63 lines
1.9 KiB
Go
63 lines
1.9 KiB
Go
package confirm
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import (
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"fmt"
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"github.com/indra-labs/indra"
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"github.com/indra-labs/indra/pkg/crypto/nonce"
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log2 "github.com/indra-labs/indra/pkg/proc/log"
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"github.com/indra-labs/indra/pkg/types"
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"github.com/indra-labs/indra/pkg/util/slice"
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"github.com/indra-labs/indra/pkg/wire/magicbytes"
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)
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const (
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MagicString = "cn"
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Len = magicbytes.Len + nonce.IDLen
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)
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var (
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log = log2.GetLogger(indra.PathBase)
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check = log.E.Chk
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Magic = slice.Bytes(MagicString)
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_ types.Onion = &OnionSkin{}
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)
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// OnionSkin confirmation is an encryption layer for messages returned to the
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// client on the inside of an onion, for Ping and Ciphers messages, providing a
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// confirmation of the transit of the onion through its encoded route.
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//
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// It is encrypted because otherwise internal identifiers could be leaked and
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// potentially reveal something about the entropy of a client/relay.
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//
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// In order to speed up recognition, the key of the table of pending Ping and
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// Ciphers messages will include the last hop that will deliver this layer of
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// the onion - there can be more than one up in the air at a time, but they are
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// randomly selected, so they will generally be a much smaller subset versus the
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// current full set of Session s currently open.
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type OnionSkin struct {
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nonce.ID
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}
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func (x *OnionSkin) String() string {
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return fmt.Sprintf("\n\tnonce: %x\n",
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x.ID)
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}
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func (x *OnionSkin) Inner() types.Onion { return nil }
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func (x *OnionSkin) Insert(o types.Onion) {}
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func (x *OnionSkin) Len() int { return Len }
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func (x *OnionSkin) Encode(b slice.Bytes, c *slice.Cursor) {
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copy(b[*c:c.Inc(magicbytes.Len)], Magic)
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// Copy in the ID.
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copy(b[*c:c.Inc(nonce.IDLen)], x.ID[:])
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}
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func (x *OnionSkin) Decode(b slice.Bytes, c *slice.Cursor) (e error) {
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if len(b[*c:]) < Len-magicbytes.Len {
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return magicbytes.TooShort(len(b[*c:]),
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Len-magicbytes.Len, string(Magic))
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}
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copy(x.ID[:], b[*c:c.Inc(nonce.IDLen)])
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return
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}
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