diff options
Diffstat (limited to 'node/Packet.hpp')
| -rw-r--r-- | node/Packet.hpp | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/node/Packet.hpp b/node/Packet.hpp index 4859dafd..b736b84a 100644 --- a/node/Packet.hpp +++ b/node/Packet.hpp @@ -1353,16 +1353,18 @@ public: /** * Encrypt/decrypt a separately armored portion of a packet * - * This keys using the same key in the same way as armor/dearmor, but - * uses a different IV computed from the packet's IV plus the starting - * point index. - * * This currently uses Salsa20/12, but any message that uses this should - * incorporate a cipher selector to permit this to be changed later. + * incorporate a cipher selector to permit this to be changed later. To + * ensure that key stream is not reused, the key is slightly altered for + * this use case and the same initial 32 keystream bytes that are taken + * for MAC in ordinary armor() are also skipped here. * * This is currently only used to mask portions of HELLO as an extra * security precation since most of that message is sent in the clear. * + * This must NEVER be used more than once in the same packet, as doing + * so will result in re-use of the same key stream. + * * @param key 32-byte key * @param start Start of encrypted portion * @param len Length of encrypted portion |