1package awsrulesfn
 2
 3import (
 4	"net"
 5	"strings"
 6
 7	smithyhttp "github.com/aws/smithy-go/transport/http"
 8)
 9
10// IsVirtualHostableS3Bucket returns if the input is a DNS compatible bucket
11// name and can be used with Amazon S3 virtual hosted style addressing. Similar
12// to [rulesfn.IsValidHostLabel] with the added restriction that the length of label
13// must be [3:63] characters long, all lowercase, and not formatted as an IP
14// address.
15func IsVirtualHostableS3Bucket(input string, allowSubDomains bool) bool {
16	// input should not be formatted as an IP address
17	// NOTE: this will technically trip up on IPv6 hosts with zone IDs, but
18	// validation further down will catch that anyway (it's guaranteed to have
19	// unfriendly characters % and : if that's the case)
20	if net.ParseIP(input) != nil {
21		return false
22	}
23
24	var labels []string
25	if allowSubDomains {
26		labels = strings.Split(input, ".")
27	} else {
28		labels = []string{input}
29	}
30
31	for _, label := range labels {
32		// validate special length constraints
33		if l := len(label); l < 3 || l > 63 {
34			return false
35		}
36
37		// Validate no capital letters
38		for _, r := range label {
39			if r >= 'A' && r <= 'Z' {
40				return false
41			}
42		}
43
44		// Validate valid host label
45		if !smithyhttp.ValidHostLabel(label) {
46			return false
47		}
48	}
49
50	return true
51}