wings.patch

diff --git a/router/router.go b/router/router.go
index 52806a1..553d8cc 100644
--- a/router/router.go
+++ b/router/router.go
@@ -88,6 +88,7 @@ func Configure(m *wserver.Manager, client remote.Client) *gin.Engine {
 		files := server.Group("/files")
 		{
 			files.GET("/contents", getServerFileContents)
+			files.GET("/fingerprints", getServerFileFingerprints)
 			files.GET("/list-directory", getServerListDirectory)
 			files.PUT("/rename", putServerRenameFiles)
 			files.POST("/copy", postServerCopyFile)
diff --git a/router/router_server_files.go b/router/router_server_files.go
index 09ad8cd..ccb0e8c 100644
--- a/router/router_server_files.go
+++ b/router/router_server_files.go
@@ -2,7 +2,10 @@ package router
 
 import (
 	"bufio"
+	"bytes"
 	"context"
+	"crypto/sha512"
+	"encoding/hex"
 	"io"
 	"mime/multipart"
 	"net/http"
@@ -12,6 +15,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"sync"
 
 	"emperror.dev/errors"
 	"github.com/apex/log"
@@ -74,6 +78,70 @@ func getServerFileContents(c *gin.Context) {
 	}
 }
 
+// getServerFileFingerprints returns the fingerprints of some files on the server.
+func getServerFileFingerprints(c *gin.Context) {
+	s := middleware.ExtractServer(c)
+	paths := c.QueryArray("files")
+	algorithm := c.Query("algorithm")
+
+	if algorithm != "sha512" && algorithm != "curseforge" {
+		c.AbortWithStatusJSON(http.StatusBadRequest, gin.H{
+			"error": "Invalid algorithm. Must be sha512 or curseforge.",
+		})
+	}
+	fingerprints := make(map[string]string)
+	mutex := sync.RWMutex{}
+	wg := &sync.WaitGroup{}
+	wg.Add(len(paths))
+
+	for _, path := range paths {
+		path := path
+		go func() {
+			defer wg.Done()
+			p := strings.TrimLeft(path, "/")
+			f, st, err := s.Filesystem().File(p)
+			if err != nil {
+				mutex.Lock()
+				fingerprints[path] = ""
+				mutex.Unlock()
+				return
+			}
+			defer f.Close()
+			// Don't allow a named pipe to be opened.
+			//
+			// @see https://github.com/pterodactyl/panel/issues/4059
+			if st.Mode()&os.ModeNamedPipe != 0 {
+				return
+			}
+
+			r := bufio.NewReader(f)
+			buf := new(bytes.Buffer)
+			if _, err = buf.ReadFrom(r); err != nil {
+				return
+			}
+
+			hash := ""
+
+			if algorithm == "sha512" {
+				hashBytes := sha512.Sum512(buf.Bytes())
+				hash = hex.EncodeToString(hashBytes[:])
+			} else if algorithm == "curseforge" {
+				hash = filesystem.CalculateCurseForgeFingerprint(buf)
+			}
+
+			mutex.Lock()
+			fingerprints[path] = hash
+			mutex.Unlock()
+		}()
+	}
+
+	wg.Wait()
+
+	c.JSON(http.StatusOK, gin.H{
+		"fingerprints": fingerprints,
+	})
+}
+
 // Returns the contents of a directory for a server.
 func getServerListDirectory(c *gin.Context) {
 	s := ExtractServer(c)
diff --git a/server/filesystem/curseforge.go b/server/filesystem/curseforge.go
new file mode 100644
index 0000000..feba921
--- /dev/null
+++ b/server/filesystem/curseforge.go
@@ -0,0 +1,63 @@
+package filesystem
+
+import (
+	"bytes"
+	"strconv"
+)
+
+func isIgnoredInCurseForgeFingerprint(b byte) bool {
+	return b == '\t' || b == '\n' || b == '\r' || b == ' '
+}
+
+func computeCurseForgeFingerprintNormalizedLength(buf *bytes.Buffer) int {
+	var len_no_whitespace int = 0
+	bytes := buf.Bytes()
+
+	for i := 0; i < buf.Len(); i++ {
+		char := bytes[i]
+		if !isIgnoredInCurseForgeFingerprint(char) {
+			len_no_whitespace++
+		}
+	}
+
+	return len_no_whitespace
+}
+
+// https://github.com/meza/curseforge-fingerprint/blob/main/src/addon/fingerprint.cpp#L36
+func CalculateCurseForgeFingerprint(buf *bytes.Buffer) string {
+	const multiplex = 1540483477
+	len := buf.Len()
+	bytes := buf.Bytes()
+
+	var num1 uint32 = uint32(computeCurseForgeFingerprintNormalizedLength(buf))
+	var num2 uint32 = 1 ^ num1
+
+	var num3 uint32 = 0
+	var num4 uint32 = 0
+
+	for i := 0; i < len; i++ {
+		b := bytes[i]
+
+		if !isIgnoredInCurseForgeFingerprint(b) {
+			num3 |= uint32(b) << num4
+			num4 += 8
+
+			if num4 == 32 {
+				var num6 uint32 = num3 * multiplex
+				var num7 uint32 = (num6 ^ num6>>24) * multiplex
+
+				num2 = num2*multiplex ^ num7
+				num3 = 0
+				num4 = 0
+			}
+		}
+	}
+
+	if num4 > 0 {
+		num2 = (num2 ^ num3) * multiplex
+	}
+
+	num6 := (num2 ^ num2>>13) * multiplex
+
+	return strconv.FormatUint(uint64(num6^num6>>15), 10)
+}