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
|
package middleware
import (
"errors"
"net/http"
"strings"
"github.com/labstack/echo/v4"
)
type (
// KeyAuthConfig defines the config for KeyAuth middleware.
KeyAuthConfig struct {
// Skipper defines a function to skip middleware.
Skipper Skipper
// KeyLookup is a string in the form of "<source>:<name>" that is used
// to extract key from the request.
// Optional. Default value "header:Authorization".
// Possible values:
// - "header:<name>"
// - "query:<name>"
// - "form:<name>"
KeyLookup string `yaml:"key_lookup"`
// AuthScheme to be used in the Authorization header.
// Optional. Default value "Bearer".
AuthScheme string
// Validator is a function to validate key.
// Required.
Validator KeyAuthValidator
}
// KeyAuthValidator defines a function to validate KeyAuth credentials.
KeyAuthValidator func(string, echo.Context) (bool, error)
keyExtractor func(echo.Context) (string, error)
)
var (
// DefaultKeyAuthConfig is the default KeyAuth middleware config.
DefaultKeyAuthConfig = KeyAuthConfig{
Skipper: DefaultSkipper,
KeyLookup: "header:" + echo.HeaderAuthorization,
AuthScheme: "Bearer",
}
)
// KeyAuth returns an KeyAuth middleware.
//
// For valid key it calls the next handler.
// For invalid key, it sends "401 - Unauthorized" response.
// For missing key, it sends "400 - Bad Request" response.
func KeyAuth(fn KeyAuthValidator) echo.MiddlewareFunc {
c := DefaultKeyAuthConfig
c.Validator = fn
return KeyAuthWithConfig(c)
}
// KeyAuthWithConfig returns an KeyAuth middleware with config.
// See `KeyAuth()`.
func KeyAuthWithConfig(config KeyAuthConfig) echo.MiddlewareFunc {
// Defaults
if config.Skipper == nil {
config.Skipper = DefaultKeyAuthConfig.Skipper
}
// Defaults
if config.AuthScheme == "" {
config.AuthScheme = DefaultKeyAuthConfig.AuthScheme
}
if config.KeyLookup == "" {
config.KeyLookup = DefaultKeyAuthConfig.KeyLookup
}
if config.Validator == nil {
panic("echo: key-auth middleware requires a validator function")
}
// Initialize
parts := strings.Split(config.KeyLookup, ":")
extractor := keyFromHeader(parts[1], config.AuthScheme)
switch parts[0] {
case "query":
extractor = keyFromQuery(parts[1])
case "form":
extractor = keyFromForm(parts[1])
}
return func(next echo.HandlerFunc) echo.HandlerFunc {
return func(c echo.Context) error {
if config.Skipper(c) {
return next(c)
}
// Extract and verify key
key, err := extractor(c)
if err != nil {
return echo.NewHTTPError(http.StatusBadRequest, err.Error())
}
valid, err := config.Validator(key, c)
if err != nil {
return err
} else if valid {
return next(c)
}
return echo.ErrUnauthorized
}
}
}
// keyFromHeader returns a `keyExtractor` that extracts key from the request header.
func keyFromHeader(header string, authScheme string) keyExtractor {
return func(c echo.Context) (string, error) {
auth := c.Request().Header.Get(header)
if auth == "" {
return "", errors.New("missing key in request header")
}
if header == echo.HeaderAuthorization {
l := len(authScheme)
if len(auth) > l+1 && auth[:l] == authScheme {
return auth[l+1:], nil
}
return "", errors.New("invalid key in the request header")
}
return auth, nil
}
}
// keyFromQuery returns a `keyExtractor` that extracts key from the query string.
func keyFromQuery(param string) keyExtractor {
return func(c echo.Context) (string, error) {
key := c.QueryParam(param)
if key == "" {
return "", errors.New("missing key in the query string")
}
return key, nil
}
}
// keyFromForm returns a `keyExtractor` that extracts key from the form.
func keyFromForm(param string) keyExtractor {
return func(c echo.Context) (string, error) {
key := c.FormValue(param)
if key == "" {
return "", errors.New("missing key in the form")
}
return key, nil
}
}
|
