Turn down passwords past 256 bytes unchecked

SHA-crypt hashes the password in most of its rounds, so the 4 KB that
cgit's POST limit lets through cost about fifteen ordinary logins per
anonymous attempt.

1 file changed, 22 insertions, 0 deletions

diff --git a/tests/extensions/test-auth.lua b/tests/extensions/test-auth.luaindex 5d3541c..97638bd 100644--- a/tests/extensions/test-auth.lua+++ b/tests/extensions/test-auth.lua@@ -278,6 +278,28 @@ out, ret = run_action("authenticate-post", { }) h.contains("an unknown user is told nothing different", out, "Set-Cookie: cgitauth=; ") +-- crypt's work grows with the password, so one past the cap is turned down+-- before crypt sees it.+local unistd = require("posix.unistd")+local real_crypt = unistd.crypt+local crypt_calls = 0+unistd.crypt = function(...)+	crypt_calls = crypt_calls + 1+	return real_crypt(...)+end+out, ret = run_action("authenticate-post", {+	method = "POST",+	body = "username=Alice&password=" .. string.rep("a", 257) .. "&redirect=" .. url_encode(way_back),+})+h.contains("an overlong password is turned down", out, "Set-Cookie: cgitauth=; ")+h.equals("without spending crypt on it", crypt_calls, 0)+out, ret = run_action("authenticate-post", {+	method = "POST",+	body = "username=Alice&password=" .. string.rep("a", 256) .. "&redirect=" .. url_encode(way_back),+})+h.equals("a password at the cap is still checked", crypt_calls, 1)+unistd.crypt = real_crypt+ out, ret = run_action("authenticate-post", { 	method = "POST", 	body = "username=Alice&password=" .. url_encode(password),
diff --git a/tests/extensions/test-auth.lua b/tests/extensions/test-auth.lua
index 5d3541c..97638bd 100644
--- a/tests/extensions/test-auth.lua
+++ b/tests/extensions/test-auth.lua
@@ -278,6 +278,28 @@ out, ret = run_action("authenticate-post", {
 })
 h.contains("an unknown user is told nothing different", out, "Set-Cookie: cgitauth=; ")
 
+-- crypt's work grows with the password, so one past the cap is turned down
+-- before crypt sees it.
+local unistd = require("posix.unistd")
+local real_crypt = unistd.crypt
+local crypt_calls = 0
+unistd.crypt = function(...)
+	crypt_calls = crypt_calls + 1
+	return real_crypt(...)
+end
+out, ret = run_action("authenticate-post", {
+	method = "POST",
+	body = "username=Alice&password=" .. string.rep("a", 257) .. "&redirect=" .. url_encode(way_back),
+})
+h.contains("an overlong password is turned down", out, "Set-Cookie: cgitauth=; ")
+h.equals("without spending crypt on it", crypt_calls, 0)
+out, ret = run_action("authenticate-post", {
+	method = "POST",
+	body = "username=Alice&password=" .. string.rep("a", 256) .. "&redirect=" .. url_encode(way_back),
+})
+h.equals("a password at the cap is still checked", crypt_calls, 1)
+unistd.crypt = real_crypt
+
 out, ret = run_action("authenticate-post", {
 	method = "POST",
 	body = "username=Alice&password=" .. url_encode(password),