Change how the signer data is copied from horizon to txnbuild

Author: leighmcculloch

protocols/horizon/main.go

@@ -128,6 +128,15 @@ func (a *Account) GetData(key string) ([]byte, error) {
 	return base64.StdEncoding.DecodeString(a.Data[key])
 }
 
+// SignerSummary returns a map of signer's keys to weights.
+func (a *Account) SignerSummary() map[string]int32 {
+	m := map[string]int32{}
+	for _, s := range a.Signers {
+		m[s.Key] = s.Weight
+	}
+	return m
+}
+
 // AccountSigner is the account signer information.
 type AccountSigner struct {
 	Links struct {

txnbuild/transaction.go

@@ -492,6 +492,9 @@ func ReadChallengeTx(challengeTx, serverAccountID, network string) (tx Transacti
 	return tx, clientAccountID, nil
 }
 
+// SignerSummary is a map of signers to their weights.
+type SignerSummary map[string]int32
+
 // VerifyChallengeTxThreshold verifies that for a SEP 10 challenge transaction
 // all signatures on the transaction are accounted for and that the signatures
 // meet a threshold on an account. A transaction is verified if it is signed by
@@ -505,33 +508,26 @@ func ReadChallengeTx(challengeTx, serverAccountID, network string) (tx Transacti
 //  - One or more signatures in the transaction are not identifiable as the
 //    server account or one of the signers provided in the arguments.
 //  - The signatures are all valid but do not meet the threshold.
-func VerifyChallengeTxThreshold(challengeTx, serverAccountID, network string, threshold Threshold, signers []Signer) (signersFound []Signer, err error) {
-	signerMap := map[string]Signer{}
-	signerAddresses := make([]string, 0, len(signers))
-	for _, s := range signers {
-		signerMap[s.Address] = s
-		signerAddresses = append(signerAddresses, s.Address)
+func VerifyChallengeTxThreshold(challengeTx, serverAccountID, network string, threshold Threshold, signerSummary SignerSummary) (signersFound []string, err error) {
+	signerAddresses := make([]string, 0, len(signerSummary))
+	for s := range signerSummary {
+		signerAddresses = append(signerAddresses, s)
 	}
 
-	signerAddressesFound, err := VerifyChallengeTxSigners(challengeTx, serverAccountID, network, signerAddresses...)
+	signersFound, err = VerifyChallengeTxSigners(challengeTx, serverAccountID, network, signerAddresses...)
 	if err != nil {
 		return nil, err
 	}
 
 	weight := Threshold(0)
-	for _, s := range signerAddressesFound {
-		weight += signerMap[s].Weight
+	for _, s := range signersFound {
+		weight += Threshold(signerSummary[s])
 	}
 
 	if weight < threshold {
 		return nil, errors.Errorf("signers with weight %d do not meet threshold %d", weight, threshold)
 	}
 
-	signersFound = make([]Signer, 0, len(signerAddressesFound))
-	for _, s := range signerAddressesFound {
-		signersFound = append(signersFound, signerMap[s])
-	}
-
 	return signersFound, nil
 }
 

txnbuild/transaction_challenge_example_test.go

@@ -92,26 +92,20 @@ func ExampleVerifyChallengeTxThreshold() {
 
 		if clientAccountExists {
 			// Server gets list of signers from account
-			signers := make([]txnbuild.Signer, 0, len(horizonClientAccount.Signers))
-			for _, hs := range horizonClientAccount.Signers {
-				signers = append(signers, txnbuild.Signer{
-					Address: hs.Key,
-					Weight:  txnbuild.Threshold(hs.Weight),
-				})
-			}
+			signerSummary := horizonClientAccount.SignerSummary()
 
 			// Server chooses the threshold to require: low, med or high
 			threshold := txnbuild.Threshold(horizonClientAccount.Thresholds.MedThreshold)
 
 			// Server verifies threshold is met
-			signersFound, err := txnbuild.VerifyChallengeTxThreshold(signedChallengeTx, serverAccount.Address(), network.TestNetworkPassphrase, threshold, signers)
+			signers, err := txnbuild.VerifyChallengeTxThreshold(signedChallengeTx, serverAccount.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
 			if err != nil {
 				fmt.Println("Error:", err)
 				return
 			}
 			fmt.Println("Client Signers Verified:")
-			for _, signerFound := range signersFound {
-				fmt.Println(signerFound.Address, "weight:", signerFound.Weight)
+			for _, signer := range signers {
+				fmt.Println(signer, "weight:", signerSummary[signer])
 			}
 		} else {
 			// Server verifies that master key has signed challenge transaction

txnbuild/transaction_test.go

@@ -1584,8 +1584,11 @@ func TestVerifyChallengeTxThreshold_validServerAndClientKeyMeetingThreshold(t *t
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(1)
-	signers := []Signer{
-		{Address: clientKP.Address(), Weight: 1},
+	signerSummary := SignerSummary{
+		clientKP.Address(): 1,
+	}
+	wantSigners := []string{
+		clientKP.Address(),
 	}
 
 	err := tx.Build()
@@ -1594,8 +1597,8 @@ func TestVerifyChallengeTxThreshold_validServerAndClientKeyMeetingThreshold(t *t
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
-	assert.Equal(t, signers, signersFound)
+	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
+	assert.Equal(t, wantSigners, signersFound)
 	assert.NoError(t, err)
 }
 
@@ -1617,9 +1620,13 @@ func TestVerifyChallengeTxThreshold_validServerAndMultipleClientKeyMeetingThresh
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(3)
-	signers := []Signer{
-		{Address: clientKP1.Address(), Weight: 1},
-		{Address: clientKP2.Address(), Weight: 2},
+	signerSummary := map[string]int32{
+		clientKP1.Address(): 1,
+		clientKP2.Address(): 2,
+	}
+	wantSigners := []string{
+		clientKP1.Address(),
+		clientKP2.Address(),
 	}
 
 	err := tx.Build()
@@ -1628,8 +1635,8 @@ func TestVerifyChallengeTxThreshold_validServerAndMultipleClientKeyMeetingThresh
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
-	assert.Equal(t, signers, signersFound)
+	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
+	assert.Equal(t, wantSigners, signersFound)
 	assert.NoError(t, err)
 }
 
@@ -1652,10 +1659,14 @@ func TestVerifyChallengeTxThreshold_validServerAndMultipleClientKeyMeetingThresh
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(3)
-	signers := []Signer{
-		{Address: clientKP1.Address(), Weight: 1},
-		{Address: clientKP2.Address(), Weight: 2},
-		{Address: clientKP3.Address(), Weight: 2},
+	signerSummary := SignerSummary{
+		clientKP1.Address(): 1,
+		clientKP2.Address(): 2,
+		clientKP3.Address(): 2,
+	}
+	wantSigners := []string{
+		clientKP1.Address(),
+		clientKP2.Address(),
 	}
 
 	err := tx.Build()
@@ -1664,12 +1675,8 @@ func TestVerifyChallengeTxThreshold_validServerAndMultipleClientKeyMeetingThresh
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
-	wantSignersFound := []Signer{
-		{Address: clientKP1.Address(), Weight: 1},
-		{Address: clientKP2.Address(), Weight: 2},
-	}
-	assert.Equal(t, wantSignersFound, signersFound)
+	signersFound, err := VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
+	assert.Equal(t, wantSigners, signersFound)
 	assert.NoError(t, err)
 }
 
@@ -1692,10 +1699,10 @@ func TestVerifyChallengeTxThreshold_invalidServerAndMultipleClientKeyNotMeetingT
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(10)
-	signers := []Signer{
-		{Address: clientKP1.Address(), Weight: 1},
-		{Address: clientKP2.Address(), Weight: 2},
-		{Address: clientKP3.Address(), Weight: 2},
+	signerSummary := SignerSummary{
+		clientKP1.Address(): 1,
+		clientKP2.Address(): 2,
+		clientKP3.Address(): 2,
 	}
 
 	err := tx.Build()
@@ -1704,7 +1711,7 @@ func TestVerifyChallengeTxThreshold_invalidServerAndMultipleClientKeyNotMeetingT
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
+	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
 	assert.EqualError(t, err, "signers with weight 3 do not meet threshold 10")
 }
 
@@ -1727,9 +1734,9 @@ func TestVerifyChallengeTxThreshold_invalidClientKeyUnrecognized(t *testing.T) {
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(10)
-	signers := []Signer{
-		{Address: clientKP1.Address(), Weight: 1},
-		{Address: clientKP2.Address(), Weight: 2},
+	signerSummary := map[string]int32{
+		clientKP1.Address(): 1,
+		clientKP2.Address(): 2,
 	}
 
 	err := tx.Build()
@@ -1738,7 +1745,7 @@ func TestVerifyChallengeTxThreshold_invalidClientKeyUnrecognized(t *testing.T) {
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
+	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
 	assert.EqualError(t, err, "transaction has unrecognized signatures")
 }
 
@@ -1761,15 +1768,15 @@ func TestVerifyChallengeTxThreshold_invalidNoSigners(t *testing.T) {
 		Network:       network.TestNetworkPassphrase,
 	}
 	threshold := Threshold(10)
-	signers := []Signer{}
+	signerSummary := SignerSummary{}
 
 	err := tx.Build()
 	require.NoError(t, err)
 	err = tx.Sign(serverKP, clientKP1, clientKP2, clientKP3)
 	assert.NoError(t, err)
 	tx64, err := tx.Base64()
 	require.NoError(t, err)
-	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signers)
+	_, err = VerifyChallengeTxThreshold(tx64, serverKP.Address(), network.TestNetworkPassphrase, threshold, signerSummary)
 	assert.EqualError(t, err, "no signers provided")
 }