move more precan stuff into precan.go

api/precan.go

@@ -11,11 +11,15 @@ import (
 	"encoding/binary"
 	"math/rand"
 
+	"github.com/cloudflare/circl/dh/sidh"
 	jww "github.com/spf13/jwalterweatherman"
+	"gitlab.com/elixxir/client/e2e/ratchet/partner/session"
 	"gitlab.com/elixxir/client/storage"
 	"gitlab.com/elixxir/client/storage/user"
+	"gitlab.com/elixxir/crypto/contact"
 	"gitlab.com/elixxir/crypto/cyclic"
 	"gitlab.com/elixxir/crypto/fastRNG"
+	"gitlab.com/elixxir/primitives/fact"
 	"gitlab.com/xx_network/crypto/csprng"
 	"gitlab.com/xx_network/crypto/signature/rsa"
 	"gitlab.com/xx_network/primitives/id"
@@ -94,3 +98,63 @@ func NewPrecannedClient(precannedID uint, defJSON, storageDir string,
 
 	return nil
 }
+
+// Create an insecure e2e relationship with a precanned user
+func (c *Client) MakePrecannedAuthenticatedChannel(precannedID uint) (
+	contact.Contact, error) {
+
+	precan := c.MakePrecannedContact(precannedID)
+
+	myID := binary.BigEndian.Uint64(c.GetUser().GetContact().ID[:])
+	// Pick a variant based on if their ID is bigger than mine.
+	myVariant := sidh.KeyVariantSidhA
+	theirVariant := sidh.KeyVariant(sidh.KeyVariantSidhB)
+	if myID > uint64(precannedID) {
+		myVariant = sidh.KeyVariantSidhB
+		theirVariant = sidh.KeyVariantSidhA
+	}
+	prng1 := rand.New(rand.NewSource(int64(precannedID)))
+	theirSIDHPrivKey := util.NewSIDHPrivateKey(theirVariant)
+	theirSIDHPubKey := util.NewSIDHPublicKey(theirVariant)
+	theirSIDHPrivKey.Generate(prng1)
+	theirSIDHPrivKey.GeneratePublicKey(theirSIDHPubKey)
+
+	prng2 := rand.New(rand.NewSource(int64(myID)))
+	mySIDHPrivKey := util.NewSIDHPrivateKey(myVariant)
+	mySIDHPubKey := util.NewSIDHPublicKey(myVariant)
+	mySIDHPrivKey.Generate(prng2)
+	mySIDHPrivKey.GeneratePublicKey(mySIDHPubKey)
+
+	// add the precanned user as a e2e contact
+	// FIXME: these params need to be threaded through...
+	sesParam := session.GetDefaultParams()
+	_, err := c.e2e.AddPartner(precan.ID, precan.DhPubKey,
+		c.e2e.GetHistoricalDHPrivkey(), theirSIDHPubKey,
+		mySIDHPrivKey, sesParam, sesParam)
+
+	// check garbled messages in case any messages arrived before creating
+	// the channel
+	c.network.CheckInProgressMessages()
+
+	return precan, err
+}
+
+// Create an insecure e2e contact object for a precanned user
+func (c *Client) MakePrecannedContact(precannedID uint) contact.Contact {
+
+	e2eGrp := c.storage.GetE2EGroup()
+
+	precanned := createPrecannedUser(precannedID, c.rng.GetStream(),
+		c.storage.GetCmixGroup(), e2eGrp)
+
+	// compute their public e2e key
+	partnerPubKey := e2eGrp.ExpG(precanned.E2eDhPrivateKey,
+		e2eGrp.NewInt(1))
+
+	return contact.Contact{
+		ID:             precanned.ReceptionID,
+		DhPubKey:       partnerPubKey,
+		OwnershipProof: nil,
+		Facts:          make([]fact.Fact, 0),
+	}
+}