aes.lua: `s` passed to `_M.encrypt` appears to be table?

[odiferousmint]

I get the following error upon attempting to call encrypt.

site/lualib/resty/aes.lua:191: bad argument #4 to 'EVP_EncryptUpdate' (cannot convert 'table' to 'const unsigned char *')

The Lua script is nothing fancy:

local aes = require "resty.aes"
local cipher = aes:new("secretKey")
local encryptedData, err = cipher:encrypt(sessionData)
if not encryptedData then
  return err
end

If I shadow the s variable in _M.encrypt(self, s), e.g. by doing local s = "foo", then the error disappears, so it definitely is s that is the issue although I am not sure why s is a table to begin with.

[odiferousmint]

Never mind, I do not think you are supposed to encrypt the whole session data, but encrypt a specific key's value instead.