From 7c7f0fdae3470c7cb6c3aeb3972b9daede7f866e Mon Sep 17 00:00:00 2001
From: Ashish Amarnath <ashish.amarnath@broadcom.com>
Date: Mon, 29 Jul 2024 14:05:07 -0700
Subject: [PATCH] make host name parsing case-insensitive

Signed-off-by: Ashish Amarnath <ashish.amarnath@broadcom.com>

Co-authored-by: Ryan Richard <richardry@vmware.com>
---
 internal/endpointaddr/endpointaddr.go      |  3 +-
 internal/endpointaddr/endpointaddr_test.go | 33 ++++++++++++++++------
 2 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/internal/endpointaddr/endpointaddr.go b/internal/endpointaddr/endpointaddr.go
index c54ca421e..c2766daea 100644
--- a/internal/endpointaddr/endpointaddr.go
+++ b/internal/endpointaddr/endpointaddr.go
@@ -65,7 +65,8 @@ func Parse(endpoint string, defaultPort uint16) (HostPort, error) {
 	// Check if the host part is a IPv4 or IPv6 address or a valid hostname according to RFC 1123.
 	switch {
 	case len(validation.IsValidIP(field.NewPath("UNKNOWN_PATH"), host)) == 0:
-	case len(validation.IsDNS1123Subdomain(host)) == 0:
+	// the host name should be case-insensitive.
+	case len(validation.IsDNS1123Subdomain(strings.ToLower(host))) == 0:
 	default:
 		return HostPort{}, fmt.Errorf("host %q is not a valid hostname or IP address", host)
 	}
diff --git a/internal/endpointaddr/endpointaddr_test.go b/internal/endpointaddr/endpointaddr_test.go
index 1d560629d..13e203e84 100644
--- a/internal/endpointaddr/endpointaddr_test.go
+++ b/internal/endpointaddr/endpointaddr_test.go
@@ -161,18 +161,25 @@ func TestParse(t *testing.T) {
 			defaultPort: 443,
 			expectErr:   `host "___.example.com" is not a valid hostname or IP address`,
 		},
-		{
-			name:        "invalid host with uppercase",
-			input:       "HOST.EXAMPLE.COM",
-			defaultPort: 443,
-			expectErr:   `host "HOST.EXAMPLE.COM" is not a valid hostname or IP address`,
-		},
 		{
 			name:        "invalid host with extra port",
 			input:       "host.example.com:port1:port2",
 			defaultPort: 443,
 			expectErr:   `host "host.example.com:port1:port2" is not a valid hostname or IP address`,
 		},
+		{
+			name:           "hostname with upper case letters should be valid",
+			input:          "HoSt.EXamplE.cOM",
+			defaultPort:    443,
+			expect:         HostPort{Host: "HoSt.EXamplE.cOM", Port: 443},
+			expectEndpoint: "HoSt.EXamplE.cOM:443",
+		},
+		{
+			name:        "unicode chars are disallowed in host names",
+			input:       "Hello.世界🙂.com",
+			defaultPort: 443,
+			expectErr:   `host "Hello.世界🙂.com" is not a valid hostname or IP address`,
+		},
 	} {
 		t.Run(tt.name, func(t *testing.T) {
 			got, err := Parse(tt.input, tt.defaultPort)
@@ -292,11 +299,19 @@ func TestParseFromURL(t *testing.T) {
 			defaultPort: 443,
 			expectErr:   `host "___.example.com" is not a valid hostname or IP address`,
 		},
+
 		{
-			name:        "invalid host with uppercase",
-			input:       "http://HOST.EXAMPLE.COM",
+			name:           "hostname with upper case letters should be valid",
+			input:          "https://HoSt.EXamplE.cOM",
+			defaultPort:    443,
+			expect:         HostPort{Host: "HoSt.EXamplE.cOM", Port: 443},
+			expectEndpoint: "HoSt.EXamplE.cOM:443",
+		},
+		{
+			name:        "unicode chars are disallowed in host names",
+			input:       "https://Hello.世界🙂.com",
 			defaultPort: 443,
-			expectErr:   `host "HOST.EXAMPLE.COM" is not a valid hostname or IP address`,
+			expectErr:   `host "Hello.世界🙂.com" is not a valid hostname or IP address`,
 		},
 		// new tests for new functionality
 		{