summaryrefslogtreecommitdiff
path: root/spec/lib/banzai/filter/external_link_filter_spec.rb
blob: 2acbe05f0828ea3159e2ae0185b23a97f9e306e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
require 'spec_helper'

shared_examples 'an external link with rel attribute' do
  it 'adds rel="nofollow" to external links' do
    expect(doc.at_css('a')).to have_attribute('rel')
    expect(doc.at_css('a')['rel']).to include 'nofollow'
  end

  it 'adds rel="noreferrer" to external links' do
    expect(doc.at_css('a')).to have_attribute('rel')
    expect(doc.at_css('a')['rel']).to include 'noreferrer'
  end

  it 'adds rel="noopener" to external links' do
    expect(doc.at_css('a')).to have_attribute('rel')
    expect(doc.at_css('a')['rel']).to include 'noopener'
  end
end

describe Banzai::Filter::ExternalLinkFilter do
  include FilterSpecHelper

  it 'ignores elements without an href attribute' do
    exp = act = %q(<a id="ignored">Ignore Me</a>)
    expect(filter(act).to_html).to eq exp
  end

  it 'ignores non-HTTP(S) links' do
    exp = act = %q(<a href="irc://irc.freenode.net/gitlab">IRC</a>)
    expect(filter(act).to_html).to eq exp
  end

  it 'skips internal links' do
    internal = Gitlab.config.gitlab.url
    exp = act = %Q(<a href="#{internal}/sign_in">Login</a>)
    expect(filter(act).to_html).to eq exp
  end

  context 'for root links on document' do
    let(:doc) { filter %q(<a href="https://google.com/">Google</a>) }

    it_behaves_like 'an external link with rel attribute'
  end

  context 'for nested links on document' do
    let(:doc) { filter %q(<p><a href="https://google.com/">Google</a></p>) }

    it_behaves_like 'an external link with rel attribute'
  end

  context 'for invalid urls' do
    it 'adds rel and target attributes to broken hrefs' do
      doc = filter %q(<p><a href="don't crash on broken urls">Google</a></p>)
      expected = %q(<p><a href="don't%20crash%20on%20broken%20urls" rel="nofollow noreferrer noopener" target="_blank">Google</a></p>)

      expect(doc.to_html).to eq(expected)
    end

    it 'adds rel and target to improperly formatted mailtos' do
      doc = filter %q(<p><a href="mailto://jblogs@example.com">Email</a></p>)
      expected = %q(<p><a href="mailto://jblogs@example.com" rel="nofollow noreferrer noopener" target="_blank">Email</a></p>)

      expect(doc.to_html).to eq(expected)
    end

    it 'adds rel and target to improperly formatted autolinks' do
      doc = filter %q(<p><a href="mailto://jblogs@example.com">mailto://jblogs@example.com</a></p>)
      expected = %q(<p><a href="mailto://jblogs@example.com" rel="nofollow noreferrer noopener" target="_blank">mailto://jblogs@example.com</a></p>)

      expect(doc.to_html).to eq(expected)
    end
  end

  context 'for links with a username' do
    context 'with a valid username' do
      let(:doc) { filter %q(<a href="https://user@google.com/">Google</a>) }

      it_behaves_like 'an external link with rel attribute'
    end

    context 'with an impersonated username' do
      let(:internal) { Gitlab.config.gitlab.url }

      let(:doc) { filter %Q(<a href="https://#{internal}@example.com" target="_blank">Reverse Tabnabbing</a>) }

      it_behaves_like 'an external link with rel attribute'
    end
  end

  context 'for non-lowercase scheme links' do
    context 'with http' do
      let(:doc) { filter %q(<p><a href="httP://google.com/">Google</a></p>) }

      it_behaves_like 'an external link with rel attribute'
    end

    context 'with https' do
      let(:doc) { filter %q(<p><a href="hTTpS://google.com/">Google</a></p>) }

      it_behaves_like 'an external link with rel attribute'
    end

    it 'skips internal links' do
      internal_link = Gitlab.config.gitlab.url + "/sign_in"
      url = internal_link.gsub(/\Ahttp/, 'HtTp')
      act = %Q(<a href="#{url}">Login</a>)
      exp = %Q(<a href="#{internal_link}">Login</a>)
      expect(filter(act).to_html).to eq(exp)
    end

    it 'skips relative links' do
      exp = act = %q(<a href="http_spec/foo.rb">Relative URL</a>)
      expect(filter(act).to_html).to eq(exp)
    end
  end

  context 'for protocol-relative links' do
    let(:doc) { filter %q(<p><a href="//google.com/">Google</a></p>) }

    it_behaves_like 'an external link with rel attribute'
  end

  context 'links with RTLO character' do
    # In rendered text this looks like "http://example.com/evilexe.mp3"
    let(:doc) { filter %Q(<a href="http://example.com/evil%E2%80%AE3pm.exe">http://example.com/evil\u202E3pm.exe</a>) }

    it_behaves_like 'an external link with rel attribute'

    it 'escapes RTLO in link text' do
      expected = %q(http://example.com/evil%E2%80%AE3pm.exe</a>)

      expect(doc.to_html).to include(expected)
    end

    it 'does not mangle the link text' do
      doc = filter %Q(<a href="http://example.com">One<span>and</span>\u202Eexe.mp3</a>)

      expect(doc.to_html).to include('One<span>and</span>%E2%80%AEexe.mp3</a>')
    end
  end

  context 'for generated autolinks' do
    context 'with an IDN character' do
      let(:doc)       { filter(%q(<a href="http://exa%F0%9F%98%84mple.com">http://exa😄mple.com</a>)) }
      let(:doc_email) { filter(%q(<a href="http://exa%F0%9F%98%84mple.com">http://exa😄mple.com</a>), emailable_links: true) }

      it_behaves_like 'an external link with rel attribute'

      it 'does not change the link text' do
        expect(doc.to_html).to include('http://exa😄mple.com</a>')
      end

      it 'uses punycode for emails' do
        expect(doc_email.to_html).to include('http://xn--example-6p25f.com/</a>')
      end
    end
  end

  context 'for links that look malicious' do
    context 'with an IDN character' do
      let(:doc) { filter %q(<a href="http://exa%F0%9F%98%84mple.com">http://exa😄mple.com</a>) }

      it 'adds a toolip with punycode' do
        expect(doc.to_html).to include('http://exa😄mple.com</a>')
        expect(doc.to_html).to include('class="has-tooltip"')
        expect(doc.to_html).to include('title="http://xn--example-6p25f.com/"')
      end
    end

    context 'with RTLO character' do
      let(:doc) { filter %q(<a href="http://example.com/evil%E2%80%AE3pm.exe">Evil Test</a>) }

      it 'adds a toolip with punycode' do
        expect(doc.to_html).to include('Evil Test</a>')
        expect(doc.to_html).to include('class="has-tooltip"')
        expect(doc.to_html).to include('title="http://example.com/evil%E2%80%AE3pm.exe"')
      end
    end
  end
end