I am learning cryptography and here is what I understood so far:
Story. I decide to talk with my friend over unencrypted channel. We exchange public keys with each other so that we can encrypt text files (messages). Once other party encrypts the message with my public key (the public key I given to my friend) and sends that encrypted file to me, I can decrypt message with my private key.
Here is how I create my key pair.
openssl genpkey -out privkey.pem -algorithm rsa -pkeyopt rsa_keygen_bits:4096 openssl pkey -pubout -in privkey.pem -out pubkey.pub
Then I can give this pubkey.pub to my friend who can encrypt message for me and send ecrypted file to me. I try this myself:
openssl enc -e -aes-256-cbc -in text.txt -out message.xxx -pass file:./pubkey.pub
This worked OK, I created encrypred file. But I cannot decrypt it:
openssl enc -d -aes-256-cbc -in message.xxx -out decrypted.txt -pass file:./privkey.pem bad decrypt 139927387231896:error:06065064:digital envelope routines:EVP_DecryptFinal_ex:bad decrypt:evp_enc.c:529:
I could decrypt with pub key but that is not what I was trying to achieve. What I would like to is implement simple practical example of Alice and Bob https://en.wikipedia.org/wiki/Public-key_cryptography It is all clear and easy in theory, but I could not find any easy and clear practical example like mine.
Added, list of files:
ls -alh total 28K drwxrwxr-x 2 user user 4.0K Sep 21 17:59 . drwxrwxr-x 11 user user 4.0K Sep 21 16:08 .. -rw-rw-r-- 1 user user 64 Sep 21 17:59 decrypted.txt -rw-rw-r-- 1 user user 96 Sep 21 17:58 message.xxx -rw-rw-r-- 1 user user 3.2K Sep 21 17:08 privkey.pem -rw-rw-r-- 1 user user 800 Sep 21 17:08 pubkey.pub -rw-rw-r-- 1 user user 74 Sep 21 17:58 text.txt