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/* Copyright 2017 The Chromium OS Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#define __packed __attribute__((packed))
#include "rma_auth.h"
#include "curve25519.h"
#include "sha256.h"
#include "base32.h"
#define SERVER_ADDRESS "https://www.google.com/chromeos/partner/console/cr50reset/request"
/* Server public key and key ID */
static uint8_t server_pri_key[32] = RMA_TEST_SERVER_PRIVATE_KEY;
static uint8_t server_pub_key[32] = RMA_TEST_SERVER_PUBLIC_KEY;
static uint8_t server_key_id = RMA_TEST_SERVER_KEY_ID;
static uint8_t board_id[4] = {'Z', 'Z', 'C', 'R'};
static uint8_t device_id[8] = {'T', 'H', 'X', 1, 1, 3, 8, 0xfe};
static char challenge[RMA_CHALLENGE_BUF_SIZE];
static char authcode[RMA_AUTHCODE_BUF_SIZE];
void panic_assert_fail(const char *fname, int linenum);
void rand_bytes(void *buffer, size_t len);
int safe_memcmp(const void *s1, const void *s2, size_t size);
void panic_assert_fail(const char *fname, int linenum)
{
printf("\nASSERTION FAILURE at %s:%d\n", fname, linenum);
}
int safe_memcmp(const void *s1, const void *s2, size_t size)
{
const uint8_t *us1 = s1;
const uint8_t *us2 = s2;
int result = 0;
if (size == 0)
return 0;
while (size--)
result |= *us1++ ^ *us2++;
return result != 0;
}
void rand_bytes(void *buffer, size_t len)
{
int random_togo = 0;
uint32_t buffer_index = 0;
uint32_t random_value;
uint8_t *buf = (uint8_t *) buffer;
while (buffer_index < len) {
if (!random_togo) {
random_value = rand();
random_togo = sizeof(random_value);
}
buf[buffer_index++] = random_value >>
((random_togo-- - 1) * 8);
}
}
int rma_create_challenge(void)
{
uint8_t temp[32]; /* Private key or HMAC */
uint8_t secret[32];
struct rma_challenge c;
uint8_t *cptr = (uint8_t *)&c;
/* Clear the current challenge and authcode, if any */
memset(challenge, 0, sizeof(challenge));
memset(authcode, 0, sizeof(authcode));
memset(&c, 0, sizeof(c));
c.version_key_id = RMA_CHALLENGE_VKID_BYTE(
RMA_CHALLENGE_VERSION, server_key_id);
memcpy(c.board_id, board_id, sizeof(c.board_id));
memcpy(c.device_id, device_id, sizeof(c.device_id));
/* Calculate a new ephemeral key pair */
X25519_keypair(c.device_pub_key, temp);
/* Encode the challenge */
if (base32_encode(challenge, sizeof(challenge), cptr, 8 * sizeof(c), 9))
return 1;
/* Calculate the shared secret */
X25519(secret, temp, server_pub_key);
/*
* Auth code is a truncated HMAC of the ephemeral public key, BoardID,
* and DeviceID. Those are all in the right order in the challenge
* struct, after the version/key id byte.
*/
hmac_SHA256(temp, secret, sizeof(secret), cptr + 1, sizeof(c) - 1);
if (base32_encode(authcode, sizeof(authcode), temp,
RMA_AUTHCODE_CHARS * 5, 0))
return 1;
return 0;
}
int rma_try_authcode(const char *code)
{
return safe_memcmp(authcode, code, RMA_AUTHCODE_CHARS);
}
static void print_params(void)
{
int i;
printf("\nBoard Id:\n");
for (i = 0; i < 4; i++)
printf("%c ", board_id[i]);
printf("\n\nDevice Id:\n");
for (i = 0; i < 3; i++)
printf("%c ", device_id[i]);
for (i = 3; i < 8; i++)
printf("%02x ", device_id[i]);
printf("\n\nServer Key Id:\n");
printf("%02x", server_key_id);
printf("\n\nServer Private Key:\n");
for (i = 0; i < 32; i++)
printf("%02x%c", server_pri_key[i], ((i + 1) % 8) ? ' ':'\n');
printf("\nServer Public Key:\n");
for (i = 0; i < 32; i++)
printf("%02x%c", server_pub_key[i], ((i + 1) % 8) ? ' ':'\n');
printf("\nChallenge:\n");
for (i = 0; i < RMA_CHALLENGE_CHARS; i++) {
printf("%c", challenge[i]);
if (((i + 1) % 5) == 0)
printf(" ");
if (((i + 1) % 40) == 0)
printf("\n");
}
printf("\nAuthorization Code:\n");
for (i = 0; i < RMA_AUTHCODE_BUF_SIZE; i++)
printf("%c", authcode[i]);
printf("\n\nChallenge String:\n");
printf("%s?challenge=", SERVER_ADDRESS);
for (i = 0; i < RMA_CHALLENGE_CHARS; i++)
printf("%c", challenge[i]);
printf("&hwid=HWIDTEST2082\n");
printf("\n");
}
int main(int argc, char **argv)
{
char code[25];
int ret;
rma_create_challenge();
print_params();
do {
printf("Enter Authorization Code: ");
fgets(code, 25, stdin);
ret = rma_try_authcode(code);
if (ret != 0)
printf("\n\nCode is invalid\n\n");
} while (ret != 0);
printf("Code Accepted\n");
return 0;
}
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