How to decode rsa with public and private key

Question

I have this public and private key, how to i decode this ?

thank you, very much.

and this is my flag: jmZpMnZtx0KZNkyYYo9poADkkETb7CkEgBsxoEyOrjwPW97OYpJnncZYNtIEhp0f+Blqf9dmc2EcDokA6k0haDmm1XsIiUVbfrx31C/1n5I3ZxzdclT0ZXIO441WGzIRlzoupnXPHiE9ZIOaUm06VTLzcBshFTl0rZhY4hjggik= — Đỗ Văn Hòa, Apr 26 '19 at 03:39
Cross site duplicate: https://security.stackexchange.com/questions/209047/how-to-decode-rsa-with-public-and-private-key — 1615903, Apr 26 '19 at 07:12
Seriously, don't spend more time on your profile than on your questions. — Maarten Bodewes, Apr 28 '19 at 13:14

score 0 · Answer 1 · answered Apr 26 '19 at 09:27

0

basically any ASN.1 decoder that recognizes DER structures will do...

for a free javascript version see https://lapo.it/asn1js/

answered Apr 26 '19 at 09:27

DarkSquirrel42

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score 0 · Answer 2 · answered Apr 27 '19 at 12:02

(This uses Python 3)

Open your CMD (windows) from start menu or TERMINAL (mac) from the utilities page in the launchpad. Type:

pip install pycrypto

if that gives you an error, try:

pip3 install pycrypto

(You might not have to do this) Select "Open Module" in the IDLE window, then type crypto. If it gives you an error, then you are good. Then, rename crypto to Crypto with a capital.

Go back to python and type this (in edit window):

from Crypto.PublicKey import RSA
key = RSA.importKey('file.pem') # where file.pem is where your keys are stored, in the format you had in your question
public = key.publickey()

output = public.encrypt('data'.encode('utf-8'),32) # 'data' is a placeholder
output = key.decrypt('data'.encode('utf-8'))

The output will be bytes, to convert to hexadecimal:

print(output.hex())

How to decode rsa with public and private key

2 Answers2