🏷️ Created ClientID domain

internal/domain/client_id.go

@@ -0,0 +1,156 @@
+package domain
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	http "github.com/valyala/fasthttp"
+	"golang.org/x/xerrors"
+	"inet.af/netaddr"
+)
+
+// ClientID is a URL client identifier.
+type ClientID struct {
+	cid   *http.URI
+	valid bool
+}
+
+//nolint: gochecknoglobals
+var (
+	localhostIPv4 = netaddr.MustParseIP("127.0.0.1")
+	localhostIPv6 = netaddr.MustParseIP("::1")
+)
+
+func NewClientID(raw string) (*ClientID, error) {
+	cid := http.AcquireURI()
+	if err := cid.Parse(nil, []byte(raw)); err != nil {
+		return nil, Error{
+			Code:        "invalid_request",
+			Description: err.Error(),
+			URI:         "https://indieauth.net/source/#client-identifier",
+			Frame:       xerrors.Caller(1),
+		}
+	}
+
+	scheme := string(cid.Scheme())
+	if scheme != "http" && scheme != "https" {
+		return nil, Error{
+			Code:        "invalid_request",
+			Description: "client identifier URL MUST have either an https or http scheme",
+			URI:         "https://indieauth.net/source/#client-identifier",
+			Frame:       xerrors.Caller(1),
+		}
+	}
+
+	path := string(cid.PathOriginal())
+	if path == "" || strings.Contains(path, "/.") || strings.Contains(path, "/..") {
+		return nil, Error{
+			Code: "invalid_request",
+			Description: "client identifier URL MUST contain a path component and MUST NOT contain " +
+				"single-dot or double-dot path segments",
+			URI:   "https://indieauth.net/source/#client-identifier",
+			Frame: xerrors.Caller(1),
+		}
+	}
+
+	if cid.Hash() != nil {
+		return nil, Error{
+			Code:        "invalid_request",
+			Description: "client identifier URL MUST NOT contain a fragment component",
+			URI:         "https://indieauth.net/source/#client-identifier",
+			Frame:       xerrors.Caller(1),
+		}
+	}
+
+	if cid.Username() != nil || cid.Password() != nil {
+		return nil, Error{
+			Code:        "invalid_request",
+			Description: "client identifier URL MUST NOT contain a username or password component",
+			URI:         "https://indieauth.net/source/#client-identifier",
+			Frame:       xerrors.Caller(1),
+		}
+	}
+
+	domain := string(cid.Host())
+	if domain == "" {
+		return nil, Error{
+			Code:        "invalid_request",
+			Description: "client host name MUST be domain name or a loopback interface",
+			URI:         "https://indieauth.net/source/#client-identifier",
+			Frame:       xerrors.Caller(1),
+		}
+	}
+
+	ip, err := netaddr.ParseIP(domain)
+	if err != nil {
+		ipPort, err := netaddr.ParseIPPort(domain)
+		if err != nil {
+			return &ClientID{cid: cid}, nil
+		}
+
+		ip = ipPort.IP()
+	}
+
+	if !ip.IsLoopback() && ip.Compare(localhostIPv4) != 0 && ip.Compare(localhostIPv6) != 0 {
+		return nil, Error{
+			Code: "invalid_request",
+			Description: "client identifier URL MUST NOT be IPv4 or IPv6 addresses except for IPv4 " +
+				"127.0.0.1 or IPv6 [::1]",
+			URI:   "https://indieauth.net/source/#client-identifier",
+			Frame: xerrors.Caller(1),
+		}
+	}
+
+	return &ClientID{cid: cid}, nil
+}
+
+// TestClientID returns a valid random generated ClientID for tests.
+func TestClientID(tb testing.TB) *ClientID {
+	tb.Helper()
+
+	cid, err := NewClientID("https://app.example.com/")
+	require.NoError(tb, err)
+
+	return cid
+}
+
+// UnmarshalForm implements a custom form.Unmarshaler.
+func (cid *ClientID) UnmarshalForm(v []byte) error {
+	clientId, err := NewClientID(string(v))
+	if err != nil {
+		return fmt.Errorf("UnmarshalForm: %w", err)
+	}
+	defer http.ReleaseURI(clientId.cid) //nolint: wsl
+
+	clientId.cid.CopyTo(cid.cid)
+
+	return nil
+}
+
+// URI returns copy of parsed *fasthttp.URI.
+// This copy MUST be released via fasthttp.ReleaseURI.
+func (cid *ClientID) URI() *http.URI {
+	u := http.AcquireURI()
+	cid.cid.CopyTo(u)
+
+	return u
+}
+
+func (cid *ClientID) URL() *url.URL {
+	return &url.URL{
+		Scheme:   string(cid.cid.Scheme()),
+		Host:     string(cid.cid.Host()),
+		Path:     string(cid.cid.Path()),
+		RawPath:  string(cid.cid.PathOriginal()),
+		RawQuery: string(cid.cid.QueryString()),
+		Fragment: string(cid.cid.Hash()),
+	}
+}
+
+// String returns string representation of client ID.
+func (cid *ClientID) String() string {
+	return cid.cid.String()
+}

internal/domain/client_id_test.go

@@ -0,0 +1,79 @@
+package domain_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"source.toby3d.me/website/oauth/internal/domain"
+)
+
+//nolint: funlen
+func TestClientID(t *testing.T) {
+	t.Parallel()
+
+	for _, testCase := range []struct {
+		name    string
+		input   string
+		isValid bool
+	}{{
+		name:    "valid",
+		input:   "https://example.com/",
+		isValid: true,
+	}, {
+		name:    "valid with path",
+		input:   "https://example.com/username",
+		isValid: true,
+	}, {
+		name:    "valid with query",
+		input:   "https://example.com/users?id=100",
+		isValid: true,
+	}, {
+		name:    "valid with port",
+		input:   "https://example.com:8443/",
+		isValid: true,
+	}, {
+		name:    "valid loopback",
+		input:   "https://127.0.0.1:8443/",
+		isValid: true,
+	}, {
+		name:    "missing scheme",
+		input:   "example.com",
+		isValid: false,
+	}, {
+		name:    "invalid scheme",
+		input:   "mailto:user@example.com",
+		isValid: false,
+	}, {
+		name:    "contains a double-dot path segment",
+		input:   "https://example.com/foo/../bar",
+		isValid: false,
+	}, {
+		name:    "contains a fragment",
+		input:   "https://example.com/#me",
+		isValid: false,
+	}, {
+		name:    "contains a username and password",
+		input:   "https://user:pass@example.com/",
+		isValid: false,
+	}, {
+		name:    "host is an IP address",
+		input:   "https://172.28.92.51/",
+		isValid: false,
+	}} {
+		testCase := testCase
+
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Parallel()
+
+			result, err := domain.NewClientID(testCase.input)
+			if testCase.isValid {
+				require.NoError(t, err)
+				assert.Equal(t, testCase.input, result.String())
+			} else {
+				assert.Error(t, err)
+			}
+		})
+	}
+}