1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108
109. 109
110. 110
111. 111
112. 112
113. 113
114. 114
115. 115
116. 116
117. 117
118. 118

// Copyright 2023 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package pwn

import (
	"context"
	"crypto/sha1"
	"encoding/hex"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strconv"
	"strings"

	"code.gitea.io/gitea/modules/setting"
)

const passwordURL = "https://api.pwnedpasswords.com/range/"

// ErrEmptyPassword is an empty password error
var ErrEmptyPassword = errors.New("password cannot be empty")

// Client is a HaveIBeenPwned client
type Client struct {
	ctx  context.Context
	http *http.Client
}

// New returns a new HaveIBeenPwned Client
func New(options ...ClientOption) *Client {
	client := &Client{
		ctx:  context.Background(),
		http: http.DefaultClient,
	}

	for _, opt := range options {
		opt(client)
	}

	return client
}

// ClientOption is a way to modify a new Client
type ClientOption func(*Client)

// WithHTTP will set the http.Client of a Client
func WithHTTP(httpClient *http.Client) func(pwnClient *Client) {
	return func(pwnClient *Client) {
		pwnClient.http = httpClient
	}
}

// WithContext will set the context.Context of a Client
func WithContext(ctx context.Context) func(pwnClient *Client) {
	return func(pwnClient *Client) {
		pwnClient.ctx = ctx
	}
}

func newRequest(ctx context.Context, method, url string, body io.ReadCloser) (*http.Request, error) {
	req, err := http.NewRequestWithContext(ctx, method, url, body)
	if err != nil {
		return nil, err
	}
	req.Header.Add("User-Agent", "Gitea "+setting.AppVer)
	return req, nil
}

// CheckPassword returns the number of times a password has been compromised
// Adding padding will make requests more secure, however is also slower
// because artificial responses will be added to the response
// For more information, see https://www.troyhunt.com/enhancing-pwned-passwords-privacy-with-padding/
func (c *Client) CheckPassword(pw string, padding bool) (int, error) {
	if strings.TrimSpace(pw) == "" {
		return -1, ErrEmptyPassword
	}

	sha := sha1.New()
	sha.Write([]byte(pw))
	enc := hex.EncodeToString(sha.Sum(nil))
	prefix, suffix := enc[:5], enc[5:]

	req, err := newRequest(c.ctx, http.MethodGet, fmt.Sprintf("%s%s", passwordURL, prefix), nil)
	if err != nil {
		return -1, nil
	}
	if padding {
		req.Header.Add("Add-Padding", "true")
	}

	resp, err := c.http.Do(req)
	if err != nil {
		return -1, err
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return -1, err
	}
	defer resp.Body.Close()

	for _, pair := range strings.Split(string(body), "\n") {
		parts := strings.Split(pair, ":")
		if len(parts) != 2 {
			continue
		}
		if strings.EqualFold(suffix, parts[0]) {
			count, err := strconv.ParseInt(strings.TrimSpace(parts[1]), 10, 64)
			if err != nil {
				return -1, err
			}
			return int(count), nil
		}
	}
	return 0, nil
}