CTF Crypto tools
OpenSSL
-
Open-source implementation of SSL and TLS
protocols - Useful toolkit of cryptographic
- Many bugs and vulnerabilities
OpenSSL : Digest
SHA
SHA-1
openssl dgst -sha1 plaintext
SHA-2
openssl dgst –sha256 plaintext
openssl dgst –sha512 plaintext
OpenSSL : AES
AES Encrypt
openssl enc –aes128 -e -in plaintext -out c.aes
AES Decrypt
openssl enc –aes128 -d -in c.aes -out c.aes.dec
OpenSSL : RSA
RSA Private Key
- Gen Private Key
openssl genrsa -out priv.pem
- View Private Key
openssl rsa –text –in priv.pem –out priv.pem.info
p , q , N , d , e
RSA Public Key
- Extract Public Key
openssl rsa –in priv.pem –pubout –out pub.pem
- View Public Key
openssl rsa –text –pubin –in pub.pem
–out public.pem.info
N , e
RSA Encrypt
openssl rsautl –encrypt –pubin –inkey pub.pem
–in plaintext –out ciphertext
RSA Decrypt
openssl rsautl -decrypt -inkey priv.pem
-in ciphertext -out cipheretext.decrypt
RSA : Factoring N
Tools
・factordb
http://factordb.com/
・yafu
http://sourceforge.net/projects/yafu/
・Cado-NFS
http://cado-nfs.gforge.inria.fr/
・Mesieve
https://github.com/Tojaj/rsaalgorithm/tree/master/msieve-1.51
Construct Private Key
Tools
-
rsatool
https://github.com/ius/rsatool
computing d with given N , e , p , q
construct .pem with given N , d
example

從 pub 拿 N,e

解 N 得 p,q


用 rsatool

CTF Crypto tools
By ZAL
CTF Crypto tools
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