Function DecryptJoinAccept

pkg/crypto/join_messages.go:50–63

DecryptJoinAccept uses AES Encrypt to decrypt a join-accept message - The returned payload contains JoinNonce/AppNonce | NetID | DevAddr | DLSettings | RxDelay | (CFList | CFListType) | MIC - In LoRaWAN 1.0, the AppKey is used - In LoRaWAN 1.1, the NwkKey or JSEncKey is used

(key types.AES128Key, encrypted []byte)

// - In LoRaWAN 1.0, the AppKey is used
// - In LoRaWAN 1.1, the NwkKey or JSEncKey is used
func DecryptJoinAccept(key types.AES128Key, encrypted []byte) ([]byte, error) {
	if len(encrypted) != 16 && len(encrypted) != 32 {
		return nil, errInvalidJoinAcceptMessageSize.WithAttributes("size", len(encrypted))
	}
	cipher, err := aes.NewCipher(key[:])
	if err != nil {
		return nil, err
	}
	payload := make([]byte, len(encrypted))
	for i := 0; i < len(encrypted); i += 16 {
		cipher.Encrypt(payload[i:i+16], encrypted[i:i+16])
	}
	return payload, nil
}

var errInvalidJoinRequestPayloadSize = errInvalidSize("join_request_payload", "join-request payload", "19")