refactor: rename session cookie key

internal/ctx/cookies.go

@@ -1,24 +1,40 @@
 package ctx
 
 import (
+	"github.com/go-webauthn/webauthn/protocol"
 	"github.com/labstack/echo/v4"
 	"github.com/segmentio/ksuid"
 )
 
+// CookieKey is a type alias for string.
 type CookieKey string
 
 const (
+	// CookieKeySessionID is the key for the session ID cookie.
 	CookieKeySessionID CookieKey = "session.id"
+
+	// CookieKeySessionChal is the key for the session challenge cookie.
+	CookieKeySessionChal CookieKey = "session.chal"
+
+	// CookieKeySonrAddr is the key for the Sonr address cookie.
 	CookieKeySonrAddr CookieKey = "sonr.addr"
+
+	// CookieKeySonrDID is the key for the Sonr DID cookie.
 	CookieKeySonrDID CookieKey = "sonr.did"
+
+	// CookieKeyVaultCID is the key for the Vault CID cookie.
 	CookieKeyVaultCID CookieKey = "vault.cid"
+
+	// CookieKeyVaultSchema is the key for the Vault schema cookie.
 	CookieKeyVaultSchema CookieKey = "vault.schema"
 )
 
+// String returns the string representation of the CookieKey.
 func (c CookieKey) String() string {
 	return string(c)
 }
 
+// GetSessionID returns the session ID from the cookies.
 func GetSessionID(c echo.Context) string {
 	// Attempt to read the session ID from the "session" cookie
 	sessionID, err := ReadCookie(c, CookieKeySessionID)
@@ -28,3 +44,24 @@ func GetSessionID(c echo.Context) string {
 	}
 	return sessionID
 }
+
+// GetSessionChallenge returns the session challenge from the cookies.
+func GetSessionChallenge(c echo.Context) (*protocol.URLEncodedBase64, error) {
+	chal := new(protocol.URLEncodedBase64)
+	// Attempt to read the session challenge from the "session" cookie
+	sessionChal, err := ReadCookie(c, CookieKeySessionChal)
+	if err != nil {
+		// Generate a new challenge if the session cookie is missing or invalid
+		ch, errb := protocol.CreateChallenge()
+		if errb != nil {
+			return nil, err
+		}
+		WriteCookie(c, CookieKeySessionChal, ch.String())
+		return &ch, nil
+	}
+	err = chal.UnmarshalJSON([]byte(sessionChal))
+	if err != nil {
+		return nil, err
+	}
+	return chal, nil
+}