diff --git a/rest_framework/authentication.py b/rest_framework/authentication.py
index 382abf158..4a4d0f8aa 100644
--- a/rest_framework/authentication.py
+++ b/rest_framework/authentication.py
@@ -65,13 +65,10 @@ class BasicAuthentication(BaseAuthentication):
 
         if not auth or auth[0].lower() != b'basic':
             return None
-
-        if len(auth) == 1:
+        
+        if len(auth) != 2:
             msg = _('Invalid basic header. No credentials provided.')
             raise exceptions.AuthenticationFailed(msg)
-        elif len(auth) > 2:
-            msg = _('Invalid basic header. Credentials string should not contain spaces.')
-            raise exceptions.AuthenticationFailed(msg)
 
         try:
             try:
@@ -180,12 +177,9 @@ class TokenAuthentication(BaseAuthentication):
         if not auth or auth[0].lower() != self.keyword.lower().encode():
             return None
 
-        if len(auth) == 1:
+        if len(auth) != 2:
             msg = _('Invalid token header. No credentials provided.')
             raise exceptions.AuthenticationFailed(msg)
-        elif len(auth) > 2:
-            msg = _('Invalid token header. Token string should not contain spaces.')
-            raise exceptions.AuthenticationFailed(msg)
 
         try:
             token = auth[1].decode()