mirror of
https://github.com/labstack/echo.git
synced 2024-12-24 20:14:31 +02:00
4a1ccdfdc5
* CSRF, JWT, KeyAuth middleware support for multivalue value extractors * Add flag to JWT and KeyAuth middleware to allow continuing execution `next(c)` when error handler decides to swallow the error (returns nil).
185 lines
5.9 KiB
Go
185 lines
5.9 KiB
Go
package middleware
|
|
|
|
import (
|
|
"errors"
|
|
"fmt"
|
|
"github.com/labstack/echo/v4"
|
|
"net/textproto"
|
|
"strings"
|
|
)
|
|
|
|
const (
|
|
// extractorLimit is arbitrary number to limit values extractor can return. this limits possible resource exhaustion
|
|
// attack vector
|
|
extractorLimit = 20
|
|
)
|
|
|
|
var errHeaderExtractorValueMissing = errors.New("missing value in request header")
|
|
var errHeaderExtractorValueInvalid = errors.New("invalid value in request header")
|
|
var errQueryExtractorValueMissing = errors.New("missing value in the query string")
|
|
var errParamExtractorValueMissing = errors.New("missing value in path params")
|
|
var errCookieExtractorValueMissing = errors.New("missing value in cookies")
|
|
var errFormExtractorValueMissing = errors.New("missing value in the form")
|
|
|
|
// ValuesExtractor defines a function for extracting values (keys/tokens) from the given context.
|
|
type ValuesExtractor func(c echo.Context) ([]string, error)
|
|
|
|
func createExtractors(lookups string, authScheme string) ([]ValuesExtractor, error) {
|
|
if lookups == "" {
|
|
return nil, nil
|
|
}
|
|
sources := strings.Split(lookups, ",")
|
|
var extractors = make([]ValuesExtractor, 0)
|
|
for _, source := range sources {
|
|
parts := strings.Split(source, ":")
|
|
if len(parts) < 2 {
|
|
return nil, fmt.Errorf("extractor source for lookup could not be split into needed parts: %v", source)
|
|
}
|
|
|
|
switch parts[0] {
|
|
case "query":
|
|
extractors = append(extractors, valuesFromQuery(parts[1]))
|
|
case "param":
|
|
extractors = append(extractors, valuesFromParam(parts[1]))
|
|
case "cookie":
|
|
extractors = append(extractors, valuesFromCookie(parts[1]))
|
|
case "form":
|
|
extractors = append(extractors, valuesFromForm(parts[1]))
|
|
case "header":
|
|
prefix := ""
|
|
if len(parts) > 2 {
|
|
prefix = parts[2]
|
|
} else if authScheme != "" && parts[1] == echo.HeaderAuthorization {
|
|
// backwards compatibility for JWT and KeyAuth:
|
|
// * we only apply this fix to Authorization as header we use and uses prefixes like "Bearer <token-value>" etc
|
|
// * previously header extractor assumed that auth-scheme/prefix had a space as suffix we need to retain that
|
|
// behaviour for default values and Authorization header.
|
|
prefix = authScheme
|
|
if !strings.HasSuffix(prefix, " ") {
|
|
prefix += " "
|
|
}
|
|
}
|
|
extractors = append(extractors, valuesFromHeader(parts[1], prefix))
|
|
}
|
|
}
|
|
return extractors, nil
|
|
}
|
|
|
|
// valuesFromHeader returns a functions that extracts values from the request header.
|
|
// valuePrefix is parameter to remove first part (prefix) of the extracted value. This is useful if header value has static
|
|
// prefix like `Authorization: <auth-scheme> <authorisation-parameters>` where part that we want to remove is `<auth-scheme> `
|
|
// note the space at the end. In case of basic authentication `Authorization: Basic <credentials>` prefix we want to remove
|
|
// is `Basic `. In case of JWT tokens `Authorization: Bearer <token>` prefix is `Bearer `.
|
|
// If prefix is left empty the whole value is returned.
|
|
func valuesFromHeader(header string, valuePrefix string) ValuesExtractor {
|
|
prefixLen := len(valuePrefix)
|
|
// standard library parses http.Request header keys in canonical form but we may provide something else so fix this
|
|
header = textproto.CanonicalMIMEHeaderKey(header)
|
|
return func(c echo.Context) ([]string, error) {
|
|
values := c.Request().Header.Values(header)
|
|
if len(values) == 0 {
|
|
return nil, errHeaderExtractorValueMissing
|
|
}
|
|
|
|
result := make([]string, 0)
|
|
for i, value := range values {
|
|
if prefixLen == 0 {
|
|
result = append(result, value)
|
|
if i >= extractorLimit-1 {
|
|
break
|
|
}
|
|
continue
|
|
}
|
|
if len(value) > prefixLen && strings.EqualFold(value[:prefixLen], valuePrefix) {
|
|
result = append(result, value[prefixLen:])
|
|
if i >= extractorLimit-1 {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
|
|
if len(result) == 0 {
|
|
if prefixLen > 0 {
|
|
return nil, errHeaderExtractorValueInvalid
|
|
}
|
|
return nil, errHeaderExtractorValueMissing
|
|
}
|
|
return result, nil
|
|
}
|
|
}
|
|
|
|
// valuesFromQuery returns a function that extracts values from the query string.
|
|
func valuesFromQuery(param string) ValuesExtractor {
|
|
return func(c echo.Context) ([]string, error) {
|
|
result := c.QueryParams()[param]
|
|
if len(result) == 0 {
|
|
return nil, errQueryExtractorValueMissing
|
|
} else if len(result) > extractorLimit-1 {
|
|
result = result[:extractorLimit]
|
|
}
|
|
return result, nil
|
|
}
|
|
}
|
|
|
|
// valuesFromParam returns a function that extracts values from the url param string.
|
|
func valuesFromParam(param string) ValuesExtractor {
|
|
return func(c echo.Context) ([]string, error) {
|
|
result := make([]string, 0)
|
|
paramVales := c.ParamValues()
|
|
for i, p := range c.ParamNames() {
|
|
if param == p {
|
|
result = append(result, paramVales[i])
|
|
if i >= extractorLimit-1 {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if len(result) == 0 {
|
|
return nil, errParamExtractorValueMissing
|
|
}
|
|
return result, nil
|
|
}
|
|
}
|
|
|
|
// valuesFromCookie returns a function that extracts values from the named cookie.
|
|
func valuesFromCookie(name string) ValuesExtractor {
|
|
return func(c echo.Context) ([]string, error) {
|
|
cookies := c.Cookies()
|
|
if len(cookies) == 0 {
|
|
return nil, errCookieExtractorValueMissing
|
|
}
|
|
|
|
result := make([]string, 0)
|
|
for i, cookie := range cookies {
|
|
if name == cookie.Name {
|
|
result = append(result, cookie.Value)
|
|
if i >= extractorLimit-1 {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if len(result) == 0 {
|
|
return nil, errCookieExtractorValueMissing
|
|
}
|
|
return result, nil
|
|
}
|
|
}
|
|
|
|
// valuesFromForm returns a function that extracts values from the form field.
|
|
func valuesFromForm(name string) ValuesExtractor {
|
|
return func(c echo.Context) ([]string, error) {
|
|
if parseErr := c.Request().ParseForm(); parseErr != nil {
|
|
return nil, fmt.Errorf("valuesFromForm parse form failed: %w", parseErr)
|
|
}
|
|
values := c.Request().Form[name]
|
|
if len(values) == 0 {
|
|
return nil, errFormExtractorValueMissing
|
|
}
|
|
if len(values) > extractorLimit-1 {
|
|
values = values[:extractorLimit]
|
|
}
|
|
result := append([]string{}, values...)
|
|
return result, nil
|
|
}
|
|
}
|