diff --git a/api/authenticatedChannel.go b/api/authenticatedChannel.go
index 88682af983c107345b6415648bec9558f2eb4d6b..24b5a8e4af3c771d59dabc3e01d6ffa1b8125a17 100644
--- a/api/authenticatedChannel.go
+++ b/api/authenticatedChannel.go
@@ -125,3 +125,17 @@ func (c *Client) MakePrecannedContact(precannedID uint) contact.Contact {
Facts: make([]fact.Fact, 0),
}
}
+
+// GetRelationshipFingerprint returns a unique 15 character fingerprint for an
+// E2E relationship. An error is returned if no relationship with the partner
+// is found.
+func (c *Client) GetRelationshipFingerprint(partner *id.ID) (string, error) {
+ m, err := c.storage.E2e().GetPartner(partner)
+ if err != nil {
+ return "", errors.Errorf("could not get partner %s: %+v", partner, err)
+ } else if m == nil {
+ return "", errors.Errorf("manager for partner %s is nil.", partner)
+ }
+
+ return m.GetRelationshipFingerprint(), nil
+}
diff --git a/bindings/authenticatedChannels.go b/bindings/authenticatedChannels.go
index 30b12f0a1b3039fba5b18eafeff874cc7a438a60..da1d0d7ea128c15a6e4d407f8a7a88430666fd16 100644
--- a/bindings/authenticatedChannels.go
+++ b/bindings/authenticatedChannels.go
@@ -11,6 +11,7 @@ import (
"errors"
"fmt"
"gitlab.com/elixxir/crypto/contact"
+ "gitlab.com/xx_network/primitives/id"
)
// Create an insecure e2e relationship with a precanned user
@@ -123,3 +124,15 @@ func (c *Client) VerifyOwnership(receivedMarshaled, verifiedMarshaled []byte) (b
return c.api.VerifyOwnership(received, verified), nil
}
+
+// GetRelationshipFingerprint returns a unique 15 character fingerprint for an
+// E2E relationship. An error is returned if no relationship with the partner
+// is found.
+func (c *Client) GetRelationshipFingerprint(partnerID []byte) (string, error) {
+ partner, err := id.Unmarshal(partnerID)
+ if err != nil {
+ return "", err
+ }
+
+ return c.api.GetRelationshipFingerprint(partner)
+}
diff --git a/storage/e2e/manager.go b/storage/e2e/manager.go
index 802e81ebe2329f5bd3714500e0229071eaea3bd3..6d7691b2b8f402c92ea6d4615a175b0b14b4b61e 100644
--- a/storage/e2e/manager.go
+++ b/storage/e2e/manager.go
@@ -8,6 +8,8 @@
package e2e
import (
+ "bytes"
+ "encoding/base64"
"fmt"
"github.com/pkg/errors"
jww "github.com/spf13/jwalterweatherman"
@@ -17,6 +19,8 @@ import (
"gitlab.com/elixxir/crypto/cyclic"
dh "gitlab.com/elixxir/crypto/diffieHellman"
"gitlab.com/xx_network/primitives/id"
+ "golang.org/x/crypto/blake2b"
+ "sort"
)
const managerPrefix = "Manager{partner:%s}"
@@ -198,3 +202,24 @@ func (m *Manager) GetMyOriginPrivateKey() *cyclic.Int {
func (m *Manager) GetPartnerOriginPublicKey() *cyclic.Int {
return m.originPartnerPubKey.DeepCopy()
}
+
+const relationshipFpLength = 15
+
+// GetRelationshipFingerprint returns a unique fingerprint for an E2E
+// relationship. The fingerprint is a base 64 encoded hash of of the two
+// relationship fingerprints truncated to 15 characters.
+func (m *Manager) GetRelationshipFingerprint() string {
+ // Sort fingerprints
+ fps := [][]byte{m.receive.fingerprint, m.send.fingerprint}
+ less := func(i, j int) bool { return bytes.Compare(fps[i], fps[j]) == -1 }
+ sort.Slice(fps, less)
+
+ // Hash fingerprints
+ h, _ := blake2b.New256(nil)
+ for _, fp := range fps {
+ h.Write(fp)
+ }
+
+ // Base 64 encode hash and truncate
+ return base64.StdEncoding.EncodeToString(h.Sum(nil))[:relationshipFpLength]
+}
diff --git a/storage/e2e/manager_test.go b/storage/e2e/manager_test.go
index 907bbff91b561d2267b71371356ae7bf6f332b86..195b0752a603002dcb395507fc0b7d361a0b235a 100644
--- a/storage/e2e/manager_test.go
+++ b/storage/e2e/manager_test.go
@@ -9,12 +9,14 @@ package e2e
import (
"bytes"
+ "encoding/base64"
"fmt"
"gitlab.com/elixxir/client/interfaces/params"
"gitlab.com/elixxir/client/storage/versioned"
"gitlab.com/elixxir/ekv"
"gitlab.com/xx_network/primitives/id"
"gitlab.com/xx_network/primitives/netTime"
+ "golang.org/x/crypto/blake2b"
"math/rand"
"reflect"
"testing"
@@ -283,3 +285,65 @@ func managersEqual(expected, received *Manager, t *testing.T) bool {
return equal
}
+
+// Unit test of Manager.GetRelationshipFingerprint.
+func TestManager_GetRelationshipFingerprint(t *testing.T) {
+ m, _ := newTestManager(t)
+ m.receive.fingerprint = []byte{5}
+ m.send.fingerprint = []byte{10}
+ h, _ := blake2b.New256(nil)
+ h.Write(append(m.receive.fingerprint, m.send.fingerprint...))
+ expected := base64.StdEncoding.EncodeToString(h.Sum(nil))[:relationshipFpLength]
+
+ fp := m.GetRelationshipFingerprint()
+ if fp != expected {
+ t.Errorf("GetRelationshipFingerprint did not return the expected "+
+ "fingerprint.\nexpected: %s\nreceived: %s", expected, fp)
+ }
+
+ // Flip the order and show that the output is the same.
+ m.receive.fingerprint, m.send.fingerprint = m.send.fingerprint, m.receive.fingerprint
+
+ fp = m.GetRelationshipFingerprint()
+ if fp != expected {
+ t.Errorf("GetRelationshipFingerprint did not return the expected "+
+ "fingerprint.\nexpected: %s\nreceived: %s", expected, fp)
+ }
+}
+
+// Tests the consistency of the output of Manager.GetRelationshipFingerprint.
+func TestManager_GetRelationshipFingerprint_Consistency(t *testing.T) {
+ m, _ := newTestManager(t)
+ prng := rand.New(rand.NewSource(42))
+ expectedFps := []string{
+ "GmeTCfxGOqRqeID", "gbpJjHd3tIe8BKy", "2/ZdG+WNzODJBiF",
+ "+V1ySeDLQfQNSkv", "23OMC+rBmCk+gsu", "qHu5MUVs83oMqy8",
+ "kuXqxsezI0kS9Bc", "SlEhsoZ4BzAMTtr", "yG8m6SPQfV/sbTR",
+ "j01ZSSm762TH7mj", "SKFDbFvsPcohKPw", "6JB5HK8DHGwS4uX",
+ "dU3mS1ujduGD+VY", "BDXAy3trbs8P4mu", "I4HoXW45EwWR0oD",
+ "661YH2l2jfOkHbA", "cSS9ZyTOQKVx67a", "ojfubzDIsMNYc/t",
+ "2WrEw83Yz6Rhq9I", "TQILxBIUWMiQS2j", "rEqdieDTXJfCQ6I",
+ }
+
+ for i, expected := range expectedFps {
+ prng.Read(m.receive.fingerprint)
+ prng.Read(m.send.fingerprint)
+
+ fp := m.GetRelationshipFingerprint()
+ if fp != expected {
+ t.Errorf("GetRelationshipFingerprint did not return the expected "+
+ "fingerprint (%d).\nexpected: %s\nreceived: %s", i, expected, fp)
+ }
+
+ // Flip the order and show that the output is the same.
+ m.receive.fingerprint, m.send.fingerprint = m.send.fingerprint, m.receive.fingerprint
+
+ fp = m.GetRelationshipFingerprint()
+ if fp != expected {
+ t.Errorf("GetRelationshipFingerprint did not return the expected "+
+ "fingerprint (%d).\nexpected: %s\nreceived: %s", i, expected, fp)
+ }
+
+ // fmt.Printf("\"%s\",\n", fp) // Uncomment to reprint expected values
+ }
+}