public key');
      const n = readString(data, data._pos);
      if (n === undefined)
        return new Error('Malformed OpenSSH public key');
      pubPEM = genOpenSSLRSAPub(n, e);
      pubSSH = genOpenSSHRSAPub(n, e);
      algo = 'sha1';
      break;
    }
    case 'ssh-dss': {
      const p = readString(data, data._pos || 0);
      if (p === undefined)
        return new Error('Malformed OpenSSH public key');
      const q = readString(data, data._pos);
      if (q === undefined)
        return new Error('Malformed OpenSSH public key');
      const g = readString(data, data._pos);
      if (g === undefined)
        return new Error('Malformed OpenSSH public key');
      const y = readString(data, data._pos);
      if (y === undefined)
        return new Error('Malformed OpenSSH public key');
      pubPEM = genOpenSSLDSAPub(p, q, g, y);
      pubSSH = genOpenSSHDSAPub(p, q, g, y);
      algo = 'sha1';
      break;
    }
    case 'ssh-ed25519': {
      const edpub = readString(data, data._pos || 0);
      if (edpub === undefined || edpub.length !== 32)
        return new Error('Malformed OpenSSH public key');
      pubPEM = genOpenSSLEdPub(edpub);
      pubSSH = genOpenSSHEdPub(edpub);
      algo = null;
      break;
    }
    case 'ecdsa-sha2-nistp256':
      algo = 'sha256';
      oid = '1.2.840.10045.3.1.7';
    // FALLTHROUGH
    case 'ecdsa-sha2-nistp384':
      if (algo === undefined) {
        algo = 'sha384';
        oid = '1.3.132.0.34';
      }