1 file changed, 25 insertions, 0 deletions

diff --git a/tests/extensions/test-auth.lua b/tests/extensions/test-auth.luaindex 18017ff..6bd588d 100644--- a/tests/extensions/test-auth.lua+++ b/tests/extensions/test-auth.lua@@ -231,6 +231,8 @@ h.check("and in linear time", os.clock() - started < 0.5)  h.check("equal strings compare equal", constant_equals("abc", "abc")) h.check("differing strings do not", not constant_equals("abc", "abd"))+h.check("nor do strings whose byte differences cancel out",+	not constant_equals("ab", "ba") and not constant_equals("ac", "bb")) h.check("differing lengths do not", not constant_equals("a", "ab")) h.check("non strings do not", not constant_equals(nil, "a")) @@ -468,6 +470,29 @@ h.equals("and grants a session that verifies", granted and validate_value("usern local expires = session_expiry(granted) h.check("which expires a week after the login", 	expires and expires >= before + 604800 and expires <= os.time() + 604800, tostring(expires))++-- A plain == at either comparison would leave every check above passing+-- while timing told a visitor how much of a guess was right.+local real_constant_equals = constant_equals+local compared = {}+constant_equals = function(a, b)+	compared[#compared + 1] = { a, b }+	return real_constant_equals(a, b)+end+local function was_compared(value)+	for _, pair in ipairs(compared) do+		if pair[1] == value or pair[2] == value then+			return true+		end+	end+	return false+end+visit("secret-repo", session)+h.check("a visit compares the signature in constant time", was_compared(session:match("[^|]+$")))+compared = {}+login("Alice", password, way_back)+h.check("and a login the password's hash", was_compared(stored_hash))+constant_equals = real_constant_equals h.equals("and logs nothing", h.error_log(), "")  out = login("Alice", "wrong", way_back)
diff --git a/tests/extensions/test-auth.lua b/tests/extensions/test-auth.lua
index 18017ff..6bd588d 100644
--- a/tests/extensions/test-auth.lua
+++ b/tests/extensions/test-auth.lua
@@ -231,6 +231,8 @@ h.check("and in linear time", os.clock() - started < 0.5)
 
 h.check("equal strings compare equal", constant_equals("abc", "abc"))
 h.check("differing strings do not", not constant_equals("abc", "abd"))
+h.check("nor do strings whose byte differences cancel out",
+	not constant_equals("ab", "ba") and not constant_equals("ac", "bb"))
 h.check("differing lengths do not", not constant_equals("a", "ab"))
 h.check("non strings do not", not constant_equals(nil, "a"))
 
@@ -468,6 +470,29 @@ h.equals("and grants a session that verifies", granted and validate_value("usern
 local expires = session_expiry(granted)
 h.check("which expires a week after the login",
 	expires and expires >= before + 604800 and expires <= os.time() + 604800, tostring(expires))
+
+-- A plain == at either comparison would leave every check above passing
+-- while timing told a visitor how much of a guess was right.
+local real_constant_equals = constant_equals
+local compared = {}
+constant_equals = function(a, b)
+	compared[#compared + 1] = { a, b }
+	return real_constant_equals(a, b)
+end
+local function was_compared(value)
+	for _, pair in ipairs(compared) do
+		if pair[1] == value or pair[2] == value then
+			return true
+		end
+	end
+	return false
+end
+visit("secret-repo", session)
+h.check("a visit compares the signature in constant time", was_compared(session:match("[^|]+$")))
+compared = {}
+login("Alice", password, way_back)
+h.check("and a login the password's hash", was_compared(stored_hash))
+constant_equals = real_constant_equals
 h.equals("and logs nothing", h.error_log(), "")
 
 out = login("Alice", "wrong", way_back)