Function mp_int_to_binary

pub unsafe extern "C" fn mp_int_to_binary(
    z: mp_int,
    buf: *mut c_uchar,
    limit: c_int,
) -> mp_result

Converts z to 2’s complement binary, writing at most limit bytes into the given buf. Returns MP_TRUNC if the buffer limit was too small to contain the whole value. If this occurs, the contents of buf will be effectively garbage, as the function uses the buffer as scratch space.

The binary representation of z is in base-256 with digits ordered from most significant to least significant (network byte ordering). The high-order bit of the first byte is set for negative values, clear for non-negative values.

As a result, non-negative values will be padded with a leading zero byte if the high-order byte of the base-256 magnitude is set. This extra byte is accounted for by the mp_int_binary_len() function.