Where is the salt on the OpenSSL RSA algorithm? -

i find salting technique symmetric routines in openssl option -salt. can't find salt option asymmetric rsa algorithm.

a salt parameter makes sense password-based encryption. password used derive key used encryption. when ever pass password openssl encrypt something, might specify salt increase input entropy of whole process.

rsa not password-based. keys generated in advance , used directly. so, there no place use salt rsa.

there difference in structure of symmetric keys , rsa keys. keys symmetric block ciphers binary strings/arrays. can generated randomly or salted password. rsa keys on other hand have specific mathematical structure , cannot purely random.

this because 1 rsa key pair used encrypt communication between 2 parties in 1 direction. 1 cannot generate public key without private key rsa. have generated @ same time. wouldn't make sense let 1 party generate public key , other private key salt, because either

1. the keys not interoperable or
2. far worse, public key holder able generate private key along way.