2015-12-19 14:41:39 +01:00
|
|
|
File Format
|
|
|
|
|
===========
|
|
|
|
|
|
|
|
|
|
Header
|
|
|
|
|
|
|
|
|
|
2 bytes header version (big endian uint16, currently 2)
|
|
|
|
|
16 bytes file id
|
|
|
|
|
|
|
|
|
|
Data block
|
|
|
|
|
|
|
|
|
|
16 bytes GCM IV (nonce)
|
|
|
|
|
1-4096 bytes encrypted data
|
|
|
|
|
16 bytes GHASH
|
|
|
|
|
|
2018-07-15 11:24:54 +02:00
|
|
|
Full block overhead = 32/4096 = 1/128 = 0.78125 %
|
2015-12-19 14:41:39 +01:00
|
|
|
|
|
|
|
|
Example: 1-byte file
|
|
|
|
|
--------------------
|
|
|
|
|
|
|
|
|
|
Header 18 bytes
|
|
|
|
|
Data block 33 bytes
|
|
|
|
|
|
|
|
|
|
Total: 51 bytes
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Example: 5000-byte file
|
|
|
|
|
-----------------------
|
|
|
|
|
|
|
|
|
|
Header 18 bytes
|
|
|
|
|
Data block 4128 bytes
|
|
|
|
|
Data block 936 bytes
|
|
|
|
|
|
|
|
|
|
Total: 5082 bytes
|
