//------------------------------------------------------------------------ #include <vcl.h> #pragma hdrstop #include "uMain.h" //------------------------------------------------------------------------ #pragma package(smart_init) #pragma resource "*.dfm" TForm1 *Form1; //------------------------------------------------------------------------ #define ENCRYPT_ALGORITHM   CALG_RC4 #define KEYLENGTH           0x00800000 static void EncryptFunc(sqlite3_context *context,     int argc, sqlite3_value **argv) {  if      (argc == 0)   sqlite3_result_error(context, "Error: No Data)", -1);  else if (argc == 1)   sqlite3_result_error(context, "Error: No Password", -1);  else if (argc != 2)   sqlite3_result_error(context, "Error: Invalid param count", -1);  else  {   const unsigned char *pwd;   pwd = (const unsigned char *)sqlite3_value_text(argv[1]);   const unsigned char *src;   src = (const unsigned char *)sqlite3_value_blob(argv[0]);   if ( strlen( pwd ) > 0 )   {    HCRYPTPROV hCryptProv  = NULL;    HCRYPTKEY  hKey        = NULL;    HCRYPTHASH hHash       = NULL;    // Get the Handle to the default provider    if ( !CryptAcquireContext( &hCryptProv,     NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, 0 ) )    {     if ( GetLastError() == NTE_BAD_KEYSET )     {      if (!CryptAcquireContext(&hCryptProv,       NULL, MS_DEF_PROV,       PROV_RSA_FULL, CRYPT_NEWKEYSET))      {       // CryptAcquireContext() failed.       sqlite3_result_error(        context,        "Error: CryptAcquireContext()",        -1);       return;      }     }     else     {      // CryptAcquireContext() failed.      sqlite3_result_error(       context,       "Error: CryptAcquireContext()",       -1);      return;     }    }    // Create Hash object    if ( !CryptCreateHash( hCryptProv, CALG_MD5, 0, 0, &hHash ) )    {     // Error during CryptCreateHash()     sqlite3_result_error(      context,      "Error: CryptCreateHash()",      -1);     return;    }    // Hash the password    if ( !CryptHashData( hHash, pwd, strlen(pwd), 0 ) )    {     // Error during CryptHashData     sqlite3_result_error(      context,      "Error: CryptHashData()",      -1);     return;    }    // Derive a session key from the hash object    if ( !CryptDeriveKey( hCryptProv, ENCRYPT_ALGORITHM,     hHash, KEYLENGTH, &hKey ) )    {     // Error during CryptDeriveKey     sqlite3_result_error(      context,      "Error: CryptDeriveKey()",      -1);     return;    }    // Encrypt    unsigned long length = strlen(src);    unsigned char *dst = (unsigned char *)malloc(length + 1);    memcpy(dst, src, length + 1 );    if ( !CryptEncrypt( hKey, NULL, TRUE, 0, dst, &length, length ) )    {     // Error during CryptEncrypt     sqlite3_result_error(      context,      "Error: CryptEncrypt()",      -1);     free( dst );     return;    }    sqlite3_result_blob(     context,     dst,     strlen( dst ),     SQLITE_TRANSIENT );    free( dst );   }  } } //------------------------------------------------------------------------ static void DecryptFunc(sqlite3_context *context,     int argc, sqlite3_value **argv) {  if      (argc == 0)   sqlite3_result_error(context, "Error: No Data)", -1);  else if (argc == 1)   sqlite3_result_error(context, "Error: No Password", -1);  else if (argc != 2)   sqlite3_result_error(context, "Error: Invalid param count", -1);  else  {   const unsigned char *src;   src = (const unsigned char *)sqlite3_value_blob(argv[0]);   const unsigned char *pwd;   pwd = (const unsigned char *)sqlite3_value_text(argv[1]);   if ( strlen( pwd ) > 0 )   {    HCRYPTPROV hCryptProv  = NULL;    HCRYPTKEY  hKey        = NULL;    HCRYPTHASH hHash       = NULL;    // Get the Handle to the default provider    if ( !CryptAcquireContext( &hCryptProv, NULL,     MS_ENHANCED_PROV, PROV_RSA_FULL, 0 ) )    {     if ( GetLastError() == NTE_BAD_KEYSET )     {      if (!CryptAcquireContext(&hCryptProv, NULL,       MS_DEF_PROV, PROV_RSA_FULL,       CRYPT_NEWKEYSET))      {       // CryptAcquireContext() failed.       sqlite3_result_error(        context,        "Error: CryptAcquireContext()",        -1);       return;      }     }     else     {      // CryptAcquireContext() failed.      sqlite3_result_error(       context,       "Error: CryptAcquireContext())",       -1);      return;     }    }    // Create Hash object    if ( !CryptCreateHash( hCryptProv, CALG_MD5, 0, 0, &hHash ) )    {     // Error during CryptCreateHash()     sqlite3_result_error(      context,      "Error: CryptCreateHash()",      -1);     return;    }    // Hash the password    if ( !CryptHashData( hHash, pwd, strlen( pwd ), 0 ) )    {     // Error during CryptHashData     sqlite3_result_error(      context,      "Error: CryptHashData()",      -1);     return;    }    // Derive a session key from the hash object    if ( !CryptDeriveKey( hCryptProv, ENCRYPT_ALGORITHM,     hHash, KEYLENGTH, &hKey ) )    {     // Error during CryptDeriveKey     sqlite3_result_error(      context,      "Error: CryptDeriveKey()",      -1);     return;    }    // Decrypt    unsigned long length = strlen(src);    unsigned char *dst = (unsigned char *)malloc(length + 1);    memcpy(dst, src, length + 1 );    if ( !CryptDecrypt( hKey, NULL, TRUE, 0, dst, &length ) )    {     // Error during CryptEncrypt     sqlite3_result_error(      context,      "Error: CryptDecrypt()",      -1);     return;    }    sqlite3_result_blob(     context,     dst,     strlen( dst ),     SQLITE_TRANSIENT );    free( dst );   }  } } //------------------------------------------------------------------------ __fastcall TForm1::TForm1(TComponent* Owner)  : TForm(Owner) {  m_pDB = NULL; } //------------------------------------------------------------------------ void __fastcall TForm1::FormDestroy(TObject *Sender) {  if ( m_pDB )   sqlite3_close( m_pDB ); } //------------------------------------------------------------------------ void __fastcall TForm1::FormCreate(TObject *Sender) {  int nRst = sqlite3_open( "test.db", &m_pDB );  if ( nRst != SQLITE_OK )  {   ShowMessage("Cannot open database.");   return;  }  int nResult;  nResult = sqlite3_create_function(m_pDB, "Encrypt", -1,    SQLITE_UTF8, NULL, &EncryptFunc, NULL, NULL);  nResult = sqlite3_create_function(m_pDB, "Decrypt", -1,    SQLITE_UTF8, NULL, &DecryptFunc, NULL, NULL);  sqlite3_stmt* pStmt = NULL;  const char* szChar;  String strTemp;  String strQuery;  strQuery = "SELECT Encrypt('test', '123')";  if ( sqlite3_prepare( m_pDB, strQuery.c_str(),   strQuery.Length(), &pStmt, &szChar ) == SQLITE_OK )  {   int nRow = sqlite3_data_count( pStmt );   int nCol = sqlite3_column_count( pStmt );   const char* col1name = sqlite3_column_name( pStmt, 0 );   int nRowCnt = 0;   if ( sqlite3_step( pStmt ) == SQLITE_ROW )   {    ++nRowCnt;    const unsigned char* col1 = sqlite3_column_text( pStmt, 0 );    String strMsg;    strMsg.sprintf(     "ROW %d: %s => %s",     nRowCnt, col1name, col1    );    strTemp.sprintf( "%s", col1 );    ShowMessage( strMsg );   }  }  sqlite3_finalize( pStmt );  strQuery = "SELECT Decrypt('" + strTemp + "', '123')";  if ( sqlite3_prepare( m_pDB, strQuery.c_str(),   strQuery.Length(), &pStmt, &szChar ) == SQLITE_OK )  {   int nRow = sqlite3_data_count( pStmt );   int nCol = sqlite3_column_count( pStmt );   const char* col1name = sqlite3_column_name( pStmt, 0 );   int nRowCnt = 0;   if ( sqlite3_step( pStmt ) == SQLITE_ROW )   {    ++nRowCnt;    const unsigned char* col1 = sqlite3_column_text( pStmt, 0 );    String strMsg;    strMsg.sprintf(     "ROW %d: %s => %s",     nRowCnt, col1name, col1    );    ShowMessage( strMsg );   }  }  sqlite3_finalize( pStmt ); } //------------------------------------------------------------------------