Update

vendor/github.com/aws/smithy-go/endpoints/private/rulesfn/uri.go

@@ -0,0 +1,130 @@
+package rulesfn
+
+import (
+	"fmt"
+	"net"
+	"net/url"
+	"strings"
+
+	smithyhttp "github.com/aws/smithy-go/transport/http"
+)
+
+// IsValidHostLabel returns if the input is a single valid [RFC 1123] host
+// label. If allowSubDomains is true, will allow validation to include nested
+// host labels. Returns false if the input is not a valid host label. If errors
+// occur they will be added to the provided [ErrorCollector].
+//
+// [RFC 1123]: https://www.ietf.org/rfc/rfc1123.txt
+func IsValidHostLabel(input string, allowSubDomains bool) bool {
+	var labels []string
+	if allowSubDomains {
+		labels = strings.Split(input, ".")
+	} else {
+		labels = []string{input}
+	}
+
+	for _, label := range labels {
+		if !smithyhttp.ValidHostLabel(label) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// ParseURL returns a [URL] if the provided string could be parsed. Returns nil
+// if the string could not be parsed. Any parsing error will be added to the
+// [ErrorCollector].
+//
+// If the input URL string contains an IP6 address with a zone index. The
+// returned [builtin.URL.Authority] value will contain the percent escaped (%)
+// zone index separator.
+func ParseURL(input string) *URL {
+	u, err := url.Parse(input)
+	if err != nil {
+		return nil
+	}
+
+	if u.RawQuery != "" {
+		return nil
+	}
+
+	if u.Scheme != "http" && u.Scheme != "https" {
+		return nil
+	}
+
+	normalizedPath := u.Path
+	if !strings.HasPrefix(normalizedPath, "/") {
+		normalizedPath = "/" + normalizedPath
+	}
+	if !strings.HasSuffix(normalizedPath, "/") {
+		normalizedPath = normalizedPath + "/"
+	}
+
+	// IP6 hosts may have zone indexes that need to be escaped to be valid in a
+	// URI. The Go URL parser will unescape the `%25` into `%`. This needs to
+	// be reverted since the returned URL will be used in string builders.
+	authority := strings.ReplaceAll(u.Host, "%", "%25")
+
+	return &URL{
+		Scheme:         u.Scheme,
+		Authority:      authority,
+		Path:           u.Path,
+		NormalizedPath: normalizedPath,
+		IsIp:           net.ParseIP(hostnameWithoutZone(u)) != nil,
+	}
+}
+
+// URL provides the structure describing the parts of a parsed URL returned by
+// [ParseURL].
+type URL struct {
+	Scheme         string // https://www.rfc-editor.org/rfc/rfc3986#section-3.1
+	Authority      string // https://www.rfc-editor.org/rfc/rfc3986#section-3.2
+	Path           string // https://www.rfc-editor.org/rfc/rfc3986#section-3.3
+	NormalizedPath string // https://www.rfc-editor.org/rfc/rfc3986#section-6.2.3
+	IsIp           bool
+}
+
+// URIEncode returns an percent-encoded [RFC3986 section 2.1] version of the
+// input string.
+//
+// [RFC3986 section 2.1]: https://www.rfc-editor.org/rfc/rfc3986#section-2.1
+func URIEncode(input string) string {
+	var output strings.Builder
+	for _, c := range []byte(input) {
+		if validPercentEncodedChar(c) {
+			output.WriteByte(c)
+			continue
+		}
+
+		fmt.Fprintf(&output, "%%%X", c)
+	}
+
+	return output.String()
+}
+
+func validPercentEncodedChar(c byte) bool {
+	return (c >= 'a' && c <= 'z') ||
+		(c >= 'A' && c <= 'Z') ||
+		(c >= '0' && c <= '9') ||
+		c == '-' || c == '_' || c == '.' || c == '~'
+}
+
+// hostname implements u.Hostname() but strips the ipv6 zone ID (if present)
+// such that net.ParseIP can still recognize IPv6 addresses with zone IDs.
+//
+// FUTURE(10/2023): netip.ParseAddr handles this natively but we can't take
+// that package as a dependency yet due to our min go version (1.15, netip
+// starts in 1.18).  When we align with go runtime deprecation policy in
+// 10/2023, we can remove this.
+func hostnameWithoutZone(u *url.URL) string {
+	full := u.Hostname()
+
+	// this more or less mimics the internals of net/ (see unexported
+	// splitHostZone in that source) but throws the zone away because we don't
+	// need it
+	if i := strings.LastIndex(full, "%"); i > -1 {
+		return full[:i]
+	}
+	return full
+}