Golang MetaStore.GetTimestampKey方法代碼示例

// GetOrCreateTimestampKey returns the timestamp key for the gun. It uses the store to
// lookup an existing timestamp key and the crypto to generate a new one if none is
// found. It attempts to handle the race condition that may occur if 2 servers try to
// create the key at the same time by simply querying the store a second time if it
// receives a conflict when writing.
func GetOrCreateTimestampKey(gun string, store storage.MetaStore, crypto signed.CryptoService, fallBackAlgorithm data.KeyAlgorithm) (data.PublicKey, error) {
	keyAlgorithm, public, err := store.GetTimestampKey(gun)
	if err == nil {
		return data.NewPublicKey(keyAlgorithm, public), nil
	}

	if _, ok := err.(*storage.ErrNoKey); ok {
		key, err := crypto.Create("timestamp", fallBackAlgorithm)
		if err != nil {
			return nil, err
		}
		logrus.Debug("Creating new timestamp key for ", gun, ". With algo: ", key.Algorithm())
		err = store.SetTimestampKey(gun, key.Algorithm(), key.Public())
		if err == nil {
			return key, nil
		}

		if _, ok := err.(*storage.ErrTimestampKeyExists); ok {
			keyAlgorithm, public, err = store.GetTimestampKey(gun)
			if err != nil {
				return nil, err
			}
			return data.NewPublicKey(keyAlgorithm, public), nil
		}
		return nil, err
	}
	return nil, err
}

// GetOrCreateTimestampKey returns the timestamp key for the gun. It uses the store to
// lookup an existing timestamp key and the crypto to generate a new one if none is
// found. It attempts to handle the race condition that may occur if 2 servers try to
// create the key at the same time by simply querying the store a second time if it
// receives a conflict when writing.
func GetOrCreateTimestampKey(gun string, store storage.MetaStore, crypto signed.CryptoService, fallBackAlgorithm data.KeyAlgorithm) (*data.TUFKey, error) {
	keyAlgorithm, public, err := store.GetTimestampKey(gun)
	if err == nil {
		return data.NewTUFKey(keyAlgorithm, public, nil), nil
	}

	if _, ok := err.(*storage.ErrNoKey); ok {
		key, err := crypto.Create("timestamp", fallBackAlgorithm)
		if err != nil {
			return nil, err
		}
		err = store.SetTimestampKey(gun, key.Algorithm(), key.Public())
		if err == nil {
			return &key.TUFKey, nil
		}

		if _, ok := err.(*storage.ErrTimestampKeyExists); ok {
			keyAlgorithm, public, err = store.GetTimestampKey(gun)
			if err != nil {
				return nil, err
			}
			return data.NewTUFKey(keyAlgorithm, public, nil), nil
		}
		return nil, err
	}
	return nil, err
}

// CreateTimestamp creates a new timestamp. If a prev timestamp is provided, it
// is assumed this is the immediately previous one, and the new one will have a
// version number one higher than prev. The store is used to lookup the current
// snapshot, this function does not save the newly generated timestamp.
func CreateTimestamp(gun string, prev *data.SignedTimestamp, snapshot []byte, store storage.MetaStore, cryptoService signed.CryptoService) (*data.Signed, int, error) {
	algorithm, public, err := store.GetTimestampKey(gun)
	if err != nil {
		// owner of gun must have generated a timestamp key otherwise
		// we won't proceed with generating everything.
		return nil, 0, err
	}
	key := data.NewPublicKey(algorithm, public)
	sn := &data.Signed{}
	err = json.Unmarshal(snapshot, sn)
	if err != nil {
		// couldn't parse snapshot
		return nil, 0, err
	}
	ts, err := data.NewTimestamp(sn)
	if err != nil {
		return nil, 0, err
	}
	if prev != nil {
		ts.Signed.Version = prev.Signed.Version + 1
	}
	sgndTs, err := cjson.Marshal(ts.Signed)
	if err != nil {
		return nil, 0, err
	}
	out := &data.Signed{
		Signatures: ts.Signatures,
		Signed:     sgndTs,
	}
	err = signed.Sign(cryptoService, out, key)
	if err != nil {
		return nil, 0, err
	}
	return out, ts.Signed.Version, nil
}

// GetOrCreateTimestampKey returns the timestamp key for the gun. It uses the store to
// lookup an existing timestamp key and the crypto to generate a new one if none is
// found. It attempts to handle the race condition that may occur if 2 servers try to
// create the key at the same time by simply querying the store a second time if it
// receives a conflict when writing.
func GetOrCreateTimestampKey(gun string, store storage.MetaStore, crypto signed.CryptoService) (*data.TUFKey, error) {
	cipher, public, err := store.GetTimestampKey(gun)
	if err == nil {
		return data.NewTUFKey(cipher, public, nil), nil
	}

	if _, ok := err.(*storage.ErrNoKey); ok {
		key, err := crypto.Create("timestamp")
		if err != nil {
			return nil, err
		}
		err = store.SetTimestampKey(gun, key.Cipher(), key.Public())
		if err == nil {
			return &key.TUFKey, nil
		}

		if _, ok := err.(*storage.ErrTimestampKeyExists); ok {
			cipher, public, err = store.GetTimestampKey(gun)
			if err != nil {
				return nil, err
			}
			return data.NewTUFKey(cipher, public, nil), nil
		}
		return nil, err
	}
	return nil, err
}