curve25519 {openssl}

Curve25519

Description

Curve25519 is a recently added low-level algorithm that can be used both for diffie-hellman (called X25519) and for signatures (called ED25519). Note that these functions are only available when building against version 1.1.1 or newer of the openssl library. The same functions are also available in the sodium R package.

Usage

read_ed25519_key(x)

read_ed25519_pubkey(x)

read_x25519_key(x)

read_x25519_pubkey(x)

ed25519_sign(data, key)

ed25519_verify(data, sig, pubkey)

x25519_diffie_hellman(key, pubkey)

Arguments

x

a 32 byte raw vector with (pub)key data

data

raw vector with data to sign or verify

key

private key as returned by read_ed25519_key or ed25519_keygen

sig

raw vector of length 64 with signature as returned by ed25519_sign

pubkey

public key as returned by read_ed25519_pubkey or key$pubkey

Examples

# Generate a keypair
if(openssl_config()$x25519){
key <- ed25519_keygen()
pubkey <- as.list(key)$pubkey

# Sign message
msg <- serialize(iris, NULL)
sig <- ed25519_sign(msg, key)

# Verify the signature
ed25519_verify(msg, sig, pubkey)

# Diffie Hellman example:
key1 <- x25519_keygen()
key2 <- x25519_keygen()

# Both parties can derive the same secret
x25519_diffie_hellman(key1, key2$pubkey)
x25519_diffie_hellman(key2, key1$pubkey)

# Import/export sodium keys
rawkey <- sodium::sig_keygen()
rawpubkey <- sodium::sig_pubkey(rawkey)
key <- read_ed25519_key(rawkey)
pubkey <- read_ed25519_pubkey(rawpubkey)

# To get the raw key data back for use in sodium
as.list(key)$data
as.list(pubkey)$data
}