add cert to keystore

// convert to pem file
openssl x509 -in cert.der -inform der -outform pem -out cert.pem
openssl rsa -in cert.key -inform der -out certkey.pem -outform pem

//export to p12 format
openssl pkcs12 -export -in cert.pem -inkey certkey.pem -name alias -out cert.p12
openssl pkcs12 -export -out certificate.p12 -inkey privateKey.key -in certificate.crt -certfile CACert.crt

//delete old alias
keytool -delete -alias alias -keystore keystore 
keytool -delete -alias intermediate -keystore keystore

//import
keytool -v -importkeystore -srckeystore cert.p12 -srcstoretype PKCS12 -destkeystore keystore -deststoretype JKS
keytool -import -alias intermediate -file intermediate.cer -keystore keystore

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Convert x509 to PEM
openssl x509 -in certificatename.cer -outform PEM -out certificatename.pem


Convert PEM to DER

openssl x509 -outform der -in certificatename.pem -out certificatename.der


Convert DER to PEM

openssl x509 -inform der -in certificatename.der -out certificatename.pem


Note: The PKCS#7 or P7B format is stored in Base64 ASCII format and has a file extension of .p7b or .p7c.
A P7B file only contains certificates and chain certificates (Intermediate CAs), not the private key. The most common platforms that support P7B files are Microsoft Windows and Java Tomcat.

Convert PEM to P7B

openssl crl2pkcs7 -nocrl -certfile certificatename.pem -out certificatename.p7b -certfile CACert.cer


Convert PKCS7 to PEM

openssl pkcs7 -print_certs -in certificatename.p7b -out certificatename.pem



Note: The PKCS#12 or PFX format is a binary format for storing the server certificate, intermediate certificates, and the private key in one encryptable file. PFX files usually have extensions such as .pfx and .p12. PFX files are typically used on Windows machines to import and export certificates and private keys.

Convert pfx to PEM

openssl pkcs12 -in certificatename.pfx -out certificatename.pem


Convert PFX to PKCS#8
Note: This requires 2 commands

Step 1: Convert PFX to PEM

openssl pkcs12 -in certificatename.pfx -nocerts -nodes -out certificatename.pem


Step 2: Convert PEM to PKCS8

openSSL pkcs8 -in certificatename.pem -topk8 -nocrypt -out certificatename.pk8


Convert P7B to PFX
Note: This requires 2 commands

Step 1: Convert P7B to CER

openssl pkcs7 -print_certs -in certificatename.p7b -out certificatename.cer


Step 2: Convert CER and Private Key to PFX

openssl pkcs12 -export -in certificatename.cer -inkey privateKey.key -out certificatename.pfx -certfile  cacert.cer