Orkimede
Bonjour, j’ai un problème sur le TP 15. Mon code est le suivant:
#include <inttypes.h>
#include <stdio.h>
#include <string.h>
/* Add required includes here */
#include "shell.h"
#include "fmt.h"
#include "crypto/ciphers.h"
#include "crypto/modes/ctr.h"
/* Intermediate encryption/decryption buffers */
#define BUF_SIZE (64U)
static uint8_t data[BUF_SIZE] = { 0 };
static char buf_str[BUF_SIZE * 2] = { 0 };
static uint8_t ctr_copy[16];
/* Add here the key and the nonce */
static const uint8_t key[] = {
0x23, 0xA0, 0x18, 0x53, 0xFA, 0xB3, 0x89, 0x23,
0x65, 0x89, 0x2A, 0xBC, 0x43, 0x99, 0xCC, 0x00
};
static const uint8_t ctr[] = {
0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
};
static int _encrypt_handler(int argc, char **argv);
static int _decrypt_handler(int argc, char **argv);
/* Implement the encrypt command handler here */
static int _encrypt_handler(int argc, char **argv)
{
if (argc != 2) {
printf("usage: %s <input to encrypt>\n", argv[0]);
return 1;
}
/* Clear intermediate data buffer */
memset(data, 0, BUF_SIZE);
/* Copy the nonce in memory */
memcpy(ctr_copy, ctr, 16);
/* Encrypt the message */
cipher_t cipher;
cipher_init(&cipher, CIPHER_AES_128, key, sizeof(key));
size_t enc_len = cipher_encrypt_ctr(&cipher, ctr_copy, 0, (uint8_t *)argv[1], strlen(argv[1]), data);
/* Convert the byte array to a string of hex characters */
size_t len = fmt_bytes_hex(buf_str, data, enc_len);
buf_str[len] = 0;
/* Print the result */
printf("%s\n", buf_str);
return 0;
}
/* Implement the decrypt command handler here */
static int _decrypt_handler(int argc, char **argv)
{
if (argc != 2) {
printf("usage: %s <input to decrypt>\n", argv[0]);
return 1;
}
/* Clear intermediate data buffer */
memset(data, 0, BUF_SIZE);
/* Copy the nonce in memory */
memcpy(ctr_copy, ctr, 16);
/* Convert encrypt message from hex string to byte array */
size_t len = fmt_hex_bytes(data, argv[1]);
/* Decrypt the message */
cipher_t cipher;
cipher_init(&cipher, CIPHER_AES_128, key, sizeof(key));
cipher_decrypt_ctr(&cipher, ctr_copy, 0, data, len, (uint8_t *)buf_str);
buf_str[len] = 0;
/* Print the result */
printf("%s\n", buf_str);
return 0;
}
/* Declare the list of shell commands */
static const shell_command_t shell_commands[] = {
{ "encrypt", "Encrypt input string", _encrypt_handler },
{ "decrypt", "Decrypt input string", _decrypt_handler },
{ NULL, NULL, NULL }
};
int main(void)
{
/* Configure and start the shell */
char line_buf[SHELL_DEFAULT_BUFSIZE];
shell_run(shell_commands, line_buf, SHELL_DEFAULT_BUFSIZE);
return 0;
}
Makefile:
APPLICATION = hash
BOARD ?= native
# Add required modules here
USEMODULE += crypto
USEMODULE += cipher_modes
USEMODULE += fmt
USEMODULE += shell
# Specify we are using AES crypto
CFLAGS += -DCRYPTO_AES
RIOTBASE ?= $(CURDIR)/../../RIOT
include $(RIOTBASE)/Makefile.include
Commandes entrées dans la console:
make -C riot/security/encryption
make -C riot/security/encryption term
encrypt riot
retour:
encrypt riot
E7461EA1
Ceci ne correspond donc pas au résultat attendu en sortie (B518FD49). Cela étant dit, je peux décripter le message “E7461EA1” pour récupérer le mot “riot”.
Auriez vous des suggestions pour expliquer cela?
