Add optional cipher/hmac algo remodulate on rekey

This commit is contained in:
Russ Magee 2023-12-02 01:58:30 -08:00
parent e82d968381
commit 32b669192b
6 changed files with 103 additions and 11 deletions

View file

@ -530,12 +530,14 @@ func main() { //nolint:funlen,gocyclo
var dbg bool
var laddr string
var rekeySecs uint
var remodSupported bool // true: when rekeying, switch to random cipher/hmac alg
var useSystemPasswd bool
flag.BoolVar(&vopt, "v", false, "show version")
flag.UintVar(&rekeySecs, "r", 300, "rekey interval in `secs`")
flag.StringVar(&laddr, "l", ":2000", "interface[:port] to listen") //nolint:gomnd,lll
flag.BoolVar(&remodSupported, "R", false, "Borg Countermeasures (remodulate cipher/hmac alg on each rekey)")
flag.StringVar(&laddr, "l", ":2000", "interface[:port] to listen") //nolint:gomnd,lll
flag.StringVar(&kcpMode, "K", "unused", `set to one of ["KCP_NONE","KCP_AES", "KCP_BLOWFISH", "KCP_CAST5", "KCP_SM4", "KCP_SALSA20", "KCP_SIMPLEXOR", "KCP_TEA", "KCP_3DES", "KCP_TWOFISH", "KCP_XTEA"] to use KCP (github.com/xtaci/kcp-go) reliable UDP instead of TCP`) //nolint:lll
flag.BoolVar(&useSysLogin, "L", false, "use system login")
flag.BoolVar(&chaffEnabled, "e", true, "enable chaff pkts")
@ -702,6 +704,22 @@ func main() { //nolint:funlen,gocyclo
} else {
log.Println("Accepted client")
// Only enable cipher alg changes on re-key if we were told
// to support it (launching xsd with -R), *and* the client
// proposes to use it.
if !remodSupported {
if (conn.Opts() & xsnet.CORemodulateShields) != 0 {
logger.LogDebug("[client proposed cipher/hmac remod, but we don't support it.]")
conn.Close()
continue
}
} else {
if conn.Opts()&xsnet.CORemodulateShields != 0 {
logger.LogDebug("[cipher/hmac remodulation active]")
} else {
logger.LogDebug("[cipher/hmac remodulation inactive]")
}
}
conn.RekeyHelper(rekeySecs)
// Set up chaffing to client