Usually the length of an array is sent in a parameter.
Most of the times the developer simply uses U2BE/U4BE to get this length. It
is possible to forge a tx with a `length > sizeof(uint16_t/uint32_t)` and trick the
user into signing something different from what is shown.
For instance consider the following parameter:
00 ... 01 00 00 00 01
if the developer uses U2BE/U4BE, it is possible that this length is shown to the user
and if it is, the user will see the length as 1.
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