Xbase++

Ed25519 Key Exchange (Shared Secret)

See more Ed25519 Examples

Demonstrates how to create an Ed25519 shared secret for use in key exchange.

Note: This example requires Chilkat v9.5.0.83 or greater.

Xbase++

LOCAL nSuccess
LOCAL cAlicePrivKey
LOCAL cBobPubKey
LOCAL oPrivKey
LOCAL oPubKey
LOCAL oEddsa
LOCAL cSharedSecret

nSuccess := 0

//  This example assumes the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  Alice's private key, a:
//      77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a
//  Alice's public key, X25519(a, 9):
//      8520f0098930a754748b7ddcb43ef75a0dbf3a0d26381af4eba4a98eaa9b4e6a
//  Bob's private key, b:
//      5dab087e624a8a4b79e17f8b83800ee66f3bb1292618b6fd1c2f8b27ff88e0eb
//  Bob's public key, X25519(b, 9):
//      de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f
//  Their shared secret, K:
//      4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742

cAlicePrivKey := "77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a"
cBobPubKey := "de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f"

oPrivKey := CreateObject("Chilkat.PrivateKey")
//  This example shows only one way of loading an Ed25519 private key.
//  Chilkat can load other formats (JWK, PEM, ASN.1 DER, etc.)  
//  You may do so by calling LoadAnyFormat or LoadAnyFormatFile.
nSuccess := oPrivKey:LoadEd25519(cAlicePrivKey, "")
IF (nSuccess == 0)
    ? oPrivKey:LastErrorText
    oPrivKey:destroy()
    RETURN
ENDIF

oPubKey := CreateObject("Chilkat.PublicKey")
nSuccess := oPubKey:LoadEd25519(cBobPubKey)
IF (nSuccess == 0)
    ? oPubKey:LastErrorText
    oPrivKey:destroy()
    oPubKey:destroy()
    RETURN
ENDIF

//  Create the shared secret:
oEddsa := CreateObject("Chilkat.EdDSA")
cSharedSecret := oEddsa:SharedSecretENC(oPrivKey, oPubKey, "hexlower")
IF (oEddsa:LastMethodSuccess == 0)
    ? oEddsa:LastErrorText
    oPrivKey:destroy()
    oPubKey:destroy()
    oEddsa:destroy()
    RETURN
ENDIF

? "Computed: " + cSharedSecret
? "Expected: 4a5d9d5ba4ce2de1728e3bf480350f25e07e21c947d19e3376f09b3c1e161742"

oPrivKey:destroy()
oPubKey:destroy()
oEddsa:destroy()