From c941e27e70c3e06e1011d2dd71d72a7a06a9bcbc Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Thu, 15 Feb 2018 15:57:13 -0800 Subject: [PATCH] cmd/go: restrict meta imports to valid schemes Before this change, when using -insecure, we permitted any meta import repo root as long as it contained "://". When not using -insecure, we restrict meta import repo roots to be valid URLs. People may depend on that somehow, so permit meta import repo roots to be invalid URLs, but require them to have valid schemes per RFC 3986. Fixes #23867 Change-Id: Iac666dfc75ac321bf8639dda5b0dba7c8840922d Reviewed-on: https://go-review.googlesource.com/94603 Reviewed-by: Brad Fitzpatrick --- src/cmd/go/internal/get/vcs.go | 34 +++++++++++++++++++++++++++-- src/cmd/go/internal/get/vcs_test.go | 43 +++++++++++++++++++++++++++++++++++++ 2 files changed, 75 insertions(+), 2 deletions(-) diff --git a/src/cmd/go/internal/get/vcs.go b/src/cmd/go/internal/get/vcs.go index ee6b16a1369..dced0ed8db5 100644 --- a/src/cmd/go/internal/get/vcs.go +++ b/src/cmd/go/internal/get/vcs.go @@ -809,8 +809,8 @@ func repoRootForImportDynamic(importPath string, security web.SecurityMode) (*re } } - if !strings.Contains(mmi.RepoRoot, "://") { - return nil, fmt.Errorf("%s: invalid repo root %q; no scheme", urlStr, mmi.RepoRoot) + if err := validateRepoRootScheme(mmi.RepoRoot); err != nil { + return nil, fmt.Errorf("%s: invalid repo root %q: %v", urlStr, mmi.RepoRoot, err) } rr := &repoRoot{ vcs: vcsByCmd(mmi.VCS), @@ -824,6 +824,36 @@ func repoRootForImportDynamic(importPath string, security web.SecurityMode) (*re return rr, nil } +// validateRepoRootScheme returns an error if repoRoot does not seem +// to have a valid URL scheme. At this point we permit things that +// aren't valid URLs, although later, if not using -insecure, we will +// restrict repoRoots to be valid URLs. This is only because we've +// historically permitted them, and people may depend on that. +func validateRepoRootScheme(repoRoot string) error { + end := strings.Index(repoRoot, "://") + if end <= 0 { + return errors.New("no scheme") + } + + // RFC 3986 section 3.1. + for i := 0; i < end; i++ { + c := repoRoot[i] + switch { + case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z': + // OK. + case '0' <= c && c <= '9' || c == '+' || c == '-' || c == '.': + // OK except at start. + if i == 0 { + return errors.New("invalid scheme") + } + default: + return errors.New("invalid scheme") + } + } + + return nil +} + var fetchGroup singleflight.Group var ( fetchCacheMu sync.Mutex diff --git a/src/cmd/go/internal/get/vcs_test.go b/src/cmd/go/internal/get/vcs_test.go index 2cb611fabd8..ece78b563ce 100644 --- a/src/cmd/go/internal/get/vcs_test.go +++ b/src/cmd/go/internal/get/vcs_test.go @@ -416,3 +416,46 @@ func TestMatchGoImport(t *testing.T) { } } } + +func TestValidateRepoRootScheme(t *testing.T) { + tests := []struct { + root string + err string + }{ + { + root: "", + err: "no scheme", + }, + { + root: "http://", + err: "", + }, + { + root: "a://", + err: "", + }, + { + root: "a#://", + err: "invalid scheme", + }, + { + root: "-config://", + err: "invalid scheme", + }, + } + + for _, test := range tests { + err := validateRepoRootScheme(test.root) + if err == nil { + if test.err != "" { + t.Errorf("validateRepoRootScheme(%q) = nil, want %q", test.root, test.err) + } + } else if test.err == "" { + if err != nil { + t.Errorf("validateRepoRootScheme(%q) = %q, want nil", test.root, test.err) + } + } else if err.Error() != test.err { + t.Errorf("validateRepoRootScheme(%q) = %q, want %q", test.root, err, test.err) + } + } +}