Enclave

How buffer overflow happens in C SGX enclave memcpy and how to fix it

A critical buffer overflow vulnerability was discovered in `backend/sgx/enclave/enclave.c` where the `ecall_store_data` function performed `memcpy` operations without proper bounds checking against the actual destination buffer size. An attacker could supply a malicious `data_len` parameter to overflow the enclave's secure storage buffer, potentially corrupting trusted execution environment memory. The fix replaces a hardcoded magic number check with a precise size comparison against the actual