func NewCircuit(id CircuitID, fSeed, bSeed, fKey, bKey []byte) *Circuit {
if id == 0 {
panic("wtf?")
}
StatsNewCircuit()
aes_fwd := aes.New(fKey, zeroIv[:])
aes_rev := aes.New(bKey, zeroIv[:])
dig_fwd := sha1.New()
dig_fwd.Write(fSeed)
dig_rev := sha1.New()
dig_rev.Write(bSeed)
circ := &Circuit{
id: id,
forward: DirectionalCircuitState{
cipher: aes_fwd,
digest: dig_fwd,
},
backward: DirectionalCircuitState{
cipher: aes_rev,
digest: dig_rev,
},
backwardWindow: NewWindow(1000),
forwardWindow: 1000,
streams: make(map[StreamID]*Stream),
}
return circ
}
func HybridDecrypt(priv openssl.PrivateKey, d []byte) ([]byte, error) {
// XXX this could probably be optimized a little
res, err := priv.Decrypt(d[0:128])
if err != nil {
return nil, err
}
if len(res) < 86 {
return res, nil
}
data1 := res[16:86]
aes := aes.New(res[0:16], make([]byte, 16))
res2 := make([]byte, len(d)-128)
res2, err = aes.Crypt(d[128:len(d)], res2)
if err != nil {
return nil, err
}
finalRes := make([]byte, len(data1)+len(res2))
copy(finalRes, data1)
copy(finalRes[len(data1):], res2)
return finalRes, nil
}