mirror of
https://github.com/saymrwulf/swisspost-evoting-go-poc.git
synced 2026-09-04 20:23:55 +00:00
saymrwulf
127ae61d11
The return code the voter checks is now genuinely computed by the CCs from the submitted ciphertext, not looked up from the card: - returncode_extract.go: after a ballot is accepted, the server asks each CC to exponentiate E2 by its return-code key (product over CCs = Enc(vote^Σk)), then each CC contributes a partial-decryption factor; the server recovers vote^Σk, which equals the card base prime_sel^Σk, and looks up the short code. - The server returns that code to the voter, who checks it against the card for the chosen option; a mismatch aborts with a clear error. Soundness test: a malicious client that encrypts option A for the tally (E1) but option B in the return-code channel (E2) is REJECTED by the plaintext-equality proof — so the code shown always reflects the tallied vote. This closes the cast-as-intended gap (the old return codes were decorative, finding F16). Card lCC now uses a fixed tau so extraction can recompute it without learning the option up front. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
59 lines
1.7 KiB
Go
59 lines
1.7 KiB
Go
package party
|
|
|
|
import (
|
|
"fmt"
|
|
|
|
"github.com/user/evote/pkg/transport"
|
|
)
|
|
|
|
// Phase message handlers. These are filled in incrementally (setup, then
|
|
// voting, then tally). Until a phase is implemented its handler rejects unknown
|
|
// message types cleanly rather than panicking — the transport boundary must
|
|
// never crash on an unexpected message.
|
|
|
|
func (p *SetupComponent) handleSetupMsg(env *transport.Envelope) (*transport.Envelope, error) {
|
|
return nil, fmt.Errorf("%s: unhandled message type %q", p.id.Name, env.Type)
|
|
}
|
|
|
|
func (p *ControlComponent) handleCCMsg(env *transport.Envelope) (*transport.Envelope, error) {
|
|
switch env.Type {
|
|
case MsgGenCCKeys:
|
|
return p.handleGenCCKeys(env)
|
|
case MsgLongCodeShareReq:
|
|
return p.handleLongCodeShare(env)
|
|
case MsgVerifyBallot:
|
|
return p.handleVerifyBallot(env)
|
|
case MsgShuffle:
|
|
return p.handleShuffle(env)
|
|
case MsgRCExpReq:
|
|
return p.handleRCExp(env)
|
|
case MsgRCDecReq:
|
|
return p.handleRCDec(env)
|
|
default:
|
|
return nil, fmt.Errorf("%s: unhandled message type %q", p.id.Name, env.Type)
|
|
}
|
|
}
|
|
|
|
func (p *ElectoralBoard) handleEBMsg(env *transport.Envelope) (*transport.Envelope, error) {
|
|
switch env.Type {
|
|
case MsgGenEBKey:
|
|
return p.handleGenEBKey(env)
|
|
case MsgFinalMix:
|
|
return p.handleFinalMix(env)
|
|
default:
|
|
return nil, fmt.Errorf("%s: unhandled message type %q", p.id.Name, env.Type)
|
|
}
|
|
}
|
|
|
|
func (p *VotingServer) handleServerMsg(env *transport.Envelope) (*transport.Envelope, error) {
|
|
switch env.Type {
|
|
case MsgMappingTable:
|
|
return p.handleMappingTable(env)
|
|
case MsgCastBallot:
|
|
return p.handleCastBallot(env)
|
|
case MsgStartTally:
|
|
return p.handleStartTally(env)
|
|
default:
|
|
return nil, fmt.Errorf("%s: unhandled message type %q", p.id.Name, env.Type)
|
|
}
|
|
}
|