Day 29 of #100DaysOfCode
Built a Bash script to monitor disk usage and generate alerts when usage exceeds a defined threshold.
Parsed disk usage with df and awk
Logged warnings with timestamps
Implemented threshold-based monitoring
Day 28 of #100DaysOfCode
Built a Bash script to monitor active TCP connections.
* Listed ESTABLISHED connections
* Grouped connections by remote IP
* Counted connections per host
* Used ss, netstat, awk, and Bash scripting
Day 27 of #100DaysOfCode
Worked on IPTables firewall configuration.
Created custom chains
Configured FORWARD chain rules
Allowed selective website access per client
Configured DNS traffic rules
Applied default deny policy using REJECT
Day 26 of #100DaysOfCode
Learned Nmap target specification and host discovery techniques.
Covered CIDR notation, IP range scanning, target files, host exclusion, interface selection, and basic Docker lab scanning.
#Nmap#CyberSecurity#Networking#Linux#100DaysOfCode
Day 25 of #100DaysOfCode
Built a simple Bash script to:
* List user cron jobs
* Search for a specific cron job
* Verify scheduled tasks
#Linux#Bash#Cron#Scripting#100DaysOfCode
GitHub: https://t.co/y0b5R4jT7J
LinkedIn: https://t.co/arxcqoZYFm
X: https://t.co/WfRUfmSAjj
Day 22 of #100DaysOfCode
Learned hashing and digital signatures using OpenSSL.
Generated MD5, SHA-256, and SHA-512 hashes
Created a self-signed certificate
Digitally signed a PDF document
Verified signature integrity and authenticity
Day 21 of #100DaysOfCode
Learned Public Key Infrastructure (PKI) and HTTPS deployment.
Created Root CA and Sub CA
Issued a website certificate from the Sub CA
Configured Subject Alternative Name (SAN)
Built the certificate chain
Configured Apache HTTPS for https://t.co/ghyMFCZsRz
Day 20 of #100DaysOfCode
Generated a self-signed RSA certificate
Examined X.509 certificate fields
Verified Issuer, Subject, Validity, and Public Key
Compared certificate data with the RSA private key
Learned why self-signed certificates have Issuer = Subject
Day 19 of #100DaysOfCode
Explored RSA and ECC cryptography using OpenSSL
• RSA key generation and analysis
• Self-signed X.509 certificate creation
• Public & Private key concepts
• Certificate inspection and verification
• ECC fundamentals and ECDLP
• RSA vs ECC security