From 48cc045e80c30d18300410f6407fa255a3ea25ac Mon Sep 17 00:00:00 2001
From: filifa <filifa.breath652@8alias.com>
Date: Wed, 10 Sep 2025 20:50:11 -0400
Subject: [PATCH] return error if no solution found

---
 cmd/discreteLog.go | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/cmd/discreteLog.go b/cmd/discreteLog.go
index 8a1f98d..f025a86 100644
--- a/cmd/discreteLog.go
+++ b/cmd/discreteLog.go
@@ -17,6 +17,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"math/big"
 
@@ -39,7 +40,7 @@ func ceilSqrt(x *big.Int) *big.Int {
 	return z
 }
 
-func babyStepGiantStep(n, g, x, order *big.Int) *big.Int {
+func babyStepGiantStep(n, g, x, order *big.Int) (*big.Int, error) {
 	var m *big.Int
 	if order == nil {
 		// m = ceil(sqrt(n - 1))
@@ -67,15 +68,14 @@ func babyStepGiantStep(n, g, x, order *big.Int) *big.Int {
 		if ok {
 			i.Mul(i, m)
 			i.Add(i, j)
-			return i
+			return i, nil
 		}
 
 		gamma.Mul(gamma, p)
 		gamma.Mod(gamma, n)
 	}
 
-	// TODO: return an error instead
-	return nil
+	return nil, errors.New("no solution")
 }
 
 func discreteLog(cmd *cobra.Command, args []string) {
@@ -102,7 +102,11 @@ func discreteLog(cmd *cobra.Command, args []string) {
 		}
 	}
 
-	k := babyStepGiantStep(n, g, x, order)
+	k, err := babyStepGiantStep(n, g, x, order)
+	if err != nil {
+		cobra.CheckErr(err)
+	}
+
 	fmt.Println(k)
 }