Here are some quick one liners to do a laundry list of things with openssl.
openssl s_client -connect domain.com:443
or for more info
openssl s_client -state -verify -showcerts -connect domain.com:443
Check speed for SSL methods
openssl speed
openssl speed rsa
for SMPopenssl speed rsa -multi 2
Check connection time
openssl s_time -connect remote.host:443
Check SMTP/TLS
openssl s_client -connect remote.host:25 -starttls smtp
Base 64 encoding
send encoded contents of file.txt to stdout
openssl enc -base64 -in file.txt
same, but write contents to file.txt.enc
openssl enc -base64 -in file.txt -out file.txt.enc
Diagnose SSL error codes
sshd[31784]: error: RSA_public_decrypt failed: error:0407006A:lib(4):func(112):reason(106)
openssl errstr 0407006A
Generate crypt style hash
openssl passwd MySecret
Generate shadow style hash
openssl passwd -1 MySecret
with salt
openssl passwd -1 -salt sXiKzkus MySecret
Test for prime numbers
openssl prime 119054759245460753
