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GSS_WRAP_OVERHEAD_BYTES

Constant GSS_WRAP_OVERHEAD_BYTES 

Source
pub const GSS_WRAP_OVERHEAD_BYTES: usize = 72;
Expand description

GSS wrap token overhead per compound RPC (RFC 4121 S4.2.6.2).

Breakdown:

  • 16B: GSS token header (TOK_ID + Flags + Filler + EC + RR + SND_SEQ)
  • 16B: AES confounder (prepended to plaintext before encryption)
  • 12B: HMAC-SHA1-96 integrity check value
  • ~28B: XDR alignment padding and GSS framing overhead Total: ~72B per compound body

This overhead is already accounted for in KRB5P_MAX_WRITE_DATA (3584B), which is empirically derived to stay safely below the 3952B AES-CTS block boundary (247 x 16B AES blocks).