hCaptcha Support (#12594)

* Initial work on hCaptcha

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Use module

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Format

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* At least return and debug log a captcha error

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Pass context to hCaptcha

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Add context to recaptcha

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* fix lint

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Finish hcaptcha

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Update example config

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Apply error fix for recaptcha

Signed-off-by: jolheiser <john.olheiser@gmail.com>

* Change recaptcha ChallengeTS to string

Signed-off-by: jolheiser <john.olheiser@gmail.com>

Co-authored-by: Andrew Thornton <art27@cantab.net>

vendor/go.jolheiser.com/hcaptcha/error.go

@@ -0,0 +1,41 @@
+package hcaptcha
+
+const (
+	ErrMissingInputSecret           ErrorCode = "missing-input-secret"
+	ErrInvalidInputSecret           ErrorCode = "invalid-input-secret"
+	ErrMissingInputResponse         ErrorCode = "missing-input-response"
+	ErrInvalidInputResponse         ErrorCode = "invalid-input-response"
+	ErrBadRequest                   ErrorCode = "bad-request"
+	ErrInvalidOrAlreadySeenResponse ErrorCode = "invalid-or-already-seen-response"
+	ErrSitekeySecretMismatch        ErrorCode = "sitekey-secret-mismatch"
+)
+
+// ErrorCode is any possible error from hCaptcha
+type ErrorCode string
+
+// String fulfills the Stringer interface
+func (err ErrorCode) String() string {
+	switch err {
+	case ErrMissingInputSecret:
+		return "Your secret key is missing."
+	case ErrInvalidInputSecret:
+		return "Your secret key is invalid or malformed."
+	case ErrMissingInputResponse:
+		return "The response parameter (verification token) is missing."
+	case ErrInvalidInputResponse:
+		return "The response parameter (verification token) is invalid or malformed."
+	case ErrBadRequest:
+		return "The request is invalid or malformed."
+	case ErrInvalidOrAlreadySeenResponse:
+		return "The response parameter has already been checked, or has another issue."
+	case ErrSitekeySecretMismatch:
+		return "The sitekey is not registered with the provided secret."
+	default:
+		return ""
+	}
+}
+
+// Error fulfills the error interface
+func (err ErrorCode) Error() string {
+	return err.String()
+}