fix: strip double quotes from sftp.args flags to prevent restic parse error

Wahaj Ahmed · Wahaj Ahmed · commit 1f9a607fc064 · 2026-05-21T00:26:55.000+02:00
The UI constructs sftp.args flags with double-quoted paths (e.g. -i "/root/.ssh/key"), which causes restic's pflag parser to fail with 'bare " in non-quoted-field'. The sanitizeRepoFlags function now strips double quotes from sftp.args values since they are not needed when passed as sftp subcommand arguments. Fixes #1227
diff --git a/internal/api/backresthandler.go b/internal/api/backresthandler.go
@@ -990,7 +990,16 @@ func (s *BackrestHandler) GeneratePairingToken(ctx context.Context, req *connect
 func sanitizeRepoFlags(repo *v1.Repo) {
 	for i, flag := range repo.Flags {
 		if strings.HasPrefix(flag, "--option=sftp.args=") {
-			repo.Flags[i] = strings.ReplaceAll(flag, "-i @", "-i ")
+			// Remove the "-i @" workaround since we now handle quoting properly
+			flag = strings.ReplaceAll(flag, "-i @", "-i ")
+			// Strip double quotes from sftp.args values that cause restic's
+			// pflag parser to fail with "bare \" in non-quoted-field".
+			// The UI wraps paths in double quotes (e.g. -i "/path/to/key"),
+			// but restic's --option flag parser cannot handle them.
+			// Paths passed as sftp.args don't need quoting since they are
+			// passed directly to sftp as individual arguments.
+			flag = strings.ReplaceAll(flag, "\"", "")
+			repo.Flags[i] = flag
 		}
 	}
 }
diff --git a/internal/api/backresthandler_test.go b/internal/api/backresthandler_test.go
@@ -1123,3 +1123,52 @@ func getOperations(t *testing.T, log *oplog.OpLog) []*v1.Operation {
 	}
 	return operations
 }
+
+func TestSanitizeRepoFlags(t *testing.T) {
+	tests := []struct {
+		name  string
+		flags []string
+		want  []string
+	}{
+		{
+			name:  "strip double quotes from sftp.args",
+			flags: []string{`--option=sftp.args='-oBatchMode=yes -i "/root/.ssh/id_ed25519" -p 23 -oUserKnownHostsFile="/root/.ssh/known_hosts"'`},
+			want:  []string{`--option=sftp.args='-oBatchMode=yes -i /root/.ssh/id_ed25519 -p 23 -oUserKnownHostsFile=/root/.ssh/known_hosts'`},
+		},
+		{
+			name:  "strip double quotes with -i @ workaround",
+			flags: []string{`--option=sftp.args='-oBatchMode=yes -i @/root/.ssh/id_ed25519"'`},
+			want:  []string{`--option=sftp.args='-oBatchMode=yes -i /root/.ssh/id_ed25519'`},
+		},
+		{
+			name:  "no sftp.args flags unchanged",
+			flags: []string{`--option=some.other=value`},
+			want:  []string{`--option=some.other=value`},
+		},
+		{
+			name:  "sftp.args without double quotes unchanged",
+			flags: []string{`--option=sftp.args=-oBatchMode=yes`},
+			want:  []string{`--option=sftp.args=-oBatchMode=yes`},
+		},
+		{
+			name:  "mixed flags only sftp.args modified",
+			flags: []string{`--option=other=val`, `--option=sftp.args='-i "/path/key"'`},
+			want:  []string{`--option=other=val`, `--option=sftp.args=-i /path/key`},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			repo := &v1.Repo{Flags: tt.flags}
+			sanitizeRepoFlags(repo)
+			if len(repo.Flags) != len(tt.want) {
+				t.Fatalf("got %d flags, want %d", len(repo.Flags), len(tt.want))
+			}
+			for i, got := range repo.Flags {
+				if got != tt.want[i] {
+					t.Errorf("flags[%d] = %q, want %q", i, got, tt.want[i])
+				}
+			}
+		})
+	}
+}

Original file line number	Diff line number	Diff line change
`@@ -990,7 +990,16 @@ func (s BackrestHandler) GeneratePairingToken(ctx context.Context, req connect`
`990`	`990`	`func sanitizeRepoFlags(repo *v1.Repo) {`
`991`	`991`	`for i, flag := range repo.Flags {`
`992`	`992`	`if strings.HasPrefix(flag, "--option=sftp.args=") {`
`993`		`- repo.Flags[i] = strings.ReplaceAll(flag, "-i @", "-i ")`
	`993`	`+ // Remove the "-i @" workaround since we now handle quoting properly`
	`994`	`+ flag = strings.ReplaceAll(flag, "-i @", "-i ")`
	`995`	`+ // Strip double quotes from sftp.args values that cause restic's`
	`996`	`+ // pflag parser to fail with "bare \" in non-quoted-field".`
	`997`	`+ // The UI wraps paths in double quotes (e.g. -i "/path/to/key"),`
	`998`	`+ // but restic's --option flag parser cannot handle them.`
	`999`	`+ // Paths passed as sftp.args don't need quoting since they are`
	`1000`	`+ // passed directly to sftp as individual arguments.`
	`1001`	`+ flag = strings.ReplaceAll(flag, "\"", "")`
	`1002`	`+ repo.Flags[i] = flag`
`994`	`1003`	`}`
`995`	`1004`	`}`
`996`	`1005`	`}`