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Bootloader: optimize code size in single cipher mode by manually inlining EAInit, EAGetFirst and EAGetKeySize, and by removing the loop in ReadVolumeHeader that tests for encryption algorithms.

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This commit is contained in:
Mounir IDRASSI 2014-10-26 00:33:18 +02:00
parent c61f8c70de
commit c1378f781a
3 changed files with 61 additions and 26 deletions
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27
src/Common/Crypto.c
View File

@ -965,20 +965,11 @@ void DecipherBlock(int cipher, void *data, void *ks)
#endif
}
int EAGetFirst ()
{
return 1;
}
int EAGetNext (int previousEA)
{
return 0;
}
int EAInit (int ea, unsigned char *key, unsigned __int8 *ks)
{
#ifdef TC_WINDOWS_BOOT_AES
int EAInit (unsigned char *key, unsigned __int8 *ks)
{
aes_init();
if (aes_encrypt_key256 (key, (aes_encrypt_ctx *) ks) != EXIT_SUCCESS)
@ -986,23 +977,11 @@ int EAInit (int ea, unsigned char *key, unsigned __int8 *ks)
if (aes_decrypt_key256 (key, (aes_decrypt_ctx *) (ks + sizeof (aes_encrypt_ctx))) != EXIT_SUCCESS)
return ERR_CIPHER_INIT_FAILURE;
#elif defined (TC_WINDOWS_BOOT_SERPENT)
serpent_set_key (key, ks);
#elif defined (TC_WINDOWS_BOOT_TWOFISH)
twofish_set_key ((TwofishInstance *)ks, (const u4byte *)key);
#endif
return ERR_SUCCESS;
}
int EAGetKeySize (int ea)
{
return 32;
}
#endif
int EAGetFirstCipher (int ea)
{
return 1;
}
void EncryptBuffer (unsigned __int8 *buf, TC_LARGEST_COMPILER_UINT len, PCRYPTO_INFO cryptoInfo)
{

4
src/Common/Crypto.h
View File

@ -259,7 +259,11 @@ const
char * CipherGetName (int cipher);
int CipherInit (int cipher, unsigned char *key, unsigned char *ks);
#ifndef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
int EAInit (int ea, unsigned char *key, unsigned char *ks);
#else
int EAInit (unsigned char *key, unsigned char *ks);
#endif
BOOL EAInitMode (PCRYPTO_INFO ci);
void EncipherBlock(int cipher, void *data, void *ks);
void DecipherBlock(int cipher, void *data, void *ks);

56
src/Common/Volumes.c
View File

@ -558,7 +558,7 @@ int ReadVolumeHeader (BOOL bBoot, char *header, Password *password, PCRYPTO_INFO
#endif
PCRYPTO_INFO cryptoInfo;
int status;
int status = ERR_SUCCESS;
if (retHeaderCryptoInfo != NULL)
cryptoInfo = retHeaderCryptoInfo;
@ -577,15 +577,40 @@ int ReadVolumeHeader (BOOL bBoot, char *header, Password *password, PCRYPTO_INFO
// Mode of operation
cryptoInfo->mode = FIRST_MODE_OF_OPERATION_ID;
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
cryptoInfo->ea = 1;
#else
// Test all available encryption algorithms
for (cryptoInfo->ea = EAGetFirst (); cryptoInfo->ea != 0; cryptoInfo->ea = EAGetNext (cryptoInfo->ea))
#endif
{
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
#if defined (TC_WINDOWS_BOOT_SERPENT)
serpent_set_key (dk, cryptoInfo->ks);
#elif defined (TC_WINDOWS_BOOT_TWOFISH)
twofish_set_key ((TwofishInstance *) cryptoInfo->ks, (const u4byte *) dk);
#else
status = EAInit (dk, cryptoInfo->ks);
if (status == ERR_CIPHER_INIT_FAILURE)
goto err;
#endif
#else
status = EAInit (cryptoInfo->ea, dk, cryptoInfo->ks);
if (status == ERR_CIPHER_INIT_FAILURE)
goto err;
#endif
// Secondary key schedule
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
#if defined (TC_WINDOWS_BOOT_SERPENT)
serpent_set_key (dk + 32, cryptoInfo->ks2);
#elif defined (TC_WINDOWS_BOOT_TWOFISH)
twofish_set_key ((TwofishInstance *)cryptoInfo->ks2, (const u4byte *) (dk + 32));
#else
EAInit (dk + 32, cryptoInfo->ks2);
#endif
#else
EAInit (cryptoInfo->ea, dk + EAGetKeySize (cryptoInfo->ea), cryptoInfo->ks2);
#endif
// Try to decrypt header
DecryptBuffer (header + HEADER_ENCRYPTED_DATA_OFFSET, HEADER_ENCRYPTED_DATA_SIZE, cryptoInfo);
@ -596,7 +621,12 @@ int ReadVolumeHeader (BOOL bBoot, char *header, Password *password, PCRYPTO_INFO
|| GetHeaderField32 (header, TC_HEADER_OFFSET_KEY_AREA_CRC) != GetCrc32 (header + HEADER_MASTER_KEYDATA_OFFSET, MASTER_KEYDATA_SIZE))
{
EncryptBuffer (header + HEADER_ENCRYPTED_DATA_OFFSET, HEADER_ENCRYPTED_DATA_SIZE, cryptoInfo);
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
status = ERR_PASSWORD_WRONG;
goto err;
#else
continue;
#endif
}
// Header decrypted
@ -629,12 +659,34 @@ int ReadVolumeHeader (BOOL bBoot, char *header, Password *password, PCRYPTO_INFO
goto ret;
// Init the encryption algorithm with the decrypted master key
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
#if defined (TC_WINDOWS_BOOT_SERPENT)
serpent_set_key (masterKey, cryptoInfo->ks);
#elif defined (TC_WINDOWS_BOOT_TWOFISH)
twofish_set_key ((TwofishInstance *) cryptoInfo->ks, (const u4byte *) masterKey);
#else
status = EAInit (masterKey, cryptoInfo->ks);
if (status == ERR_CIPHER_INIT_FAILURE)
goto err;
#endif
#else
status = EAInit (cryptoInfo->ea, masterKey, cryptoInfo->ks);
if (status == ERR_CIPHER_INIT_FAILURE)
goto err;
#endif
// The secondary master key (if cascade, multiple concatenated)
#ifdef TC_WINDOWS_BOOT_SINGLE_CIPHER_MODE
#if defined (TC_WINDOWS_BOOT_SERPENT)
serpent_set_key (masterKey + 32, cryptoInfo->ks2);
#elif defined (TC_WINDOWS_BOOT_TWOFISH)
twofish_set_key ((TwofishInstance *)cryptoInfo->ks2, (const u4byte *) (masterKey + 32));
#else
EAInit (masterKey + 32, cryptoInfo->ks2);
#endif
#else
EAInit (cryptoInfo->ea, masterKey + EAGetKeySize (cryptoInfo->ea), cryptoInfo->ks2);
#endif
goto ret;
}