vendor/github.com/aws/aws-sdk-go/private/protocol/host.go

   1 package protocol
   2
   3 import (
   4         "strings"
   5
   6         "github.com/aws/aws-sdk-go/aws/request"
   7 )
   8
   9 // ValidateEndpointHostHandler is a request handler that will validate the
  10 // request endpoint's hosts is a valid RFC 3986 host.
  11 var ValidateEndpointHostHandler = request.NamedHandler{
  12         Name: "awssdk.protocol.ValidateEndpointHostHandler",
  13         Fn: func(r *request.Request) {
  14                 err := ValidateEndpointHost(r.Operation.Name, r.HTTPRequest.URL.Host)
  15                 if err != nil {
  16                         r.Error = err
  17                 }
  18         },
  19 }
  20
  21 // ValidateEndpointHost validates that the host string passed in is a valid RFC
  22 // 3986 host. Returns error if the host is not valid.
  23 func ValidateEndpointHost(opName, host string) error {
  24         paramErrs := request.ErrInvalidParams{Context: opName}
  25         labels := strings.Split(host, ".")
  26
  27         for i, label := range labels {
  28                 if i == len(labels)-1 && len(label) == 0 {
  29                         // Allow trailing dot for FQDN hosts.
  30                         continue
  31                 }
  32
  33                 if !ValidHostLabel(label) {
  34                         paramErrs.Add(request.NewErrParamFormat(
  35                                 "endpoint host label", "[a-zA-Z0-9-]{1,63}", label))
  36                 }
  37         }
  38
  39         if len(host) > 255 {
  40                 paramErrs.Add(request.NewErrParamMaxLen(
  41                         "endpoint host", 255, host,
  42                 ))
  43         }
  44
  45         if paramErrs.Len() > 0 {
  46                 return paramErrs
  47         }
  48         return nil
  49 }
  50
  51 // ValidHostLabel returns if the label is a valid RFC 3986 host label.
  52 func ValidHostLabel(label string) bool {
  53         if l := len(label); l == 0 || l > 63 {
  54                 return false
  55         }
  56         for _, r := range label {
  57                 switch {
  58                 case r >= '0' && r <= '9':
  59                 case r >= 'A' && r <= 'Z':
  60                 case r >= 'a' && r <= 'z':
  61                 case r == '-':
  62                 default:
  63                         return false
  64                 }
  65         }
  66
  67         return true
  68 }