Refactor ConvertBitsToBytes function

rarimo · Dec 30, 2024 · 9b65208 · 9b65208
1 parent a90a4f8
commit 9b65208
Showing 1 changed file with 8 additions and 6 deletions.
diff --git a/internal/utils/asn1_operations.go b/internal/utils/asn1_operations.go
@@ -19,17 +19,19 @@ import (
 
 func ConvertBitsToBytes(data []byte, numBits int) ([]byte, error) {
 	numBytes := (numBits + 7) / 8
-	if len(data) < numBytes {
-		return nil, fmt.Errorf("data is too short, requires at least %d bytes", numBytes)
+	result := make([]byte, numBytes)
+
+	startIndex := len(data) - numBytes
+	if startIndex < 0 {
+		startIndex = 0
 	}
 
-	result := make([]byte, numBytes)
-	copy(result, data[:numBytes])
+	copy(result[max(0, numBytes-len(data)):], data[startIndex:])
 
 	remainingBits := numBits % 8
 	if remainingBits != 0 {
-		mask := byte(0xFF << (8 - remainingBits))
-		result[numBytes-1] &= mask
+		mask := byte(0xFF >> (8 - remainingBits))
+		result[0] &= mask
 	}
 
 	return result, nil