2025-11-28 00:35:46 +09:00

585 lines
19 KiB
C++

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved.
/****************************************************************
Title: Encrypting Data and creating an enveloped message
This example shows how to encrypt and decrypt a PKCS7 / CMS message.
It illustrates use of the CryptEncryptMessage and CryptDecryptMessage API.
****************************************************************/
#define CRYPT_OID_INFO_HAS_EXTRA_FIELDS
#include <windows.h>
#include <winerror.h>
#include <strsafe.h>
#include <wincrypt.h>
#include <stdio.h>
/*****************************************************************************
ReportError
Prints error information to the console
*****************************************************************************/
void
ReportError(
LPCWSTR wszMessage,
DWORD dwErrCode
)
{
LPWSTR pwszMsgBuf = NULL;
if( NULL!=wszMessage && 0!=*wszMessage )
{
wprintf( L"%s\n", wszMessage );
}
FormatMessageW(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM,
NULL, // Location of message
// definition ignored
dwErrCode, // Message identifier for
// the requested message
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Language identifier for
// the requested message
(LPWSTR) &pwszMsgBuf, // Buffer that receives
// the formatted message
0, // Size of output buffer
// not needed as allocate
// buffer flag is set
NULL // Array of insert values
);
if( NULL != pwszMsgBuf )
{
wprintf( L"Error: 0x%08x (%d) %s\n", dwErrCode, dwErrCode, pwszMsgBuf );
LocalFree(pwszMsgBuf);
}
else
{
wprintf( L"Error: 0x%08x (%d)\n", dwErrCode, dwErrCode );
}
}
/*****************************************************************************
HrLoadFile
Load file into allocated (*ppbData).
The caller must free the memory by LocalFree().
*****************************************************************************/
HRESULT
HrLoadFile(
LPCWSTR wszFileName,
PBYTE *ppbData,
DWORD *pcbData
)
{
HANDLE hFile = INVALID_HANDLE_VALUE;
DWORD cbRead = 0;
HRESULT hr = S_OK;
*ppbData = NULL;
*pcbData = 0;
hFile = CreateFileW( wszFileName,
GENERIC_READ,
0,
NULL,
OPEN_EXISTING,
0,
NULL );
if( INVALID_HANDLE_VALUE == hFile )
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
*pcbData = GetFileSize( hFile, NULL );
if( *pcbData == 0 )
{
hr = S_FALSE;
goto CleanUp;
}
*ppbData = (PBYTE)LocalAlloc( LPTR, *pcbData );
if( NULL == *ppbData )
{
hr = HRESULT_FROM_WIN32( ERROR_OUTOFMEMORY );
goto CleanUp;
}
if( !ReadFile( hFile, *ppbData, *pcbData, &cbRead, NULL ))
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
CleanUp:
if (hFile != INVALID_HANDLE_VALUE )
{
CloseHandle(hFile);
}
if( FAILED(hr) )
{
if( NULL != *ppbData )
{
LocalFree( *ppbData );
}
*ppbData = NULL;
*pcbData = 0;
}
return hr;
}
/*****************************************************************************
HrSaveFile
*****************************************************************************/
HRESULT
HrSaveFile(
LPCWSTR wszFileName,
PBYTE pbData,
DWORD cbData
)
{
HANDLE hFile = INVALID_HANDLE_VALUE;
HRESULT hr = S_OK;
DWORD cbWritten = 0;
hFile = CreateFileW( wszFileName,
GENERIC_WRITE,
0,
NULL,
CREATE_ALWAYS,
0,
NULL );
if( INVALID_HANDLE_VALUE == hFile )
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
if( !WriteFile( hFile, pbData, cbData, &cbWritten, NULL ))
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
CleanUp:
if (hFile != INVALID_HANDLE_VALUE )
{
CloseHandle(hFile);
}
return hr;
}
/*****************************************************************************
Usage
*****************************************************************************/
void
Usage(
LPCWSTR wsName
)
{
wprintf( L"%s [Options] {COMMAND}\n", wsName );
wprintf( L" Options:\n" );
wprintf( L" -s {STORENAME} : store name, (by default MY)\n" );
wprintf( L" -n {SubjectName} : Recepient certificate's CN to search for.\n" );
wprintf( L" (by default \"Test\")\n" );
wprintf( L" -a {CNGAlgName} : Encryption algorithm, (by default AES128)\n" );
wprintf( L" -k {KeySize} : Encryption key size in bits, (by default 128)\n" );
wprintf( L" COMMANDS:\n" );
wprintf( L" ENCRYPT {inputfile} {outputfile}\n" );
wprintf( L" | Encrypt message\n" );
wprintf( L" DECRYPT {inputfile} {outputfile}\n" );
wprintf( L" | Decrypt message\n" );
}
/*****************************************************************************
wmain
*****************************************************************************/
DWORD
__cdecl
wmain(
int argc,
LPWSTR argv[]
)
{
HRESULT hr = S_OK;
BOOL fEncrypt = TRUE;
LPCWSTR pwszInputFile = NULL;
LPCWSTR pwszOutputFile = NULL;
BYTE *pbInput = NULL;
DWORD cbInput = 0;
BYTE *pbOutput = NULL;
DWORD cbOutput = 0;
PCCERT_CONTEXT pRecipientCert = NULL;
HCERTSTORE hStoreHandle = NULL;
LPCWSTR pwszStoreName = L"MY"; // by default
LPCWSTR pwszCName = L"Test"; // by default
LPCWSTR pwszAlgName = L"AES128";
ULONG cKeySize = 128;
int i;
//
// options
//
for( i=1; i<argc; i++ )
{
if ( lstrcmpW (argv[i], L"/?") == 0 ||
lstrcmpW (argv[i], L"-?") == 0 )
{
Usage( L"cms_encrypt.exe" );
goto CleanUp;
}
if( *argv[i] != L'-' )
break;
if ( lstrcmpW (argv[i], L"-s") == 0 )
{
if( i+1 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
pwszStoreName = argv[++i];
}
else
if ( lstrcmpW (argv[i], L"-n") == 0 )
{
if( i+1 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
pwszCName = argv[++i];
}
else
if ( lstrcmpW (argv[i], L"-a") == 0 )
{
if( i+1 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
pwszAlgName = argv[++i];
}
else
if ( lstrcmpW (argv[i], L"-k") == 0 )
{
if( i+1 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
cKeySize = (ULONG)wcstoul( argv[++i], NULL, 0);
}
}
if( 0 == lstrcmpW (argv[i], L"ENCRYPT"))
{
if( i+2 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
fEncrypt = TRUE;
pwszInputFile = argv[++i];
pwszOutputFile = argv[++i];
}
else
if( 0 == lstrcmpW (argv[i], L"DECRYPT"))
{
if( i+2 >= argc )
{
hr = E_INVALIDARG;
goto CleanUp;
}
fEncrypt = FALSE;
pwszInputFile = argv[++i];
pwszOutputFile = argv[++i];
}
else
{
hr = E_INVALIDARG;
goto CleanUp;
}
if( i != argc-1 )
{
hr = E_INVALIDARG;
goto CleanUp;
}
//-------------------------------------------------------------------
// Open the certificate store to be searched.
hStoreHandle = CertOpenStore(
CERT_STORE_PROV_SYSTEM, // the store provider type
0, // the encoding type is not needed
NULL, // use the default HCRYPTPROV
CERT_SYSTEM_STORE_CURRENT_USER, // set the store location in a
// registry location
pwszStoreName
); // the store name
if( NULL == hStoreHandle )
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
//
// Load file
//
hr = HrLoadFile(
pwszInputFile,
&pbInput,
&cbInput
);
if( FAILED(hr) )
{
wprintf( L"Unable to read file: %s\n", pwszInputFile );
goto CleanUp;
}
if( fEncrypt )
{
CRYPT_ENCRYPT_MESSAGE_PARA EncryptParams = {0};
//-------------------------------------------------------------------
// Get a certificate that has the specified Subject Name
pRecipientCert = CertFindCertificateInStore(
hStoreHandle,
X509_ASN_ENCODING , // Use X509_ASN_ENCODING
0, // No dwFlags needed
CERT_FIND_SUBJECT_STR, // Find a certificate with a
// subject that matches the
// string in the next parameter
pwszCName, // The Unicode string to be found
// in a certificate's subject
NULL); // NULL for the first call to the
// function; In all subsequent
// calls, it is the last pointer
// returned by the function
if( NULL == pRecipientCert )
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
//-------------------------------------------------------------------
// Initialize the CRYPT_ENCRYPT_MESSAGE_PARA structure.
EncryptParams.cbSize = sizeof(EncryptParams);
EncryptParams.dwMsgEncodingType = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING;
EncryptParams.hCryptProv = NULL;
//-------------------------------------------------------------------
// Find Content Encryption Algorithm OID
EncryptParams.ContentEncryptionAlgorithm.pszObjId = NULL;
PCCRYPT_OID_INFO pOidInfo = CryptFindOIDInfo(
CRYPT_OID_INFO_NAME_KEY,
(void*)pwszAlgName,
CRYPT_ENCRYPT_ALG_OID_GROUP_ID |
(cKeySize << CRYPT_OID_INFO_OID_GROUP_BIT_LEN_SHIFT)
);
if( NULL == pOidInfo )
{
hr = CRYPT_E_UNKNOWN_ALGO;
wprintf( L"FAILED: Unknown algorithm: '%s'.\n", pwszAlgName );
goto CleanUp;
}
EncryptParams.ContentEncryptionAlgorithm.pszObjId = (LPSTR) pOidInfo->pszOID;
//-------------------------------------------------------------------
// Call CryptEncryptMessage.
if( !CryptEncryptMessage(
&EncryptParams, // Pointer to encryption parameters
1, // Number of elements in the CertArray
&pRecipientCert, // Array of pointers to recipient certificates
pbInput, // Pointer to message to be encrypted
cbInput, // Size of message to be encrypted
NULL, // Pointer to encrypted content
&cbOutput)) // Size of encrypted content
{
hr = HRESULT_FROM_WIN32( GetLastError() );
wprintf( L"FAILED: CryptEncryptMessage\n" );
goto CleanUp;
}
//-------------------------------------------------------------------
// Allocate memory for the returned BLOB.
pbOutput = (BYTE*)LocalAlloc( LPTR, cbOutput );
if( NULL == pbOutput )
{
hr = HRESULT_FROM_WIN32( ERROR_OUTOFMEMORY );
goto CleanUp;
}
//-------------------------------------------------------------------
// Call CryptEncryptMessage again to encrypt the content.
if( !CryptEncryptMessage(
&EncryptParams, // Pointer to encryption parameters
1, // Number of elements in the CertArray
&pRecipientCert, // Array of pointers to recipient certificates
pbInput, // Pointer to message to be encrypted
cbInput, // Size of message to be encrypted
pbOutput, // Pointer to encrypted content
&cbOutput)) // Size of encrypted content
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
wprintf( L"Successfully encrypted message using CryptEncryptMessage.\n");
}
else
{
//-------------------------------------------------------------------
// Initialize the CRYPT_DECRYPT_MESSAGE_PARA structure.
CRYPT_DECRYPT_MESSAGE_PARA DecryptParams = {0};
DecryptParams.cbSize = sizeof(DecryptParams);
DecryptParams.dwMsgAndCertEncodingType = X509_ASN_ENCODING | PKCS_7_ASN_ENCODING;
DecryptParams.cCertStore = 1;
DecryptParams.rghCertStore = &hStoreHandle;
//-------------------------------------------------------------------
// Decrypt the message data.
// Call CryptDecryptMessage to get the returned data size.
if( !CryptDecryptMessage(
&DecryptParams, // Pointer to decryption parameters
pbInput, // Pointer to encrypted content
cbInput, // Size of encrypted content
NULL, // Pointer to decrypted message
&cbOutput, // Size of decrypted message
NULL)) // Pointer to certificate that corresponds
// to private exchange key for decryption
{
hr = HRESULT_FROM_WIN32( GetLastError() );
wprintf( L"FAILED: CryptDecryptMessage\n" );
goto CleanUp;
}
//-------------------------------------------------------------------
// Allocate memory for the returned decrypted data.
pbOutput = (BYTE*)LocalAlloc( LPTR, cbOutput );
if( NULL == pbOutput )
{
hr = HRESULT_FROM_WIN32( ERROR_OUTOFMEMORY );
goto CleanUp;
}
//-------------------------------------------------------------------
// Call CryptDecryptMessage to decrypt the data.
if( !CryptDecryptMessage(
&DecryptParams, // Pointer to decryption parameters
pbInput, // Pointer to encrypted content
cbInput, // Size of encrypted content
pbOutput, // Pointer to decrypted message
&cbOutput, // Size of decrypted message
NULL)) // Pointer to certificate that corresponds
// to private exchange key for decryption
{
hr = HRESULT_FROM_WIN32( GetLastError() );
goto CleanUp;
}
wprintf( L"Successfully decrypted message using CryptDecryptMessage.\n");
}
hr = HrSaveFile(
pwszOutputFile,
pbOutput,
cbOutput
);
if( FAILED(hr) )
{
wprintf( L"Unable to save file: %s\n", pwszOutputFile );
goto CleanUp;
}
hr = S_OK;
//-------------------------------------------------------------------
// Clean up memory.
CleanUp:
if( NULL != pbInput )
LocalFree(pbInput);
if( NULL != pbOutput )
LocalFree(pbOutput);
if( NULL != pRecipientCert )
CertFreeCertificateContext(pRecipientCert);
if( NULL != hStoreHandle)
CertCloseStore( hStoreHandle, 0 );
if( FAILED( hr ))
{
ReportError( NULL, hr );
}
return (DWORD)hr;
} // End of main