import hashlib

def audit_legacy_checksum(payload_hex):
    print(f"--- Legacy Checksum Audit (Double SHA256) ---")
    data = bytes.fromhex(payload_hex)

    # Double SHA256
    hash1 = hashlib.sha256(data).digest()
    hash2 = hashlib.sha256(hash1).digest()

    checksum = hash2[:4]
    print(f"[*] Input Data: {payload_hex}")
    print(f"[*] Full Hash:  {hash2.hex()}")
    print(f"[SUCCESS] 4-Byte Checksum: {checksum.hex()}")
    return checksum.hex()

def bech32_polymod(values):
    """Internal Bech32 polynomial generator."""
    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
    chk = 1
    for value in values:
        top = chk \u003e\u003e 25
        chk = (chk \u0026 0x1ffffff) \u003c\u003c 5 ^ value
        for i in range(5):
            chk ^= generator[i] if ((top \u003e\u003e i) \u0026 1) else 0
    return chk

def audit_bech32_checksum(hrp, data_values):
    print(f"\n--- Bech32 Checksum Audit (BCH Polynomial) ---")

    # HRP expansion (simplified for mainnet 'bc')
    hrp_expanded = [3, 3, 0, 2, 3] # 'bc' expansion
    values = hrp_expanded + data_values + [0]*6

    # Calculate remainder
    polymod = bech32_polymod(values) ^ 1

    print(f"[*] Input HRP:  {hrp}")
    print(f"[*] Data Points: {data_values}")
    print(f"[SUCCESS] Polynomial Remainder: {hex(polymod)}")

# --- Simulation ---

# Case 1: Legacy address payload (Version 00 + Hash)
legacy_payload = "0079be667ef9dcbbac55a06295ce870b07029bfc"
audit_legacy_checksum(legacy_payload)

# Case 2: Bech32 data points (simplified)
# Representing a witness version and hash data
bech32_data = [0, 14, 20, 15, 7, 22] 
audit_bech32_checksum("bc", bech32_data)