openssl (version 2.3.0)

ec_dh: Diffie-Hellman Key Agreement

Description

Key agreement is one-step method of creating a shared secret between two peers. Both peers can independently derive the joined secret by combining his or her private key with the public key from the peer.

Usage

ec_dh(key = my_key(), peerkey, password = askpass)

Arguments

key

your own private key

peerkey

the public key from your peer

password

passed to read_key for reading protected private keys

Details

Currently only Elliptic Curve Diffie Hellman (ECDH) is implemented.

References

https://wiki.openssl.org/index.php/EVP_Key_Agreement, https://wiki.openssl.org/index.php/Elliptic_Curve_Diffie_Hellman

Examples

if (FALSE) {
# Need two EC keypairs from the same curve
alice_key <- ec_keygen("P-521")
bob_key <- ec_keygen("P-521")

# Derive public keys
alice_pub <- as.list(alice_key)$pubkey
bob_pub <- as.list(bob_key)$pubkey

# Both peers can derive the (same) shared secret via each other's pubkey
ec_dh(alice_key, bob_pub)
ec_dh(bob_key, alice_pub)
}