1.安装环境依赖

注意：此工具环境基于Python3

  1. root@kali:~/桌面/RSA/env/RsaCtfTool# sudo apt-get install libgmp3-dev libmpc-dev

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2.安装python支持库，这里使用的是python3

root@kali:~/桌面/RSA/env/RsaCtfTool# pip3 install -r "requirements.txt"  -i https://pypi.tuna.tsinghua.edu.cn/simple

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3.验证一下，是否安装成功

root@kali:~/桌面/RSA/env/RsaCtfTool# python3 RsaCtfTool.py 
usage: RsaCtfTool.py [-h] [--publickey PUBLICKEY] [--output OUTPUT]
                     [--timeout TIMEOUT] [--createpub] [--dumpkey] [--ext]
                     [--uncipherfile UNCIPHERFILE] [--uncipher UNCIPHER]
                     [--verbosity {CRITICAL,ERROR,WARNING,DEBUG,INFO}]
                     [--private] [--ecmdigits ECMDIGITS] [-n N] [-p P] [-q Q]
                     [-e E] [--key KEY] [--password PASSWORD]
                     [--attack {boneh_durfee,roca,pollard_p_1,noveltyprimes,smallfraction,comfact_cn,pastctfprimes,siqs,smallq,ecm,primefac,mersenne_primes,partial_q,ecm2,factordb,londahl,fermat,wiener,qicheng,cube_root,hastads,same_n_huge_e,commonfactors,all}]

RSA CTF Tool

optional arguments:
  -h, --help            show this help message and exit
  --publickey PUBLICKEY
                        public key file. You can use wildcards for multiple
                        keys.
  --output OUTPUT       output file for results (privates keys, plaintext
                        data).
  --timeout TIMEOUT     Timeout for long attacks.
  --createpub           Take n and e from cli and just print a public key then
                        exit
  --dumpkey             Just dump the RSA variables from a key - n,e,d,p,q
  --ext                 Extended dump of RSA private variables in --dumpkey
                        mode - dp,dq,pinv,qinv).
  --uncipherfile UNCIPHERFILE
                        uncipher a file
  --uncipher UNCIPHER   uncipher a cipher
  --verbosity {CRITICAL,ERROR,WARNING,DEBUG,INFO}
                        verbose mode
  --private             Display private key if recovered
  --ecmdigits ECMDIGITS
                        Optionally an estimate as to how long one of the
                        primes is for ECM method
  -n N                  Specify the modulus. format : int or 0xhex
  -p P                  Specify the first prime number. format : int or 0xhex
  -q Q                  Specify the second prime number. format : int or 0xhex
  -e E                  Specify the public exponent. format : int or 0xhex
  --key KEY             Specify the private key file.
  --password PASSWORD   Private key password if needed.
  --attack {boneh_durfee,roca,pollard_p_1,noveltyprimes,smallfraction,comfact_cn,pastctfprimes,siqs,smallq,ecm,primefac,mersenne_primes,partial_q,ecm2,factordb,londahl,fermat,wiener,qicheng,cube_root,hastads,same_n_huge_e,commonfactors,all}
                        Specify the attack mode.

4.用法

1). 已知公钥(自动求私钥) –publickey，密文 — uncipherfile

此题以攻防世界中级区—wtc_rsa_bbq为例
将文件解压复制到RsaCtfTool里：(或者指定路径)

root@kali:~/桌面/RSA/env/RsaCtfTool# python3 RsaCtfTool.py --publickey /root/桌面/_cry200.extracted/key.pem  --uncipherfile /root/桌面/_cry200.extracted/cipher.bin

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解密的16进制信息如上图，往后翻一点可以看到flag，其实丢入Hxd也是一样的效果
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2）已知公钥求私钥(cr4-poor-rsa 攻防世界)

python3 RsaCtfTool.py --publickey 公钥文件 --private

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由此计算出私钥为：

-----BEGIN RSA PRIVATE KEY-----
MIH5AgEAAjJSqZ4knufPPAy/ljoAlmF3K8nN9uHj+/xuRKB6Xg+JRFep+Bw64TKs
VoPTWyi6XDJCQwIDAQABAjIzrQnKBvUPnpCxrK5x85DWuS8dbTtmFP+HEYHE3wja
TF9QEkV6ZDCUBers1jQeQwJ5MQIaAImWgwYMdrnA3lgaaeDqnZG+0Qcb6x2SSjcC
GgCZzedK7e6Hrf/daEy8R451mHC08gaS9lJVAhlmZEB1y+i/LC1L27xXycIhqKPe
aoR6qVfZAhlbPhKLmhFavne/AqQbQhwaWT/rqHUL9EMtAhk5pem+TgbW3zCYF8v7
j0mjJ31NC+0sLmx5
-----END RSA PRIVATE KEY-----

由于加密信息给的是一段base64（这里可以直接将base64转换为一个文件，再使用Openssl 解密rsa），为方便所以这里使用CaptfEncoder进行解密RSA:
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