Initial commit

.gitignore

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+*~
+

init.lua

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+-- name_restrictions mod by ShadowNinja
+-- License: WTFPL
+
+---------------------
+-- Simple matching --
+---------------------
+
+local disallowed = {
+	["^guest[0-9]+"] = "Guest accounts are disallowed on this server.  "..
+	                   "Please choose a proper username and try again.",
+	["adm[1il]n"]    = "Misleading nickname.",
+	["[0o]wn[e3]r"]  = "Misleading nickname.",
+	["^[0-9]+$"]     = "All-numeric usernames are disallowed on this server.",
+}
+
+minetest.register_on_prejoinplayer(function(name, ip)
+	local lname = name:lower()
+	for re, reason in pairs(disallowed) do
+		if lname:find(re) then
+			return reason
+		end
+	end
+end)
+
+
+------------------------
+-- Case-insensitivity --
+------------------------
+
+minetest.register_on_prejoinplayer(function(name, ip)
+	local lname = name:lower()
+	for iname, data in pairs(minetest.auth_table) do
+		if iname:lower() == lname and iname ~= name then
+			return "Sorry, someone else is already using this"
+				.." name.  Please pick another name."
+				.."  Annother posibility is that you used the"
+				.." wrong case for your name."
+		end
+	end
+end)
+
+-- Compatability, for old servers with conflicting players
+minetest.register_chatcommand("choosecase", {
+	description = "Choose the casing that a player name should have.",
+	params = "<name>",
+	privs = {server=true},
+	func = function(name, params)
+		local lname = params:lower()
+		local worldpath = minetest.get_worldpath()
+		for iname, data in pairs(minetest.auth_table) do
+			if iname:lower() == lname and iname ~= params then
+				minetest.auth_table[iname] = nil
+				assert(not iname:find("[/\\]"))
+				os.remove(worldpath.."/players/"..iname)
+			end
+		end
+		return true, "Done."
+	end,
+})
+
+
+------------------------
+-- Anti-impersonation --
+------------------------
+-- Prevents names that are too similar to annother player's name.
+
+local similar_chars = {
+	-- Only A-Z, a-z, 1-9, dash, and underscore are allowed in playernames
+	"A4",
+	"B8"
+	"COco0",
+	"Ee3",
+	"Gg69",
+	"ILil1",
+	"S5",
+	"Tt7",
+	"Zz2",
+}
+
+-- Map of characters to a regex of similar characters
+local char_map = {}
+for _, str in pairs(similar_chars) do
+	for c in str:gmatch(".") do
+		if not char_map[c] then
+			char_map[c] = str
+		else
+			char_map[c] = char_map[c] .. str
+		end
+	end
+end
+
+for c, str in pairs(char_map) do
+	char_map[c] = "[" .. char_map[c] .."]"
+end
+
+-- Characters to match for, containing all characters
+local all_chars = "["
+for _, str in pairs(similar_chars) do
+	all_chars = all_chars .. str
+end
+all_chars = all_chars .. "]"
+
+
+minetest.register_on_prejoinplayer(function(name, ip)
+	local re = name:gsub(all_chars, char_map)
+	re = "^[_-]*" .. re .. "[_-]*$"
+	for authName, _ in pairs(minetest.auth_table) do
+		if authName ~= name and authName:match(re) then
+			return "Your name is too similar to annother player's name."
+		end
+	end
+end)
+
+