问从BCRYPT_SECRET_HANDLE中将共享密钥导出为字节数组

EN

DWORD bCryptStatus;
BCRYPT_SECRET_HANDLE secretHandle = NULL;
BCRYPT_KEY_HANDLE privateKeyHandle= NULL;
BCRYPT_KEY_HANDLE importedPublicKey = NULL;
BYTE *agreedSecret = NULL;
DWORD agreedSecretLength = 0;

//Import your keys here

//Generate the secret from the imported keys
bCryptStatus= BCryptSecretAgreement(privateKeyHandle, importedPublicKey, &secretHandle, 0);

//Now get the raw value of the secret agreement and copy it into an array
bCryptStatus= BCryptDeriveKey(
    secretHandle,          // Secret agreement handle
    BCRYPT_KDF_RAW_SECRET, // Key derivation function (null terminated unicode string)
    NULL,                  // KDF parameters
    NULL,                  // Buffer that recieves the derived key 
    0,                     // Length of the buffer
    &agreedSecretLength,   // Number of bytes copied to the buffer
    0);                    // Flags

    agreedSecret = (PBYTE)MALLOC(agreedSecretLength);

if (NULL != agreedSecret)
{
    _nCryptError = BCryptDeriveKey(
    secretHandle,          // Secret agreement handle
    BCRYPT_KDF_RAW_SECRET, // Key derivation function (null terminated unicode string)
    NULL,                  // KDF parameters
    agreedSecret,          // Buffer that recieves the derived key 
    agreedSecretLength,    // Length of the buffer
    &agreedSecretLength,   // Number of bytes copied to the buffer
    0);                    // Flags
}

//Free all the objects and the array when you are done, otherwise you will get memory leaks
if (NULL != importedPublicKey)
{
    BCryptDestroyKey(importedPublicKey);
}

if (NULL != privateKeyHandle)
{
    BCryptDestroyKey(privateKeyHandle);
}

if (NULL != secretHandle)
{
    BCryptDestroySecret(secretHandle);
}

if (NULL != agreedSecret)
{
    FREE(agreedSecret);
}