diff options
Diffstat (limited to 'include/olm/ratchet.hh')
-rw-r--r-- | include/olm/ratchet.hh | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/olm/ratchet.hh b/include/olm/ratchet.hh index 13f7097..e91d634 100644 --- a/include/olm/ratchet.hh +++ b/include/olm/ratchet.hh @@ -21,8 +21,13 @@ struct _olm_cipher; namespace olm { -typedef std::uint8_t SharedKey[olm::KEY_LENGTH]; +/** length of a shared key: the root key R(i), chain key C(i,j), and message key + * M(i,j)). They are all only used to stuff into HMACs, so could be any length + * for that. The chain key and message key are both derived from SHA256 + * operations, so their length is determined by that. */ +const std::size_t OLM_SHARED_KEY_LENGTH = SHA256_OUTPUT_LENGTH; +typedef std::uint8_t SharedKey[OLM_SHARED_KEY_LENGTH]; struct ChainKey { std::uint32_t index; |