Switch to base64 encoding for fiat onramp messaging memo value (#84)

Author: jeffyanta

pkg/code/thirdparty/message.go

@@ -3,6 +3,7 @@ package thirdparty
 import (
 	"crypto/ed25519"
 	"crypto/rand"
+	"encoding/base64"
 	"encoding/binary"
 	"strings"
 	"time"
@@ -299,14 +300,14 @@ func (m *FiatOnrampPurchaseMessage) Encode() ([]byte, error) {
 	buffer = append(buffer, m.Nonce[:]...)
 
 	// Because memo requires UTF-8, and this is more space efficient than base64
-	return base122.Encode(buffer)
+	return []byte(base64.StdEncoding.EncodeToString(buffer)), nil
 }
 
 // DecodeFiatOnrampPurchaseMessage attempts to decode a byte payload into a FiatOnrampPurchaseMessage
 func DecodeFiatOnrampPurchaseMessage(payload []byte) (*FiatOnrampPurchaseMessage, error) {
 	errInvalidPayload := errors.New("invalid payload")
 
-	buffer, err := base122.Decode(payload)
+	buffer, err := base64.StdEncoding.DecodeString(string(payload))
 	if err != nil {
 		return nil, errors.Wrap(err, errInvalidPayload.Error())
 	}

pkg/code/thirdparty/message_test.go

@@ -73,3 +73,16 @@ func TestFiatOnrampPurchaseMessage_RoundTrip(t *testing.T) {
 	assert.Equal(t, blockchainMessage.Flags, decodedBlockchainMessage.Flags)
 	assert.Equal(t, blockchainMessage.Nonce, decodedBlockchainMessage.Nonce)
 }
+
+func TestFiatOnrampPurchase_CrossPlatform(t *testing.T) {
+	nonce, err := uuid.Parse("c24a3bf2-ad4f-4756-944e-81948ff10882")
+	require.NoError(t, err)
+
+	msg, err := NewFiatOnrampPurchaseMessage(nonce)
+	require.NoError(t, err)
+
+	expected := "AQAAAAAAwko78q1PR1aUToGUj/EIgg=="
+	actual, err := msg.Encode()
+	require.NoError(t, err)
+	assert.Equal(t, expected, string(actual))
+}