Panasonic Viera TV IP control

[admin]

Here's Python code converted to Lua:

Code:

require('encdec')
aes = require('user.aes')

iv = encdec.base64dec('mUQdS7/RyJTMsiojPz9i1Q==')
iv_vals = { iv:byte(1, -1) }
key_vals = {}

for i = 1, 16, 4 do
  key_vals[ i ] = bit.band(bit.bnot(iv_vals[ i + 3 ]), 0xFF)
  key_vals[ i + 1 ] = bit.band(bit.bnot(iv_vals[ i + 2 ]), 0xFF)
  key_vals[ i + 2 ] = bit.band(bit.bnot(iv_vals[ i + 1 ]), 0xFF)
  key_vals[ i + 3 ] = bit.band(bit.bnot(iv_vals[ i ]), 0xFF)
end

key = string.char(unpack(key_vals))
hmac_key_mask = lmcore.hextostr('15C95AC2B08AA7EB4E228F811E34D04FA54BA7DCAC9879FA8ACDA3FC244F3854', true)
hmac_key_mask_vals = { hmac_key_mask:byte(1, -1) }
hmac_vals = {}

for i = 1, 32, 4 do
  hmac_vals[ i ] = bit.bxor(hmac_key_mask_vals[ i ], iv_vals[ bit.band(i + 1, 0xF) + 1 ])
  hmac_vals[ i + 1 ] = bit.bxor(hmac_key_mask_vals[ i + 1 ], iv_vals[ bit.band(i + 2, 0xF) + 1 ])
  hmac_vals[ i + 2 ] = bit.bxor(hmac_key_mask_vals[ i + 2 ], iv_vals[ bit.band(i - 1, 0xF) + 1 ])
  hmac_vals[ i + 3 ] = bit.bxor(hmac_key_mask_vals[ i + 3 ], iv_vals[ bit.band(i, 0xF) + 1 ])
end

hmac_key = string.char(unpack(hmac_vals))

authinfo = '<X_PinCode>4410</X_PinCode>'
payload = '000000000000'
n = #authinfo

payload = payload .. string.char(bit.band(bit.rshift(n, 24), 0xFF))
payload = payload .. string.char(bit.band(bit.rshift(n, 16), 0xFF))
payload = payload .. string.char(bit.band(bit.rshift(n, 8), 0xFF))
payload = payload .. string.char(bit.band(n, 0xFF))

payload = payload .. authinfo

aes_cbc, err = aes:new(key, nil, aes.cipher(128, 'cbc'), { iv = iv }, nil, 1)
ciphertext = aes_cbc:encrypt(payload)

sig = encdec.hmacsha256(ciphertext, hmac_key, true)
encrypted_payload = encdec.base64enc(ciphertext .. sig)