package securecookie
import "strings"
// Error is the interface of all errors returned by functions in this library.
type Error interface {
error
// IsUsage returns true for errors indicating the client code probably
// uses this library incorrectly. For example, the client may have
// failed to provide a valid hash key, or may have failed to configure
// the Serializer adequately for encoding value.
IsUsage() bool
// IsDecode returns true for errors indicating that a cookie could not
// be decoded and validated. Since cookies are usually untrusted
// user-provided input, errors of this type should be expected.
// Usually, the proper action is simply to reject the request.
IsDecode() bool
// IsInternal returns true for unexpected errors occurring in the
// securecookie implementation.
IsInternal() bool
// Cause, if it returns a non-nil value, indicates that this error was
// propagated from some underlying library. If this method returns nil,
// this error was raised directly by this library.
//
// Cause is provided principally for debugging/logging purposes; it is
// rare that application logic should perform meaningfully different
// logic based on Cause. See, for example, the caveats described on
// (MultiError).Cause().
Cause() error
}
// errorType is a bitmask giving the error type(s) of an cookieError value.
type errorType int
const (
usageError = errorType(1 << iota)
decodeError
internalError
)
type cookieError struct {
typ errorType
msg string
cause error
}
func (e cookieError) IsUsage() bool { return (e.typ & usageError) != 0 }
func (e cookieError) IsDecode() bool { return (e.typ & decodeError) != 0 }
func (e cookieError) IsInternal() bool { return (e.typ & internalError) != 0 }
func (e cookieError) Cause() error { return e.cause }
func (e cookieError) Error() string {
parts := []string{"securecookie: "}
if e.msg == "" {
parts = append(parts, "error")
} else {
parts = append(parts, e.msg)
}
if c := e.Cause(); c != nil {
parts = append(parts, " - caused by: ", c.Error())
}
return strings.Join(parts, "")
}
var (
errGeneratingIV = cookieError{typ: internalError, msg: "failed to generate random iv"}
errNoCodecs = cookieError{typ: usageError, msg: "no codecs provided"}
errInvalidKey = cookieError{typ: usageError, msg: "no key was provided"}
errHashKeyNotSet = cookieError{typ: usageError, msg: "hash key is not set"}
errBlockKeyNotSet = cookieError{typ: usageError, msg: "block key is not set"}
errEncodedValueTooLong = cookieError{typ: usageError, msg: "the value is too long"}
errValueToDecodeTooLong = cookieError{typ: decodeError, msg: "the value is too long"}
errTimestampInvalid = cookieError{typ: decodeError, msg: "invalid timestamp"}
errTimestampTooNew = cookieError{typ: decodeError, msg: "timestamp is too new"}
errTimestampExpired = cookieError{typ: decodeError, msg: "expired timestamp"}
errDecryptionFailed = cookieError{typ: decodeError, msg: "the value could not be decrypted"}
errValueNotByte = cookieError{typ: decodeError, msg: "value not a []byte."}
// ErrMacInvalid indicates that cookie decoding failed because the HMAC
// could not be extracted and verified. Direct use of this error
// variable is deprecated; it is public only for legacy compatibility,
// and may be privatized in the future, as it is rarely useful to
// distinguish between this error and other Error implementations.
ErrMacInvalid = cookieError{typ: decodeError, msg: "the value is not valid"}
)
