// Returns sum of key sizes of all ciphers of the EA (in bytes)
int EAGetKeySize (int ea)
{
int i = EAGetFirstCipher (ea);
int size = CipherGetKeySize (i);
while (i = EAGetNextCipher (ea, i))
{
size += CipherGetKeySize (i);
}
return size;
}
/* Return values: 0 = success, ERR_CIPHER_INIT_FAILURE (fatal), ERR_CIPHER_INIT_WEAK_KEY (non-fatal) */
int CipherInit (int cipher, unsigned char *key, unsigned __int8 *ks)
{
int retVal = ERR_SUCCESS;
switch (cipher)
{
case AES:
#ifndef TC_WINDOWS_BOOT
if (aes_encrypt_key256 (key, (aes_encrypt_ctx *) ks) != EXIT_SUCCESS)
return ERR_CIPHER_INIT_FAILURE;
if (aes_decrypt_key256 (key, (aes_decrypt_ctx *) (ks + sizeof(aes_encrypt_ctx))) != EXIT_SUCCESS)
return ERR_CIPHER_INIT_FAILURE;
#else
if (aes_set_key (key, (length_type) CipherGetKeySize(AES), (aes_context *) ks) != 0)
return ERR_CIPHER_INIT_FAILURE;
#endif
break;
case SERPENT:
serpent_set_key (key, ks);
break;
case TWOFISH:
twofish_set_key ((TwofishInstance *)ks, (const u4byte *)key);
break;
default:
// Unknown/wrong cipher ID
return ERR_CIPHER_INIT_FAILURE;
}
return retVal;
}
/* Return values: 0 = success, ERR_CIPHER_INIT_FAILURE (fatal), ERR_CIPHER_INIT_WEAK_KEY (non-fatal) */
int CipherInit (int cipher, unsigned char *key, unsigned __int8 *ks)
{
int retVal = ERR_SUCCESS;
switch (cipher)
{
case AES:
#ifndef TC_WINDOWS_BOOT
if (aes_encrypt_key256 (key, (aes_encrypt_ctx *) ks) != EXIT_SUCCESS)
return ERR_CIPHER_INIT_FAILURE;
if (aes_decrypt_key256 (key, (aes_decrypt_ctx *) (ks + sizeof(aes_encrypt_ctx))) != EXIT_SUCCESS)
return ERR_CIPHER_INIT_FAILURE;
#else
if (aes_set_key (key, (length_type) CipherGetKeySize(AES), (aes_context *) ks) != 0)
return ERR_CIPHER_INIT_FAILURE;
#endif
break;
case SERPENT:
serpent_set_key (key, CipherGetKeySize(SERPENT) * 8, ks);
break;
case TWOFISH:
twofish_set_key ((TwofishInstance *)ks, (const u4byte *)key, CipherGetKeySize(TWOFISH) * 8);
break;
#ifndef TC_WINDOWS_BOOT
case BLOWFISH:
/* Deprecated/legacy */
BlowfishSetKey ((BF_KEY *)ks, CipherGetKeySize(BLOWFISH), key);
break;
case CAST:
/* Deprecated/legacy */
Cast5SetKey ((CAST_KEY *) ks, CipherGetKeySize(CAST), key);
break;
case TRIPLEDES:
/* Deprecated/legacy */
TripleDesSetKey (key, CipherGetKeySize (TRIPLEDES), (TDES_KEY *) ks);
// Verify whether all three DES keys are mutually different
if (((*((__int64 *) key) ^ *((__int64 *) key+1)) & 0xFEFEFEFEFEFEFEFEULL) == 0
|| ((*((__int64 *) key+1) ^ *((__int64 *) key+2)) & 0xFEFEFEFEFEFEFEFEULL) == 0
|| ((*((__int64 *) key) ^ *((__int64 *) key+2)) & 0xFEFEFEFEFEFEFEFEULL) == 0)
retVal = ERR_CIPHER_INIT_WEAK_KEY; // Non-fatal error
break;
#endif // TC_WINDOWS_BOOT
default:
// Unknown/wrong cipher ID
return ERR_CIPHER_INIT_FAILURE;
}
return retVal;
}
// Return values: 0 = success, ERR_CIPHER_INIT_FAILURE (fatal), ERR_CIPHER_INIT_WEAK_KEY (non-fatal)
int EAInit (int ea, unsigned char *key, unsigned __int8 *ks)
{
int c, retVal = ERR_SUCCESS;
if (ea == 0)
return ERR_CIPHER_INIT_FAILURE;
for (c = EAGetFirstCipher (ea); c != 0; c = EAGetNextCipher (ea, c))
{
switch (CipherInit (c, key, ks))
{
case ERR_CIPHER_INIT_FAILURE:
return ERR_CIPHER_INIT_FAILURE;
case ERR_CIPHER_INIT_WEAK_KEY:
retVal = ERR_CIPHER_INIT_WEAK_KEY; // Non-fatal error
break;
}
key += CipherGetKeySize (c);
ks += CipherGetKeyScheduleSize (c);
}
return retVal;
}
