eft_validate_cvv.c

Example of EFT to generate and verify CVV.

See Note on examples.

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
 
#include <dinamo.h> /* header do Dinamo */
 
#define HOST_ADDR "127.0.0.1"
#define USER_ID "master"
#define USER_PWD "12345678"
 
#define PAN "4123456789012345"
#define EXPIRATION_DATE "8701"
#define SERVICE_CODE "101"
 
#define CVV_RESULT "561"
 
#define KEY_ID "KEY_CVV"
#define KEY_VALUE { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0xFE, 0xDC, 0xBA, 0x98, 0x76, 0x54, 0x32, 0x10 }
#define KEY_TYPE ALG_3DES_112
 
int main()
{
    int nRet = 0;
    char szCVV[MIN_CVV_LEN];
    struct AUTH_PWD authPwd;
    HSESSIONCTX hSession = NULL;
    HKEYCTX hKey = NULL;
    BYTE pbKeyData[] = KEY_VALUE;
 
    //Inicializa as bibliotecas do Dinamo
    nRet =  DInitialize(0);
 
    if (nRet){
        printf("Function failure: DInitialize \nError code: %d\n", nRet);
        goto clean;
    }
 
    printf("Libraries initialized.\n");
 
    //Inicializa a estrutura para conexao com o HSM
    strncpy(authPwd. szAddr, HOST_ADDR, sizeof(authPwd.szAddr));
    authPwd. nPort = DEFAULT_PORT;
    strncpy(authPwd. szUserId, USER_ID, sizeof(authPwd.szUserId));
    strncpy(authPwd. szPassword, USER_PWD, sizeof(authPwd.szPassword));
 
    nRet = DOpenSession(&hSession, SS_USER_PWD,(BYTE *)&authPwd, sizeof(authPwd), ENCRYPTED_CONN);
 
    if (nRet){
        printf("Function failure: DOpenSession \nError code: %d\n", nRet);
        goto clean;
    }
    printf("Session with Dinamo established.\n");
 
    // Importa chave temporaria
    nRet = DImportKey( hSession, KEY_ID, NULL, PLAINTEXTKEY_BLOB, KEY_TYPE, TEMPORARY_KEY, pbKeyData, sizeof(pbKeyData), &hKey );
 
    if(nRet){
        printf("Function failure: DImportKey\nError code: %d\n", nRet);
        goto clean;
    }
 
    // Gera CVV baseado na chave temporaria e demais parametrizacoes
    nRet = DGenerateCVV( hSession, KEY_ID, PAN, EXPIRATION_DATE, SERVICE_CODE, szCVV, 0);
 
    if(nRet){
        printf("Function failure: DGenerateCVV\nError code: %d\n", nRet);
        goto clean;
    }
 
    // Validacao do algoritmo - compara CVV resultante com o CVV esperado
    // (com chave e demais parametrizacoes iguais o resultado e sempre o mesmo)
    if( strcmp( szCVV, CVV_RESULT ) ) {
        printf("Failed to compare generated CVV (%s) and expected CVV (%s).", szCVV, CVV_RESULT);
    }
 
    // Verifica se o CVV gerado d realmente valido no HSM (usando mesma chave e parametrizacoes)
    nRet = DVerifyCVV( hSession, KEY_ID, PAN, EXPIRATION_DATE, SERVICE_CODE, szCVV, 0);
 
    if(nRet){
        printf("Function failure: DVerifyCVV\nError code: %d\n", nRet);
        goto clean;
    }
 
    printf("CVV successfully verified!");
 
    clean:
 
    if (hKey) {
        DDestroyKey(&hKey, 0);
        printf("Key context released.\n");
    }
 
    if (hSession) {
        DCloseSession(&hSession, 0);
        printf("Session closed.\n");
    }
 
    DFinalize();
    printf("Libraries finished.\n");
 
    return nRet;
}