Unicode C

Ed25519ph Sign and Verify

See more Ed25519 Examples

Demonstrates how to create an Ed25519ph signature, and then to verify it.

Note: This example requires Chilkat v9.5.0.91 or greater.

Unicode C

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

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

    success = FALSE;

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

    // Use the following test vector from https://www.rfc-editor.org/rfc/rfc8032#page-30

    //    -----TEST abc
    // 
    //    ALGORITHM:
    //    Ed25519ph
    // 
    //    SECRET KEY:
    //    833fe62409237b9d62ec77587520911e
    //    9a759cec1d19755b7da901b96dca3d42
    // 
    //    PUBLIC KEY:
    //    ec172b93ad5e563bf4932c70e1245034
    //    c35467ef2efd4d64ebf819683467e2bf
    // 
    //    MESSAGE (length 3 bytes):
    //    616263
    // 
    //    SIGNATURE:
    //    98a70222f0b8121aa9d30f813d683f80
    //    9e462b469c7ff87639499bb94e6dae41
    //    31f85042463c2a355a2003d062adf5aa
    //    a10b8c61e636062aaad11c2a26083406

    privKeyHex = L"833fe62409237b9d62ec77587520911e9a759cec1d19755b7da901b96dca3d42";
    pubKeyHex = L"ec172b93ad5e563bf4932c70e1245034c35467ef2efd4d64ebf819683467e2bf";

    privKey = CkPrivateKeyW_Create();
    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_AppendEncoded(bd,L"616263",L"hex");

    eddsa = CkEdDSAW_Create();
    // Indicate we want the Ed25519ph instance.
    CkEdDSAW_putAlgorithm(eddsa,L"Ed25519ph");

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

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

    // The expected output is: 98a70222f0b8121aa9d30f813d683f80....

    // 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 Ed25519ph signature is verified!\n");


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

    }