Keychain options

[richardschneider]

The default keychain options should be in config under Keychain.

const defaultOptions = {
  // See https://cryptosense.com/parametesr-choice-for-pbkdf2/
  dek: {
    keyLength: 512 / 8,
    iterationCount: 10000,
    salt: 'you should override this value with a crypto secure random number',
    hash: 'sha512'
  }
}

• ipfs init should generate a random salt and add to config
• during startup, these value should be used to construct the keychain

[daviddias]

@richardschneider did you really want to close this one?

[richardschneider]

@diasdavid the code has been implemented in PR #1133, so why not.