freeotfecallmodulefn.c

来自「文件驱动加密,功能强大,可产生加密分区,支持AES,MD2,MD4,MD5MD2」· C语言 代码 · 共 192 行

// Description: FreeOTFE IV Generation
// By Sarah Dean
// Email: [e-mail]
// WWW:   http://www.FreeOTFE.org/
//
// -----------------------------------------------------------------------------
//


#include "FreeOTFECallModuleFn.h"
#include "FreeOTFEPlatform.h"
#include "FreeOTFEDebug.h"
#include "FreeOTFEGenerateBlockIV.h"


// =========================================================================
// =========================================================================
// Call the relevant encryption function
NTSTATUS
BlockEncrypt(
    IN DEVICE_CONTEXT* DeviceContext,
    IN LARGE_INTEGER fileOffset,  // The offset within the *volume file* where the
                                  // data was obtained from
    IN FREEOTFEBYTE* plaintextBuffer,
    IN FREEOTFEBYTE* cyphertextBuffer
)
{
    NTSTATUS status = STATUS_SUCCESS;
    char blockIV[FREEOTFE_MAX_CYPHER_BLOCKSIZE / 8];
    unsigned int blockIVLength;  // In *bits*

    DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_ENTER, (TEXT("BlockEncrypt\n")));

	// Sanity check
    if (DeviceContext->MainCypher.FnEncrypt != NULL)
        {
		// If the blocksize isn't defined, we can't use an IV
		if (DeviceContext->MainCypher.Details.BlockSize > 0) 
			{
			// Note: The block IV length is equal to the block length		
			blockIVLength = DeviceContext->MainCypher.Details.BlockSize;
			status = GenerateBlockIV(
									DeviceContext,
									fileOffset,
									blockIVLength,  // In bits
									(unsigned char*)&blockIV
									);
			if (!(NT_SUCCESS(status)))
				{
				DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("Unable to generate block IV\n")));
				return status;
				}
			}
		else  // ELSE PART - if (DeviceContext->CypherDetails.BlockSize > 0) 
			{
			DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_INFO, (TEXT("Cypher block size is 0; no IV\n")));
			blockIVLength = 0;
			}

		if (NT_SUCCESS(status))
			{
			status = DeviceContext->MainCypher.FnEncrypt(
									   &DeviceContext->MainCypher.CypherGUID,
									   DeviceContext->MasterKeyLength,
									   (char*)DeviceContext->MasterKey,
									   (char*)DeviceContext->MasterKeyASCII,
									   blockIVLength,
									   (char*)&blockIV,
									   DeviceContext->EncryptionBlockSize,
									   plaintextBuffer,
									   cyphertextBuffer
									  );
		    if (!(NT_SUCCESS(status)))
    			{
                DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("Encrypt failed\n")));
                }
			}
        }
    else  // ELSE PART - if (DeviceContext->FnEncrypt != NULL)
        {
        DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("No encryption function...\n")));
        }


	DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_EXIT, (TEXT("BlockEncrypt\n")));
    return status;
}


// =========================================================================
// Call the relevant decryption function
NTSTATUS
BlockDecrypt(
    IN DEVICE_CONTEXT* DeviceContext,
    IN LARGE_INTEGER fileOffset,  // The offset within the *volume file* where the
                                  // data was obtained from
    IN FREEOTFEBYTE* cyphertextBuffer,
    IN FREEOTFEBYTE* plaintextBuffer
)
{
    NTSTATUS status = STATUS_SUCCESS;
    char blockIV[FREEOTFE_MAX_CYPHER_BLOCKSIZE / 8];
    unsigned int blockIVLength;
    
    DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_ENTER, (TEXT("BlockDecrypt\n")));

    if (DeviceContext->MainCypher.FnDecrypt != NULL)
		{
		// If the blocksize isn't defined, we can't use an IV
		if (DeviceContext->MainCypher.Details.BlockSize > 0) 
			{
			// Note: The block IV length is equal to the block length		
			blockIVLength = DeviceContext->MainCypher.Details.BlockSize;
			status = GenerateBlockIV(
									DeviceContext,
									fileOffset,
									blockIVLength,  // In bits
									(unsigned char*)&blockIV
									);
			if (!(NT_SUCCESS(status)))
				{
				DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("Unable to generate block IV\n")));
				return status;
				}
			}
		else  // ELSE PART - if (DeviceContext->CypherDetails.BlockSize > 0) 
			{
			DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_INFO, (TEXT("Cypher block size is 0; no IV\n")));
			blockIVLength = 0;
			}

		if (NT_SUCCESS(status))
			{
			status = DeviceContext->MainCypher.FnDecrypt(
					        	       &DeviceContext->MainCypher.CypherGUID,
        							   DeviceContext->MasterKeyLength,
		        					   (char*)DeviceContext->MasterKey,
				        			   (char*)DeviceContext->MasterKeyASCII,                          
						        	   blockIVLength,
							           (char*)&blockIV,
							           DeviceContext->EncryptionBlockSize,
							           cyphertextBuffer,
							           plaintextBuffer
							          );
		    if (!(NT_SUCCESS(status)))
    			{
                DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("Decrypt failed\n")));
                }
			}
		}
    else  // ELSE PART - if (DeviceContext->FnDecrypt != NULL)
        {
        DEBUGOUTMAINDRV(DEBUGLEV_ERROR, (TEXT("No decryption function...\n")));
        }


    DEBUGOUTMAINDRV(DEBUGLEV_VERBOSE_EXIT, (TEXT("BlockDecrypt\n")));
    return status;
}


// =========================================================================
// Call the relevant hash function
NTSTATUS
DataHash(
    IN      MODULE_DETAILS_HASH* hashModule,
    IN      unsigned int dataLength,  // In bits
    IN      FREEOTFEBYTE* dataBuffer,
    IN OUT  unsigned int* hashLength,  // In bits
    IN      FREEOTFEBYTE* hashBuffer    
)
{
    NTSTATUS retval;

    DEBUGOUTMAINDRV(DEBUGLEV_ENTER, (TEXT("DataHash\n")));

    retval = hashModule->FnHash(
                                &(hashModule->HashGUID),
                                dataLength,
                                dataBuffer,
                                hashLength,
                                hashBuffer
                               );

    DEBUGOUTMAINDRV(DEBUGLEV_EXIT, (TEXT("DataHash\n")));
    return retval;
}


// =========================================================================
// =========================================================================