Reorganize packages, closes #79

- All packages go into either cmd or pkg directories
- Most packages renamed
- Server packages moved into pkg/server
- sanitize moved into webui, as that's the only place it's used
- filestore moved into pkg/storage/file
- Makefile updated, and PKG variable use fixed

pkg/webui/sanitize/css.go

@@ -0,0 +1,110 @@
+package sanitize
+
+import (
+	"bytes"
+	"strings"
+
+	"github.com/gorilla/css/scanner"
+)
+
+// propertyRule may someday allow control of what values are valid for a particular property.
+type propertyRule struct{}
+
+var allowedProperties = map[string]propertyRule{
+	"align":            {},
+	"background-color": {},
+	"border":           {},
+	"border-bottom":    {},
+	"border-left":      {},
+	"border-radius":    {},
+	"border-right":     {},
+	"border-top":       {},
+	"box-sizing":       {},
+	"clear":            {},
+	"color":            {},
+	"content":          {},
+	"display":          {},
+	"font-family":      {},
+	"font-size":        {},
+	"font-weight":      {},
+	"height":           {},
+	"line-height":      {},
+	"margin":           {},
+	"margin-bottom":    {},
+	"margin-left":      {},
+	"margin-right":     {},
+	"margin-top":       {},
+	"max-height":       {},
+	"max-width":        {},
+	"overflow":         {},
+	"padding":          {},
+	"padding-bottom":   {},
+	"padding-left":     {},
+	"padding-right":    {},
+	"padding-top":      {},
+	"table-layout":     {},
+	"text-align":       {},
+	"text-decoration":  {},
+	"text-shadow":      {},
+	"vertical-align":   {},
+	"width":            {},
+	"word-break":       {},
+}
+
+// Handler Token, return next state.
+type stateHandler func(b *bytes.Buffer, t *scanner.Token) stateHandler
+
+func sanitizeStyle(input string) string {
+	b := &bytes.Buffer{}
+	scan := scanner.New(input)
+	state := stateStart
+	for {
+		t := scan.Next()
+		if t.Type == scanner.TokenEOF {
+			return b.String()
+		}
+		if t.Type == scanner.TokenError {
+			return ""
+		}
+		state = state(b, t)
+		if state == nil {
+			return ""
+		}
+	}
+}
+
+func stateStart(b *bytes.Buffer, t *scanner.Token) stateHandler {
+	switch t.Type {
+	case scanner.TokenIdent:
+		_, ok := allowedProperties[strings.ToLower(t.Value)]
+		if !ok {
+			return stateEat
+		}
+		b.WriteString(t.Value)
+		return stateValid
+	case scanner.TokenS:
+		return stateStart
+	}
+	// Unexpected type.
+	b.WriteString("/*" + t.Type.String() + "*/")
+	return stateEat
+}
+
+func stateEat(b *bytes.Buffer, t *scanner.Token) stateHandler {
+	if t.Type == scanner.TokenChar && t.Value == ";" {
+		// Done eating.
+		return stateStart
+	}
+	// Throw away this token.
+	return stateEat
+}
+
+func stateValid(b *bytes.Buffer, t *scanner.Token) stateHandler {
+	state := stateValid
+	if t.Type == scanner.TokenChar && t.Value == ";" {
+		// End of property.
+		state = stateStart
+	}
+	b.WriteString(t.Value)
+	return state
+}

pkg/webui/sanitize/css_test.go

@@ -0,0 +1,34 @@
+package sanitize
+
+import (
+	"testing"
+)
+
+func TestSanitizeStyle(t *testing.T) {
+	testCases := []struct {
+		input, want string
+	}{
+		{"", ""},
+		{
+			"color: red;",
+			"color: red;",
+		},
+		{
+			"background-color: black; color: white",
+			"background-color: black;color: white",
+		},
+		{
+			"background-color: black; invalid: true; color: white",
+			"background-color: black;color: white",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.input, func(t *testing.T) {
+			got := sanitizeStyle(tc.input)
+			if got != tc.want {
+				t.Errorf("got: %q, want: %q, input: %q", got, tc.want, tc.input)
+			}
+		})
+	}
+
+}

pkg/webui/sanitize/html.go

@@ -0,0 +1,88 @@
+package sanitize
+
+import (
+	"bufio"
+	"bytes"
+	"io"
+	"regexp"
+	"strings"
+
+	"github.com/microcosm-cc/bluemonday"
+	"golang.org/x/net/html"
+)
+
+var (
+	cssSafe = regexp.MustCompile(".*")
+	policy  = bluemonday.UGCPolicy().
+		AllowElements("center").
+		AllowAttrs("style").Matching(cssSafe).Globally()
+)
+
+func HTML(html string) (output string, err error) {
+	output, err = sanitizeStyleTags(html)
+	if err != nil {
+		return "", err
+	}
+	output = policy.Sanitize(output)
+	return
+}
+
+func sanitizeStyleTags(input string) (string, error) {
+	r := strings.NewReader(input)
+	b := &bytes.Buffer{}
+	if err := styleTagFilter(b, r); err != nil {
+		return "", err
+	}
+	return b.String(), nil
+}
+
+func styleTagFilter(w io.Writer, r io.Reader) error {
+	bw := bufio.NewWriter(w)
+	b := make([]byte, 256)
+	z := html.NewTokenizer(r)
+	for {
+		b = b[:0]
+		tt := z.Next()
+		switch tt {
+		case html.ErrorToken:
+			err := z.Err()
+			if err == io.EOF {
+				return bw.Flush()
+			}
+			return err
+		case html.StartTagToken, html.SelfClosingTagToken:
+			name, hasAttr := z.TagName()
+			if !hasAttr {
+				bw.Write(z.Raw())
+				continue
+			}
+			b = append(b, '<')
+			b = append(b, name...)
+			for {
+				key, val, more := z.TagAttr()
+				strval := string(val)
+				style := false
+				if strings.ToLower(string(key)) == "style" {
+					style = true
+					strval = sanitizeStyle(strval)
+				}
+				if !style || strval != "" {
+					b = append(b, ' ')
+					b = append(b, key...)
+					b = append(b, '=', '"')
+					b = append(b, []byte(html.EscapeString(strval))...)
+					b = append(b, '"')
+				}
+				if !more {
+					break
+				}
+			}
+			if tt == html.SelfClosingTagToken {
+				b = append(b, '/')
+			}
+			bw.Write(append(b, '>'))
+		default:
+			bw.Write(z.Raw())
+		}
+	}
+}

pkg/webui/sanitize/html_test.go

@@ -0,0 +1,171 @@
+package sanitize_test
+
+import (
+	"testing"
+
+	"github.com/jhillyerd/inbucket/pkg/webui/sanitize"
+)
+
+// TestHTMLPlainStrings test plain text passthrough
+func TestHTMLPlainStrings(t *testing.T) {
+	testStrings := []string{
+		"",
+		"plain string",
+		"one < two",
+	}
+	for _, ts := range testStrings {
+		t.Run(ts, func(t *testing.T) {
+			got, err := sanitize.HTML(ts)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got != ts {
+				t.Errorf("Got: %q, want: %q", got, ts)
+			}
+		})
+	}
+}
+
+// TestHTMLSimpleFormatting tests basic tags we should allow
+func TestHTMLSimpleFormatting(t *testing.T) {
+	testStrings := []string{
+		"<p>paragraph</p>",
+		"<b>bold</b>",
+		"<i>italic</b>",
+		"<em>emphasis</em>",
+		"<strong>strong</strong>",
+		"<div><span>text</span></div>",
+		"<center>text</center>",
+	}
+	for _, ts := range testStrings {
+		t.Run(ts, func(t *testing.T) {
+			got, err := sanitize.HTML(ts)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got != ts {
+				t.Errorf("Got: %q, want: %q", got, ts)
+			}
+		})
+	}
+}
+
+// TestHTMLScriptTags tests some strings with JavaScript
+func TestHTMLScriptTags(t *testing.T) {
+	testCases := []struct {
+		input, want string
+	}{
+		{
+			`safe<script>nope</script>`,
+			`safe`,
+		},
+		{
+			`<a onblur="alert(something)" href="http://mysite.com">mysite</a>`,
+			`<a href="http://mysite.com" rel="nofollow">mysite</a>`,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.input, func(t *testing.T) {
+			got, err := sanitize.HTML(tc.input)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got != tc.want {
+				t.Errorf("Got: %q, want: %q", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestSanitizeStyleTags(t *testing.T) {
+	testCases := []struct {
+		name, input, want string
+	}{
+		{
+			"empty",
+			``,
+			``,
+		},
+		{
+			"open",
+			`<div>`,
+			`<div>`,
+		},
+		{
+			"open close",
+			`<div></div>`,
+			`<div></div>`,
+		},
+		{
+			"inner text",
+			`<div>foo bar</div>`,
+			`<div>foo bar</div>`,
+		},
+		{
+			"self close",
+			`<br/>`,
+			`<br/>`,
+		},
+		{
+			"open params",
+			`<div id="me">`,
+			`<div id="me">`,
+		},
+		{
+			"open params squote",
+			`<div id="me" title='best'>`,
+			`<div id="me" title="best">`,
+		},
+		{
+			"open style",
+			`<div id="me" style="color: red;">`,
+			`<div id="me" style="color: red;">`,
+		},
+		{
+			"open style squote",
+			`<div id="me" style='color: red;'>`,
+			`<div id="me" style="color: red;">`,
+		},
+		{
+			"open style mixed case",
+			`<div id="me" StYlE="color: red;">`,
+			`<div id="me" style="color: red;">`,
+		},
+		{
+			"closed style",
+			`<br style="border: 1px solid red;"/>`,
+			`<br style="border: 1px solid red;"/>`,
+		},
+		{
+			"mixed case style",
+			`<br StYlE="border: 1px solid red;"/>`,
+			`<br style="border: 1px solid red;"/>`,
+		},
+		{
+			"mixed case invalid style",
+			`<br StYlE="position: fixed;"/>`,
+			`<br/>`,
+		},
+		{
+			"mixed",
+			`<p id='i' title="cla'zz" style="font-size: 25px;"><b>some text</b></p>`,
+			`<p id="i" title="cla&#39;zz" style="font-size: 25px;"><b>some text</b></p>`,
+		},
+		{
+			"invalid styles",
+			`<div id="me" style='position: absolute;'>`,
+			`<div id="me">`,
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := sanitize.HTML(tc.input)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if got != tc.want {
+				t.Errorf("input: %s\ngot : %s\nwant: %s", tc.input, got, tc.want)
+			}
+		})
+	}
+}