libxc: Coinbase API fixes (#3570)

Author: martonp

client/mm/libxc/coinbase.go

@@ -1513,11 +1513,11 @@ var max = big.NewInt(math.MaxInt64)
 type nonceSource struct{}
 
 func (n nonceSource) Nonce() (string, error) {
-	r, err := rand.Int(rand.Reader, max)
-	if err != nil {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
 		return "", err
 	}
-	return r.String(), nil
+	return hex.EncodeToString(b), nil
 }
 
 type APIKeyClaims struct {
@@ -1537,7 +1537,7 @@ func buildJWT(apiName, uri string, privKey *ecdsa.PrivateKey) (string, error) {
 	cl := &APIKeyClaims{
 		Claims: &jwt.Claims{
 			Subject:   apiName,
-			Issuer:    "coinbase-cloud",
+			Issuer:    "cdp",
 			NotBefore: jwt.NewNumericDate(time.Now()),
 			Expiry:    jwt.NewNumericDate(time.Now().Add(time.Minute * 2)),
 		},

client/mm/libxc/coinbase_live_test.go

@@ -571,7 +571,13 @@ func TestPlaceTrade(t *testing.T) {
 	}
 
 	msgRate := calc.MessageRate(rate, bui, qui)
-	qty := uint64(math.Round(amount * float64(bui.Conventional.ConversionFactor)))
+
+	var qty, quoteQty uint64
+	if !sell && orderType == OrderTypeMarket {
+		quoteQty = uint64(math.Round(amount * float64(qui.Conventional.ConversionFactor)))
+	} else {
+		qty = uint64(math.Round(amount * float64(bui.Conventional.ConversionFactor)))
+	}
 
 	wg := sync.WaitGroup{}
 	wg.Add(1)
@@ -597,7 +603,7 @@ func TestPlaceTrade(t *testing.T) {
 		}
 	}()
 
-	trade, err := c.Trade(ctx, uint32(baseID), uint32(quoteID), sell, msgRate, qty, orderType, updaterID)
+	trade, err := c.Trade(ctx, uint32(baseID), uint32(quoteID), sell, msgRate, qty, quoteQty, orderType, updaterID)
 	if err != nil {
 		t.Fatalf("Trade error: %v", err)
 	}