[add] 更新evilpot，修复大数计算bug，以及加法计算错误

Author: Jarcis-cy

tests/evilpot/evil/evil.go

@@ -7,15 +7,14 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"log"
+	"math/big"
 	"net/http"
 	"net/http/httputil"
 	"net/url"
 	"regexp"
 	"strconv"
 	"sync"
 	"time"
-
-	"github.com/dengsgo/math-engine/engine"
 )
 
 func ServeEvilServer(addr string, hard bool) error {
@@ -94,14 +93,19 @@ func NewEvilServeMux(hard bool) *http.ServeMux {
 				}
 			}
 		}
-
-		for _, expr := range mathRe.FindAllString(unescape, -1) {
-			r, err := engine.ParseAndExec(expr)
-			if err != nil {
-				log.Println(err)
-				continue
+		for _, match := range []string{string(data), unescape} {
+			for _, expr := range mathRe.FindAllString(match, -1) {
+				r, err := calculate(expr)
+				if err != nil {
+					r = big.NewFloat(0)
+				}
+				switch v := r.(type) {
+				case *big.Int:
+					GenEvilContent(buf, []byte(v.String()))
+				case *big.Float:
+					GenEvilContent(buf, []byte(v.Text('f', 10)))
+				}
 			}
-			GenEvilContent(buf, []byte(strconv.Itoa(int(r))))
 		}
 
 		_, _ = writer.Write(buf.Bytes())

tests/evilpot/evil/util.go

@@ -1,5 +1,12 @@
 package evil
 
+import (
+	"math/big"
+	"strconv"
+	"strings"
+	"unicode"
+)
+
 var SepFunc = func(b byte) bool {
 	if 48 <= b && b <= 57 {
 		return false
@@ -42,3 +49,191 @@ func Split(data []byte, sep func(b byte) bool, handler func([]byte) bool) {
 	}
 	return
 }
+
+func calculate(expression string) (interface{}, error) {
+	// 去除多余空格
+	expression = strings.TrimSpace(expression)
+	expression = strings.ReplaceAll(expression, " ", "")
+
+	// 定义运算符优先级
+	precedence := map[rune]int{
+		'+': 1,
+		'-': 1,
+		'*': 2,
+		'/': 2,
+	}
+
+	// 定义两个栈，一个存操作数，一个存操作符
+	var numStack []interface{}
+	var opStack []rune
+
+	// 辅助函数，用于执行整数计算
+	applyOpInt := func(op rune, b, a *big.Int) *big.Int {
+		result := new(big.Int)
+		switch op {
+		case '+':
+			return result.Add(a, b)
+		case '-':
+			return result.Sub(a, b)
+		case '*':
+			return result.Mul(a, b)
+		case '/':
+			return result.Div(a, b)
+		default:
+			return big.NewInt(0)
+		}
+	}
+
+	// 辅助函数，用于执行浮点数计算
+	applyOpFloat := func(op rune, b, a *big.Float) *big.Float {
+		result := new(big.Float)
+		switch op {
+		case '+':
+			return result.Add(a, b)
+		case '-':
+			return result.Sub(a, b)
+		case '*':
+			return result.Mul(a, b)
+		case '/':
+			return result.Quo(a, b)
+		default:
+			return big.NewFloat(0)
+		}
+	}
+
+	// 判断字符串是否为整数
+	isInteger := func(s string) bool {
+		_, err := strconv.ParseInt(s, 10, 64)
+		return err == nil
+	}
+
+	// 将操作数转换为浮点数
+	toBigFloat := func(num interface{}) *big.Float {
+		switch v := num.(type) {
+		case *big.Int:
+			return new(big.Float).SetInt(v)
+		case *big.Float:
+			return v
+		default:
+			return big.NewFloat(0)
+		}
+	}
+
+	// 解析表达式并进行计算
+	i := 0
+	for i < len(expression) {
+		char := rune(expression[i])
+
+		if unicode.IsDigit(char) || char == '.' {
+			// 处理数字和小数点
+			j := i
+			for j < len(expression) && (unicode.IsDigit(rune(expression[j])) || rune(expression[j]) == '.') {
+				j++
+			}
+			numStr := expression[i:j]
+			if isInteger(numStr) {
+				num := new(big.Int)
+				num, ok := num.SetString(numStr, 10)
+				if !ok {
+					return big.NewFloat(0), nil
+				}
+				numStack = append(numStack, num)
+			} else {
+				num, ok := new(big.Float).SetString(numStr)
+				if !ok {
+					return big.NewFloat(0), nil
+				}
+				numStack = append(numStack, num)
+			}
+			i = j
+		} else if char == '(' {
+			// 处理左括号
+			opStack = append(opStack, char)
+			i++
+		} else if char == ')' {
+			// 处理右括号
+			for len(opStack) > 0 && opStack[len(opStack)-1] != '(' {
+				op := opStack[len(opStack)-1]
+				opStack = opStack[:len(opStack)-1]
+				b := numStack[len(numStack)-1]
+				numStack = numStack[:len(numStack)-1]
+				a := numStack[len(numStack)-1]
+				numStack = numStack[:len(numStack)-1]
+
+				if aInt, okA := a.(*big.Int); okA {
+					if bInt, okB := b.(*big.Int); okB {
+						result := applyOpInt(op, bInt, aInt)
+						numStack = append(numStack, result)
+					} else {
+						result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+						numStack = append(numStack, result)
+					}
+				} else {
+					result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+					numStack = append(numStack, result)
+				}
+			}
+			// 移除左括号
+			if len(opStack) > 0 {
+				opStack = opStack[:len(opStack)-1]
+			}
+			i++
+		} else if strings.ContainsRune("+-*/", char) {
+			// 处理运算符
+			for len(opStack) > 0 && precedence[char] <= precedence[opStack[len(opStack)-1]] {
+				op := opStack[len(opStack)-1]
+				opStack = opStack[:len(opStack)-1]
+				b := numStack[len(numStack)-1]
+				numStack = numStack[:len(numStack)-1]
+				a := numStack[len(numStack)-1]
+				numStack = numStack[:len(numStack)-1]
+
+				if aInt, okA := a.(*big.Int); okA {
+					if bInt, okB := b.(*big.Int); okB {
+						result := applyOpInt(op, bInt, aInt)
+						numStack = append(numStack, result)
+					} else {
+						result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+						numStack = append(numStack, result)
+					}
+				} else {
+					result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+					numStack = append(numStack, result)
+				}
+			}
+			opStack = append(opStack, char)
+			i++
+		} else {
+			return big.NewFloat(0), nil
+		}
+	}
+
+	// 处理剩余的运算符
+	for len(opStack) > 0 {
+		op := opStack[len(opStack)-1]
+		opStack = opStack[:len(opStack)-1]
+		b := numStack[len(numStack)-1]
+		numStack = numStack[:len(numStack)-1]
+		a := numStack[len(numStack)-1]
+		numStack = numStack[:len(numStack)-1]
+
+		if aInt, okA := a.(*big.Int); okA {
+			if bInt, okB := b.(*big.Int); okB {
+				result := applyOpInt(op, bInt, aInt)
+				numStack = append(numStack, result)
+			} else {
+				result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+				numStack = append(numStack, result)
+			}
+		} else {
+			result := applyOpFloat(op, toBigFloat(b), toBigFloat(a))
+			numStack = append(numStack, result)
+		}
+	}
+
+	if len(numStack) != 1 {
+		return big.NewFloat(0), nil
+	}
+
+	return numStack[0], nil
+}