(Unicode C) Ed25519 Sign and Verify

Demonstrates how to create an Ed25519 signature, and then to verify it.

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

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkPrivateKeyW.h>
#include <C_CkBinDataW.h>
#include <C_CkEdDSAW.h>
#include <C_CkPublicKeyW.h>

void ChilkatSample(void)
    {
    const wchar_t *privKeyHex;
    const wchar_t *pubKeyHex;
    HCkPrivateKeyW privKey;
    BOOL success;
    HCkBinDataW bd;
    HCkEdDSAW eddsa;
    const wchar_t *hexSig;
    HCkPublicKeyW pubKey;
    BOOL bVerified;

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

    privKeyHex = L"1498b5467a63dffa2dc9d9e069caf075d16fc33fdd4c3b01bfadae6433767d93";
    pubKeyHex = L"b7a3c12dc0c8c748ab07525b701122b88bd78f600c76342d27f25e5f92444cde";

    privKey = CkPrivateKeyW_Create();
    // 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.
    success = CkPrivateKeyW_LoadEd25519(privKey,privKeyHex,pubKeyHex);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privKey));
        CkPrivateKeyW_Dispose(privKey);
        return;
    }

    // The data to be signed...
    bd = CkBinDataW_Create();
    CkBinDataW_AppendString(bd,L"Message for Ed25519 signing",L"utf-8");

    eddsa = CkEdDSAW_Create();
    hexSig = CkEdDSAW_signBdENC(eddsa,bd,L"hexlower",privKey);

    wprintf(L"signature = %s\n",hexSig);

    // The expected output is: 6dd355667fae4eb43c6e0ab92e870edb2de0a88cae12dbd8591507f584fe4912babff497f1b8edf9567d2483d54ddc6459bea7855281b7a246a609e3001a4e08

    // Verify the signature..
    pubKey = CkPublicKeyW_Create();
    success = CkPublicKeyW_LoadEd25519(pubKey,pubKeyHex);
    if (success == FALSE) {
        wprintf(L"%s\n",CkPublicKeyW_lastErrorText(pubKey));
        CkPrivateKeyW_Dispose(privKey);
        CkBinDataW_Dispose(bd);
        CkEdDSAW_Dispose(eddsa);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    bVerified = CkEdDSAW_VerifyBdENC(eddsa,bd,hexSig,L"hexlower",pubKey);
    if (bVerified == FALSE) {
        wprintf(L"%s\n",CkEdDSAW_lastErrorText(eddsa));
        wprintf(L"Failed to verify the signature.\n");
        CkPrivateKeyW_Dispose(privKey);
        CkBinDataW_Dispose(bd);
        CkEdDSAW_Dispose(eddsa);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    wprintf(L"The Ed25519 signature is verified!\n");


    CkPrivateKeyW_Dispose(privKey);
    CkBinDataW_Dispose(bd);
    CkEdDSAW_Dispose(eddsa);
    CkPublicKeyW_Dispose(pubKey);

    }