[SWPU 2019]伟大的侦探

下载附件得到--MISC-伟大的侦探-misc.zip

但是需要密码

解压后能得到未经加密的密码.txt：

然后进行EBCDIC解密：

EBCDIC_TO_ASCII = [
    0x00, 0x01, 0x02, 0x03, 0x9C, 0x09, 0x86, 0x7F, 0x97, 0x8D, 0x8E, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
    0x10, 0x11, 0x12, 0x13, 0x9D, 0x0A, 0x08, 0x87, 0x18, 0x19, 0x92, 0x8F, 0x1C, 0x1D, 0x1E, 0x1F,
    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x17, 0x1B, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x05, 0x06, 0x07,
    0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04, 0x98, 0x99, 0x9A, 0x9B, 0x14, 0x15, 0x9E, 0x1A,
    0x20, 0xA0, 0xE2, 0xE4, 0xE0, 0xE1, 0xE3, 0xE5, 0xE7, 0xF1, 0xA2, 0x2E, 0x3C, 0x28, 0x2B, 0x7C,
    0x26, 0xE9, 0xEA, 0xEB, 0xE8, 0xED, 0xEE, 0xEF, 0xEC, 0xDF, 0x21, 0x24, 0x2A, 0x29, 0x3B, 0xAC,
    0x2D, 0x2F, 0xC2, 0xC4, 0xC0, 0xC1, 0xC3, 0xC5, 0xC7, 0xD1, 0xA6, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
    0xF8, 0xC9, 0xCA, 0xCB, 0xC8, 0xCD, 0xCE, 0xCF, 0xCC, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
    0xD8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0xAB, 0xBB, 0xF0, 0xFD, 0xFE, 0xB1,
    0xB0, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70, 0x71, 0x72, 0xAA, 0xBA, 0xE6, 0xB8, 0xC6, 0xA4,
    0xB5, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0xA1, 0xBF, 0xD0, 0x5B, 0xDE, 0xAE,
    0xAC, 0xA3, 0xA5, 0xB7, 0xA9, 0xA7, 0xB6, 0xBC, 0xBD, 0xBE, 0xDD, 0xA8, 0xAF, 0x5D, 0xB4, 0xD7,
    0x7B, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0xAD, 0xF4, 0xF6, 0xF2, 0xF3, 0xF5,
    0x7D, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0xB9, 0xFB, 0xFC, 0xFA, 0xFF, 0xB2,
    0x5C, 0xF7, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0xB3, 0xD9, 0xDA, 0xDB, 0xDC, 0x30,
    0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0xB3, 0xE3, 0xE2, 0x5E, 0x3C, 0x3E, 0xFF
]

ASCII_TO_EBCDIC = [0] * 256
for i in range(256):
    ASCII_TO_EBCDIC[EBCDIC_TO_ASCII[i]] = i

def ebcdic_to_ascii(ebcdic_bytes):
    return bytes(EBCDIC_TO_ASCII[b] for b in ebcdic_bytes)

def ascii_to_ebcdic(ascii_bytes):
    return bytes(ASCII_TO_EBCDIC[b] for b in ascii_bytes)

def read_file(file_path):
    with open(file_path, 'rb') as file:
        return file.read()

def write_file(file_path, data):
    with open(file_path, 'wb') as file:
        file.write(data)

def main(input_file, output_file, conversion):
    data = read_file(input_file)
    if conversion == 'ebcdic_to_ascii':
        converted_data = ebcdic_to_ascii(data)
    elif conversion == 'ascii_to_ebcdic':
        converted_data = ascii_to_ebcdic(data)
    else:
        raise ValueError("Invalid conversion type. Use 'ebcdic_to_ascii' or 'ascii_to_ebcdic'.")
    write_file(output_file, converted_data)
    print(f"Conversion {conversion} completed. Output written to {output_file}")

if __name__ == "__main__":
    import argparse

    parser = argparse.ArgumentParser(description="Convert between EBCDIC and ASCII.")
    parser.add_argument("input_file", help="Path to the input file")
    parser.add_argument("output_file", help="Path to the output file")
    parser.add_argument("conversion", choices=["ebcdic_to_ascii", "ascii_to_ebcdic"], help="Conversion type")

    args = parser.parse_args()
    main(args.input_file, args.output_file, args.conversion)

保存为ebcdic_ascii_converter.py运行：

python ebcdic_ascii_converter.py EBCDIC.txt output_ascii.txt ebcdic_to_ascii

EBCDIC.txt即为密码.txt

压缩包密码为"wllm_is_the_best_team!"

在misc目录下得到：

对照表：

https://blog.csdn.net/mochu7777777/article/details/109387134

对照得：NSSCTF{iloveholmesandwllm}

[BJDCTF 2020]认真你就输了

下载得到10.xlsx

使用file-format:

binwalk:

binwalk分离：

根据提示得到flag:

[BJDCTF 2020]纳尼

下载附件得到：

但是用6.gif打不开

需要手动添加文件头

添加后能正常打开

Q1RGe3dhbmdfYmFvX3FpYW5nX2lzX3NhZH0=

[UTCTF 2020]Zero

下载后得到zero.txt

发现这儿有点重叠，显示不全

根据题目名称，猜测这里是零宽隐写

零宽解密：https://330k.github.io/misc_tools/unicode_steganography.html

NSSCTF{whyNOT@sc11_4927aajbqk14}