Vault 7: Projects
This publication series is about specific projects related to the Vault 7 main publication.
File
block_cipher_mode_cbc.h
Syntax
void BLOCK_CIPHER_CBC_Decrypt(DRV_HANDLE handle, uint8_t * plainText, uint32_t *
numPlainBytes, uint8_t * cipherText, uint32_t numCipherBytes, void * key,
BLOCK_CIPHER_CBC_CONTEXT * context, uint32_t options);
Module
CBC
Returns
None
Description
Decrypts cipher text using cipher-block chaining mode.
Preconditions
The CBC context must be initialized with the block cipher encrypt/decrypt functions and the block cipher algorithm's block
size. The block cipher module must be initialized, if necessary.
Example
// ***************************************************************
// Decrypt data in CBC mode with the AES algorithm.
// ***************************************************************
// System module object variable (for initializing AES)
SYS_MODULE_OBJ sysObject;
// Drive handle variable, to describe which AES module to use
DRV_HANDLE handle;
// CBC mode context
BLOCK_CIPHER_CBC_CONTEXT context;
// Initialization vector for CBC mode
static uint8_t initialization_vector[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};
// Cipher text to decrypt
static uint8_t cipher_text[] = { 0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9,
0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e,
0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5,
0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad,
0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10};
// The encryption key
static uint8_t AESKey128[] = {0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7,
0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c};
// Structure to contain the created AES round keys
AES_ROUND_KEYS_128_BIT round_keys;
// Buffer to contain encrypted plaintext
uint8_t plain_text[sizeof(cipher_text)];
// The number of bytes that were decrypted
uint32_t num_bytes_decrypted;
// Initialization call for the AES module
sysObject = DRV_AES_Initialize (DRV_AES_INDEX, NULL);
if (sysObject != SYS_MODULE_OBJ_STATIC)
{
// error
}
// Driver open call for the AES module
1.7 Library Interface MLA - Crypto Library Help Block Cipher Modes
47
Protego_Release_01_05-Related-OEM-Documentation-MLA_v2013_12_20-help_mla_crypto.pdf