(Lianja) Ed25519 Key Exchange (Shared Secret)

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

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

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// 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

lcAlicePrivKey = "77076d0a7318a57d3c16c17251b26645df4c2f87ebc0992ab177fba51db92c2a"
lcBobPubKey = "de9edb7d7b7dc1b4d35b61c2ece435373f8343c85b78674dadfc7e146f882b4f"

loPrivKey = createobject("CkPrivateKey")
// 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.
llSuccess = loPrivKey.LoadEd25519(lcAlicePrivKey,"")
if (llSuccess = .F.) then
    ? loPrivKey.LastErrorText
    release loPrivKey
    return
endif

loPubKey = createobject("CkPublicKey")
llSuccess = loPubKey.LoadEd25519(lcBobPubKey)
if (llSuccess = .F.) then
    ? loPubKey.LastErrorText
    release loPrivKey
    release loPubKey
    return
endif

// Create the shared secret:
loEddsa = createobject("CkEdDSA")
lcSharedSecret = loEddsa.SharedSecretENC(loPrivKey,loPubKey,"hexlower")
if (loEddsa.LastMethodSuccess = .F.) then
    ? loEddsa.LastErrorText
    release loPrivKey
    release loPubKey
    release loEddsa
    return
endif

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


release loPrivKey
release loPubKey
release loEddsa