dreaife的休憩小栈

3.1 Symmetric Encryption#

Install Openssl, and prepare a plaintext document lx.txt with arbitrary content. Use a symmetric encryption algorithm to encrypt and decrypt lx.txt.

Requirements: There should be descriptive process text, explanations of the current operation and parameter meanings, and provide corresponding operation screenshots

3.2 Hash Functions#

Compute the MD5 and SHA-256 hash values of lx.txt

3.3 Asymmetric Encryption#

Create a 2048-bit RSA key pair (public-key cryptosystem). Use the created public key to encrypt lx.txt, and decrypt with the private key

1
OpenSSL> genrsa -out RsaPrivateKey.pem 2048
2
OpenSSL> rsa -in RsaPrivateKey.pem -pubout -out RsaPublicKey.pem
3
OpenSSL> rsautl -in plain.txt -out enc.txt -inkey RSAPublicKey.pem -pubin -encrypt
4
OpenSSL> rsautl -in enc.txt -out replain.txt -inkey RSAPrivateKey.pem -decrypt

Key pair generated

Public key generated

Files before and after encryption/decryption

4.4 Digital Signature#

Digitally sign lx.txt and verify

1
sha1 -out digest.txt lx.txt
2
rsautl -sign -inkey RsaPrivateKey.pem -in digest.txt -out signT.bin
3
rsautl -verify -inkey RsaPublicKey.pem -pubin -keyform PEM -in signT.bin

4.5 Certificate#

Create a self-signed certificate using openssl

1
genrsa -des3 -out ca.key 1024
2
rsa -in ca.key -out ca.key
3
req -new -x509 -key ca.key -out ca.crt -days 365
4
genrsa -des3 -out server.key 2048
5
req -new -key server.key -out server.csr
6
x509 -req -in server.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt -days 365

5.1 Issues and Solutions#

During the digital signature step, the command sha1 -out digest.txt lx.txt produced an error. The fix was that sha1 had been mistyped as shal; after entering sha1 -out digest.txt lx.txt, it worked.

5.2 Reflections#

• This experiment familiarized me with applying OpenSSL to encrypt files and create self-signed certificates, reinforcing the knowledge presented in class. Through this experiment, I have mastered the concrete workflow of using OpenSSL, learned the basic usage of common Linux configuration software, and improved my programming ability.
• Through these common Linux command operations and OpenSSL configuration and usage, I validated the knowledge learned in class.