2015-12-19 14:41:39 +01:00
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File Format
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===========
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Header
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2 bytes header version (big endian uint16, currently 2)
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16 bytes file id
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2019-01-04 19:31:41 +01:00
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Data block, default AES-GCM mode
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2015-12-19 14:41:39 +01:00
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16 bytes GCM IV (nonce)
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1-4096 bytes encrypted data
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16 bytes GHASH
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2019-01-05 02:10:03 +01:00
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Data block, AES-SIV mode (used in reverse mode, or when explicitly enabled with `-init -aessiv`)
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2019-01-04 19:31:41 +01:00
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16 bytes nonce
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16 bytes SIV
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1-4096 bytes encrypted data
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2018-07-15 11:24:54 +02:00
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Full block overhead = 32/4096 = 1/128 = 0.78125 %
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2015-12-19 14:41:39 +01:00
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Example: 1-byte file
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--------------------
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Header 18 bytes
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Data block 33 bytes
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Total: 51 bytes
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Example: 5000-byte file
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-----------------------
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Header 18 bytes
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Data block 4128 bytes
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Data block 936 bytes
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Total: 5082 bytes
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