Login via OpenID-2.0 (#618)

vendor/github.com/yohcop/openid-go/normalizer.go

@@ -0,0 +1,64 @@
+package openid
+
+import (
+	"errors"
+	"net/url"
+	"strings"
+)
+
+func Normalize(id string) (string, error) {
+	id = strings.TrimSpace(id)
+	if len(id) == 0 {
+		return "", errors.New("No id provided")
+	}
+
+	// 7.2 from openID 2.0 spec.
+
+	//If the user's input starts with the "xri://" prefix, it MUST be
+	//stripped off, so that XRIs are used in the canonical form.
+	if strings.HasPrefix(id, "xri://") {
+		id = id[6:]
+		return id, errors.New("XRI identifiers not supported")
+	}
+
+	// If the first character of the resulting string is an XRI
+	// Global Context Symbol ("=", "@", "+", "$", "!") or "(", as
+	// defined in Section 2.2.1 of [XRI_Syntax_2.0], then the input
+	// SHOULD be treated as an XRI.
+	if b := id[0]; b == '=' || b == '@' || b == '+' || b == '$' || b == '!' {
+		return id, errors.New("XRI identifiers not supported")
+	}
+
+	// Otherwise, the input SHOULD be treated as an http URL; if it
+	// does not include a "http" or "https" scheme, the Identifier
+	// MUST be prefixed with the string "http://". If the URL
+	// contains a fragment part, it MUST be stripped off together
+	// with the fragment delimiter character "#". See Section 11.5.2 for
+	// more information.
+	if !strings.HasPrefix(id, "http://") && !strings.HasPrefix(id,
+		"https://") {
+		id = "http://" + id
+	}
+	if fragmentIndex := strings.Index(id, "#"); fragmentIndex != -1 {
+		id = id[0:fragmentIndex]
+	}
+	if u, err := url.ParseRequestURI(id); err != nil {
+		return "", err
+	} else {
+		if u.Host == "" {
+			return "", errors.New("Invalid address provided as id")
+		}
+		if u.Path == "" {
+			u.Path = "/"
+		}
+		id = u.String()
+	}
+
+	// URL Identifiers MUST then be further normalized by both
+	// following redirects when retrieving their content and finally
+	// applying the rules in Section 6 of [RFC3986] to the final
+	// destination URL. This final URL MUST be noted by the Relying
+	// Party as the Claimed Identifier and be used when requesting
+	// authentication.
+	return id, nil
+}