Fix SSH signing key path will be displayed in the pull request UI

Author: ChristopherHX

routers/web/repo/issue_view.go

@@ -8,10 +8,12 @@ import (
 	"math/big"
 	"net/http"
 	"net/url"
+	"os"
 	"sort"
 	"strconv"
 
 	activities_model "code.gitea.io/gitea/models/activities"
+	asymkey_model "code.gitea.io/gitea/models/asymkey"
 	"code.gitea.io/gitea/models/db"
 	git_model "code.gitea.io/gitea/models/git"
 	issues_model "code.gitea.io/gitea/models/issues"
@@ -494,7 +496,24 @@ func preparePullViewSigning(ctx *context.Context, issue *issues_model.Issue) {
 	if ctx.Doer != nil {
 		sign, key, _, err := asymkey_service.SignMerge(ctx, pull, ctx.Doer, pull.BaseRepo.RepoPath(), pull.BaseBranch, pull.GetGitHeadRefName())
 		ctx.Data["WillSign"] = sign
-		ctx.Data["SigningKey"] = key
+		switch key.Format {
+		case git.SigningKeyFormatOpenPGP:
+			ctx.Data["SigningKey"] = key.KeyID
+		case git.SigningKeyFormatSSH:
+			content, readErr := os.ReadFile(key.KeyID)
+			if readErr != nil {
+				log.Error("Error whilst reading public key of pr %d in repo %s. Error: %v", pull.ID, pull.BaseRepo.FullName(), readErr)
+				ctx.Data["SigningKey"] = "Unknown"
+			} else {
+				var fingerprintErr error
+				ctx.Data["SigningKey"], fingerprintErr = asymkey_model.CalcFingerprint(string(content))
+				if fingerprintErr != nil {
+					log.Error("Error whilst generating public key fingerprint of pr %d in repo %s. Error: %v", pull.ID, pull.BaseRepo.FullName(), fingerprintErr)
+				} else {
+					ctx.Data["SigningKey"] = "Unknown"
+				}
+			}
+		}
 		if err != nil {
 			if asymkey_service.IsErrWontSign(err) {
 				ctx.Data["WontSignReason"] = err.(*asymkey_service.ErrWontSign).Reason