diff options
| -rw-r--r-- | plugins/viewhtml/sanitize.go | 31 | ||||
| -rw-r--r-- | plugins/viewhtml/viewer.go | 11 |
2 files changed, 26 insertions, 16 deletions
diff --git a/plugins/viewhtml/sanitize.go b/plugins/viewhtml/sanitize.go index 8cee481..d5c94a7 100644 --- a/plugins/viewhtml/sanitize.go +++ b/plugins/viewhtml/sanitize.go @@ -6,6 +6,7 @@ import ( "regexp" "strings" + koushinbase "git.sr.ht/~emersion/koushin/plugins/base" "github.com/aymerick/douceur/css" cssparser "github.com/chris-ramon/douceur/parser" "github.com/microcosm-cc/bluemonday" @@ -68,7 +69,15 @@ var allowedStyles = map[string]bool{ "list-style-position": true, } -func sanitizeCSSDecls(decls []*css.Declaration) []*css.Declaration { +type sanitizer struct { + msg *koushinbase.IMAPMessage +} + +func (san *sanitizer) sanitizeResourceURL(src string) string { + return "about:blank" +} + +func (san *sanitizer) sanitizeCSSDecls(decls []*css.Declaration) []*css.Declaration { sanitized := make([]*css.Declaration, 0, len(decls)) for _, decl := range decls { if !allowedStyles[decl.Property] { @@ -86,26 +95,26 @@ func sanitizeCSSDecls(decls []*css.Declaration) []*css.Declaration { return sanitized } -func sanitizeCSSRule(rule *css.Rule) { +func (san *sanitizer) sanitizeCSSRule(rule *css.Rule) { // Disallow @import if rule.Kind == css.AtRule && strings.EqualFold(rule.Name, "@import") { rule.Prelude = "url(about:blank)" } - rule.Declarations = sanitizeCSSDecls(rule.Declarations) + rule.Declarations = san.sanitizeCSSDecls(rule.Declarations) for _, child := range rule.Rules { - sanitizeCSSRule(child) + san.sanitizeCSSRule(child) } } -func sanitizeNode(n *html.Node) { +func (san *sanitizer) sanitizeNode(n *html.Node) { if n.Type == html.ElementNode { if strings.EqualFold(n.Data, "img") { for i := range n.Attr { attr := &n.Attr[i] if strings.EqualFold(attr.Key, "src") { - attr.Val = "about:blank" + attr.Val = san.sanitizeResourceURL(attr.Val) } } } else if strings.EqualFold(n.Data, "style") { @@ -126,7 +135,7 @@ func sanitizeNode(n *html.Node) { s = "" } else { for _, rule := range stylesheet.Rules { - sanitizeCSSRule(rule) + san.sanitizeCSSRule(rule) } s = stylesheet.String() @@ -149,7 +158,7 @@ func sanitizeNode(n *html.Node) { continue } - decls = sanitizeCSSDecls(decls) + decls = san.sanitizeCSSDecls(decls) attr.Val = "" for _, d := range decls { @@ -160,17 +169,17 @@ func sanitizeNode(n *html.Node) { } for c := n.FirstChild; c != nil; c = c.NextSibling { - sanitizeNode(c) + san.sanitizeNode(c) } } -func sanitizeHTML(b []byte) ([]byte, error) { +func (san *sanitizer) sanitizeHTML(b []byte) ([]byte, error) { doc, err := html.Parse(bytes.NewReader(b)) if err != nil { return nil, fmt.Errorf("failed to parse HTML: %v", err) } - sanitizeNode(doc) + san.sanitizeNode(doc) var buf bytes.Buffer if err := html.Render(&buf, doc); err != nil { diff --git a/plugins/viewhtml/viewer.go b/plugins/viewhtml/viewer.go index 9734c37..47f5eea 100644 --- a/plugins/viewhtml/viewer.go +++ b/plugins/viewhtml/viewer.go @@ -12,7 +12,7 @@ import ( "github.com/emersion/go-message" ) -const tpl = ` +const tplSrc = ` <!-- allow-same-origin is required to resize the frame with its content --> <!-- allow-popups is required for target="_blank" links --> <iframe id="email-frame" srcdoc="{{.}}" sandbox="allow-same-origin allow-popups"></iframe> @@ -20,6 +20,8 @@ const tpl = ` <link rel="stylesheet" href="/plugins/viewhtml/assets/style.css"> ` +var tpl = template.Must(template.New("view-html.html").Parse(tplSrc)) + type viewer struct{} func (viewer) ViewMessagePart(ctx *koushin.Context, msg *koushinbase.IMAPMessage, part *message.Entity) (interface{}, error) { @@ -36,15 +38,14 @@ func (viewer) ViewMessagePart(ctx *koushin.Context, msg *koushinbase.IMAPMessage return nil, fmt.Errorf("failed to read part body: %v", err) } - body, err = sanitizeHTML(body) + san := sanitizer{msg} + body, err = san.sanitizeHTML(body) if err != nil { return nil, fmt.Errorf("failed to sanitize HTML part: %v", err) } - t := template.Must(template.New("view-html.html").Parse(tpl)) - var buf bytes.Buffer - err = t.Execute(&buf, string(body)) + err = tpl.Execute(&buf, string(body)) if err != nil { return nil, err } |