Python에서 해시 함수와 바이너리 데이터의 체크섬 계산 이해하기

import hashlib

# 해시 대상 문자열
data = "Hello, World!"

# MD5 해시 계산
md5_hash = hashlib.md5(data.encode()).hexdigest()

print(f"MD5: {md5_hash}")

# SHA-256 해시 계산
sha256_hash = hashlib.sha256(data.encode()).hexdigest()

print(f"SHA-256: {sha256_hash}")

def calculate_hash(data, algorithm='sha256'):
    hash_func = getattr(hashlib, algorithm)
    return hash_func(data.encode()).hexdigest()

# 사용 예
print(calculate_hash("Hello, World!", "md5"))
print(calculate_hash("Hello, World!", "sha256"))

import hashlib

data = "example"
md5_hash = hashlib.md5(data.encode()).hexdigest()
print(f"MD5: {md5_hash}")

sha1_hash = hashlib.sha1(data.encode()).hexdigest()
print(f"SHA-1: {sha1_hash}")

sha256_hash = hashlib.sha256(data.encode()).hexdigest()
print(f"SHA-256: {sha256_hash}")

sha3_256_hash = hashlib.sha3_256(data.encode()).hexdigest()
print(f"SHA-3-256: {sha3_256_hash}")

import zlib

data = b"example data"
crc32_checksum = zlib.crc32(data)
print(f"CRC32: {crc32_checksum}")

import zlib

# 데이터 준비
data = b"example data"

# CRC32 체크섬 계산
crc32_checksum = zlib.crc32(data)

# 체크섬 출력
print(f"CRC32: {crc32_checksum}")

# 파일 경로
file_path = 'example_file.txt'

# 파일을 바이너리 모드로 읽고 체크섬 계산
with open(file_path, 'rb') as file:
    data = file.read()
    crc32_checksum = zlib.crc32(data)

print(f"CRC32 of file: {crc32_checksum}")

# Adler-32 체크섬 계산
adler32_checksum = zlib.adler32(data)
print(f"Adler-32: {adler32_checksum}")

import zlib

def calculate_crc32(file_path):
    with open(file_path, 'rb') as file:
        data = file.read()
        return zlib.crc32(data)

# 체크섬을 계산할 파일 경로
file_path = 'example_file.txt'
checksum = calculate_crc32(file_path)

# 체크섬을 파일에 저장
with open(file_path + '.crc32', 'w') as checksum_file:
    checksum_file.write(f"{checksum}\n")

print(f"CRC32 checksum for {file_path}: {checksum}")

def verify_crc32(file_path):
    # 원본 파일의 체크섬을 계산
    original_checksum = calculate_crc32(file_path)

    # 저장된 체크섬을 읽음
    with open(file_path + '.crc32', 'r') as checksum_file:
        saved_checksum = int(checksum_file.read().strip())

    # 체크섬 비교
    if original_checksum == saved_checksum:
        print("File integrity verified: Checksums match.")
    else:
        print("File integrity check failed: Checksums do not match.")

# 무결성을 확인할 파일 경로
file_path = 'example_file.txt'
verify_crc32(file_path)

import hashlib

def calculate_sha256(file_path):
    sha256 = hashlib.sha256()
    with open(file_path, 'rb') as file:
        for block in iter(lambda: file.read(4096), b""):
            sha256.update(block)
    return sha256.hexdigest()

# SHA-256 체크섬을 계산할 파일 경로
file_path = 'example_file.txt'
sha256_checksum = calculate_sha256(file_path)

# 체크섬을 파일에 저장
with open(file_path + '.sha256', 'w') as checksum_file:
    checksum_file.write(f"{sha256_checksum}\n")

print(f"SHA-256 checksum for {file_path}: {sha256_checksum}")

def verify_sha256(file_path):
    # 원본 파일의 체크섬을 계산
    original_checksum = calculate_sha256(file_path)

    # 저장된 체크섬을 읽음
    with open(file_path + '.sha256', 'r') as checksum_file:
        saved_checksum = checksum_file.read().strip()

    # 체크섬 비교
    if original_checksum == saved_checksum:
        print("File integrity verified: Checksums match.")
    else:
        print("File integrity check failed: Checksums do not match.")

# 무결성을 확인할 파일 경로
file_path = 'example_file.txt'
verify_sha256(file_path)

try:
    # 오류가 발생할 가능성이 있는 코드
    result = 1 / 0
except ZeroDivisionError:
    # ZeroDivisionError가 발생했을 때 처리
    print("Error: Division by zero is not allowed.")

file_path = 'non_existent_file.txt'

try:
    with open(file_path, 'rb') as file:
        data = file.read()
        checksum = zlib.crc32(data)
        print(f"CRC32: {checksum}")
except FileNotFoundError:
    print(f"Error: The file {file_path} was not found.")
except PermissionError:
    print(f"Error: Permission denied for file {file_path}.")

def calculate_crc32(file_path):
    try:
        with open(file_path, 'rb') as file:
            data = file.read()
            return zlib.crc32(data)
    except FileNotFoundError:
        print(f"Error: The file {file_path} was not found.")
        return None
    except PermissionError:
        print(f"Error: Permission denied for file {file_path}.")
        return None
    except Exception as e:
        print(f"An unexpected error occurred: {e}")
        return None

file_path = 'example_file.txt'
checksum = calculate_crc32(file_path)
if checksum is not None:
    print(f"CRC32 checksum: {checksum}")

def get_file_path():
    return input("Enter the file path: ")

file_path = get_file_path()
while True:
    try:
        with open(file_path, 'rb') as file:
            data = file.read()
            checksum = zlib.crc32(data)
            print(f"CRC32: {checksum}")
        break
    except FileNotFoundError:
        print(f"Error: The file {file_path} was not found. Please try again.")
        file_path = get_file_path()
    except PermissionError:
        print(f"Error: Permission denied for file {file_path}. Please try again.")
        file_path = get_file_path()
    except Exception as e:
        print(f"An unexpected error occurred: {e}")
        break

import hashlib

def calculate_md5(file_path):
    try:
        with open(file_path, 'rb') as file:
            data = file.read()
            return hashlib.md5(data).hexdigest()
    except FileNotFoundError:
        print(f"Error: The file {file_path} was not found.")
    except PermissionError:
        print(f"Error: Permission denied for file {file_path}.")
    except Exception as e:
        print(f"An unexpected error occurred: {e}")

file_path = input("Enter the path to the text file: ")
md5_hash = calculate_md5(file_path)
if md5_hash:
    print(f"MD5 hash: {md5_hash}")

import hashlib

def calculate_sha256(file_path):
    try:
        sha256 = hashlib.sha256()
        with open(file_path, 'rb') as file:
            for block in iter(lambda: file.read(4096), b""):
                sha256.update(block)
        return sha256.hexdigest()
    except FileNotFoundError:
        print(f"Error: The file {file_path} was not found.")
    except PermissionError:
        print(f"Error: Permission denied for file {file_path}.")
    except Exception as e:
        print(f"An unexpected error occurred: {e}")

def verify_sha256(file_path):
    original_checksum = calculate_sha256(file_path)
    if not original_checksum:
        return

    checksum_file_path = file_path + '.sha256'
    try:
        with open(checksum_file_path, 'r') as checksum_file:
            saved_checksum = checksum_file.read().strip()
        if original_checksum == saved_checksum:
            print("File integrity verified: Checksums match.")
        else:
            print("File integrity check failed: Checksums do not match.")
    except FileNotFoundError:
        print(f"Error: The checksum file {checksum_file_path} was not found.")
    except PermissionError:
        print(f"Error: Permission denied for file {checksum_file_path}.")
    except Exception as e:
        print(f"An unexpected error occurred: {e}")

file_path = input("Enter the path to the file: ")
verify_sha256(file_path)