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| author | Adam Ierymenko <adam.ierymenko@gmail.com> | 2013-10-18 17:39:48 -0400 |
|---|---|---|
| committer | Adam Ierymenko <adam.ierymenko@gmail.com> | 2013-10-18 17:39:48 -0400 |
| commit | 8c9b73f67b786d9c08ffc98cc4b0f9b7c44b7717 (patch) | |
| tree | d75961901641f1d35ed51e604e3fe0fa7e8cb6a2 /node/Packet.hpp | |
| parent | 37e3bc3467d0f0648abe9dfb51f558465211fa87 (diff) | |
| download | infinitytier-8c9b73f67b786d9c08ffc98cc4b0f9b7c44b7717.tar.gz infinitytier-8c9b73f67b786d9c08ffc98cc4b0f9b7c44b7717.zip | |
Make Salsa20 variable-round, allowing for Salsa20/12 to be used for Packet encrypt and decrypt. Profiling analysis found that Salsa20 encrypt was accounting for a nontrivial percentage of CPU time, so it makes sense to cut this load fundamentally. There are no published attacks against Salsa20/12, and DJB believes 20 rounds to be overkill. This should be more than enough for our needs. Obviously incorporating ASM Salsa20 is among the next steps for performance.
Diffstat (limited to 'node/Packet.hpp')
| -rw-r--r-- | node/Packet.hpp | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/node/Packet.hpp b/node/Packet.hpp index 486faebb..aeb5d0bb 100644 --- a/node/Packet.hpp +++ b/node/Packet.hpp @@ -92,6 +92,11 @@ */ #define ZT_PROTO_VERB_FLAG_COMPRESSED 0x80 +/** + * Rounds used for Salsa20 encryption in ZT + */ +#define ZT_PROTO_SALSA20_ROUNDS 12 + // Indices of fields in normal packet header -- do not change as this // might require both code rework and will break compatibility. #define ZT_PACKET_IDX_IV 0 @@ -852,7 +857,7 @@ public: else (*this)[ZT_PACKET_IDX_FLAGS] &= (char)(~ZT_PROTO_FLAG_ENCRYPTED); _mangleKey((const unsigned char *)key,mangledKey); - Salsa20 s20(mangledKey,256,field(ZT_PACKET_IDX_IV,8)); + Salsa20 s20(mangledKey,256,field(ZT_PACKET_IDX_IV,8),ZT_PROTO_SALSA20_ROUNDS); // MAC key is always the first 32 bytes of the Salsa20 key stream // This is the same construction DJB's NaCl library uses @@ -880,7 +885,7 @@ public: unsigned char *const payload = field(ZT_PACKET_IDX_VERB,payloadLen); _mangleKey((const unsigned char *)key,mangledKey); - Salsa20 s20(mangledKey,256,field(ZT_PACKET_IDX_IV,8)); + Salsa20 s20(mangledKey,256,field(ZT_PACKET_IDX_IV,8),ZT_PROTO_SALSA20_ROUNDS); s20.encrypt(ZERO_KEY,macKey,sizeof(macKey)); Poly1305::compute(mac,payload,payloadLen,macKey); |