2 files changed, 107 insertions, 0 deletions
diff --git a/runtime/lua/vim/_editor.lua b/runtime/lua/vim/_editor.lua
index 0013f38d89..ad4dc20efb 100644
--- a/runtime/lua/vim/_editor.lua
+++ b/runtime/lua/vim/_editor.lua
@@ -36,6 +36,7 @@ for k, v in pairs({
   ui = true,
   health = true,
   fs = true,
+  secure = true,
 }) do
   vim._submodules[k] = v
 end
diff --git a/runtime/lua/vim/secure.lua b/runtime/lua/vim/secure.lua
new file mode 100644
index 0000000000..341ff8df05
--- /dev/null
+++ b/runtime/lua/vim/secure.lua
@@ -0,0 +1,106 @@
+local M = {}
+
+--- Attempt to read the file at {path} prompting the user if the file should be
+--- trusted. The user's choice is persisted in a trust database at
+--- $XDG_STATE_HOME/nvim/trust.
+---
+---@param path (string) Path to a file to read.
+---
+---@return (string|nil) The contents of the given file if it exists and is
+---        trusted, or nil otherwise.
+function M.read(path)
+  vim.validate({ path = { path, 's' } })
+  local fullpath = vim.loop.fs_realpath(vim.fs.normalize(path))
+  if not fullpath then
+    return nil
+  end
+
+  local trust = {}
+  do
+    local f = io.open(vim.fn.stdpath('state') .. '/trust', 'r')
+    if f then
+      local contents = f:read('*a')
+      if contents then
+        for line in vim.gsplit(contents, '\n') do
+          local hash, file = string.match(line, '^(%S+) (.+)$')
+          if hash and file then
+            trust[file] = hash
+          end
+        end
+      end
+      f:close()
+    end
+  end
+
+  if trust[fullpath] == '!' then
+    -- File is denied
+    return nil
+  end
+
+  local contents
+  do
+    local f = io.open(fullpath, 'r')
+    if not f then
+      return nil
+    end
+    contents = f:read('*a')
+    f:close()
+  end
+
+  local hash = vim.fn.sha256(contents)
+  if trust[fullpath] == hash then
+    -- File already exists in trust database
+    return contents
+  end
+
+  -- File either does not exist in trust database or the hash does not match
+  local choice = vim.fn.confirm(
+    string.format('%s is not trusted.', fullpath),
+    '&ignore\n&view\n&deny\n&allow',
+    1
+  )
+
+  if choice == 0 or choice == 1 then
+    -- Cancelled or ignored
+    return nil
+  elseif choice == 2 then
+    -- View
+    vim.cmd('new')
+    local buf = vim.api.nvim_get_current_buf()
+    local lines = vim.split(string.gsub(contents, '\n$', ''), '\n')
+    vim.api.nvim_buf_set_lines(buf, 0, -1, false, lines)
+    vim.bo[buf].bufhidden = 'hide'
+    vim.bo[buf].buftype = 'nofile'
+    vim.bo[buf].swapfile = false
+    vim.bo[buf].modeline = false
+    vim.bo[buf].buflisted = false
+    vim.bo[buf].readonly = true
+    vim.bo[buf].modifiable = false
+    return nil
+  elseif choice == 3 then
+    -- Deny
+    trust[fullpath] = '!'
+    contents = nil
+  elseif choice == 4 then
+    -- Allow
+    trust[fullpath] = hash
+  end
+
+  do
+    local f, err = io.open(vim.fn.stdpath('state') .. '/trust', 'w')
+    if not f then
+      error(err)
+    end
+
+    local t = {}
+    for p, h in pairs(trust) do
+      t[#t + 1] = string.format('%s %s\n', h, p)
+    end
+    f:write(table.concat(t))
+    f:close()
+  end
+
+  return contents
+end
+
+return M